Unity Biotechnology (UBX) 10-Q 8 Nov 22 2022 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2022	Nov. 04, 2022
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Transition Report	false
Amendment Flag	false
Document Period End Date	Sep. 30, 2022
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q3
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		14,192,305
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		Sep. 30, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents		$ 22,576	$ 32,905	[1]
Short-term marketable securities		76,364	55,170	[1]
Prepaid expenses and other current assets		3,234	1,879	[1]
Restricted cash		550	550	[1]
Total current assets		102,724	90,504	[1]
Property and equipment, net		8,202	9,942	[1]
Operating lease right-of-use assets		19,515	21,286	[1]
Long-term marketable securities		4,980	1,993	[1]
Long-term restricted cash		896	896	[1]
Other long-term assets		76	91	[1]
Total assets		136,393	124,712	[1]
Current liabilities:
Accounts payable		2,444	1,985	[1]
Accrued compensation		2,961	4,028	[1]
Accrued and other current liabilities		4,593	6,370	[1]
Deferred revenue		0	216	[1]
Derivative liability related to debt		0	963	[1]
Current portion of long-term debt		6,776	3,055	[1]
Total current liabilities		16,774	16,617	[1]
Operating lease liability, net of current portion		27,792	30,094	[1]
Long-term debt, net		13,262	18,409	[1]
Other long-term liabilities		0	23	[1]
Total liabilities		57,828	65,143	[1]
Commitments and contingencies (Note 6)
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 September 30, 2022 and December 31, 2021; 14,036,249 and 6,299,191 shares issued and outstanding as of September 30, 2022 and December 31, 2021, respectively	[2]	1	1	[1]
Additional paid-in capital		524,623	459,636	[1]
Accumulated other comprehensive loss		(275)	(44)	[1]
Accumulated deficit		(445,784)	(400,024)	[1]
Total stockholders’ equity		78,565	59,569	[1]
Total liabilities and stockholders’ equity		$ 136,393	$ 124,712	[1]
[1] The balance sheet as of December 31, 2021 (as adjusted for the Reverse Split, as defined in Note 2) 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 where every ten shares of its common stock issued and outstanding was converted into one share of 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.

Condensed Balance Sheets (Paren

Condensed Balance Sheets (Parenthetical) (Unaudited)	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2022 $ / shares shares	Sep. 30, 2022 $ / shares shares	Dec. 31, 2021 $ / shares shares
Statement Of Financial Position [Abstract]
Convertible preferred stock, par value | $ / shares	$ 0.0001	$ 0.0001	$ 0.0001
Convertible preferred stock, shares authorized	10,000,000	10,000,000	10,000,000
Convertible preferred stock, shares issued	0	0	0
Convertible preferred stock, shares outstanding	0	0	0
Common stock, par value | $ / shares	$ 0.0001	$ 0.0001	$ 0.0001
Common stock, shares authorized	300,000,000	300,000,000	300,000,000
Common stock, shares issued	14,036,249	14,036,249	6,299,191
Common stock, shares outstanding	14,036,249	14,036,249	6,299,191
Reverse stock split ratio	0.1	0.1	0.1

Condensed Statements of Operati

Condensed Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Statement Of Income And Comprehensive Income [Abstract]
Licensing revenue - related party		$ 0	$ 0	$ 236	$ 0
Operating expenses:
Research and development		8,208	9,081	28,222	28,815
General and administrative		4,922	5,747	15,669	17,952
Total operating expenses		13,130	14,828	43,891	46,767
Loss from operations		(13,130)	(14,828)	(43,655)	(46,767)
Interest income		329	20	416	82
Interest expense		(866)	(792)	(2,568)	(2,351)
Other income (expense), net		(41)	(850)	49	(996)
Net loss		(13,708)	(16,450)	(45,758)	(50,032)
Other comprehensive (loss) gain
Unrealized loss on marketable debt securities		(88)	1	(231)
Comprehensive loss		$ (13,796)	$ (16,450)	$ (45,989)	$ (50,032)
Net loss per share, basic		$ (1.36)	$ (2.97)	$ (5.77)	$ (9.13)
Net loss per share, diluted		$ (1.36)	$ (2.97)	$ (5.77)	$ (9.13)
Weighted-average number of shares used in computing net loss per share, basic	[1]	10,072,077	5,543,644	7,928,729	5,482,648
Weighted-average number of shares used in computing net loss per share, diluted	[1]	10,072,077	5,543,644	7,928,729	5,482,648
[1] The Company effected a reverse stock split of its outstanding shares of common stock where every ten shares of its common stock issued and outstanding was converted into one share of 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.

Condensed Statements of Opera_2

Condensed Statements of Operations and Comprehensive Loss (Parenthetical) (Unaudited)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Statement Of Income And Comprehensive Income [Abstract]
Reverse stock split ratio	0.1	0.1	0.1	0.1	0.1

Condensed Statements of Stockho

Condensed Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands		Total		At The Market Equity Offering Program	Follow-on Offering	Equity Purchase Agreement Lincoln Park Capital Fund LLC	Loan Agreement Hercules Capital	Common Stock		Common Stock At The Market Equity Offering Program	Common Stock Follow-on Offering	Common Stock Equity Purchase Agreement Lincoln Park Capital Fund LLC	Common Stock Loan Agreement Hercules Capital	Additional Paid-In Capital	Additional Paid-In Capital At The Market Equity Offering Program	Additional Paid-In Capital Follow-on Offering	Additional Paid-In Capital Equity Purchase Agreement Lincoln Park Capital Fund LLC	Additional Paid-In Capital Loan Agreement Hercules Capital	Related Party Promissory Notes for Purchase of Common Stock	Promissory Notes for Purchase of Common Stock	Accumulated Other Comprehensive Gain (Loss)	Accumulated Deficit
Beginning balance at Dec. 31, 2020		$ 82,880						$ 1	[1]					$ 422,383					$ (210)		$ 5	$ (339,299)
Beginning balance, (in shares) at Dec. 31, 2020	[1]							5,325,321
Issuance of common stock, net of issuance costs				$ 8,892											$ 8,892
Issuance of common stock (in shares)	[1]									122,063
Vesting of restricted stock units, (in shares)	[1]							8,822
Issuance of common stock under 2018 ESPP		1,183												1,183
Issuance of common stock upon exercise of stock options (in shares)	[1]							25,902
Repurchase of early exercised shares, (in shares)	[1]							(3,337)
Stock-based compensation		2,744												2,744
Reclass of promissory notes for purchase of common stock																			210	$ (210)
Unrealized loss on marketable debt securities		10																			10
Net loss		(15,756)																				(15,756)
Ending balance at Mar. 31, 2021		79,953						$ 1	[1]					435,202						(210)	15	(355,055)
Ending balance, (in shares) at Mar. 31, 2021	[1]							5,478,771
Beginning balance at Dec. 31, 2020		82,880						$ 1	[1]					422,383					(210)		5	(339,299)
Beginning balance, (in shares) at Dec. 31, 2020	[1]							5,325,321
Net loss		(50,032)
Ending balance at Sep. 30, 2021		57,737						$ 1	[1]					447,061							6	(389,331)
Ending balance, (in shares) at Sep. 30, 2021	[1]							5,746,988
Beginning balance at Dec. 31, 2020		82,880						$ 1	[1]					422,383					$ (210)		5	(339,299)
Beginning balance, (in shares) at Dec. 31, 2020	[1]							5,325,321
Issuance of common stock (in shares)						300,000
Ending balance at Dec. 31, 2021		$ 59,569	[2]					$ 1	[3]					459,636							(44)	(400,024)
Ending balance, (in shares) at Dec. 31, 2021		6,299,191						6,299,191	[3]
Beginning balance at Mar. 31, 2021		$ 79,953						$ 1	[1]					435,202						(210)	15	(355,055)
Beginning balance, (in shares) at Mar. 31, 2021	[1]							5,478,771
Vesting of restricted stock units, (in shares)	[1]							2,308
Issuance of common stock under 2018 ESPP		612												612
Issuance of common stock upon exercise of stock options (in shares)	[1]							23,852
Stock-based compensation		2,782												2,782
Issuance of common stock under employee stock purchase plan (“2018 ESPP”)		196												196
Issuance of common stock under employee stock purchase plan ("2018 ESPP") (in Shares)	[1]							5,494
Repayment of promissory note for purchase of common stock		210																		$ 210
Unrealized loss on marketable debt securities		(10)																			(10)
Net loss		(17,826)																				(17,826)
Ending balance at Jun. 30, 2021		65,917						$ 1	[1]					438,792							5	(372,881)
Ending balance, (in shares) at Jun. 30, 2021	[1]							5,510,425
Issuance of common stock, net of issuance costs						$ 3,726											$ 3,726
Issuance of common stock (in shares)	[1]											127,286
Vesting of restricted stock units, (in shares)	[1]							69,272
Stock-based compensation		3,086												3,086
Common stock granted to third party		1,457												1,457
Common stock granted to third party, (in shares)	[1]							40,005
Unrealized loss on marketable debt securities		1																			1
Net loss		(16,450)																				(16,450)
Ending balance at Sep. 30, 2021		57,737						$ 1	[1]					447,061							6	(389,331)
Ending balance, (in shares) at Sep. 30, 2021	[1]							5,746,988
Beginning balance at Dec. 31, 2021		$ 59,569	[2]					$ 1	[3]					459,636							(44)	(400,024)
Beginning balance, (in shares) at Dec. 31, 2021		6,299,191						6,299,191	[3]
Issuance of common stock, net of issuance costs				3,420		$ 910	$ 3,179								3,420		$ 910	$ 3,179
Issuance of common stock (in shares)	[3]									232,500		90,000	262,761
Vesting of restricted stock units, (in shares)	[3]							30,359
Stock-based compensation		$ 2,660												2,660
Unrealized loss on marketable debt securities		(132)																			(132)
Net loss		(18,915)																				(18,915)
Ending balance at Mar. 31, 2022		50,691						$ 1	[3]					469,805							(176)	(418,939)
Ending balance, (in shares) at Mar. 31, 2022	[3]							6,914,811
Beginning balance at Dec. 31, 2021		$ 59,569	[2]					$ 1	[3]					459,636							(44)	(400,024)
Beginning balance, (in shares) at Dec. 31, 2021		6,299,191						6,299,191	[3]
Issuance of common stock (in shares)						100,000
Unrealized loss on marketable debt securities		$ (231)
Net loss		(45,758)
Ending balance at Sep. 30, 2022		$ 78,565						$ 1	[3]					524,623							(275)	(445,784)
Ending balance, (in shares) at Sep. 30, 2022		14,036,249						14,036,249	[3]
Beginning balance at Mar. 31, 2022		$ 50,691						$ 1	[3]					469,805							(176)	(418,939)
Beginning balance, (in shares) at Mar. 31, 2022	[3]							6,914,811
Issuance of common stock, net of issuance costs				13											13
Vesting of restricted stock units, (in shares)	[3]							25,481
Stock-based compensation		2,250												2,250
Issuance of common stock under employee stock purchase plan (“2018 ESPP”)		125												125
Issuance of common stock under employee stock purchase plan ("2018 ESPP") (in Shares)	[3]							18,202
Unrealized loss on marketable debt securities		(11)																			(11)
Net loss		(13,137)																				(13,137)
Ending balance at Jun. 30, 2022		39,931						$ 1	[3]					472,193							(187)	(432,076)
Ending balance, (in shares) at Jun. 30, 2022	[3]							6,958,494
Issuance of common stock, net of issuance costs				$ 8,570	$ 41,650										$ 8,570	$ 41,650
Issuance of common stock (in shares)	[3]									633,464	6,428,571
Vesting of restricted stock units, (in shares)	[3]							15,720
Stock-based compensation		2,210												2,210
Unrealized loss on marketable debt securities		(88)																			(88)
Net loss		(13,708)																				(13,708)
Ending balance at Sep. 30, 2022		$ 78,565						$ 1	[3]					$ 524,623							$ (275)	$ (445,784)
Ending balance, (in shares) at Sep. 30, 2022		14,036,249						14,036,249	[3]
[1] The Company effected a reverse stock split of its outstanding shares of common stock where every ten shares of its common stock issued and outstanding was converted into one share of 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. The balance sheet as of December 31, 2021 (as adjusted for the Reverse Split, as defined in Note 2) 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 where every ten shares of its common stock issued and outstanding was converted into one share of 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.

Condensed Statements of Cash Fl

Condensed Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended				9 Months Ended		12 Months Ended
	Sep. 30, 2022	Mar. 31, 2022	Sep. 30, 2021	Mar. 31, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Operating activities
Net loss	$ (13,708)	$ (18,915)	$ (16,450)	$ (15,756)	$ (45,758)	$ (50,032)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization					1,771	2,209
Amortization of debt issuance costs					989	578
Debt extinguishment gain upon conversion to equity					(199)	0
Net accretion and amortization of premium and discounts on marketable securities					155	868
Gain on disposal of property and equipment					(247)	0
Stock-based compensation					7,120	8,612
Other expense related to transaction with Lincoln Park Capital Fund					0	825
Non-cash rent expense					(1,891)	(1,702)
Common stock issued to third parties					0	1,457
Changes in operating assets and liabilities:
Prepaid expenses and other current assets					(1,355)	(43)
Other long-term assets					15	(105)
Accounts payable					459	(785)
Accrued compensation					(1,067)	(1,957)
Accrued liabilities and other current liabilities					(632)	21
Other long-term liabilities					(23)	23
Net cash used in operating activities					(40,663)	(40,031)
Investing activities
Purchase of marketable securities					(86,567)	(57,577)
Maturities of marketable securities					62,000	88,000
Purchase of property and equipment					(59)	(188)
Sale of property and equipment					272	0
Net cash provided by (used in) investing activities					(24,354)	30,235
Financing activities
Proceeds from issuance of common stock upon exercise of stock options, net of repurchases					0	1,784
Proceeds from repayment of employee promissory notes					0	210
Proceeds from issuance of common stock under 2018 ESPP					125	196
Net cash provided by financing activities					54,688	13,983
Net decrease in cash, cash equivalents and restricted cash					(10,329)	4,187
Cash, cash equivalents and restricted cash at beginning of the period		$ 34,351		$ 19,253	34,351	19,253	$ 19,253
Cash, cash equivalents and restricted cash at end of the period	24,022		23,440		24,022	23,440	34,351
Supplemental Disclosures of Cash Flow Information:
Cash paid for interest					1,577	1,779
Supplemental Disclosures of Non-Cash Investing and Financing Activities
Issuance of common stock in payment of debt					3,179	0
Issuance of common stock warrant in connection to follow-on offering					0	0
Cash and cash equivalents	22,576		21,994		22,576	21,994	32,905	[1]
Restricted cash	1,446		1,446		1,446	1,446
Total cash, cash equivalents and restricted cash	$ 24,022		$ 23,440		24,022	23,440	$ 34,351
ATM Offering Program
Financing activities
Proceeds from issuance of common stock, net of issuance costs					12,003	8,892
Follow-on Offering
Financing activities
Proceeds from issuance of common stock, net of issuance costs					41,650	0
Equity Purchase Agreement | Lincoln Park Capital Fund LLC
Financing activities
Proceeds from issuance of common stock, net of issuance costs					$ 910	$ 2,901
[1] The balance sheet as of December 31, 2021 (as adjusted for the Reverse Split, as defined in Note 2) is derived from the audited financial statements as of that date.

Organization

Organization	9 Months Ended
	Sep. 30, 2022
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 Company’s condensed financial statements have been prepared on a going concern basis, which contemplates the continuity of operations, realization of assets and the satisfaction of liabilities and commitments in the ordinary 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 $ 445.8 million and $ 400.0 million as of September 30, 2022 and December 31, 2021, respectively. The Company had net losses of $ 13.7 million and $ 16.5 million for the three months ended September 30, 2022 and 2021, respectively, net losses of $ 45.8 million and $ 50.0 million for the nine months ended September 30, 2022 and 2021, respectively, and net cash used in operating activities of $ 40.7 million and $ 40.0 million for the nine months ended September 30, 2022 and 2021, 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 7), 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 $ 103.9 million as of September 30, 2022. As of the date of issuance of these Condensed Financial Statements, the Company expects that its existing cash, cash equivalents and marketable securities will be sufficient to fund its current business plan including related operating expenses and capital expenditure requirements into the first quarter of 2024. The Company expects operating losses to continue for the foreseeable future and will need to raise additional capital to finance its operations. If the Company is unable to raise additional capital during the next quarter, then the above-mentioned conditions will raise substantial doubt regarding its ability to continue as a going concern. If sufficient funds on acceptable terms are not available when needed, the Company could be 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	9 Months Ended
	Sep. 30, 2022
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, 2021 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. Warrants The Company determines the accounting classification of warrants that are issued, as either liability or equity, by first assessing whether the warrants meet liability classification in accordance with ASC 480-10, Accounting for Certain Financial Instruments with Characteristics of Both Liabilities and Equity, and then in accordance with ASC 815-40, Accounting for Derivative Financial Instruments Indexed to, and Potentially Settled in, a Company’s Own Stock. Under ASC 480-10, warrants are considered liability classified if the warrants are mandatorily redeemable, obligate the issuer to settle the warrants or the underlying shares by paying cash or other assets, or must or may require settlement by issuing variable number of shares. If warrants do not meet liability classification under ASC 480-10, the Company assesses the requirements under ASC 815-40, which states that contracts that require or may require the issuer to settle the contract for cash are liabilities recorded at fair value, irrespective of the likelihood of the transaction occurring that triggers the net cash settlement feature. If the warrants do not require liability classification under ASC 815-40, in order to conclude equity classification, the Company assesses whether the warrants are indexed to its common stock and whether the warrants are classified as equity under ASC 815-40 or other applicable principles of GAAP. After all relevant assessments are made, the Company concludes whether the warrants are classified as liability or equity. Liability classified warrants are required to be accounted for at fair value both on the date of issuance and on subsequent accounting period ending dates, with all changes in fair value after the issuance date recorded in the statements of operations as a gain or loss. Equity classified warrants are accounted for at fair value on the issuance date with no changes in fair value recognized after the issuance date. Unaudited Condensed Financial Statements The accompanying financial information for the three and nine months ended September 30, 2022 and 2021 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 September 30, 2022 and its results of operations for the three and nine months ended September 30, 2022 and 2021 and cash flows for the nine months ended September 30, 2022 and 2021. 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, contingent consideration liability, the fair value of right-of-use assets and lease liabilities, derivative liabilities related to debt 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. Restructuring The Company recognizes restructuring charges related to reorganization plans that have been committed to by management and when liabilities have been incurred. In connection with these activities, the Company records restructuring charges at fair value for a) contractual employee termination benefits when obligations are associated to services already rendered, rights to such benefits have vested, and payment of benefits is probable and can be reasonably estimated, and b) one-time employee termination benefits when management has committed to a plan of termination, the plan identifies the employees and their expected termination dates, the details of termination benefits are complete, it is unlikely changes to the plan will be made or the plan will be withdrawn and communication to such employees has occurred. One-time employee termination benefits are recognized in their entirety when communication has occurred, and future services are not required. Contract termination costs to be incurred over the remaining contract term without economic benefit are recorded in their entirety when the contract is canceled. The recognition of restructuring charges requires the Company to make certain judgments and estimates regarding the nature, timing and amount of costs associated with the planned reorganization plan. At the end of each reporting period, the Company evaluates the remaining accrued restructuring balances to ensure that no excess accruals are retained, and the utilization of the provisions are for their intended purpose in accordance with developed restructuring plans. Recently Issued Accounting Pronouncements Not Yet Adopted In October 2020, the FASB issued ASU 2020-10, Codification Improvements . The ASU contains improvements to the Codification by ensuring that all guidance that requires or provides an option for an entity to provide information in the notes to financial statements is codified in the disclosure section of the Codification. The ASU also improves various topics in the Codification so that entities can apply guidance more consistently on codifications that are varied in nature where the original guidance may have been unclear. The amendments in ASU 2020-10 are effective for the Company for fiscal years beginning after December 15, 2021, and interim periods within fiscal years beginning after December 15, 2022. Early adoption is permitted. The Company does not expect the adoption of ASU 2020-10 to have a material impact on its financial statements and related disclosures. In August 2020, the FASB issued ASU No. 2020-06, Debt—Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging—Contracts in Entity’s Own Equity . ASU 2020-06 eliminates the beneficial conversion and cash conversion accounting models for convertible instruments. It also amends the accounting for certain contracts in an entity’s own equity that are currently accounted for as derivatives because of specific settlement provisions. In addition, ASU 2020-06 modifies how particular convertible instruments and certain contracts that may be settled in cash or shares impact the diluted EPS computation. The amendments in ASU 2020-06 are effective for smaller reporting companies as defined by the SEC for fiscal years beginning after December 15, 2023, including interim periods within those fiscal years. Early adoption is permitted, but no earlier than fiscal years beginning after December 15, 2020. The Company is currently evaluating the impact of ASU 2020-06 on its financial statements. 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. The Company is currently evaluating the effects of this ASU on its financial statements and related disclosures and does not expect there to be a material impact.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2022
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): September 30, 2022 Total Level 1 Level 2 Level 3 Assets: Cash equivalents: Money market funds $ 5,934 $ 5,934 $ — $ — U.S. government debt securities 9,949 — 9,949 — Total cash equivalents 15,883 5,934 9,949 — Short-term marketable securities: U.S. treasuries 40,002 — 40,002 — U.S. government debt securities 36,362 — 36,362 — Total short-term marketable securities 76,364 — 76,364 — Long-term marketable securities: U.S. government debt securities 4,980 — 4,980 Total long-term marketable securities 4,980 — 4,980 — Total assets subject to fair value measurements $ 97,227 $ 5,934 $ 91,293 $ — December 31, 2021 Total Level 1 Level 2 Level 3 Assets: Cash equivalents: Money market funds $ 21,421 $ 21,421 $ — $ — Total cash equivalents 21,421 21,421 — — Short-term marketable securities: U.S. treasuries 52,146 — 52,146 — U.S. government debt securities 3,024 — 3,024 — Total short-term marketable securities 55,170 — 55,170 — Long-term marketable securities: U.S. treasuries 1,993 — 1,993 — Total long-term marketable securities 1,993 — 1,993 — Total assets subject to fair value measurements $ 78,584 $ 21,421 $ 57,163 $ — The Company estimates the fair value of its money market funds, 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. 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. In December 2021, the Company recorded a derivative liability relating to an amendment to its loan and security agreement. It comprised of a redemption conversion feature which met the definition of a derivative instrument, which terms are included in the amended loan and security agreement. See Note 7, “Term Loan Facility”. The Company classified this instrument as a liability on the balance sheet because the feature was not clearly and closely related to its host instrument and met the definition of a derivative. The derivative liability was initially recorded at fair value upon issuance of the loan amendment and is being subsequently remeasured to fair value at each reporting date. Changes in the fair value of the derivative liability are recognized as a component of other income (expense), net in the statements of operations. The following table provides a reconciliation of the derivative liability related to debt measured at fair value on a recurring basis using significant unobservable inputs (Level 3) (in thousands): Derivative Liability related to (1) Balance at December 31, 2021 $ 963 Conversion ( 963 ) Balance at September 30, 2022 $ — Transfers into Level 3 related to the call option with Hercules Capital, Inc., where the lender can convert principal debt into common stock. Transfers out of Level 3 during the period related to the conversions calls of this option made by Hercules Capital, Inc.

Marketable Securities

Marketable Securities	9 Months Ended
	Sep. 30, 2022
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 September 30, 2022 (in thousands): Amortized Unrealized Unrealized Fair Cash equivalents: Money market funds $ 5,934 $ — $ — $ 5,934 U.S. government debt securities 9,950 — ( 1 ) 9,949 Total cash equivalents 15,884 — ( 1 ) 15,883 Short-term marketable securities: U.S. government debt securities 36,475 4 ( 117 ) 36,362 U.S. treasuries 40,144 — ( 142 ) 40,002 Total short-term marketable securities 76,619 4 ( 259 ) 76,364 Long-term marketable securities: U.S. government debt securities 5,000 ( 20 ) 4,980 Total long-term marketable securities 5,000 — ( 20 ) 4,980 Total $ 97,503 $ 4 $ ( 280 ) $ 97,227 Marketable securities, which are classified as available-for-sale, consisted of the following as of December 31, 2021 (in thousands): Amortized Unrealized Unrealized Fair Cash equivalents: Money market funds $ 21,421 $ — $ — $ 21,421 Total cash equivalents 21,421 — — 21,421 Short-term marketable securities: U.S. government debt securities 3,026 — ( 2 ) 3,024 U.S. treasuries 52,186 — ( 40 ) 52,146 Total short-term marketable securities 55,212 — ( 42 ) 55,170 Long-term marketable securities U.S. treasuries 1,995 — ( 2 ) 1,993 Total long-term marketable securities 1,995 — ( 2 ) 1,993 Total $ 78,628 $ — $ ( 44 ) $ 78,584 At September 30, 2022, the remaining contractual maturities of available-for-sale securities were less than two years . There have been no significant realized gains or losses on available-for-sale securities for the periods presented. Available-for-sale debt securities that were in a continuous loss position but were not deemed to be other than temporarily impaired were immaterial at both September 30, 2022 and December 31, 2021. The Company does not intend to and believes it is not more likely than not that it will be required to sell these debt securities before their maturities. 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	9 Months Ended
	Sep. 30, 2022
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 September 30, 2022 and December 31, 2021. 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. For the three and nine months ended September 30, 2022, the Company recognized zero and $ 0.2 million, respectively, in license revenue related to the Jocasta Agreement. No license revenue was recognized for the three and nine months ended September 30, 2021 related to the Jocasta Agreement. The deferred revenue balance was zero and $ 0.2 million as of September 30, 2022 and December 31, 2021, respectively. 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 using α-Klotho, 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. In June 2019, as part of this license agreement, the Company issued 12,000 shares of its common stock to UCSF. In addition, 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 September 30, 2022. The upfront issuance of 12,000 shares of the Company’s common stock was valued at $ 1.0 million and recorded as additional paid-in capital upon issuance in June 2019. 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. See above, “License Agreement with Jocasta Neuroscience, Inc.” for additional information on the Jocasta Agreement. 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. There was no contingent consideration liability considered to be a derivative associated with the potential issuance of common stock related to these license agreements at September 30, 2022 and December 31, 2021. 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, collectively termed the “Commercial Agreements”, with Ascentage Pharma: (a) a compound library and option agreement executed in February 2016 granting the Company the right to identify and take licenses to research, develop, and seek and obtain marketing approval for library compounds for the treatment of indications outside of oncology (the “Library Agreement”), 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 (the “APG1252 License Agreement”), and (c) a second license agreement executed in January 2019 granting the Company rights to UBX0601, the active parent molecule of our lead drug candidate UBX1325 (the “Original Bcl Agreement”). On July 30, 2020, the Company notified Ascentage Pharma of its termination of the APG1252 License Agreement due to the Company’s decision to prioritize the progression of UBX1325. 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. As of September 30, 2022, pursuant to these agreements, the Company had issued 126,975 shares of common stock to Ascentage Pharma and 29,194 shares of common stock to the academic institution from whom Ascentage Pharma had previously licensed the technology. In May 2021, the Company initiated a Phase 2 proof-of-concept study of UBX1325 in patients with diabetic macular edema. As a result of the first patient dosed in the Phase 2 proof-of-concept UBX1325 study in June 2021, the Company triggered a milestone payment of $ 2.0 million for Ascentage Pharma, which the Company elected to settle in shares of the Company’s common stock. At the instruction of Ascentage Pharma, the Company issued 29,477 shares of its common stock to Ascentage Pharma as of August 2021 with a fair market value of $ 1.1 million net of withholding taxes, and 10,527 shares of its common stock to the academic institution with a fair market value of $ 0.4 million at settlement date. The milestone payment was recognized as research and development expense in the statement of operations and comprehensive loss during the year ended December 31, 2021. The Company had previously issued 36,166 shares of its common stock with a value of $ 2.3 million to Ascentage Pharma as of December 31, 2020. The Commercial Agreements included contingent consideration in the form of additional issuances of shares of the Company’s common stock based on the achievement of the specified milestones. Upon the July 2020 termination of the license to APG1252, the Company determined that the contingency no longer applied and adjusted the fair value of the contingent consideration liability to zero . To date, no royalties were due from the sales of licensed products.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2022
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	6. 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 continues through 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 September 30, Nine Months Ended September 30, 2022 2021 2022 2021 Operating lease cost $ 1,088 $ 1,087 $ 3,239 $ 3,274 Variable lease cost 407 393 1,114 1,246 Sublease income ( 1,391 ) ( 986 ) ( 3,405 ) ( 1,521 ) Total lease cost $ 104 $ 494 $ 948 $ 2,999 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): Nine Months Ended September 30, 2022 2021 Cash paid for amounts included in the measurement of lease liabilities Operating cash flows from operating leases $ 5,109 $ 4,978 Weighted-average remaining lease term (years) Operating leases 7.3 8.2 Weighted-average discount rate (percentage) Operating leases 6.0 % 5.9 % The following table summarizes the maturities of lease liabilities as of September 30, 2022 (in thousands): Amount 2022 (remaining 3 months) $ 1,174 2023 4,810 2024 4,964 2025 5,123 2026 5,287 Thereafter 16,892 Total future minimum lease payments 38,250 Less: Amount representing interest ( 7,441 ) Present value of future minimum lease payments 30,809 Less: Current portion of operating lease liability ( 3,017 ) Noncurrent portion of operating lease liability $ 27,792 In February 2020, the Company completed its move into the new office and laboratory space in South San Francisco, exited its previous offices and laboratory space in Brisbane, California, and began to actively market this space for sublease. Concurrent with this move and in consideration of real estate market conditions, in particular due to the COVID-19 pandemic in March 2020, the Company identified indicators of impairment in the related asset group, which included the leased ROU asset and related leasehold improvements associated with the lease. The Company subsequently evaluated and compared the net book value of the asset group to the estimated undiscounted future cash flows over the remaining term of the lease and concluded that an impairment had occurred. The discounted estimated future cash flows included estimates of sublease rentals through the end of the lease term, which ends on October 31, 2022, utilizing a discount rate of 3.5 % based on the Company’s estimated incremental borrowing rate at that time. The estimated discounted cash flows were compared to the net book value of the ROU asset and leasehold improvements resulting in an impairment loss of $ 2.6 million during the year ended December 31, 2020, which was included in operating expense in the statements of operations and comprehensive loss. No impairment loss was recorded during the three and nine months ended September 30, 2022. In February 2021, the Company entered into an agreement to sublease the first floor of the Brisbane, California facility, consisting of approximately 27,000 square feet, to Zymergen, Inc., through August 31, 2022 . The base sublease rent rate is $ 3.53 per rental square foot per month and will increase by 3 % on March 1, 2022 through expiration of the agreement. Additionally, the subtenant is required to pay approximately 41 % of operating expenses and property management fees that the Company is required to pay under the lease for the Brisbane, California facility. In May 2021, the Company entered into an agreement to sublease the second floor of the Brisbane, California facility, consisting of approximately 11,500 square feet, to CareDx, Inc., through September 30, 2022 . The base sublease rent rate is $ 1.00 per rental square foot per month through expiration of the agreement. Additionally, the subtenant is required to pay approximately 30 % of operating expenses and property management fees that the Company is required to pay under the lease for the Brisbane, California facility. The Company incurred initial direct costs of $ 0.1 million in sublease commissions related to entering into the agreements to sublease the Brisbane, 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. Sublease income was $ 0.4 million and $ 0.5 million for the three months ended September 30, 2022 and 2021, respectively, and $ 1.3 million and $ 1.0 million for the nine months ended September 30, 2022 and 2021, respectively. 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. No impairment loss was recorded during the three and nine months ended September 30, 2022. Sublease income was $ 1.0 million and $ 0.5 million for the three months ended September 30, 2022 and 2021, respectively, and $ 2.1 million and $ 0.5 million for the nine months ended September 30, 2022 and 2021, respectively. In May 2022, the Company entered into an agreement to sublease a portion of the second floor of the South San Francisco 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 facility. No impairment loss was recorded during the three and nine months ended September 30, 2022. 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	9 Months Ended
	Sep. 30, 2022
Debt Disclosure [Abstract]
Term Loan Facility	7. 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 September 30, 2022 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. gave notice 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. As a result, the Company is able to extend its interest only period and expects to make interest only payments through March 1, 2023. The Company expects to then repay the principal balance and interest in equal monthly installments through August 1, 2024 . The interest only period may extend an additional 3 months to June 1, 2023 should the Company meet additional specific milestones related to its clinical trials. 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 July 28, 2022, the prime rate was raised to 5.50 % and on September 22, 2022, the prime rate was raised again to 6.25 %. On September 30, 2022, the interest rate on the term loan was 12.35 %. Interest expense is calculated using the effective interest method and is inclusive of non-cash amortization of capitalized loan issuance costs. At September 30, 2022, the effective interest rate was 18.90 %. 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 (including a liquidity covenant beginning July 1, 2021, requiring the Company to maintain at least $ 15.0 million in unrestricted cash), 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. 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 substantial doubt regarding the Company’s ability to continue as a going concern does not constitute a material adverse event under the terms of 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 September 30, 2022 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 September 30, 2022, the carrying value of the term loan consists of $ 20.0 million principal outstanding less the debt discount and issuance costs of approximately $ 1.5 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 $ 0.9 million and $ 0.8 million for the three months ended September 30, 2022 and 2021, respectively, and $ 2.6 million and $ 2.4 million for the nine months ended September 30, 2022 and 2021, respectively. Future principal payments for the long-term debt as of September 30, 2022 are as follows (in thousands): Amount 2022 (for the remaining 3 months) $ — 2023 10,642 2024 9,358 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 ( 1,525 ) Present value of remaining debt payments 20,038 Current portion of long-term debt ( 6,776 ) Long-term debt, net $ 13,262

Related Party Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 2022
Related Party Transactions [Abstract]
Related-Party Transactions	8. Related Party Transactions Licensing Revenue – Related Party In December 2021, the Company entered into a license agreement with Jocasta Neuroscience, Inc. A member of the Board of Directors of the Company is also an affiliate of Jocasta Neuroscience, Inc. The agreement provides for an upfront fee of $ 5.0 million and the opportunity for future research and development services to be provided. The Company recognized $ 4.8 million of licensing revenue for the year ended December 31, 2021. Licensing revenue of zero and $ 0.2 million was recognized for the three and nine months ended September 30, 2022, respectively. No licensing revenue was recognized for the three and nine months ended September 30, 2021.

Equity Financing

Equity Financing	9 Months Ended
	Sep. 30, 2022
Equity [Abstract]
Equity Financing	9. Equity Financing Follow-On Offering On August 22, 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 September 30, 2022. 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 3.0 % of the gross proceeds of any shares of common stock sold under the March 2022 Sales Agreement. During the three and nine month period ended September 30, 2022, there were 633,464 shares of the Company's common stock sold pursuant to the March 2022 Sales Agreement and the Company received total net proceeds of approximately $ 8.6 million, after deducting commissions and other offering expenses of $ 0.3 million. 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, $ 16.1 million of shares of common stock remained available for sale under the March 2022 Sales Agreement, as amended, as of September 30, 2022. Equity Purchase Agreement On September 29, 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. As of December 31, 2021, the Company had initiated the purchase of an additional 0.3 million shares of the Company’s common stock amounting to $ 5.3 million in gross proceeds. During the nine months ended September 30, 2022, the Company initiated purchases of an additional 0.1 million shares of the Company’s common stock amounting to $ 0.9 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: to 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.

Corporate Restructuring

Corporate Restructuring	9 Months Ended
	Sep. 30, 2022
Restructuring And Related Activities [Abstract]
Corporate Restructuring	10 . Corporate Restructuring In February 2022 , the Company implemented a corporate restructuring to align its resources to focus on its UBX1325 program while further extending operating capital. The restructuring resulted in an elimination of 29 positions, or approximately 50 % of the Company’s workforce, in the first nine months of 2022. The Company incurred a one-time employee benefits and severance charge of approximately $ 1.9 million in operating expenses which was primarily recorded in the first nine months of 2022. Restructuring charges incurred under this plan primarily consisted of employee termination benefits. Employee termination benefits include $ 1.6 million of severance costs, $ 0.2 million of employee-related benefits, $ 0.1 million of payroll taxes and supplemental one-time termination payments. Charges and other costs related to the workforce reduction and structure realignment, and non-cash share-based compensation credits related to the forfeiture of stock options for $ 1.2 million are included in operating expenses in the condensed statements of operations and comprehensive loss. Of the total charge, $ 1.4 million was recorded to research and development expenses and $ 0.5 million was recorded to general and administrative expenses during the nine months ended September 30, 2022. The Company may also incur additional costs not currently contemplated due to events that may occur as a result of, or that are associated with, the restructuring. The Company may also incur additional costs not currently contemplated due to events that may occur as a result of, or that are associated with, the restructuring.

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 30, 2022
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-Based Compensation	11 . 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 nine months ended September 30, 2022 is as follows: Number of Weighted- Balances at December 31, 2021 866,695 $ 60.47 Granted 215,314 $ 10.12 Canceled ( 168,986 ) $ 65.42 Balances at September 30, 2022 913,023 $ 47.68 A summary of the Company’s restricted stock units (“RSUs”), performance stock units (“PSUs”), and restricted stock awards (“RSAs”) activity for the nine months ended September 30, 2022 is as follows: Number of Weighted- Unvested at December 31, 2021 199,094 $ 39.22 Granted 46,332 $ 10.60 Vested ( 71,560 ) $ 40.42 Canceled ( 22,065 ) $ 35.98 Unvested at September 30, 2022 151,801 $ 30.39 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. In March 2020, the board of directors granted the Company’s newly hired Chief Executive Officer stock-based awards covering an aggregate of 0.1 million shares of common stock, including options to purchase an aggregate of 80,000 shares of common stock, 12,000 RSUs, 15,000 PSUs, and 3,000 shares of common stock. The stock-based awards were granted pursuant to the 2020 Employment Inducement Incentive Plan, which was approved by the board of directors in March 2020 to provide for grants to newly hired employees as a material inducement for them to commence employment with the Company. The 3,000 shares of common stock were fully vested on the date of grant and thus, the related compensation expense of $ 0.2 million was recognized on the grant date. The stock options and RSUs will vest subject to continued service through the applicable vesting date. The PSUs were originally scheduled to vest as to 5,000 PSUs upon the attainment of (a) a volume-weighted average per share closing trading price of the Company’s common stock of at least $ 368.75 over a trailing 30 -day period or (b) a change in control transaction in which the price per share to the holders of the Company’s common stock is at least $ 368.75 and as to 10,000 PSUs (x) at such time as the Company’s market capitalization reaches at least $ 2.5 billion, as measured based on the volume weighted-average closing trading price over a trailing 30 day period or (y) a change in control transaction in which the consideration paid to the Company’s stockholders is equal to at least $ 2.5 billion, as determined by the Company’s board of directors. In January 2021, the board of directors modified the PSUs to vest as to 5,000 PSUs upon the attainment of (a) a volume-weighted average per share closing trading price of the Company’s common stock of at least $ 180.00 over a trailing 30 -day period or (b) a change in control transaction in which the price per share to the holders of the Company’s common stock is at least $ 180.00 and as to 10,000 PSUs upon the attainment of (x) a volume-weighted average per share closing trading price of the Company’s common stock of at least $ 360.00 over a trailing 30 -day period or (y) a change in control transaction in which the price per share to the holders of the Company’s common stock is at least $ 360.00 , as determined by the Company’s board of directors . For the PSU awards, the Company used the Monte-Carlo option pricing model to determine the fair value of awards at the date of grant. The Monte-Carlo option pricing model uses similar input assumptions as the Black-Scholes model; however, it further incorporates into the fair-value determination the possibility that the market condition may not be satisfied. Compensation costs related to awards with a market-based condition are recognized regardless of whether the market condition is ultimately satisfied. Compensation cost is not reversed if the achievement of the market condition does not occur. The total grant date fair value of the PSU awards was determined to be $ 0.7 million and will be recognized as compensation expense over the weighted-average derived service period of approximately 4.3 years. The incremental fair value of the PSUs on the modification date of $ 31,000 are added to the unamortized value of the original grant of $ 569,000 and will be amortized to expense over the new implied service periods of 1.63 years to 2.79 years. In February 2022, the Company’s board of directors approved the granting of retention awards to critical and important Company personnel. The awards consisted of 189,333 stock options and 46,332 restricted stock units with a grant date total fair value of $ 2.0 million and $ 0.5 million, respectively. Performance and Market Contingent Stock Options In January 2021, the board of directors modified 1,747 performance and market contingent stock options with vesting conditions that required the combination of a liquidity event, change of control or IPO with a market condition at prescribed levels. The modification removed the performance condition and lowered the market conditions to a volume-weighted average per share closing trading price of the Company’s common stock of at least $ 180.00 over a trailing 30 -day period for one tranche and at least $ 360.00 over a trailing 30 -day period for the second tranche. The fair value of the options on the modification date of $ 81,000 will be amortized to expense over the implied service periods of 1.46 years to 2.52 years. In June 2021, the board of directors modified 3,337 performance and market contingent stock options with vesting conditions that required the combination of a liquidity event, change of control or IPO with a market condition at prescribed levels. The modification removed the performance condition and adjusted the market conditions to a date on which the Company attains a valuation of at least one billion dollars measured by the volume-weighted average per share closing trading price of the Company’s common stock over a trailing 30 -day period. The fair value of the options on the modification date of $ 102,000 will be amortized to expense over the implied service periods of 1.85 years. As of September 30, 2022, there were 3,337 market contingent stock option awards outstanding with a total fair value of $ 0.1 million. 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 September 30, Nine Months Ended September 30, 2022 2021 2022 2021 Research and development $ 799 $ 1,329 $ 2,723 $ 3,518 General and administrative 1,411 1,757 4,397 5,094 Total $ 2,210 $ 3,086 $ 7,120 $ 8,612 There was no stock-based compensation expense related to awards accounted for as liability awards for the three and nine months ended September 30, 2022 and 2021.

Net Loss per Common Share

Net Loss per Common Share	9 Months Ended
	Sep. 30, 2022
Earnings Per Share [Abstract]
Net Loss per Common Share	12. 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 September 30, Nine Months Ended September 30, 2022 2021 2022 2021 Numerator: Net loss $ ( 13,708 ) $ ( 16,450 ) $ ( 45,758 ) $ ( 50,032 ) Denominator: Weighted-average number of shares 10,072,077 5,543,644 7,928,729 5,482,648 Net loss per share—basic and diluted $ ( 1.36 ) $ ( 2.97 ) $ ( 5.77 ) $ ( 9.13 ) 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: September 30, 2022 2021 Options to purchase common stock 913,023 864,780 Warrants to purchase common stock 6,428,572 — Early exercised common stock subject to future vesting 3,337 3,337 RSUs 151,801 223,532 Shares subject to 2018 ESPP 9,255 8,077 Total 7,505,988 1,099,726 Up to 5,590 shares may be contingently issued, if certain performance conditions are met under the Company’s in-licensing agreements. See Note 5, “License Revenue and Agreements,” to our condensed financial statements for additional information.

Defined Contribution Plan

Defined Contribution Plan	9 Months Ended
	Sep. 30, 2022
Compensation And Retirement Disclosure [Abstract]
Defined Contribution Plan	13. 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 September 30, 2022 and 2021, the Company recorded matching contributions of $ 0.1 million and $ 0.1 million, respectively, and $ 0.4 million and $ 0.4 million for the nine months ended September 30, 2022 and 2021, respectively.

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2022
Subsequent Events [Abstract]
Subsequent Events	14. Subsequent Events 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. 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. 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 3.0 % of the gross proceeds of any shares of common stock sold under the October 2022 Sales Agreement. From October 1, 2022 through November 8, 2022, the Company has sold and issued 153,082 shares of common stock through the March 2022 ATM Offering Program and received total net proceeds of approximately $ 0.5 million, after deducting commissions and other offering expenses of $ 0.1 million.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2022
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, 2021 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.
Warrants	Warrants The Company determines the accounting classification of warrants that are issued, as either liability or equity, by first assessing whether the warrants meet liability classification in accordance with ASC 480-10, Accounting for Certain Financial Instruments with Characteristics of Both Liabilities and Equity, and then in accordance with ASC 815-40, Accounting for Derivative Financial Instruments Indexed to, and Potentially Settled in, a Company’s Own Stock. Under ASC 480-10, warrants are considered liability classified if the warrants are mandatorily redeemable, obligate the issuer to settle the warrants or the underlying shares by paying cash or other assets, or must or may require settlement by issuing variable number of shares. If warrants do not meet liability classification under ASC 480-10, the Company assesses the requirements under ASC 815-40, which states that contracts that require or may require the issuer to settle the contract for cash are liabilities recorded at fair value, irrespective of the likelihood of the transaction occurring that triggers the net cash settlement feature. If the warrants do not require liability classification under ASC 815-40, in order to conclude equity classification, the Company assesses whether the warrants are indexed to its common stock and whether the warrants are classified as equity under ASC 815-40 or other applicable principles of GAAP. After all relevant assessments are made, the Company concludes whether the warrants are classified as liability or equity. Liability classified warrants are required to be accounted for at fair value both on the date of issuance and on subsequent accounting period ending dates, with all changes in fair value after the issuance date recorded in the statements of operations as a gain or loss. Equity classified warrants are accounted for at fair value on the issuance date with no changes in fair value recognized after the issuance date.
Unaudited Condensed Financial Statements	Unaudited Condensed Financial Statements The accompanying financial information for the three and nine months ended September 30, 2022 and 2021 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 September 30, 2022 and its results of operations for the three and nine months ended September 30, 2022 and 2021 and cash flows for the nine months ended September 30, 2022 and 2021. 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, contingent consideration liability, the fair value of right-of-use assets and lease liabilities, derivative liabilities related to debt 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.
Restructurings	Restructuring The Company recognizes restructuring charges related to reorganization plans that have been committed to by management and when liabilities have been incurred. In connection with these activities, the Company records restructuring charges at fair value for a) contractual employee termination benefits when obligations are associated to services already rendered, rights to such benefits have vested, and payment of benefits is probable and can be reasonably estimated, and b) one-time employee termination benefits when management has committed to a plan of termination, the plan identifies the employees and their expected termination dates, the details of termination benefits are complete, it is unlikely changes to the plan will be made or the plan will be withdrawn and communication to such employees has occurred. One-time employee termination benefits are recognized in their entirety when communication has occurred, and future services are not required. Contract termination costs to be incurred over the remaining contract term without economic benefit are recorded in their entirety when the contract is canceled. The recognition of restructuring charges requires the Company to make certain judgments and estimates regarding the nature, timing and amount of costs associated with the planned reorganization plan. At the end of each reporting period, the Company evaluates the remaining accrued restructuring balances to ensure that no excess accruals are retained, and the utilization of the provisions are for their intended purpose in accordance with developed restructuring plans.
Recently Issued Accounting Pronouncements Not Yet Adopted	Recently Issued Accounting Pronouncements Not Yet Adopted In October 2020, the FASB issued ASU 2020-10, Codification Improvements . The ASU contains improvements to the Codification by ensuring that all guidance that requires or provides an option for an entity to provide information in the notes to financial statements is codified in the disclosure section of the Codification. The ASU also improves various topics in the Codification so that entities can apply guidance more consistently on codifications that are varied in nature where the original guidance may have been unclear. The amendments in ASU 2020-10 are effective for the Company for fiscal years beginning after December 15, 2021, and interim periods within fiscal years beginning after December 15, 2022. Early adoption is permitted. The Company does not expect the adoption of ASU 2020-10 to have a material impact on its financial statements and related disclosures. In August 2020, the FASB issued ASU No. 2020-06, Debt—Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging—Contracts in Entity’s Own Equity . ASU 2020-06 eliminates the beneficial conversion and cash conversion accounting models for convertible instruments. It also amends the accounting for certain contracts in an entity’s own equity that are currently accounted for as derivatives because of specific settlement provisions. In addition, ASU 2020-06 modifies how particular convertible instruments and certain contracts that may be settled in cash or shares impact the diluted EPS computation. The amendments in ASU 2020-06 are effective for smaller reporting companies as defined by the SEC for fiscal years beginning after December 15, 2023, including interim periods within those fiscal years. Early adoption is permitted, but no earlier than fiscal years beginning after December 15, 2020. The Company is currently evaluating the impact of ASU 2020-06 on its financial statements. 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. The Company is currently evaluating the effects of this ASU on its financial statements and related disclosures and does not expect there to be a material impact.
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, 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. 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)	9 Months Ended
	Sep. 30, 2022
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): September 30, 2022 Total Level 1 Level 2 Level 3 Assets: Cash equivalents: Money market funds $ 5,934 $ 5,934 $ — $ — U.S. government debt securities 9,949 — 9,949 — Total cash equivalents 15,883 5,934 9,949 — Short-term marketable securities: U.S. treasuries 40,002 — 40,002 — U.S. government debt securities 36,362 — 36,362 — Total short-term marketable securities 76,364 — 76,364 — Long-term marketable securities: U.S. government debt securities 4,980 — 4,980 Total long-term marketable securities 4,980 — 4,980 — Total assets subject to fair value measurements $ 97,227 $ 5,934 $ 91,293 $ — December 31, 2021 Total Level 1 Level 2 Level 3 Assets: Cash equivalents: Money market funds $ 21,421 $ 21,421 $ — $ — Total cash equivalents 21,421 21,421 — — Short-term marketable securities: U.S. treasuries 52,146 — 52,146 — U.S. government debt securities 3,024 — 3,024 — Total short-term marketable securities 55,170 — 55,170 — Long-term marketable securities: U.S. treasuries 1,993 — 1,993 — Total long-term marketable securities 1,993 — 1,993 — Total assets subject to fair value measurements $ 78,584 $ 21,421 $ 57,163 $ —
Summary of Reconciliation of Derivative Liability Related to Debt Measured at Fair Value on a Recurring Basis Using Significant Unobservable Inputs	The following table provides a reconciliation of the derivative liability related to debt measured at fair value on a recurring basis using significant unobservable inputs (Level 3) (in thousands): Derivative Liability related to (1) Balance at December 31, 2021 $ 963 Conversion ( 963 ) Balance at September 30, 2022 $ — Transfers into Level 3 related to the call option with Hercules Capital, Inc., where the lender can convert principal debt into common stock. Transfers out of Level 3 during the period related to the conversions calls of this option made by Hercules Capital, Inc.

Marketable Securities (Tables)

Marketable Securities (Tables)	9 Months Ended
	Sep. 30, 2022
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 September 30, 2022 (in thousands): Amortized Unrealized Unrealized Fair Cash equivalents: Money market funds $ 5,934 $ — $ — $ 5,934 U.S. government debt securities 9,950 — ( 1 ) 9,949 Total cash equivalents 15,884 — ( 1 ) 15,883 Short-term marketable securities: U.S. government debt securities 36,475 4 ( 117 ) 36,362 U.S. treasuries 40,144 — ( 142 ) 40,002 Total short-term marketable securities 76,619 4 ( 259 ) 76,364 Long-term marketable securities: U.S. government debt securities 5,000 ( 20 ) 4,980 Total long-term marketable securities 5,000 — ( 20 ) 4,980 Total $ 97,503 $ 4 $ ( 280 ) $ 97,227 Marketable securities, which are classified as available-for-sale, consisted of the following as of December 31, 2021 (in thousands): Amortized Unrealized Unrealized Fair Cash equivalents: Money market funds $ 21,421 $ — $ — $ 21,421 Total cash equivalents 21,421 — — 21,421 Short-term marketable securities: U.S. government debt securities 3,026 — ( 2 ) 3,024 U.S. treasuries 52,186 — ( 40 ) 52,146 Total short-term marketable securities 55,212 — ( 42 ) 55,170 Long-term marketable securities U.S. treasuries 1,995 — ( 2 ) 1,993 Total long-term marketable securities 1,995 — ( 2 ) 1,993 Total $ 78,628 $ — $ ( 44 ) $ 78,584

Commitments and Contingencies (

Commitments and Contingencies (Tables)	9 Months Ended
	Sep. 30, 2022
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 September 30, Nine Months Ended September 30, 2022 2021 2022 2021 Operating lease cost $ 1,088 $ 1,087 $ 3,239 $ 3,274 Variable lease cost 407 393 1,114 1,246 Sublease income ( 1,391 ) ( 986 ) ( 3,405 ) ( 1,521 ) Total lease cost $ 104 $ 494 $ 948 $ 2,999
Summary of Supplemental Information Related to Leases	The following table summarizes supplemental information related to leases (in thousands): Nine Months Ended September 30, 2022 2021 Cash paid for amounts included in the measurement of lease liabilities Operating cash flows from operating leases $ 5,109 $ 4,978 Weighted-average remaining lease term (years) Operating leases 7.3 8.2 Weighted-average discount rate (percentage) Operating leases 6.0 % 5.9 %
Summary of Maturities of Lease Liabilities	The following table summarizes the maturities of lease liabilities as of September 30, 2022 (in thousands): Amount 2022 (remaining 3 months) $ 1,174 2023 4,810 2024 4,964 2025 5,123 2026 5,287 Thereafter 16,892 Total future minimum lease payments 38,250 Less: Amount representing interest ( 7,441 ) Present value of future minimum lease payments 30,809 Less: Current portion of operating lease liability ( 3,017 ) Noncurrent portion of operating lease liability $ 27,792

Term Loan Facility (Tables)

Term Loan Facility (Tables)	9 Months Ended
	Sep. 30, 2022
Debt Disclosure [Abstract]
Schedule of Future Principal Payments for Long-Term Debt	Future principal payments for the long-term debt as of September 30, 2022 are as follows (in thousands): Amount 2022 (for the remaining 3 months) $ — 2023 10,642 2024 9,358 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 ( 1,525 ) Present value of remaining debt payments 20,038 Current portion of long-term debt ( 6,776 ) Long-term debt, net $ 13,262

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2022
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 nine months ended September 30, 2022 is as follows: Number of Weighted- Balances at December 31, 2021 866,695 $ 60.47 Granted 215,314 $ 10.12 Canceled ( 168,986 ) $ 65.42 Balances at September 30, 2022 913,023 $ 47.68
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 nine months ended September 30, 2022 is as follows: Number of Weighted- Unvested at December 31, 2021 199,094 $ 39.22 Granted 46,332 $ 10.60 Vested ( 71,560 ) $ 40.42 Canceled ( 22,065 ) $ 35.98 Unvested at September 30, 2022 151,801 $ 30.39
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 September 30, Nine Months Ended September 30, 2022 2021 2022 2021 Research and development $ 799 $ 1,329 $ 2,723 $ 3,518 General and administrative 1,411 1,757 4,397 5,094 Total $ 2,210 $ 3,086 $ 7,120 $ 8,612

Net Loss per Common Share (Tabl

Net Loss per Common Share (Tables)	9 Months Ended
	Sep. 30, 2022
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 September 30, Nine Months Ended September 30, 2022 2021 2022 2021 Numerator: Net loss $ ( 13,708 ) $ ( 16,450 ) $ ( 45,758 ) $ ( 50,032 ) Denominator: Weighted-average number of shares 10,072,077 5,543,644 7,928,729 5,482,648 Net loss per share—basic and diluted $ ( 1.36 ) $ ( 2.97 ) $ ( 5.77 ) $ ( 9.13 )
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: September 30, 2022 2021 Options to purchase common stock 913,023 864,780 Warrants to purchase common stock 6,428,572 — Early exercised common stock subject to future vesting 3,337 3,337 RSUs 151,801 223,532 Shares subject to 2018 ESPP 9,255 8,077 Total 7,505,988 1,099,726

Organization - Additional Infor

Organization - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021	[1]
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Accumulated deficit	$ (445,784)						$ (445,784)		$ (400,024)
Net loss	(13,708)	$ (13,137)	$ (18,915)	$ (16,450)	$ (17,826)	$ (15,756)	(45,758)	$ (50,032)
Cash used in operations							(40,663)	(40,031)
Product revenue							0	$ 0
Cash, cash equivalents and marketable securities	$ 103,900						$ 103,900
[1] The balance sheet as of December 31, 2021 (as adjusted for the Reverse Split, as defined in Note 2) 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		9 Months Ended		12 Months Ended
	Oct. 19, 2022	Sep. 30, 2022 shares	Sep. 30, 2021	Sep. 30, 2022 Segment shares	Sep. 30, 2021	Dec. 31, 2021 shares
Reverse stock split ratio		0.1	0.1	0.1	0.1	0.1
Common stock, shares authorized | shares		300,000,000		300,000,000		300,000,000
Number of operating segment | Segment				1
Subsequent Event
Reverse stock split ratio	0.1

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	Sep. 30, 2022	Dec. 31, 2021
Assets:
Short-term marketable securities	$ 76,364	$ 55,170	[1]
Long-term marketable securities	4,980	1,993	[1]
Fair Value, Recurring
Assets:
Cash equivalents	15,883	21,421
Short-term marketable securities	76,364	55,170
Long-term marketable securities	4,980	1,993
Total assets subject to fair value measurements on a recurring basis	97,227	78,584
Fair Value, Recurring | Level 1
Assets:
Cash equivalents	5,934	21,421
Total assets subject to fair value measurements on a recurring basis	5,934	21,421
Fair Value, Recurring | Level 2
Assets:
Cash equivalents	9,949
Short-term marketable securities	76,364	55,170
Long-term marketable securities	4,980	1,993
Total assets subject to fair value measurements on a recurring basis	91,293	57,163
Money market funds | Fair Value, Recurring
Assets:
Cash equivalents	5,934	21,421
Money market funds | Fair Value, Recurring | Level 1
Assets:
Cash equivalents	5,934	21,421
U.S. Treasuries | Fair Value, Recurring
Assets:
Short-term marketable securities	40,002	52,146
Long-term marketable securities		1,993
U.S. Treasuries | Fair Value, Recurring | Level 2
Assets:
Short-term marketable securities	40,002	52,146
Long-term marketable securities		1,993
U.S. government debt securities | Fair Value, Recurring
Assets:
Cash equivalents	9,949
Short-term marketable securities	36,362	3,024
Long-term marketable securities	4,980
U.S. government debt securities | Fair Value, Recurring | Level 2
Assets:
Cash equivalents	9,949
Short-term marketable securities	36,362	$ 3,024
Long-term marketable securities	$ 4,980
[1] The balance sheet as of December 31, 2021 (as adjusted for the Reverse Split, as defined in Note 2) is derived from the audited financial statements as of that date.

Fair Value Measurements - Sum_2

Fair Value Measurements - Summary of Reconciliation of Derivative Liability Related to Debt Measured at Fair Value on a Recurring Basis Using Significant Unobservable Inputs (Details) - Fair Value, Recurring - Level 3 - Derivative Liability Related To Debt Conversion Feature $ in Thousands	9 Months Ended
	Sep. 30, 2022 USD ($)	[1]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Balance at December 31, 2021	$ 963
Conversion	(963)
Balance at June 30, 2022	$ 0
[1] Transfers into Level 3 related to the call option with Hercules Capital, Inc., where the lender can convert principal debt into common stock. Transfers out of Level 3 during the period related to the conversions calls of this option made by Hercules Capital, Inc.

Marketable Securities - Summary

Marketable Securities - Summary of Marketable Securities Classified as Available-for-Sale (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost Basis	$ 97,503	$ 78,628
Unrealized Gains	4	0
Unrealized Losses	(280)	(44)
Fair Value	97,227	78,584
Cash Equivalents
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost Basis	15,884	21,421
Unrealized Gains	0	0
Unrealized Losses	(1)	0
Fair Value	15,883	21,421
Cash Equivalents | Money market funds
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost Basis	5,934	21,421
Unrealized Gains	0	0
Unrealized Losses	0	0
Fair Value	5,934	21,421
Cash Equivalents | U.S. government debt securities
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost Basis	9,950
Unrealized Gains	0
Unrealized Losses	(1)
Fair Value	9,949
Short Term Marketable Securities
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost Basis	76,619	55,212
Unrealized Gains	4	0
Unrealized Losses	(259)	(42)
Fair Value	76,364	55,170
Short Term Marketable Securities | U.S. government debt securities
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost Basis	36,475	3,026
Unrealized Gains	4	0
Unrealized Losses	(117)	(2)
Fair Value	36,362	3,024
Short Term Marketable Securities | U S Treasuries
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost Basis	40,144	52,186
Unrealized Gains	0	0
Unrealized Losses	(142)	(40)
Fair Value	40,002	52,146
Long Term Marketable Securities
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost Basis	5,000	1,995
Unrealized Gains	0	0
Unrealized Losses	(20)	(2)
Fair Value	4,980	1,993
Long Term Marketable Securities | U.S. government debt securities
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost Basis	5,000
Unrealized Losses	(20)
Fair Value	$ 4,980
Long Term Marketable Securities | U S Treasuries
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost Basis		1,995
Unrealized Gains		0
Unrealized Losses		(2)
Fair Value		$ 1,993

Marketable Securities - Additio

Marketable Securities - Additional Information (Details) - USD ($)	9 Months Ended	12 Months Ended
	Sep. 30, 2022	Dec. 31, 2021
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	2 years

License Revenue and Agreements

License Revenue and Agreements - Additional Information (Details) - USD ($)		1 Months Ended		3 Months Ended		9 Months Ended		12 Months Ended
		Jun. 30, 2021	Jun. 30, 2019	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021		Aug. 31, 2021	Dec. 31, 2020
Research And Development Arrangement Contract To Perform For Others [Line Items]
Revenue recognized				$ 0	$ 0	$ 236,000	$ 0
Deferred revenue				$ 0		$ 0		$ 216,000	[1]
Compound library and option agreement execution month and year						2016-02
Compound library and option agreement expiration month and year						2022-02
Common stock, shares issued				14,036,249		14,036,249		6,299,191
Common stock, value	[2]			$ 1,000		$ 1,000		$ 1,000	[1]
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	200,000	$ 0
Deferred revenue				0		0		200,000
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		$ 0		$ 0
Maximum milestone payments for each product licensed under agreement			$ 13,600,000
Other Licensing Agreements with Research Institutions | UCSF | Common Stock
Research And Development Arrangement Contract To Perform For Others [Line Items]
Issuance of common stock (in shares)			12,000
Other Licensing Agreements with Research Institutions | UCSF | Additional Paid-In Capital
Research And Development Arrangement Contract To Perform For Others [Line Items]
Issuance of common stock, net of issuance costs			$ 1,000,000
Commercial Agreements | Ascentage Pharma
Research And Development Arrangement Contract To Perform For Others [Line Items]
Milestone payments		$ 2,000,000
Equity payments percentage						80%
Common stock, shares issued				126,975		126,975				29,477	36,166
Common stock fair market value, net of withholding taxes										$ 1,100,000
Common stock, value											$ 2,300,000
Contingent consideration liability				$ 0		$ 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 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%
Common stock, shares issued				29,194		29,194				10,527
Common stock fair market value										$ 400,000
[1] The balance sheet as of December 31, 2021 (as adjusted for the Reverse Split, as defined in Note 2) 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 where every ten shares of its common stock issued and outstanding was converted into one share of 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.

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details)	1 Months Ended				3 Months Ended		9 Months Ended		12 Months Ended
	May 31, 2022 ft² $ / ft²	Jun. 30, 2021 ft² $ / ft²	May 31, 2021 ft² $ / ft²	Feb. 28, 2021 USD ($) ft² $ / ft²	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Commitments And Contingencies [Line Items]
Sublease income					$ 1,391,000	$ 986,000	$ 3,405,000	$ 1,521,000
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
Lease commencement date							2019-05
Lease expiration date							Dec. 31, 2029
Operating lease, initial lease term					10 years		10 years
Operating lease, option to extend description							option to extend the term for an additional eight years
Operating lease, existence of option to extend							true
Operating lease, renewal term					8 years		8 years
Tenant improvement allowance										$ 10,700,000
Letter of credit delivered in connection with lease agreement					$ 900,000		$ 900,000
Estimated discount rate					3.50%		3.50%
Impairment loss					$ 0		$ 0		$ 2,600,000
Space subleased (in sqaure feet) | ft²	15,000	23,000
Sublease expiration date	Jun. 30, 2024	Aug. 31, 2024
Sublease rent per square foot | $ / ft²	7.80	6.25
Annual percentage increase in sublease base rent	3.50%	3.50%
Percentage of operating expenses and property management fees to be paid by subtenant		37%	24%
Sublease income					$ 1,000,000	500,000	$ 2,100,000	500,000
Sublease start date	Jul. 01, 2022
Brisbane, California
Commitments And Contingencies [Line Items]
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.
Operating lease, renewal term					4 years		4 years
Tenant improvement allowance					$ 3,900,000		$ 3,900,000
Lease expiration date							2022-10
Space subleased (in sqaure feet) | ft²			11,500	27,000
Sublease expiration date			Sep. 30, 2022	Aug. 31, 2022
Sublease rent per square foot | $ / ft²			1	3.53
Annual percentage increase in sublease base rent				3%
Percentage of operating expenses and property management fees to be paid by subtenant			30%	41%
Incurred initial direct costs of sublease				$ 100,000
Sublease income					$ 400,000	$ 500,000	$ 1,300,000	$ 1,000,000

Commitments and Contingencies_2

Commitments and Contingencies - Summary of Components of Lease Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Lease, Cost [Abstract]
Operating lease cost	$ 1,088	$ 1,087	$ 3,239	$ 3,274
Variable lease cost	407	393	1,114	1,246
Sublease income	(1,391)	(986)	(3,405)	(1,521)
Total lease cost	$ 104	$ 494	$ 948	$ 2,999

Commitments and Contingencies_3

Commitments and Contingencies - Summary of Supplemental Information Related to Leases (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Commitments And Contingencies Disclosure [Abstract]
Operating cash flows from operating leases	$ 5,109	$ 4,978
Operating leases, Weighted-average remaining lease term (years)	7 years 3 months 18 days	8 years 2 months 12 days
Operating leases, Weighted-average discount rate (percentage)	6%	5.90%

Commitments and Contingencies_4

Commitments and Contingencies - Summary of Maturities of Lease Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021	[1]
Commitments And Contingencies Disclosure [Abstract]
2022 (remaining 3 months)	$ 1,174
2023	4,810
2024	4,964
2025	5,123
2026	5,287
Thereafter	16,892
Total future minimum lease payments	38,250
Less: Amount representing interest	(7,441)
Present value of future minimum lease payments	30,809
Less: Current portion of operating lease liability	(3,017)
Noncurrent portion of operating lease liability	$ 27,792	$ 30,094
[1] The balance sheet as of December 31, 2021 (as adjusted for the Reverse Split, as defined in Note 2) is derived from the audited financial statements as of that date.

Term Loan Facility - Additional

Term Loan Facility - Additional Information (Details) $ in Thousands					3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 22, 2022	Jul. 28, 2022	Dec. 15, 2021 USD ($)	Aug. 03, 2020 USD ($) Tranche	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)	Dec. 31, 2021 USD ($)	Jul. 01, 2021 USD ($)
Debt Instrument [Line Items]
Debt instrument aggregate principal amount					$ 20,000		$ 20,000
Unamortized discount and debt issuance costs					1,525		1,525
End of term fee due at maturity					1,563		1,563
Interest expense					866	$ 792	2,568	$ 2,351
Term Loan | Loan Agreement | Hercules Capital
Debt Instrument [Line Items]
Debt instrument aggregate principal amount					20,000		20,000
Number of tranches | Tranche				4
Principal amount of first tranche				$ 25,000	$ 20,000		20,000
Debt conversion, original debt amount							$ 2,700		$ 2,300
Loan issuance cost									$ 100
Long-term debt, maturity date					Aug. 01, 2024		Aug. 01, 2024
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 July 28, 2022, the prime rate was raised to 5.50% and on September 22, 2022, the prime rate was raised again to 6.25%. On September 30, 2022, the interest rate on the term loan was 12.35%. Interest expense is calculated using the effective interest method and is inclusive of non-cash amortization of capitalized loan issuance costs. At September 30, 2022, the effective interest rate was 18.90%.
Debt instrument, interest rate, stated percentage					12.35%		12.35%
Debt instrument, interest rate, effective percentage					18.90%		18.90%
Maximum amount of debt that can be purchased by lender.							$ 2,000
Debt instrument, minimum unrestricted cash										$ 15,000
Unamortized discount and debt issuance costs					$ 1,500		1,500
End of term fee due at maturity					1,600		1,600
Term Loan | Loan Agreement | Hercules Capital | Interest And Other Expense
Debt Instrument [Line Items]
Interest expense					$ 900	$ 800	$ 2,600	$ 2,400
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%
Debt instrument, interest rate during period	6.25%	5.50%
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 percentage of principal amount			20%
Debt conversion, original debt amount			$ 5,000
Prepayment fee							1.50%
Term Loan | Loan Agreement | Hercules Capital | Minimum
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage					9.35%		9.35%

Term Loan Facility - Schedule o

Term Loan Facility - Schedule of Future Principal Payments for Long-Term Debt (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021	[1]
Debt Disclosure [Abstract]
2022 (for the remaining 3 months)	$ 0
2023	10,642
2024	9,358
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	(1,525)
Present value of remaining debt payments	20,038
Current portion of long-term debt	(6,776)	$ (3,055)
Long-term debt, net	$ 13,262	$ 18,409
[1] The balance sheet as of December 31, 2021 (as adjusted for the Reverse Split, as defined in Note 2) is derived from the audited financial statements as of that date.

Related-Party Transactions - Ad

Related-Party Transactions - Additional Information (Details) - License Agreement - Jocasta Neuroscience Inc - USD ($)	1 Months Ended	3 Months Ended		9 Months Ended		12 Months Ended
	Dec. 31, 2021	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Related Party Transaction [Line Items]
Upfront cash payments received	$ 5,000,000
Deferred revenue recognized		$ 0	$ 0	$ 200,000	$ 0	$ 4,800,000

Equity Financing - Additional I

Equity Financing - Additional Information (Details) - USD ($)

1 Months Ended

3 Months Ended

9 Months Ended

12 Months Ended

Aug. 22, 2022

Aug. 17, 2022

Sep. 29, 2021

Oct. 31, 2022

Mar. 31, 2022

Sep. 30, 2022

Jun. 30, 2022

Mar. 31, 2022

Sep. 30, 2021

Mar. 31, 2021

Sep. 30, 2022

Sep. 30, 2021

Dec. 31, 2021

Subsidiary Sale Of Stock [Line Items]

Equity financing, authorized amount

$ 125,000,000

Common stock, par value

$ 0.0001

$ 0.0001

$ 0.0001

Other expense related to transaction with Lincoln Park Capital Fund

$ 0

$ 825,000

Subsequent Event

Subsidiary Sale Of Stock [Line Items]

Equity financing, authorized amount

$ 250,000,000

March 2022 Sales Agreement

Subsidiary Sale Of Stock [Line Items]

Common stock amount remained available for sale

$ 16,100,000

$ 16,100,000

Cowen | October 2022 Sales Agreement | Subsequent Event

Subsidiary Sale Of Stock [Line Items]

Percentage of gross sales proceeds of common stock payable as compensation

3%

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

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 | Warrants

Subsidiary Sale Of Stock [Line Items]

Warrants issued to purchase ordinary shares

6,428,572

Exercise price for warrant

$ 8.50

Follow-On Offering | Common Stock

Subsidiary Sale Of Stock [Line Items]

Issuance of common stock (in shares)

6,428,571

Share purchase price

$ 7

August 2022 Offering

Subsidiary Sale Of Stock [Line Items]

Proceeds from sale of common stock

$ 41,650,000

0

Issuance of common stock, value

$ 41,650,000

August 2022 Offering | Common Stock

Subsidiary Sale Of Stock [Line Items]

Issuance of common stock (in shares)

[1]

6,428,571

At The Market Equity Offering Program

Subsidiary Sale Of Stock [Line Items]

Proceeds from sale of common stock

12,003,000

8,892,000

Issuance of common stock, value

$ 8,570,000

$ 13,000

$ 3,420,000

$ 8,892,000

At The Market Equity Offering Program | March 2022 Sales Agreement

Subsidiary Sale Of Stock [Line Items]

Proceeds from sale of common stock

8,600,000

8,600,000

Payments for other offering expenses

$ 300,000

$ 300,000

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

Subsidiary Sale Of Stock [Line Items]

Equity financing, authorized amount

$ 25,000,000

$ 50,000,000

At The Market Equity Offering Program | Common Stock

Subsidiary Sale Of Stock [Line Items]

Issuance of common stock (in shares)

633,464

[1]

232,500

[1]

122,063

[2]

At The Market Equity Offering Program | Common Stock | March 2022 Sales Agreement

Subsidiary Sale Of Stock [Line Items]

Issuance of common stock (in shares)

633,464

633,464

At The Market Equity 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%

At The Market Equity Offering Program | Common Stock | Cowen | March 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

100,000

300,000

Share purchase price

$ 2.94

Proceeds from sale of common stock

$ 910,000

$ 2,901,000

Issuance of common stock, value

$ 910,000

$ 3,726,000

Purchase agreement term

36 months

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

$ 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

$ 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

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

$ 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)

25,244

90,000

[1]

127,286

[2]

Proceeds from sale of common stock

$ 900,000

$ 5,300,000

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

[1] The Company effected a reverse stock split of its outstanding shares of common stock where every ten shares of its common stock issued and outstanding was converted into one share of 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. The Company effected a reverse stock split of its outstanding shares of common stock where every ten shares of its common stock issued and outstanding was converted into one share of 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.

Corporate Restructuring - Addit

Corporate Restructuring - Additional Information (Details) $ in Millions	1 Months Ended	9 Months Ended
	Feb. 28, 2022 Position	Sep. 30, 2022 USD ($)
Restructuring Cost And Reserve [Line Items]
Restructuring implementation date	2022-02
Number of positions eliminated | Position	29
Percentage of positions eliminated	50%
Severance charge in operating expenses		$ 1.9
Non-cash share-based payment compensation credits to forfeiture of stock options		1.2
Employee Termination Benefits
Restructuring Cost And Reserve [Line Items]
Severance charge in operating expenses		1.6
Employee Termination Benefits | Research And Development Expense
Restructuring Cost And Reserve [Line Items]
Severance charge in operating expenses		1.4
Employee Termination Benefits | Employee-Related Benefits
Restructuring Cost And Reserve [Line Items]
Severance charge in operating expenses		0.2
Employee Termination Benefits | General And Administrative Expense
Restructuring Cost And Reserve [Line Items]
Severance charge in operating expenses		0.5
Employee Termination Benefits | Payroll Taxes
Restructuring Cost And Reserve [Line Items]
Severance charge in operating expenses		$ 0.1

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Stock Option Activity (Details)	9 Months Ended
	Sep. 30, 2022 $ / shares shares
Number of Shares
Balances at December 31, 2021 | shares	866,695
Granted | shares	215,314
Canceled | shares	(168,986)
Balances at September 30, 2022 | shares	913,023
Weighted-Average Exercise Price
Balances at December 31, 2021 | $ / shares	$ 60.47
Granted | $ / shares	10.12
Canceled | $ / shares	65.42
Balances at September 30, 2022 | $ / shares	$ 47.68

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	9 Months Ended
	Sep. 30, 2022 $ / shares shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares, Unvested at December 31, 2021 | shares	199,094
Shares, Granted | shares	46,332
Shares, Vested | shares	(71,560)
Shares, Canceled | shares	(22,065)
Shares, Unvested at September 30, 2022 | shares	151,801
Weighted-Average Grant Date Fair Value, Unvested at December 31, 2021 | $ / shares	$ 39.22
Weighted-Average Grant Date Fair Value, Granted | $ / shares	10.60
Weighted-Average Grant Date Fair Value, Vested | $ / shares	40.42
Weighted-Average Grant Date Fair Value, Canceled | $ / shares	35.98
Weighted-Average Grant Date Fair Value, Unvested at September 30, 2022 | $ / shares	$ 30.39

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Details) - USD ($)	1 Months Ended				3 Months Ended		9 Months Ended
	Feb. 28, 2022	Jun. 30, 2021	Jan. 31, 2021	Mar. 31, 2020	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares options granted to purchase an aggregate of common stock							215,314
Compensation cost recognized				$ 200,000
Stock option awards outstanding					913,023		913,023		866,695
Stock based compensation expense for liability awards					$ 0	$ 0	$ 0	$ 0
Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of retention awards granted	189,333
Retention award grant date total fair value	$ 2,000,000
RSUs
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of retention awards granted	46,332
Retention award grant date total fair value	$ 500,000
Performance and Market Contingent Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Trailing period		30 days
Modification date fair value		$ 102,000	$ 81,000
Implied service period for recognition		1 year 10 months 6 days
Stock option awards outstanding					3,337		3,337
Stock option awards, grant date fair value					$ 100,000		$ 100,000
Performance and Market Contingent Stock Options | Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Implied service period for recognition			1 year 5 months 15 days
Attaining valuation of certain amount		$ 1,000,000,000
Performance and Market Contingent Stock Options | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Implied service period for recognition			2 years 6 months 7 days
Performance and Market Contingent Stock Options | Tranche One
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Volume-weighted average per Share closing trading price			$ 180
Trailing period			30 days
Performance and Market Contingent Stock Options | Tranche Two
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Volume-weighted average per Share closing trading price			$ 360
Trailing period			30 days
Performance and Market Contingent Stock Options | Executive Team
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock option awards exercisable upon the achievement of performance goals		3,337	1,747
2020 Employment Inducement Incentive Plan | New Chief Executive Officer
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of common stock shares granted				100,000
2020 Employment Inducement Incentive Plan | Stock Options | New Chief Executive Officer
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares options granted to purchase an aggregate of common stock				80,000
2020 Employment Inducement Incentive Plan | PSUs
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Grant date fair value				$ 700,000
Weighted-average derived service period for recognition				4 years 3 months 18 days
Incremental fair value on modification date			$ 31,000
Unamortized value of original grant			$ 569,000
2020 Employment Inducement Incentive Plan | PSUs | Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
New implied service period for recognition				1 year 7 months 17 days
2020 Employment Inducement Incentive Plan | PSUs | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
New implied service period for recognition				2 years 9 months 14 days
2020 Employment Inducement Incentive Plan | PSUs | Tranche One
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares to vest upon attainment of certain conditions			5,000	5,000
Volume-weighted average per Share closing trading price			$ 180	$ 368.75
Trailing period			30 days	30 days
Price per share to holders of company's common stock				$ 368.75
2020 Employment Inducement Incentive Plan | PSUs | Tranche Two
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares to vest upon attainment of certain conditions			10,000	10,000
Trailing period			30 days	30 days
Price per share to holders of company's common stock			$ 360
Market capitalization trigger				$ 2,500,000,000
2020 Employment Inducement Incentive Plan | PSUs | New Chief Executive Officer
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares options granted to purchase an aggregate of common stock				15,000
2020 Employment Inducement Incentive Plan | RSUs and Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting rights				The stock options and RSUs will vest subject to continued service through the applicable vesting date.
2020 Employment Inducement Incentive Plan | RSUs | New Chief Executive Officer
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of common stock shares granted				12,000
2020 Employment Inducement Incentive Plan | Common Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares vested				3,000
2020 Employment Inducement Incentive Plan | Common Stock | New Chief Executive Officer
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of common stock shares granted				3,000

Stock-Based Compensation - Su_3

Stock-Based Compensation - Summary of Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 2,210	$ 3,086	$ 7,120	$ 8,612
Research And Development Expense
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	799	1,329	2,723	3,518
General And Administrative Expense
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 1,411	$ 1,757	$ 4,397	$ 5,094

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						9 Months Ended
		Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2022	Sep. 30, 2021
Numerator:
Net loss		$ (13,708)	$ (13,137)	$ (18,915)	$ (16,450)	$ (17,826)	$ (15,756)	$ (45,758)	$ (50,032)
Denominator:
Weighted-average number of shares outstanding—basic	[1]	10,072,077			5,543,644			7,928,729	5,482,648
Weighted-average number of shares outstanding—diluted	[1]	10,072,077			5,543,644			7,928,729	5,482,648
Net loss per share, basic		$ (1.36)			$ (2.97)			$ (5.77)	$ (9.13)
Net loss per share, diluted		$ (1.36)			$ (2.97)			$ (5.77)	$ (9.13)
[1] The Company effected a reverse stock split of its outstanding shares of common stock where every ten shares of its common stock issued and outstanding was converted into one share of 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.

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	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of diluted net loss per share	7,505,988	1,099,726
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	913,023	864,780
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	3,337	3,337
RSUs
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of diluted net loss per share	151,801	223,532
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	9,255	8,077

Net Loss per Common Share - Add

Net Loss per Common Share - Additional Information (Details)	9 Months Ended
	Sep. 30, 2022 shares
Maximum
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Shares contingently issued	5,590

Defined Contribution Plan - Add

Defined Contribution Plan - Additional Information (Details) - Defined Contribution Plan - USD ($) $ in Millions	1 Months Ended	3 Months Ended		9 Months Ended
	Jan. 31, 2019	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
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	$ 0.1	$ 0.4	$ 0.4

Subsequent Events - Additional

Subsequent Events - Additional Information (Details)		1 Months Ended			3 Months Ended		9 Months Ended		12 Months Ended
	Oct. 19, 2022	Nov. 08, 2022 USD ($) shares	Oct. 31, 2022 USD ($)	Mar. 31, 2022 USD ($)	Sep. 30, 2022 shares	Sep. 30, 2021	Sep. 30, 2022 USD ($) shares	Sep. 30, 2021 USD ($)	Dec. 31, 2021 shares
Subsequent Event [Line Items]
Reverse stock split ratio					0.1	0.1	0.1	0.1	0.1
Common stock, shares authorized | shares					300,000,000		300,000,000		300,000,000
Equity financing, authorized amount				$ 125,000,000
Common stock sold and issued | shares					14,036,249		14,036,249		6,299,191
ATM Offering Program
Subsequent Event [Line Items]
Proceeds from sale of common stock							$ 12,003,000	$ 8,892,000
Subsequent Event
Subsequent Event [Line Items]
Reverse stock split ratio	0.1
Equity financing, authorized amount			$ 250,000,000
Subsequent Event | March 2022 ATM Offering Program
Subsequent Event [Line Items]
Common stock sold and issued | shares		153,082
Proceeds from sale of common stock		$ 500,000
Commissions and other offering expenses		$ 100,000
Subsequent Event | Cowen | October 2022 Sales Agreement
Subsequent Event [Line Items]
Percentage of gross sales proceeds of common stock payable as compensation			3%
Subsequent Event | Maximum | Cowen | ATM Offering Program | October 2022 Sales Agreement
Subsequent Event [Line Items]
Aggregate gross sales proceeds			$ 50,000,000