0001854270-24-000029 | 10-K | XBRL Viewer

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Revenue	12 Months Ended
Revenue	Dec. 31, 2023
Revenue From and Not From Contracts [Abstract]
Revenue	Revenue The Company’s revenue consists of amounts received related to research services provided to customers. Contract Revenue In April 2021, the Company entered into a research collaboration and license agreement with Spark Therapeutics, Inc. (“Spark”). Under the agreement, the Company will be responsible for a research program, which includes designing, building and testing five cell type specific-synthetic promoters for use in developing certain gene therapies using the Company’s proprietary technology. The Company received an upfront payment from Spark of $3.0 million and Spark is obligated to reimburse the Company for costs and expenses incurred for the research program. The Company expected to complete the research program over a two-year period. The Company assessed this agreement in accordance with ASC 606, Revenue Recognition (“ASC 606”) and concluded that the contract counterparty, Spark, is a customer. The Company identified only one combined performance obligation in the agreement, which is to perform research services, the related joint research plan and committees for the five specified promoters. The Company determined that the research activities for each of the five promoters are not distinct given there is one single research plan that is performed by the same research team and research results for one promoter may provide insights for other promoters. Pursuant to the agreement, once the research program is completed and the Company delivers a data package to Spark, Spark has 24 months (the “Evaluation Period”) to determine whether Spark will exercise its options to obtain field-limited, royalty-bearing licenses to develop, manufacture and commercialize promoters corresponding to each of the five specified promoters being researched. For each licensed promoter option that is exercised, the Company is eligible to receive a license fee, potential research, development and commercial milestone payments and royalties on product sales. Spark may generally terminate the agreement upon 90 days prior written notice or 180 days prior written notice if the licensed promoter is in clinical trials or is being commercialized at the time of termination. The Company evaluated Spark’s optional rights to license, develop, manufacture and commercialize each of the promoter profiles to determine whether they provide Spark with any material rights to purchase the promoter licenses at an incremental discount. The Company’s proprietary technology used to develop the promoters is in the early stages of development, so technological feasibility and probability of developing a product is highly uncertain. As a result, determining the SSP for the optional rights is subject to significant judgment. Given the subjectivity associated with determining the SSP for the right to a future license related to unproven technology at contract inception, the Company also evaluated whether the contract consideration associated with the research services represents the SSP for those services. The Company determined the transaction price, inclusive of the upfront payment and reimbursement of costs and expenses incurred for the research program, is commensurate with SSP for the research being conducted given the specialized nature and reliance on proprietary technology. Based on the Company’s assessment of the optional consideration and the qualitative factors of feasibility and probability of development combined with the quantitative assessment that research services are priced at their SSP, the Company concluded that the license option does not provide Spark with an incremental discount and therefore does not constitute a material right. The transaction price associated with the research services in this agreement consists of the fixed upfront amount of $3.0 million and variable consideration. For the Spark collaboration agreement, the Company will recognize the transaction price as research and development services are provided, using a cost-based input method to measure the progress toward completion of its performance obligation and to calculate the corresponding amount of revenue to recognize each period. The Company believes that the cost-based input method is the best measure of progress because other measurements would not reflect how the Company transfers the control related to the performance obligation to our customers. In December 2022, the Company amended the research collaboration and license agreement to allow for an increase in budget and a two-month extension of the research program. As there were no changes to performance obligations and the services to be provided are not distinct from those already transferred, the transactions was accounted for as a contract modification and a cumulative catch-up of $(0.7) million was recognized in December 2022. In May 2023, the Company amended the research collaboration and license agreement with Spark to allow for an increase in budget and additional two-month extension of the research program. As there were no changes to performance obligations and the services to be provided are not distinct from those already transferred, the transaction was accounted for as a contract modification with no cumulative catch-up necessary. In July 2023, the Company completed the research program under the research collaboration and license agreement with Spark and the remaining upfront payment was recognized. As of December 31, 2023 there was no remaining upfront payment and as of December 31, 2022 there was $0.8 million remaining of the upfront payment to be recognized over the remaining period of the research program. In November 2023, the Company entered into a Collaboration and Option Agreement with Celest Therapeutics (Shanghai) Co. Ltd. (“Celest”). Subject to the terms and conditions of the Agreement, the Company and Celest will enter into a collaboration under which Celest will lead a pilot trial of a candidate product for the SENTI-301A program in mainland China, with certain technical support from the Company. In addition, the Company agreed to grant an exclusive option to enter a license agreement with Celest to research, develop, manufacture and commercialize SENTI-301A in mainland China, Hong Kong, Macau, and Taiwan. Outside of these jurisdictions, the Company would retain its rights in the SENTI-301A program. Pursuant to the Agreement, with the exercise of the option and entering into a license agreement, the Company may become eligible to receive certain option exercise fee and milestone payments, in an aggregate amount of $156.0 million, as well as certain tiered royalty payments. For the years ended December 31, 2023 and 2022, the Company recorded revenue, which was previously included in the deferred revenue at the beginning of each period, of $0.8 million and $1.0 million, respectively. Grant Income In 2021, the Small Business Innovation Research (“SBIR”) awarded the Company a grant in the amount of $2.0 million over two years subject to meeting certain terms and conditions. The purpose of the grant is to support the further development of SENTI-202 for acute myeloid leukemia towards clinical development. Grant income was recognized when qualified research and development costs were incurred and the Company obtained reasonable assurance that the terms and conditions of the grant were met. In August 2023, the Company completed the research and development project which was the subject of the SBIR grant. Entity-wide information During both years ended December 31, 2023 and 2022, Customers A and B accounted for 77% and 23%, respectively, of revenue. All revenues were generated in the United States for the years ended December 31, 2023 and 2022.

Stock-Based Compensation - Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Number of Options
Outstanding, beginning of period (in shares)	4,191,426
Granted (in shares)	2,914,196
Forfeited (in shares)	(869,943)
Outstanding, end of period (in shares)	6,235,679	4,191,426
Vested and exercisable (in shares)	2,270,135
Weighted-Average Exercise Price
Outstanding, beginning of period (in dollars per share)	$ 3.18
Granted (in dollars per share)	1.60
Forfeited (in dollars per share)	3.33
Outstanding, end of period (in dollars per share)	2.42	$ 3.18
Vested and exercisable (in shares)	$ 3.00
Stock Options Additional Disclosures
Outstanding, beginning of period, Weighted average remaining contractual life (Years)	7 years 2 months 12 days	9 years 1 month 6 days
Outstanding, end of period, Weighted average remaining contractual life (Years)	7 years 2 months 12 days	9 years 1 month 6 days
Vested and exercisable, Weighted average remaining contractual life (Years)	6 years 8 months 12 days
Outstanding, beginning of period, aggregate intrinsic value	$ 2	$ 6
Outstanding, end of period, aggregate intrinsic value	2	$ 6
Vested and exercisable, aggregate intrinsic value	$ 2

Operating Leases (Tables)

12 Months Ended

Dec. 31, 2023

Leases [Abstract]

Lease, Cost

A summary of total lease costs and other information for the period relating to the Company’s operating leases is as follows (in thousands):


	Years Ended December 31,
	2023		2022
Operating lease cost	$	5,277	$	5,300
Short-term lease cost	73		81
Variable lease cost	1,138		730
Total lease cost	$	6,488	$	6,111


	Years Ended December 31,
	2023		2022
Other information:
Operating cash flows net inflows and (outflows) from operating lease	$	(2,922)	$	11,363
ROU assets obtained in exchange for operating lease obligations (including remeasurement of ROU and lease liabilities due to changes in the timing of receipt of lease incentives)	$	(5)	$	231
Weighted-average remaining lease term	7.5 years		8.2 years
Weighted-average discount rate	9.2%		9.1%

Lessee, Operating Lease, Liability, Maturity

Maturities of the Company’s lease liabilities as of December 31, 2023, were as follows (in thousands):



2024	$	7,254
2025	7,478
2026	7,712
2027	5,769
2028	4,855
Thereafter	19,529
Total undiscounted lease payments	52,597
Less imputed interest	(15,028)

Total lease liabilities	$	37,569

Lessor, Operating Lease, Payment to be Received, Maturity

Maturities of the Company’s sublease payments from GeneFab as of December 31, 2023, were as follows (in thousands):


2024	$	4,345
2025	4,476
2026	4,610
2027	4,748
2028	4,891
Thereafter	18,295
Total undiscounted sublease payments	$	41,365

Audit Information	12 Months Ended
Audit Information	Dec. 31, 2023
Audit Information [Abstract]
Auditor Name	KPMG LLP
Auditor Location	San Francisco, CA,
Auditor Firm ID	185

Consolidated Statements of Redeemable Convertible Preferred Stock and Stockholders’ Equity (Deficit) - USD ($)	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit
Beginning balance (in shares) at Dec. 31, 2021	19,517,988
Beginning balance at Dec. 31, 2021	$ 171,833,000
Temporary Equity [Abstract]
Conversion of redeemable convertible preferred stock into common stock in connection with the Reverse Recapitalization, net of transaction cost (in shares)	(19,517,988)
Conversion of redeemable convertible preferred stock into common stock in connection with the Reverse Recapitalization, net of transaction cost	$ (171,833,000)
Ending balance (in shares) at Dec. 31, 2022	0
Ending balance at Dec. 31, 2022	$ 0
Beginning balance (in shares) at Dec. 31, 2021		2,972,409
Beginning balance at Dec. 31, 2021	(111,457,000)	$ 0	$ 3,619,000	$ 0	$ (115,076,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Conversion of redeemable convertible preferred stock into common stock in connection with the Reverse Recapitalization, net of transaction costs (in shares)		19,517,988
Conversion of redeemable convertible preferred stock into common stock in connection with the Reverse Recapitalization, net of transaction cost	171,835,000	$ 2,000	171,833,000
Issuance of common stock upon Reverse Recapitalization, net of transaction costs (in shares)		19,975,963
Issuance of common stock upon Reverse Recapitalization, net of transaction costs	111,959,000	$ 2,000	111,957,000
Contingent earnout liability recognized upon closing of the Reverse Recapitalization	(9,688,000)		(9,688,000)
Cancellation and exchange of convertible note in connection with PIPE financing (in shares)		517,500
Cancellation and exchange of convertible note in connection with PIPE financing	5,184,000		5,184,000
Gain recognized on fair value of embedded derivative on SPAC merger date	(1,289,000)		(1,289,000)
Common Stock Purchase Agreement settled in common stock, net of fees (in shares)		400,000
Common Stock Purchase Agreement settled in common stock, net of fees	924,000		924,000
Exercise of common stock options (in shares)		199,839
Exercise of common stock options	496,000		496,000
Vesting of early exercise of common stock options (in shares)		367,878
Vesting of early exercise of common stock options	965,000		965,000
Issuance of common stock under Employee Stock Purchase Plan (ESPP) (in shares)		110,957
Issuance of common stock under Employee Stock Purchase Plan (ESPP)	151,000		151,000
Stock-based compensation expense	16,392,000		16,392,000
Unrealized gain (loss) on investments	1,000			1,000
Net loss	$ (58,210,000)				(58,210,000)
Ending balance (in shares) at Dec. 31, 2022	44,062,534	44,062,534
Ending balance at Dec. 31, 2022	$ 127,263,000	$ 4,000	300,544,000	1,000	(173,286,000)
Ending balance (in shares) at Dec. 31, 2023	0
Ending balance at Dec. 31, 2023	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common Stock Purchase Agreement settled in common stock, net of fees (in shares)		1,000,000
Common Stock Purchase Agreement settled in common stock, net of fees	528,000	$ 1,000	527,000
Vesting of early exercise of common stock options (in shares)		50,640
Vesting of early exercise of common stock options	136,000		136,000
Issuance of common stock under Employee Stock Purchase Plan (ESPP) (in shares)		586,987
Issuance of common stock under Employee Stock Purchase Plan (ESPP)	375,000		375,000
Stock-based compensation expense	9,670,000		9,670,000
Unrealized gain (loss) on investments	(1,000)			(1,000)
Net loss	$ (71,058,000)				(71,058,000)
Ending balance (in shares) at Dec. 31, 2023	45,700,161	45,700,161
Ending balance at Dec. 31, 2023	$ 66,913,000	$ 5,000	$ 311,252,000	$ 0	$ (244,344,000)

Fair Value Measurements - Narrative (Details)	Dec. 31, 2023	Aug. 07, 2023
GeneFab \| Level 3 \| Discount rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Notes receivable, measurement input	0.1253	0.1372

Stock-Based Compensation

12 Months Ended

Dec. 31, 2023

Share-Based Payment Arrangement [Abstract]

Stock-Based Compensation

2016 Stock Incentive Plan (as Amended and Restated)

The Company’s 2016 Stock Incentive Plan (the “2016 Plan”) provides for the grant of incentive stock options, non-qualified stock options and restricted stock awards to employees, directors, and consultants of the Company.

Stock options granted under the 2016 Plan generally vest over four years and expire no later than ten years after the grant date.

Following the Merger, the 2016 Plan was terminated. No additional stock awards will be granted under the 2016 Plan. All awards previously granted and outstanding as of the effective date of the Merger, were adjusted to reflect the impact of the Merger, but otherwise remain in effect pursuant to their original terms. The shares underlying any award granted under the 2016 Plan that are forfeited back to or repurchased or reacquired by the Company, will revert to and again become available for issuance under the 2022 Plan.

2022 Stock Incentive Plan

On June 8, 2022, upon the Merger, the Company adopted a 2022 Stock Incentive Plan (the “2022 Plan”). The 2022 Plan provides for the grant of incentive stock options to employees, and for the grant of non-statutory stock options, stock appreciation rights, restricted stock awards, restricted stock unit awards, performance awards and other forms of awards to employees, directors and consultants.

The exercise price of an options granted under the 2022 Plan shall not be less than the fair market value of a common stock share on the date of grant. With respect to a 10% stockholder, the exercise price of an option granted shall not be less than 110% of the fair value of the common stock share on the date of grant.

Options granted under the 2022 Plan generally vest over four years and expire no later than ten years after the grant date.

The Company initially reserved 2,492,735 shares of common stock for issuance under the 2022 Plan. On the first day of each year commencing January 1, 2023, the 2022 Plan will automatically increase by 5% of the outstanding number of shares of common stock of the Company on the last day of the preceding calendar year or such lesser number of shares as approved by the Company’s board of directors prior to the effective date of the annual increase. In addition, the shares underlying any award granted under the 2016 Plan that are forfeited back to or repurchased or reacquired by the Company, will revert to and again become available for issuance under the 2022 Plan.

As of December 31, 2023, the total number of shares of common stock available for issuance under the 2022 Plan is 2,419,363.

2022 Inducement Equity Plan

On August 5, 2022, the Company adopted a 2022 Inducement Equity Plan (the “2022 Inducement Plan”). The 2022 Plan provides for the grant of non-statutory stock options, stock appreciation rights, restricted stock awards, restricted stock unit awards, performance awards and other forms of awards to persons not previously an employee of the Company and its affiliates.

The exercise price of an options granted under the 2022 Inducement Plan shall not be less than the fair market value of a common stock share on the date of grant.

Stock options granted under the 2022 Inducement Plan generally vest over four years and expire no later than ten years after the grant date.

The Company initially reserved 2,000,000 shares of common stock for issuance under the 2022 Inducement Plan.

As of December 31, 2023, the total number of shares of common stock available for issuance under the 2022 Inducement Plan is 1,252,913.

2022 Employee Stock Purchase Plan

On June 8, 2022, upon the Merger, the Company adopted a 2022 Employee Stock Purchase Plan (the “ESPP”). The ESPP allows eligible employees to purchase shares of the Company's common stock at a price equal to 85% of the lower of the fair market values of the stock on the first day of an offering or on the date of purchase. The Company’s ESPP operates with rolling offering periods, which are generally 24 months. On November 15, 2023, upon termination of the then-current offering period in accordance with the terms of the ESPP, the Company suspended the ESPP and no new offering periods may commence under the ESPP until such time as later authorized by the Company.

The Company initially reserved 592,584 shares of common stock for issuance under the ESPP. On the first day of each year commencing January 1, 2023, the 2022 Plan will automatically increase by 1% of the outstanding number of shares of common stock of the Company on the last day of the preceding calendar year or such lesser number of shares as approved by the Company’s board of directors prior to the effective date of the annual increase.

As of December 31, 2023, the total number of shares of common stock available for issuance under the ESPP is 336,320.

Stock Options

The following table summarizes the Company’s stock option activity and related information under all equity plans, excluding performance and market awards:


	Number of Options	Weighted-Average Exercise Price		Weighted-Average Remaining Contractual Life (Years)	Aggregate Intrinsic Value (in thousands)
Outstanding at December 31, 2022	4,191,426	$	3.18	9.1	$	6
Granted	2,914,196	$	1.60

Forfeited	(869,943)	$	3.33
Outstanding at December 31, 2023	6,235,679	$	2.42	7.2	$	2
Vested and exercisable at December 31, 2023	2,270,135	$	3.00	6.7	$	2

The weighted-average grant date fair value of options granted during the years ended December 31, 2023 and 2022 were $1.14 and $1.47, respectively. The aggregate intrinsic value of options exercised during the years ended December 31, 2023 and 2022 were $0.0 million and $0.3 million, respectively.

As of December 31, 2023 and 2022, the unrecognized stock-based compensation expense related to stock options was approximately $5.2 million and $8.0 million respectively, expected to be recognized over a weighted-average period of 2.16 years and 2.7 years respectively.

Early Exercise of Stock Options into Restricted Stock

For the years ended December 31, 2023 and 2022, the Company issued zero shares of common stock upon exercise of unvested stock options. As of December 31, 2023 and December 31, 2022, 54,860 and 105,500 shares were held by employees subject to repurchase at an aggregate price of $0.1 million and $0.3 million, respectively.

Performance Awards

In connection with the Merger, on December 19, 2021, Legacy Senti approved 8,400,892 performance awards to existing employees that vest contingent upon the satisfaction of both a four-year service condition and a performance condition tied to the consummation of the Merger. The awards and the associated recognition of stock-based compensation expense were contingent on the Merger being consummated. As of the approval date of the performance awards, Legacy Senti did not have sufficient common stock available for issuance. Upon the Merger, the Company increased the number of shares authorized and 6,796,074 awards were granted on June 8, 2022.


	Number of Options	Weighted-Average Exercise Price		Weighted-Average Remaining Contractual Life (Years)	Aggregate Intrinsic Value (in thousands)
Outstanding at December 31, 2022	5,368,501	$	9.92	9.0	$	—
Granted	—	$	—

Forfeited	(336,990)	$	9.92
Outstanding at December 31, 2023	5,031,511	$	9.92	7.5	$	—
Vested and exercisable at December 31, 2023	2,009,756	$	9.92	7.3	$	—

There were no performance based options granted or exercised during the year ended December 31, 2023, and there were 6,796,074 performance based options granted and no performance based options exercised during the year ended December 31, 2022.

As of December 31, 2023, the unrecognized stock-based compensation expense related to performance awards was approximately $3.6 million, expected to be recognized over a weighted-average period of 1.52 years.

Market Awards

In connection with the Merger, on December 19, 2021, Legacy Senti approved 605,451 market award options to its co-founder and Chief Executive Officer, Dr. Timothy Lu, that vest contingent upon the satisfaction of all three of the following conditions: a service condition, a performance condition tied to the consummation of the Merger, and market conditions. The market condition is achieved in four tranches, where 25% of the options will vest when the trading price of the Company’s stock is above various thresholds of price per share. The award and the associated recognition of stock-based compensation were contingent on the Merger being consummated. The estimated fair value of the market awards at the grant date was based on a Monte Carlo simulation valuation model. As of the approval date, Legacy Senti did not have sufficient common stock available for issuance to allow for exercise of the stock options. Upon the Merger, the Company increased the number of shares authorized and 315,748 awards were granted on June 8, 2022. Through December 31, 2023, these market awards did not meet the vesting thresholds.

The were no market based options granted or exercised during the year ended December 31, 2023, and there were 315,748 market based options granted and no market based options exercised during the year ended December 31, 2022.

As of December 31, 2023, the unrecognized stock-based compensation expense related to market awards was approximately $0.2 million, expected to be recognized over a weighted-average period of 0.63 years.

Restricted Stock Units

The following table summarizes the Company’s restricted stock units activity and related information under all equity plans:


	Number of Restricted Stock Units	Weighted-Average Grant Date Fair Value
Outstanding at December 31, 2022	447,948	$	2.50


Forfeited	(222,666)	$	—
Outstanding at December 31, 2023	225,282	$	2.50

As of December 31, 2023, the unrecognized stock-based compensation expense related to restricted stock units was approximately $0.2 million, expected to be recognized over a weighted-average period of 0.72 years.

Stock-Based Compensation Expense

The Company estimates the fair value of stock options using a Black-Scholes option-pricing model. The fair value of restricted stock is based on the fair value of the Company’s common stock on the grant date.

The Company uses the assumptions below for the Black-Scholes option pricing model, which are subjective and generally require significant judgment.

Fair Value of Common Stock — The fair value of the shares of common stock has historically been determined by the Company’s board of directors as there was no public market for the common stock. The board of directors determined the fair value of the common stock by considering a number of objective and subjective factors, including: third-party valuations of the Company’s common stock, the valuation of comparable companies, the Company’s operating and financial performance, and general and industry-specific economic outlook, amongst other factors. As of the closing of the Merger and going forward, the fair value of common stock will be based on the publicly traded market value.

Expected Term — The expected term represents the period that the Company’s stock options are expected to be outstanding and is determined using the simplified method (based on the mid-point between the vesting date and the end of the contractual term). The expected term for the ESPP purchase rights is the length of the purchase period.

Volatility — The expected volatility is based on the average historical volatility of comparable publicly-traded peer companies, over a period equal to the expected term of the stock option grants, as the Company was not publicly traded prior to the Merger and does not have a trading history for its common stock for a sufficient period of time subsequent to the Merger.

Risk-free Rate — The risk-free rate assumption is based on the U.S. Treasury zero-coupon issues in effect at the time of grant for periods corresponding with the expected term of the option.

Dividends — The Company has never paid dividends on its common stock and does not anticipate paying dividends on common stock. Therefore, the Company uses an expected dividend yield of zero.

The assumptions used to determine the grant date fair value of non-market based, stock options granted were as follows, presented on a weighted-average basis:


	Years Ended December 31,
	2023	2022
Expected term (in years)	5.9	5.8
Expected volatility	82.6%	78.8%
Risk-free interest rate	3.6%	3.2%
Dividend yield	—	—

Total stock-based compensation expense was as follows (in thousands):


	Years Ended December 31,
	2023		2022
General and administrative	$	10,236	$	13,340
Research and development	1,456		2,222
Total stock-based compensation expense	$	11,692	$	15,562

In August 2023, in connection with the GeneFab transaction, the Company’s board of directors approved the modification of equity awards as part of termination of employment for the Company's employees transferred to GeneFab, including the Company’s Chief Technology Officer. The award modifications included the acceleration of certain non-vested stock options and the extension of the post-termination exercise period of certain vested stock options. The Company accounted for the award modifications under ASC 718, Compensation – Stock Compensation. During year ended December 31, 2023, the Company recorded a one-time, noncash incremental compensation expense net of the required reversal of previously recognized compensation attributed to non-vested awards in the amount of $2.0 million related to the equity awards modifications of the employees that were extended offers of employment by GeneFab which was included in net income from discontinued operations in the consolidated statements of operations and comprehensive loss.

Total stock-based compensation expense from discontinued operations was $(2.0) million and $0.8 million for the years ended December 31, 2023 and 2022, respectively.

Related Parties (Details) $ / shares in Units, $ in Thousands			1 Months Ended	12 Months Ended
	Jun. 08, 2022 $ / shares shares	May 21, 2021 USD ($)	Jan. 31, 2023 USD ($)	Dec. 31, 2023 USD ($) board_seat shares	Dec. 31, 2022 USD ($) board_seat shares	Aug. 07, 2023 USD ($)	May 19, 2022 USD ($)
Related Party Transaction [Line Items]
Common stock, shares issued (in shares) \| shares				45,700,161	44,062,534
Number of seats on the board of directors \| board_seat				6	7
Sublease income				$ 2,323	$ 0
Research and development expense				32,150	28,145
Related Party
Related Party Transaction [Line Items]
Accounts receivable				17,592	0
Research and development expense				$ 3,113	$ 0
May 2022 Note
Related Party Transaction [Line Items]
Principal amount of unsecured convertible promissory note							$ 5,200
Common Class A
Related Party Transaction [Line Items]
Conversion of redeemable convertible preferred stock into common stock in connection with the Reverse Recapitalization, net of transaction costs (in shares) \| shares	517,500
Common stock share price (in dollars per share) \| $ / shares	$ 10.00
NEA
Related Party Transaction [Line Items]
Common stock, shares issued (in shares) \| shares				4,426,151	4,426,151
Number of seats on the board of directors \| board_seat				1	1
BlueRock \| Collaborative Arrangement, Transaction with Party to Collaborative Arrangement
Related Party Transaction [Line Items]
Expected costs and expenses incurred		$ 10,000
Term of agreement (in years)		3 years
Bayer
Related Party Transaction [Line Items]
Common stock, shares issued (in shares) \| shares				5,878,488	5,878,488
Seer, Inc. \| Lab Automation Equipment Purchase \| Related Party
Related Party Transaction [Line Items]
Related party transaction, amount of transaction			$ 200
Expenses incurred from transaction, payment term (in years)			2 years
GeneFab
Related Party Transaction [Line Items]
Prepayments for manufacturing and research activities						$ 18,900
GeneFab \| Alameda
Related Party Transaction [Line Items]
Sublease income				$ 2,000
GeneFab \| Related Party
Related Party Transaction [Line Items]
Prepayments for manufacturing and research activities				14,800		$ 18,900
Research and development expense				3,100
GeneFab \| Related Party \| Alameda
Related Party Transaction [Line Items]
Sublease income				2,300
GeneFab \| Sublease Rent \| Related Party \| Alameda
Related Party Transaction [Line Items]
Accounts receivable				1,500
GeneFab \| Costs Incurred On Behalf Of GeneFab \| Related Party
Related Party Transaction [Line Items]
Accounts receivable				$ 1,400

Revenue - Entity-wide information (Details) - Revenue Benchmark - Customer Concentration Risk	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Customer A
Concentration Risk [Line Items]
Percentage of concentration	77.00%	77.00%
Customer B
Concentration Risk [Line Items]
Percentage of concentration	23.00%	23.00%

Stockholders’ Equity (Deficit) - Assumptions used in valuation of contingent earnout shares (Details)	Dec. 31, 2023 $ / shares year	Dec. 31, 2022 $ / shares year
Current stock price
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input \| $ / shares	0.66	1.41
Expected share price volatility
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input	1.135	0.850
Risk-free interest rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input	0.0451	0.0432
Estimated dividend yield
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input	0.000	0.000
Expected term (years)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input \| year	1.5	2.4

Organization and Description of Business	12 Months Ended
Organization and Description of Business	Dec. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Description of Business	Organization and Description of Business Senti Biosciences, Inc. and its subsidiaries (the “Company” or “Senti”), is an early clinical stage biotechnology company developing next-generation cell and gene therapies engineered with its gene circuit platform technologies for patients living with incurable diseases. Senti’s mission is to create a new generation of smarter therapies that can outsmart complex diseases using novel and unprecedented approaches. Senti has built a synthetic biology platform that enables it to program next-generation cell and gene therapies with gene circuits. These gene circuits, which are created from novel and proprietary combinations of DNA sequences, reprogram cells with biological logic to sense inputs, compute decisions and respond to their cellular environments. The Company is headquartered in South San Francisco, California. On June 8, 2022 (the “Closing Date”), Dynamics Special Purpose Acquisition Corp. (“Dynamics” or “DYNS”) consummated a merger pursuant to which Explore Merger Sub, Inc. (“Merger Sub”), a Delaware corporation and wholly owned subsidiary of Dynamics, merged with and into Senti Sub I, Inc., formerly named Senti Biosciences, Inc. (“Legacy Senti”), with Legacy Senti surviving as a wholly-owned subsidiary of Dynamics (such transactions, the “Merger,” and, collectively with the other transactions described in the merger agreement (as defined below, the “Reverse Recapitalization”)). As a result of the Merger, Dynamics was renamed Senti Biosciences, Inc. Refer to Note 3. Reverse Recapitalization, for further details of the Merger. On August 7, 2023, the Company completed a transaction with GeneFab, LLC (“GeneFab”), a contract manufacturing and synthetic biology biofoundry focused on next-generation cell and gene therapies. As part of that transaction, the Company disposed of its non-oncology business and in-house manufacturing services and subleased its manufacturing facility to GeneFab. Refer to Note 4. GeneFab Transaction, for further details of the transaction, and to Note 16. Related Parties, for related party discussion. Liquidity and Going Concern These consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (GAAP) assuming the Company will continue as a going concern. The going concern assumption contemplates the realization of assets and satisfaction of liabilities in the normal course of business. The consolidated financial statements do not include any adjustments to the carrying amounts and classification of assets, liabilities, and reported expenses that may be necessary if the Company were unable to continue as a going concern. The Company has devoted substantially all of its efforts to organizing and staffing, business planning, raising capital, and conducting preclinical studies and has not realized substantial revenues from its planned principal operations. To date, the Company raised aggregate gross proceeds of $300.1 million from the Merger and PIPE Financing, the issuance of shares of our common stock, the issuance of shares of our redeemable convertible preferred stock, the issuance of convertible notes and, to a lesser extent, through collaboration agreements and governmental grants. At December 31, 2023 and December 31, 2022, the Company had an accumulated deficit of $244.3 million and $173.3 million, respectively. The Company’s net losses were $71.1 million and $58.2 million for the years ended December 31, 2023 and 2022, respectively. Substantially all of the Company’s net losses resulted from costs incurred in connection with the Company’s research and development programs, from general and administrative costs associated with the Company’s operations, and impairment of the Company’s long-lived assets. The Company expects to incur substantial operating losses and negative cash flows from operations for the foreseeable future as the Company advances its preclinical activities and clinical trials for its product candidates in development. As of December 31, 2023 and 2022, the Company had cash, cash equivalents, and short-term investments of $35.9 million and $98.6 million. As of March 21, 2024, the issuance date of the consolidated financial statements as of and for the year ended December 31, 2023, there is uncertainty about whether the Company’s combined cash, cash equivalents, and short-term investments will be sufficient to fund operations, including clinical trial expenses and capital expenditure requirements, beyond twelve months from the issuance date of these financial statements and therefore the Company concluded that substantial doubt existed about the Company’s ability to continue as a going concern. The transaction with GeneFab provided the Company with additional capital in the form of a note receivable and rights to future manufacturing and research activities and reduced longer-term operating expenses. Refer to Note 4. GeneFab Transaction, for further details of the GeneFab transaction. The Company’s continued existence is dependent upon management’s ability to raise capital and develop profitable operations. Management is devoting substantially all of its efforts to developing its business and raising capital and there can be no assurance that the Company’s efforts will be successful. No assurance can be given that management’s actions will result in profitable operations or the meeting of ongoing liquidity needs. NASDAQ Bid Price Compliance Notice On August 7, 2023, the Company received written notice from the Listing Qualifications Department of The Nasdaq Stock Market LLC (“Listing Qualifications Department”) notifying the Company that, for the last 30 consecutive trading days, the closing bid price of the Company’s common stock had closed below the minimum bid price requirement of $1.00 per share for continued listing on The Nasdaq Global Market. The Company had been provided an initial compliance period of 180 calendar days, or until February 5, 2024, to regain compliance with the minimum bid price requirement. Issuers listed on The Nasdaq Global Market are not eligible for a second 180-day grace period under the Nasdaq Listing Rules. However, based upon the Company’s compliance with the various criteria required under Nasdaq Listing Rule 5810(c)(3)(A)(ii) to obtain a second 180-day grace period applicable to issuers listed on The Nasdaq Capital Market, the Company applied to transfer the listing of its Common Stock to The Nasdaq Capital Market.

Other Financial Statement information - Schedule of Property and Equipment, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Property, Plant and Equipment [Line Items]
Property and equipment at cost	$ 31,520	$ 54,316
Less: accumulated depreciation	(6,182)	(2,955)
Property and equipment, net	25,338	51,361
Lab equipment
Property, Plant and Equipment [Line Items]
Property and equipment at cost	8,186	7,855
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment at cost	22,648	1,869
Computer equipment and software
Property, Plant and Equipment [Line Items]
Property and equipment at cost	360	374
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property and equipment at cost	326	326
Construction in progress
Property, Plant and Equipment [Line Items]
Property and equipment at cost	$ 0	$ 43,892

Operating Leases - Total Lease Cost (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Leases [Abstract]
Operating lease cost	$ 5,277	$ 5,300
Short-term lease cost	73	81
Variable lease cost	1,138	730
Total lease cost	$ 6,488	$ 6,111

Net Loss Per Share (Tables)

12 Months Ended

Dec. 31, 2023

Earnings Per Share [Abstract]

Schedule of Earnings Per Share, Basic and Diluted

A reconciliation of net loss available to common stockholders and the number of shares in the calculation of basic and diluted loss per share is as follows (in thousands, except share and per share amounts):


	Years Ended December 31,
	2023		2022
Net loss from continuing operations	$	(83,406)	$	(49,665)
Net income (loss) from discontinued operations	12,348		(8,545)
Net loss	$	(71,058)	$	(58,210)

Weighted-average shares used in computing net loss per share, basic and diluted	44,372,223		26,110,785

Net loss per share from continuing operations, basic and diluted	$	(1.88)	(1.90)
Net income (loss) per share from discontinued operations, basic and diluted	0.28		(0.33)
Net loss per share attributable to common stockholders, basic and diluted	$	(1.60)	$	(2.23)

Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share

The following potential common stock securities were excluded from the computation of diluted net loss per share attributable to common stockholders for the periods presented because including them would have been anti-dilutive (on an as-converted basis):


	Years Ended December 31,
	2023	2022

Stock options to purchase common stock	11,582,938	9,875,675
Unvested early exercised options	54,860	105,500
Restricted stock units outstanding	225,282	447,948
Contingent earnout common stock	2,000,000	2,000,000
GeneFab Option	19,633,444	0
Total	33,496,524	12,429,123

Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2023

Accounting Policies [Abstract]

Reconciliation Of Cash And Cash Equivalents And Restricted Cash

The following table provides a reconciliation of cash and cash equivalents and restricted cash reported within the consolidated balance sheets that total to the amounts shown in the consolidated statements of cash flows for the Company:


	December 31,
	2023		2022

Cash and cash equivalents	$	35,926	$	57,621
Restricted cash	3,522		3,366
Total	$	39,448	$	60,987

Restrictions on Cash and Cash Equivalents


	December 31,
	2023		2022

Cash and cash equivalents	$	35,926	$	57,621
Restricted cash	3,522		3,366
Total	$	39,448	$	60,987

Schedule of Property and Equipment, Net

Property and equipment, net is stated at cost, net of accumulated depreciation. Depreciation is calculated using the straight-line method over the estimated useful lives of the assets, which are as follows:


Asset Classification						Estimated useful Life
Small equipment						2 years
Computer equipment and software						3 years
Laboratory equipment						5-7 years
Furniture and fixtures						5-7 years
Leasehold improvements						Shorter of the lease term and the useful life

Property and equipment, net consisted of the following (in thousands):


	December 31,

	2023		2022
Lab equipment	$	8,186	$	7,855
Leasehold improvements	22,648		1,869
Computer equipment and software	360		374
Furniture and fixtures	326		326
Construction in progress	—		43,892
Property and equipment at cost	31,520		54,316
Less: accumulated depreciation	(6,182)		(2,955)
Property and equipment, net	$	25,338	$	51,361

GeneFab Transaction - Narrative (Details) $ / shares in Units, $ in Thousands		12 Months Ended
	Aug. 07, 2023 USD ($) employee $ / shares shares	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)
Level 3
Related Party Transaction [Line Items]
Consideration	$ 37,300
GeneFab
Related Party Transaction [Line Items]
Consideration received in collaborative development agreement	37,800
Upfront payment under research collaboration and license agreement	18,900
Variable consideration	18,900
Notes receivable at fair value	16,600
Prepayments for manufacturing and research activities	$ 18,900
Employment offer, number of employees \| employee	45
Option, maximum purchase amount (in shares) \| shares	19,633,444
Option, maximum worth	$ 20,000
Option, exercise price (in dollars per share) \| $ / shares	$ 1.01867
Option, installments, percentage of stock outstanding (in percent)	19.90%
Revenue, remaining performance obligation, variable consideration, percentage of realized gains	10.00%
GeneFab \| Discontinued Operations, Disposed of by Sale \| Non-Oncology Business
Related Party Transaction [Line Items]
Gain on disposal of business		$ 21,861	$ 0
Assets sold		5,500
GeneFab \| Contingent Consideration Receivable \| Level 3
Related Party Transaction [Line Items]
Fair value of asset	$ 1,800	1,816
GeneFab \| Equity Option
Related Party Transaction [Line Items]
Derivative liability		$ (9,600)

Income Tax - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Deferred tax assets:
Net operating losses	$ 33,566	$ 25,249
Capitalized R&D Section 174 expense	10,146	5,131
Tax credits	9,237	6,053
Lease liability	6,005	7,789
Stock-based compensation	4,785	683
Accruals and reserves	724	756
Related Party Fair Value Adjustment	346	0
Fixed asset basis	0	259
Total deferred tax assets	64,809	45,920
Deferred tax liabilities:
Operating lease right-of-use assets	(1,548)	(3,869)
Fixed asset basis	(2,008)	0
Total deferred tax liabilities	(3,556)	(3,869)
Valuation allowance	(61,253)	(42,051)
Net deferred taxes	$ 0	$ 0

Related Parties

12 Months Ended

Dec. 31, 2023

Related Parties

GeneFab Transaction

On August 7, 2023, the Company entered into a framework agreement with GeneFab and Valere Bio, Inc., a Delaware corporation and the parent company of GeneFab, which is wholly owned by Celadon Partners, LLC, pursuant to which the Company, subject to the terms and conditions therein, sold, assigned and transferred its rights, title and interest in certain of the assets and contractual rights, including all of the Company’s equipment at the Company’s facilities in Alameda and certain of the Company’s non-oncology license, intellectual property related to the schematics for and design of the Alameda facility, and subleased to GeneFab its premises under the lease for the Alameda facility. The transaction will provide the Company with additional capital in the form of a note receivable and rights to future manufacturing and research activities performed by GeneFab at market rates and reduced longer term operating expenses.

Concurrently with the transaction, the Company and GeneFab entered into a development and manufacturing services agreement (the “Services Agreement”), pursuant to which GeneFab will provide certain services to the Company using the subleased Alameda facility and acquired equipment. As part of this transaction, the Company entered into a transition services agreement (“Transition Services Agreement”) with GeneFab whereby certain

services are to be provided by each party to the other party during a transition period beginning on the closing of the transaction.

Under the terms of the transaction, the Company is entitled to receive total consideration of $37.8 million before the end of 2025, of which $18.9 million was due at closing and was netted against prepayment due to GeneFab for future manufacturing and research activities. The remaining $18.9 million will be paid to the Company in installments in 2024 and 2025 (the “GeneFab Note Receivable”), subject to satisfaction of certain conditions. The Company elected to account for the GeneFab Note Receivable under the fair value option and recorded the GeneFab Note Receivable at its fair value of $16.6 million at the closing date of the transaction. The GeneFab Note Receivable will be remeasured each reporting period with changes from remeasurement included in other income (expense) in the consolidated statements of operations and comprehensive loss. Refer to Note 5. Fair Value Measurements.

The Company is entitled to $18.9 million in future manufacturing and research activities to be rendered under the services agreement, which are recorded in GeneFab prepaid expenses on the consolidated balance sheet. The Company determined that the $18.9 million for future manufacturing and research activities, inclusive of the volume discount provided, was executed at market terms and does not result in any impact to the total consideration received from GeneFab for the disposal of the business.

As part of the transaction, the Company subleased the facility in Alameda, California to GeneFab which will support the clinical manufacturing of the Company’s chimeric antigen receptor natural killer (CAR-NK) programs, including SENTI-202. Refer to Note 7. Operating Leases for additional information on the sublease.

The Company agreed to grant a license to GeneFab under certain of its intellectual property rights to conduct manufacturing services and to research, develop, manufacture and commercialize products outside of oncology, pursuant to a license agreement under negotiation (the “Non-Oncology License”).

In connection with the transaction, Philip Lee, Ph.D., Co-Founder and former Chief Technology Officer of the Company, assumed the role of Chief Executive Officer of GeneFab. Additionally, GeneFab extended offers of employment to 45 of the Company's employees formerly employed in its research and development and manufacturing functions. All 45 employees accepted the offers of employment and are actively engaged in providing manufacturing and research activities to the Company.

GeneFab was granted an option to purchase up to 19,633,444 shares (i.e. up to $20.0 million worth) of the Company’s common stock at a purchase price of $1.01867 (the “GeneFab Option”). The GeneFab Option becomes exercisable upon the execution of the license agreement, no later than August 7, 2026. The GeneFab Option may be exercised in installments of common stock equal to no more than 19.9% of the Company’s outstanding shares of common stock as of the closing date of the transaction. The purchase of the remaining shares under the GeneFab Option require stockholder approval. The Company determined that the GeneFab Option was a derivative as the terms of the instrument contain certain provisions that preclude equity classification in accordance with ASC 815. As such, the GeneFab Option was recorded as a liability at its fair value of $9.6 million at the closing date of the transaction and subsequently remeasured with changes in fair value recorded in other income (expense) in the consolidated statements of operations and comprehensive loss. Refer to Note 5. Fair Value Measurements.

As additional consideration for the transaction, the Company and GeneFab entered into a seller economic share agreement (the “GeneFab Economic Share”), pursuant to which the Company will be entitled to receive ten percent of the realized gains of GeneFab’s parent company arising and resulting from any cash or in-kind distributions from GeneFab in connection with a dividend or sale event, subject to the terms and conditions of the GeneFab Economic Share. The Company elected to account for the GeneFab Economic Share under the fair value option and recorded the GeneFab Economic Share at its fair value of $1.8 million at the date of the transaction. The GeneFab Economic Share is remeasured each reporting period with changes from remeasurement included in other income (expense) in the consolidated statements of operations and comprehensive loss. Refer to Note 5. Fair Value Measurements.

The Company determined that GeneFab is a variable interest entity (VIE) since its total equity at risk is not sufficient to finance its activities without additional subordinated financial support. The Company performed a qualitative analysis to determine if it is the primary beneficiary of GeneFab and determined it does not have the

power to direct the significant activities of GeneFab. As a result, the Company determined it is not the primary beneficiary and therefore does not consolidate GeneFab.

Refer to Note 16. Related Parties for GeneFab related party considerations.

Gain on the Disposal of Business

As the assets and contractual rights transferred to GeneFab were determined to constitute a business as defined in ASC 805, Business Combinations, the Company accounted for the disposal by applying the derecognition guidance in ASC 810, Consolidation, which requires that a gain or loss be recognized for the difference between the carrying value of the assets sold and the fair value of the consideration received (or receivable).

As of August 7, 2023, the total fair value of the consideration was determined to be $37.3 million, including the GeneFab prepaid expenses of $18.9 million, the estimated fair value of the GeneFab Note Receivable of $16.6 million and the estimated fair value of the GeneFab Economic Share of $1.8 million. Out of the total consideration, $9.6 million was allocated to the GeneFab Option, representing its estimated fair value as of the closing date.

In connection with the sale, the Company recognized a gain on disposal in the amount of $21.9 million in net income from discontinued operations during the year ended December 31, 2023, representing the excess of the fair value of the consideration (net of the portion allocated to the GeneFab Option) over the carrying value of the assets sold of $5.5 million. The gain on disposal was primarily related to the transfer of the non-oncology intellectual property to GeneFab which had no carrying value.

Discontinued Operations

In accordance with ASC 205, Presentation of Financial Statements, the Company determined that the sale of the non-oncology business, including the equipment and transfer of in-house manufacturing activities in the Alameda facility, to GeneFab represented a strategic shift that will have a major effect on the Company’s operations and financial results, thus meeting the criteria to be reported as discontinued operations. Discontinued operations include the cost and depreciation of equipment and related deposits or liabilities, manufacturing personnel-related costs including costs arising as a result of the disposal such as equity award modifications and severance, and the gain from the disposal of the business. Refer to Note 9. Stockholders’ Equity (Deficit), for further details of the award modifications.

The following table summarizes the major classes of assets and liabilities of the discontinued operations (in thousands):


	December 31,
	2023		2022
Prepaid expenses and other current assets	$	—	$	209
Total current assets of discontinued operations	$	—	$	209

Property and equipment, net	$	—	$	4,775
Other long-term assets	—		10
Total non-current assets of discontinued operations	$	—	$	4,785

Accounts payable	$	—	$	897
Accrued expenses and other current liabilities	243		288
Total current liabilities of discontinued operations	$	243	$	1,185

The following table summarizes the operating results of the discontinued operations (in thousands):


	Years Ended December 31,
	2023		2022
Operating expenses:
Research and development	$	10,003	$	5,922
General and administrative	(496)		2,623
Total operating expenses	9,507		8,545
Loss from discontinued operations	(9,507)		(8,545)
Other income (expense)	(6)		—
Gain on disposal of business	21,861		—
Net income (loss) from discontinued operations	$	12,348	$	(8,545)

General and administrative expenses were negative for the year ended December 31, 2023 due to the reversal of compensation expense for unvested awards that were cancelled due to the termination of employees subsequently hired by GeneFab. See Note 9. Stockholders’ Equity (Deficit).

The following table summarizes the cash flow information of the discontinued operations (in thousands):


	Years Ended December 31,
	2023		2022
Operating activities (noncash adjustments to net income):
Depreciation	$	185	$	31
Stock-based compensation expense	(2,022)		830
Gain on disposal of business	21,861		—
Investing activities: (1)
Purchases of property and equipment	(4,079)		(1,670)
Supplemental disclosures of noncash investing items:
Purchases of property and equipment in accounts payable and accrued expenses	—		3,135

________________

(1) The total consideration received of $37.8 million is a non-cash investing activity.

Related Parties

NEA

NEA held 4,426,151 shares of common stock as of December 31, 2023 and 2022. NEA held one of the six seats and one of the seven seats on the Company’s board of directors as of December 31, 2023 and 2022, respectively.

Bayer Healthcare LLC

On May 19, 2022, Legacy Senti issued to Bayer a $5.2 million unsecured convertible promissory note. On June 8, 2022, the May 2022 Note was automatically cancelled and exchanged for 517,500 shares of Class A Common Stock at a price of $10.00 per share. Refer to Note 8. Convertible Note, for further details of the convertible note.

On May 21, 2021, the Company entered into a collaboration and option agreement (“BlueRock Agreement”) with BlueRock, a wholly-owned subsidiary of Bayer, pursuant to which the Company granted to BlueRock an option (“BlueRock Option”), on a collaboration program-by-collaboration program basis, to obtain an exclusive or non-exclusive license to develop, manufacture and commercialize cell therapy products that contain cells of specified types and which incorporate an option gene circuit from such collaboration program or a closely related derivative gene circuit. The Company is responsible for up to $10 million in costs and expenses incurred in

connection with the research plan and related activities to be conducted over a term of three years as specified in the collaboration and option agreement. If the Company and BlueRock agree to add new research activities to the research plan, then BlueRock will be obligated to reimburse the Company for the costs and expenses incurred that, together with costs and expenses incurred under the initial research plan, exceed $10 million.

The Company concluded that the Agreement is not within the scope of ASC 808, Collaborative Arrangements, because the Company did not receive any consideration and therefore, is not exposed to both significant risks and rewards for the arrangement. The Company also determined that the agreement is also not currently within the scope of ASC 606 because the BlueRock Agreement does not currently meet the criteria of a contract with a customer, and will not be within the scope of ASC 606 until any consideration is paid. Potential future milestone payments and royalties are subject to BlueRock’s exercise of the BlueRock Option and execution of a commercial license agreement by both parties. Under the BlueRock Agreement, the specific financial terms for milestone payments and royalties will be negotiated and agreed to only after the option is exercised.

Bayer held 5,878,488 shares of the Company’s common stock as of December 31, 2023 and 2022. Accordingly, Bayer is considered a related party.

Seer, Inc.

In January 2023, the Company acquired lab automation equipment purchased from Seer, Inc. (“Seer”) (NASDAQ: SEER). Omid Farokhzad, a member of the Company’s board of directors is the Chief Executive Officer for Seer. The consideration of $0.2 million, plus interest, will be paid over a two-year period, and title will transfer to the Company upon final payment. The transaction was classified as a finance lease in accordance with ASC 842.

GeneFab, LLC.

As a result of the transaction with GeneFab (refer to Note 4. GeneFab Transaction), the Company received the GeneFab Note Receivable and the GeneFab Economic Share and provided GeneFab with the GeneFab Option. Refer to Note 5. Fair Value Measurements.

The Company also subleased its manufacturing facility in Alameda to GeneFab and recorded sublease income of $2.3 million including variable costs charged for the year ended December 31, 2023. As of December 31, 2023, the Company had $1.5 million of charges related to the Transition Services Agreement, sublease rent and other charges due from GeneFab which are included in GeneFab receivable on the consolidated balance sheet.

In connection with the services agreement entered into with GeneFab, the Company is entitled to $18.9 million for future services under the agreement, of which $14.8 million remained in GeneFab prepaid expenses as of December 31, 2023. Additionally, amounts due from GeneFab related to costs incurred by the Company on its behalf were $1.4 million as of December 31, 2023 and were recorded in GeneFab receivable on the consolidated balance sheet. The Company incurred $3.1 million of research and development expenses under the services agreement during the year ended December 31, 2023.

Based on the intricacies of the GeneFab Transaction noted above and in Note 4. GeneFab Transaction, we have determined that GeneFab is a related party.

- Definition

The entire disclosure for related party transactions. Examples of related party transactions include transactions between (a) a parent company and its subsidiary; (b) subsidiaries of a common parent; (c) and entity and its principal owners; and (d) affiliates.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480990/946-20-50-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
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-Name Accounting Standards Codification
-Section 50
-Paragraph 5
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-URI https://asc.fasb.org//1943274/2147480990/946-20-50-5

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480990/946-20-50-6

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 235
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481062/946-235-50-2

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 235
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481062/946-235-50-2

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 850
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-Paragraph 1
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-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483326/850-10-50-1

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-07(2)(g)(3))
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-URI https://asc.fasb.org//1943274/2147483575/946-220-S99-1

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
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-Name Accounting Standards Codification
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-Paragraph 1
-Subparagraph (SX 210.6-07(2)(c))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483575/946-220-S99-1

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-07(2)(e))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483575/946-220-S99-1

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 850
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org//850/tableOfContent

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 850
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483326/850-10-50-6

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 850
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483326/850-10-50-1

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 850
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483326/850-10-50-1

+ Details

Income Tax - Net Operating Losses And Tax Credit Carryforwards (Details) $ in Thousands	Dec. 31, 2023 USD ($)
Federal
Operating Loss Carryforwards And Tax Credit Carryforwards [Line Items]
Tax credits	$ 6,670
Federal \| Post December 31, 2017
Operating Loss Carryforwards And Tax Credit Carryforwards [Line Items]
Net operating losses	132,504
Federal \| Pre January 1, 2018
Operating Loss Carryforwards And Tax Credit Carryforwards [Line Items]
Net operating losses	3,508
State
Operating Loss Carryforwards And Tax Credit Carryforwards [Line Items]
Net operating losses	71,637
Tax credits	$ 5,605

Summary of Significant Accounting Policies

12 Months Ended

Dec. 31, 2023

Accounting Policies [Abstract]

Summary of Significant Accounting Policies

Basis of Presentation

The accompanying consolidated financial statements have been prepared in conformity with generally accepted accounting principles in the United States of America (“U.S. GAAP”) and the rules and regulations of the Securities and Exchange Commission (“SEC”). Any reference in these notes to applicable guidance is meant to refer to the authoritative U.S. GAAP as found in the Accounting Standards Codification (“ASC”) and as amended by Accounting Standards Updates (“ASU”) of the Financial Accounting Standards Board (“FASB”). The consolidated financial statements include the accounts of Senti Biosciences, Inc., and its wholly-owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation. The Company has one business activity and operates in one reportable segment within continuing operations.

Unless otherwise noted, the Company has retroactively adjusted all common and preferred share and related price information to give effect to the exchange ratio established in the Merger Agreement.

The Company determined that the assets sold to GeneFab met the criteria for presentation as a discontinued operation. As a result, the Company has retrospectively restated its consolidated balance sheet at December 31, 2022 and consolidated statements of operations and comprehensive loss for the year ended December 31, 2022 to reflect the assets and liabilities and operating results, respectively, related to the disposed business in discontinued operations. The Company has chosen not to segregate the cash flows of the disposed business in the consolidated statements of cash flows. Supplemental disclosures related to discontinued operations for the statements of cash flows have been provided in Note 4. GeneFab Transaction. Unless otherwise specified, the disclosures in these consolidated financial statements refer to continuing operations only.

Use of Estimates

The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Significant estimates and assumptions reflected in these consolidated financial statements include, but are not limited to, the valuation of stock-based awards, the accrual for research and development expenses, the valuation of contingent earnout, the valuation of GeneFab Option, the valuation of GeneFab Economic Share, the valuation of the GeneFab Note Receivable, the discount rate used to discount future cash flows for the impairment of long-lived assets, and the determination of the incremental borrowing rate. The Company evaluates its estimates and assumptions on an ongoing basis using historical experience and other factors and adjusts those estimates and assumptions when facts and circumstances dictate. Actual results could differ from those estimates.

Concentration of Credit Risk

Financial instruments that potentially subject the Company to a significant concentration of credit risk consist of cash, cash equivalents, and short-term investments that are maintained in checking and money market accounts at one financial institution, which at times, may exceed federally insured limits. The Company’s short-term investments, if any, are limited to certain types of debt securities issued by the U.S. government, its agencies, and institutions with investment-grade credit ratings, and places restrictions on maturities and concentration by type and issuer. As of December 31, 2023 and 2022, the Company has not experienced any credit losses in such accounts or investments.

As of December 31, 2023, the Company has prepaid future manufacturing and research services of $14.8 million under the development and manufacturing services agreement entered into with GeneFab, a related party. The Company also has a receivable from GeneFab under the framework agreement with a fair value of $17.2 million, subject to satisfaction of certain conditions. The prepaid expense and receivable balances from GeneFab potentially subject the Company to a significant concentration of credit risk if the Company is unable to realize these balances. Refer to Note 4. GeneFab Transaction, for further details of the GeneFab transaction.

Cash, Cash Equivalents, and Restricted Cash

Cash equivalents consist of amounts deposited in money market funds and securities with original maturity dates of three months or less, which are stated at fair value.

The Company’s restricted cash consists of cash deposited with a financial institution as collateral for a letter of credit required under the Company’s headquarters and research facility leases as well as employee contributions collected under employee stock purchase plan. The restricted cash is presented separately from cash and cash equivalents and classified as non-current on the consolidated balance sheets, as the Company expects the cash to remain restricted for a period greater than one year.


	December 31,
	2023		2022

Cash and cash equivalents	$	35,926	$	57,621
Restricted cash	3,522		3,366
Total	$	39,448	$	60,987

Short-term Investments

Investments in marketable securities with original maturities less than 12 months from the balance sheet date, if any, are classified as short-term investments. Investments with original maturities of greater than 12 months from

the balance sheet date, if any, are classified as long-term. The Company classifies all of its investments as available-for-sale and records such assets at estimated fair value in the consolidated balance sheets, with unrealized gains and losses, if any, reported as a component of other comprehensive loss within the consolidated statement of operations and comprehensive loss, and as a separate component of stockholders’ equity. These investments consist of corporate debt securities, U.S. Government securities, asset-based securities, and commercial paper, which are subject to minimal credit and market risk. Unrealized gains and losses are included in other comprehensive loss. Interest on available-for-sale securities is included in interest income in the consolidated statements of operations and comprehensive loss.

Fair Value Measurements

Certain assets and liabilities of the Company are carried at fair value under U.S. GAAP. Fair value is defined as the exchange price that would be received for an asset or the exit price that would be paid to transfer a liability in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. The authoritative guidance on fair value measurements establishes a three-tier fair value hierarchy for disclosure of fair value measurements as follows:

•Level 1 – Quoted prices in active markets for identical assets or liabilities.

•Level 2 – Observable inputs (other than Level 1 quoted prices), such as quoted prices in active markets for similar assets or liabilities, quoted prices in markets that are not active for identical or similar assets or liabilities, or other inputs that are observable or can be corroborated by observable market data.

•Level 3 – Unobservable inputs that are supported by little or no market activity that are significant to determining the fair value of the assets or liabilities, including pricing models, discounted cash flow methodologies, and similar techniques.

To the extent that the valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized in Level 3. Financial assets and liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement.

The estimated fair values of the Company’s cash and cash equivalents, restricted cash, trade, and other receivables and accounts payable approximate their carrying values given their short-term nature.

Fair Value Option

The Company elected to account for the deferred consideration (GeneFab Note Receivable) and contingent consideration receivable (GeneFab Economic Share) from the GeneFab transaction under the fair value option in ASC 825, Financial Instruments (“ASC 825”). Accordingly, these instruments were recognized at their fair value at the closing of the transaction and are subsequently remeasured each reporting period with changes in fair value recorded in other income (expense) in the consolidated statements of operations and comprehensive loss until settlement. The fair value of the GeneFab Note Receivable was determined by discounting future payments under multiple probability-weighted scenarios using GeneFab’s cost of borrowing. The fair value of the GeneFab Option was determined using an option pricing method. Refer to Note 4. GeneFab Transaction, for further details of the GeneFab transaction.

Property and Equipment, Net


Asset Classification						Estimated useful Life
Small equipment						2 years
Computer equipment and software						3 years
Laboratory equipment						5-7 years
Furniture and fixtures						5-7 years
Leasehold improvements						Shorter of the lease term and the useful life

The Company capitalizes certain costs incurred during the construction phase of a project or asset into construction-in-progress. Once the construction is complete and the asset is placed into service, the Company transfers its carrying value into the appropriate fixed asset category and begins depreciating the value over its useful life.

When assets are retired or disposed of, any resulting gain or loss is included in net loss. Expenditures for maintenance and repairs are expensed as incurred.

Impairment of Long-Lived Assets

The Company evaluates its long-lived assets, such as property and equipment, net and lease ROU assets, for impairment whenever events or changes in circumstances indicate that the carrying value of assets may not be recoverable. Recoverability of these assets is measured by comparing their carrying value to the future net undiscounted cash flows the assets are expected to generate over their remaining economic life. If such assets are considered to be impaired, the amount of any impairment is measured as the difference between their carrying value and their fair value. If the useful life is shorter than originally estimated, the Company amortizes the remaining carrying value over the revised shorter useful life.

Leases

The Company determines if an arrangement is or contains a lease at inception. Operating leases are recorded on the consolidated balance sheets with right-of-use assets (“ROU”) representing the Company’s right to use an underlying asset for the lease term and lease liabilities representing the Company’s obligation to make lease payments. Operating lease ROU assets and liabilities are recognized at the lease commencement date based on the present value of lease payments over the lease term. Operating lease ROU assets also include the effect of any lease payments made prior to or on lease commencement and excludes lease incentives and initial direct costs incurred, as applicable. As the implicit rate in the Company’s leases is typically unknown, the Company uses its incremental borrowing rate based on the information available at the lease commencement date in determining the present value of future lease payments. The Company gives consideration to its credit risk, the term of the lease, and total lease payments and adjusts for the impacts of collateral as necessary when calculating its incremental borrowing rates. The lease terms may include options to extend or terminate the lease when it is reasonably certain that the Company will exercise that option. Operating lease expense is recognized on a straight-line basis over the lease term. Variable lease payments are recorded as an expense in the period incurred.

The Company has elected to not separate lease and non-lease components for any leases within its existing classes of assets and, as a result, accounts for any lease and non-lease components as a single lease component. The Company has also elected not to apply the recognition requirement for leases with a term of 12 months or less.

Revenue Recognition

Contract Revenue

Revenue is recognized when a customer obtains control of promised goods or services. The Company applies the following five steps to recognize revenue: (i) identify the contract with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to performance obligations in the contract; and (v) recognize revenue when (or as) the performance obligations are satisfied.

A performance obligation is defined as a promise to transfer a product or a service to a customer that is distinct. A product or a service is distinct if both (i) the customer can benefit from the product or the service either on its own or together with other resources that are readily available to the customer and (ii) the Company’s promise to transfer the product or the service to the customer is separately identifiable from other promises in the contract. Each distinct promise to transfer a product or a service is a unit of accounting for revenue recognition. If a promise to transfer a product or a service is not distinct from other promises in the contract, such promises should be combined into a single performance obligation. The assessment of each of these elements may require significant judgments.

Arrangements that include rights to additional goods or services that are exercisable at a customer’s discretion are generally considered options. If these options provide a material right to the customer, they are considered performance obligations. The identification of material rights requires judgments related to the determination of the value of the underlying license relative to the option exercise price, including assumptions about technical feasibility and the probability of developing a candidate that would be subject to the option rights.

The transaction price is the amount of consideration the Company is entitled to receive in exchange for the transfer of control of a product or a service to a customer. The Company’s agreements may include both fixed and variable consideration. Fixed payments are included in the transaction price, while variable consideration, such as milestone payments and fees for research services, are estimated and constrained (if required) at the inception of the contract and evaluated on a periodic basis thereafter.

If a contract has multiple performance obligations, the Company allocates the transaction price to each distinct performance obligation based on the relative stand-alone selling price (“SSP”) of the performance obligation. The Company determines SSP at contract inception and at contract modification. Determining the SSP for performance obligations requires significant judgment. Changes in the key assumptions used to determine the SSP could have a significant effect on the allocation of arrangement consideration between multiple performance obligations.

For each distinct performance obligation, revenue is recognized as the Company transfers control of the product or the service applicable to such performance obligations. In instances where the Company first receives consideration in advance of satisfying its performance obligation, the Company classifies such consideration as deferred revenue until the Company satisfies such performance obligations. In instances where the Company first satisfies its performance obligation prior to its receipt of consideration, the consideration is a contract asset recorded in prepaid expenses and other current assets on the consolidated balance sheets.

Grant Income

The Company receives government grants that reimburses the Company for certain allowable costs for funded projects. Grant income is recognized on a systematic basis over the period in which the Company recognizes qualified research and development costs that grant is intended to compensate and there is reasonable assurance that the Company will meet the terms and conditions of the grant. This income is recorded as grant income in the consolidated statements of operations and comprehensive loss.

Grant payments received in excess of grant revenue earned are recognized as deferred revenue on the balance sheets, and grant income earned in excess of grant payments received is recognized as trade and other receivables on the consolidated balance sheets.

Research and Development

Research and development costs are expensed as incurred. Research and development costs consist of salaries and other personnel-related expenses, including associated stock-based compensation expense, lab supplies and services, in-license and technology costs, consulting and sponsored research fees, manufacturing costs, facility costs and depreciation expense.

Nonrefundable advance payments for goods and services that will be used or received in future research and development activities are deferred and recognized as an expense in the period in which the related goods are delivered, or services are performed. Similarly, GeneFab prepaid expenses are recognized as an expense in the period in which the related manufacturing or research activities are performed.

The Company has acquired and may continue to acquire the rights to gene circuit or other technologies from third parties. The upfront payments to acquire a license, product, or rights, as well as any annual maintenance charges and future milestone payments, are immediately recognized as research and development expense provided that there is no alternative future use of the rights in other research and development projects.

GeneFab Option

The option granted to GeneFab as part of the GeneFab transaction meets the definition of a derivative under ASC 815, Derivatives and Hedging (“ASC 815”), and does not meet the criteria for equity classification. The derivative liability is recorded at its fair value on issuance and subsequently remeasured each reporting period with changes in fair value recorded in other income (expense) in the consolidated statements of operations and comprehensive loss until settlement. The fair value of the derivative liability was determined using a Black-Scholes option pricing model.

Commitments and Contingencies

The Company recognizes a liability with regard to loss contingencies when it believes it is probable a liability has occurred and the amount can be reasonably estimated. If some amount within a range of loss appears at the time to be a better estimate than any other amount within the range, the Company accrues that amount. When no amount within the range is a better estimate than any other amount, the Company accrues the minimum amount in the range. The Company has not recorded any such liabilities as of December 31, 2023 and 2022.

Contingent Earnout Equity

In connection with the Reverse Recapitalization and pursuant to the Merger dated as of June 8, 2022 by and among the Merger Sub and Legacy Senti, former holder of the Legacy Senti common stock and Legacy Senti preferred stock are entitled to receive as additional consideration of up to 2,000,000 shares of the Company’s Common Stock (the “Contingent Earnout Shares”), comprised of two separate tranches of 1,000,000 shares per tranche, for no consideration upon the achievement of certain share price milestones within a period of two and three years. The Contingent Earnout Shares are a form of dividend for holders of Legacy Senti common stock and Legacy Senti preferred stock. If there is a change of control within the three-year period following the closing of the Merger that results in a per share price equal to or in excess of certain share price milestones not previously met, then the Company shall issue the earnout shares to the holders of Legacy Senti common stock and preferred stock. In accordance with ASC 815 as certain terms of the contingent earnout shares were not indexed to the common stock, equity treatment is precluded and liability classification is required at the Reverse Recapitalization date and subsequently remeasured at each reporting date with changes in fair value recorded as Change in fair value of contingent earnout liability in the consolidated statements of operations and comprehensive loss. A portion of the earnout shares were granted to holders of Legacy Senti common stock that are subject to repurchase, and as of the date of the Merger were accounted for as stock-based compensation expense and expensed as there was no remaining service period.

The estimated fair value of the Contingent Earnout Shares was determined using a Monte Carlo simulation using a distribution of potential outcomes on a monthly basis over a three-year period prioritizing the most reliable information available. The assumptions utilized in the calculation were based on the achievement of certain stock

price milestones, including the current Company common stock price, expected volatility, risk-free rate, expected term and expected dividend yield.

Stock-Based Compensation Expense

The Company recognizes stock-based compensation expense related to employees and non-employees based on the grant date fair value of the awards. For awards that vest solely based on continued service, stock-based compensation expense is recognized in the consolidated statements of operations and comprehensive loss using the straight-line method. For performance and market awards, stock-based compensation expense is recognized over the requisite service period using the accelerated attribution method. No compensation expense will be recognized for awards subject to performance conditions until it is probable that the performance condition will be met.

The Company recognizes stock-based compensation expense related to purchase rights issued pursuant to its employee stock purchase plan on a straight-line basis over the offering period.

The Company has allowed specified option holders to exercise unvested options. The options that are exercised prior to vesting continue to vest according to the respective option agreement, and such unvested shares are subject to repurchase by the Company at the option holder’s original exercise price in the event the option holder's service with the Company voluntarily or involuntarily terminates.

The Company records proceeds from the early exercise of options as a current and long-term liability in the consolidated balance sheets, and reclassifies this liability to additional paid-in capital as the Company's repurchase right lapses. The shares purchased by the option holders pursuant to the early exercise of stock options are not deemed, for accounting purposes, to be outstanding until those shares have vested.

Net Loss Per Share

The Company follows the two-class method when computing net loss per share as the Company has issued shares that meet the definition of participating securities. The two-class method determines net loss per share for each class of common and participating securities according to dividends declared or accumulated and participation rights in undistributed earnings. The two-class method requires loss available to common stockholders for the period to be allocated between common and participating securities based upon their respective rights to share in undistributed earnings as if all loss for the period had been distributed.

Basic earnings per share for both continuing and discontinued operations is computed by dividing net loss from continuing operations and net income (loss) from discontinued operations attributable to common stockholders by the weighted-average number of common shares outstanding for the period. Diluted earnings per share for both continuing and discontinued operations is computed by adjusting net earnings for both continuing and discontinued operations for an allocation of the undistributed earnings and dividing it by the weighted-average number of common shares outstanding for the period, including potential dilutive common shares. For purposes of this calculation, the Company's outstanding stock options, redeemable convertible preferred stock, and potential issuance of redeemable convertible preferred stock under existing preferred stock tranches, are considered potential dilutive common shares.

The Company's participating securities contractually entitle the holders of such securities to participate in dividends but do not contractually require the holders of such securities to participate in losses of the Company. Accordingly, in periods in which the Company reports a net loss, such losses are not allocated to such participating securities. In periods in which the Company reports a net loss attributable to common stockholders, diluted net loss per share attributable to common stockholders is the same as basic net loss per share attributable to common stockholders, since dilutive common shares are not assumed to have been issued if their effect is anti-dilutive. When the Company is reporting discontinued operations, it uses net loss from continuing operations as the control number in determining whether those potential dilutive securities are dilutive or anti-dilutive.

Income Taxes

The Company accounts for income taxes under the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the consolidated financial statements. Under this method, deferred tax assets and liabilities are determined on the basis of the differences between the consolidated financial statements and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in the consolidated statement of operations and comprehensive loss in the period that includes the enactment date.

The Company recognizes net deferred tax assets to the extent that the Company believes these assets are more likely than not to be realized. In making such a determination, management considers all available positive and negative evidence, including future reversals of existing taxable temporary differences, projected future taxable income, tax-planning strategies, and results of recent operations. If management determines that the Company would be able to realize its deferred tax assets in the future in excess of their net recorded amount, management would make an adjustment to the deferred tax asset valuation allowance, which would reduce the provision for income taxes.

The Company records uncertain tax positions on the basis of a two-step process whereby (i) management determines whether it is more likely than not that the tax positions will be sustained on the basis of the technical merits of the position and (ii) for those tax positions that meet the more-likely-than-not recognition threshold, management recognizes the largest amount of tax benefit that is more than 50 percent likely to be realized upon ultimate settlement with the related tax authority. The Company recognizes interest and penalties related to unrecognized tax benefits within income tax expense. Any accrued interest and penalties are included within the related tax liability. To date, there have been no interest charges or penalties related to unrecognized tax benefits.

Recently Adopted Accounting Standards

In November 2021, the FASB issued Accounting Standards Update (ASU) No. 2021-10, Government Assistance (Topic 832): Disclosures by Business Entities about Government Assistance, which requires business entities to provide certain disclosures when they have received government assistance and use a grant or contribution accounting model by analogy to other accounting guidance. The ASU was effective January 1, 2022, and had no material impact on the Company’s consolidated financial statements and related disclosures.

In May 2021, the FASB issued ASU 2021-04 Earnings Per Share (Topic 260), Debt-Modifications and Extinguishments (Subtopic 370-50), Compensation-Stock Compensation (Topic 718), and Derivatives and Hedging-Contracts in Entity’s Own Equity (Subtopic 815-40); Issuer’s Accounting for Certain Modifications or Exchanges of Freestanding Equity-Classified Written Call Options (a consensus of the FASB Emerging Issues Task Force), which clarifies and reduces diversity in an issuer’s accounting for modifications or exchanges of freestanding equity-classified written call options that remain equity classified after modification or exchange. The ASU was effective January 1, 2022, and had no material impact on the Company’s consolidated financial statements and related disclosures.

In August 2020, the FASB issued ASU No. 2020-06, Debt—Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging—Contracts in Entity’s Own Equity (Subtopic 815-40): Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity, which simplifies accounting for convertible instruments by removing major separation models required under current GAAP. The ASU removes certain settlement conditions that are required for equity contracts to qualify for the derivative scope exception and it also simplifies the diluted earnings per share calculation in certain areas. The ASU was effective January 1, 2022, and had no material impact on the Company’s consolidated financial statements and related disclosures.

In December 2019, the FASB issued ASU No. 2019-12, Simplifying the Accounting for Income Taxes (Topic 740), which removes certain exceptions to the general principles in Topic 740 and improves consistent application of and simplifies GAAP for other areas of Topic 740 by clarifying and amending existing guidance. The ASU was effective January 1, 2022, and had no material impact on the Company’s consolidated financial statements and related disclosures.

Recent Accounting Standards

In November 2023, the FASB issued ASU No. 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures, which requires an enhanced disclosure of significant segment expenses on an annual and interim basis. This guidance is effective for annual periods beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024. Early adoption is permitted. Upon adoption, the guidance should be applied retrospectively to all prior periods presented in the financial statements.

In December 2023, the FASB issued ASU No. 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures, which improves income tax disclosures by requiring consistent categories and greater disaggregation of information in the effective tax rate reconciliation and income taxes paid disaggregated by jurisdiction. It also includes certain other amendments to improve the effectiveness of income tax disclosures. This guidance is effective for annual periods beginning after December 15, 2024. Early adoption is permitted. Upon adoption, the guidance can be applied prospectively or retrospectively.

The Company believes that the impact of recently issued accounting standards that are not yet effective will not have a material impact on its financial position or results of operations upon adoption.

Income Tax - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
Income Tax - Narrative (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Increase (decrease) in valuation allowance	$ 19,200	$ 12,300
Unrecognized tax benefits	$ 2,076	$ 1,643	$ 1,252

Summary of Significant Accounting Policies - Property and Equipment Useful Life (Details)	Dec. 31, 2023
Small equipment
Property, Plant and Equipment [Line Items]
Useful life	2 years
Computer equipment and software
Property, Plant and Equipment [Line Items]
Useful life	3 years
Lab equipment \| Minimum
Property, Plant and Equipment [Line Items]
Useful life	5 years
Lab equipment \| Maximum
Property, Plant and Equipment [Line Items]
Useful life	7 years
Furniture and fixtures \| Minimum
Property, Plant and Equipment [Line Items]
Useful life	5 years
Furniture and fixtures \| Maximum
Property, Plant and Equipment [Line Items]
Useful life	7 years

Operating Leases - Narrative (Details) $ in Thousands	12 Months Ended		29 Months Ended
Operating Leases - Narrative (Details) $ in Thousands	Dec. 31, 2023 USD ($) tradingDay	Dec. 31, 2022 USD ($)	Dec. 31, 2023 USD ($)	Jun. 03, 2021
Lessee, Lease, Description [Line Items]
Lease term				11 years
Sublease income	$ 2,323	$ 0
JPMorgan Chase Bank
Lessee, Lease, Description [Line Items]
Letters of credit	2,900		$ 2,900
Silicon Valley Bank
Lessee, Lease, Description [Line Items]
Letters of credit	$ 500		$ 500
Corporate Headquarters
Lessee, Lease, Description [Line Items]
Lease term	8 years		8 years
Lease renewal term	8 years		8 years
Alameda
Lessee, Lease, Description [Line Items]
Lease term	11 years		11 years
Lease renewal term	5 years		5 years
Number of renewal options \| tradingDay	2
Tenant improvement allowance remaining	$ 3,400	14,100
Tenant improvement allowance	17,500	$ 17,500	$ 17,500
Tenant improvement allowance utilized			$ 17,500
Alameda \| GeneFab
Lessee, Lease, Description [Line Items]
Sublease income to be earned	44,100
Sublease income	2,000
Variable sublease income	$ 300

Fair Value Measurements - Summary of Changes in Fair Value of Level 3 Financial Instruments, Liabilities (Details) - Level 3 - USD ($) $ in Thousands	5 Months Ended	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2023
Contingent Earnout Liability
Change in Preferred Stock Tranche Liability [Roll Forward]
Beginning balance		$ (227)
Change in fair value included in other income (expense)		207
Ending balance	$ (20)	(20)
Derivative Financial Instruments, Liabilities \| GeneFab \| Equity Option
Change in Preferred Stock Tranche Liability [Roll Forward]
Beginning balance	(9,649)
Change in fair value included in other income (expense)	3,318
Ending balance	$ (6,331)	$ (6,331)

Other Financial Statement information - Schedule of Accrued Expenses and Other Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Accrued professional and service fees related to facility construction	$ 0	$ 7,342
Accrued professional and service fees other	3,555	3,496
Accrued employee-related expenses	2,363	1,709
Other accrued expenses	9	29
Total accrued expenses and other current liabilities	$ 5,927	$ 12,576

Commitment and Contingencies	12 Months Ended
Commitment and Contingencies	Dec. 31, 2023
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies In the ordinary course of business, the Company enters into contractual agreements with third parties that include non-cancelable payment obligations, for which the Company is liable in future periods. On June 3, 2021, the Company entered into a lease agreement for a new cGMP facility in Alameda, California to support planned initial clinical trials for our product candidates. Refer to Note 7. Operating Leases, for further details of the leases. The lease will expire in 2032 with future undiscounted operating lease payments of $46.0 million over an initial lease period of eleven years. In 2021, the Company entered into a three-year collaboration and option agreement with BlueRock Therapeutics LP (“BlueRock”) under which the Company granted BlueRock an option to acquire an exclusive or non-exclusive license to develop, manufacture and commercialize cell therapy products. Refer to Note 16. Related Parties, for further details of the related parties. In consideration for the option, the Company is responsible for up to $10.0 million in costs and expenses incurred over the three-year term. As of December 31, 2023, purchase commitments related to sponsored research agreements amounted to approximately $0.3 million. The Company has entered into license agreements under which they are obligated to make annual maintenance payments of $0.2 million and specified milestone and royalty payments. Future milestone and royalty payments under these agreements are not considered contractual obligations since the payments under these agreements are contingent upon future events, such as the Company’s achievement of specified development, regulatory, and sales milestones, or generating product sales. As of December 31, 2023, the Company is unable to estimate the timing or likelihood of achieving these milestones or generating future product sales. In connection with the Merger, former holders of Legacy Senti common stock and preferred stock may receive up to 2,000,000 additional shares of the Company’s common stock in the aggregate, in two equal tranches of 1,000,000 shares of common stock per tranche. Refer to Note 9. Stockholders’ Equity (Deficit), for further details of the contingent earnout liability. Legal Proceedings The Company is subject to claims and assessments from time to time in the ordinary course of business but does not believe that any such matters, individually or in the aggregate, will have a material adverse effect on the Company’s financial position, results of operations, or cash flows. Indemnification In the ordinary course of business, the Company enters into agreements that may include indemnification provisions. Pursuant to such agreements, the Company may indemnify, hold harmless and defend an indemnified party for losses suffered or incurred by the indemnified party. Some of the provisions will limit losses to those arising from third-party actions. In some cases, the indemnification will continue after the termination of the agreement. The maximum potential amount of future payments the Company could be required to make under these provisions is not determinable. The Company has never incurred material costs to defend lawsuits or settle claims related to these indemnification provisions and has never accrued any liabilities related to such obligations in its consolidated financial statements. The Company has also entered into indemnification agreements with its directors and officers that may require the Company to indemnify its directors and officers against liabilities that may arise by reason of their status or service as directors or officers to the fullest extent permitted by Delaware corporate law. The Company currently has directors’ and officers’ insurance.

Commitment and Contingencies (Details) $ in Thousands			12 Months Ended
Commitment and Contingencies (Details) $ in Thousands	Jun. 08, 2022 tranche shares	May 21, 2021 USD ($)	Dec. 31, 2023 USD ($)	Jun. 03, 2021 USD ($)
Long-Term Purchase Commitment [Line Items]
Total undiscounted lease payments			$ 52,597	$ 46,000
Operating lease, term of contract				11 years
Annual maintenance payments			200
Maximum contingent earnout (in shares) \| shares	2,000,000
Number of tranches of contingent earnout shares \| tranche	2
Number of contingent earnout shares per tranche (in shares) \| shares	1,000,000
BlueRock \| Research and Development Arrangement
Long-Term Purchase Commitment [Line Items]
Long-term purchase commitment amount			$ 300
BlueRock \| Collaborative Arrangement, Transaction with Party to Collaborative Arrangement
Long-Term Purchase Commitment [Line Items]
Term of agreement (in years)		3 years
Expected costs and expenses incurred		$ 10,000

Stockholders’ Equity (Deficit) - Contingent Earnout Equity (Details) $ / shares in Units, $ in Thousands		12 Months Ended
	Jun. 08, 2022 USD ($) tranche $ / shares shares	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)
Business Acquisition, Contingent Consideration [Line Items]
Maximum contingent earnout (in shares) \| shares	2,000,000
Number of tranches of contingent earnout shares \| tranche	2
Number of contingent earnout shares per tranche (in shares) \| shares	1,000,000
Number of trading days	20 days
Number of consecutive trading days	30 days
Threshold of years for change of control (in years)	3 years
Fair value of contingent earnout shares	$ 9,800
Contingent consideration, liability	9,700
Fair value of contingent earnout shares	$ 100
Change in fair value of contingent earnout liability		$ 207	$ 9,461
Contingent Consideration, Tranche One
Business Acquisition, Contingent Consideration [Line Items]
Closing stock price to trigger contingent earnout shares (in dollars per share) \| $ / shares	$ 15.00
Term (in years)	2 years
Contingent Consideration, Tranche Two
Business Acquisition, Contingent Consideration [Line Items]
Closing stock price to trigger contingent earnout shares (in dollars per share) \| $ / shares	$ 20.00
Term (in years)	3 years

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Cash flows from operating activities
Net loss	$ (71,058)	$ (58,210)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	3,561	1,398
Amortization of operating lease right-of-use assets	1,868	2,522
Accretion of discount on short-term investments	(1,069)	(356)
Gain on extinguishment of convertible notes	0	(1,289)
Gain on disposal of business	(21,862)	0
Change in fair value of contingent earnout liability	(207)	(9,461)
Impairment of long-lived assets	25,962	0
Stock-based compensation expense	9,670	16,392
Issuance of common stock for Common Stock Purchase Agreement fee	0	196
Other non-cash charges	35	8
Changes in assets and liabilities:
Accounts payable	(290)	186
Accrued expenses and other current liabilities	716	2,055
GeneFab sublease deferred income - related party	689	0
Deferred revenue	(799)	(1,033)
Operating lease liabilities	484	14,129
Net cash from operating activities	(52,395)	(34,896)
Cash flows from investing activities
Purchases of short-term investments	(17,990)	(40,585)
Maturity of short-term investments	60,000	0
Purchases of property and equipment	(12,038)	(41,374)
Proceeds from sale of property and equipment	105	0
Net cash from investing activities	30,077	(81,959)
Cash flows from financing activities
Proceeds from Merger and related PIPE financing, net of transaction costs	0	111,976
Proceeds from issuance of common stock upon exercise of stock options	0	521
Proceeds from issuance of common stock under Common Stock Purchase Agreement	512	728
Proceeds from issuance of common stock under Employee Stock Purchase Plan (ESPP)	375	151
Proceeds from issuance of convertible notes	0	5,175
Principal finance lease payments	(108)	0
Net cash from financing activities	779	118,551
Net (decrease) increase in cash and cash equivalents	(21,539)	1,696
Cash, cash equivalents, and restricted cash, beginning of period	60,987	59,291
Cash, cash equivalents, and restricted cash, end of period	39,448	60,987
Reconciliation of cash, cash equivalents and restricted cash
Cash and cash equivalents	35,926	57,621
Restricted cash	3,522	3,366
Total cash, cash equivalents and restricted cash	39,448	60,987
Supplemental disclosures of noncash financing and investing items
Purchases of property and equipment in accounts payable and accrued expenses and other current liabilities	15	8,153
GeneFab Notes Receivable
Adjustments to reconcile net loss to net cash used in operating activities:
Change in fair value	(626)	0
GeneFab Economic Share
Adjustments to reconcile net loss to net cash used in operating activities:
Change in fair value	(16)	0
GeneFab Option
Adjustments to reconcile net loss to net cash used in operating activities:
Change in fair value	(3,318)	0
Nonrelated Party
Changes in assets and liabilities:
Accounts receivable	507	(131)
Prepaid expenses and other assets	681	(1,302)
Related Party
Changes in assets and liabilities:
Accounts receivable	(1,436)	0
Prepaid expenses and other assets	$ 4,113	$ 0

Fair Value Measurements - Summary of the Estimated Fair Value of Cash Equivalents, Restricted Cash, And Short-Term Investments (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Debt Securities, Available-for-Sale [Line Items]
Cash, cash equivalents, and restricted cash	$ 39,448	$ 60,987	$ 59,291
Unrealized Gain	0	5
Unrealized Loss	0	(4)
Cash and cash equivalents and debt securities, available-for-sale, adjusted cost	39,448	101,928
Cash and cash equivalents and debt securities, available-for-sale, fair value	39,448	101,929
Cash and cash equivalents
Debt Securities, Available-for-Sale [Line Items]
Cash and cash equivalents and debt securities, available-for-sale, fair value	35,926	57,621
Restricted cash
Debt Securities, Available-for-Sale [Line Items]
Cash and cash equivalents and debt securities, available-for-sale, fair value	3,522	3,366
Short-term investments
Debt Securities, Available-for-Sale [Line Items]
Cash and cash equivalents and debt securities, available-for-sale, fair value	0	40,942
Level 1
Debt Securities, Available-for-Sale [Line Items]
Cash	4,205
Cash, cash equivalents, and restricted cash	35,243	45,412
Level 1 \| Cash and cash equivalents
Debt Securities, Available-for-Sale [Line Items]
Cash	4,205
Cash, cash equivalents, and restricted cash	31,721	42,046
Level 1 \| Restricted cash
Debt Securities, Available-for-Sale [Line Items]
Cash	0
Cash, cash equivalents, and restricted cash	3,522	3,366
Level 1 \| Short-term investments
Debt Securities, Available-for-Sale [Line Items]
Cash	0
Cash, cash equivalents, and restricted cash	0	0
Level 1 \| Money market funds
Debt Securities, Available-for-Sale [Line Items]
Cash, cash equivalents, and restricted cash	35,243	45,412
Level 1 \| Money market funds \| Cash and cash equivalents
Debt Securities, Available-for-Sale [Line Items]
Cash, cash equivalents, and restricted cash	31,721	42,046
Level 1 \| Money market funds \| Restricted cash
Debt Securities, Available-for-Sale [Line Items]
Cash, cash equivalents, and restricted cash	3,522	3,366
Level 1 \| Money market funds \| Short-term investments
Debt Securities, Available-for-Sale [Line Items]
Cash, cash equivalents, and restricted cash	$ 0	0
Level 2
Debt Securities, Available-for-Sale [Line Items]
Adjusted Cost		56,516
Unrealized Gain		5
Unrealized Loss		(4)
Estimated Fair Value		56,517
Level 2 \| Cash and cash equivalents
Debt Securities, Available-for-Sale [Line Items]
Estimated Fair Value		15,575
Level 2 \| Restricted cash
Debt Securities, Available-for-Sale [Line Items]
Estimated Fair Value		0
Level 2 \| Short-term investments
Debt Securities, Available-for-Sale [Line Items]
Estimated Fair Value		40,942
Level 2 \| U.S. Treasury securities
Debt Securities, Available-for-Sale [Line Items]
Adjusted Cost		14,866
Unrealized Gain		4
Unrealized Loss		(3)
Estimated Fair Value		14,867
Level 2 \| U.S. Treasury securities \| Cash and cash equivalents
Debt Securities, Available-for-Sale [Line Items]
Estimated Fair Value		0
Level 2 \| U.S. Treasury securities \| Restricted cash
Debt Securities, Available-for-Sale [Line Items]
Estimated Fair Value		0
Level 2 \| U.S. Treasury securities \| Short-term investments
Debt Securities, Available-for-Sale [Line Items]
Estimated Fair Value		14,867
Level 2 \| U.S. agency securities
Debt Securities, Available-for-Sale [Line Items]
Adjusted Cost		5,938
Unrealized Gain		0
Unrealized Loss		0
Estimated Fair Value		5,938
Level 2 \| U.S. agency securities \| Cash and cash equivalents
Debt Securities, Available-for-Sale [Line Items]
Estimated Fair Value		3,983
Level 2 \| U.S. agency securities \| Restricted cash
Debt Securities, Available-for-Sale [Line Items]
Estimated Fair Value		0
Level 2 \| U.S. agency securities \| Short-term investments
Debt Securities, Available-for-Sale [Line Items]
Estimated Fair Value		1,955
Level 2 \| Commercial paper
Debt Securities, Available-for-Sale [Line Items]
Adjusted Cost		28,122
Unrealized Gain		0
Unrealized Loss		0
Estimated Fair Value		28,122
Level 2 \| Commercial paper \| Cash and cash equivalents
Debt Securities, Available-for-Sale [Line Items]
Estimated Fair Value		5,994
Level 2 \| Commercial paper \| Restricted cash
Debt Securities, Available-for-Sale [Line Items]
Estimated Fair Value		0
Level 2 \| Commercial paper \| Short-term investments
Debt Securities, Available-for-Sale [Line Items]
Estimated Fair Value		22,128
Level 2 \| Corporate debt securities
Debt Securities, Available-for-Sale [Line Items]
Adjusted Cost		7,590
Unrealized Gain		1
Unrealized Loss		(1)
Estimated Fair Value		7,590
Level 2 \| Corporate debt securities \| Cash and cash equivalents
Debt Securities, Available-for-Sale [Line Items]
Estimated Fair Value		5,598
Level 2 \| Corporate debt securities \| Restricted cash
Debt Securities, Available-for-Sale [Line Items]
Estimated Fair Value		0
Level 2 \| Corporate debt securities \| Short-term investments
Debt Securities, Available-for-Sale [Line Items]
Estimated Fair Value		$ 1,992

Net Loss Per Share - Antidilutive Securities Excluded from Computation of Earnings Per Share (Details) - shares	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total	33,496,524	12,429,123
Stock options to purchase common stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total	11,582,938	9,875,675
Unvested early exercised options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total	54,860	105,500
Restricted Stock Units (RSUs)
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total	225,282	447,948
Contingent earnout common stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total	2,000,000	2,000,000
GeneFab Option
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total	19,633,444	0

Convertible Note (Details) - USD ($) $ / shares in Units, $ in Thousands		12 Months Ended
	Jun. 08, 2022	Dec. 31, 2023	Dec. 31, 2022	May 19, 2022
Convertible Debt [Line Items]
Gain on extinguishment of convertible notes		$ 0	$ 1,289
Common Class A
Convertible Debt [Line Items]
Conversion of redeemable convertible preferred stock into common stock in connection with the Reverse Recapitalization, net of transaction costs (in shares)	517,500
Common stock share price (in dollars per share)	$ 10.00
May 2022 Note
Convertible Debt [Line Items]
Principal amount of unsecured convertible promissory note				$ 5,200
Annual rate (in percent)				3.00%
Conversion price (in dollars per share)				$ 10.00
Conversion price (in percent)				80.00%
Gain on extinguishment of convertible notes	$ 1,300

Income Tax - Unrecognized Tax Benefits Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at beginning of the year	$ 1,643	$ 1,252
Decrease related to prior year tax positions	(243)	(109)
Increase related to current year tax positions	676	500
Balance at end of the year	$ 2,076	$ 1,643

Operating Leases - Other Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Leases [Abstract]
Operating cash flows net inflows and (outflows) from operating lease	$ (2,922)	$ 11,363
ROU assets obtained in exchange for operating lease obligations (including remeasurement of ROU and lease liabilities due to changes in the timing of receipt of lease incentives)	$ (5)	$ 231
Weighted-average remaining lease term	7 years 6 months	8 years 2 months 12 days
Weighted-average discount rate	9.20%	9.10%

Reverse Recapitalization

12 Months Ended

Dec. 31, 2023

Business Combination and Asset Acquisition [Abstract]

Reverse Recapitalization

On June 8, 2022, Merger Sub, a wholly-owned subsidiary of Dynamics, merged with Legacy Senti, with Legacy Senti surviving as a wholly-owned subsidiary of Dynamics. At the effective time of the Merger:

•each outstanding share of Legacy Senti common stock was converted into approximately 0.1957 shares of the Company’s common stock;

•each outstanding share of preferred stock of Legacy Senti was cancelled and converted into the aggregate number of shares of the Company’s common stock that would be issued upon conversion of the shares of Legacy Senti preferred stock based on the applicable conversion ratio immediately prior to the effective time, multiplied by approximately 0.1957;

•each outstanding option to purchase Legacy Senti common stock was converted into an option to purchase a number of shares of the Company’s common stock equal to the number of shares of Legacy Senti common stock subject to such option multiplied by approximately 0.1957, rounded down to the nearest whole share, at an exercise price per share equal to the current exercise price per share for such option divided by approximately 0.1957, rounded up to the nearest whole cent; and

•all shares of Dynamics Class A common stock were redesignated as common stock, par value $0.0001 per share, of the Company.

Former holders of the Legacy Senti common stock and preferred stock are eligible to receive up to an aggregate of 2,000,000 additional shares of the Company’s common stock in the aggregate in two equal tranches of 1,000,000 shares if the volume-weighted average closing sale price of the common stock is greater than or equal to $15.00 and $20.00, respectively, for any 20 trading days within any 30 consecutive trading day period. The first and second tranche term is two and three years, respectively, from the closing of the Merger. If there is a change of control within the three-year period following the closing of the Merger that results in a per share price equal to or in excess of the $15.00 and $20.00 share price milestones not previously met, then the Company shall issue the earnout shares to the holders of Legacy Senti common stock and preferred stock. Refer to Note 9, Stockholders’ Equity (Deficit), for further details of the contingent earnout liability.

In association with the Merger, Dynamics entered into subscription agreements (the “Subscription Agreements”) with certain investors (the “PIPE Investors”). Pursuant to the Subscription Agreements, the PIPE Investors purchased an aggregate of 5,060,000 shares of the Company’s common stock (the “PIPE Shares”) in a private placement at a price of $10.00 per share for an aggregate purchase price of $50.6 million (the “PIPE Financing”). The PIPE Financing was consummated in connection with the Merger.

Concurrently with the closing of the Merger, the unsecured convertible promissory note (the “May 2022 Note”) in the principal amount of $5.2 million that was previously issued by Legacy Senti to Bayer Healthcare LLC

(“Bayer”) on May 19, 2022 was automatically cancelled and exchanged for 517,500 shares of Class A Common Stock (the “Note Exchange”) at a price of $10.00 per share. The shares of Class A Common Stock issued in the Note Exchange are entitled to the same registration rights granted to the PIPE Investors with respect to the PIPE Shares. Refer to Note 8. Convertible Note, for further details of the convertible note.

The number of shares of the Company’s common stock outstanding immediately following the consummation of the Merger was:


	Shares



Owned by Dynamics’ stockholders	14,915,963
Issued to PIPE Investors	5,060,000
Issued to Bayer in connection with convertible note cancellation and exchange	517,500
Issued to Legacy Senti stockholders	23,163,614	(1)
Early exercised shares subject to repurchase	(288,807)
Total shares of common stock immediately after Merger	43,368,270

________________

(1) Includes 19,517,988 shares of common stock issued upon conversion of Legacy Senti’s redeemable convertible preferred stock.

The Merger was accounted for as a reverse recapitalization in accordance with U.S. GAAP. Under this method of accounting, Dynamics was treated as the acquired company for financial reporting purposes and Legacy Senti was treated as the acquiror. This determination was primarily based on the fact that subsequent to the Merger, the Legacy Senti stockholders hold a majority of the voting rights of the combined company, Legacy Senti comprises all of the ongoing operations of the combined company, Legacy Senti comprises a majority of the carryover governing body of the combined company, and Legacy Senti’s senior management comprises all of the senior management of the combined company. Accordingly, for accounting purposes, the Merger was treated as the equivalent of Legacy Senti issuing shares for the net assets of Dynamics, accompanied by a recapitalization. The net assets of Dynamics were stated at historical costs. No goodwill or other intangible assets were recorded. Operations prior to the Merger are those of Legacy Senti.

In connection with the Merger, the Company raised $140.7 million in proceeds from the Merger and related PIPE Financing, including the Bayer convertible note cancellation and exchange. Transaction costs totaling $23.5 million consisting of banking, legal, and other professional fees were deducted from the funds raised, of which $4.8 million was incurred by the Company and the remainder by Dynamics. In addition, there were no unpaid transaction costs included in accounts payable and accrued expenses as of December 31, 2022.

Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2023

Share-Based Payment Arrangement [Abstract]

Share-Based Payment Arrangement, Option, Activity

The following table summarizes the Company’s stock option activity and related information under all equity plans, excluding performance and market awards:


	Number of Options	Weighted-Average Exercise Price		Weighted-Average Remaining Contractual Life (Years)	Aggregate Intrinsic Value (in thousands)
Outstanding at December 31, 2022	4,191,426	$	3.18	9.1	$	6
Granted	2,914,196	$	1.60

Forfeited	(869,943)	$	3.33
Outstanding at December 31, 2023	6,235,679	$	2.42	7.2	$	2
Vested and exercisable at December 31, 2023	2,270,135	$	3.00	6.7	$	2

Share-Based Payment Arrangement, Outstanding Award, Activity, Excluding Option


	Number of Options	Weighted-Average Exercise Price		Weighted-Average Remaining Contractual Life (Years)	Aggregate Intrinsic Value (in thousands)
Outstanding at December 31, 2022	5,368,501	$	9.92	9.0	$	—
Granted	—	$	—

Forfeited	(336,990)	$	9.92
Outstanding at December 31, 2023	5,031,511	$	9.92	7.5	$	—
Vested and exercisable at December 31, 2023	2,009,756	$	9.92	7.3	$	—

The following table summarizes the Company’s restricted stock units activity and related information under all equity plans:


	Number of Restricted Stock Units	Weighted-Average Grant Date Fair Value
Outstanding at December 31, 2022	447,948	$	2.50


Forfeited	(222,666)	$	—
Outstanding at December 31, 2023	225,282	$	2.50

Schedule of Share-Based Payment Award, Stock Options, Valuation Assumptions

The assumptions used to determine the grant date fair value of non-market based, stock options granted were as follows, presented on a weighted-average basis:


	Years Ended December 31,
	2023	2022
Expected term (in years)	5.9	5.8
Expected volatility	82.6%	78.8%
Risk-free interest rate	3.6%	3.2%
Dividend yield	—	—

Share-Based Payment Arrangement, Expensed and Capitalized, Amount

Total stock-based compensation expense was as follows (in thousands):


	Years Ended December 31,
	2023		2022
General and administrative	$	10,236	$	13,340
Research and development	1,456		2,222
Total stock-based compensation expense	$	11,692	$	15,562

Other Financial Statement information (Tables)

12 Months Ended

Dec. 31, 2023

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Schedule of Prepaid Expenses and Other Current Assets

Prepaid Expenses and Other Current Assets

Prepaid expenses and other current assets consisted of the following (in thousands):


	December 31,

	2023		2022
Prepaid expenses (including prepaid rent)	$	2,546	$	1,871
Deposits	42		1,209

Other	195		101
Total prepaid expenses and other current assets	$	2,783	$	3,181

Schedule of Property and Equipment, Net


Asset Classification						Estimated useful Life
Small equipment						2 years
Computer equipment and software						3 years
Laboratory equipment						5-7 years
Furniture and fixtures						5-7 years
Leasehold improvements						Shorter of the lease term and the useful life

Property and equipment, net consisted of the following (in thousands):


	December 31,

	2023		2022
Lab equipment	$	8,186	$	7,855
Leasehold improvements	22,648		1,869
Computer equipment and software	360		374
Furniture and fixtures	326		326
Construction in progress	—		43,892
Property and equipment at cost	31,520		54,316
Less: accumulated depreciation	(6,182)		(2,955)
Property and equipment, net	$	25,338	$	51,361

Schedule of Accrued Expenses and Other Liabilities

Accrued expenses and other current liabilities consisted of the following (in thousands):


	December 31,

	2023		2022
Accrued professional and service fees related to facility construction	$	—	$	7,342
Accrued professional and service fees other	3,555		3,496
Accrued employee-related expenses	2,363		1,709
Other accrued expenses	9		29
Total accrued expenses and other current liabilities	$	5,927	$	12,576

Fair Value Measurements - Summary of Changes in Fair Value of Level 3 Financial Instruments, Assets (Details) - GeneFab - Level 3 $ in Thousands	5 Months Ended
	Dec. 31, 2023 USD ($)
Notes Receivable
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	$ 16,614
Change in fair value included in other income (expense)	626
Ending balance	17,240
Contingent Consideration Receivable
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	1,800
Change in fair value included in other income (expense)	16
Ending balance	$ 1,816

Stockholders’ Equity (Deficit) (Tables)

12 Months Ended

Dec. 31, 2023

Equity [Abstract]

Temporary Equity

The Company’s redeemable convertible preferred stock consisted of the following as of December 31, 2021 (in thousands, except share and per share amounts):


	December 31, 2021
	Issue Price Per Share		Shares Authorized	Shares Issued and Outstanding	Net Carrying Value		Aggregate Liquidation Preference
Series A	$	1.6427	6,888,563	6,888,563	$	57,408	$	57,822
Series B	$	1.6427	12,629,427	12,629,425	114,425		106,012
Total			19,517,990	19,517,988	$	171,833	$	163,834

Schedule Of Shares Reserved For Future Issuance

At December 31, 2023 and December 31, 2022, the Company was authorized to issue 500,000,000 shares of common stock, all at a par value of $0.0001 per share, and had reserved the following shares for future issuance:


	December 31,

	2023	2022
Series A and B redeemable convertible preferred stock	—	—
Common Stock Purchase Agreement	7,327,049	8,327,049
Common stock options issued and outstanding	11,582,938	9,875,675
Restricted stock units outstanding	225,282	447,948
Common stock shares available for future issuance under equity plans	3,672,276	2,948,472
Common stock shares available for future issuance under the 2022 Employee Stock Purchase Plan (the "ESPP")	336,320	481,627
Contingent earnout common stock	2,000,000	2,000,000
GeneFab Option	19,633,444	—
Unvested early exercised common stock	54,860	105,500
Total	44,832,169	24,186,271

Schedule of Business Acquisitions by Acquisition, Contingent Consideration

Assumptions used in the valuation are described below:


	December 31,
	2023		2022

Current stock price	$	0.66	$	1.41
Expected share price volatility	113.5%		85.0%
Risk-free interest rate	4.51%		4.32%
Estimated dividend yield	0.0%		0.0%
Expected term (years)	1.5		2.4

Stockholders’ Equity (Deficit)

12 Months Ended

Dec. 31, 2023

Equity [Abstract]

Stockholders’ Equity (Deficit)

Redeemable Convertible Preferred Stock

The Company’s redeemable convertible preferred stock consisted of the following as of December 31, 2021 (in thousands, except share and per share amounts):


	December 31, 2021
	Issue Price Per Share		Shares Authorized	Shares Issued and Outstanding	Net Carrying Value		Aggregate Liquidation Preference
Series A	$	1.6427	6,888,563	6,888,563	$	57,408	$	57,822
Series B	$	1.6427	12,629,427	12,629,425	114,425		106,012
Total			19,517,990	19,517,988	$	171,833	$	163,834

In connection with the Merger, all previously issued and outstanding redeemable convertible preferred stock was converted on June 8, 2022 into an equivalent number of shares of common stock of the Company on a one-to-one basis, then multiplied by the Exchange Ratio pursuant to the Merger Agreement. Refer to Note 3, Reverse Recapitalization, for further details of the Merger.

Common Stock

Holders of common stock are entitled to one vote per share, and to receive dividends and, upon liquidation or dissolution, are entitled to receive all assets available for distribution to stockholders. The holders have no preemptive or other subscription rights, and there are no redemption or sinking fund provisions with respect to such shares. Common stock is subordinate to the redeemable convertible preferred stock with respect to dividend rights and rights upon liquidation, winding up, and dissolution of the Company. Through December 31, 2023, no cash dividends have been declared or paid.


	December 31,

	2023	2022
Series A and B redeemable convertible preferred stock	—	—
Common Stock Purchase Agreement	7,327,049	8,327,049
Common stock options issued and outstanding	11,582,938	9,875,675
Restricted stock units outstanding	225,282	447,948
Common stock shares available for future issuance under equity plans	3,672,276	2,948,472
Common stock shares available for future issuance under the 2022 Employee Stock Purchase Plan (the "ESPP")	336,320	481,627
Contingent earnout common stock	2,000,000	2,000,000
GeneFab Option	19,633,444	—
Unvested early exercised common stock	54,860	105,500
Total	44,832,169	24,186,271

On June 8, 2022, upon the Closing, all of the outstanding redeemable convertible preferred stock was converted to Common Stock pursuant to the conversion rate effective immediately prior to the Merger and the Exchange Ratio and the remaining amount was reclassified to additional paid-in capital. Refer to Note 3. Reverse Recapitalization, for further details of the Merger.

Preferred Stock

In connection with the close of the Merger, the Company’s Amended and Restated Certificate of Incorporation provides the Company’s board of directors with the authority to issue $0.0001 par value preferred stock in one or more series and to establish from time to time the number of shares to be included in each such series, by adopting a resolution and filing a certification of designations. Voting powers, designations, powers, preferences and relative, participating, optional, special and other rights shall be stated and expressed in such resolutions. There were 10,000,000 shares designated as preferred stock and none were outstanding as of December 31, 2023 and December 31, 2022.

Common Stock Purchase Agreement

On August 31, 2022, the Company entered into a Common Stock Purchase Agreement and a Registration Rights Agreement (collectively referred to as the “Purchase Agreement”) with Chardan Capital Markets LLC (“Chardan”). Pursuant to the Purchase Agreement, the Company has the right, in its sole discretion, to sell to Chardan up to the lesser of (i) $50.0 million of newly issued shares of the Company’s common stock, and (ii) the Exchange Cap (as defined below) (subject to certain conditions and limitations), from time to time during the 36-month term of the Purchase Agreement. Under the applicable NASDAQ rules, the Company may not issue to Chardan under the Purchase Agreement more than 8,727,049 shares of common stock, which number of shares is equal to 19.99% of the common shares outstanding immediately prior to the execution of the Purchase Agreement unless certain exceptions are met (the “Exchange Cap”). The purchase price of the shares of common stock will be determined by reference to the Volume Weighted Average Price (“VWAP”) of the common stock during the applicable purchase date, less a fixed 3% discount to such VWAP. However, the total shares to be purchased on any day may not exceed 20% of the trading volume, and the total purchase price on any day may not exceed $3.0 million. As consideration for Chardan’s commitment to purchase shares of common stock at the Company’s direction upon the terms and subject to the conditions set forth in the Purchase Agreement, the Company issued 100,000 shares of its common stock to Chardan and paid a $0.4 million document preparation fee, upon execution of the Purchase Agreement. The Company recognized an expense of $0.7 million within general and administrative expenses in the Company’s consolidated statements of operations and comprehensive loss for the Chardan related costs and legal fees incurred in connection with the execution of the agreement.

Other than the issuance of the commitment shares of the Company’s common stock to Chardan, the Company issued 1,300,000 Class A common stock through December 31, 2023 aggregating to net proceeds of $1.2 million under the Common Stock Purchase Agreement.

Contingent Earnout Equity

Following the closing of the Merger, former holders of Legacy Senti common stock and preferred stock may receive up to 2,000,000 additional shares of the Company’s common stock in the aggregate, in two equal tranches of 1,000,000 shares of common stock per tranche. The first and second tranches are issuable if the closing volume weighted average price (“VWAP”) per share of common stock quoted on the Nasdaq (or the exchange on which the shares of common stock are then listed) is greater or equal to $15.00 and $20.00, respectively over any twenty trading days within any thirty-day trading period. The first and second tranche term is two and three years, respectively, from the closing of the Merger. If there is a change of control within the three-year following the closing of the Merger that results in a per share price equal to or in excess of the $15.00 and $20.00 share price milestones not previously met, then Company shall issue the earnout shares to the holders of Legacy Senti common stock and preferred stock.

The estimated fair value of the total Contingent Earnout Shares at the Closing on June 8, 2022, was $9.8 million based on a Monte Carlo simulation valuation model. Of this amount, $9.7 million was accounted for as a Contingent Earnout Liability because the triggering events that determine the number of Contingent Earnout Shares required to be issued include events that are not solely indexed to the common stock of the Company. The remaining balance of $0.1 million relates to holders of Legacy Senti common stock that are subject to repurchase were accounted for as stock-based compensation expense and recorded as an expense, as there was no remaining service period. The Contingent Earnout Liability was remeasured to fair value, resulting in the recording of a non-cash gain of

$0.2 million for the year ended December 31, 2023 and non-cash gain of $9.5 million for the year ended December 31, 2022, classified within change in fair value of contingent earnout liability in the consolidated statements of operations and comprehensive loss.

Assumptions used in the valuation are described below:


	December 31,
	2023		2022

Current stock price	$	0.66	$	1.41
Expected share price volatility	113.5%		85.0%
Risk-free interest rate	4.51%		4.32%
Estimated dividend yield	0.0%		0.0%
Expected term (years)	1.5		2.4

- Definition

The entire disclosure for equity.

+ References

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+ Details

Stockholders’ Equity (Deficit) - Common and Preferred Stock (Details)	12 Months Ended
	Dec. 31, 2023 USD ($) vote $ / shares shares	Dec. 31, 2022 $ / shares shares	Jun. 08, 2022
Equity [Abstract]
Conversion ratio			1
Number of votes per common stock \| vote	1
Cash dividends declared and paid, common stock \| $	$ 0
Preferred stock, par value per share (in dollars per share) \| $ / shares	$ 0.0001	$ 0.0001
Preferred stock, shares authorized (in shares)	10,000,000
Preferred stock, shares outstanding (in shares)	0	0

Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Revenue
Contract revenue	$ 1,978	$ 3,286
Grant income	583	1,000
Total revenue	2,561	4,286
Operating expenses
Research and development (included related party cost of $3,113 and $—, respectively)	32,150	28,145
General and administrative	37,176	38,225
Loss on impairment of fixed assets	25,962	0
Total operating expenses	95,288	66,370
Loss from operations	(92,727)	(62,084)
Other income (expense)
Interest income, net	2,864	1,701
Change in fair value of contingent earnout liability	207	9,461
Gain on extinguishment of convertible notes	0	1,289
GeneFab sublease income - related party	2,323	0
Other income (expense)	(33)	(32)
Total other income (expense), net	9,321	12,419
Net loss from continuing operations	(83,406)	(49,665)
Net income (loss) from discontinued operations	12,348	(8,545)
Net loss	(71,058)	(58,210)
Other comprehensive gain (loss)
Unrealized gain (loss) on investments	(1)	1
Comprehensive loss	$ (71,059)	$ (58,209)
Net loss per share from continuing operations, basic (in dollars per share)	$ (1.88)	$ (1.90)
Net loss per share from continuing operations, diluted (in dollars per share)	(1.88)	(1.90)
Net income (loss) per share from discontinued operations, basic (in dollars per share)	0.28	(0.33)
Net income (loss) per share from discontinued operations, diluted (in dollars per share)	0.28	(0.33)
Net loss per share, basic (in dollars per share)	(1.60)	(2.23)
Net loss per share, diluted (in dollars per share)	$ (1.60)	$ (2.23)
Weighted-average shares outstanding, basic (in shares)	44,372,223	26,110,785
Weighted-average shares outstanding, diluted (in shares)	44,372,223	26,110,785
GeneFab Option
Other income (expense)
Change in fair value	$ 3,318	$ 0
GeneFab Note Receivable
Other income (expense)
Change in fair value	626	0
GeneFab Economic Share
Other income (expense)
Change in fair value	$ 16	$ 0

Stockholders’ Equity (Deficit) - Redeemable Convertible Preferred Stock (Details) - USD ($)	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Class of Stock [Line Items]
Shares Authorized (in shares)			19,517,990
Shares Issued (in shares)			19,517,988
Shares Outstanding (in shares)	0	0	19,517,988
Net Carrying Value	$ 0	$ 0	$ 171,833,000
Aggregate Liquidation Preference			$ 163,834,000
Series A
Class of Stock [Line Items]
Issue Price Per Share (in dollars per shares)			$ 1.6427
Shares Authorized (in shares)			6,888,563
Shares Issued (in shares)			6,888,563
Shares Outstanding (in shares)			6,888,563
Net Carrying Value			$ 57,408,000
Aggregate Liquidation Preference			$ 57,822,000
Series B
Class of Stock [Line Items]
Issue Price Per Share (in dollars per shares)			$ 1.6427
Shares Authorized (in shares)			12,629,427
Shares Issued (in shares)			12,629,425
Shares Outstanding (in shares)			12,629,425
Net Carrying Value			$ 114,425,000
Aggregate Liquidation Preference			$ 106,012,000

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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- Definition

Carrying amount, attributable to parent, of an entity's issued and outstanding stock which is not included within permanent equity. Temporary equity is a security with redemption features that are outside the control of the issuer, is not classified as an asset or liability in conformity with GAAP, and is not mandatorily redeemable. Includes any type of security that is redeemable at a fixed or determinable price or on a fixed or determinable date or dates, is redeemable at the option of the holder, or has conditions for redemption which are not solely within the control of the issuer. Includes stock with a put option held by an ESOP and stock redeemable by a holder only in the event of a change in control of the issuer.

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+ Details

Reverse Recapitalization -Schedule of Common Stock Outstanding Immediately Following Consummation of Merger (Details) - shares	Jun. 08, 2022	Dec. 31, 2023	Dec. 31, 2022
Reverse Recapitalization [Line Items]
Issued to PIPE Investors (in shares)	5,060,000
Issued to Legacy Senti stockholders (in shares)	23,163,614
Early exercised shares subject to repurchase (in shares)	(288,807)
Total shares of common stock immediately after Merger (in shares)	43,368,270	45,700,161	44,062,534
Common stock issued upon conversion of redeemable convertible stock (in shares)	19,517,988
Common Class A
Reverse Recapitalization [Line Items]
Issued to Bayer in connection with convertible note cancellation and exchange (in share)	517,500
Common Shareholders
Reverse Recapitalization [Line Items]
Owned by Dynamics’ stockholders (in shares)	14,915,963

Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2023

Fair Value Disclosures [Abstract]

Cash, Cash Equivalents and Investments

The following tables summarize the estimated value of cash equivalents, restricted cash and short-term investments by category (in thousands):


	December 31, 2023
	Amortized Cost		Unrealized Gain		Unrealized Loss		Estimated Fair Value		Cash and cash equivalents		Restricted cash		Short-term investments
Cash	$	4,205	$	—	$	—	$	4,205	$	4,205	$	—	$	—
Level 1
Money market funds	$	35,243	$	—	$	—	$	35,243	$	31,721	$	3,522	$	—
Subtotal	35,243		—		—		35,243		31,721		3,522		—






Total	$	39,448	$	—	$	—	$	39,448	$	35,926	$	3,522	$	—


	December 31, 2022
	Amortized Cost		Unrealized Gain		Unrealized Loss		Estimated Fair Value		Cash and cash equivalents		Restricted cash		Short-term investments

Level 1
Money market funds	$	45,412	$	—	$	—	$	45,412	$	42,046	$	3,366	$	—
Subtotal	45,412		—		—		45,412		42,046		3,366		—
Level 2
U.S. Treasury securities	$	14,866	$	4	$	(3)	$	14,867	$	—	$	—	$	14,867
U.S. agency securities	$	5,938	$	—	$	—	$	5,938	$	3,983	$	—	$	1,955
Commercial paper	$	28,122	$	—	$	—	$	28,122	$	5,994	$	—	$	22,128
Corporate debt securities	$	7,590	$	1	$	(1)	$	7,590	$	5,598	$	—	$	1,992
Subtotal	$	56,516	$	5	$	(4)	$	56,517	$	15,575	$	—	$	40,942
Total	$	101,928	$	5	$	(4)	$	101,929	$	57,621	$	3,366	$	40,942

Summary of Changes in Fair Value of Level 3 Financial Instruments

The following table presents a summary of the changes in the fair value of the Company’s Level 3 financial instruments (in thousands):


	Contingent Earnout Liability
Fair value as of December 31, 2022	$	(227)

Change in fair value included in other income (expense)	207
Fair value as of December 31, 2023	$	(20)

The following table presents a summary of the changes in the fair value of the GeneFab Option (in thousands):


	GeneFab Option
Initial recognition as of August 7, 2023	$	(9,649)

Change in fair value included in other income (expense)	3,318
Fair value as of December 31, 2023	$	(6,331)

Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation

The following table presents a summary of the changes in the fair value of the GeneFab Note Receivable (in thousands):


	Note Receivable
Initial recognition as of August 7, 2023	$	16,614

Change in fair value included in other income (expense)	626
Fair value as of December 31, 2023	$	17,240

The following table presents a summary of the changes in the fair value of the GeneFab Economic Share (in thousands):


	GeneFab Economic Share
Initial recognition as of August 7, 2023	$	1,800

Change in fair value included in other income (expense)	16
Fair value as of December 31, 2023	$	1,816

Fair Value Measurement Inputs and Valuation Techniques

The significant assumptions utilized in the valuation are described below:


	December 31,		August 7
	2023		2023
Current stock price	$	0.66	$	0.90
Expected volatility	98.1%		86.0%
Risk-free interest rate	4.12%		4.44%
Expected term (years)	2.5		3.0

The significant assumptions utilized in the valuation are described below:


	December 31,		August 7
	2023		2023
GeneFab equity value (in thousands)	$	35,448	$	37,314
Volatility	65.8%		54.0%
Risk free rate	3.93%		4.23%
Expected term	4.0		4.5

Reverse Recapitalization (Tables)

12 Months Ended

Dec. 31, 2023

Business Combination and Asset Acquisition [Abstract]

Schedule of common stock outstanding immediately following consummation of merger

The number of shares of the Company’s common stock outstanding immediately following the consummation of the Merger was:


	Shares



Owned by Dynamics’ stockholders	14,915,963
Issued to PIPE Investors	5,060,000
Issued to Bayer in connection with convertible note cancellation and exchange	517,500
Issued to Legacy Senti stockholders	23,163,614	(1)
Early exercised shares subject to repurchase	(288,807)
Total shares of common stock immediately after Merger	43,368,270

________________

(1) Includes 19,517,988 shares of common stock issued upon conversion of Legacy Senti’s redeemable convertible preferred stock.

Consolidated Statements of Operations and Comprehensive Loss (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Research and development expense	$ 32,150	$ 28,145
Related Party
Research and development expense	$ 3,113	$ 0

Stockholders’ Equity (Deficit) - Common Stock Reserved for Future Issuance (Details) - $ / shares	Dec. 31, 2023	Dec. 31, 2022	Jun. 08, 2022
Equity [Abstract]
Common stock, shares authorized (in shares)	500,000,000	500,000,000
Common stock, par or stated value (in dollars per share)	$ 0.0001	$ 0.0001	$ 0.0001
Class of Stock [Line Items]
Common stock reserved for future issuance (in shares)	44,832,169	24,186,271
Series A and B redeemable convertible preferred stock
Class of Stock [Line Items]
Common stock reserved for future issuance (in shares)	0	0
Common Stock Purchase Agreement
Class of Stock [Line Items]
Common stock reserved for future issuance (in shares)	7,327,049	8,327,049
Options
Class of Stock [Line Items]
Common stock reserved for future issuance (in shares)	11,582,938	9,875,675
Restricted Stock Units (RSUs)
Class of Stock [Line Items]
Common stock reserved for future issuance (in shares)	225,282	447,948
Equity Plans
Class of Stock [Line Items]
Common stock reserved for future issuance (in shares)	3,672,276	2,948,472
Employee Stock
Class of Stock [Line Items]
Common stock reserved for future issuance (in shares)	336,320	481,627
Contingent earnout common stock
Class of Stock [Line Items]
Common stock reserved for future issuance (in shares)	2,000,000	2,000,000
GeneFab Option
Class of Stock [Line Items]
Common stock reserved for future issuance (in shares)	19,633,444	0
Unvested early exercised common stock
Class of Stock [Line Items]
Common stock reserved for future issuance (in shares)	54,860	105,500

GeneFab Transaction (Tables)

12 Months Ended

Dec. 31, 2023

Disposal Groups, Including Discontinued Operations

The following table summarizes the major classes of assets and liabilities of the discontinued operations (in thousands):


	December 31,
	2023		2022
Prepaid expenses and other current assets	$	—	$	209
Total current assets of discontinued operations	$	—	$	209

Property and equipment, net	$	—	$	4,775
Other long-term assets	—		10
Total non-current assets of discontinued operations	$	—	$	4,785

Accounts payable	$	—	$	897
Accrued expenses and other current liabilities	243		288
Total current liabilities of discontinued operations	$	243	$	1,185

The following table summarizes the operating results of the discontinued operations (in thousands):


	Years Ended December 31,
	2023		2022
Operating expenses:
Research and development	$	10,003	$	5,922
General and administrative	(496)		2,623
Total operating expenses	9,507		8,545
Loss from discontinued operations	(9,507)		(8,545)
Other income (expense)	(6)		—
Gain on disposal of business	21,861		—
Net income (loss) from discontinued operations	$	12,348	$	(8,545)

The following table summarizes the cash flow information of the discontinued operations (in thousands):


	Years Ended December 31,
	2023		2022
Operating activities (noncash adjustments to net income):
Depreciation	$	185	$	31
Stock-based compensation expense	(2,022)		830
Gain on disposal of business	21,861		—
Investing activities: (1)
Purchases of property and equipment	(4,079)		(1,670)
Supplemental disclosures of noncash investing items:
Purchases of property and equipment in accounts payable and accrued expenses	—		3,135

________________

(1) The total consideration received of $37.8 million is a non-cash investing activity.

- Definition

Tabular disclosure of information related to a disposal group. Includes, but is not limited to, a discontinued operation, disposal classified as held-for-sale or disposed of by means other than sale or disposal of an individually significant component.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-SubTopic 10
-Topic 360
-Publisher FASB
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+ Details

Net Loss Per Share

12 Months Ended

Dec. 31, 2023

Earnings Per Share [Abstract]

Net Loss Per Share


	Years Ended December 31,
	2023		2022
Net loss from continuing operations	$	(83,406)	$	(49,665)
Net income (loss) from discontinued operations	12,348		(8,545)
Net loss	$	(71,058)	$	(58,210)

Weighted-average shares used in computing net loss per share, basic and diluted	44,372,223		26,110,785

Net loss per share from continuing operations, basic and diluted	$	(1.88)	(1.90)
Net income (loss) per share from discontinued operations, basic and diluted	0.28		(0.33)
Net loss per share attributable to common stockholders, basic and diluted	$	(1.60)	$	(2.23)


	Years Ended December 31,
	2023	2022

Stock options to purchase common stock	11,582,938	9,875,675
Unvested early exercised options	54,860	105,500
Restricted stock units outstanding	225,282	447,948
Contingent earnout common stock	2,000,000	2,000,000
GeneFab Option	19,633,444	0
Total	33,496,524	12,429,123

Income Tax

12 Months Ended

Dec. 31, 2023

Income Tax Disclosure [Abstract]

Income Tax

The Company did not record any income tax expense or benefit during the years ended December 31, 2023 and 2022. The Company has a net operating loss and has provided a valuation allowance against net deferred tax assets due to uncertainties regarding the Company’s ability to realize these assets.

For the calendar years ended December 31, 2023 and 2022, the tax effects of significant items comprising the Company's deferred taxes are as follows (in thousands):


	Years Ended December 31,
	2023		2022

Deferred tax assets:
Net operating losses	$	33,566	$	25,249
Capitalized R&D Section 174 expense	10,146		5,131
Tax credits	9,237		6,053
Lease liability	6,005		7,789
Stock-based compensation	4,785		683
Accruals and reserves	724		756
Related Party Fair Value Adjustment	346		—
Fixed asset basis	—		259

Total deferred tax assets	64,809		45,920
Deferred tax liabilities:
Operating lease right-of-use assets	(1,548)		(3,869)
Fixed asset basis	(2,008)		—
Total deferred tax liabilities	(3,556)		(3,869)
Valuation allowance	(61,253)		(42,051)
Net deferred taxes	$	—	$	—

The Company records the tax benefit of net operating losses, temporary differences, and credit carryforwards as assets to the extent that management assesses that realization is "more likely than not." Realization of the future tax benefits is dependent on the Company's ability to generate sufficient taxable income within the carryforward period. Because of the Company's recent history of operating losses, management believes that recognition of the deferred tax assets arising from the above-mentioned future tax benefits is currently not likely to be realized and, accordingly, has provided a valuation allowance.

The valuation allowance increased by approximately $19.2 million and $12.3 million during years ended December 31, 2023 and 2022, respectively, and the Company’s deferred tax assets continue to be fully offset by the valuation allowance as at December 31, 2023. For the years ended December 31, 2023 and 2022, the Company did not record an income tax provision.

Net operating losses and tax credit carryforwards as of December 31, 2023 are as follows (in thousands):


	Amount		Expiration Years

Net operating losses, federal (Post December 31, 2017)	$	132,504	Do Not Expire
Net operating losses, federal (Pre January 1, 2018)	$	3,508	12/31/2036
Net operating losses, state	$	71,637	12/31/2036
Tax credits, federal	$	6,670	12/31/2038
Tax credits, state	$	5,605	Do Not Expire

Utilization of the net operating loss carryforwards may be subject to a substantial annual limitation due to the ownership change limitations provided by the Internal Revenue Code of 1986, as amended, and similar state provisions. This annual limitation may result in the expiration of net operating losses and credits before utilization. The Company has not performed an analysis to determine the limitation of our net operating loss carryforwards.

The effective tax rate of the Company's provision (benefit) for income taxes differs from the federal statutory rate as follows:


	Years Ended December 31,
	2023	2022

Statutory rate	21.00%	21.00%
State tax	3.30%	(0.13)%
Other	(0.86)%	(0.93)%
Tax credits	3.37%	1.21%
Fair value of series B preferred stock tranche obligation	—%	—%
Fair value of contingent earnout liability	1.04%	3.41%
Valuation allowance	(27.84)%	(24.56)%
Total	—%	—%

The Company has elected to include interest and penalties as a component of tax expense. For the years ended December 31, 2023 and 2022, the Company did not recognize accrued interest and penalties related to unrecognized tax benefits. The Company does not anticipate that the amount of existing unrecognized tax benefits will significantly increase or decrease during the next 12 months.

The Company files income tax returns in federal and various state jurisdictions where a filing obligation has been determined. The federal and state income tax returns from inception to December 31, 2023 remain subject to examination.

The Company had $2.1 million of unrecognized tax benefits as of December 31, 2023. No liability related to uncertain tax positions is recorded on the financial statements as all uncertain tax positions are currently recorded as a reduction to the Company’s deferred tax assets, which are subject to a valuation allowance. If recognized, none of the unrecognized tax benefits would affect the effective tax rate. The Company does not anticipate the total amounts of unrecognized tax benefits will significantly increase or decrease in the next 12 months. No positions were settled with tax authorities in 2023 and no positions were reduced as a result of a lapse of applicable statutes of limitations. The Company’s policy is to include interest and penalties related to unrecognized tax benefits within the provision for income taxes, as necessary. The Company did not recognize any accrued interest and penalties related to gross unrecognized tax benefits related to the year ended December 31, 2023. A reconciliation of the Company’s unrecognized tax benefits for the years ended December 31, 2023 and 2022 is as follows (in thousands):


	Years Ended December 31,
	2023		2022

Balance at beginning of the year	$	1,643	$	1,252
Decrease related to prior year tax positions	(243)		(109)
Increase related to current year tax positions	676		500
Balance at end of the year	$	2,076	$	1,643

- Definition

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
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-Name Accounting Standards Codification
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-Paragraph 13
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+ Details

Stock-Based Compensation - Weighted Average Assumptions (Details) - Options	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Expected term (in years)	5 years 10 months 24 days	5 years 9 months 18 days
Expected volatility (in percent)	82.60%	78.80%
Risk-free interest rate (in percent)	3.60%	3.20%
Dividend yield (in percent)	0.00%	0.00%

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Reference 20: http://www.xbrl.org/2003/role/disclosureRef
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Reference 21: http://www.xbrl.org/2003/role/disclosureRef
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Reference 22: http://www.xbrl.org/2003/role/disclosureRef
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Reference 23: http://www.xbrl.org/2003/role/disclosureRef
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Reference 25: http://www.xbrl.org/2003/role/disclosureRef
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Reference 26: http://www.xbrl.org/2003/role/disclosureRef
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Reference 27: http://www.xbrl.org/2003/role/disclosureRef
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Reference 28: http://www.xbrl.org/2003/role/disclosureRef
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+ Details

Stock-Based Compensation - Performance Awards Activity (Details) - Performance Shares - $ / shares			12 Months Ended
	Jun. 08, 2022	Dec. 19, 2021	Dec. 31, 2023	Dec. 31, 2022
Number of Options
Outstanding, beginning of period (in shares)			5,368,501
Granted (in shares)	6,796,074	8,400,892	0	6,796,074
Forfeited (in shares)			(336,990)
Outstanding, end of period (in shares)			5,031,511	5,368,501
Vested and exercisable, end of period (in shares)			2,009,756
Weighted-Average Exercise Price
Outstanding, beginning of period (in dollars per share)			$ 9.92
Granted (in dollars per share)			0
Forfeited (in dollars per share)			9.92
Outstanding, end of period (in dollars per share)			9.92	$ 9.92
Vested and exercisable (in dollars per share)			$ 9.92
Outstanding, end of period, weighted average remaining contractual life (in years)			7 years 6 months	9 years
Vested and exercisable, end of period, weighted average remaining contractual life (in years)			7 years 3 months 18 days

Income Tax - Effective Tax Rate Reconciliation (Details)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Income Tax Disclosure [Abstract]
Statutory rate	21.00%	21.00%
Effective Income Tax Rate Reconciliation, Percent [Abstract]
State tax	3.30%	(0.13%)
Other	(0.86%)	(0.93%)
Tax credits	3.37%	1.21%
Fair value of series B preferred stock tranche obligation	0.00%	0.00%
Fair value of contingent earnout liability	1.04%	3.41%
Valuation allowance	(27.84%)	(24.56%)
Total	0.00%	0.00%

Stock-Based Compensation - Narrative (Details) $ / shares in Units, $ in Thousands			12 Months Ended
	Jun. 08, 2022 shares	Dec. 19, 2021 tranche shares	Dec. 31, 2023 USD ($) $ / shares shares	Dec. 31, 2022 USD ($) $ / shares shares	Aug. 05, 2022 shares
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Weighted average grant date fair value of options granted (in dollars per share) \| $ / shares			$ 1.14	$ 1.47
Aggregate intrinsic value of options exercised \| $			$ 0	$ 300
Cost not yet recognized, options \| $			5,200	8,000
Stock-based compensation expense \| $			9,670	16,392
Discontinued Operations \| Non-Oncology Business
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Stock-based compensation expense from discontinued operations \| $			(2,000)	$ 800
GeneFab
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Stock-based compensation expense \| $			$ (2,000)
2016 Stock Incentive Plan
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Issued in period (in shares) \| shares			0	0
Common stock subject to repurchase (in shares) \| shares			54,860	105,500
Common stock subject to repurchase \| $			$ 100	$ 300
2022 Stock Incentive Plan
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Exercise price of an ISO granted to a stockholder (in percent)			10.00%
Authorized for issuance under share-based payment arrangement (in shares) \| shares	2,492,735		2,419,363
Annual increase in authorized shares, percentage			5.00%
2022 Stock Incentive Plan \| Maximum
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Estimated fair value of the shares on the date of grant (in percent)			110.00%
2022 Inducement Equity Plan
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Authorized for issuance under share-based payment arrangement (in shares) \| shares			1,252,913		2,000,000
Options
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Cost not yet recognized, period for recognition (in years)			2 years 1 month 28 days	2 years 8 months 12 days
Options \| 2016 Stock Incentive Plan
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting period (in years)			4 years
Expiration period (in years)			10 years
Options \| 2022 Stock Incentive Plan
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting period (in years)			4 years
Expiration period (in years)			10 years
Options \| 2022 Inducement Equity Plan
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting period (in years)			4 years
Expiration period (in years)			10 years
Employee Stock
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Authorized for issuance under share-based payment arrangement (in shares) \| shares	592,584		336,320
Percent of outstanding shares	85.00%
offering period (in months)	24 months
ESPP purchase price of common stock, percent of market price (in percent)	1.00%
Performance Shares
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Cost not yet recognized, period for recognition (in years)			1 year 6 months 7 days
Grants in period (in shares) \| shares	6,796,074	8,400,892	0	6,796,074
Terms of award (in years)		four
Exercises during the period (in shares) \| shares			0	0
Cost not yet recognized, excluding options \| $			$ 3,600
Market Awards
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Cost not yet recognized, period for recognition (in years)			7 months 17 days
Grants in period (in shares) \| shares	315,748	605,451	0	315,748
Exercises during the period (in shares) \| shares			0	0
Cost not yet recognized, excluding options \| $			$ 200
Number of tranches \| tranche		4
Award vesting rights (in percent)		25.00%
Restricted Stock Units (RSUs)
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Cost not yet recognized, period for recognition (in years)			8 months 19 days
Cost not yet recognized, excluding options \| $			$ 200

Cover - USD ($) $ in Millions	12 Months Ended
Cover - USD ($) $ in Millions	Dec. 31, 2023	Mar. 18, 2024	Jun. 30, 2023
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2023
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	001-40440
Entity Registrant Name	Senti Biosciences, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	86-2437900
Entity Address, Address Line One	2 Corporate Drive, First Floor
Entity Address, City or Town	South San Francisco
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94080
City Area Code	(650)
Local Phone Number	239-2030
Title of 12(b) Security	Common stock, par value $0.0001 per share
Trading Symbol	SNTI
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	true
ICFR Auditor Attestation Flag	false
Document Financial Statement Error Correction	false
Entity Shell Company	false
Entity Public Float			$ 23.5
Entity Common Stock, Shares Outstanding		45,755,021
Documents Incorporated by Reference	Portions of the registrant’s Definitive Proxy Statement relating to its 2024 Annual Meeting of Stockholders (the “Proxy Statement”), which the registrant intends to file pursuant to Regulation 14A with the Securities and Exchange Commission (the “SEC”) not later than 120 days after the registrant’s fiscal year end of December 31, 2023 or an amendment on Form 10-K/A filed with the SEC within 120 days after the end of the registrant’s fiscal year, are incorporated by reference into Part III of this Annual Report on Form 10-K where indicated.
Entity Central Index Key	0001854270
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	FY
Amendment Flag	false

Summary of Significant Accounting Policies - Schedule of Cash and Cash Equivalents (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Accounting Policies [Abstract]
Cash and cash equivalents	$ 35,926	$ 57,621
Restricted cash	3,522	3,366
Total cash, cash equivalents and restricted cash	$ 39,448	$ 60,987	$ 59,291

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Assets
Cash and cash equivalents	$ 35,926	$ 57,621
Short-term investments	0	40,942
Current assets of discontinued operations	0	209
Total current assets	71,200	102,579
Restricted cash	3,522	3,366
GeneFab receivable - related party, net of current portion	1,119	0
Property and equipment, net	25,338	51,361
Operating lease right-of-use assets	16,274	18,418
GeneFab Economic Share - related party	1,816	0
Other long-term assets	215	283
Noncurrent assets of discontinued operations	0	4,785
Total assets	119,484	180,792
Liabilities and Stockholders’ Equity
Accounts payable	1,250	1,370
Finance lease liabilities, current portion	97	0
Early exercise liability, current portion	135	135
Deferred revenue	0	799
GeneFab sublease deferred income - related party	989	0
Accrued expenses and other current liabilities	5,927	12,576
Operating lease liabilities	4,031	1,988
Current liabilities of discontinued operations	243	1,185
Total current liabilities	12,672	18,053
Operating lease liabilities, net of current portion	33,538	35,103
Contingent earnout liability	20	227
GeneFab Option - related party	6,331	0
Early exercise liability, net of current portion	10	146
Total liabilities	52,571	53,529
Commitments and contingencies (Note 15)
Stockholders’ equity:
Common stock, $0.0001 par value; 500,000,000 shares authorized at December 31, 2023 and December 31, 2022; 45,700,161 and 44,062,534 shares issued and outstanding at December 31, 2023 and December 31, 2022, respectively	5	4
Additional paid-in capital	311,252	300,544
Accumulated other comprehensive income	0	1
Accumulated deficit	(244,344)	(173,286)
Total stockholders’ equity	66,913	127,263
Total liabilities, redeemable convertible preferred stock and stockholders’ equity	119,484	180,792
Nonrelated Party
Assets
Accounts receivable	112	626
Prepaid expenses and other current assets	2,783	3,181
Related Party
Assets
Accounts receivable	17,592	0
Prepaid expenses and other current assets	$ 14,787	$ 0

GeneFab Transaction - Discontinued Operations (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2023	Dec. 31, 2022	Aug. 07, 2023
Disposal Group, Including Discontinued Operation, Balance Sheet Disclosures [Abstract]
Total current assets of discontinued operations	$ 0	$ 209	$ 0	$ 209
Total non-current assets of discontinued operations	0	4,785	0	4,785
Total current liabilities of discontinued operations	243	1,185	243	1,185
Operating expenses:
Net income (loss) from discontinued operations	12,348	(8,545)	12,348	(8,545)
GeneFab
Supplemental disclosures of noncash investing items:
Consideration received in collaborative development agreement					$ 37,800
GeneFab \| Discontinued Operations, Disposed of by Sale \| Non-Oncology Business
Disposal Group, Including Discontinued Operation, Balance Sheet Disclosures [Abstract]
Prepaid expenses and other current assets	0	209	0	209
Total current assets of discontinued operations	0	209	0	209
Property and equipment, net	0	4,775	0	4,775
Other long-term assets	0	10	0	10
Total non-current assets of discontinued operations	0	4,785	0	4,785
Accounts payable	0	897	0	897
Accrued expenses and other current liabilities	243	288	243	288
Total current liabilities of discontinued operations	$ 243	$ 1,185	243	1,185
Operating expenses:
Research and development			10,003	5,922
General and administrative			(496)	2,623
Total operating expenses			9,507	8,545
Loss from discontinued operations			(9,507)	(8,545)
Other income (expense)			(6)	0
Gain on disposal of business			21,861	0
Net income (loss) from discontinued operations			12,348	(8,545)
Cash flows from operating activities
Depreciation			185	31
Stock-based compensation expense			(2,022)	830
Gain on disposal of business			21,861	0
Investing activities:
Purchases of property and equipment			(4,079)	(1,670)
Supplemental disclosures of noncash investing items:
Purchases of property and equipment in accounts payable and accrued expenses			$ 0	$ 3,135

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2023	Dec. 31, 2022	Jun. 08, 2022
Statement of Financial Position [Abstract]
Common stock, par or stated value (in dollars per share)	$ 0.0001	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	500,000,000	500,000,000
Common stock, shares issued (in shares)	45,700,161	44,062,534
Common stock, shares outstanding (in shares)	45,700,161	44,062,534	43,368,270

Stock-Based Compensation - Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation expense	$ 11,692	$ 15,562
General and administrative
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation expense	10,236	13,340
Research and development
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation expense	$ 1,456	$ 2,222

Subsequent Events (Details)	Jan. 05, 2024
Subsequent Event
Subsequent Event [Line Items]
Workforce to be reduced (in percent)	37.00%

Other Financial Statement information - Schedule of Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Related Party Transaction [Line Items]
Prepaid expenses (including prepaid rent)	$ 2,546	$ 1,871
Deposits	42	1,209
Other	195	101
Nonrelated Party
Related Party Transaction [Line Items]
Prepaid expenses and other current assets	$ 2,783	$ 3,181

Stock-Based Compensation - Restricted Stock Units Activity (Details) - Restricted Stock Units (RSUs)	12 Months Ended
	Dec. 31, 2023 $ / shares shares
Number of Restricted Stock Units
Outstanding, beginning of period (in shares) \| shares	447,948
Forfeited (in shares) \| shares	(222,666)
Outstanding, end of period (in shares) \| shares	225,282
Weighted-Average Grant Date Fair Value
Outstanding, beginning of period (in dollars per share) \| $ / shares	$ 2.50
Forfeited (in dollars per share) \| $ / shares	0
Outstanding, end of period (in dollars per share) \| $ / shares	$ 2.50

GeneFab Transaction

12 Months Ended

Dec. 31, 2023

GeneFab Transaction

services are to be provided by each party to the other party during a transition period beginning on the closing of the transaction.

power to direct the significant activities of GeneFab. As a result, the Company determined it is not the primary beneficiary and therefore does not consolidate GeneFab.

Refer to Note 16. Related Parties for GeneFab related party considerations.

Gain on the Disposal of Business

Discontinued Operations

The following table summarizes the major classes of assets and liabilities of the discontinued operations (in thousands):


	December 31,
	2023		2022
Prepaid expenses and other current assets	$	—	$	209
Total current assets of discontinued operations	$	—	$	209

Property and equipment, net	$	—	$	4,775
Other long-term assets	—		10
Total non-current assets of discontinued operations	$	—	$	4,785

Accounts payable	$	—	$	897
Accrued expenses and other current liabilities	243		288
Total current liabilities of discontinued operations	$	243	$	1,185

The following table summarizes the operating results of the discontinued operations (in thousands):


	Years Ended December 31,
	2023		2022
Operating expenses:
Research and development	$	10,003	$	5,922
General and administrative	(496)		2,623
Total operating expenses	9,507		8,545
Loss from discontinued operations	(9,507)		(8,545)
Other income (expense)	(6)		—
Gain on disposal of business	21,861		—
Net income (loss) from discontinued operations	$	12,348	$	(8,545)

The following table summarizes the cash flow information of the discontinued operations (in thousands):


	Years Ended December 31,
	2023		2022
Operating activities (noncash adjustments to net income):
Depreciation	$	185	$	31
Stock-based compensation expense	(2,022)		830
Gain on disposal of business	21,861		—
Investing activities: (1)
Purchases of property and equipment	(4,079)		(1,670)
Supplemental disclosures of noncash investing items:
Purchases of property and equipment in accounts payable and accrued expenses	—		3,135

________________

(1) The total consideration received of $37.8 million is a non-cash investing activity.

Related Parties

NEA

Bayer Healthcare LLC

Bayer held 5,878,488 shares of the Company’s common stock as of December 31, 2023 and 2022. Accordingly, Bayer is considered a related party.

Seer, Inc.

GeneFab, LLC.

Based on the intricacies of the GeneFab Transaction noted above and in Note 4. GeneFab Transaction, we have determined that GeneFab is a related party.

- Definition

+ References

+ Details

Other Financial Statement information - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Property, Plant and Equipment [Line Items]
Loss on impairment of fixed assets	$ 25,962	$ 0
Property and equipment, net	25,338	51,361
Depreciation	3,400	$ 1,400
GeneFab
Property, Plant and Equipment [Line Items]
Loss on impairment of fixed assets	25,700
Property and equipment, net	54,600
Fair value	28,900
GeneFab \| Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, net	$ 20,100

Revenue - Grant Income (Details) - USD ($) $ in Thousands	12 Months Ended
Revenue - Grant Income (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Disaggregation of Revenue [Line Items]
Grant income	$ 583	$ 1,000
Grant income
Disaggregation of Revenue [Line Items]
Grant income			$ 2,000
Period of recognition of grant (in years)			2 years

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References + Details

Convertible Note	12 Months Ended
Convertible Note	Dec. 31, 2023
Debt Disclosure [Abstract]
Convertible Note	Convertible Note On May 19, 2022, in connection with the Merger, Legacy Senti issued $5.2 million in unsecured convertible promissory notes for the purchase price of $5.2 million. The May 2022 Note was due May 2024 and interest accrued at an annual rate of 3.0%. The May 2022 Note was cancellable and exchangeable or convertible under any of the following circumstances: •Automatic conversion upon the closing of the Merger with Dynamics. The outstanding principal under this note shall be cancelled and exchanged automatically into that number of shares of Dynamics common stock as is equal to (a) the entire principal amount under this note divided by (b) $10.00. Upon conversion of this note, any and all accrued interest under this note shall immediately and automatically be cancelled and forgiven. The shares issued upon conversion of this note shall have the same rights and entitlements as the shares issued in connection with the PIPE by Dynamics. •Automatic conversion upon closing of a qualified IPO. The note and any accrued unpaid interest shall be automatically converted into shares of the equity securities issued in the qualified IPO at a conversion price equal to the product of (a) 80%, and (b) the price per share of the Company’s common stock issued to the public in the qualified IPO. •Automatic conversion upon closing of non-qualified financing. The note and any accrued unpaid interest shall be automatically converted into shares of the Company’s equity securities issued in such non-qualified financing at a conversion price per share equal to the product of (a) 80%, and (b) the lowest per-share selling price of the equity securities issued to other investors in the non-qualified financing. •If the note has not been repaid or previously converted, on or after the maturity date, at the election of the holder, the outstanding balance shall either (a) be repaid in cash in an amount equal to the outstanding principal, or (b) be converted into that number of shares of Legacy Senti’s Series B Preferred Stock equal to the outstanding balance divided by the original issuance price of the Series B Preferred Stock. On June 8, 2022, concurrently with the closing of the Merger, the May 2022 Note was automatically cancelled and exchanged for 517,500 shares of Class A Common Stock at a price of $10.00 per share. In accordance with the accounting guidance for an extinguishment of convertible debt instruments with a conversion feature that is separately accounted for as a derivative, the Company determined that the cancellation and exchange should be accounted for as an extinguishment of the May 2022 Note and a gain on extinguishment of $1.3 million was recorded at the closing of the Merger and all accrued interest at the time of the Merger was reversed and recorded to additional paid in capital.

- Definition

The entire disclosure for information about short-term and long-term debt arrangements, which includes amounts of borrowings under each line of credit, note payable, commercial paper issue, bonds indenture, debenture issue, own-share lending arrangements and any other contractual agreement to repay funds, and about the underlying arrangements, rationale for a classification as long-term, including repayment terms, interest rates, collateral provided, restrictions on use of assets and activities, whether or not in compliance with debt covenants, and other matters important to users of the financial statements, such as the effects of refinancing and noncompliance with debt covenants.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (h)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1B

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(c))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480678/235-10-S99-1

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 470
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org//470/tableOfContent

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1B

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (g)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1B

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
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-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (i)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1B

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
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-Name Accounting Standards Codification
-Section 50
-Paragraph 1C
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1C

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
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-Name Accounting Standards Codification
-Section 50
-Paragraph 1C
-Subparagraph (b)
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-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1C

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1C
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1C

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1E
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1E

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1I
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1I

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1I
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1I

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1I
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1I

+ Details

Operating Leases - Maturities of Operating Lease Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Jun. 03, 2021
Lessee, Operating Lease, Liability, Payment, Due [Abstract]
2024	$ 7,254
2025	7,478
2026	7,712
2027	5,769
2028	4,855
Thereafter	19,529
Total undiscounted lease payments	52,597	$ 46,000
Less imputed interest	(15,028)
Total lease liabilities	37,569
Lessor, Operating Lease, Payment to be Received, Fiscal Year Maturity [Abstract]
2024	4,345
2025	4,476
2026	4,610
2027	4,748
2028	4,891
Thereafter	18,295
Total undiscounted sublease payments	$ 41,365

Stockholders’ Equity (Deficit) - Common Stock Purchase Agreement (Details) - Common Stock - Common Stock Purchase Agreement - USD ($) $ in Millions		12 Months Ended
	Aug. 31, 2022	Dec. 31, 2023
Class of Stock [Line Items]
Maximum proceeds purchase agreement	$ 50.0
Term of agreement	36 months
Number of shares issued, threshold (in shares)	8,727,049
Shares issued in transaction, threshold (as a percent)	19.99%
Trading volume available for purchase, threshold (in percent)	20.00%
Purchase price, threshold	$ 3.0
Number of shares issued (in shares)	100,000
Document preparation fees	$ 0.4
Issuance costs	$ 0.7
Aggregate purchase price		$ 1.2
Common Class A
Class of Stock [Line Items]
Number of shares issued (in shares)		1,300,000
Discount rate
Class of Stock [Line Items]
Discount rate (in percent)	3.00%

Summary of Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2023

Accounting Policies [Abstract]

Basis of Presentation

Unless otherwise noted, the Company has retroactively adjusted all common and preferred share and related price information to give effect to the exchange ratio established in the Merger Agreement.

Use of Estimates

Concentration of Credit Risk

Cash and Cash Equivalents

Cash equivalents consist of amounts deposited in money market funds and securities with original maturity dates of three months or less, which are stated at fair value.

Restricted Cash

Short-term Investments

Fair Value Measurements

•Level 1 – Quoted prices in active markets for identical assets or liabilities.

Fair Value Option

Property and Equipment, Net


Asset Classification						Estimated useful Life
Small equipment						2 years
Computer equipment and software						3 years
Laboratory equipment						5-7 years
Furniture and fixtures						5-7 years
Leasehold improvements						Shorter of the lease term and the useful life

When assets are retired or disposed of, any resulting gain or loss is included in net loss. Expenditures for maintenance and repairs are expensed as incurred.

Impairment of Long-Lived Assets

Leases

Revenue Recognition

Contract Revenue

Grant Income

Research and Development

GeneFab Option

Commitments and Contingencies

Contingent Earnout Equity

price milestones, including the current Company common stock price, expected volatility, risk-free rate, expected term and expected dividend yield.

Stock-Based Compensation Expense

The Company recognizes stock-based compensation expense related to purchase rights issued pursuant to its employee stock purchase plan on a straight-line basis over the offering period.

Net Loss Per Share

Income Taxes

Recently Adopted Accounting Standards and Recent Accounting Standards

Recently Adopted Accounting Standards

Recent Accounting Standards

Retirement Plan (Details) - USD ($) $ in Millions	12 Months Ended
Retirement Plan (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Retirement Benefits [Abstract]
Employer matching contributions, percentage of employees' compensation	4.00%
Contributions	$ 0.7	$ 0.6

Organization and Description of Business (Details) - USD ($) $ in Thousands		3 Months Ended		12 Months Ended
	Jun. 08, 2022	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2023	Dec. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Cash acquired through reverse recapitalization	$ 140,700			$ 300,100
Retained earnings (accumulated deficit)		$ (244,344)	$ (173,286)	(244,344)	$ (173,286)
Net loss		71,058	58,210	71,058	58,210
Cash, cash equivalents, and short-term investments		$ 35,900	$ 98,600	$ 35,900	$ 98,600

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(g)(1)(ii))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480678/235-10-S99-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 323
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (c)
-Publisher FASB
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
-Section 50
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482765/220-10-50-6

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
-Section 50
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Reference 6: http://www.xbrl.org/2003/role/disclosureRef
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Reference 7: http://www.xbrl.org/2003/role/disclosureRef
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Reference 8: http://www.xbrl.org/2003/role/disclosureRef
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Reference 9: http://www.xbrl.org/2003/role/disclosureRef
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Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
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Reference 11: http://www.xbrl.org/2003/role/disclosureRef
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Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
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-URI https://asc.fasb.org//1943274/2147483443/250-10-50-4

Reference 13: http://www.xbrl.org/2003/role/exampleRef
-Topic 946
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-Name Accounting Standards Codification
-Section 55
-Paragraph 10
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-URI https://asc.fasb.org//1943274/2147480167/946-830-55-10

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
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-Name Accounting Standards Codification
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-URI https://asc.fasb.org//1943274/2147483581/946-220-45-7

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
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Reference 17: http://www.xbrl.org/2003/role/disclosureRef
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Reference 18: http://www.xbrl.org/2003/role/disclosureRef
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Reference 19: http://www.xbrl.org/2003/role/disclosureRef
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Reference 20: http://www.xbrl.org/2009/role/commonPracticeRef
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Reference 23: http://www.xbrl.org/2003/role/disclosureRef
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Reference 24: http://www.xbrl.org/2003/role/disclosureRef
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Reference 25: http://www.xbrl.org/2003/role/disclosureRef
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Reference 26: http://www.xbrl.org/2003/role/disclosureRef
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Reference 27: http://www.xbrl.org/2003/role/disclosureRef
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Reference 28: http://www.xbrl.org/2003/role/disclosureRef
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Reference 29: http://www.xbrl.org/2003/role/disclosureRef
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Reference 30: http://www.xbrl.org/2003/role/disclosureRef
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Reference 34: http://www.xbrl.org/2003/role/disclosureRef
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-Section 45
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Reference 36: http://www.xbrl.org/2003/role/disclosureRef
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Reference 37: http://www.xbrl.org/2003/role/disclosureRef
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-URI https://asc.fasb.org//1943274/2147483589/942-220-S99-1

+ Details

- Definition

Amount of accumulated undistributed earnings (deficit).

+ References + Details

Net Loss Per Share - Basic and Diluted Net Earnings (loss) Per Common Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2023	Dec. 31, 2022
Earnings Per Share [Abstract]
Net loss from continuing operations	$ (83,406)	$ (49,665)	$ (83,406)	$ (49,665)
Net income (loss) from discontinued operations	12,348	(8,545)	12,348	(8,545)
Net loss	$ (71,058)	$ (58,210)	$ (71,058)	$ (58,210)
Weighted-average shares used in computing net loss per share, basic (in shares)			44,372,223	26,110,785
Weighted-average shares used in computing net loss per share, diluted (in shares)			44,372,223	26,110,785
Net loss per share from continuing operations, diluted (in dollars per share)			$ (1.88)	$ (1.90)
Net loss per share from continuing operations, basic (in dollars per share)			(1.88)	(1.90)
Net income (loss) per share from discontinued operations, diluted (in dollars per share)			0.28	(0.33)
Net income (loss) per share from discontinued operations, basic (in dollars per share)			0.28	(0.33)
Earnings Per Share
Net loss per share attributable to common stockholders, diluted (in shares)			(1.60)	(2.23)
Net loss per share attributable to common stockholders, basic (in shares)			$ (1.60)	$ (2.23)

Fair Value Measurements

12 Months Ended

Dec. 31, 2023

Fair Value Disclosures [Abstract]

Fair Value Measurements

Cash Equivalents, Restricted Cash and Short-term Investments

The following tables summarize the estimated value of cash equivalents, restricted cash and short-term investments by category (in thousands):


	December 31, 2023
	Amortized Cost		Unrealized Gain		Unrealized Loss		Estimated Fair Value		Cash and cash equivalents		Restricted cash		Short-term investments
Cash	$	4,205	$	—	$	—	$	4,205	$	4,205	$	—	$	—
Level 1
Money market funds	$	35,243	$	—	$	—	$	35,243	$	31,721	$	3,522	$	—
Subtotal	35,243		—		—		35,243		31,721		3,522		—






Total	$	39,448	$	—	$	—	$	39,448	$	35,926	$	3,522	$	—


	December 31, 2022
	Amortized Cost		Unrealized Gain		Unrealized Loss		Estimated Fair Value		Cash and cash equivalents		Restricted cash		Short-term investments

Level 1
Money market funds	$	45,412	$	—	$	—	$	45,412	$	42,046	$	3,366	$	—
Subtotal	45,412		—		—		45,412		42,046		3,366		—
Level 2
U.S. Treasury securities	$	14,866	$	4	$	(3)	$	14,867	$	—	$	—	$	14,867
U.S. agency securities	$	5,938	$	—	$	—	$	5,938	$	3,983	$	—	$	1,955
Commercial paper	$	28,122	$	—	$	—	$	28,122	$	5,994	$	—	$	22,128
Corporate debt securities	$	7,590	$	1	$	(1)	$	7,590	$	5,598	$	—	$	1,992
Subtotal	$	56,516	$	5	$	(4)	$	56,517	$	15,575	$	—	$	40,942
Total	$	101,928	$	5	$	(4)	$	101,929	$	57,621	$	3,366	$	40,942

No securities have contractual maturities of longer than one year. There were no transfers between Levels 1, 2, or 3 for any of the periods presented.

Contingent Earnout Liability

The following table presents a summary of the changes in the fair value of the Company’s Level 3 financial instruments (in thousands):


	Contingent Earnout Liability
Fair value as of December 31, 2022	$	(227)

Change in fair value included in other income (expense)	207
Fair value as of December 31, 2023	$	(20)

The fair value of the Contingent Earnout Liability is based on significant unobservable inputs, which represent Level 3 measurements within the fair value hierarchy.

In determining the fair value of the Contingent Earnout Liability, the Company used a Monte Carlo simulation value model using a distribution of potential outcomes. The assumptions utilized in the calculation were based on the achievement of certain stock price milestones, including the current Company common stock price, expected volatility, risk-free rate, expected term and expected dividend yield. Refer to Note 9. Stockholders’ Equity (Deficit), for further details of the Contingent Earnout.

GeneFab Note Receivable

The following table presents a summary of the changes in the fair value of the GeneFab Note Receivable (in thousands):


	Note Receivable
Initial recognition as of August 7, 2023	$	16,614

Change in fair value included in other income (expense)	626
Fair value as of December 31, 2023	$	17,240

The fair value of the GeneFab Note Receivable is based on significant unobservable inputs, which represent Level 3 measurements within the fair value hierarchy. The GeneFab Note Receivable is presented within GeneFab receivable on the consolidated balance sheet.

The Company has elected to account for the GeneFab Note Receivable under the fair value option in ASC 825, with changes in fair value reported as a component of other income (expense) in the consolidated statements of operations and comprehensive loss. The fair value of the GeneFab Note Receivable was determined by discounting future payments under multiple probability-weighted scenarios using the GeneFab’s cost of borrowing, which was estimated at 13.72% as of the initial recognition date, to 12.53% as of December 31, 2023 based on published CCC-rated corporate bond yields.

GeneFab Option

The following table presents a summary of the changes in the fair value of the GeneFab Option (in thousands):


	GeneFab Option
Initial recognition as of August 7, 2023	$	(9,649)

Change in fair value included in other income (expense)	3,318
Fair value as of December 31, 2023	$	(6,331)

The fair value of the GeneFab Option is based on significant unobservable inputs, which represent Level 3 measurements within the fair value hierarchy.

In determining the fair value of the GeneFab Option, the Company used a Black-Scholes option pricing model.

The significant assumptions utilized in the valuation are described below:


	December 31,		August 7
	2023		2023
Current stock price	$	0.66	$	0.90
Expected volatility	98.1%		86.0%
Risk-free interest rate	4.12%		4.44%
Expected term (years)	2.5		3.0

GeneFab Economic Share

The following table presents a summary of the changes in the fair value of the GeneFab Economic Share (in thousands):


	GeneFab Economic Share
Initial recognition as of August 7, 2023	$	1,800

Change in fair value included in other income (expense)	16
Fair value as of December 31, 2023	$	1,816

The fair value of the GeneFab Economic Share is based on significant unobservable inputs, which represent Level 3 measurements within the fair value hierarchy.

The Company has elected to account for the GeneFab Economic Share under the fair value option in ASC 825, with changes in fair value reported as a component of other income (expense) in the consolidated statements of operations and comprehensive loss. In determining the fair value of the GeneFab Economic Share, the Company used the option pricing method, which allocates total estimated enterprise value to various classes of equity using the Backsolve method.

The significant assumptions utilized in the valuation are described below:


	December 31,		August 7
	2023		2023
GeneFab equity value (in thousands)	$	35,448	$	37,314
Volatility	65.8%		54.0%
Risk free rate	3.93%		4.23%
Expected term	4.0		4.5

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Other Financial Statement information

12 Months Ended

Dec. 31, 2023

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Other Financial Statement information

Prepaid Expenses and Other Current Assets

Prepaid expenses and other current assets consisted of the following (in thousands):


	December 31,

	2023		2022
Prepaid expenses (including prepaid rent)	$	2,546	$	1,871
Deposits	42		1,209

Other	195		101
Total prepaid expenses and other current assets	$	2,783	$	3,181

Property and Equipment, Net

Property and equipment, net consisted of the following (in thousands):


	December 31,

	2023		2022
Lab equipment	$	8,186	$	7,855
Leasehold improvements	22,648		1,869
Computer equipment and software	360		374
Furniture and fixtures	326		326
Construction in progress	—		43,892
Property and equipment at cost	31,520		54,316
Less: accumulated depreciation	(6,182)		(2,955)
Property and equipment, net	$	25,338	$	51,361

Buildout of the current good manufacturing practice (cGMP) facility in Alameda was completed in June 2023 and the assets were placed in service.

As a result of the change in the manner in which the Company expects to recover the assets associated with the lease on the Alameda facility (refer to Note 4. GeneFab Transaction), the ROU asset and the related leasehold improvements became a separate asset group for the purposes of long-lived asset impairment assessment as of August 7, 2023. This asset group reassessment triggered a need to perform an impairment analysis. The Company concluded that the asset group was not recoverable, as the carrying value of the asset group was less than the sum of undiscounted net cash flows expected to be generated from the use of the asset group.

The Company tested the asset group for impairment and recognized an impairment loss in the amount of $25.7 million during the year ended December 31, 2023, representing the difference between the carrying value of the asset group of $54.6 million and its estimated fair value of $28.9 million, determined based on the discounted cash flows expected to be generated from the use of the asset group through the sublease. Further, the Company determined that the individual fair value of the ROU asset within the asset group exceeded its carrying value as of the impairment testing date. Accordingly, the Company allocated the entire impairment loss to the leasehold improvements associated with the Alameda lease. The adjusted carrying value of the leasehold improvements of $20.1 million will be amortized under the existing accounting policy under ASC 842, Leases (“ASC 842”) on a straight-line basis over the remaining lease term.

Depreciation totaled $3.4 million and $1.4 million for the years ended December 31, 2023 and 2022, respectively.

Accrued Expenses and Other Current Liabilities

Accrued expenses and other current liabilities consisted of the following (in thousands):


	December 31,

	2023		2022
Accrued professional and service fees related to facility construction	$	—	$	7,342
Accrued professional and service fees other	3,555		3,496
Accrued employee-related expenses	2,363		1,709
Other accrued expenses	9		29
Total accrued expenses and other current liabilities	$	5,927	$	12,576

Retirement Plan	12 Months Ended
Retirement Plan	Dec. 31, 2023
Retirement Benefits [Abstract]
Retirement Plan	Retirement Plan The Company maintains a defined contribution employee retirement plan, or 401(k) plan, for all employees upon their date of hire. The 401(k) plan is intended to qualify as tax-qualified plans under Section 401(k) of the Internal Revenue Code of 1986, as amended. The plan permit employees to contribute, on a pre-tax basis, a portion of their salary up to the Federally mandated limits. The Company matches an employee’s contribution up to 4% of the employee’s compensation. Contributions to the plans by the Company totaled $0.7 million and $0.6 million, respectively, for the years ended December 31, 2023 and 2022.

Fair Value Measurements - Significant Assumptions (Details) - GeneFab - Level 3 $ in Thousands	Dec. 31, 2023 USD ($) $ / shares	Aug. 07, 2023 USD ($) $ / shares
Expected share price volatility
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Contingent consideration receivable, measurement input	0.658	0.540
Risk-free interest rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Contingent consideration receivable, measurement input	0.0393	0.0423
Expected term (years)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Contingent consideration receivable, measurement input	4.0	4.5
Measurement Input, Equity Value
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Contingent consideration receivable, measurement input \| $	35,448	37,314
Equity Option \| Current stock price
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative liability, measurement input \| $ / shares	0.66	0.90
Equity Option \| Expected share price volatility
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative liability, measurement input	0.981	0.860
Equity Option \| Risk-free interest rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative liability, measurement input	0.0412	0.0444
Equity Option \| Expected term (years)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative liability, measurement input	2.5	3.0

Revenue - Contract Revenue (Details) - USD ($)	1 Months Ended			12 Months Ended
Revenue - Contract Revenue (Details) - USD ($)	May 31, 2023	Dec. 31, 2022	Apr. 30, 2021	Dec. 31, 2023	Dec. 31, 2022	Nov. 30, 2023
Disaggregation of Revenue [Line Items]
Revenue recognized during period previously included in deferred revenue				$ 800,000	$ 1,000,000
Spark
Disaggregation of Revenue [Line Items]
Agreement evaluation period			24 months
Spark \| Minimum
Disaggregation of Revenue [Line Items]
Agreement termination advance notice period			90 days
Spark \| Maximum
Disaggregation of Revenue [Line Items]
Agreement termination advance notice period			180 days
Spark \| License
Disaggregation of Revenue [Line Items]
Variable consideration			$ 3,000,000
Extension of term of contract (in months)	2 months	2 months
Contract assets, cumulative catch-up adjustments		$ (700,000)
Consideration received in collaborative development agreement		$ 800,000		$ 0	$ 800,000
Spark \| License \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-05-01
Disaggregation of Revenue [Line Items]
Expected timing of satisfaction			2 years
Celest Therapeutics (Shanghai) Co. Ltd.
Disaggregation of Revenue [Line Items]
Variable consideration						$ 156,000,000

Subsequent Events	12 Months Ended
Subsequent Events	Dec. 31, 2023
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events Reduction in Force On January 5, 2024, the Company announced a reduction of approximately 37% of its workforce in connection with the Company’s plans to streamline its business operations to enable increased focus on SENTI-202 and to continue with the clinical development of its SENTI-301A program through a partnership in China. The Company incurred certain one-time estimated severance and related costs as part of this resource allocation effort. NASDAQ Bid Price Compliance Notice On January 23, 2024, the Company received written notice from the Listing Qualifications Department granting the Company its request to transfer the listing of its common stock from The Nasdaq Global Market tier to The Nasdaq Capital Market tier, effective January 25, 2024. On February 6, 2024, the Listing Qualifications Department granted the Company’s request for a second 180-calendar day period, or until August 5, 2024, to regain compliance with the $1.00 bid price requirement.

Reverse Recapitalization - Narrative (Details)		12 Months Ended
Reverse Recapitalization - Narrative (Details)	Jun. 08, 2022 USD ($) tranche $ / shares shares	Dec. 31, 2023 USD ($) $ / shares	Dec. 31, 2022 USD ($) $ / shares	May 19, 2022 USD ($)
Reverse Recapitalization [Line Items]
Recapitalization exchange ratio	0.1957
Common stock, par or stated value (in dollars per share) \| $ / shares	$ 0.0001	$ 0.0001	$ 0.0001
Maximum contingent earnout (in shares) \| shares	2,000,000
Number of tranches of contingent earnout shares \| tranche	2
Number of contingent earnout shares per tranche (in shares) \| shares	1,000,000
Number of trading days	20 days
Number of consecutive trading days	30 days
Threshold of years for change of control (in years)	3 years
Cash acquired through reverse recapitalization	$ 140,700,000	$ 300,100,000
Transaction costs	23,500,000
Costs incurred by the Company	$ 4,800,000
Unpaid transaction cost assumed in connection with merger			$ 0
Common Class A
Reverse Recapitalization [Line Items]
Conversion of redeemable convertible preferred stock into common stock in connection with the Reverse Recapitalization, net of transaction costs (in shares) \| shares	517,500
Common stock share price (in dollars per share) \| $ / shares	$ 10.00
May 2022 Note
Reverse Recapitalization [Line Items]
Principal amount of unsecured convertible promissory note				$ 5,200,000
Private Placement
Reverse Recapitalization [Line Items]
Price per share (in dollars per share) \| $ / shares	$ 10.00
Aggregate purchase price	$ 50,600,000
Contingent Consideration, Tranche One
Reverse Recapitalization [Line Items]
Closing stock price to trigger contingent earnout shares (in dollars per share) \| $ / shares	$ 15.00
Term (in years)	2 years
Contingent Consideration, Tranche Two
Reverse Recapitalization [Line Items]
Closing stock price to trigger contingent earnout shares (in dollars per share) \| $ / shares	$ 20.00
Term (in years)	3 years
PIPE Investors \| Private Placement
Reverse Recapitalization [Line Items]
Number of shares issued (in shares) \| shares	5,060,000

Income Tax (Tables)

12 Months Ended

Dec. 31, 2023

Income Tax Disclosure [Abstract]

Schedule of Deferred Tax Assets and Liabilities

For the calendar years ended December 31, 2023 and 2022, the tax effects of significant items comprising the Company's deferred taxes are as follows (in thousands):


	Years Ended December 31,
	2023		2022

Deferred tax assets:
Net operating losses	$	33,566	$	25,249
Capitalized R&D Section 174 expense	10,146		5,131
Tax credits	9,237		6,053
Lease liability	6,005		7,789
Stock-based compensation	4,785		683
Accruals and reserves	724		756
Related Party Fair Value Adjustment	346		—
Fixed asset basis	—		259

Total deferred tax assets	64,809		45,920
Deferred tax liabilities:
Operating lease right-of-use assets	(1,548)		(3,869)
Fixed asset basis	(2,008)		—
Total deferred tax liabilities	(3,556)		(3,869)
Valuation allowance	(61,253)		(42,051)
Net deferred taxes	$	—	$	—

Summary of Operating Loss Carryforwards And Tax Credit Carryforwards

Net operating losses and tax credit carryforwards as of December 31, 2023 are as follows (in thousands):


	Amount		Expiration Years

Net operating losses, federal (Post December 31, 2017)	$	132,504	Do Not Expire
Net operating losses, federal (Pre January 1, 2018)	$	3,508	12/31/2036
Net operating losses, state	$	71,637	12/31/2036
Tax credits, federal	$	6,670	12/31/2038
Tax credits, state	$	5,605	Do Not Expire

Schedule of Effective Income Tax Rate Reconciliation

The effective tax rate of the Company's provision (benefit) for income taxes differs from the federal statutory rate as follows:


	Years Ended December 31,
	2023	2022

Statutory rate	21.00%	21.00%
State tax	3.30%	(0.13)%
Other	(0.86)%	(0.93)%
Tax credits	3.37%	1.21%
Fair value of series B preferred stock tranche obligation	—%	—%
Fair value of contingent earnout liability	1.04%	3.41%
Valuation allowance	(27.84)%	(24.56)%
Total	—%	—%

Schedule of Unrecognized Tax Benefits Roll Forward

A reconciliation of the Company’s unrecognized tax benefits for the years ended December 31, 2023 and 2022 is as follows (in thousands):


	Years Ended December 31,
	2023		2022

Balance at beginning of the year	$	1,643	$	1,252
Decrease related to prior year tax positions	(243)		(109)
Increase related to current year tax positions	676		500
Balance at end of the year	$	2,076	$	1,643

Summary of Significant Accounting Policies - Narrative (Details) $ in Thousands		12 Months Ended
	Jun. 08, 2022 tranche shares	Dec. 31, 2023 USD ($) businessActivitiy reportableSegment	Aug. 07, 2023 USD ($)	Dec. 31, 2022 USD ($)
Business Acquisition, Contingent Consideration [Line Items]
Number of business activities \| businessActivitiy		1
Number of reportable segments \| reportableSegment		1
Maximum contingent earnout (in shares) \| shares	2,000,000
Number of tranches of contingent earnout shares \| tranche	2
Number of contingent earnout shares per tranche (in shares) \| shares	1,000,000
GeneFab \| Notes Receivable \| Level 3
Business Acquisition, Contingent Consideration [Line Items]
Fair value of asset \| $		$ 17,240	$ 16,614
Related Party
Business Acquisition, Contingent Consideration [Line Items]
Prepaid expenses and other current assets \| $		$ 14,787		$ 0
Contingent Consideration, Tranche One
Business Acquisition, Contingent Consideration [Line Items]
Earnout period (in years)	2 years
Contingent Consideration, Tranche Two
Business Acquisition, Contingent Consideration [Line Items]
Earnout period (in years)	3 years

Operating Leases

12 Months Ended

Dec. 31, 2023

Leases [Abstract]

Operating Leases

Lessee Accounting

The Company’s operating leases are primarily for its corporate headquarters located in South San Francisco, California (“HQ lease”) and for additional office and laboratory space located in Alameda, California (“Alameda lease”). The corporate headquarters lease has an initial term of eight years expiring in 2027, with an option to renew for an additional eight years unless canceled by either party thereafter. The Alameda lease has an initial term of eleven years expiring in 2032, with an option to renew the lease for up to two additional terms of five years. The exercise of these renewal options is not recognized as part of the ROU assets and lease liabilities, as the Company did not conclude, at the commencement date of the leases, that the exercise of renewal options or termination options was reasonably certain. The Alameda lease provided for a tenant improvement allowance of up to $17.5 million for the costs relating to the design, permitting and construction of the improvements, to be disbursed by the landlord no later than December 31, 2023. The Company was deemed to be the accounting owner of the tenant improvements primarily because the Company is the principal in the construction and design of the assets, is responsible for costs overruns and retains substantially all economic benefits from the leasehold improvements over their economic lives. Accordingly, the tenant improvement allowance was considered an incentive and was deducted from the initial measurement of the ROU asset and lease liability. The Company estimated the timing of tenant improvement reimbursements at the lease commencement date and upon receipt of the cash incentives, the Company recognized the cash received as an increase in the lease liability.

A summary of total lease costs and other information for the period relating to the Company’s operating leases is as follows (in thousands):


	Years Ended December 31,
	2023		2022
Operating lease cost	$	5,277	$	5,300
Short-term lease cost	73		81
Variable lease cost	1,138		730
Total lease cost	$	6,488	$	6,111


	Years Ended December 31,
	2023		2022
Other information:
Operating cash flows net inflows and (outflows) from operating lease	$	(2,922)	$	11,363
ROU assets obtained in exchange for operating lease obligations (including remeasurement of ROU and lease liabilities due to changes in the timing of receipt of lease incentives)	$	(5)	$	231
Weighted-average remaining lease term	7.5 years		8.2 years
Weighted-average discount rate	9.2%		9.1%

For the years ended December 31, 2023 and 2022, the Company received $3.4 million and $14.1 million, respectively, of the $17.5 million tenant improvement allowance. Through December 31, 2023, the Company has received the full $17.5 million tenant improvement allowance inception-to-date.

As of December 31, 2023 and 2022, amounts disclosed for ROU assets obtained in exchange for lease obligations include amounts added to the carrying amount of ROU assets resulting from lease modifications and reassessments.

Maturities of the Company’s lease liabilities as of December 31, 2023, were as follows (in thousands):



2024	$	7,254
2025	7,478
2026	7,712
2027	5,769
2028	4,855
Thereafter	19,529
Total undiscounted lease payments	52,597
Less imputed interest	(15,028)

Total lease liabilities	$	37,569

As of December 31, 2023, we had one letter of credit held with JPMorgan Chase Bank in the amount of approximately $2.9 million and one letter of credit with Silicon Valley Bank, or SVB, in the amount of approximately $0.5 million related to our facility leases.

Lessor Accounting

In connection with the GeneFab transaction, on August 7, 2023, the Company entered into a sublease with GeneFab to sublease the facility included in the Alameda lease, expiring in September 2032. Total sublease income to be earned from this operating lease, in aggregate, will be approximately $44.1 million over the term of the sublease agreement. Sublease income was $2.0 million for the year ended December 31, 2023. Variable sublease income was $0.3 million for the year ended December 31, 2023. The Company records sublease income in other income (expense) in the consolidated statements of operations and comprehensive loss.

Refer to Note 16. Related Parties for GeneFab related party considerations.

Maturities of the Company’s sublease payments from GeneFab as of December 31, 2023, were as follows (in thousands):


2024	$	4,345
2025	4,476
2026	4,610
2027	4,748
2028	4,891
Thereafter	18,295
Total undiscounted sublease payments	$	41,365