0000950170-24-057106 | 10-Q | XBRL Viewer | Sensei Biotherapeutics INC

Print Document

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) (Parenthetical) - $ / shares	Mar. 31, 2024	Dec. 31, 2023
Statement of Financial Position [Abstract]
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	250,000,000	250,000,000
Common stock, shares issued	25,073,958	25,030,188
Common stock, shares outstanding	25,073,958	25,030,188

Commitments and Contingencies

3 Months Ended

Mar. 31, 2024

Commitments and Contingencies Disclosure [Abstract]

COMMITMENTS AND CONTINGENCIES

6. COMMITMENTS AND CONTINGENCIES

Operating Leases

As of March 31, 2024, the Company leases office and laboratory facilities under operating leases, which expire at various dates through 2027. The Company has $678 thousand in letters of credit outstanding as security on certain of these leases. As part of its adoption of ASC 842, the Company recorded operating right-of-use assets and operating lease liabilities for these leases as of January 1, 2022.

The Company entered into an operating sublease agreement on January 18, 2023 (the "Sublease") with respect to part of its existing Boston office and laboratory facilities (the "Head Lease"). The Company accounted for the Head Lease and the Sublease as separate contracts and there was no effect on the right-of-use asset or lease liability associated with the Head Lease. The Sublease has an effective end date of December 31, 2024. The Head Lease rent expense is presented separately from income related to the Sublease and both are reported as components of operating expenses on the condensed consolidated statements of operations and comprehensive loss. The Company recorded $94 thousand of income related to the Sublease for the three months ended March 31, 2024.

Finance Leases

The Company leases research equipment and furniture under finance leases.

The following table contains a summary of the lease costs recognized under ASC 842 pertaining to the Company’s finance and operating leases for the three months ended March 31, 2024 (in thousands):


	Three Months Ended March 31,
	2024
Lease Cost:
Amortization of finance right-of-use assets	$	194
Interest on finance lease liabilities		28
Operating lease cost		462
Variable lease cost		154
Total lease costs		838
Operating Sublease income		(94	)
Total lease costs, net	$	744

The following table contains a summary of other information pertaining to the Company’s finance and operating leases for the three months ended March 31, 2024 (in thousands, except lease term and discount rate):


	Three Months Ended March 31,
	2024
Other Operating Lease Information:
Operating cash flows for operating leases	$	462
Operating cash flows for operating subleases	$	(98	)
Operating cash flows for finance leases	$	28
Financing cash flows from finance leases	$	199

Weighted average remaining lease term
Operating leases	2.5 years
Financing leases	1.8 years

Weighted average discount rate
Operating leases	7.7%
Financing leases	8.3%

The following table presents the maturity of the Company’s operating and finance lease liabilities as of March 31, 2024 (in thousands):


	Operating		Financing
2024	$	1,397	$	675
2025		1,736		757
2026		1,413		107
2027		59		—
Total future minimum lease payments	$	4,605	$	1,539
Less amount representing interest		408		97
Total lease liabilities	$	4,197	$	1,442

License Agreements

In the normal course of business, the Company enters into licensing agreements with various parties to obtain the right to make, use, and sell licensed products currently in development.

Litigation

The Company records estimated losses from loss contingencies, such as a loss arising from a litigation, when it determines that it is probable a liability has been incurred and the amount of loss can be reasonably estimated. Litigation is subject to many factors that are difficult to predict so that there can be no assurance, in the event of a material unfavorable result in one or more claims, the Company will not incur material costs.

Restructuring and Related Charges - Additional Information (Details) - USD ($)	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Restructuring Cost and Reserve [Line Items]
Restructuring and related charges, Description	In December 2022, the Company began implementing a restructuring plan to reduce operating costs primarily associated with a reduction in the Company's workforce (the “Restructuring”).
Implementing restructuring plan	Dec. 30, 2022
Restructuring expenses	$ 0
Research and Development and General and Administrative Expenses
Restructuring Cost and Reserve [Line Items]
Restructuring expenses		$ 200,000

- 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.

+ References + Details

Income Taxes	3 Months Ended
Mar. 31, 2024
Income Tax Disclosure [Abstract]
INCOME TAXES	11. INCOME TAXES The Company recorded no provision for income taxes for the three months ended March 31, 2024 and 2023. Deferred tax assets and deferred tax liabilities are recognized based on temporary differences between the financial reporting and tax bases of assets and liabilities using statutory rates. Management of the Company has evaluated the positive and negative evidence bearing upon the realizability of its deferred tax assets, which are comprised principally of net operating loss carryforwards, equity-based compensation, research and development tax credit carryforwards, and capitalized research and development expenditures. Under the applicable accounting standards, management has considered the Company’s history of losses and concluded that it is more likely than not that the Company will not recognize the benefits of federal and state deferred tax assets. Accordingly, a full valuation allowance has been established against the Company’s otherwise recognizable net deferred tax assets. On August 16, 2022, the IRA was signed into law, which contains certain revisions to the Internal Revenue Code, including a 1% excise tax on the value of net corporate stock repurchases that is effective beginning on January 1, 2023. The excise tax is recorded as an incremental cost in equity on the Company's condensed consolidated balance sheets and was not significant as of March 31, 2024.

Income Taxes

3 Months Ended

Mar. 31, 2024

Income Tax Disclosure [Abstract]

INCOME TAXES

11. INCOME TAXES

The Company recorded no provision for income taxes for the three months ended March 31, 2024 and 2023.

Deferred tax assets and deferred tax liabilities are recognized based on temporary differences between the financial reporting and tax bases of assets and liabilities using statutory rates. Management of the Company has evaluated the positive and negative evidence bearing upon the realizability of its deferred tax assets, which are comprised principally of net operating loss carryforwards, equity-based compensation, research and development tax credit carryforwards, and capitalized research and development expenditures. Under the applicable accounting standards, management has considered the Company’s history of losses and concluded that it is more likely than not that the Company will not recognize the benefits of federal and state deferred tax assets. Accordingly, a full valuation allowance has been established against the Company’s otherwise recognizable net deferred tax assets.

On August 16, 2022, the IRA was signed into law, which contains certain revisions to the Internal Revenue Code, including a 1% excise tax on the value of net corporate stock repurchases that is effective beginning on January 1, 2023. The excise tax is recorded as an incremental cost in equity on the Company's condensed consolidated balance sheets and was not significant as of March 31, 2024.

- 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
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480990/946-20-50-13

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(h)(2))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480678/235-10-S99-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org//740/tableOfContent

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 14
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482685/740-10-50-14

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 21
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482685/740-10-50-21

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 270
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482526/740-270-50-1

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 17
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482685/740-10-50-17

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SAB TOPIC 6.I.5.Q1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479360/740-10-S99-1

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SAB Topic 11.C)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479360/740-10-S99-2

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482603/740-30-50-2

+ Details

Income Taxes - Additional Information (Details) - USD ($)	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Jan. 01, 2023
Income Tax Disclosure [Abstract]
Provision for income taxes	$ 0	$ 0
Excise tax on repurchases			1.00%

- Definition

Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

+ References + Details

Equity (Tables)

3 Months Ended

Mar. 31, 2024

Summary of Common Stock Warrant Activity

The following is a summary of the employee-issued common stock warrant activity during the three months ended March 31, 2024:


	Number of Common Stock Warrants		Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (in years)		Aggregate Intrinsic Value (in thousands)
Outstanding and exercisable at December 31, 2023		56,692	$	6.19		1.16	$	—
Outstanding and exercisable at March 31, 2024		56,692	$	6.19		0.91	$	—

Warrant | Equity and Debt Fundraising Events

Summary of Common Stock Warrant Activity

The following is a summary of the common stock warrant activity for the three months ended March 31, 2024 related to common stock warrants issued in conjunction with equity and debt fundraising events:


	Number of Common Stock Warrants		Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (in years)		Aggregate Intrinsic Value (in thousands)
Outstanding at December 31, 2023		412,262	$	9.81		3.71	$	—
Outstanding at March 31, 2024		412,262	$	9.81		3.46	$	—

Marketable Securities - Summary of Marketable Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Marketable Securities [Line Items]
Fair Value	$ 47,125	$ 52,746
Marketable Securities
Marketable Securities [Line Items]
Amortized Cost	47,262
Unrealized Gains	3
Unrealized Losses	(140)
Fair Value	47,125
Marketable Securities \| Commercial Paper
Marketable Securities [Line Items]
Amortized Cost	12,414
Unrealized Losses	(14)
Fair Value	12,400
Marketable Securities \| Corporate Bonds
Marketable Securities [Line Items]
Amortized Cost	29,848
Unrealized Gains	3
Unrealized Losses	(14)
Fair Value	29,837
Marketable Securities \| U.S. Government Agencies
Marketable Securities [Line Items]
Amortized Cost	5,000
Unrealized Losses	(112)
Fair Value	$ 4,888

Summary of Significant Accounting Policies - Summary of Estimated Useful Lives of Property and Equipment (Details)	Mar. 31, 2024
Office Equipment and Furniture \| Minimum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Estimated useful life (in years)	3 years
Office Equipment and Furniture \| Maximum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Estimated useful life (in years)	7 years
Research Equipment \| Minimum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Estimated useful life (in years)	1 year
Research Equipment \| Maximum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Estimated useful life (in years)	7 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

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 405
-SubTopic 50
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147477123/405-50-65-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 13
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482477/820-10-65-13

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 13
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482477/820-10-65-13

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 5
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479654/326-10-65-5

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 5
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479654/326-10-65-5

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 5
-Subparagraph (b)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479654/326-10-65-5

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 5
-Subparagraph (c)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479654/326-10-65-5

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 20
-Name Accounting Standards Codification
-Section 65
-Paragraph 6
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480528/815-20-65-6

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 20
-Name Accounting Standards Codification
-Section 65
-Paragraph 6
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480528/815-20-65-6

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 20
-Name Accounting Standards Codification
-Section 65
-Paragraph 6
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480528/815-20-65-6

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 20
-Name Accounting Standards Codification
-Section 65
-Paragraph 6
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480528/815-20-65-6

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 20
-Name Accounting Standards Codification
-Section 65
-Paragraph 6
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480528/815-20-65-6

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 20
-Name Accounting Standards Codification
-Section 65
-Paragraph 6
-Subparagraph (h)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480528/815-20-65-6

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 20
-Name Accounting Standards Codification
-Section 65
-Paragraph 6
-Subparagraph (h)(1)(i)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480528/815-20-65-6

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 20
-Name Accounting Standards Codification
-Section 65
-Paragraph 6
-Subparagraph (h)(1)(iii)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480528/815-20-65-6

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 20
-Name Accounting Standards Codification
-Section 65
-Paragraph 6
-Subparagraph (h)(1)(iv)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480528/815-20-65-6

Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 20
-Name Accounting Standards Codification
-Section 65
-Paragraph 6
-Subparagraph (i)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480528/815-20-65-6

Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 20
-Name Accounting Standards Codification
-Section 65
-Paragraph 6
-Subparagraph (i)(3)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480528/815-20-65-6

Reference 19: http://www.xbrl.org/2003/role/disclosureRef
-Topic 832
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483482/832-10-65-1

Reference 20: http://www.xbrl.org/2003/role/disclosureRef
-Topic 832
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483482/832-10-65-1

Reference 21: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 65
-Paragraph 3
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479845/805-20-65-3

Reference 22: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 65
-Paragraph 3
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479845/805-20-65-3

Reference 23: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 65
-Paragraph 3
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479845/805-20-65-3

Reference 24: http://www.xbrl.org/2003/role/disclosureRef
-Topic 842
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 5
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479832/842-10-65-5

Reference 25: http://www.xbrl.org/2003/role/disclosureRef
-Topic 842
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 5
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479832/842-10-65-5

Reference 26: http://www.xbrl.org/2003/role/disclosureRef
-Topic 842
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 5
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479832/842-10-65-5

Reference 27: http://www.xbrl.org/2003/role/disclosureRef
-Topic 842
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 5
-Subparagraph (d)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479832/842-10-65-5

Reference 28: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480175/815-40-65-2

Reference 29: http://www.xbrl.org/2003/role/disclosureRef
-Topic 848
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483550/848-10-65-2

Reference 30: http://www.xbrl.org/2003/role/disclosureRef
-Topic 848
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (a)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483550/848-10-65-2

Reference 31: http://www.xbrl.org/2003/role/disclosureRef
-Topic 848
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (a)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483550/848-10-65-2

Reference 32: http://www.xbrl.org/2003/role/disclosureRef
-Topic 848
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (a)(3)(iii)(01)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483550/848-10-65-2

Reference 33: http://www.xbrl.org/2003/role/disclosureRef
-Topic 848
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (a)(3)(iii)(03)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483550/848-10-65-2

Reference 34: http://www.xbrl.org/2003/role/disclosureRef
-Topic 105
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 6
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479343/105-10-65-6

Reference 35: http://www.xbrl.org/2003/role/disclosureRef
-Topic 105
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 6
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479343/105-10-65-6

Reference 36: http://www.xbrl.org/2003/role/disclosureRef
-Topic 105
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 6
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479343/105-10-65-6

Reference 37: http://www.xbrl.org/2003/role/disclosureRef
-Topic 105
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 6
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479343/105-10-65-6

Reference 38: http://www.xbrl.org/2003/role/disclosureRef
-Topic 105
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 6
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479343/105-10-65-6

Reference 39: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480016/944-40-65-2

Reference 40: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480016/944-40-65-2

Reference 41: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480016/944-40-65-2

Reference 42: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (f)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480016/944-40-65-2

Reference 43: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (f)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480016/944-40-65-2

Reference 44: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (g)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480016/944-40-65-2

Reference 45: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (g)(2)(i)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480016/944-40-65-2

Reference 46: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (g)(2)(ii)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480016/944-40-65-2

Reference 47: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (g)(2)(iii)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480016/944-40-65-2

Reference 48: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (g)(2)(iv)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480016/944-40-65-2

Reference 49: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (h)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480016/944-40-65-2

Reference 50: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (h)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480016/944-40-65-2

Reference 51: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 5
-Subparagraph (SAB Topic 11.M.Q2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480530/250-10-S99-5

Reference 52: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 4
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479654/326-10-65-4

Reference 53: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 4
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479654/326-10-65-4

Reference 54: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 4
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479654/326-10-65-4

Reference 55: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 8
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482615/740-10-65-8

Reference 56: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 8
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482615/740-10-65-8

Reference 57: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 8
-Subparagraph (d)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482615/740-10-65-8

Reference 58: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 8
-Subparagraph (d)(3)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482615/740-10-65-8

Reference 59: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 4
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479654/326-10-65-4

Reference 60: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 4
-Subparagraph (e)(3)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479654/326-10-65-4

Reference 61: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 4
-Subparagraph (e)(4)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479654/326-10-65-4

Reference 62: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 15
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480336/718-10-65-15

Reference 63: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 15
-Subparagraph (f)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480336/718-10-65-15

Reference 64: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 15
-Subparagraph (f)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480336/718-10-65-15

Reference 65: http://www.xbrl.org/2003/role/disclosureRef
-Topic 926
-SubTopic 20
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483194/926-20-65-2

Reference 66: http://www.xbrl.org/2003/role/disclosureRef
-Topic 926
-SubTopic 20
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483194/926-20-65-2

Reference 67: http://www.xbrl.org/2003/role/disclosureRef
-Topic 926
-SubTopic 20
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483194/926-20-65-2

Reference 68: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-3

Reference 69: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (b)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-1

Reference 70: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (b)(3)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-1

Reference 71: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (b)(4)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-1

Reference 72: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (c)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-1

Reference 73: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 15
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482635/260-10-55-15

Reference 74: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483421/250-10-45-6

Reference 75: http://www.xbrl.org/2003/role/disclosureRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 6
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482833/825-10-65-6

Reference 76: http://www.xbrl.org/2003/role/disclosureRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 6
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482833/825-10-65-6

Reference 77: http://www.xbrl.org/2003/role/disclosureRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 6
-Subparagraph (c)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482833/825-10-65-6

Reference 78: http://www.xbrl.org/2003/role/disclosureRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 6
-Subparagraph (c)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482833/825-10-65-6

Reference 79: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (a)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480175/815-40-65-1

Reference 80: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (a)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480175/815-40-65-1

Reference 81: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (a)(3)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480175/815-40-65-1

Reference 82: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (b)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480175/815-40-65-1

Reference 83: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (b)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480175/815-40-65-1

Reference 84: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480175/815-40-65-1

Reference 85: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480175/815-40-65-1

Reference 86: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (e)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480175/815-40-65-1

Reference 87: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (e)(3)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480175/815-40-65-1

Reference 88: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (e)(4)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480175/815-40-65-1

Reference 89: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480175/815-40-65-1

Reference 90: http://www.xbrl.org/2003/role/disclosureRef
-Topic 310
-SubTopic 20
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481925/310-20-65-2

Reference 91: http://www.xbrl.org/2003/role/disclosureRef
-Topic 310
-SubTopic 20
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481925/310-20-65-2

Reference 92: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480424/946-10-50-3

+ Details

Commitments and Contingencies - Additional Information (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2024 USD ($)
Sale Leaseback Transaction [Line Items]
Lease expiration year	2027
Sublease income	$ 94
Letters of credit outstanding amount	678
Office Space
Sale Leaseback Transaction [Line Items]
Sublease income	$ 94

Related-Party Transactions

3 Months Ended

Mar. 31, 2024

RELATED-PARTY TRANSACTIONS

10. RELATED-PARTY TRANSACTIONS

Purchase Agreement - Apeiron Investment Group

On May 23, 2023, the Company entered into the Apeiron Purchase Agreement with the Apeiron Parties, pursuant to which the Company agreed to purchase 4,454,248 shares of the Company’s common stock from certain of the Apeiron Parties for a purchase price of $1.58 per share. The closing of the purchase transaction was completed on June 1, 2023, pursuant to which the Company paid approximately $7.8 million in the aggregate to the Aperion Parties, including $0.75 million for costs related to the negotiation and execution of the Purchase Agreement. Prior to the closing, certain of the Apeiron Parties beneficially owned more than 5% of the Company's outstanding shares of common stock. Following the closing, the Apeiron Parties owned no outstanding shares of the Company’s common stock. The price per share and the transaction were unanimously approved by the independent directors of the Company’s board of directors.

Under the terms of the Apeiron Purchase Agreement, the Apeiron Parties agreed to withdraw their notice of intent to nominate director candidates for election to the Company’s board of directors at the 2023 annual meeting of stockholders. The Apeiron Parties additionally agreed to customary standstill restrictions, including an agreement to not acquire any additional shares of the Company’s voting securities or any of the Company’s indebtedness until the date that is the earlier of (i) four years from the date of the Apeiron Purchase Agreement and (ii) 30 days prior to the nomination deadline for the nomination of director candidates for election to the Company’s board of directors at the Company’s 2027 annual meeting of stockholders

Purchase Agreement - Cambrian BioPharma, Inc.

On July 31, 2023, the Company entered into the Cambrian Purchase Agreement, pursuant to which the Company agreed to repurchase 1,587,302 shares of its common stock from Cambrian, a beneficial owner of more than 5% of the Company’s outstanding shares of common stock, at a purchase price of $1.26 per share and for an aggregate purchase price of approximately $2 million. The transaction closed on August 15, 2023 and the 1,587,302 repurchased shares were retired and cancelled on or about the date of the closing. James Peyer, a director of the Company, is the CEO of Cambrian. The price per share and the transaction were unanimously approved by the independent directors of the Company’s board of directors.

Under the terms of the Cambrian Purchase Agreement, Cambrian agreed to vote, until thirty days prior to the deadline for delivery of notice for the nomination of director candidates for election to the Company’s board of directors at the Company’s 2025 annual meeting of stockholders (the “Effective Period”), all of Cambrian’s shares of the Company’s common stock at all meetings of stockholders, as well as in any consent solicitations of the Company’s stockholders, in accordance with the board’s recommendations. In the event that Institutional Shareholder Services, Inc. and Glass Lewis & Co., LLC recommend otherwise with respect to any Company proposals (other than the election or removal of directors), Cambrian will be permitted to vote in accordance with such recommendations. Under the terms of the Cambrian Purchase Agreement, Cambrian has also agreed to certain standstill restrictions during the Effective Period including, among other things, with respect to nominating persons for election to the board of directors, submitting any stockholder proposal for consideration at any stockholder meeting, soliciting any proxies, and conducting any “withhold” or similar campaign.

- 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
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Publisher FASB
-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
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (d)
-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))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483575/946-220-S99-1

Reference 8: 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)(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

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Operating expenses:
Research and development	$ 4,917	$ 5,204
General and administrative	3,813	5,804
Total operating expenses	8,730	11,008
Loss from operations	(8,730)	(11,008)
Other income (expense):
Interest income	768	969
Interest expense	(28)	(42)
Loss on asset disposal		(105)
Other (expense) income, net	(2)	9
Net loss	$ (7,992)	$ (10,177)
Net loss per common share, basic	$ (0.32)	$ (0.33)
Net loss per common share, diluted	$ (0.32)	$ (0.33)
Weighted-average number of shares used in computing net loss per common share, basic	25,049,111	30,866,087
Weighted-average number of shares used in computing net loss per common share, diluted	25,049,111	30,866,087
Comprehensive loss:
Net loss	$ (7,992)	$ (10,177)
Other comprehensive items:
Unrealized gain on marketable securities	72	181
Total other comprehensive income	72	181
Total comprehensive loss	$ (7,920)	$ (9,996)

Commitments and Contingencies - Summary of Lease Costs Recognized under ASC 842 Pertaining to Finance and Operating Leases (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Lease Cost:
Amortization of finance right-of-use assets	$ 194	$ 197
Interest on finance lease liabilities	28
Operating lease cost	462
Variable lease cost	154
Total lease costs	838
Operating Sublease income	(94)
Total lease costs, net	$ 744

Employee Retirement Plan - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Defined Benefit Plan Disclosure [Line Items]
Company's matching contributions vesting percentage	100.00%
Accrued expense	$ 82	$ 89
Maximum
Defined Benefit Plan Disclosure [Line Items]
Percentage of company matching contributions of employee's base salary	4.00%

Equity

3 Months Ended

Mar. 31, 2024

Equity [Abstract]

EQUITY

7. Equity

Each share of common stock entitles the holder to one vote on all matters submitted to a vote of the Company’s stockholders. Common stockholders are not entitled to receive dividends, unless declared by the board of directors.

Common Stock Warrants


	Number of Common Stock Warrants		Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (in years)		Aggregate Intrinsic Value (in thousands)
Outstanding at December 31, 2023		412,262	$	9.81		3.71	$	—
Outstanding at March 31, 2024		412,262	$	9.81		3.46	$	—

Share Purchase Agreements

On May 23, 2023, the Company entered into a stock purchase agreement with Apeiron Investment Group Ltd., Presight Sensei Co-Invest Fund, L.P., Presight Sensei Co-Invest Management, L.L.C., Christian Angermayer, Apeiron SICAV Ltd. - Presight Capital Fund ONE, and Altarius Asset Management Ltd. (collectively, the “Apeiron Parties”) (the “Apeiron Purchase Agreement”). Pursuant to the Apeiron Purchase Agreement, the Company acquired 4,454,248 shares of its common stock (“Shares”) from the Apeiron Parties at a purchase price of $1.58 per share. The closing of the acquisition (the “Closing”) occurred on June 1, 2023, pursuant to which the Company paid approximately $7.8 million in the aggregate to the Aperion Parties, including $0.75 million for costs related to the negotiation and execution of the Apeiron Purchase Agreement. The acquired Shares were subsequently retired and cancelled.

On July 31, 2023, the Company entered into a stock purchase agreement with Cambrian BioPharma, Inc. and its associates and controlled affiliates (“Cambrian”), pursuant to which the Company agreed to repurchase 1,587,302 shares of its common stock from Cambrian at a price of $1.26 per share and for an aggregate purchase price of approximately $2.0 million. The transaction closed on August 15, 2023 and the 1,587,302 repurchased shares have been retired and cancelled.

On August 16, 2022, the Inflation Reduction Act of 2022 (“IRA”) was signed into law, which contains certain revisions to the Internal Revenue Code, including a 1% excise tax on the value of net corporate stock repurchases that is effective beginning on January 1, 2023. The excise tax is recorded as an incremental cost in equity on the Company's condensed consolidated balance sheets and was not significant as of March 31, 2024.

- Definition

The entire disclosure for equity.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-13

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (h)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-13

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 14
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-14

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

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 505
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481004/946-505-50-6

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480237/815-40-50-6

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480008/505-10-S99-1

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(e)(1))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480678/235-10-S99-1

Reference 10: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 505
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org//505/tableOfContent

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-13

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (g)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-13

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (i)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-13

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 14
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-14

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 14
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-14

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 16
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-16

Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 18
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-18

Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 18
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-18

Reference 19: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 18
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-18

+ Details

Property and Equipment, Net - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Property, Plant and Equipment [Line Items]
Depreciation and amortization expense	$ 137	$ 161

Pay vs Performance Disclosure - USD ($) $ in Thousands	3 Months Ended
Pay vs Performance Disclosure - USD ($) $ in Thousands	Mar. 31, 2024	Mar. 31, 2023
Pay vs Performance Disclosure
Net Income (Loss)	$ (7,992)	$ (10,177)

- 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
-URI https://asc.fasb.org//1943274/2147481687/323-10-50-3

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 28
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482907/825-10-50-28

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

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-3

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (b)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-1

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480175/815-40-65-1

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 8
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-8

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 9
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-9

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 11
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-11

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 11
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-11

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-4

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

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

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(18))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483586/944-220-S99-1

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 22
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-22

Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-07(9))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483575/946-220-S99-1

Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 3
-Subparagraph (SX 210.6-09(1)(d))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483575/946-220-S99-3

Reference 19: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(4)(i))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1A

Reference 20: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(4)(ii))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1A

Reference 21: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(4)(iii)(A))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1A

Reference 22: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(4)(iv))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1A

Reference 23: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(5))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1A

Reference 24: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(4)(i))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1B

Reference 25: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(4)(iii)(A))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1B

Reference 26: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(4)(iii)(B))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1B

Reference 27: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(4)(iv))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1B

Reference 28: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(5))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1B

Reference 29: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 30
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-30

Reference 30: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 32
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-32

Reference 31: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 60B
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482689/260-10-45-60B

Reference 32: http://www.xbrl.org/2003/role/exampleRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 31
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-31

Reference 33: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 32
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-32

Reference 34: http://www.xbrl.org/2003/role/disclosureRef
-Topic 205
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 7
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483499/205-20-50-7

Reference 35: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 230
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 28
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482740/230-10-45-28

Reference 36: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 1A
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482790/220-10-45-1A

Reference 37: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 1B
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482790/220-10-45-1B

Reference 38: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(20))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483621/220-10-S99-2

Reference 39: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 942
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04(22))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483589/942-220-S99-1

+ Details

Stock-Based Compensation - Summary of Stock Option Award Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2024	Dec. 31, 2023
Share-Based Payment Arrangement [Abstract]
Number of Stock Options, Outstanding balance	3,419,306
Number of Stock Options, Granted	1,421,576
Number of Stock Options, Forfeited	(25,518)
Number of Stock Options, Outstanding balance	4,815,364	3,419,306
Number of Stock Options, Options expected to vest	1,860,763
Number of Stock Options, Exercisable	2,954,601
Weighted-Average Exercise Price, Outstanding balance	$ 7.12
Weighted-Average Exercise Price, Granted	0.78
Weighted-Average Exercise Price, Forfeited	11.84
Weighted-Average Exercise Price,Outstanding balance	5.22	$ 7.12
Weighted-Average Exercise Price, Options expected to vest	1.27
Weighted-Average Exercise Price, Exercisable	$ 7.71
Weighted-Average Remaining Contractual Term, Outstanding balance	7 years 9 months 10 days	7 years 3 months 14 days
Weighted-Average Remaining Contractual Term, Options expected to vest	9 years 1 month 9 days
Weighted-Average Remaining Contractual Term, Exercisable	6 years 11 months 8 days
Aggregate Intrinsic Value, Outstanding	$ 423	$ 0
Aggregate Intrinsic Value, Options expected to vest	286
Aggregate Intrinsic Value, Exercisable	$ 137

Summary of Significant Accounting Policies (Policies)

3 Months Ended

Mar. 31, 2024

Accounting Policies [Abstract]

Basis of Presentation and Principles of Consolidation

The Company has prepared the accompanying condensed consolidated financial statements in conformity with generally accepted accounting principles in the United States (“US GAAP”). The condensed consolidated financial statements include those accounts of the Company and its subsidiaries after elimination of all intercompany accounts and transactions. Certain reclassifications have been made to amounts presented in our condensed consolidated statement of cash flows for the three months ended March 31, 2023 to conform to the presentation for the three months ended March 31, 2024.

Unaudited interim financial information

The condensed consolidated financial statements of the Company included herein have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”). Certain information and note disclosures normally included in financial statements prepared in accordance with US GAAP have been condensed or omitted from these condensed consolidated financial statements, as is permitted by such rules and regulations. Accordingly, these condensed consolidated financial statements should be read in conjunction with the financial statements and notes thereto included in the Company’s Annual Report on Form 10-K. The results for any interim period are not necessarily indicative of results for any future period.

Use of Estimates

The preparation of condensed consolidated financial statements in conformity with US GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities at the date of the condensed consolidated financial statements, and the reported amounts of expenses during the reporting periods presented. Estimates are used for, but are not limited to, depreciation of equipment, the Company’s enterprise value, fair value of financial instruments, the Company’s ability to continue as a going concern and contingencies. Actual results may differ from those estimates.

Cash and Cash Equivalents

Cash and cash equivalents

Cash equivalents are highly liquid investments with an original maturity of 90 days or less at the date of purchase and consist of time deposits and investments in money market funds with commercial banks and financial institutions. At March 31, 2024, cash and cash equivalents included cash on deposit at commercial banks and a money market fund that invests in U.S. Government securities.

Marketable Securities

Marketable securities

Investments consist of marketable securities with original maturities greater than 90 days. The Company has classified its investments with maturities beyond one year as short-term, based on their highly liquid nature and because such marketable securities represent the investment of cash that is available for current operations. The Company considers its investment portfolio of marketable securities to be available-for-sale. Accordingly, these investments are recorded at fair value (Level 2). Unrealized gains and losses are reported as the accumulated other comprehensive items in stockholders’ equity. Amortization and accretion of premiums and discounts are recorded in other income (expense). Realized gains or losses on debt securities are included in interest income or interest expense, respectively. If any adjustment to fair value reflects a decline in value of the investment, the Company considers all available evidence to evaluate the extent to which the decline is other than temporary and, if so, marks the investment to market on the Company’s statement of operations and comprehensive loss.

Property and Equipment

Property and equipment are recorded at cost and depreciated or amortized over the estimated useful lives of the assets. Repairs or maintenance costs are expensed as incurred. Depreciation is computed using the straight-line method over the following estimated useful lives:


Office equipment and furniture	3—7 years
Research equipment	1—7 years

Leases

Effective January 1, 2022, the Company adopted Financial Accounting Standards Board (“FASB”) Accounting Standards Update No. 2016-02, Leases (Topic 842) (“ASC 842”) using the modified retrospective method. At lease inception, the Company determines if an arrangement is or contains a lease, and if so, assesses the lease for classification as either an operating or finance lease. A lease is classified as a finance lease if any one of the following criteria are met: (i) the lease transfers ownership of the asset by the end of the lease term, (ii) the lease contains an option to purchase the asset that is reasonably certain to be exercised, (iii) the lease term is for a major part of the remaining useful life of the asset, (iv) the present value of the lease payments equals or exceeds substantially all of the fair value of the asset, or (v) the leased asset is of such a specialized nature that it is expected to have no alternative use to the lessor at the end of the lease. A lease is classified as an operating lease if it does not meet any of these criteria.

Leases with a term greater than one year are recognized on the balance sheet as right-of-use assets and current and non-current lease liabilities, as applicable. Leases with a term of one year or less are expensed as rent in the period incurred. The Company elected not to separate lease and non-lease components for all underlying assets. As most of the Company’s leases do not provide an implicit rate, the Company uses its incremental borrowing rate based on the information available at the commencement date in determining the present value of lease payments. The incremental borrowing rate is determined by using the rate of interest that the Company would pay to borrow on a collateralized basis an amount equal to the lease payments for a similar term and in a similar economic environment. Lease terms include options to extend or terminate the lease when it is reasonably certain that the Company will exercise the options. For leases that existed prior to the adoption of ASC 842, the Company used the remaining lease term to determine the appropriate incremental borrowing rate.

Recently Issued Accounting Standards

In December 2023, the FASB issued ASU 2023-09, "Income Taxes (Topic 740): Improvements to Income Tax Disclosures". ASU 2023-09 is intended to enhance the transparency and decision usefulness of income tax disclosures. The amendments in ASU

2023-09 address investor requests for enhanced income tax information primarily through changes to the rate reconciliation and income taxes paid information. Early adoption is permitted. A public entity should apply the amendments in ASU 2023-09 prospectively to all annual periods beginning after December 15, 2024. The Company is currently evaluating the impact of this standard on the Company's condensed consolidated financial statements and related disclosures.

In November 2023, the FASB issued ASU No. 2023-07, “Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures” (“ASU 2023-07”). ASU 2023-07 requires disclosure of significant segment expenses regularly presented to the Chief Operating Decision Maker ("CODM") and incorporated into each reported segment profit or loss measure. Entities are required to provide both the amount and a detailed description of the composition of other segment items to reconcile them with the segment profit or loss. Furthermore, organizations must disclose the title and position of their CODM. ASU 2023-07 will be effective for fiscal years beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024. Early adoption is permitted and the amendments in this update are required to be applied on a retrospective basis. The Company is currently evaluating the impact of incorporating ASU 2023-07 guidance on the Company's condensed unaudited consolidated financial statements and related disclosures.

Net Loss Per Share (Tables)

3 Months Ended

Mar. 31, 2024

Earnings Per Share [Abstract]

Schedule of Basic and Diluted Net Loss Per Share

Basic and diluted net loss per share attributable to common stockholders is calculated as follows (in thousands, except share and per share amounts):


	Three Months Ended March 31,
	2024			2023
Net loss	$	(7,992	)	$	(10,177	)
Net loss per share—basic and diluted	$	(0.32	)	$	(0.33	)
Weighted-average number of shares used in computing net loss per share—basic and diluted		25,049,111			30,866,087

Potentially Dilutive Securities Excluded from Calculation of Diluted Net Loss Per Share

The following outstanding potentially dilutive securities have been excluded from the calculation of diluted net loss per share, as their effect is anti-dilutive:


	For the Three Months Ended March 31,
	2024		2023
Stock options to purchase common stock		4,815,364		3,742,702
Unvested restricted stock units		161,961		270,162
Warrants issued to employees and contractor to purchase common stock		56,692		56,692
Warrants issued related to convertible notes and other equity agreements		412,262		412,262

Net Loss Per Share

3 Months Ended

Mar. 31, 2024

Earnings Per Share [Abstract]

NET LOSS PER SHARE

12. NET LOSS PER SHARE

Basic and diluted net loss per share attributable to common stockholders is calculated as follows (in thousands, except share and per share amounts):


	Three Months Ended March 31,
	2024			2023
Net loss	$	(7,992	)	$	(10,177	)
Net loss per share—basic and diluted	$	(0.32	)	$	(0.33	)
Weighted-average number of shares used in computing net loss per share—basic and diluted		25,049,111			30,866,087

The following outstanding potentially dilutive securities have been excluded from the calculation of diluted net loss per share, as their effect is anti-dilutive:


	For the Three Months Ended March 31,
	2024		2023
Stock options to purchase common stock		4,815,364		3,742,702
Unvested restricted stock units		161,961		270,162
Warrants issued to employees and contractor to purchase common stock		56,692		56,692
Warrants issued related to convertible notes and other equity agreements		412,262		412,262

Organization and Operations

3 Months Ended

Mar. 31, 2024

Organization, Consolidation and Presentation of Financial Statements [Abstract]

ORGANIZATION AND OPERATIONS

1. ORGANIZATION AND OPERATIONS

Business

Sensei Biotherapeutics, Inc. (the “Company” or “Sensei”) is an immuno-oncology company that was incorporated in 1999 as a Maryland corporation until incorporated in Delaware on December 1, 2017. The Company is focused on the discovery and development of next-generation therapeutics for cancer patients.

Liquidity and capital resources

Since its inception, the Company has devoted substantially all of its resources to advancing development of its portfolio of programs, establishing and protecting its intellectual property, conducting research and development activities, organizing and staffing the Company, business planning, raising capital and providing general and administrative support for these operations. The Company is subject to risks and uncertainties common to early-stage companies in the biotechnology industry including, but not limited to, technical risks associated with the successful research, development and manufacturing of product candidates, development by competitors of new technological innovations, dependence on key personnel, protection of proprietary technology, compliance with government regulations and the ability to secure additional capital to fund operations. Current and future programs will require significant research and development efforts, including extensive preclinical and clinical testing and regulatory approval prior to commercialization. These efforts require significant amounts of additional capital, adequate personnel and infrastructure. Even if the Company’s drug development efforts are successful, it is uncertain when, if ever, the Company will realize significant revenue from product sales.

Since its inception, the Company has incurred substantial losses and had a net loss of $8.0 million for the three months ended March 31, 2024. As of March 31, 2024, the Company had an accumulated deficit of $239.9 million. The Company expects to generate operating losses and negative operating cash flows for the foreseeable future.

The Company expects that its cash, cash equivalents and marketable securities as of March 31, 2024 of $58.1 million will be sufficient to fund its operations for at least the next twelve months from the date of issuance of these financial statements. The Company will need additional financing to support its continuing operations and pursue its growth strategy. Until such time as the Company can generate significant revenue from product sales, if ever, it expects to finance its operations through a combination of equity offerings, debt financings, collaborations, strategic alliances and licensing arrangements. The Company may be unable to raise additional funds or enter into such other agreements when needed on favorable terms or at all. The inability to raise capital as and when needed would have a negative impact on the Company’s financial condition and its ability to pursue its business strategy. The Company will need to generate significant revenue to achieve profitability, and it may never do so.

Stock-Based Compensation

3 Months Ended

Mar. 31, 2024

Share-Based Payment Arrangement [Abstract]

STOCK-BASED COMPENSATION

8. STOCK-BASED COMPENSATION

2018 Equity Incentive Plan

The Company’s 2018 Stock Incentive Plan (the “2018 Plan”) provided for the Company to grant qualified incentive options, nonqualified options, stock grants and other stock-based awards to employees and non-employees to purchase the Company’s common stock. Upon the effectiveness of the 2021 Plan (as defined below), the Company ceased issuing new awards under the 2018 Plan.

2021 Equity Incentive Plan

The Company’s 2021 Equity Incentive Plan (the “2021 Plan”) was approved by the board of directors on January 27, 2021 and the Company’s stockholders on January 28, 2021, and became effective on the execution of the underwriting agreement related to the Company's initial public offering. The 2021 Plan provides for the grant of incentive stock options to employees, including employees of any parent or subsidiary corporations, and for the grant of nonstatutory stock options, stock appreciation rights, restricted stock awards, restricted stock unit awards, performance awards and other forms of stock awards to employees, directors, and consultants, including employees and consultants of the Company’s affiliates. The number of shares initially reserved for issuance under the 2021 Plan was 5,000,000, which began automatically increasing on January 1 of each calendar year, starting on January 1, 2022 through January 1, 2031, in an amount equal to 4.0% of the total number of shares of the Company’s capital stock outstanding on the last day of the calendar month before the date of each automatic increase, or a lesser number of shares determined by the board of directors. In December 2023, the Company's board of directors determined that the automatic increase of available shares for calendar year 2024 would be reduced from 4.0% to 2.0% of the Company's capital stock. As a result, on January 1, 2024 the number of shares available for issuance pursuant to the 2021 Plan increased to 2,999,187 shares. As of March 31, 2024, 1,610,995 shares remained available for issuance pursuant to the 2021 Plan.

2021 Employee Stock Purchase Plan

The 2021 Employee Stock Purchase Plan (the “2021 ESPP”) was approved by the Company’s board of directors on January 27, 2021 and became effective on the execution of the underwriting agreement related to the initial public offering. A total of 333,333 shares of common stock were initially reserved for issuance under the 2021 ESPP, which will automatically increase on January 1 of each calendar year, beginning on January 1, 2022 through January 1, 2031, by an amount equal to 1.0% of the total shares of common stock outstanding on December 31st of the preceding calendar year. The purchase price of the shares under the 2021 ESPP are at 85% of the lower of the fair market value of the Company’s common stock on the first trading day of the offering period or on the purchase date. As of March 31, 2024, the Company had issued 152,432 shares under the 2021 ESPP. As of March 31, 2024, 1,044,933 shares were available to be issued under the 2021 ESPP. The Company recognized no share-based compensation expense related to the ESPP for the three months ended March 31, 2024.

Stock Options

During 2023, the Company has granted options to purchase shares of common stock to employees and non-employee directors pursuant to the 2021 Plan at a weighted average fair value of $0.59 per share. The Company uses the Black-Scholes option-pricing model to estimate the fair value of the stock options on the applicable grant dates.

The following is a summary of the stock option award activity during the three months ended March 31, 2024:


	Number of Stock Options			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (in years)		Aggregate Intrinsic Value (in thousands)
Outstanding at December 31, 2023		3,419,306		$	7.12		7.29	$	—
Granted		1,421,576		$	0.78
Forfeited		(25,518	)	$	11.84
Outstanding at March 31, 2024		4,815,364		$	5.22		7.78	$	423
Options expected to vest as of March 31, 2024		1,860,763		$	1.27		9.11	$	286
Exercisable at March 31, 2024		2,954,601		$	7.71		6.94	$	137

The aggregate intrinsic value of the outstanding stock option awards is calculated as the difference between the exercise price and the market price of the Company’s common stock at March 31, 2024. There were no stock options exercised in the three months ended March 31, 2024.

The grant date fair value of options vested during the three months ended March 31, 2024 and 2023 was $1.2 million and $1.4 million, respectively.

At March 31, 2024, there was $3.8 million of unrecognized stock-based compensation expense associated with the stock options, which is expected to be recognized over a weighted-average period of 1.71 years.

Restricted Stock Units

The Company has granted restricted stock units with service-based vesting conditions.

The following is a summary of the restricted stock unit activity during the three months ended March 31, 2024:


	Restricted Stock Units			Weighted- Average Grant Date Fair Value
Unvested at December 31, 2023		232,958		$	2.53
Vested		(63,131	)	$	2.91
Forfeited		(7,866	)	$	2.55
Unvested at March 31, 2024		161,961		$	2.38

Pursuant to the 2021 Plan, the Company has historically granted restricted stock units which vest annually over a period of one, two, three or four years. The Company granted no restricted stock units during the three months ended March 31, 2024.

At March 31, 2024, there was approximately $0.3 million of unrecognized stock-based compensation expense associated with the restricted stock units which is expected to be recognized over a weighted-average period of 2.1 years.

Common Stock Warrants

The following is a summary of the employee-issued common stock warrant activity during the three months ended March 31, 2024:


	Number of Common Stock Warrants		Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (in years)		Aggregate Intrinsic Value (in thousands)
Outstanding and exercisable at December 31, 2023		56,692	$	6.19		1.16	$	—
Outstanding and exercisable at March 31, 2024		56,692	$	6.19		0.91	$	—

As of March 31, 2024 there was no unrecognized stock-based compensation expense associated with the common stock warrants.

For the three months ended March 31, 2024, the Company utilized the Black-Scholes option-pricing model for estimating the fair value of the stock options granted. The following table presents the assumptions and the Company’s methodology for developing each of the assumptions used:


	Three Months Ended March 31,
	2024	2023
Volatility	91%-93%	93.0%
Expected term (years)	5.0-6.0	6.0-7.0
Risk-free interest rate	3.9%–4.2%	3.6%-4.0%
Dividend rate	—%	—%

•

Volatility—The Company estimates the expected volatility of its common stock at the date of grant based on the historical volatility of comparable public companies over the expected term.

•

Expected life—The expected life is estimated as the contractual term.

•

Risk-free interest rate—The risk-free rate for periods within the estimated life of the stock award is based on the U.S. Treasury yield curve in effect at the time of grant.

•

Dividend rate—The assumed dividend yield is based upon the Company’s expectation of not paying dividends in the foreseeable future.

Stock-based compensation expense was recorded in the following line items in the condensed consolidated statements of operations for the three months ended March 31, 2024 and 2023 (in thousands):


	Three Months Ended March 31,
	2024		2023
Research and development	$	339	$	292
General and administrative		877		921
Total stock-based compensation expense	$	1,216	$	1,213

Summary of Significant Accounting Policies (Tables)

3 Months Ended

Mar. 31, 2024

Property, Plant and Equipment [Abstract]

Summary of Estimated Useful Lives of Property and Equipment

Depreciation is computed using the straight-line method over the following estimated useful lives:


Office equipment and furniture	3—7 years
Research equipment	1—7 years

Net Loss Per Share - Schedule of Basic and Diluted Net Loss Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Earnings Per Share [Abstract]
Net Income (Loss)	$ (7,992)	$ (10,177)
Net loss per share-basic	$ (0.32)	$ (0.33)
Net loss per share-diluted	$ (0.32)	$ (0.33)
Weighted-average number of shares used in computing net loss per common share, basic	25,049,111	30,866,087
Weighted-average number of shares used in computing net loss per common share, diluted	25,049,111	30,866,087

- Definition

The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-3

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 15
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482635/260-10-55-15

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (e)(4)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480175/815-40-65-1

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480175/815-40-65-1

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 11
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-11

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 11
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-11

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 7
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-7

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482689/260-10-45-2

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 60B
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482689/260-10-45-60B

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-4

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482662/260-10-50-1

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 10
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482689/260-10-45-10

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(25))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483621/220-10-S99-2

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04(27))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483589/942-220-S99-1

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(23))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483586/944-220-S99-1

Reference 16: http://www.xbrl.org/2003/role/exampleRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 52
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482635/260-10-55-52

Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 7
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482689/260-10-45-7

+ Details

- Definition

The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-3

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 15
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482635/260-10-55-15

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (e)(4)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480175/815-40-65-1

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480175/815-40-65-1

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 11
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-11

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 11
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-11

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 7
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-7

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482689/260-10-45-2

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 60B
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482689/260-10-45-60B

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-4

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482662/260-10-50-1

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(25))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483621/220-10-S99-2

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04(27))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483589/942-220-S99-1

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(23))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483586/944-220-S99-1

Reference 15: http://www.xbrl.org/2003/role/exampleRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 52
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482635/260-10-55-52

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 7
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482689/260-10-45-7

+ Details

- Definition

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

+ References

+ Details

Property and Equipment, Net

3 Months Ended

Mar. 31, 2024

Property, Plant and Equipment [Abstract]

PROPERTY AND EQUIPMENT, NET

4. PROPERTY AND EQUIPMENT, NET

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


	March 31, 2024			December 31, 2023
Research equipment	$	2,144		$	2,107
Office equipment and furniture		532			532
Leasehold improvement		253			253
Total property and equipment		2,929			2,892
Less accumulated depreciation and amortization		(1,864	)		(1,727	)
Property and equipment, net	$	1,065		$	1,165

Depreciation and amortization expense for the three months ended March 31, 2024 and 2023 was $137 thousand and $161 thousand, respectively.

Equity - Summary of Common Stock Warrant activity (Details) - Warrant - Equity and Debt Fundraising Events - $ / shares	3 Months Ended	12 Months Ended
	Mar. 31, 2024	Dec. 31, 2023
Class Of Stock [Line Items]
Number of Common Stock Warrants Outstanding, Beginning Balance	412,262
Number of Common Stock Warrants Outstanding, Ending Balance	412,262	412,262
Weighted-Average Exercise Price Outstanding, Beginning Balance	$ 9.81
Weighted-Average Exercise Price Outstanding, Ending Balance	$ 9.81	$ 9.81
Weighted-Average Remaining Contractual Term, Outstanding	3 years 5 months 15 days	3 years 8 months 15 days

- 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/exampleRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-13

Reference 2: http://www.xbrl.org/2003/role/recommendedDisclosureRef
-Topic 272
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483014/272-10-45-3

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 272
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482987/272-10-50-1

Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(d))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480678/235-10-S99-1

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-13

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-13

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-13

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (h)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-13

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 14
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-14

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 18
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-18

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(27)(b))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(28))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-2

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 3
-Subparagraph (SX 210.6-03(i)(2))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479886/946-10-S99-3

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 3
-Subparagraph (SX 210.6-03(i)(1))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479886/946-10-S99-3

Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 3
-Subparagraph (SX 210.6-03(i)(2)(i))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479886/946-10-S99-3

Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 3
-Subparagraph (SX 210.6-03(i)(2)(ii))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479886/946-10-S99-3

+ Details

Net Loss Per Share - Potentially Dilutive Securities Excluded from Calculation of Diluted Net Loss Per Share (Details) - shares	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Employee Stock Option
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potentially dilutive securities excluded from calculation of diluted net loss per share	4,815,364	3,742,702
Unvested Restricted Stock Units
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potentially dilutive securities excluded from calculation of diluted net loss per share	161,961	270,162
Warrants Issued to Employees and Contractor to Purchase Common Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potentially dilutive securities excluded from calculation of diluted net loss per share	56,692	56,692
Warrants Issued Related to Convertible Notes and Other Equity Agreements
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potentially dilutive securities excluded from calculation of diluted net loss per share	412,262	412,262

Fair Value Measurements - Schedule of Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - Fair Value of Recurring $ in Thousands	Mar. 31, 2024 USD ($)
Assets:
Total	$ 57,304
Level 1
Assets:
Total	10,179
Level 2
Assets:
Total	47,125
Money Market Funds
Assets:
Cash equivalents fair value disclosure	10,179
Money Market Funds \| Level 1
Assets:
Cash equivalents fair value disclosure	10,179
Commercial Paper
Assets:
Investments fair value disclosure	12,400
Commercial Paper \| Level 2
Assets:
Investments fair value disclosure	12,400
Corporate Bonds
Assets:
Investments fair value disclosure	29,837
Corporate Bonds \| Level 2
Assets:
Investments fair value disclosure	29,837
U.S. Government Agencies
Assets:
Investments fair value disclosure	4,888
U.S. Government Agencies \| Level 2
Assets:
Investments fair value disclosure	$ 4,888

Stock-Based Compensation - Additional Information (Details) - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023	Jan. 01, 2024	Jan. 01, 2022	Jan. 27, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Recognized share-based compensation expense	$ 1,216,000	$ 1,213,000
Weighted average fair value per share of options granted			$ 0.59
Grant date fair value of options vested	1,200,000	$ 1,400,000
Unrecognized stock-based compensation expense	$ 3,800,000
Weighted-average period	1 year 8 months 15 days
Common Stock Warrants
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized stock-based compensation expense	$ 0
Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted-average period	2 years 1 month 6 days
Unrecognized stock-based compensation expense	$ 300,000
2021 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares reserved for issuance	1,610,995			2,999,187	5,000,000
Number of capital stock outstanding percentage	4.00%
2021 Equity Incentive Plan \| Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage of increase of available shares			4.00%
2021 Equity Incentive Plan \| Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage of increase of available shares			2.00%
2021 Equity Incentive Plan \| Restricted Stock Units \| Vesting Period One
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period	1 year
2021 Equity Incentive Plan \| Restricted Stock Units \| Vesting Period Two
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period	2 years
2021 Equity Incentive Plan \| Restricted Stock Units \| Vesting Period Three
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period	3 years
2021 Equity Incentive Plan \| Restricted Stock Units \| Vesting Period Four
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period	4 years
2021 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares reserved for issuance	1,044,933					333,333
Percentage of number of shares of capital stock outstanding on last day of preceding year	1.00%
Recognized share-based compensation expense	$ 0
Purchase price of fair value common stock, percent	85.00%
Stock issued under plan	152,432

Stock-Based Compensation (Tables)

3 Months Ended

Mar. 31, 2024

Share-Based Payment Arrangement [Abstract]

Summary of Stock Option Award Activity

The following is a summary of the stock option award activity during the three months ended March 31, 2024:


	Number of Stock Options			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (in years)		Aggregate Intrinsic Value (in thousands)
Outstanding at December 31, 2023		3,419,306		$	7.12		7.29	$	—
Granted		1,421,576		$	0.78
Forfeited		(25,518	)	$	11.84
Outstanding at March 31, 2024		4,815,364		$	5.22		7.78	$	423
Options expected to vest as of March 31, 2024		1,860,763		$	1.27		9.11	$	286
Exercisable at March 31, 2024		2,954,601		$	7.71		6.94	$	137

Summary of Restricted Stock Unit Activity

The following is a summary of the restricted stock unit activity during the three months ended March 31, 2024:


	Restricted Stock Units			Weighted- Average Grant Date Fair Value
Unvested at December 31, 2023		232,958		$	2.53
Vested		(63,131	)	$	2.91
Forfeited		(7,866	)	$	2.55
Unvested at March 31, 2024		161,961		$	2.38

Summary of Common Stock Warrant Activity

The following is a summary of the employee-issued common stock warrant activity during the three months ended March 31, 2024:


	Number of Common Stock Warrants		Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (in years)		Aggregate Intrinsic Value (in thousands)
Outstanding and exercisable at December 31, 2023		56,692	$	6.19		1.16	$	—
Outstanding and exercisable at March 31, 2024		56,692	$	6.19		0.91	$	—

Summary of Fair Value Assumptions and Methodology

The following table presents the assumptions and the Company’s methodology for developing each of the assumptions used:


	Three Months Ended March 31,
	2024	2023
Volatility	91%-93%	93.0%
Expected term (years)	5.0-6.0	6.0-7.0
Risk-free interest rate	3.9%–4.2%	3.6%-4.0%
Dividend rate	—%	—%

Summary of Stock-Based Compensation Expense

Stock-based compensation expense was recorded in the following line items in the condensed consolidated statements of operations for the three months ended March 31, 2024 and 2023 (in thousands):


	Three Months Ended March 31,
	2024		2023
Research and development	$	339	$	292
General and administrative		877		921
Total stock-based compensation expense	$	1,216	$	1,213

Marketable Securities (Tables)

3 Months Ended

Mar. 31, 2024

Investments, Debt and Equity Securities [Abstract]

Summary of Marketable Securities

Marketable securities consist of the following as of March 31, 2024 (in thousands):


	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
Commercial paper	$	12,414	$	—	$	(14	)	$	12,400
Corporate bonds		29,848		3		(14	)		29,837
U.S. Government agencies		5,000		—		(112	)		4,888
Total	$	47,262		3	$	(140	)	$	47,125

Restructuring and Related Charges

3 Months Ended

Mar. 31, 2024

Restructuring and Related Activities [Abstract]

RESTRUCTURING AND RELATED CHARGES

13. RESTRUCTURING AND RELATED CHARGES

In December 2022, the Company began implementing a restructuring plan to reduce operating costs primarily associated with a reduction in the Company's workforce (the “Restructuring”).

In connection with the Restructuring, the Company incurred no expenses during the three months ended March 31, 2024.

The Company incurred $0.2 million of expenses within research and development and general and administrative expenses during the three months ended March 31, 2023. These costs primarily related to one-time termination benefits and ongoing benefit arrangements, both of which included severance payments and extended benefits coverage support. These costs were accrued as a liability in December 2022 and settled during the three months ended March 31, 2023. Aggregate costs in connection with the Restructuring also included certain contract termination costs.

Fair Value Measurements

3 Months Ended

Mar. 31, 2024

Fair Value Disclosures [Abstract]

FAIR VALUE MEASUREMENTS

5. FAIR VALUE MEASUREMENTS

The following tables present information about the Company’s financial assets and liabilities measured at fair value on a recurring basis and indicate the level of the fair value hierarchy used to determine such fair values (in thousands):


	Fair value measurements at March 31, 2024
	Level 1		Level 2		Level 3		Total
Assets:
Cash equivalents
Money market funds	$	10,179	$	—	$	—	$	10,179
Investments:
Commercial paper		—		12,400		—		12,400
Corporate bonds		—		29,837		—		29,837
U.S. Government agencies		—		4,888		—		4,888
Total	$	10,179	$	47,125	$	—	$	57,304

When developing fair value estimates, the Company maximizes the use of observable inputs and minimizes the use of unobservable inputs. When available, the Company uses quoted market prices to measure fair value. The valuation technique used to measure fair value for the Company's Level 1 and Level 2 assets is a market approach, using prices and other relevant information generated by market transactions involving identical or comparable assets. If market prices are not available, the fair value measurement is based on models that use primarily market-based parameters including yield curves, volatilities, credit ratings and currency rates. In certain cases where market rate assumptions are not available, the Company is required to make judgments about assumptions market participants would use to estimate the fair value of a financial instrument.

There were no transfers among Level 1, Level 2 or Level 3 categories in the three months ended March 31, 2024 and 2023.

- 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

Commitments and Contingencies - Summary of Other Information Pertaining to Finance and Operating Leases (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Other Operating Lease Information:
Operating cash flows for operating leases	$ 462
Operating cash flows for operating subleases	(98)
Operating cash flows for finance leases	28
Financing cash flows from finance leases	$ 199	$ 186
Weighted average remaining lease term
Operating leases	2 years 6 months
Financing leases	1 year 9 months 18 days
Weighted average discount rate
Operating leases	7.70%
Financing leases	8.30%

Summary of Significant Accounting Policies - Additional Information (Details) - ASU 2016-02	Mar. 31, 2024
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Change in accounting principle, accounting standards update, adopted	true
Change in accounting principle, accounting standards update, adoption date	Jan. 01, 2022

- Definition

Indicates (true false) whether accounting standards update was adopted.

+ References

+ Details

- Definition

Date accounting standards update was adopted, in YYYY-MM-DD format.

+ References

+ Details

- 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

Insider Trading Arrangements	3 Months Ended
Insider Trading Arrangements	Mar. 31, 2024
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false

Marketable Securities

3 Months Ended

Mar. 31, 2024

Investments, Debt and Equity Securities [Abstract]

MARKETABLE SECURITIES

3. MARKETABLE SECURITIES

Marketable securities consist of the following as of March 31, 2024 (in thousands):


	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
Commercial paper	$	12,414	$	—	$	(14	)	$	12,400
Corporate bonds		29,848		3		(14	)		29,837
U.S. Government agencies		5,000		—		(112	)		4,888
Total	$	47,262		3	$	(140	)	$	47,125

As of March 31, 2024, all marketable securities held by the Company had remaining contractual maturities of one year or less.

As of March 31, 2024, $0.1 million of unrealized losses were associated with marketable securities with contractual maturities of one year or less.

There were no impairments of the Company’s assets measured and carried at fair value during the three months ended March 31, 2024.

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Operating activities
Net loss	$ (7,992)	$ (10,177)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	1,216	1,213
Depreciation and amortization	137	161
Accretion on marketable securities	(114)	(348)
Non-cash lease expense	370	316
Amortization of financing lease right-of-use assets	194	197
Loss on fixed asset disposition, net		96
Changes in operating assets and liabilities:
Prepaid expenses	(716)	(1,580)
Other assets	56	(8)
Accounts payable and accrued liabilities	306	242
Compensation and employee benefits	(703)	(1,577)
Operating lease liabilities	(371)	(307)
Other liabilities	1	36
Net cash used in operating activities	(7,616)	(11,736)
Investing activities
Purchases of property and equipment	(37)	(151)
Purchases of short-term investments	(6,259)	(9,846)
Maturities of short-term investments	12,066	12,300
Proceeds from sale of property and equipment		9
Net cash provided by investing activities	5,770	2,312
Financing activities
Principal payments for financing leases	(199)	(186)
Payment of employee restricted stock tax withholdings	(10)	(76)
Net cash used in financing activities	(209)	(262)
Net decrease in cash and cash equivalents	(2,055)	(9,686)
Cash and cash equivalents at beginning of period	13,011	17,795
Cash and cash equivalents at end of period	10,956	8,109
Supplemental disclosure of noncash financing information:
Issuance of equity in exchange for compensation included in compensation and employee benefits	293	302
Property and equipment disposals included in other assets		(120)
Initial measurement of operating lease right-of-use assets		258
Initial measurement of operating lease liabilities		$ 258
Initial measurement of finance lease right-of-use assets	$ 1

Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2024

Fair Value Disclosures [Abstract]

Schedule of Financial Assets and Liabilities Measured at Fair Value on Recurring Basis


	Fair value measurements at March 31, 2024
	Level 1		Level 2		Level 3		Total
Assets:
Cash equivalents
Money market funds	$	10,179	$	—	$	—	$	10,179
Investments:
Commercial paper		—		12,400		—		12,400
Corporate bonds		—		29,837		—		29,837
U.S. Government agencies		—		4,888		—		4,888
Total	$	10,179	$	47,125	$	—	$	57,304

Commitments and Contingencies (Tables)

3 Months Ended

Mar. 31, 2024

Commitments and Contingencies Disclosure [Abstract]

Summary of Lease Costs Recognized under ASC 842 Pertaining to Finance and Operating Leases

The following table contains a summary of the lease costs recognized under ASC 842 pertaining to the Company’s finance and operating leases for the three months ended March 31, 2024 (in thousands):


	Three Months Ended March 31,
	2024
Lease Cost:
Amortization of finance right-of-use assets	$	194
Interest on finance lease liabilities		28
Operating lease cost		462
Variable lease cost		154
Total lease costs		838
Operating Sublease income		(94	)
Total lease costs, net	$	744

Summary of Other Information Pertaining to Finance and Operating Leases


	Three Months Ended March 31,
	2024
Other Operating Lease Information:
Operating cash flows for operating leases	$	462
Operating cash flows for operating subleases	$	(98	)
Operating cash flows for finance leases	$	28
Financing cash flows from finance leases	$	199

Weighted average remaining lease term
Operating leases	2.5 years
Financing leases	1.8 years

Weighted average discount rate
Operating leases	7.7%
Financing leases	8.3%

Summary of Maturity of Operating and Finance Lease Liabilities

The following table presents the maturity of the Company’s operating and finance lease liabilities as of March 31, 2024 (in thousands):


	Operating		Financing
2024	$	1,397	$	675
2025		1,736		757
2026		1,413		107
2027		59		—
Total future minimum lease payments	$	4,605	$	1,539
Less amount representing interest		408		97
Total lease liabilities	$	4,197	$	1,442

Property and Equipment, Net - Summary of Property and Equipment, Net (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Property Plant And Equipment [Line Items]
Total property and equipment	$ 2,929	$ 2,892
Less accumulated depreciation and amortization	(1,864)	(1,727)
Property and equipment, net	1,065	1,165
Research Equipment
Property Plant And Equipment [Line Items]
Total property and equipment	2,144	2,107
Office Equipment and Furniture
Property Plant And Equipment [Line Items]
Total property and equipment	532	532
Leasehold Improvement
Property Plant And Equipment [Line Items]
Total property and equipment	$ 253	$ 253

Fair Value Measurements - Additional Information (Details)	3 Months Ended
	Mar. 31, 2024 USD ($)
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair value, transfer of liabilities, from level 1 to level 2	$ 0
Fair value, transfer of liabilities from level 2 to level 1	0
Fair value, transfer of assets into level 3	0
Fair value, transfer of assets out of level 3	0
Fair value, transfer of liabilities into level 3	0
Fair value, transfer of liabilities out of level 3	$ 0

CONDENSED CONSOLIDATED STATEMENTS OF COMMON STOCK AND STOCKHOLDERS' EQUITY (Unaudited) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Loss
Beginning balance at Dec. 31, 2022	$ 103,407	$ 3	$ 302,202	$ (197,794)	$ (1,004)
Beginning balance, shares at Dec. 31, 2022		30,764,160
Stock-based compensation expense	1,213		1,213
Issuance of equity in exchange for compensation	302		302
Issuance of equity in exchange for compensation, Shares		208,510
Surrender of shares for tax withholding	(76)		(76)
Surrender of shares for tax withholding, Shares		(50,343)
Vesting of restricted stock shares, shares		49,014
Unrealized gain on marketable securities	181				181
Net Income (Loss)	(10,177)			(10,177)
Ending balance at Mar. 31, 2023	94,850	$ 3	303,641	(207,971)	(823)
Ending balance, shares at Mar. 31, 2023		30,971,341
Beginning balance at Dec. 31, 2023	64,895	$ 3	296,996	(231,895)	(209)
Beginning balance, shares at Dec. 31, 2023		25,030,188
Stock-based compensation expense	1,216		1,216
Issuance of equity in exchange for compensation	293		293
Surrender of shares for tax withholding	(10)		(10)
Surrender of shares for tax withholding, Shares		(12,361)
Vesting of restricted stock shares, shares		56,131
Unrealized gain on marketable securities	72				72
Net Income (Loss)	(7,992)			(7,992)
Ending balance at Mar. 31, 2024	$ 58,474	$ 3	$ 298,495	$ (239,887)	$ (137)
Ending balance, shares at Mar. 31, 2024		25,073,958

Organization and Operations - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Net loss	$ (7,992)	$ (10,177)
Accumulated deficit	(239,887)		$ (231,895)
Cash, cash equivalents and marketable securities	$ 58,100

- Definition

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

+ References

+ Details

- Definition

Amount of accumulated undistributed earnings (deficit).

+ References + Details

Employee Retirement Plan

3 Months Ended

Mar. 31, 2024

Retirement Benefits [Abstract]

EMPLOYEE RETIREMENT PLAN

9. EMPLOYEE RETIREMENT PLAN

The Company maintains a defined contribution 401(k) profit-sharing plan (the “Plan”) for all employees. Under the Plan, participants may make voluntary contributions up to the maximum amount allowable by law. The Plan is based on employees’ salary deferral, and the Company matches employees’ contributions up to 4% of the employees’ base salary. Employees are 100% vested in the Company’s match contributions. During the three months ended March 31, 2024 and 2023, the Company’s matching contributions were $82 thousand and $89 thousand, respectively.

- Definition

The entire disclosure for retirement benefits.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 70
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480794/715-70-50-1

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 17
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480482/715-20-55-17

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (d)(iv)(03)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480506/715-20-50-1

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (d)(i)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480506/715-20-50-1

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (q)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480506/715-20-50-1

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (l)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480506/715-20-50-1

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org//715/tableOfContent

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (d)(iii)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480506/715-20-50-1

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (o)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480506/715-20-50-1

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (p)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480506/715-20-50-1

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (r)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480506/715-20-50-1

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (r)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480506/715-20-50-1

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480126/715-20-S99-2

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 60
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480266/715-60-50-3

+ Details

Commitments and Contingencies - Summary of Maturity of Operating and Finance Lease Liabilities (Details) $ in Thousands	Mar. 31, 2024 USD ($)
Operating
Remainder of 2024	$ 1,397
2025	1,736
2026	1,413
2027	59
Total future minimum lease payments	4,605
Less amount representing interest	408
Total lease liabilities	4,197
Financing
Remainder of 2024	675
2025	757
2026	107
Total future minimum lease payments	1,539
Less amount representing interest	97
Total lease liabilities	$ 1,442

Summary of Significant Accounting Policies

3 Months Ended

Mar. 31, 2024

Accounting Policies [Abstract]

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

Basis of Presentation and Principles of Consolidation

Unaudited interim financial information

Use of Estimates

Cash and cash equivalents

Marketable securities

Property and Equipment


Office equipment and furniture	3—7 years
Research equipment	1—7 years

Leases

Recently Issued Accounting Standards

Property and Equipment, Net (Tables)

3 Months Ended

Mar. 31, 2024

Property, Plant and Equipment [Abstract]

Summary of Property and Equipment, Net

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


	March 31, 2024			December 31, 2023
Research equipment	$	2,144		$	2,107
Office equipment and furniture		532			532
Leasehold improvement		253			253
Total property and equipment		2,929			2,892
Less accumulated depreciation and amortization		(1,864	)		(1,727	)
Property and equipment, net	$	1,065		$	1,165

Document and Entity Information - shares	3 Months Ended
Document and Entity Information - shares	Mar. 31, 2024	May 01, 2024
Document Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2024
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q1
Entity Registrant Name	Sensei Biotherapeutics, Inc.
Entity Central Index Key	0001829802
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		25,080,958
Entity Shell Company	false
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity File Number	001-39980
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	83-1863385
Entity Address, Address Line One	1405 Research Blvd
Entity Address, Address Line Two	Suite 125
Entity Address, City or Town	Rockville
Entity Address, State or Province	MD
Entity Address, Postal Zip Code	20850
City Area Code	240
Local Phone Number	243-8000
Document Quarterly Report	true
Document Transition Report	false
Common Stock
Document Information [Line Items]
Title of 12(b) Security	Common Stock, $0.0001 par value per share
Trading Symbol	SNSE
Security Exchange Name	NASDAQ
Series A Preferred Stock Purchase Rights
Document Information [Line Items]
Title of 12(b) Security	Series A Preferred Stock Purchase Rights
No Trading Symbol Flag	true
Security Exchange Name	NASDAQ

Stock-Based Compensation - Summary of Employee-issued Common Stock Warrant Activity (Details) - $ / shares	3 Months Ended	12 Months Ended
	Mar. 31, 2024	Dec. 31, 2023
Share-Based Payment Arrangement [Abstract]
Number of Common Stock Warrants Outstanding and Exercisable, Beginning Balance	56,692
Number of Common Stock Warrants Outstanding and Exercisable, Ending Balance	56,692	56,692
Weighted-Average Exercise Price Outstanding and Exercisable, Beginning Balance	$ 6.19
Weighted-Average Exercise Price Outstanding and Exercisable, Ending Balance	$ 6.19	$ 6.19
Weighted-Average Remaining Contractual Term Outstanding and Exercisable	10 months 28 days	1 year 1 month 28 days

Stock-Based Compensation - Summary of Fair Value Assumptions and Methodology (Details)	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Volatility, Minimum	91.00%
Volatility		93.00%
Volatility, Maximum	93.00%
Risk-free interest rate, Minimum	3.90%	3.60%
Risk-free interest rate, Maximum	4.20%	4.00%
Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (years)	5 years	6 years
Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (years)	6 years	7 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

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 35
-Paragraph 1D
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480483/718-10-35-1D

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 35
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480483/718-10-35-3

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)(3)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(i)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(ii)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iii)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iv)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iv)(01)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iv)(02)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iv)(03)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iv)(04)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(i)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(ii)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(01)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(02)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 19: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(03)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 20: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (d)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 21: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (d)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 22: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (e)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 23: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (e)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 24: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (f)(2)(i)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 25: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (f)(2)(ii)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 26: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (f)(2)(iii)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 27: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (f)(2)(iv)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 28: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (f)(2)(v)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

+ Details

Related-Party Transactions - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	Aug. 15, 2023	Jul. 31, 2023	Jun. 01, 2023	May 23, 2023
Purchase Agreement \| Apeiron Parties
Related Party Transaction [Line Items]
Share repurchase, agreed to purchase, shares				4,454,248
Purchase price per share				$ 1.58
Purchase transaction cost			$ 7,800
Negotiation of purchase agreement cost			$ 750
Company 's outstanding shares of common stock				5.00%
Cambrian Purchase Agreement
Related Party Transaction [Line Items]
Share repurchase, agreed to purchase, shares		1,587,302
Purchase price per share		$ 1.26
Aggregate purchase price		$ 2,000
Shares repurchased and retired	1,587,302
Cambrian Purchase Agreement \| Cambrian BioPharma, Inc
Related Party Transaction [Line Items]
Company 's outstanding shares of common stock		5.00%

Stock-Based Compensation - Summary of Restricted Stock Unit Activity (Details) - Restricted Stock Units	3 Months Ended
	Mar. 31, 2024 $ / shares shares
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Restricted Stock Units, Unvested balance \| shares	232,958
Restricted Stock Units, Vested \| shares	(63,131)
Restricted Stock Units, Forfeited \| shares	(7,866)
Restricted Stock Units, Unvested balance \| shares	161,961
Weighted-Average Grant Date Fair Value, Unvested balance \| $ / shares	$ 2.53
Weighted-Average Grant Date Fair Value, Vested \| $ / shares	2.91
Weighted-Average Grant Date Fair Value, Forfeited \| $ / shares	2.55
Weighted-Average Grant Date Fair Value, Unvested balance \| $ / shares	$ 2.38

- 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

Equity - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	Aug. 15, 2023	Jul. 31, 2023	Jun. 01, 2023	May 23, 2023	Jan. 01, 2023
Class of Stock [Line Items]
Excise tax on repurchases					1.00%
Purchase Agreement \| Apeiron Parties
Class of Stock [Line Items]
Purchase price per share				$ 1.58
Share repurchase, agreed to purchase, shares				4,454,248
Purchase transaction cost			$ 7,800
Negotiation of purchase agreement cost			$ 750
Cambrian Purchase Agreement [Member]
Class of Stock [Line Items]
Shares repurchased and retired	1,587,302
Purchase price per share		$ 1.26
Share repurchase, agreed to purchase, shares		1,587,302
Aggregate purchase price		$ 2,000

Marketable Securities - Additional Information (Details)	3 Months Ended
	Mar. 31, 2024 USD ($)
Marketable Securities [Line Items]
Marketable securities, unrealized loss position, fair value	$ 100,000
Impairment of investments	$ 0
Maximum
Marketable Securities [Line Items]
Marketable securities remaining maturity term	1 year
Marketable securities unrealized loss position, maturity term	1 year

Stock-Based Compensation - Summary of Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 1,216	$ 1,213
Research and Development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	339	292
General and Administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 877	$ 921

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Current assets:
Cash and cash equivalents	$ 10,956	$ 13,011
Marketable securities	47,125	52,746
Prepaid expenses	1,884	1,168
Other current assets	269	325
Total current assets	60,234	67,250
Right of use assets - operating leases, net	3,960	4,330
Right of use assets - financing leases, net	1,350	1,543
Property and equipment, net	1,065	1,165
Other non-current assets	86	86
Total assets	66,695	74,374
Current liabilities:
Accounts payable and accrued liabilities	2,000	1,694
Compensation and employee benefits liabilities	514	1,510
Operating lease liabilities, current	1,607	1,567
Financing lease liabilities, current	871	872
Total current liabilities	4,992	5,643
Operating lease liabilities, non-current	2,590	3,001
Financing lease liabilities, non-current	571	768
Other non-current liabilities	68	67
Total liabilities	8,221	9,479
Commitments and contingencies (Note 6)
Stockholders' equity:
Preferred stock, $0.0001 par value and 10,000,000 shares authorized as of March 31, 2024 and December 31, 2023; zero shares issued and outstanding at March 31, 2024 and December 31, 2023, respectively
Common stock, $0.0001 par value and 250,000,000 shares authorized as of March 31, 2024 and December 31, 2023; 25,073,958 and 25,030,188 shares issued and outstanding at March 31, 2024 and December 31, 2023, respectively	3	3
Additional paid-in capital	298,495	296,996
Accumulated deficit	(239,887)	(231,895)
Accumulated other comprehensive loss	(137)	(209)
Total stockholders' equity	58,474	64,895
Total liabilities and stockholders' equity	$ 66,695	$ 74,374