Unity Biotechnology (UBX) 10-Q 9 May 23 2023 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2023	May 05, 2023
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Transition Report	false
Amendment Flag	false
Document Period End Date	Mar. 31, 2023
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q1
Trading Symbol	UBX
Entity Registrant Name	Unity Biotechnology, Inc.
Entity Central Index Key	0001463361
Current Fiscal Year End Date	--12-31
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Current Reporting Status	Yes
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Common Stock, Shares Outstanding		14,365,038
Entity Shell Company	false
Entity File Number	001-38470
Entity Tax Identification Number	26-4726035
Entity Incorporation, State or Country Code	DE
Entity Address, Address Line One	285 East Grand Ave.
Entity Address, City or Town	South San Francisco
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94080
City Area Code	650
Local Phone Number	416-1192
Title of 12(b) Security	Common Stock, par value $0.0001
Security Exchange Name	NASDAQ

Condensed Balance Sheets (Unaud

Condensed Balance Sheets (Unaudited) - USD ($) $ in Thousands		Mar. 31, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents		$ 22,972	$ 12,736	[1]
Short-term marketable securities		60,420	82,059	[1]
Prepaid expenses and other current assets		2,989	1,740	[1]
Total current assets		86,381	96,535	[1]
Property and equipment, net		7,496	7,825	[1]
Operating lease right-of-use assets		18,557	19,042	[1]
Long-term deposits		896	0	[1]
Long-term restricted cash		896	896	[1]
Other long-term assets		29	52	[1]
Total assets		114,255	124,350	[1]
Current liabilities:
Accounts payable		1,470	1,790	[1]
Accrued compensation		1,983	3,020	[1]
Accrued and other current liabilities		5,343	5,334	[1]
Current portion of long-term debt		13,062	9,476	[1]
Total current liabilities		21,858	19,620	[1]
Operating lease liability, net of current portion		26,150	26,991	[1]
Long-term debt, net		7,619	10,891	[1]
Total liabilities		55,627	57,502	[1]
Commitments and contingencies (Note 7)
Stockholders’ equity:
Convertible preferred stock, $0.0001 par value; 10,000,000 shares authorized; no shares issued and outstanding		0	0	[1]
Common stock, $0.0001 par value; 300,000,000 shares authorized as of March 31, 2023 and December 31, 2022; 14,359,214 and 14,215,302 shares issued and outstanding as of March 31, 2023 and December 31, 2022, respectively(2)	[2]	1	1	[1]
Additional paid-in capital		529,593	527,049	[1]
Accumulated other comprehensive loss		(150)	(251)	[1]
Accumulated deficit		(470,816)	(459,951)	[1]
Total stockholders’ equity		58,628	66,848	[1]
Total liabilities and stockholders’ equity		$ 114,255	$ 124,350	[1]
[1] The balance sheet as of December 31, 2022 is derived from the audited financial statements as of that date. The Company effected a reverse stock split of its outstanding shares of common stock on October 19, 2022 where every ten shares of its common stock issued and outstanding was converted into one share of common stock. Any fractional post-split shares as a result of the reverse split were rounded down to the nearest whole post-split share. Shareholders of the Company previously authorized the Board of Directors to approve a reverse stock split at the annual meeting on October 18, 2022. All share amounts and per share amounts disclosed in this Quarterly Report on Form 10-Q have been restated to reflect the reverse stock split on a retroactive basis in all periods presented.

Condensed Balance Sheets (Paren

Condensed Balance Sheets (Parenthetical) (Unaudited)	Mar. 31, 2023 $ / shares shares	Dec. 31, 2022 $ / shares shares
Statement Of Financial Position [Abstract]
Convertible preferred stock, par value | $ / shares	$ 0.0001	$ 0.0001
Convertible preferred stock, shares authorized	10,000,000	10,000,000
Convertible preferred stock, shares issued	0	0
Convertible preferred stock, shares outstanding	0	0
Common stock, par value | $ / shares	$ 0.0001	$ 0.0001
Common stock, shares authorized	300,000,000	300,000,000
Common stock, shares issued	14,359,214	14,215,302
Common stock, shares outstanding	14,359,214	14,215,302

Condensed Statements of Operati

Condensed Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2023	Mar. 31, 2022
Operating expenses:
Research and development		$ 5,835	$ 12,461
General and administrative		4,818	5,806
Total operating expenses		10,653	18,267
Loss from operations		(10,653)	(18,267)
Interest income		855	29
Interest expense		(1,002)	(808)
Other income (expense), net		(65)	131
Net loss		(10,865)	(18,915)
Other comprehensive (loss) gain
Unrealized gain (loss) on marketable debt securities		101	(132)
Comprehensive loss		$ (10,764)	$ (19,047)
Net loss per share, basic		$ (0.76)	$ (2.80)
Net loss per share, diluted		$ (0.76)	$ (2.80)
Weighted-average number of shares used in computing net loss per share, basic	[1]	14,312,887	6,752,855
Weighted-average number of shares used in computing net loss per share, diluted	[1]	14,312,887	6,752,855
[1] The Company effected a reverse stock split of its outstanding shares of common stock on October 19, 2022 where every ten shares of its common stock issued and outstanding was converted into one share of common stock. Any fractional post-split shares as a result of the reverse split were rounded down to the nearest whole post-split share. Shareholders of the Company previously authorized the Board of Directors to approve a reverse stock split at the annual meeting on October 18, 2022. All share amounts and per share amounts disclosed in this Quarterly Report on Form 10-Q have been restated to reflect the reverse stock split on a retroactive basis in all periods presented.

Condensed Statements of Opera_2

Condensed Statements of Operations and Comprehensive Loss (Parenthetical) (Unaudited)	Oct. 19, 2022
Statement Of Income And Comprehensive Income [Abstract]
Reverse stock split ratio	0.1

Condensed Statements of Stockho

Condensed Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands		Total		Hercules Capital	At The Market Equity Offering Program	Equity Purchase Agreement Lincoln Park Capital Fund LLC	Common Stock		Common Stock Hercules Capital	Common Stock At The Market Equity Offering Program	Common Stock Equity Purchase Agreement Lincoln Park Capital Fund LLC	Additional Paid-In Capital	Additional Paid-In Capital Hercules Capital	Additional Paid-In Capital At The Market Equity Offering Program	Additional Paid-In Capital Equity Purchase Agreement Lincoln Park Capital Fund LLC	Accumulated Other Comprehensive Gain (Loss)	Accumulated Deficit
Beginning balance at Dec. 31, 2021		$ 59,569					$ 1	[1]				$ 459,636				$ (44)	$ (400,024)
Beginning balance, (in shares) at Dec. 31, 2021	[1]						6,299,158
Issuance of common stock, net of issuance costs				$ 3,179	$ 3,420	$ 910							$ 3,179	$ 3,420	$ 910
Issuance of common stock (in shares)	[1]								262,761	232,500	90,000
Vesting of restricted stock units, (in shares)	[1]						30,358
Stock-based compensation		2,660										2,660
Unrealized gain (loss) on marketable debt securities		(132)														(132)
Net loss		(18,915)															(18,915)
Ending balance at Mar. 31, 2022		50,691					$ 1	[1]				469,805				(176)	(418,939)
Ending balance, (in shares) at Mar. 31, 2022	[1]						6,914,777
Beginning balance at Dec. 31, 2021		59,569					$ 1	[1]				459,636				(44)	(400,024)
Beginning balance, (in shares) at Dec. 31, 2021	[1]						6,299,158
Issuance of common stock (in shares)						380,000
Ending balance at Dec. 31, 2022		$ 66,848	[2]				$ 1					527,049				(251)	(459,951)
Ending balance, (in shares) at Dec. 31, 2022		14,215,302					14,215,302
Issuance of common stock, net of issuance costs					$ 274									$ 274
Issuance of common stock (in shares)										106,781
Vesting of restricted stock units, (in shares)							37,131
Stock-based compensation		$ 2,270										2,270
Unrealized gain (loss) on marketable debt securities		101														101
Net loss		(10,865)															(10,865)
Ending balance at Mar. 31, 2023		$ 58,628					$ 1					$ 529,593				$ (150)	$ (470,816)
Ending balance, (in shares) at Mar. 31, 2023		14,359,214					14,359,214
[1] The Company effected a reverse stock split of its outstanding shares of common stock on October 19, 2022 where every ten shares of its common stock issued and outstanding was converted into one share of common stock. Any fractional post-split shares as a result of the reverse split were rounded down to the nearest whole post-split share. Shareholders of the Company previously authorized the Board of Directors to approve a reverse stock split at the annual meeting on October 18, 2022. All share amounts and per share amounts disclosed in this Quarterly Report on Form 10-Q have been restated to reflect the reverse stock split on a retroactive basis in all periods presented. The balance sheet as of December 31, 2022 is derived from the audited financial statements as of that date.

Condensed Statements of Cash Fl

Condensed Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Operating activities
Net loss	$ (10,865)	$ (18,915)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	329	627
Amortization of debt issuance costs	314	322
Debt extinguishment gain upon conversion to equity	0	(199)
Net accretion and amortization of premium and discounts on marketable securities	(433)	131
Stock-based compensation	2,270	2,660
Non-cash rent expense	(270)	(626)
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	(1,249)	110
Other long-term assets	23	14
Accounts payable	(320)	1,345
Accrued compensation	(1,037)	(1,191)
Accrued liabilities and other current liabilities	(78)	774
Other long-term liabilities	0	(24)
Net cash used in operating activities	(11,316)	(14,972)
Investing activities
Purchase of marketable securities	(5,973)	(17,067)
Maturities of marketable securities	27,251	11,250
Net cash provided by (used in) investing activities	21,278	(5,817)
Financing activities
Net cash provided by financing activities	274	4,330
Net increase (decrease) in cash, cash equivalents and restricted cash	10,236	(16,459)
Cash, cash equivalents and restricted cash at beginning of the period	13,632	34,351	$ 34,351
Cash, cash equivalents and restricted cash at end of the period	23,868	17,892	13,632
Supplemental Disclosures of Cash Flow Information:
Cash paid for interest	680	518
Supplemental Disclosures of Non-Cash Investing and Financing Activities
Issuance of common stock in payment of debt	0	3,178
Cash and cash equivalents	22,972	16,446	12,736	[1]
Restricted cash	896	1,446
Total cash, cash equivalents and restricted cash	23,868	17,892	$ 13,632
ATM Offering Program
Financing activities
Proceeds from issuance of common stock, net of issuance costs	274	3,420
Lincoln Park Capital Fund Equity Purchase Agreement
Financing activities
Proceeds from issuance of common stock, net of issuance costs	$ 0	$ 910
[1] The balance sheet as of December 31, 2022 is derived from the audited financial statements as of that date.

Organization

Organization	3 Months Ended
	Mar. 31, 2023
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Organization	1. Organization Description of Business Unity Biotechnology, Inc. (the “Company”) is a biotechnology company engaged in the research and development of therapeutics to slow, halt, or reverse diseases of aging. The Company devotes substantially all of its time and efforts to performing research and development and raising capital. The Company’s headquarters are located in South San Francisco, California. The Company was incorporated in the State of Delaware in 2009. Liquidity The Financial Statements have been prepared assuming that the Company will continue as a going concern, which contemplates the realization of assets and the settlement of liabilities and commitments in the normal course of business. The Company has incurred operating losses and has an accumulated deficit as a result of ongoing efforts to develop drug product candidates, including conducting preclinical and clinical trials and providing general and administrative support for these operations. The Company had an accumulated deficit of $ 470.8 million and $ 460.0 million as of March 31, 2023 and December 31, 2022, respectively. The Company had net losses of $ 10.9 million and $ 18.9 million for the three months ended March 31, 2023 and 2022, respectively, and net cash used in operating activities of $ 11.3 million and $ 15.0 million for the three months ended March 31, 2023 and 2022, respectively. To date, none of the Company’s drug product candidates have been approved for sale, and therefore, the Company has no t generated any product revenue and does not expect positive cash flows from operations in the foreseeable future. The Company has financed its operations primarily through private placements of preferred stock and promissory notes, public equity issuances and more recently, from its ATM Offering Programs (as defined in Note 9), the Term Loan Facility (as defined in Note 8), an Equity Purchase Agreement (as defined in Note 9), and the sale of common stock and warrants under a Follow-On Offering (as defined in Note 9) and will continue to be dependent upon equity and/or debt financing until the Company is able to generate positive cash flows from its operations. The Company had cash, cash equivalents, and marketable securities of $ 83.4 million as of March 31, 2023. The Company anticipates operating losses and negative operating cash flows to continue for the foreseeable future. These conditions raised substantial doubt about its ability to continue as a going concern within one year after the date that the financial statements are issued prior to the implementation of the Company's revised operating plan. To alleviate the conditions that raise substantial doubt about the Company’s ability to continue as a going concern, it needs to raise additional capital to complete pivotal trials and advance our programs. Although the Company has been successful in raising capital in the past, there is no assurance that it will be successful in obtaining such additional financing. In addition, management has implemented a reduction in expenditures including a 29 % reduction in force and reduced clinical program spend. The implementation of management’s plan to reduce expenditures has alleviated the substantial doubt regarding the Company’s ability to continue as a going concern within one year after the date that these Financial Statements are issued. The future viability of the Company is dependent on its ability raise additional capital to finance its operations. If sufficient funds on acceptable terms are not available when needed, the Company could be further required to significantly reduce its operating expenses and delay, reduce the scope of, or eliminate one or more of its development programs. Failure to manage discretionary spending or raise additional financing, as needed, may adversely impact the Company’s ability to achieve its intended business objectives.

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2023
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Basis of Presentation These condensed financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) and the rules and regulations of the United States Securities and Exchange Commission (“SEC”) for interim reporting. Certain information and footnote disclosures normally included in annual financial statements prepared in accordance with GAAP have been condensed or omitted. Accordingly, the unaudited condensed financial statements should be read in conjunction with the audited financial statements and the related notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2022 filed with the SEC. The Company effected a reverse stock split on October 19, 2022 of its outstanding shares of common stock at a ratio of 1-for-10 pursuant to a Certificate of Amendment to the Company's Certificate of Incorporation filed with the Secretary of State of the State of Delaware. The reverse stock split was reflected on the Nasdaq Global Select Market beginning with the opening of trading on October 20, 2022. The reverse stock split did not change the par value of the Company's common stock or the authorized number of shares of the Company's common stock. All share amounts and per share amounts disclosed in this Quarterly Report on Form 10-Q have been restated to reflect the reverse stock split on a retroactive basis in all periods presented. Unaudited Condensed Financial Statements The accompanying financial information for the three months ended March 31, 2023 and 2022 are unaudited. The unaudited condensed financial statements have been prepared on the same basis as the annual audited financial statements and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary to present fairly the Company’s financial position as of March 31, 2023 and its results of operations for the three months ended March 31, 2023 and 2022 and cash flows for the three months ended March 31, 2023 and 2022. The results for interim periods are not necessarily indicative of the results expected for the full fiscal year or any other periods. Use of Estimates The condensed financial statements have been prepared in accordance with GAAP, which requires management to make estimates and assumptions that affect the amounts and disclosures reported in the condensed financial statements and accompanying notes. The Company bases its estimates on historical experience and market-specific or other relevant assumptions that it believes are reasonable under the circumstances. The amounts of assets and liabilities reported in the Company’s condensed balance sheets and the amount of expenses and income reported for each of the periods presented are affected by estimates and assumptions, which are used for, but are not limited to, determining the fair value of assets and liabilities, the fair value of right-of-use assets and lease liabilities, and stock-based compensation. Actual results could differ from such estimates or assumptions. Segments The Company has one operating segment. The Company’s chief operating decision maker, its Chief Executive Officer, manages the Company’s operations on a consolidated basis for the purposes of allocating resources. Recently Adopted Accounting Pronouncements In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments—Credit Losses (Topic 326) , Measurement of Credit Losses on Financial Instruments , as clarified in subsequent amendments. ASU 2016-13 changes the impairment model for certain financial instruments. The new model is a forward-looking expected loss model and will apply to financial assets subject to credit losses and measured at amortized cost and certain off-balance sheet credit exposures. This includes loans, held-to-maturity debt securities, loan commitments, financial guarantees and net investments in leases, as well as trade receivables. For available-for-sale debt securities with unrealized losses, credit losses will be measured in a manner similar to today, except that the losses will be recognized as allowances rather than reductions in the amortized cost of the securities. In October 2019, the FASB voted to delay the effective date of this standard. Topic 326 will be effective for the Company for fiscal years beginning after December 15, 2022. Early adoption is permitted. We adopted ASU 2016-13 on January 1, 2023 and the adoption did no t have a material impact on the Company’s condensed consolidated financial statements and related disclosures. In November 2021, the FASB issued ASU 2021-10, Government Assistance, or Topic 832, which requires enhanced disclosures of transactions with governments that are accounted for by applying a grant or contribution model. The new pronouncement requires entities to provide information about the nature of the transaction, terms and conditions associated with the transaction and financial statement line items affected by the transaction. The Company adopted the standard for the annual period beginning January 1, 2023 . The employee retention credit received under the CARES Act qualifies as a government assistance program under Topic 832 and resulted in enhanced required disclosures, as described in Note 6.

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2023
Fair Value Disclosures [Abstract]
Fair Value Measurements	3. Fair Value Measurements The Company determines the fair value of financial and non-financial assets and liabilities based on the assumptions that market participants would use in pricing the asset or liability in an orderly transaction between market participants at the measurement date. The identification of market participant assumptions provides a basis for determining what inputs are to be used for pricing each asset or liability. A fair value hierarchy has been established which gives precedence to fair value measurements calculated using observable inputs over those using unobservable inputs. This hierarchy prioritized the inputs into three broad levels as follows: • Level 1: Quoted prices in active markets for identical instruments • Level 2: Other significant observable inputs (including quoted prices in active markets for similar instruments) • Level 3: Significant unobservable inputs (including assumptions in determining the fair value of certain investments) The carrying amounts of financial instruments such as cash and cash equivalents, restricted cash, prepaid expenses and other current assets, accounts payable, accrued compensation, accrued and other current liabilities approximate the related fair values due to the short maturities of these instruments. As the long-term debt is subject to variable interest rates that are based on market rates which are regularly reset, considering level 2 inputs, the Company believes the carrying value of the long-term debt approximates its fair value. The Company’s financial assets and liabilities subject to fair value measurements on a recurring basis and the level of inputs used in such measurements were as follows (in thousands): March 31, 2023 Total Level 1 Level 2 Level 3 Assets: Cash equivalents: Money market funds $ 18,910 $ 18,910 $ — $ — Long-term certificates of deposits 896 — 896 — Total cash equivalents 19,806 18,910 896 — Short-term marketable securities: U.S. and foreign commercial paper — — — — U.S. and foreign corporate debt securities — — — — U.S. treasuries 8,728 — 8,728 — U.S. government debt securities 51,692 — 51,692 — Total short-term marketable securities 60,420 — 60,420 — Total assets subject to fair value measurements $ 80,226 $ 18,910 $ 61,316 $ — December 31, 2022 Total Level 1 Level 2 Level 3 Assets: Cash equivalents: Money market funds $ 5,083 $ 5,083 $ — $ — Total cash equivalents 5,083 5,083 — — Short-term marketable securities: U.S. treasuries 30,758 — 30,758 — U.S. government debt securities 51,301 — 51,301 — Total short-term marketable securities 82,059 — 82,059 — Total assets subject to fair value measurements $ 87,142 $ 5,083 $ 82,059 $ — The Company estimates the fair value of its money market funds, certificates of deposits, U.S. and foreign commercial paper, U.S. and foreign corporate debt securities, U.S. treasuries, and U.S. government debt securities by taking into consideration valuations obtained from third-party pricing services. Based upon the Company's intent and ability to hold its certificates of deposit to maturity, such securities have been classified as held-to-maturity and are carried at amortized cost, which approximates market value. The pricing services utilize industry standard valuation models, including both income and market-based approaches, for which all significant inputs are observable, either directly or indirectly, to estimate fair value. These inputs include reported trades of and broker/dealer quotes on the same or similar securities, issuer credit spreads; benchmark securities; prepayment/default projections based on historical data; and other observable inputs. See Note 4, “Marketable Securities,” for further information regarding the carrying value of the Company's financial instruments.

Marketable Securities

Marketable Securities	3 Months Ended
	Mar. 31, 2023
Investments Debt And Equity Securities [Abstract]
Marketable Securities	4. Marketable Securities Marketable securities, which are classified as available-for-sale, consisted of the following as of March 31, 2023, (in thousands): Amortized Unrealized Unrealized Fair Cash equivalents: Money market funds $ 18,910 $ — $ — $ 18,910 Total cash equivalents 18,910 — — 18,910 Short-term marketable securities: U.S. treasuries 8,734 — ( 6 ) 8,728 U.S. government debt securities 51,836 13 ( 157 ) 51,692 Total short-term marketable securities 60,570 13 ( 163 ) 60,420 Total $ 79,480 $ 13 $ ( 163 ) $ 79,330 Marketable securities, which are classified as available-for-sale, consisted of the following as of December 31, 2022 (in thousands): Amortized Unrealized Unrealized Fair Cash equivalents: Money market funds $ 5,083 $ — $ — $ 5,083 Total cash equivalents 5,083 — — 5,083 Short-term marketable securities: U.S. treasuries 30,820 1 ( 63 ) 30,758 U.S. government debt securities 51,491 6 ( 196 ) 51,301 Total short-term marketable securities 82,311 7 ( 259 ) 82,059 Total $ 87,394 $ 7 $ ( 259 ) $ 87,142 At March 31, 2023, the remaining contractual maturities of available-for-sale securities were less than one year . There have been no significant realized gains or losses on available-for-sale securities for the periods presented. As of March 31, 2023, the Company did not hold any individual securities in an unrealized loss position for 12 months or greater. The Company has the ability and intent to hold all marketable securities that have been in a continuous loss position until maturity or recovery. No significant facts or circumstances have arisen to indicate that there has been any significant deterioration in the creditworthiness of the issuers of the securities held by the Company. The Company considered the current and expected future economic and market conditions and determined that the estimate of credit losses was not significantly impacted. Thus, there has been no change in estimate of expected credit loss during the three months ended March 31, 2023 and no allowance for credit loss was recorded at March 31, 2023. The Company will continue to assess the current and expected future economic and market conditions as further development arises. See Note 3, “Fair Value Measurements,” for further information regarding the fair value of the Company’s financial instruments.

License Revenue and Agreements

License Revenue and Agreements	3 Months Ended
	Mar. 31, 2023
Research And Development [Abstract]
License Revenue and Agreements	5. License Revenue and Agreements The Company has entered into license agreements with other pharmaceutical and biotechnology companies. The Company’s accounts receivable balances may contain billed and unbilled amounts from milestones and other contingent payments. The Company performs a regular review of its customers’ credit risk and payment histories, including payments made after period end. Historically, the Company has not experienced credit loss from its accounts receivable and, therefore, has not recorded a reserve for estimated credit losses as of March 31, 2023 and December 31, 2022. License Agreement with Jocasta Neuroscience, Inc. In December 2021, the Company signed a License Agreement with Jocasta Neuroscience, Inc. (“the Jocasta Agreement”) to exclusively license its rights in the α-Klotho asset for development and commercialization, and included a sublicense agreement under the original license agreement with the University of California, San Francisco. Under the Jocasta Agreement, the Company received a $ 5.0 million upfront cash payment from Jocasta Neuroscience, Inc. The Company may also receive additional payments based on development milestones, approval milestones, and sales-based royalties, per indication. The Jocasta agreement is recognized in accordance with ASC 606, Revenue from Contracts with Customers , and is classified under License Revenue. Promises that the Company concluded were distinct performance obligations in the License Agreement included: (1) the license of intellectual property and delivery of know-how, and (2) the transfer of licensed compounds and materials. In order to determine the transaction price, the Company evaluated all the payments to be received during the duration of the contract. Fixed consideration exists in the form of the upfront payment. Regulatory milestones and royalties were considered variable consideration. The estimated variable consideration is constrained until the Company determines it is probable that a significant reversal in the amount of cumulative revenue recognized will not occur in future periods. Milestone payments are constrained and not included in the transaction price due to the uncertainties of research and development. The Company will re-evaluate the transaction price, including the estimated variable consideration included in the transaction price and all constrained amounts, in each reporting period and as uncertain events are resolved or other changes in circumstances occur. The Company determined that the initial transaction price consists of the upfront payment of $ 5.0 million. The allocation of the transaction price is performed based on standalone selling prices, which are based on estimated amounts that the Company would charge for a performance obligation if it were sold separately. The transaction price allocated to the license of intellectual property and delivery of know-how was recognized upon grant of license and delivery of know-how. The transaction price allocated the transfer of licensed compounds and materials, will be recognized over time as the materials are delivered. Consideration received in advance are recorded as deferred revenue and will be recognized as the performance obligations are satisfied. No license revenue was recognized for the three months ended March 31, 2023 and 2022 related to the Jocasta Agreement. The deferred revenue balance was zero as of March 31, 2023 and December 31, 2022. License Agreements with Research Institutions In May 2019, the Company entered into a license agreement with The Regents of the University of California on behalf its San Francisco campus (collectively, “UCSF”) which provides the Company the rights to certain patents and related know-how to make, use, sell, offer for sale and import certain products and practice certain methods for use in the development of human therapeutics, which excludes the provision of services to third parties for consideration of any kind. The license to the Company is subject to UCSF’s reserved rights under the licensed intellectual property for educational and non-commercial research purposes and a requirement to substantially manufacture any licensed products in the United States. The Company is obligated to use diligent efforts to develop and obtain regulatory approval for at least one product commercialized pursuant to the agreement, and must meet certain regulatory and development milestones. The Company is obligated to pay an annual license maintenance fee and may be obligated to make milestone payments or issue up to an additional 3,400 shares of its common stock upon the occurrence of specified development events, up to aggregate milestone payments of $ 13.6 million for each product licensed under the agreement, and upon commercialization, to make royalty payments in the low single digit percentages (subject to a specified minimum annual royalty) based on net sales of products commercialized pursuant to the agreement. None of these events had occurred and no milestone payments or royalty payments had been recognized as of March 31, 2023. In December 2021, the Company entered an agreement to exclusively license its rights in the α-Klotho asset to Jocasta Neuroscience, Inc. for development and commercialization. Under the license agreement, Jocasta Neuroscience, Inc. is, in addition to the payments due to the Company, required to make all payments due to UCSF from the Company under the UCSF License. The Company has also entered into license agreements with various research institutions which have provided the Company with rights to patents, and in certain cases, research “know-how” and proprietary research tools to research, develop and commercialize drug candidates. In addition to upfront consideration paid to these various research institutions in either cash or shares of the Company’s common stock, the Company may be obligated to make milestone payments, payable in cash and/or the issuance of shares of the Company’s common stock upon achievement of certain specified clinical development and/or sales events. The contingent consideration liability considered to be a derivative associated with the potential issuance of common stock related to these license agreements was not significant at March 31, 2023 and 2022. To date, none of these events has occurred and no contingent consideration, milestone or royalty payments have been recognized. Ascentage Commercial Agreements The Company was a party to three agreements (the "Commercial Agreements") with Ascentage Pharma: (a) a compound library and option agreement executed in February 2016 , the Library Agreement, granting the Company the right to research and nominate an active compound from Ascentage’s library of Bcl compounds and subsequently nominate a development candidate from any active compound in order to begin GLP toxicology work for indications outside of oncology, which expired in February 2022 ; (b) a license agreement executed in February 2016 granting the Company rights to an Ascentage Pharma compound known as APG1252, or the APG1252 License Agreement, which the Company terminated in July 2020 due to the Company’s decision to prioritize the progression of UBX1325; and (c) a second license agreement executed in January 2019 granting the Company world-wide rights to develop and commercialize UBX0601, the active parent molecule of our lead drug candidate UBX1325, outside of Greater China, or the Original Bcl Agreement, for indications outside of oncology. The Commercial Agreements referenced above include cash payments of up to $ 70.3 million as well as the equity payments of up to an aggregate of (a) 93,333 shares of common stock in the event there is only one licensed product, and (b) 133,333 shares of common stock in the event there are two or more licensed products, in each case to be issued based on the Company’s achievement of certain preclinical and clinical development and sales milestone events. The Company is required to make 80 % of all equity payments to Ascentage Pharma and the remaining 20 % to an academic institution from whom Ascentage Pharma had previously licensed the technology. The milestones include the advancement of additional compounds into Investigational New Drug application (“IND”) enabling studies, the filing of an IND, the commencement of clinical studies, Food and Drug Administration (“FDA”) and/or European Medicines Agency approval, and a net sales threshold. The Original Bcl License Agreement also includes tiered royalties in the low-single digits based on sales of licensed products. To date, no royalties were due from the sales of licensed products. The Company issued no shares pursuant to these agreements during the three months ended March 31, 2023.

Government Assistance Program

Government Assistance Program	3 Months Ended
	Mar. 31, 2023
Government Assistance [Abstract]
Government Assistance Program	6. Government Assistance Program Under the CARES Act, the Company met eligibility criteria and was approved for a $ 1.5 million refundable employee retention credit. The Company recorded contra-expense to personnel related costs within general and administrative expense of $ 0.4 million and research and development expense of $ 1.1 million for the quarter ended March 31, 2023. No such amounts were recorded for the quarter ended March 31, 2022. The Company had an employee retention credit receivable due from the U.S. Department of Treasury of $ 1.5 million in other current assets as of March 31, 2023 in the balance sheet. There was no employee retention credit receivable due from the U.S. Department of Treasury as of March 31, 2022

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2023
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	7. Commitments and Contingencies Leases In February 2019, the Company entered into a lease agreement for new office and laboratory space in South San Francisco, California. The term of the lease agreement commenced in May 2019 . The lease has an initial term from occupancy of approximately ten years ending on December 31, 2029 with an option to extend the term for an additional eight years at then-market rental rates . The total base rent payment escalates annually based on a fixed percentage beginning from the 13 th month of the lease agreement. The Company will also be responsible for the operating expenses and real estate taxes allocated to the building and common areas. Pursuant to the lease agreement, the landlord provided the Company with a tenant improvement allowance of $ 10.7 million, which was included in deferred rent and leasehold improvements on the balance sheet at December 31, 2019. In connection with the execution of the lease agreement, the Company delivered a letter of credit of approximately $ 0.9 million to the landlord. In May 2016, the Company executed a non-cancellable lease agreement for office and laboratory space in Brisbane, California which commenced in May 2016 and expired in October 2022 . The lease agreement includes an escalation clause for increased rent and a renewal provision allowing the Company to extend this lease for an additional four years by giving the landlord written notice of the election to exercise the option at least fifteen months prior to the original expiration of the lease term. The lease provides for monthly base rent amounts escalating over the term of the lease and the lessor provided the Company a $ 3.9 million tenant improvement allowance to complete the laboratory and office renovation which was recorded as deferred rent liability and leasehold improvements within property and equipment, net. In May 2017, the Company entered into an amendment to expand the leased space and received a three-month rent holiday for the expanded space. The Company’s operating leases include various covenants, indemnities, defaults, termination rights, security deposits and other provisions customary for lease transactions of this nature. The following table summarizes the components of lease expense, which are included in operating expenses in the Company’s condensed statements of operations and comprehensive loss (in thousands): Three Months Ended March 31, 2023 2022 Operating lease cost $ 930 $ 1,078 Variable lease cost 203 296 Sublease income ( 963 ) ( 1,048 ) Total lease cost $ 170 $ 326 Variable lease payments include amounts relating to common area maintenance, real estate taxes and insurance and are recognized in the condensed statements of operations and comprehensive loss as incurred. The following table summarizes supplemental information related to leases (in thousands): Three Months Ended March 31, 2023 2022 Cash paid for amounts included in the measurement of lease liabilities Operating cash flows from operating leases $ 1,200 $ 1,704 Weighted-average remaining lease term (years) Operating leases 6.8 7.8 Weighted-average discount rate (percentage) Operating leases 6.0 % 6.0 % The following table summarizes the maturities of lease liabilities as of March 31, 2023 (in thousands): Amount 2023 (remaining 9 months) $ 3,610 2024 4,964 2025 5,123 2026 5,287 2027 5,457 Thereafter 11,435 Total future minimum lease payments 35,876 Less: Amount representing interest ( 6,540 ) Present value of future minimum lease payments 29,336 Less: Current portion of operating lease liability ( 3,186 ) Noncurrent portion of operating lease liability $ 26,150 In June 2021, the Company entered into an agreement to sublease a portion of the first floor of the South San Francisco, California facility, consisting of approximately 23,000 square feet, to Freenome Holdings, Inc., through August 31, 2024 . The base sublease rent rate is $ 6.25 per rental square foot per month and will increase annually by 3.5 % through expiration of the agreement. Additionally, the subtenant is required to pay approximately 37 % of operating expenses and property management fees that the Company is required to pay under the lease for the South San Francisco, California facility. The Company incurred initial direct costs of $ 0.2 million in sublease commissions related to entering into the agreements to sublease the South San Francisco, California facility. To account for the commissions, the Company capitalized the total commissions amount and will amortize the balance over the term of the sublease. No impairment loss was recorded during the three months ended March 31, 2023 and 2022. Sublease income was $ 0.6 million and $ 0.6 million for the three months ended March 31, 2023 and 2022, respectively, which was offset against total rent expense. In May 2022, the Company entered into an agreement to sublease a portion of the second floor of the South San Francisco, California facility, consisting of approximately 15,000 square feet, to Initial Therapeutics, Inc. The sublease term will commence on July 1, 2022 and continues through June 30, 2024 . The base sublease rent rate is $ 7.80 per rental square foot per month and will increase by 3.5 % annually through the expiration of the agreement. Additionally, the subtenant is required to pay approximately 24 % of operating expenses and property management fees that the Company is required to pay under the lease for the South San Francisco, California facility. The Company incurred initial direct costs of $ 0.1 million in sublease commissions related to entering into the agreements to sublease the South San Francisco, California facility. To account for the commissions, the Company capitalized the total commissions amount and will amortize the balance over the term of the sublease. No impairment loss was recorded during the three months ended March 31, 2023 and 2022. Sublease income was $ 0.4 million and zero for the three months ended March 31, 2023 and 2022, respectively, which was offset against total rent expense. Indemnifications The Company indemnifies each of its officers and directors for certain events or occurrences, subject to certain limits, while the officer or director is or was serving at the Company’s request in such capacity, as permitted under Delaware law and in accordance with the Company’s amended and restated certificate of incorporation and bylaws. The term of the indemnification period lasts as long as an officer or director may be subject to any proceeding arising out of acts or omissions of such officer or director in such capacity. The maximum amount of potential future indemnification is unlimited; however, the Company currently holds director and officer liability insurance. This insurance allows the transfer of risk associated with the Company’s exposure and may enable the Company to recover a portion of any future amounts paid. The Company believes that the fair value of these potential indemnification obligations is minimal. Accordingly, the Company has not recognized any liabilities relating to these obligations for any period presented.

Term Loan Facility

Term Loan Facility	3 Months Ended
	Mar. 31, 2023
Debt Disclosure [Abstract]
Term Loan Facility	8. Term Loan Facility On August 3, 2020, the Company entered into a Loan and Security Agreement (the “Loan Agreement”) with Hercules Capital, Inc. (“Hercules”). Under the Loan Agreement, Hercules provided the Company with access to a term loan with an aggregate principal amount of up to $ 80.0 million (the “Term Loan Facility”), available in four tranches, subject to certain terms and conditions. The first tranche of $ 25.0 million was advanced to the Company on the date the Loan Agreement was executed. The milestones for the remaining tranches have not yet been reached and as of March 31, 2023 are not expected to be reached as they were dependent, in whole or in part, upon continued advancement in the clinical development of UBX0101 in patients with osteoarthritis of the knee. On December 15, 2021, the Company entered into an amendment to the Loan and Security Agreement (“the Loan Amendment”). The Loan Amendment includes a Lender Optional Conversion where after the effective date and until the six-month anniversary of the execution date, the lender may elect to convert to equity of the Company all or any part of up to twenty percent ( 20 %) of the original principal amount for a maximum amount of $ 5.0 million. As of December 31, 2021, the lender had elected to convert $ 2.3 million of the outstanding principal into equity. The Company incurred approximately $ 0.1 million in loan issuance costs relating to the amendment, which were offset against the loan proceeds and are accounted for as a loan discount. During the first quarter of 2022, Hercules Capital, Inc. had elected to convert the remaining convertible debt option into equity of the Company’s common stock. This resulted in the conversion of $ 2.7 million of principal debt into common stock, and reducing the outstanding principal under the first tranche to $ 20.0 million. Pursuant to the Loan Amendment, the Company was able to achieve specific milestones related to its clinical trials and raising additional capital. On January 25, 2023, the Company entered into a second amendment to the Loan and Security Agreement with Hercules Capital, Inc. whereby the amortization date was extended from March 1, 2023 to April 1, 2023. The Company expects to then repay the principal balance and interest in equal monthly installments through August 1, 2024 . The Company may prepay advances under the Loan Agreement, in whole or in part, at any time subject to a prepayment charge of up to 1.50 % of any amount prepaid, depending upon when the prepayment occurs. Upon prepayment or repayment of all or any of the term loans under the Term Loan Facility, the Company is required to pay an end of term fee (“End of Term Fee”) equal to 6.25 % of the total aggregate amount of the term loans being prepaid or repaid, which has been recorded as a discount on the principal balance upon issuance. Interest on the term loan accrues at a per annum rate equal to the greater of (i) the Wall Street Journal prime rate plus 6.10 % and (ii) 9.35 %. On March 31, 2023, the interest rate on the term loan was 14.10 %. Interest expense is calculated using the effective interest method and is inclusive of non-cash amortization of capitalized loan issuance costs. At March 31, 2023, the effective interest rate was 20.37 %. Under the terms of the Loan Agreement, the Company granted first priority liens and security interests in substantially all of the Company’s assets, other than intellectual property, as collateral for the obligations thereunder. The Company also granted Hercules the right, at their discretion, to participate in any closing of any single subsequent financing as defined up to a maximum aggregate amount of $ 2.0 million. The Loan Agreement also contains representations and warranties by the Company and Hercules, indemnification provisions in favor of Hercules and customary affirmative and negative covenants, and events of default, including a material adverse change in the Company’s business, payment defaults, breaches of covenants following any applicable cure period, and a material impairment in the perfection or priority of Hercules’ security interest in the collateral. The liquidity covenant beginning July 1, 2021, originally to maintain $ 15.0 million in unrestricted cash, was subsequently amended on December 15, 2021, requiring the Company to maintain at least $ 10.0 million in unrestricted cash upon the election to convert $ 5.0 million of the loan principal into shares of the Company's common stock. Through February 14, 2022, Hercules had elected to convert the full $ 5.0 million of the loan principal. In the event of default by the Company under the Loan Agreement, the Company may be required to repay all amounts then outstanding under the Loan Agreement. The Company has determined that the risk of subjective acceleration under the material adverse events clause included in the Loan Agreement is remote and, therefore, have classified the outstanding principal amount in current and long-term liabilities based on the timing of scheduled principal payments. As of March 31, 2023 and as of the date of the issuance of these financial statements, the Company was in compliance with all covenants and has not been notified of an event of default by the lender under the Loan Agreement. As of March 31, 2023, the carrying value of the term loan consists of $ 20.0 million principal outstanding less the debt discount and issuance costs of approximately $ 0.9 million. The End of Term Fee of $ 1.6 million is recognized over the life of the term loan as interest expense using the effective interest method. The debt issuance costs have been recorded as a debt discount which are being accreted to interest expense through the maturity date of the term loan. Interest expense relating to the term loan, which is included in interest expense in the condensed statements of operations and comprehensive loss, was $ 1.0 million and $ 0.8 million for the three months ended March 31, 2023 and 2022, respectively. Future principal payments for the long-term debt as of March 31, 2023 are as follows (in thousands): Amount 2023 (for the remaining 9 months) $ 10,063 2024 9,937 Total principal payments 20,000 End of term fee due at maturity in 2024 1,563 Total principal and end of term fee payments 21,563 Unamortized discount and debt issuance costs ( 882 ) Present value of remaining debt payments 20,681 Current portion of long-term debt ( 13,062 ) Long-term debt, net $ 7,619

Equity Financing

Equity Financing	3 Months Ended
	Mar. 31, 2023
Equity [Abstract]
Equity Financing	9. Equity Financing On October 19, 2022, the Company effected a reverse stock split of its outstanding share of common stock at a ratio of 1-for-10 pursuant to a Certificate of Amendment to the Company's Certificate of Incorporation filed with the Secretary of State of the State of Delaware. The reverse stock split was reflected on the Nasdaq Global Select Market beginning with the opening of trading on October 20, 2022. All share amounts and per share amounts disclosed in this Quarterly Report on Form 10-Q have been restated to reflect the reverse stock split on a retroactive basis in all periods presented. The Company has 10,000,000 shares of convertible preferred stock authorized for issuance, par value of $ 0.0001 per share. As of March 31, 2023 and December 31, 2022, no shares of preferred stock were issued and outstanding. The Company has 300,000,000 shares of common stock authorized for issuance, par value of $ 0.0001 per share. Holders of the Company’s common stock are entitled to one vote per share. As of March 31, 2023 and December 31, 2022, there were 14,359,214 and 14,215,302 shares, respectively, of common stock issued and outstanding. Follow-On Offering In August 2022, the Company closed an underwritten offering (the “Follow-On Offering”) in which the Company issued and sold an aggregate of 6,428,571 of the Company’s common stock together with warrants (the "Warrants”) to purchase up to 6,428,572 of the Company’s common stock at an offering price of at an aggregate offering price of $ 7.00 per unit. The Warrants have an exercise price of $ 8.50 per share underlying the Warrant. These Warrants were recorded as a component of stockholders’ equity within additional paid-in capital. The gross proceeds to the Company were $ 45.0 million before deducting underwriting discounts and commissions and other offering expenses. The net proceeds of the Follow-On Offering were approximately $ 41.7 million. The Warrants are exercisable at any time after their original issuance and on or prior to the five-year anniversary of the original issuance date. A holder of Warrants may not exercise the warrant if the holder, together with its affiliates, would beneficially own more than 4.99 % of the number of shares of common stock outstanding immediately after giving effect to such exercise. No warrants have been exercised as of March 31, 2023. At-the-Market Offering In March 2022, the Company filed a Registration Statement on Form S-3 (the “March 2022 Shelf Registration Statement”), covering the offering of up to $ 125.0 million of common stock, preferred stock, debt securities, warrants, and units, which was declared effective by the SEC in May 2022. In March 2022, the Company also entered into a sales agreement (the “March 2022 Sales Agreement”) with Cowen and Company, LLC ("Cowen") as sales agent to sell shares of the Company’s common stock, from time to time, with aggregate gross sales proceeds of up to $ 50.0 million pursuant to the March 2022 Shelf Registration Statement as an “at-the-market” offering under the Securities Act (the "March 2022 ATM Offering Program"). Cowen is entitled to up to 3.0 % of the gross proceeds of any shares of common stock sold under the March 2022 Sales Agreement. For so long as its public float is less than $75.0 million, it may not sell more than the equivalent of one-third of its public float during any 12 consecutive months pursuant to the "baby shelf" rules. During the three month period ended March 31, 2023, there were 106,781 shares of the Company's common stock sold pursuant to the March 2022 Sales Agreement and the Company received total net proceeds of approximately $ 0.4 million, after deducting commissions and other offering expenses which was insignificant. On August 17, 2022, the Company entered into Amendment No. 1 (the “Amendment”) to the March 2022 Sales Agreement, which Amendment decreased the amount of the Company’s common stock that can be sold by the Company through Cowen under the March 2022 Sales Agreement, from an aggregate offering of up to $ 50.0 million to an aggregate offering of up to $ 25.0 million. Following the Amendment, $ 15.2 million of shares of common stock remained available for sale under the March 2022 Sales Agreement, as amended, as of March 31, 2023. In October 2022, the Company filed a Registration Statement on Form S-3 (the “October 2022 Shelf Registration Statement”), covering the offering of up to $ 250.0 million of common stock, preferred stock, debt securities, warrants, and units. In October 2022, the Company also entered into a sales agreement (the “October 2022 Sales Agreement”) with Cowen as sales agent to sell shares of the Company’s common stock, from time to time, with aggregate gross sales proceeds of up to $ 50.0 million pursuant to the October 2022 Shelf Registration Statement as an “at-the-market” offering under the Securities Act. Cowen is entitled to up to 3.0 % of the gross proceeds of any shares of common stock sold under the October 2022 Sales Agreement. During the three months ended March 31, 2023, there were no shares of the Company's common stock sold pursuant to the October 2022 Sales Agreement. Equity Purchase Agreement In September 2021, the Company entered into an equity purchase agreement (the “Purchase Agreement” or “Equity Purchase Agreement”) and a registration rights agreement with Lincoln Park Capital Fund, LLC (“Lincoln Park” or “Investor”) which provides for the sale to Lincoln Park up to $ 30,000,000 of shares (the “Purchase Shares”) of its common stock over the thirty-six ( 36 ) month term of the Purchase Agreement. In connection with the Purchase Agreement, Lincoln Park purchased 102,040 Purchase Shares at a purchase price of $ 2.94 per share, for a total gross purchase price of $ 3.0 million (the “Initial Purchase”), and the Company issued 25,244 shares of common stock to Lincoln Park as a commitment fee in connection with entering into the Purchase Agreement. The Company recognized $ 0.8 million of other expense relating to the commitment fee share issuance. From the date of the agreement through December 31, 2022, the Company had initiated the purchase of an additional 380,000 shares of the Company’s common stock amounting to $ 6.2 million in gross proceeds. Under the Purchase Agreement, the Company has sole discretion, subject to certain conditions, on any business day selected by the Company to require Lincoln Park to purchase up to 10,000 shares of common stock (the “Regular Purchase Amount”) at the Purchase Price (as defined below) per purchase notice (each such purchase, a “Regular Purchase”). The Regular Purchase Amount may be increased as follows: up to 15,000 shares if the closing price is not below $ 35.00 , up to 20,000 shares if the closing price is not below $ 50.00 , and up to 25,000 shares if the closing price is not below $ 70.00 . Lincoln Park’s committed obligation under each Regular Purchase is capped at $ 2,000,000 , unless the Parties agree otherwise. The purchase price for Regular Purchases (the “Purchase Price”) shall be equal to the lesser of: (i) the lowest sale price of the common shares during the Purchase Date, or (ii) the average of the three (3) lowest closing sale prices of the common shares during the ten (10) business days prior to the Purchase Date. In addition to Regular Purchases and subject to certain conditions and limitations, the Company in its sole discretion may require Lincoln Park on each Purchase Date to purchase on the following business day up to the lesser of (i) three (3) times the number of shares purchased pursuant to such Regular Purchase or (ii) 30 % of the trading volume on the Accelerated Purchase Date (the “Accelerated Purchase”) (unless the Parties agree otherwise) at a purchase price equal to the lesser of 97 % of (i) the closing sale price on the Accelerated Purchase Date, or (ii) the Accelerated Purchase Date’s volume weighted average price (the “Accelerated Purchase Price”). The Company has the sole right to set a minimum price threshold for each Accelerated Purchase in the notice provided with respect to such Accelerated Purchase and under certain circumstances and in accordance with the Purchase Agreement the Company may direct multiple Accelerated Purchases in a day. The aggregate number of shares that the Company can sell to Lincoln Park under the Purchase Agreement may not exceed 1,106,580 shares of the common stock (which is equal to approximately 19.99 % of the shares of the common stock outstanding immediately prior to the execution of the Purchase Agreement) (the “Exchange Cap”), unless (i) shareholder approval is obtained to issue Purchase Shares above the Exchange Cap, in which the Exchange Cap will no longer apply, or (ii) the average price of all applicable sales of common stock to Lincoln Park under the Purchase Agreement equals or exceeds $ 29.40 per share; provided that at no time may Lincoln Park (together with its affiliates) beneficially own more than 9.99 % of the Company’s issued and outstanding common stock. The Purchase Agreement contains customary representations, warranties, covenants, closing conditions, indemnification and termination provisions. The Purchase Agreement may be terminated by the Company at any time, at its sole discretion, without any cost or penalty, by giving one business day notice to Lincoln Park. Further, Lincoln Park has covenanted not to engage in any direct or indirect short selling or hedging of the Common Shares. There are no limitations on the use of proceeds, financial or business covenants, restrictions on future financings (other than restrictions on the Company’s ability to enter into a similar type of agreement or Equity Line of Credit during the Term, excluding an At-The-Market transaction with a registered broker-dealer), rights of first refusal, participation rights, penalties or liquidated damages in the Purchase Agreement. Issuances under the Purchase Agreement were to be made pursuant to the Company's Registration Statement on Form S-3 filed in July 2019, which has since expired. The Company would need to file a new prospectus supplement covering issuances under the Purchase Agreement in order to continue using the facility.

Stock-Based Compensation

Stock-Based Compensation	3 Months Ended
	Mar. 31, 2023
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-Based Compensation	10 . Stock-Based Compensation Stock Options and Restricted Stock Units Activity A summary of the Company’s stock option activity under the 2013 Equity Incentive Plan, 2018 Incentive Award Plan, and 2020 Employment Inducement Incentive Plan for the three months ended March 31, 2023 is as follows: Number of Weighted- Balances at December 31, 2022 1,609,938 $ 27.51 Granted 9,000 $ 4.39 Canceled ( 14,980 ) $ 18.92 Balances at March 31, 2023 1,603,958 $ 27.46 A summary of the Company’s restricted stock units (“RSUs”), performance stock units (“PSUs”), and restricted stock awards (“RSAs”) activity for the three months ended March 31, 2023 is as follows: Number of Weighted- Unvested at December 31, 2022 146,333 $ 27.66 Granted — $ — Vested ( 37,131 ) $ 28.83 Canceled ( 750 ) $ 10.60 Unvested at March 31, 2023 108,452 $ 27.37 For stock options granted to employees with service-based vesting, the fair value of stock options granted to employees was estimated on the date of grant using the Black-Scholes option pricing model and utilizing assumptions that were determined as follows: Expected Term —The expected term represents the period that the options granted are expected to be outstanding and is determined using the simplified method (based on the mid-point between the vesting date and the end of the contractual term) as the Company has concluded that its stock option exercise history does not provide a reasonable basis upon which to estimate expected term. Expected Volatility —Due to limited historical data, the Company estimates stock price volatility based on a combined weighted-average of the Company’s historical average volatility and that of a selected peer group of comparable publicly traded companies within the biotechnology and pharmaceutical industry that were deemed to be representative of future stock price trends over the expected life of the award. Risk-Free Interest Rate —The Company based the risk-free interest rate over the expected term of the options based on the constant maturity rate of U.S. Treasury securities with similar maturities as of the date of the grant. Expected Dividends —The Company has never paid any dividends and does not plan to pay dividends in the foreseeable future. Therefore, the expected dividend yield is zero. Stock Based Compensation Expense The following table sets forth the total stock-based compensation expense for all options granted to employees and nonemployees, including shares sold through the issuance of non-recourse promissory notes which are considered to be options for accounting purposes, and costs associated with the Company’s 2018 Employee Stock Purchase Plan (“2018 ESPP”) included in the Company’s condensed statements of operations and comprehensive loss (in thousands): Three Months Ended March 31, 2023 2022 Research and development $ 757 $ 1,004 General and administrative 1,513 1,656 Total $ 2,270 $ 2,660

Net Loss per Common Share

Net Loss per Common Share	3 Months Ended
	Mar. 31, 2023
Earnings Per Share [Abstract]
Net Loss per Common Share	11. Net Loss per Common Share Basic net loss per share is calculated by dividing net loss by the weighted-average number of shares outstanding for the period. Diluted net loss per share is calculated by dividing net loss by the weighted-average number of shares of common stock and potential dilutive common stock equivalents outstanding during the period if the effect is dilutive. The calculation of diluted earnings (loss) per share also requires that, to the extent contingencies are satisfied during the period and the presumed issuance of additional shares as contingent consideration is dilutive to earnings (loss) per share for the period, adjustments to net income or net loss used in the calculation are required to remove the change in fair value of the contingent consideration liability for the period. Likewise, adjustments to the denominator are required to reflect the related dilutive shares. In all periods presented, the Company’s outstanding stock options, RSUs (including PSUs), early exercised common stock subject to future vesting, restricted stock accounted for as options, shares subject to the 2018 ESPP and presumed issuance of additional shares as contingent consideration were excluded from the calculation of diluted net loss per share because their effects were antidilutive. A reconciliation of the numerators and denominators used in computing net loss from continuing operations per share is as follows (in thousands, except share and per share amounts): Three Months Ended March 31, 2023 2022 Numerator: Net loss $ ( 10,865 ) $ ( 18,915 ) Denominator: Weighted-average number of shares 14,312,887 6,752,855 Net loss per share—basic and diluted $ ( 0.76 ) $ ( 2.80 ) Since the Company was in a net loss position for all periods presented, basic net loss per common share is the same as diluted net loss per common share as the inclusion of all potential common shares outstanding would have been anti-dilutive. Potentially dilutive securities that were not included in the diluted per share calculations because they would be anti-dilutive were as follows: Three Months Ended March 31, 2023 2022 Options to purchase common stock 1,603,958 984,677 Outstanding warrants to purchase common stock 6,428,572 — Early exercised common stock subject to future vesting 3,336 3,336 RSUs 108,452 199,835 Shares subject to 2018 ESPP 65,939 14,501 Total 8,210,257 1,202,349 Up to 3,390 shares may be contingently issued, if certain performance conditions are met under the Company’s in-licensing agreements.

Defined Contribution Plan

Defined Contribution Plan	3 Months Ended
	Mar. 31, 2023
Compensation And Retirement Disclosure [Abstract]
Defined Contribution Plan	12. Defined Contribution Plan The Company sponsors a 401(k) Plan that stipulates that eligible employees can elect to contribute to the 401(k) Plan, subject to certain limitations, on a pretax basis. In January 2019, the Company began to match 4 % of employees’ salary. During the three months ended March 31, 2023 and 2022, the Company recorded matching contributions of $ 0.1 million and $ 0.2 million, respectively.

Subsequent Events

Subsequent Events	3 Months Ended
	Mar. 31, 2023
Subsequent Events [Abstract]
Subsequent Events	13. Subsequent Events On May 4, 2023 , the Company implemented a reduction in its workforce to align operations with the changes in its corporate strategy to focus on resource optimization to enable the initiation and achievement of key data readouts. The reduction is expected to decrease its headcount by nine employees, or approximately 29 % of the Company’s workforce, effective as of May 31, 2023 with three employees departing as of June 30, 2023. The Company will incur a one-time employee benefits and severance charge of approximately $ 0.8 million in operating expenses in the first half of 2023. On May 4, 2023, the Company’s Board of Directors approved a stock option repricing for employees and service providers that were not affected by the reduction in its workforce, as well as employees subject to a continuing consulting agreement, as of May 11, 2023, where the exercise price of each outstanding option to purchase shares of the Company's common stock granted under its 2018 Incentive Award Plan had an original exercise price above $ 6.00 , by reducing the exercise price to the closing price for the Company's common stock on May 11, 2023, the effective date of the reduction.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2023
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation These condensed financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) and the rules and regulations of the United States Securities and Exchange Commission (“SEC”) for interim reporting. Certain information and footnote disclosures normally included in annual financial statements prepared in accordance with GAAP have been condensed or omitted. Accordingly, the unaudited condensed financial statements should be read in conjunction with the audited financial statements and the related notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2022 filed with the SEC. The Company effected a reverse stock split on October 19, 2022 of its outstanding shares of common stock at a ratio of 1-for-10 pursuant to a Certificate of Amendment to the Company's Certificate of Incorporation filed with the Secretary of State of the State of Delaware. The reverse stock split was reflected on the Nasdaq Global Select Market beginning with the opening of trading on October 20, 2022. The reverse stock split did not change the par value of the Company's common stock or the authorized number of shares of the Company's common stock. All share amounts and per share amounts disclosed in this Quarterly Report on Form 10-Q have been restated to reflect the reverse stock split on a retroactive basis in all periods presented.
Unaudited Condensed Financial Statements	Unaudited Condensed Financial Statements The accompanying financial information for the three months ended March 31, 2023 and 2022 are unaudited. The unaudited condensed financial statements have been prepared on the same basis as the annual audited financial statements and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary to present fairly the Company’s financial position as of March 31, 2023 and its results of operations for the three months ended March 31, 2023 and 2022 and cash flows for the three months ended March 31, 2023 and 2022. The results for interim periods are not necessarily indicative of the results expected for the full fiscal year or any other periods.
Use of Estimates	Use of Estimates The condensed financial statements have been prepared in accordance with GAAP, which requires management to make estimates and assumptions that affect the amounts and disclosures reported in the condensed financial statements and accompanying notes. The Company bases its estimates on historical experience and market-specific or other relevant assumptions that it believes are reasonable under the circumstances. The amounts of assets and liabilities reported in the Company’s condensed balance sheets and the amount of expenses and income reported for each of the periods presented are affected by estimates and assumptions, which are used for, but are not limited to, determining the fair value of assets and liabilities, the fair value of right-of-use assets and lease liabilities, and stock-based compensation. Actual results could differ from such estimates or assumptions.
Segments	Segments The Company has one operating segment. The Company’s chief operating decision maker, its Chief Executive Officer, manages the Company’s operations on a consolidated basis for the purposes of allocating resources.
Recently Adopted Accounting Pronouncements	Recently Adopted Accounting Pronouncements In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments—Credit Losses (Topic 326) , Measurement of Credit Losses on Financial Instruments , as clarified in subsequent amendments. ASU 2016-13 changes the impairment model for certain financial instruments. The new model is a forward-looking expected loss model and will apply to financial assets subject to credit losses and measured at amortized cost and certain off-balance sheet credit exposures. This includes loans, held-to-maturity debt securities, loan commitments, financial guarantees and net investments in leases, as well as trade receivables. For available-for-sale debt securities with unrealized losses, credit losses will be measured in a manner similar to today, except that the losses will be recognized as allowances rather than reductions in the amortized cost of the securities. In October 2019, the FASB voted to delay the effective date of this standard. Topic 326 will be effective for the Company for fiscal years beginning after December 15, 2022. Early adoption is permitted. We adopted ASU 2016-13 on January 1, 2023 and the adoption did no t have a material impact on the Company’s condensed consolidated financial statements and related disclosures. In November 2021, the FASB issued ASU 2021-10, Government Assistance, or Topic 832, which requires enhanced disclosures of transactions with governments that are accounted for by applying a grant or contribution model. The new pronouncement requires entities to provide information about the nature of the transaction, terms and conditions associated with the transaction and financial statement line items affected by the transaction. The Company adopted the standard for the annual period beginning January 1, 2023 . The employee retention credit received under the CARES Act qualifies as a government assistance program under Topic 832 and resulted in enhanced required disclosures, as described in Note 6.
Fair Value Measurements	The Company determines the fair value of financial and non-financial assets and liabilities based on the assumptions that market participants would use in pricing the asset or liability in an orderly transaction between market participants at the measurement date. The identification of market participant assumptions provides a basis for determining what inputs are to be used for pricing each asset or liability. A fair value hierarchy has been established which gives precedence to fair value measurements calculated using observable inputs over those using unobservable inputs. This hierarchy prioritized the inputs into three broad levels as follows: • Level 1: Quoted prices in active markets for identical instruments • Level 2: Other significant observable inputs (including quoted prices in active markets for similar instruments) • Level 3: Significant unobservable inputs (including assumptions in determining the fair value of certain investments) The Company estimates the fair value of its money market funds, certificates of deposits, U.S. and foreign commercial paper, U.S. and foreign corporate debt securities, U.S. treasuries, and U.S. government debt securities by taking into consideration valuations obtained from third-party pricing services. Based upon the Company's intent and ability to hold its certificates of deposit to maturity, such securities have been classified as held-to-maturity and are carried at amortized cost, which approximates market value. The pricing services utilize industry standard valuation models, including both income and market-based approaches, for which all significant inputs are observable, either directly or indirectly, to estimate fair value. These inputs include reported trades of and broker/dealer quotes on the same or similar securities, issuer credit spreads; benchmark securities; prepayment/default projections based on historical data; and other observable inputs.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2023
Fair Value Disclosures [Abstract]
Summary of Financial Assets and Liabilities Subject to Fair Value Measurements on Recurring Basis and Level of Inputs Used in Measurements	The Company’s financial assets and liabilities subject to fair value measurements on a recurring basis and the level of inputs used in such measurements were as follows (in thousands): March 31, 2023 Total Level 1 Level 2 Level 3 Assets: Cash equivalents: Money market funds $ 18,910 $ 18,910 $ — $ — Long-term certificates of deposits 896 — 896 — Total cash equivalents 19,806 18,910 896 — Short-term marketable securities: U.S. and foreign commercial paper — — — — U.S. and foreign corporate debt securities — — — — U.S. treasuries 8,728 — 8,728 — U.S. government debt securities 51,692 — 51,692 — Total short-term marketable securities 60,420 — 60,420 — Total assets subject to fair value measurements $ 80,226 $ 18,910 $ 61,316 $ — December 31, 2022 Total Level 1 Level 2 Level 3 Assets: Cash equivalents: Money market funds $ 5,083 $ 5,083 $ — $ — Total cash equivalents 5,083 5,083 — — Short-term marketable securities: U.S. treasuries 30,758 — 30,758 — U.S. government debt securities 51,301 — 51,301 — Total short-term marketable securities 82,059 — 82,059 — Total assets subject to fair value measurements $ 87,142 $ 5,083 $ 82,059 $ —

Marketable Securities (Tables)

Marketable Securities (Tables)	3 Months Ended
	Mar. 31, 2023
Investments Debt And Equity Securities [Abstract]
Summary of Marketable Securities Classified as Available-for-Sale	Marketable securities, which are classified as available-for-sale, consisted of the following as of March 31, 2023, (in thousands): Amortized Unrealized Unrealized Fair Cash equivalents: Money market funds $ 18,910 $ — $ — $ 18,910 Total cash equivalents 18,910 — — 18,910 Short-term marketable securities: U.S. treasuries 8,734 — ( 6 ) 8,728 U.S. government debt securities 51,836 13 ( 157 ) 51,692 Total short-term marketable securities 60,570 13 ( 163 ) 60,420 Total $ 79,480 $ 13 $ ( 163 ) $ 79,330 Marketable securities, which are classified as available-for-sale, consisted of the following as of December 31, 2022 (in thousands): Amortized Unrealized Unrealized Fair Cash equivalents: Money market funds $ 5,083 $ — $ — $ 5,083 Total cash equivalents 5,083 — — 5,083 Short-term marketable securities: U.S. treasuries 30,820 1 ( 63 ) 30,758 U.S. government debt securities 51,491 6 ( 196 ) 51,301 Total short-term marketable securities 82,311 7 ( 259 ) 82,059 Total $ 87,394 $ 7 $ ( 259 ) $ 87,142

Commitments and Contingencies (

Commitments and Contingencies (Tables)	3 Months Ended
	Mar. 31, 2023
Commitments And Contingencies Disclosure [Abstract]
Summary of Components of Lease Expense	The following table summarizes the components of lease expense, which are included in operating expenses in the Company’s condensed statements of operations and comprehensive loss (in thousands): Three Months Ended March 31, 2023 2022 Operating lease cost $ 930 $ 1,078 Variable lease cost 203 296 Sublease income ( 963 ) ( 1,048 ) Total lease cost $ 170 $ 326
Summary of Supplemental Information Related to Leases	The following table summarizes supplemental information related to leases (in thousands): Three Months Ended March 31, 2023 2022 Cash paid for amounts included in the measurement of lease liabilities Operating cash flows from operating leases $ 1,200 $ 1,704 Weighted-average remaining lease term (years) Operating leases 6.8 7.8 Weighted-average discount rate (percentage) Operating leases 6.0 % 6.0 %
Summary of Maturities of Lease Liabilities	The following table summarizes the maturities of lease liabilities as of March 31, 2023 (in thousands): Amount 2023 (remaining 9 months) $ 3,610 2024 4,964 2025 5,123 2026 5,287 2027 5,457 Thereafter 11,435 Total future minimum lease payments 35,876 Less: Amount representing interest ( 6,540 ) Present value of future minimum lease payments 29,336 Less: Current portion of operating lease liability ( 3,186 ) Noncurrent portion of operating lease liability $ 26,150

Term Loan Facility (Tables)

Term Loan Facility (Tables)	3 Months Ended
	Mar. 31, 2023
Debt Disclosure [Abstract]
Schedule of Future Principal Payments for Long-Term Debt	Future principal payments for the long-term debt as of March 31, 2023 are as follows (in thousands): Amount 2023 (for the remaining 9 months) $ 10,063 2024 9,937 Total principal payments 20,000 End of term fee due at maturity in 2024 1,563 Total principal and end of term fee payments 21,563 Unamortized discount and debt issuance costs ( 882 ) Present value of remaining debt payments 20,681 Current portion of long-term debt ( 13,062 ) Long-term debt, net $ 7,619

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2023
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Stock Option Activity	A summary of the Company’s stock option activity under the 2013 Equity Incentive Plan, 2018 Incentive Award Plan, and 2020 Employment Inducement Incentive Plan for the three months ended March 31, 2023 is as follows: Number of Weighted- Balances at December 31, 2022 1,609,938 $ 27.51 Granted 9,000 $ 4.39 Canceled ( 14,980 ) $ 18.92 Balances at March 31, 2023 1,603,958 $ 27.46
Summary of Restricted Stock Units, Performance Stock Units and Restricted Stock Awards Activity	A summary of the Company’s restricted stock units (“RSUs”), performance stock units (“PSUs”), and restricted stock awards (“RSAs”) activity for the three months ended March 31, 2023 is as follows: Number of Weighted- Unvested at December 31, 2022 146,333 $ 27.66 Granted — $ — Vested ( 37,131 ) $ 28.83 Canceled ( 750 ) $ 10.60 Unvested at March 31, 2023 108,452 $ 27.37
Summary of Stock-based Compensation Expense	The following table sets forth the total stock-based compensation expense for all options granted to employees and nonemployees, including shares sold through the issuance of non-recourse promissory notes which are considered to be options for accounting purposes, and costs associated with the Company’s 2018 Employee Stock Purchase Plan (“2018 ESPP”) included in the Company’s condensed statements of operations and comprehensive loss (in thousands): Three Months Ended March 31, 2023 2022 Research and development $ 757 $ 1,004 General and administrative 1,513 1,656 Total $ 2,270 $ 2,660

Net Loss per Common Share (Tabl

Net Loss per Common Share (Tables)	3 Months Ended
	Mar. 31, 2023
Earnings Per Share [Abstract]
Schedule of Reconciliation of Numerators and Denominators Used In Computing Net Loss From Continuing Operations Per Share	A reconciliation of the numerators and denominators used in computing net loss from continuing operations per share is as follows (in thousands, except share and per share amounts): Three Months Ended March 31, 2023 2022 Numerator: Net loss $ ( 10,865 ) $ ( 18,915 ) Denominator: Weighted-average number of shares 14,312,887 6,752,855 Net loss per share—basic and diluted $ ( 0.76 ) $ ( 2.80 )
Summary of Potentially Dilutive Securities Excluded from Computation of Diluted Per Share	Potentially dilutive securities that were not included in the diluted per share calculations because they would be anti-dilutive were as follows: Three Months Ended March 31, 2023 2022 Options to purchase common stock 1,603,958 984,677 Outstanding warrants to purchase common stock 6,428,572 — Early exercised common stock subject to future vesting 3,336 3,336 RSUs 108,452 199,835 Shares subject to 2018 ESPP 65,939 14,501 Total 8,210,257 1,202,349

Organization - Additional Infor

Organization - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022	[1]
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Accumulated deficit	$ (470,816)		$ (459,951)
Net loss	(10,865)	$ (18,915)
Cash used in operations	(11,316)	(14,972)
Product revenue	0	$ 0
Cash, cash equivalents and marketable securities	$ 83,400
Substantial doubt about going concern, within one year [true false]	true
Percentage of reduction in force	29%
[1] The balance sheet as of December 31, 2022 is derived from the audited financial statements as of that date.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies - Additional Information (Details)		3 Months Ended
	Oct. 19, 2022	Mar. 31, 2023 Segment
Reverse stock split ratio	0.1
Number of operating segment		1
ASU 2016-13
Change in accounting principle, accounting standards update, adopted [true false]		true
Accounting standards, adoption date		Jan. 01, 2023
Change in accounting principle, accounting standards update, immaterial effect [true false]		false
ASU 2021-10
Change in accounting principle, accounting standards update, adopted [true false]		true
Accounting standards, adoption date		Jan. 01, 2023

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Financial Assets and Liabilities Subject to Fair Value Measurements on Recurring Basis and Level of Inputs Used in Measurements (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Assets:
Short-term marketable securities	$ 60,420	$ 82,059	[1]
Fair Value, Recurring
Assets:
Cash equivalents	19,806	5,083
Short-term marketable securities	60,420	82,059
Total assets subject to fair value measurements on a recurring basis	80,226	87,142
Fair Value, Recurring | Level 1
Assets:
Cash equivalents	18,910	5,083
Total assets subject to fair value measurements on a recurring basis	18,910	5,083
Fair Value, Recurring | Level 2
Assets:
Cash equivalents	896
Short-term marketable securities	60,420	82,059
Total assets subject to fair value measurements on a recurring basis	61,316	82,059
Money market funds | Fair Value, Recurring
Assets:
Cash equivalents	18,910	5,083
Money market funds | Fair Value, Recurring | Level 1
Assets:
Cash equivalents	18,910	5,083
Long-term certificates of deposits | Fair Value, Recurring
Assets:
Cash equivalents	896
Long-term certificates of deposits | Fair Value, Recurring | Level 2
Assets:
Cash equivalents	896
U.S. Treasuries | Fair Value, Recurring
Assets:
Short-term marketable securities	8,728	30,758
U.S. Treasuries | Fair Value, Recurring | Level 2
Assets:
Short-term marketable securities	8,728	30,758
U.S. government debt securities | Fair Value, Recurring
Assets:
Short-term marketable securities	51,692	51,301
U.S. government debt securities | Fair Value, Recurring | Level 2
Assets:
Short-term marketable securities	$ 51,692	$ 51,301
[1] The balance sheet as of December 31, 2022 is derived from the audited financial statements as of that date.

Marketable Securities - Summary

Marketable Securities - Summary of Marketable Securities Classified as Available-for-Sale (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost Basis	$ 79,480	$ 87,394
Unrealized Gains	13	7
Unrealized Losses	(163)	(259)
Fair Value	79,330	87,142
Cash Equivalents
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost Basis	18,910	5,083
Unrealized Gains	0	0
Unrealized Losses	0	0
Fair Value	18,910	5,083
Cash Equivalents | Money market funds
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost Basis	18,910	5,083
Unrealized Gains	0	0
Unrealized Losses	0	0
Fair Value	18,910	5,083
Short Term Marketable Securities
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost Basis	60,570	82,311
Unrealized Gains	13	7
Unrealized Losses	(163)	(259)
Fair Value	60,420	82,059
Short Term Marketable Securities | U.S. government debt securities
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost Basis	51,836	51,491
Unrealized Gains	13	6
Unrealized Losses	(157)	(196)
Fair Value	51,692	51,301
Short Term Marketable Securities | U S Treasuries
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost Basis	8,734	30,820
Unrealized Gains	0	1
Unrealized Losses	(6)	(63)
Fair Value	$ 8,728	$ 30,758

Marketable Securities - Additio

Marketable Securities - Additional Information (Details) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2023	Dec. 31, 2022
Marketable Securities [Line Items]
Realized gains or losses on available-for-sale debt securities	$ 0	$ 0
Maximum
Marketable Securities [Line Items]
Available-for sale securities, remaining contractual maturity	1 year

License Revenue and Agreements

License Revenue and Agreements - Additional Information (Details) - USD ($)	1 Months Ended	3 Months Ended		12 Months Ended
	Jun. 30, 2019	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2021	Dec. 31, 2022
Research And Development Arrangement Contract To Perform For Others [Line Items]
Common stock, shares issued		14,359,214			14,215,302
Ascentage Pharma
Research And Development Arrangement Contract To Perform For Others [Line Items]
Compound library and option agreement execution month and year		2016-02
Compound library and option agreement expiration month and year		2022-02
Ascentage Pharma | Licensed Products
Research And Development Arrangement Contract To Perform For Others [Line Items]
Royalties due from sales		$ 0
License Agreement | Jocasta Neuroscience Inc
Research And Development Arrangement Contract To Perform For Others [Line Items]
Upfront cash payments received				$ 5,000,000
Revenue recognized		0	$ 0
Deferred revenue		0			$ 0
Other Licensing Agreements with Research Institutions
Research And Development Arrangement Contract To Perform For Others [Line Items]
Contingent consideration, milestone or royalty payments		0	$ 0
Other Licensing Agreements with Research Institutions | UCSF
Research And Development Arrangement Contract To Perform For Others [Line Items]
Common shares expected to be issued	3,400
Contingent consideration, milestone or royalty payments		$ 0
Maximum milestone payments for each product licensed under agreement	$ 13,600,000
Commercial Agreements | Ascentage Pharma
Research And Development Arrangement Contract To Perform For Others [Line Items]
Equity payments percentage		80%
Common stock, shares issued		0
Commercial Agreements | Ascentage Pharma | Maximum
Research And Development Arrangement Contract To Perform For Others [Line Items]
Contingent consideration additional common stock issued for one licensed product		93,333
Contingent consideration additional common stock issued for two or more licensed product		133,333
Milestone payments		$ 70,300,000
Commercial Agreements | Ascentage Pharma | Initial License Agreement
Research And Development Arrangement Contract To Perform For Others [Line Items]
License agreement termination month and year		2020-07
License agreement execution month and year		2016-02
Commercial Agreements | Ascentage Pharma | Second License Agreement
Research And Development Arrangement Contract To Perform For Others [Line Items]
License agreement execution month and year		2019-01
Commercial Agreements | Affiliate of Clinical-Stage Biopharmaceutical Company
Research And Development Arrangement Contract To Perform For Others [Line Items]
Equity payments percentage		20%

Government Assistance Program -

Government Assistance Program - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Government Assistance [Line Items]
Employee retention credit receivable	$ 1.5	$ 0
CARES Act Member
Government Assistance [Line Items]
Refundable employee retention credit	1.5
Contra-expense to personnel related cost		$ 0
General And Administrative Expense | CARES Act Member
Government Assistance [Line Items]
Contra-expense to personnel related cost	0.4
Research And Development Expense | CARES Act Member
Government Assistance [Line Items]
Contra-expense to personnel related cost	$ 1.1

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details)	1 Months Ended		3 Months Ended
	May 31, 2022 USD ($) ft² $ / ft²	Jun. 30, 2021 USD ($) ft² $ / ft²	Mar. 31, 2023 USD ($)	Mar. 31, 2022 USD ($)	Feb. 28, 2019 USD ($)	May 31, 2016 USD ($)
Commitments And Contingencies [Line Items]
Sublease income			$ 963,000	$ 1,048,000
South San Francisco, California
Commitments And Contingencies [Line Items]
Lessee, operating lease, description			In February 2019, the Company entered into a lease agreement for new office and laboratory space in South San Francisco, California. The term of the lease agreement commenced in May 2019. The lease has an initial term from occupancy of approximately ten years ending on December 31, 2029 with an option to extend the term for an additional eight years at then-market rental rates
Operating lease, initial lease term			10 years
Operating lease, renewal term			8 years
Tenant improvement allowance					$ 10,700,000
Letter of credit, delivered in connection of lease agreement			$ 900,000
Lease commencement date			2019-05
Operating lease, option to extend description			option to extend the term for an additional eight years
Operating lease, existence of option to extend			true
Lease expiration date			Dec. 31, 2029
South San Francisco, California | Office and Laboratory Space, Second Floor
Commitments And Contingencies [Line Items]
Impairment loss			$ 0	0
Space subleased (in square feet) | ft²	15,000
Sublease start date	Jul. 01, 2022
Sublease expiration date	Jun. 30, 2024
Sublease rent per square foot | $ / ft²	7.80
Annual percentage increase in sublease base rent	3.50%
Percentage of operating expenses and property management fees to be paid by subtenant	24%
Incurred initial direct costs of sublease	$ 100,000
Sublease income			400,000	0
South San Francisco, California | Office And Laboratory Space First Floor
Commitments And Contingencies [Line Items]
Impairment loss			0	0
Space subleased (in square feet) | ft²		23,000
Sublease expiration date		Aug. 31, 2024
Sublease rent per square foot | $ / ft²		6.25
Annual percentage increase in sublease base rent		3.50%
Percentage of operating expenses and property management fees to be paid by subtenant		37%
Incurred initial direct costs of sublease		$ 200,000
Sublease income			$ 600,000	$ 600,000
Brisbane, California
Commitments And Contingencies [Line Items]
Operating lease, renewal term			4 years
Tenant improvement allowance						$ 3,900,000
Lease commencement date			2016-05
Operating lease, option to extend description			The lease agreement includes an escalation clause for increased rent and a renewal provision allowing the Company to extend this lease for an additional four years by giving the landlord written notice of the election to exercise the option at least fifteen months prior to the original expiration of the lease term.
Lease expiration date			2022-10

Commitments and Contingencies_2

Commitments and Contingencies - Summary of Components of Lease Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Lease, Cost [Abstract]
Operating lease cost	$ 930	$ 1,078
Variable lease cost	203	296
Sublease income	(963)	(1,048)
Total lease cost	$ 170	$ 326

Commitments and Contingencies_3

Commitments and Contingencies - Summary of Supplemental Information Related to Leases (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Commitments And Contingencies Disclosure [Abstract]
Operating cash flows from operating leases	$ 1,200	$ 1,704
Operating leases, Weighted-average remaining lease term (years)	6 years 9 months 18 days	7 years 9 months 18 days
Operating leases, Weighted-average discount rate (percentage)	6%	6%

Commitments and Contingencies_4

Commitments and Contingencies - Summary of Maturities of Lease Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022	[1]
Commitments And Contingencies Disclosure [Abstract]
2023 (remaining 9 months)	$ 3,610
2024	4,964
2025	5,123
2026	5,287
2027	5,457
Thereafter	11,435
Total future minimum lease payments	35,876
Less: Amount representing interest	(6,540)
Present value of future minimum lease payments	29,336
Less: Current portion of operating lease liability	(3,186)
Noncurrent portion of operating lease liability	$ 26,150	$ 26,991
[1] The balance sheet as of December 31, 2022 is derived from the audited financial statements as of that date.

Term Loan Facility - Additional

Term Loan Facility - Additional Information (Details) $ in Thousands				2 Months Ended	3 Months Ended		12 Months Ended
	Dec. 31, 2021 USD ($)	Dec. 15, 2021 USD ($)	Aug. 03, 2020 USD ($) Tranche	Feb. 14, 2022 USD ($)	Mar. 31, 2023 USD ($)	Mar. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2022 USD ($)	[1]	Jul. 01, 2021 USD ($)
Debt Instrument [Line Items]
Debt instrument aggregate principal amount					$ 20,000
Outstanding principal converted to equity					7,619			$ 10,891
Unamortized discount and debt issuance costs					882
End of term fee due at maturity					1,563
Interest expense					1,002	$ 808
Term Loan | Loan Agreement | Hercules Capital
Debt Instrument [Line Items]
Debt instrument aggregate principal amount					$ 20,000
Number of tranches | Tranche			4
Principal amount of first tranche			$ 25,000			20,000
Long-term debt, maturity date					Aug. 01, 2024
Debt conversion, original debt amount	$ 2,300	$ 5,000		$ 5,000		2,700
Loan issuance cost							$ 100
Final payment fee of the total term loan advanced					6.25%
Debt instrument, interest rate terms					Interest on the term loan accrues at a per annum rate equal to the greater of (i) the Wall Street Journal prime rate plus 6.10% and (ii) 9.35%. On March 31, 2023, the interest rate on the term loan was 14.10%. Interest expense is calculated using the effective interest method and is inclusive of non-cash amortization of capitalized loan issuance costs. At March 31, 2023, the effective interest rate was 20.37%.
Debt instrument, interest rate, stated percentage					14.10%
Debt instrument, interest rate, effective percentage					20.37%
Maximum amount of debt that can be purchased by lender.					$ 2,000
Debt instrument, unrestricted cash										$ 15,000
Debt instrument, minimum unrestricted cash		$ 10,000
Unamortized discount and debt issuance costs					900
End of term fee due at maturity					1,600
Term Loan | Loan Agreement | Hercules Capital | Interest And Other Expense
Debt Instrument [Line Items]
Interest expense					$ 1,000	$ 800
Term Loan | Loan Agreement | Hercules Capital | Wall Street Journal Prime Rate
Debt Instrument [Line Items]
Debt instrument, interest rate, basis spread on variable rate					6.10%
Term Loan | Loan Agreement | Hercules Capital | Maximum
Debt Instrument [Line Items]
Debt instrument aggregate principal amount			$ 80,000
Loan amendment conversion effective month of anniversary		6 months
Debt conversion, original debt amount		$ 5,000
Debt conversion percentage of principal amount		20%
Prepayment fee					1.50%
Term Loan | Loan Agreement | Hercules Capital | Minimum
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage					9.35%
[1] The balance sheet as of December 31, 2022 is derived from the audited financial statements as of that date.

Term Loan Facility - Schedule o

Term Loan Facility - Schedule of Future Principal Payments for Long-Term Debt (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022	[1]
Debt Disclosure [Abstract]
2023 (for the remaining 9 months)	$ 10,063
2024	9,937
Total principal payments	20,000
End of term fee due at maturity in 2024	1,563
Total principal and end of term fee payments	21,563
Unamortized discount and debt issuance costs	(882)
Present value of remaining debt payments	20,681
Current portion of long-term debt	(13,062)	$ (9,476)
Long-term debt, net	$ 7,619	$ 10,891
[1] The balance sheet as of December 31, 2022 is derived from the audited financial statements as of that date.

Equity Financing - Additional I

Equity Financing - Additional Information (Details)

1 Months Ended

3 Months Ended

9 Months Ended

12 Months Ended

Oct. 19, 2022

Aug. 31, 2022 USD ($) $ / shares shares

Aug. 17, 2022 USD ($)

Oct. 31, 2022 USD ($)

Mar. 31, 2022 USD ($) shares

Sep. 30, 2021 USD ($) $ / shares shares

Sep. 30, 2020 $ / shares

Mar. 31, 2023 USD ($) $ / shares shares

Mar. 31, 2022 USD ($) shares

Sep. 30, 2021 USD ($) $ / shares shares

Dec. 31, 2022 USD ($) $ / shares shares

Dec. 31, 2021 shares

[1]

Subsidiary Sale Of Stock [Line Items]

Reverse stock split ratio

0.1

Number of stock, authorized for issuance

10,000,000

10,000,000

Number of stock, par value per share | $ / shares

$ 0.0001

$ 0.0001

Number of stock, shares issued

0

0

Number of stock, shares outstanding

0

0

Common stock, shares authorized

300,000,000

300,000,000

Common stock, par value per share | $ / shares

$ 0.0001

$ 0.0001

Common stock, shares issued

14,359,214

14,215,302

Common stock, shares outstanding

14,359,214

14,215,302

Equity financing, authorized amount | $

$ 250,000,000

$ 125,000,000

Common Stock

Subsidiary Sale Of Stock [Line Items]

Common stock, shares outstanding

6,914,777

[1]

14,359,214

6,914,777

[1]

14,215,302

6,299,158

March 2022 ATM Offering Program | Common Stock | Cowen | March 2022 Sales Agreement

Subsidiary Sale Of Stock [Line Items]

Percentage of gross sales proceeds of common stock payable as compensation

3%

Issuance of common stock (in shares)

106,781

Proceeds from sale of common stock | $

$ 400,000

March 2022 ATM Offering Program | Common Stock | Cowen | March 2022 Sales Agreement | Maximum

Subsidiary Sale Of Stock [Line Items]

Equity financing, authorized amount | $

$ 50,000,000

$ 50,000,000

March 2022 ATM Offering Program Amendment | March 2022 Sales Agreement

Subsidiary Sale Of Stock [Line Items]

Common stock amount remained available for sale | $

$ 15,200,000

March 2022 ATM Offering Program Amendment | Common Stock | Cowen | March 2022 Sales Agreement | Maximum

Subsidiary Sale Of Stock [Line Items]

Equity financing, authorized amount | $

$ 25,000,000

October 2022 At The Market Equity Offering Program | Cowen | October 2022 Sales Agreement

Subsidiary Sale Of Stock [Line Items]

Percentage of gross sales proceeds of common stock payable as compensation

3%

Issuance of common stock (in shares)

0

October 2022 At The Market Equity Offering Program | Cowen | October 2022 Sales Agreement | Maximum

Subsidiary Sale Of Stock [Line Items]

Equity financing, authorized amount | $

$ 50,000,000

Equity Purchase Agreement | Lincoln Park Capital Fund LLC

Subsidiary Sale Of Stock [Line Items]

Issuance of common stock (in shares)

102,040

380,000

Issuance of common stock, value | $

$ 910,000

Purchase agreement term

36 months

Share purchase price | $ / shares

$ 2.94

$ 2.94

Total gross purchase price of share | $

$ 3,000,000

Regular purchase capped amount | $

$ 2,000,000

Percentage of trading volume

30%

Percentage of purchase price

97%

Percentage of shares issued to common shares outstanding immediately prior to the execution of the purchase agreement.

19.99%

Purchase agreement price per share | $ / shares

$ 29.40

$ 29.40

Maximum percentage ownership of issued and outstanding shares

9.99%

Equity Purchase Agreement | Lincoln Park Capital Fund LLC | Purchase Agreement 35.00 Closing Price

Subsidiary Sale Of Stock [Line Items]

Regular purchase amount closing price per share | $ / shares

$ 35

Equity Purchase Agreement | Lincoln Park Capital Fund LLC | Purchase Agreement 50.00 Closing Price

Subsidiary Sale Of Stock [Line Items]

Regular purchase amount closing price per share | $ / shares

$ 50

Equity Purchase Agreement | Lincoln Park Capital Fund LLC | Purchase Agreement 70.00 Closing Price

Subsidiary Sale Of Stock [Line Items]

Regular purchase amount closing price per share | $ / shares

$ 70

Equity Purchase Agreement | Lincoln Park Capital Fund LLC | Maximum

Subsidiary Sale Of Stock [Line Items]

Issuance of common stock (in shares)

1,106,580

Issuance of common stock, value | $

$ 30,000,000

Equity Purchase Agreement | Lincoln Park Capital Fund LLC | Maximum | Purchase Agreement 35.00 Closing Price

Subsidiary Sale Of Stock [Line Items]

Regular purchase amount shares

15,000

Equity Purchase Agreement | Lincoln Park Capital Fund LLC | Maximum | Purchase Agreement 50.00 Closing Price

Subsidiary Sale Of Stock [Line Items]

Regular purchase amount shares

20,000

Equity Purchase Agreement | Lincoln Park Capital Fund LLC | Maximum | Purchase Agreement 70.00 Closing Price

Subsidiary Sale Of Stock [Line Items]

Regular purchase amount shares

25,000

Equity Purchase Agreement | Common Stock | Lincoln Park Capital Fund LLC

Subsidiary Sale Of Stock [Line Items]

Issuance of common stock (in shares)

90,000

[1]

25,244

Proceeds from sale of common stock | $

$ 6,200,000

Other expense related to transaction with Lincoln Park Capital Fund | $

$ 800,000

Equity Purchase Agreement | Common Stock | Lincoln Park Capital Fund LLC | Regular Purchase Amount per Business Day | Maximum

Subsidiary Sale Of Stock [Line Items]

Issuance of common stock (in shares)

10,000

Follow On Offering

Subsidiary Sale Of Stock [Line Items]

Gross proceeds | $

$ 45,000,000

Proceeds from sale of common stock | $

$ 41,700,000

Number of warrants exercised

0

Follow On Offering | Maximum

Subsidiary Sale Of Stock [Line Items]

Warrants exercisable term

5 years

Warrant exercise percentage of ordinary shares outstanding beneficially owned

4.99%

Follow On Offering | Common Stock

Subsidiary Sale Of Stock [Line Items]

Issuance of common stock (in shares)

6,428,571

Share purchase price | $ / shares

$ 7

Follow On Offering | Warrants

Subsidiary Sale Of Stock [Line Items]

Exercise price for warrant | $ / shares

$ 8.50

Warrants issued to purchase ordinary shares

6,428,572

[1] The Company effected a reverse stock split of its outstanding shares of common stock on October 19, 2022 where every ten shares of its common stock issued and outstanding was converted into one share of common stock. Any fractional post-split shares as a result of the reverse split were rounded down to the nearest whole post-split share. Shareholders of the Company previously authorized the Board of Directors to approve a reverse stock split at the annual meeting on October 18, 2022. All share amounts and per share amounts disclosed in this Quarterly Report on Form 10-Q have been restated to reflect the reverse stock split on a retroactive basis in all periods presented.

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Stock Option Activity (Details)	3 Months Ended
	Mar. 31, 2023 $ / shares shares
Number of Shares
Balances at December 31, 2022 | shares	1,609,938
Granted | shares	9,000
Canceled | shares	(14,980)
Balances at March 31, 2023 | shares	1,603,958
Weighted-Average Exercise Price
Balances at December 31, 2022 | $ / shares	$ 27.51
Granted | $ / shares	4.39
Canceled | $ / shares	18.92
Balances at March 31, 2023 | $ / shares	$ 27.46

Stock-Based Compensation - Su_2

Stock-Based Compensation - Summary of Restricted Stock Units, Performance Stock Units and Restricted Stock Awards Activity (Details) - RSU, RSA and PSU	3 Months Ended
	Mar. 31, 2023 $ / shares shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares, Unvested at December 31, 2022 | shares	146,333
Shares, Vested | shares	(37,131)
Shares, Canceled | shares	(750)
Shares, Unvested at March 31, 2023 | shares	108,452
Weighted-Average Grant Date Fair Value, Unvested at December 31, 2022 | $ / shares	$ 27.66
Weighted-Average Grant Date Fair Value, Vested | $ / shares	28.83
Weighted-Average Grant Date Fair Value, Canceled | $ / shares	10.60
Weighted-Average Grant Date Fair Value, Unvested at March 31, 2023 | $ / shares	$ 27.37

Stock-Based Compensation - Su_3

Stock-Based Compensation - Summary of Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 2,270	$ 2,660
Research And Development Expense
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	757	1,004
General And Administrative Expense
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 1,513	$ 1,656

Net Loss per Common Share - Sch

Net Loss per Common Share - Schedule of Reconciliation of Numerators and Denominators Used In Computing Net Loss From Continuing Operations Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended
		Mar. 31, 2023	Mar. 31, 2022
Numerator:
Net loss		$ (10,865)	$ (18,915)
Denominator:
Weighted-average number of shares outstanding—basic	[1]	14,312,887	6,752,855
Weighted-average number of shares outstanding—diluted	[1]	14,312,887	6,752,855
Net loss per share, basic		$ (0.76)	$ (2.80)
Net loss per share, diluted		$ (0.76)	$ (2.80)
[1] The Company effected a reverse stock split of its outstanding shares of common stock on October 19, 2022 where every ten shares of its common stock issued and outstanding was converted into one share of common stock. Any fractional post-split shares as a result of the reverse split were rounded down to the nearest whole post-split share. Shareholders of the Company previously authorized the Board of Directors to approve a reverse stock split at the annual meeting on October 18, 2022. All share amounts and per share amounts disclosed in this Quarterly Report on Form 10-Q have been restated to reflect the reverse stock split on a retroactive basis in all periods presented.

Net Loss per Common Share - Sum

Net Loss per Common Share - Summary of Potentially Dilutive Securities Excluded from Computation of Diluted Per Share (Details) - shares	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of diluted net loss per share	8,210,257	1,202,349
Options to Purchase Common Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of diluted net loss per share	1,603,958	984,677
Outstanding Warrants to Purchase Common Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of diluted net loss per share	6,428,572
Early Exercised Common Stock Subject to Future Vesting
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of diluted net loss per share	3,336	3,336
RSUs
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of diluted net loss per share	108,452	199,835
Shares Subject to 2018 ESPP
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of diluted net loss per share	65,939	14,501

Net Loss per Common Share - Add

Net Loss per Common Share - Additional Information (Details)	3 Months Ended
	Mar. 31, 2023 shares
Maximum
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Shares contingently issued	3,390

Defined Contribution Plan - Add

Defined Contribution Plan - Additional Information (Details) - Defined Contribution Plan - USD ($) $ in Millions	1 Months Ended	3 Months Ended
	Jan. 31, 2019	Mar. 31, 2023	Mar. 31, 2022
Defined Contribution Plan Disclosure [Line Items]
Percent of employer matching contribution of employees' salary	4%
Defined Contribution Plan, Sponsor Location [Extensible Enumeration]	us-gaap:DomesticPlanMember
Matching contributions		$ 0.1	$ 0.2

Subsequent Events - Additional

Subsequent Events - Additional Information (Details) $ / shares in Units, $ in Millions	Jun. 30, 2023 Employee	May 31, 2023 Employee	May 04, 2023 USD ($) $ / shares
Forecast
Subsequent Event [Line Items]
Expected number of employees departing | Employee	3	9
Percentage of employees eliminated		29%
Subsequent Events
Subsequent Event [Line Items]
Restructuring implementation date			May 04, 2023
Subsequent Events | Operating Expenses
Subsequent Event [Line Items]
One-time employee benefits and severance charge | $			$ 0.8
Subsequent Events | Minimum | 2018 Incentive Award Plan
Subsequent Event [Line Items]
Exercise price | $ / shares			$ 6