Spyre Therapeutics (SYRE) 10-Q 3 Nov 22 2022 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2022	Oct. 28, 2022
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2022
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q3
Trading Symbol	AGLE
Security Exchange Name	NASDAQ
Entity Registrant Name	AEGLEA BIOTHERAPEUTICS, INC.
Entity Central Index Key	0001636282
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity File Number	001-37722
Entity Tax Identification Number	46-4312787
Entity Address, Address Line One	805 Las Cimas Parkway
Entity Address, Address Line Two	Suite 100
Entity Address, City or Town	Austin
Title of 12(b) Security	Common Stock, $0.0001 Par Value Per Share
Entity Address, Postal Zip Code	78746
City Area Code	512
Local Phone Number	942-2935
Entity Address, State or Province	TX
Entity Incorporation, State or Country Code	DE
Entity Shell Company	false
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Interactive Data Current	Yes
Entity Current Reporting Status	Yes
Document Quarterly Report	true
Document Transition Report	false
Entity Common Stock, Shares Outstanding		61,511,078

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (unaudited) - USD ($) $ in Thousands	Sep. 30, 2022	Jun. 30, 2022	Dec. 31, 2021
CURRENT ASSETS
Cash and cash equivalents	$ 38,989		$ 15,142
Marketable securities	34,687		77,986
License and development receivables	669		815
Prepaid expenses and other current assets	7,874		4,948
Total current assets	82,219		98,891
Restricted cash	1,529		1,838
Property and equipment, net	3,555		4,549
Operating lease right-of-use assets	3,514		3,806
Other non-current assets	749		842
TOTAL ASSETS	91,566		109,926
CURRENT LIABILITIES
Accounts payable	4,178		3,319
Operating lease liabilities	587		436
Deferred revenue	505		2,359
Accrued and other current liabilities	12,408		14,030
Total current liabilities	17,678		20,144
Non-current operating lease liabilities	4,159		4,608
Deferred revenue, net of current portion	2,174		1,217
Other non-current liabilities	0		16
TOTAL LIABILITIES	24,011		25,985
Commitments and Contingencies (Note 7)
STOCKHOLDERS’ EQUITY
Preferred stock, $0.0001 par value; 10,000,000 shares authorized as of September 30, 2022 and December 31, 2021; no shares issued and outstanding as of September 30, 2022 and December 31, 2021	0		0
Common stock, $0.0001 par value; 500,000,000 shares authorized as of September 30, 2022 and December 31, 2021; 61,511,078 shares and 49,355,130 shares issued and outstanding as of September 30,2022 and December 31, 2021, respectively	6		5
Additional paid-in capital	474,535		425,765
Accumulated other comprehensive loss	(184)		(20)
Accumulated deficit	(406,802)		(341,809)
TOTAL STOCKHOLDERS’ EQUITY	67,555	$ 84,157	83,941
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	$ 91,566		$ 109,926

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (unaudited) (Parenthetical) - $ / shares	Sep. 30, 2022	Dec. 31, 2021
Statement Of Financial Position [Abstract]
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	500,000,000	500,000,000
Common stock, shares issued	61,511,078	49,355,130
Common stock, shares outstanding	61,511,078	49,355,130

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Revenue:
Total revenue	$ 174	$ 1,399	$ 2,161	$ 15,095
Operating expenses:
Research and development	11,977	14,853	44,328	40,287
General and administrative	6,952	6,839	23,452	20,015
Total operating expenses	18,929	21,692	67,780	60,302
Loss from operations	(18,755)	(20,293)	(65,619)	(45,207)
Other income (expense):
Interest income	288	36	427	77
Other income (expense), net	24	(24)	25	(107)
Total other income (expense)	312	12	452	(30)
Loss before income tax expense	(18,443)	(20,281)	(65,167)	(45,237)
Income tax benefit (expense)	209	(26)	174	(118)
Net loss	$ (18,234)	$ (20,307)	$ (64,993)	$ (45,355)
Net loss per share, basic	$ (0.19)	$ (0.31)	$ (0.81)	$ (0.69)
Weighted-average common shares outstanding, basic	94,197,958	65,789,449	80,574,683	65,675,915
Net loss per share, diluted	$ (0.19)	$ (0.31)	$ (0.81)	$ (0.69)
Weighted-average common shares outstanding, diluted	94,197,958	65,789,449	80,574,683	65,675,915
License [Member]
Revenue:
Total revenue	$ 0	$ 0	$ 0	$ 12,000
Development Fee [Member]
Revenue:
Total revenue	$ 174	$ 1,399	$ 2,161	$ 3,095

Condensed Consolidated Statem_2

Condensed Consolidated Statements of 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]
Net loss	$ (18,234)	$ (20,307)	$ (64,993)	$ (45,355)
Other comprehensive income (loss):
Foreign currency translation adjustment	(38)	(10)	(87)	(4)
Unrealized gain (loss) on marketable securities	74	1	(77)	(5)
Total comprehensive loss	$ (18,198)	$ (20,316)	$ (65,157)	$ (45,364)

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Changes in Stockholders' Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit
Balances at Dec. 31, 2020	$ 139,832	$ 5	$ 415,824	$ 11	$ (276,008)
Balances (in shares) at Dec. 31, 2020		47,959
Issuance of common stock in connection with employee stock purchase plan	224		224
Issuance of common stock in connection with employee stock purchase plan (in shares)		38
Issuance of common stock in connection with exercise of stock options	146		146
Issuance of common stock in connection with exercise of stock options (in shares)		23
Issuance of common stock in connection with exercise of pre-funded warrants (in shares)		1,000
Stock-based compensation expense	1,757		1,757
Foreign currency translation adjustment	4			4
Unrealized gain (loss) on marketable securities	10			10
Net loss	(18,218)				(18,218)
Balances at Mar. 31, 2021	123,755	$ 5	417,951	25	(294,226)
Balances (in shares) at Mar. 31, 2021		49,020
Balances at Dec. 31, 2020	139,832	$ 5	415,824	11	(276,008)
Balances (in shares) at Dec. 31, 2020		47,959
Foreign currency translation adjustment	(4)
Unrealized gain (loss) on marketable securities	(5)
Net loss	(45,355)
Balances at Sep. 30, 2021	102,081	$ 5	423,437	2	(321,363)
Balances (in shares) at Sep. 30, 2021		49,306
Balances at Mar. 31, 2021	123,755	$ 5	417,951	25	(294,226)
Balances (in shares) at Mar. 31, 2021		49,020
Issuance of common stock in connection with exercise of stock options	33		33
Issuance of common stock in connection with exercise of stock options (in shares)		6
Stock-based compensation expense	2,080		2,080
Foreign currency translation adjustment	2			2
Unrealized gain (loss) on marketable securities	(16)			(16)
Net loss	(6,830)				(6,830)
Balances at Jun. 30, 2021	119,024	$ 5	420,064	11	(301,056)
Balances (in shares) at Jun. 30, 2021		49,026
Issuance of common stock in connection with employee stock purchase plan	230		230
Issuance of common stock in connection with employee stock purchase plan (in shares)		45
Issuance of common stock in connection with exercise of stock options	1,036		1,036
Issuance of common stock in connection with exercise of stock options (in shares)		235
Stock-based compensation expense	2,107		2,107
Foreign currency translation adjustment	(10)			(10)
Unrealized gain (loss) on marketable securities	1			1
Net loss	(20,307)				(20,307)
Balances at Sep. 30, 2021	102,081	$ 5	423,437	2	(321,363)
Balances (in shares) at Sep. 30, 2021		49,306
Balances at Dec. 31, 2021	83,941	$ 5	425,765	(20)	(341,809)
Balances (in shares) at Dec. 31, 2021		49,355
Issuance of common stock in connection with employee stock purchase plan	184		184
Issuance of common stock in connection with employee stock purchase plan (in shares)		65
Stock-based compensation expense	2,101		2,101
Foreign currency translation adjustment	(13)			(13)
Unrealized gain (loss) on marketable securities	(120)			(120)
Net loss	(24,436)				(24,436)
Balances at Mar. 31, 2022	61,657	$ 5	428,050	(153)	(366,245)
Balances (in shares) at Mar. 31, 2022		49,420
Balances at Dec. 31, 2021	83,941	$ 5	425,765	(20)	(341,809)
Balances (in shares) at Dec. 31, 2021		49,355
Foreign currency translation adjustment	(87)
Unrealized gain (loss) on marketable securities	(77)
Net loss	(64,993)
Balances at Sep. 30, 2022	67,555	$ 6	474,535	(184)	(406,802)
Balances (in shares) at Sep. 30, 2022		61,511
Balances at Mar. 31, 2022	61,657	$ 5	428,050	(153)	(366,245)
Balances (in shares) at Mar. 31, 2022		49,420
Issuance of common stock and pre-funded warrants in connection with public offering, net of offering costs	42,873	$ 1	42,872
Issuance of common stock and pre-funded warrants in connection with registered direct offering, net of offering costs (in shares)		10,753
Issuance of common stock in connection with exercise of pre-funded warrants (in shares)		1,000
Stock-based compensation expense	2,017		2,017
Foreign currency translation adjustment	(36)			(36)
Unrealized gain (loss) on marketable securities	(31)			(31)
Net loss	(22,323)				(22,323)
Balances at Jun. 30, 2022	84,157	$ 6	472,939	(220)	(388,568)
Balances (in shares) at Jun. 30, 2022		61,173
Issuance of common stock in connection with employee stock purchase plan	38		38
Issuance of common stock in connection with employee stock purchase plan (in shares)		87
Issuance of common stock in connection with registered direct offering, net of offering costs	(8)		(8)
Issuance of common stock in connection with exercise of pre-funded warrants (in shares)		251
Stock-based compensation expense	1,566		1,566
Foreign currency translation adjustment	(38)			(38)
Unrealized gain (loss) on marketable securities	74			74
Net loss	(18,234)				(18,234)
Balances at Sep. 30, 2022	$ 67,555	$ 6	$ 474,535	$ (184)	$ (406,802)
Balances (in shares) at Sep. 30, 2022		61,511

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
CASH FLOWS FROM OPERATING ACTIVITIES
Net loss	$ (64,993)	$ (45,355)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	1,182	1,165
Stock-based compensation	5,684	5,944
Purchase net premium on marketable securities	351	(374)
Non-cash operating lease expense	292	334
Net amortization of premium (accretion of discount) on marketable securities	(175)	490
Other	0	2
Changes in operating assets and liabilities:
Accounts payable	859	(390)
License and development receivables	146	0
Prepaid expenses and other assets	(2,863)	(1,555)
Accrued and other liabilities	(1,293)	(828)
Deferred revenue	(897)	6,405
Operating lease liabilities	(297)	(286)
Net cash used in operating activities	(62,004)	(34,448)
CASH FLOWS FROM INVESTING ACTIVITIES
Purchases of property and equipment	(38)	(573)
Purchases of marketable securities	(35,000)	(119,829)
Proceeds from maturities and sales of marketable securities	78,046	88,120
Net cash provided by (used in) investing activities	43,008	(32,282)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from issuance of common stock and pre-funded warrants in registered direct offering, net of offering costs	42,874	0
Proceeds from employee stock plan purchases and stock option exercises	222	1,654
Principal payments on finance lease obligation	(410)	(341)
Net cash provided by financing activities	42,686	1,313
Effect of exchange rate on cash, cash equivalents, and restricted cash	(152)	(18)
NET INCREASE (DECREASE) IN CASH, CASH EQUIVALENTS, AND RESTRICTED CASH	23,538	(65,435)
CASH, CASH EQUIVALENTS, AND RESTRICTED CASH
Beginning of period	16,980	91,937
End of period	40,518	26,502
Supplemental Disclosure of Non-Cash Investing and Financing Information:
Leased assets obtained in exchange for lease obligations	$ 0	$ 872

The Company and Basis of Presen

The Company and Basis of Presentation	9 Months Ended
	Sep. 30, 2022
Organization Consolidation And Presentation Of Financial Statements [Abstract]
The Company and Basis of Presentation	1. The Company and Basis of Presentation Aeglea BioTherapeutics, Inc. (“Aeglea” or the “Company”) is a clinical-stage biotechnology company redefining the potential of human enzyme therapeutics to benefit people with rare metabolic diseases with limited treatment options. The Company was formed as a Limited Liability Company ("LLC") in Delaware on December 16, 2013 under the name Aeglea BioTherapeutics Holdings, LLC and was converted from a Delaware LLC to a Delaware corporation on March 10, 2015. The Company operates in one segment and has its principal offices in Austin, Texas. Liquidity As of September 30, 2022, the Company had working capital of $ 64.5 million, an accumulated deficit of $ 406.8 million, and cash, cash equivalents, marketable securities, and restricted cash of $ 75.2 million. The Company has not generated any product revenues and has not achieved profitable operations. There is no assurance that profitable operations will ever be achieved, and, if achieved, could be sustained on a continuing basis. In addition, development activities, clinical and nonclinical testing, and commercialization of the Company’s products will require significant additional financing. The Company is subject to a number of risks similar to other life science companies, including, but not limited to, risks related to the successful discovery, development, and commercialization of product candidates, raising additional capital, development of competing drugs and therapies, protection of proprietary technology and market acceptance of the Company’s products. As a result of these and other factors and the related uncertainties, there can be no assurance of the Company’s future success. In accordance with Accounting Standard Codification ("ASC") 205-40, Going Concern, the Company has evaluated whether there are conditions and events, considered in the aggregate, that raise substantial doubt about the Company’s ability to continue as a going concern within one year after the date the financial statements are issued. Based upon the Company’s current operating plans, the Company believes that it has sufficient resources to fund operations into the fourth quarter of 2023 with its existing cash, cash equivalents, and marketable securities. Accordingly, based on its recurring losses from operations incurred since inception, the expectation of continued operating losses, and the need to raise additional capital to finance its future operations, the Company determined that there is substantial doubt about the Company’s ability to continue as a going concern within twelve months of the issuance date of these financial statements. The accompanying condensed consolidated financial statements do not include any adjustments that might result from the outcome of this uncertainty and assumes the Company will continue as a going concern through the realization of assets and satisfaction of liabilities and commitments in the ordinary course of business. The Company plans to address this condition through the sale of common stock in public offerings and/or private placements, debt financings, or through other capital sources, including collaborations with other companies or other strategic transactions. Although the Company has been successful in raising capital in the past, there is no assurance that it will be successful in obtaining such additional financing on terms acceptable to the Company, if at all, nor is it considered probable under the accounting standards. If the Company is unable to obtain sufficient funding on acceptable terms, it could be forced to delay, reduce or eliminate some or all of its research and development programs or commercialization activities, which could materially adversely affect its business prospects or its ability to continue operations. Unaudited Interim Financial Information The interim condensed consolidated financial statements included in this document are unaudited. The unaudited interim financial statements have been prepared on the same basis as the annual financial statements and reflect, in the opinion of management, all adjustments of a normal and recurring nature that are necessary for a fair statement of 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, changes in stockholders’ equity 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 of operations for the three and nine months ended September 30, 2022, are not necessarily indicative of the results to be expected for the year ending December 31, 2022 or for any other future annual or interim period. The December 31, 2021 balance sheet was derived from audited financial statements, but does not include all disclosures required by accounting principles generally accepted in the United States (“U.S. GAAP”). These financial statements should be read in conjunction with the audited financial statements included in the Company’s Form 10-K for the year ended December 31, 2021 as filed with the Securities and Exchange Commission ("SEC").

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 Summary of Significant Accounting Policies These interim condensed consolidated financial statements have been prepared in accordance with U.S. GAAP and SEC instructions for interim financial information, and should be read in conjunction with the Company's Annual Report on Form 10-K for the year ended December 31, 2021 (“Annual Report”). Significant accounting policies and other disclosures normally provided have been omitted since such items are disclosed in the Company's Annual Report. The Company uses the same accounting policies in preparing quarterly and annual financial statements. Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in the condensed consolidated financial statements and accompanying notes. Management bases its estimates on historical experience and on various other market-specific and relevant assumptions that management believes to be reasonable under the circumstances, the results of which form the basis for making judgements about the carrying value of assets, liabilities, and equity and the amount of revenues and expenses. Actual results could differ significantly from those estimates. The most significant estimates and assumptions that management considers in the preparation of our financial statements relate to accrued research and development costs, stock-based compensation expense and revenue recognition.

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 measures and reports certain financial instruments as assets and liabilities at fair value on a recurring basis. The following tables sets forth the fair value of the Company’s financial assets and liabilities at fair value on a recurring basis based on the three-tier fair value hierarchy (in thousands): September 30, 2022 Level 1 Level 2 Level 3 Total Financial Assets: Money market funds $ 13,554 $ — $ — $ 13,554 U.S. treasury securities 999 — — 999 Commercial paper — 35,206 — 35,206 U.S. government securities — 6,974 — 6,974 Corporate bonds — 3,974 — 3,974 Total financial assets $ 14,553 $ 46,154 $ — $ 60,707 December 31, 2021 Level 1 Level 2 Level 3 Total Financial Assets: Money market funds $ 8,888 $ — $ — $ 8,888 Commercial paper — 65,412 — 65,412 Corporate bonds — 12,574 — 12,574 Total financial assets $ 8,888 $ 77,986 $ — $ 86,874 The Company measures the fair value of money market funds on quoted prices in active markets for identical asset or liabilities. The Level 2 assets include commercial paper, U.S. government securities and corporate bonds and are valued based on quoted prices for similar assets in active markets and inputs other than quoted prices that are derived from observable market data. The Company evaluates transfers between levels at the end of each reporting period.

Cash Equivalents and Marketable

Cash Equivalents and Marketable Securities	9 Months Ended
	Sep. 30, 2022
Investments Debt And Equity Securities [Abstract]
Cash Equivalents and Marketable Securities	4. Cash Equivalents and Marketable Securities The following tables summarize the estimated fair value of the Company’s cash equivalents and marketable securities and the gross unrealized gains and losses (in thousands): September 30, 2022 Amortized Gross Gross Estimated Cash equivalents: Money market funds $ 13,554 $ — $ — $ 13,554 U.S. government securities 6,974 — — 6,974 Commercial paper 5,492 — — 5,492 Total cash equivalents 26,020 — — 26,020 Marketable securities: Commercial paper 29,809 — ( 95 ) 29,714 Corporate bonds 3,993 — ( 19 ) 3,974 U.S. treasury securities 1,001 — ( 2 ) 999 Total marketable securities $ 34,803 $ — $ ( 116 ) $ 34,687 December 31, 2021 Amortized Gross Gross Estimated Cash equivalents: Money market funds $ 8,888 $ — $ — $ 8,888 Commercial paper — — — — Total cash equivalents 8,888 — — 8,888 Marketable securities: Commercial paper 65,443 3 ( 34 ) 65,412 Corporate bonds 12,581 — ( 7 ) 12,574 Total marketable securities $ 78,024 $ 3 $ ( 41 ) $ 77,986 The following table summarizes the available-for-sale securities in an unrealized loss position for which an allowance for credit losses has not been recorded as of September 30, 2022 and December 31, 2021, aggregated by major security type and length of time in a continuous unrealized loss position: September 30, 2022 Less Than 12 Months 12 Months or Longer Total Fair Value Unrealized Fair Value Unrealized Fair Value Unrealized Commercial paper $ 30,960 $ ( 95 ) $ — $ — $ 30,960 $ ( 95 ) Corporate bonds 3,974 ( 19 ) — — 3,974 ( 19 ) U.S. treasury securities 999 ( 2 ) — — 999 ( 2 ) Total marketable securities $ 35,933 $ ( 116 ) $ — $ — $ 35,933 $ ( 116 ) December 31, 2021 Less Than 12 Months 12 Months or Longer Total Fair Value Unrealized Fair Value Unrealized Fair Value Unrealized Commercial paper $ 47,425 $ ( 34 ) $ — $ — $ 47,425 $ ( 34 ) Corporate bonds 12,573 ( 7 ) — — 12,573 ( 7 ) Total marketable securities $ 59,998 $ ( 41 ) $ — $ — $ 59,998 $ ( 41 ) The Company evaluated its securities for credit losses and considered the decline in market value to be primarily attributable to current economic and market conditions and not to a credit loss or other factors. Additionally, the Company does not intend to sell the securities in an unrealized loss position and does not expect they will be required to sell the securities before recovery of the unamortized cost basis. As of September 30, 2022 and December 31, 2021, an allowance for credit losses had no t been recognized. Given our intent and ability to hold such securities until recovery, and the lack of significant change in credit risk of these investments, we do no t consider these marketable securities to be impaired as of September 30, 2022 and December 31, 2021. There were no realized gains or losses on marketable securities for the three and nine months ended September 30, 2022 and 2021. Interest on marketable securities is included in interest income. Accrued interest receivable on available-for-sale debt securities was immaterial at September 30, 2022. Accrued interest totaled $ 0.1 million at December 31, 2021 and is excluded from the estimate of credit losses. The following table summarizes the contractual maturities of the Company’s marketable securities at estimated fair value (in thousands): September 30, December 31, 2022 2021 Due in one year or less $ 34,687 $ 77,986 Due thereafter — — Total marketable securities $ 34,687 $ 77,986 The Company may sell investments at any time for use in current operations even if they have not yet reached maturity. As a result, the Company classifies marketable securities, including securities with maturities beyond twelve months as current assets.

Accrued and Other Current Liabi

Accrued and Other Current Liabilities	9 Months Ended
	Sep. 30, 2022
Accrued Liabilities And Other Liabilities [Abstract]
Accrued and Other Current Liabilities	5. Accrued and Other Current Liabilities Accrued and other current liabilities consist of the following (in thousands): September 30, December 31, 2022 2021 Accrued compensation $ 4,690 $ 4,988 Accrued contracted research and development costs 5,842 5,995 Accrued professional and consulting fees 1,514 2,264 Other 362 783 Total accrued and other current liabilities $ 12,408 $ 14,030

Stockholders' Equity

Stockholders' Equity	9 Months Ended
	Sep. 30, 2022
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stockholders' Equity	6. Stockholders’ Equity Registered Direct Offering In May 2022, the Company issued and sold 10,752,688 shares of common stock at an offering price of $ 1.60 per share and pre-funded warrants to purchase up to 17,372,312 shares of common stock at an offering price of $ 1.5999 per warrant (representing the price per share of common stock sold in the offering minus the $ 0.0001 exercise price per warrant) in a registered direct offering pursuant to a shelf registration statement on Form S-3. The net proceeds to the Company from this offering were approximately $ 42.9 million, after deducting placement agent fees and offering costs of $ 2.1 million. Pre-Funded Warrants In February 2019, April 2020 and May 2022, the Company issued pre-funded warrants to purchase the Company’s common stock in underwritten public offerings at the offering price of the common stock, less the $ 0.0001 per share exercise price of each warrant. The warrants were recorded as a component of stockholders’ equity within additional paid-in capital and have no expiration date. Per the terms of the warrant agreements, the outstanding warrants to purchase shares of common stock may not be exercised if the holder’s ownership of the Company’s common stock would exceed 4.99 % (“Maximum Ownership Percentage”), or 9.99 % for certain holders. By written notice to the Company, each holder may increase or decrease the Maximum Ownership Percentage to any other percentage (not in excess of 19.99 % for the majority of such warrants). The revised Maximum Ownership Percentage would be effective 61 days after the notice is received by the Company . As of September 30, 2022, the following pre-funded warrants for common stock were issued and outstanding: Issue Date Expiration Date Exercise Price Number of Warrants Outstanding February 8, 2019 None $ 0.0001 3,750,000 April 30, 2020 None $ 0.0001 11,860,328 May 20, 2022 None $ 0.0001 17,120,800 Total pre-funded warrants 32,731,128 Stock-Based Compensation The 2016 Equity Incentive Plan (“2016 Plan”) provides for an automatic increase in the number of shares reserved for issuance thereunder on January 1 of each year for the remaining term of the plan (through 2028) equal to (a) 4.0 % of the number of issued and outstanding shares of common stock on December 31 of the immediately preceding year, or (b) a lesser amount as approved by the Company’s board of directors each year. As a result of this provision, on January 1, 2022 and January 1, 2021, an additional 1,974,205 and 1,918,363 shares, respectively, became available for issuance under the 2016 Plan. As of September 30, 2022 , the 2016 Plan had 1,182,245 shares available for future issuance. The following table summarizes the Company’s stock awards granted for each of the periods indicated: Three Months Ended September 30, Nine Months Ended September 30, 2022 2022 2021 2022 2021 Grants Weighted Average Grant Date Fair Value Grants Weighted Average Grant Date Fair Value Grants Weighted Average Grant Date Fair Value Grants Weighted Average Grant Date Fair Value Stock options 1,270,153 $ 0.67 396,200 $ 4.91 3,842,153 $ 2.10 2,557,600 $ 5.05 In July 2020, the Company granted 228,200 RSUs to certain employees, with vesting terms subject to regulatory, commercial, and clinical milestones, in addition to a service condition. As of September 30, 2022, 150,000 of these RSUs are outstanding. As of September 30, 2022 and 2021, respectively, the performance conditions of these RSUs were not probable of being achieved. If and when the performance milestones are deemed probable of being achieved within the required time frame, the Company may recognize up to $ 1.2 million of stock-based compensation. Under the Company’s 2016 Employee Stock Purchase Plan (“2016 ESPP”), the Company issued and sold 87,087 shares for aggregate cash proceeds of less than $ 0.1 million during the three months ended September 30, 2022 and 151,827 shares for aggregate cash proceeds of $ 0.2 million during the nine months ended September 30, 2022. There were 44,957 shares issued and sold under the 2016 ESPP for aggregate cash proceeds of $ 0.2 million during the three months ended September 30, 2021 and 82,965 shares for aggregate cash proceeds of $ 0.4 million during the nine months ended September 30, 2021. Total stock-based compensation expense related to the 2016 Plan and 2016 ESPP was as follows (in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2022 2021 2022 2021 Research and development $ 639 $ 703 $ 2,031 $ 2,057 General and administrative 926 1,404 3,653 3,887 Total stock-based compensation expense $ 1,565 $ 2,107 $ 5,684 $ 5,944 The following table summarizes the weighted-average Black-Scholes option pricing model assumptions used to estimate the fair value of stock options granted under the Company’s 2016 Plan, and the shares purchasable under the 2016 ESPP during the periods presented: Three Months Ended Nine Months Ended September 30, September 30, 2022 2021 2022 2021 2016 Plan Expected term (in years) 6.02 6.08 5.96 5.99 Expected volatility 85 % 82 % 83 % 83 % Risk-free interest 3.16 % 0.95 % 2.43 % 0.84 % Dividend yield — — — — 2016 ESPP Expected term (in years) 0.50 0.50 0.49 0.50 Expected volatility 95 % 77 % 84 % 86 % Risk-free interest 3.26 0.08 % 1.95 % 0.08 % Dividend yield — — — —

Strategic License Agreements

Strategic License Agreements	9 Months Ended
	Sep. 30, 2022
License And Collaboration Agreement [Abstract]
Strategic License Agreements	7. Strategic License Agreements On March 21, 2021 , the Company entered into an exclusive license and supply agreement with Immedica Pharma AB (“Immedica”). By entering into this agreement, the Company agreed to provide Immedica the following goods and services: i. Deliver an exclusive, sublicensable, license and know-how (the “License”) to develop and commercialize pegzilarginase (the “Product”) in the territory comprising the members states of the European Economic Area, United Kingdom, Switzerland, Andorra, Monaco, San Marino, Vatican City, Turkey, Saudi Arabia, United Arab Emirates, Qatar, Kuwait, Bahrain, and Oman (the “Territory”); ii. Complete the global pivotal PEACE (Pegzilarginase Effect on Arginase 1 Deficiency Clinical Endpoints) Phase 3 trial (“PEACE Trial”) and related Biologics License Application (“BLA”) package to file with the United States Food and Drug Administration (“FDA”), which will be leveraged by Immedica in obtaining the necessary regulatory approvals in the Territory; and iii. Perform a Pediatric Investigation Plan trial (“PIP Trial”) in order for Immedica to be able to receive certain regulatory approvals within the Territory. In addition, the Company and Immedica formed a Joint Steering Committee (“JSC”) to provide oversight to the activities performed under the agreement; however, the substance of the Company’s participation in the JSC does not represent an additional promised service, but rather, a right of the Company to protect its own interests in the arrangement. Further, the Company agreed to supply to Immedica, and Immedica agreed to purchase from the Company, substantially all commercial requirements of the Product. The terms of the agreement do not provide for either (i) an option to Immedica to purchase the Product from the Company at a discount from the standalone selling price or (ii) minimum purchase quantities. Finally, Immedica will bear (i) all costs and expenses for any development or commercialization of the Product in the Territory subject to the License exclusive of the Company’s promised goods and services summarized above and (ii) all costs and fees associated with applying for regulatory approval of the Product in the Territory. The Company received a non-refundable payment of $ 21.5 million and Immedica agreed to provide payment of 50 % of the Company’s costs incurred in performing the PIP Trial up to a maximum of $ 1.8 million. In addition, the Company has the ability to receive additional payments under the agreement of up to approximately $ 113.4 million in regulatory and commercial milestone payments, assuming an exchange rate of $ 0.98 to € 1.00 . The Company is also entitled to receive royalties in the mid-20 percent range on net sales of the Product in the Territory. In July 2021, the Company modified the agreement with Immedica to provide certain additional services in relation to the PEACE Trial and BLA package performance obligation in exchange for the reimbursement of up to $ 3.0 million of the actual costs incurred in relation to such incremental services. The Company concluded that Immedica meets the definition to be accounted for as a customer because the Company is delivering intellectual property and other services within the Company’s normal course of business, in which the parties are not jointly sharing the risks and rewards. Therefore, the Company concluded that the promises summarized above represent transactions with a customer within the scope of ASC 606. The Company determined that the following promises represent distinct promised services, and therefore, performance obligations: (i) the License, (ii) the PEACE Trial and BLA package, and (iii) the PIP Trial. Specifically, in making these determinations, the Company considered the following factors: - As of inception of the agreement, the Company had completed the Phase 1/2 clinical trial related to the Product and were conducting the ongoing PEACE Trial. Accordingly, the Company is not promising, nor expecting, to perform additional research and development activities pursuant to the agreement that would either significantly modify, customize or be considered highly interdependent or interrelated with pegzilarginase. - The License represents functional intellectual property given the functionality of the License is not expected to change substantially as a result of the company’s ongoing activities. - The services necessary to complete the PEACE Trial, BLA package and PIP Trial could be performed by other parties. Given that Immedica is not obligated to purchase any minimum amount or quantities of Product, the supply of Product for commercial use to Immedica was determined to be an option for Immedica, rather than a performance obligation of the Company at contract inception and will be accounted for if and when exercised. The Company also determined that Immedica’s option to purchase the Product does not create a material right as the expected pricing is not at a discount. The Company determined that the upfront fixed payment amount of $ 21.5 million must be included in the transaction price. Additionally, the Company determined at inception of the arrangement that 50 % of the probable estimated costs to be incurred in relation to the PIP Trial exceeded $ 1.8 million and included the full reimbursement amount of $1.8 million in the transaction price. Upon subsequent re-evaluation due to changing facts and circumstances, the Company determined the probable estimated costs are now less than the maximum allowable reimbursement and a portion of the variable consideration was constrained, which did not materially impact the revenue recognized to date. Additionally, upon the modification of the agreement in July 2021, the Company determined that the probable estimated costs to perform the additional services related to the PEACE Trial and BLA package exceeds the maximum allowable reimbursement of $ 3.0 million. Therefore, the Company included an estimated total of $ 3.6 million that will be due in relation to the PIP Trial, PEACE Trial, and BLA package in the transaction price and it is probable that a significant reversal will not occur in the future. In total, the modified transaction price was determined to be $ 25.1 million. The Company has allocated $ 9.6 million and $ 3.5 million of the modified transaction price to the PEACE Trial and BLA package and PIP Trial performance obligations, respectively, based on the stand-alone selling prices ("SSP"), which was based on the estimated costs that a third-party would charge in performing such services on a stand-alone basis. The SSP for the License was established at inception of the arrangement using a residual value approach due to the uniqueness of and lack of observable data related to the License, and without a specific analog from which to make reliable estimates, resulting in an allocation of $ 12.0 million. The potential regulatory milestone payments that the Company is eligible to receive were excluded from the transaction price, as the milestone amounts were fully constrained based on the probability of achievement, since the milestones relate to successful achievement of certain regulatory approvals, which might not be achieved. The Company determined that the royalties and commercial milestone payments relate predominantly to the license of intellectual property and are therefore excluded from the transaction price under the sales- or usage-based royalty exception of Topic 606. The Company will reevaluate the transaction price, including all constrained amounts, at the end of each reporting period and as uncertain events are resolved or other changes in circumstances occur, the Company will adjust its estimate of the transaction price as necessary. The Company will recognize the royalties and commercial milestone payments as revenue when the associated sales occur, and relevant sales-based thresholds are met. The Company assessed the arrangement with Immedica and concluded that a significant financing component does not exist. The Company recognized revenue allocated to the License performance obligation at a point in time and upon transfer of the License. The Company completed the transfer of the know-how necessary for Immedica to benefit from the License in June 2021 and recognized $ 12.0 million of revenue at that time. The development fee allocated to the PEACE Trial, BLA package and PIP Trial performance obligations is recognized over time using an input method of costs incurred related to the performance obligations. For the three and nine months ended September 30, 2022, the Company recognized revenue of $ 0.2 million and $ 2.2 million, under the Immedica Agreement related to the progress in the PEACE Trial and BLA package performance. For the three and nine months ended September 30, 2021, the Company recognized revenue of $ 1.4 million and $ 3.1 million, respectively, related to the PEACE Trial and BLA package performance obligation. For the three and nine months ended September 30, 2021, the Company recognized no revenue and $ 12.0 million, respectively, related to the transfer of the License. As of September 30, 2022 , and 2021, the Company has recorded deferred revenue of $ 2.7 million and $ 6.4 million, respectively, associated with the license and supply agreement with Immedica, of which $ 0.5 million and $ 4.8 million, respectively, is classified as current. Contract Balances from Customer Contract The timing of revenue recognition, billings and cash collections results in contract assets and contract liabilities on the balance sheets. The Company recognizes license and development receivables based on billed services, which are derecognized upon reimbursement. When consideration is received, or such consideration is unconditionally due, from a customer prior to transferring goods or services to the customer under the terms of a contract, a contract liability is recorded. Contract liabilities are recognized as revenue after control of the goods or services is transferred to the customer and all revenue recognition criteria have been met. The following table presents changes in the Company’s contract liabilities for the periods presented (in thousands): December 31, September 30, Nine Months Ended September 30, 2022 2021 Additions Deductions 2022 Contract liabilities: Deferred revenue $ 3,576 $ 1,264 $ ( 2,161 ) $ 2,679 The Company had no contract liabilities during the nine months ended September 30, 2021 and no contract assets during the nine months ended September 30, 2022 and 2021 .

Net Loss Per Share

Net Loss Per Share	9 Months Ended
	Sep. 30, 2022
Earnings Per Share [Abstract]
Net Loss Per Share	8. Net Loss Per Share Basic and diluted net loss per share is computed by dividing net loss by the weighted-average number of common stock and pre-funded warrants outstanding during the period. The pre-funded warrants are included in the computation of basic net loss per share as the exercise price is negligible and they are fully vested and exercisable. For periods in which the Company generated a net loss, the Company does not include the potential impact of dilutive securities in diluted net loss per share, as the impact of these items is anti-dilutive. The following weighted-average equity instruments were excluded from the calculation of diluted net loss per share because their effect would have been anti-dilutive for the periods presented: Three Months Ended Nine Months Ended September 30, September 30, 2022 2021 2022 2021 Options to purchase common stock 8,788,325 7,066,486 8,384,866 6,650,758 Unvested restricted stock units 150,000 194,435 182,879 202,540

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2022
Accounting Policies [Abstract]
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in the condensed consolidated financial statements and accompanying notes. Management bases its estimates on historical experience and on various other market-specific and relevant assumptions that management believes to be reasonable under the circumstances, the results of which form the basis for making judgements about the carrying value of assets, liabilities, and equity and the amount of revenues and expenses. Actual results could differ significantly from those estimates. The most significant estimates and assumptions that management considers in the preparation of our financial statements relate to accrued research and development costs, stock-based compensation expense and revenue recognition.

Fair Value Measurement (Tables)

Fair Value Measurement (Tables)	9 Months Ended
	Sep. 30, 2022
Fair Value Disclosures [Abstract]
Financial Assets and Liabilities Measured at Fair Value on Recurring Basis	The following tables sets forth the fair value of the Company’s financial assets and liabilities at fair value on a recurring basis based on the three-tier fair value hierarchy (in thousands): September 30, 2022 Level 1 Level 2 Level 3 Total Financial Assets: Money market funds $ 13,554 $ — $ — $ 13,554 U.S. treasury securities 999 — — 999 Commercial paper — 35,206 — 35,206 U.S. government securities — 6,974 — 6,974 Corporate bonds — 3,974 — 3,974 Total financial assets $ 14,553 $ 46,154 $ — $ 60,707 December 31, 2021 Level 1 Level 2 Level 3 Total Financial Assets: Money market funds $ 8,888 $ — $ — $ 8,888 Commercial paper — 65,412 — 65,412 Corporate bonds — 12,574 — 12,574 Total financial assets $ 8,888 $ 77,986 $ — $ 86,874

Cash Equivalents and Marketab_2

Cash Equivalents and Marketable Securities (Tables)	9 Months Ended
	Sep. 30, 2022
Investments Debt And Equity Securities [Abstract]
Schedule of Estimated Fair Value of Cash Equivalents and Marketable Securities	The following tables summarize the estimated fair value of the Company’s cash equivalents and marketable securities and the gross unrealized gains and losses (in thousands): September 30, 2022 Amortized Gross Gross Estimated Cash equivalents: Money market funds $ 13,554 $ — $ — $ 13,554 U.S. government securities 6,974 — — 6,974 Commercial paper 5,492 — — 5,492 Total cash equivalents 26,020 — — 26,020 Marketable securities: Commercial paper 29,809 — ( 95 ) 29,714 Corporate bonds 3,993 — ( 19 ) 3,974 U.S. treasury securities 1,001 — ( 2 ) 999 Total marketable securities $ 34,803 $ — $ ( 116 ) $ 34,687 December 31, 2021 Amortized Gross Gross Estimated Cash equivalents: Money market funds $ 8,888 $ — $ — $ 8,888 Commercial paper — — — — Total cash equivalents 8,888 — — 8,888 Marketable securities: Commercial paper 65,443 3 ( 34 ) 65,412 Corporate bonds 12,581 — ( 7 ) 12,574 Total marketable securities $ 78,024 $ 3 $ ( 41 ) $ 77,986
Schedule of Gross Unrealized Losses and Fair Value by Investment Category and Age	The following table summarizes the available-for-sale securities in an unrealized loss position for which an allowance for credit losses has not been recorded as of September 30, 2022 and December 31, 2021, aggregated by major security type and length of time in a continuous unrealized loss position: September 30, 2022 Less Than 12 Months 12 Months or Longer Total Fair Value Unrealized Fair Value Unrealized Fair Value Unrealized Commercial paper $ 30,960 $ ( 95 ) $ — $ — $ 30,960 $ ( 95 ) Corporate bonds 3,974 ( 19 ) — — 3,974 ( 19 ) U.S. treasury securities 999 ( 2 ) — — 999 ( 2 ) Total marketable securities $ 35,933 $ ( 116 ) $ — $ — $ 35,933 $ ( 116 ) December 31, 2021 Less Than 12 Months 12 Months or Longer Total Fair Value Unrealized Fair Value Unrealized Fair Value Unrealized Commercial paper $ 47,425 $ ( 34 ) $ — $ — $ 47,425 $ ( 34 ) Corporate bonds 12,573 ( 7 ) — — 12,573 ( 7 ) Total marketable securities $ 59,998 $ ( 41 ) $ — $ — $ 59,998 $ ( 41 )
Summary of Contractual Maturities of Marketable Securities at Estimated Fair Value	The following table summarizes the contractual maturities of the Company’s marketable securities at estimated fair value (in thousands): September 30, December 31, 2022 2021 Due in one year or less $ 34,687 $ 77,986 Due thereafter — — Total marketable securities $ 34,687 $ 77,986

Accrued and Other Current Lia_2

Accrued and Other Current Liabilities (Tables)	9 Months Ended
	Sep. 30, 2022
Accrued Liabilities And Other Liabilities [Abstract]
Accrued and Other Current Liabilities	Accrued and other current liabilities consist of the following (in thousands): September 30, December 31, 2022 2021 Accrued compensation $ 4,690 $ 4,988 Accrued contracted research and development costs 5,842 5,995 Accrued professional and consulting fees 1,514 2,264 Other 362 783 Total accrued and other current liabilities $ 12,408 $ 14,030

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	9 Months Ended
	Sep. 30, 2022
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Pre-funded Warrants for Common Stock Issued and Outstanding	As of September 30, 2022, the following pre-funded warrants for common stock were issued and outstanding: Issue Date Expiration Date Exercise Price Number of Warrants Outstanding February 8, 2019 None $ 0.0001 3,750,000 April 30, 2020 None $ 0.0001 11,860,328 May 20, 2022 None $ 0.0001 17,120,800 Total pre-funded warrants 32,731,128
Schedule of Company's Stock Awards Granted	The following table summarizes the Company’s stock awards granted for each of the periods indicated: Three Months Ended September 30, Nine Months Ended September 30, 2022 2022 2021 2022 2021 Grants Weighted Average Grant Date Fair Value Grants Weighted Average Grant Date Fair Value Grants Weighted Average Grant Date Fair Value Grants Weighted Average Grant Date Fair Value Stock options 1,270,153 $ 0.67 396,200 $ 4.91 3,842,153 $ 2.10 2,557,600 $ 5.05
Summary of Stock-Based Compensation Expense	Total stock-based compensation expense related to the 2016 Plan and 2016 ESPP was as follows (in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2022 2021 2022 2021 Research and development $ 639 $ 703 $ 2,031 $ 2,057 General and administrative 926 1,404 3,653 3,887 Total stock-based compensation expense $ 1,565 $ 2,107 $ 5,684 $ 5,944
Schedule of Estimated Fair Value of Stock Options Granted	The following table summarizes the weighted-average Black-Scholes option pricing model assumptions used to estimate the fair value of stock options granted under the Company’s 2016 Plan, and the shares purchasable under the 2016 ESPP during the periods presented: Three Months Ended Nine Months Ended September 30, September 30, 2022 2021 2022 2021 2016 Plan Expected term (in years) 6.02 6.08 5.96 5.99 Expected volatility 85 % 82 % 83 % 83 % Risk-free interest 3.16 % 0.95 % 2.43 % 0.84 % Dividend yield — — — — 2016 ESPP Expected term (in years) 0.50 0.50 0.49 0.50 Expected volatility 95 % 77 % 84 % 86 % Risk-free interest 3.26 0.08 % 1.95 % 0.08 % Dividend yield — — — —

Strategic License Agreements (T

Strategic License Agreements (Tables)	9 Months Ended
	Sep. 30, 2022
License And Collaboration Agreement [Abstract]
Summary of Changes in Contract Liabilities	The following table presents changes in the Company’s contract liabilities for the periods presented (in thousands): December 31, September 30, Nine Months Ended September 30, 2022 2021 Additions Deductions 2022 Contract liabilities: Deferred revenue $ 3,576 $ 1,264 $ ( 2,161 ) $ 2,679

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	9 Months Ended
	Sep. 30, 2022
Earnings Per Share [Abstract]
Weighted-Average Equity Instruments Excluded from Calculation of Diluted Net Loss Per Share	The following weighted-average equity instruments were excluded from the calculation of diluted net loss per share because their effect would have been anti-dilutive for the periods presented: Three Months Ended Nine Months Ended September 30, September 30, 2022 2021 2022 2021 Options to purchase common stock 8,788,325 7,066,486 8,384,866 6,650,758 Unvested restricted stock units 150,000 194,435 182,879 202,540

The Company and Basis of Pres_2

The Company and Basis of Presentation - Additional Information (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2022 USD ($) Segment	Dec. 31, 2021 USD ($)
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Number of operating segments | Segment	1
Working capital	$ 64,500
Accumulated deficit	(406,802)	$ (341,809)
Cash, cash equivalents, marketable securities, and restricted cash	$ 75,200

Fair Value Measurements - Finan

Fair Value Measurements - Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Financial Assets:
Financial assets, fair value	$ 60,707	$ 86,874
Corporate bonds
Financial Assets:
Financial assets, fair value	3,974	12,574
Commercial paper
Financial Assets:
Financial assets, fair value	35,206	65,412
Level 1
Financial Assets:
Financial assets, fair value	14,553	8,888
Level 2
Financial Assets:
Financial assets, fair value	46,154	77,986
Level 2 | Corporate bonds
Financial Assets:
Financial assets, fair value	3,974	12,574
Level 2 | Commercial paper
Financial Assets:
Financial assets, fair value	35,206	65,412
Money market funds
Financial Assets:
Financial assets, fair value	13,554	8,888
Money market funds | Level 1
Financial Assets:
Financial assets, fair value	13,554	$ 8,888
U.S. treasury securities
Financial Assets:
Financial assets, fair value	999
U.S. treasury securities | Level 1
Financial Assets:
Financial assets, fair value	999
U.S. Government Securities
Financial Assets:
Financial assets, fair value	6,974
U.S. Government Securities | Level 2
Financial Assets:
Financial assets, fair value	$ 6,974

Cash Equivalents and Marketab_3

Cash Equivalents and Marketable Securities - Schedule of Estimated Fair Value of Cash Equivalents and Marketable Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Schedule Of Available For Sale Securities [Line Items]
Cash equivalents, amortized cost	$ 26,020	$ 8,888
Cash equivalents, gross unrealized losses	0	0
Cash equivalents, estimated fair value	26,020	8,888
Marketable securities, amortized cost	34,803	78,024
Marketable securities, gross unrealized gains		3
Marketable securities, gross unrealized losses	(116)	(41)
Marketable securities, estimated fair value	34,687	77,986
Money market funds
Schedule Of Available For Sale Securities [Line Items]
Cash equivalents, amortized cost	13,554	8,888
Cash equivalents, gross unrealized losses		0
Cash equivalents, estimated fair value	13,554	8,888
U.S. Government Securities
Schedule Of Available For Sale Securities [Line Items]
Cash equivalents, amortized cost	6,974
Cash equivalents, estimated fair value	6,974
Commercial paper
Schedule Of Available For Sale Securities [Line Items]
Cash equivalents, amortized cost	5,492	0
Cash equivalents, gross unrealized losses	0	0
Cash equivalents, estimated fair value	5,492	0
Marketable securities, amortized cost	29,809	65,443
Marketable securities, gross unrealized gains		3
Marketable securities, gross unrealized losses	(95)	(34)
Marketable securities, estimated fair value	29,714	65,412
Corporate bonds
Schedule Of Available For Sale Securities [Line Items]
Marketable securities, amortized cost	3,993	12,581
Marketable securities, gross unrealized losses	(19)	(7)
Marketable securities, estimated fair value	3,974	$ 12,574
U.S. treasury securities
Schedule Of Available For Sale Securities [Line Items]
Marketable securities, amortized cost	1,001
Marketable securities, gross unrealized losses	(2)
Marketable securities, estimated fair value	$ 999

Cash Equivalents and Marketab_4

Cash Equivalents and Marketable Securities - Schedule of Gross Unrealized Losses and Fair Value by Investment Category and Age (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Schedule Of Available For Sale Securities [Line Items]
Less than 12 Months, Fair Value	$ 35,933	$ 59,998
Less than 12 Months, Unrealized Loss	(116)	(41)
Total, Fair Value	35,933	59,998
Total, Unrealized Loss	(116)	(41)
U.S. treasury securities
Schedule Of Available For Sale Securities [Line Items]
Less than 12 Months, Fair Value	999
Less than 12 Months, Unrealized Loss	(2)
Total, Fair Value	999
Total, Unrealized Loss	(2)
Commercial paper
Schedule Of Available For Sale Securities [Line Items]
Less than 12 Months, Fair Value	30,960	47,425
Less than 12 Months, Unrealized Loss	(95)	(34)
Total, Fair Value	30,960	47,425
Total, Unrealized Loss	(95)	(34)
Corporate bonds
Schedule Of Available For Sale Securities [Line Items]
Less than 12 Months, Fair Value	3,974	12,573
Less than 12 Months, Unrealized Loss	(19)	(7)
Total, Fair Value	3,974	12,573
Total, Unrealized Loss	$ (19)	$ (7)

Cash Equivalents and Marketab_5

Cash Equivalents and Marketable Securities - Additional Information (Details) - US Government Agencies Debt Securities - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Cash Equivalents And Marketable Securities [Line Items]
Allowance for Credit Loss	$ 0		$ 0		$ 0
Impairment of marketable securities			0		0
Realized gains or losses on marketable securities	$ 0	$ 0	$ 0	$ 0
Accrued interest receivable on available-for-sale debt securities					$ 100

Cash Equivalents and Marketab_6

Cash Equivalents and Marketable Securities - Summary of Contractual Maturities of Marketable Securities at Estimated Fair Value (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Investments Debt And Equity Securities [Abstract]
Due in one year or less	$ 34,687	$ 77,986
Total marketable securities	$ 34,687	$ 77,986

Accrued and Other Current Lia_3

Accrued and Other Current Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Accrued Liabilities And Other Liabilities [Abstract]
Accrued compensation	$ 4,690	$ 4,988
Accrued contracted research and development costs	5,842	5,995
Accrued professional and consulting fees	1,514	2,264
Other	362	783
Total accrued and other current liabilities	$ 12,408	$ 14,030

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions		1 Months Ended		3 Months Ended		9 Months Ended
	Jan. 01, 2022	May 31, 2022	Jul. 31, 2020	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Jan. 01, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of warrants sold		17,372,312
Offering price of warrant		$ 1.5999
Exercise price per warrant		$ 0.0001
proceeds from issuance of common stock and pre-funded warrants		$ 42.9
Placement agent fees and offering costs		$ 2.1
Maximum ownership percentage of common stock shares for outstanding warrants to be exercised						4.99%
Period after notice received by company maximum ownership percentage to be effective description						The revised Maximum Ownership Percentage would be effective 61 days after the notice is received by the Company
Maximum ownership percentage of common stock shares for outstanding warrants to be exercised for certain holders						9.99%
2016 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Maximum annual percentage increase	4%
Additional number of shares available for issuance	1,974,205							1,918,363
Common stock available for future issuance				1,182,245		1,182,245
2016 Equity Incentive Plan | Restricted Stock Units RSU
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares, granted to employees			228,200
RSUs outstanding				150,000		150,000
Total stock-based compensation expense						$ 1.2
2016 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock option to purchase an aggregate of common stock shares				87,087	44,957	151,827	82,965
Aggregate cash proceeds from sale of shares					$ 0.2	$ 0.2	$ 0.4
Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Maximum ownership percentage of common stock shares for outstanding warrants to be exercised						19.99%
Maximum [Member] | 2016 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Aggregate cash proceeds from sale of shares				$ 0.1
Common Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of common stock shares issued		10,752,688
Common stock offering price		$ 1.60

Stockholders' Equity - Summary

Stockholders' Equity - Summary of Pre-funded Warrants for Common Stock Issued and Outstanding (Details) - $ / shares	9 Months Ended
	Sep. 30, 2022	May 31, 2022
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Exercise Price		$ 0.0001
Pre-funded Warrants
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Warrants Outstanding	32,731,128
Pre-funded Warrants | February 8, 2019
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Issue Date	Feb. 08, 2019
Expiration Date	None
Exercise Price	$ 0.0001
Number of Warrants Outstanding	3,750,000
Pre-funded Warrants | April 30, 2020
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Issue Date	Apr. 30, 2020
Expiration Date	None
Exercise Price	$ 0.0001
Number of Warrants Outstanding	11,860,328
Pre-funded Warrants | May 20, 2022
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Issue Date	May 20, 2022
Expiration Date	None
Exercise Price	$ 0.0001
Number of Warrants Outstanding	17,120,800

Stockholders' Equity - Schedule

Stockholders' Equity - Schedule of Company's Stock Awards Granted (Details) - 2016 Equity Incentive Plan - Stock Options - $ / shares	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]
Grants	1,270,153	396,200	3,842,153	2,557,600
Weighted Average Grant Date Fair Value	$ 0.67	$ 4.91	$ 2.10	$ 5.05

Stockholders' Equity - Summar_2

Stockholders' Equity - Summary of Stock-Based Compensation Expense (Details) - 2016 Equity Incentive Plans and Employee Stock Purchase Plan - 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]
Total stock-based compensation expense	$ 1,565	$ 2,107	$ 5,684	$ 5,944
Research and Development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	639	703	2,031	2,057
General and Administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 926	$ 1,404	$ 3,653	$ 3,887

Stockholders' Equity - Schedu_2

Stockholders' Equity - Schedule of Estimate Fair Value of Stock Options Granted (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
2016 Equity Incentive Plan
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Expected term (in years)	6 years 7 days	6 years 29 days	5 years 11 months 15 days	5 years 11 months 26 days
Expected volatility	85%	82%	83%	83%
Risk-free interest	3.16%	0.95%	2.43%	0.84%
Dividend yield	0%	0%	0%	0%
2016 Employee Stock Purchase Plan
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Expected term (in years)	6 months	6 months	5 months 26 days	6 months
Expected volatility	95%	77%	84%	86%
Risk-free interest	3.26%	0.08%	1.95%	0.08%
Dividend yield	0%	0%	0%	0%

Strategic License Agreements -

Strategic License Agreements - Additional Information (Details)	1 Months Ended		3 Months Ended			9 Months Ended
	Jul. 31, 2021 USD ($)	Jun. 30, 2021 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)	Mar. 31, 2021 USD ($) € / shares $ / shares	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)	Dec. 31, 2021 USD ($)
Research And Development Arrangement Contract To Perform For Others [Line Items]
Revenue recognized			$ 174,000	$ 1,399,000		$ 2,161,000	$ 15,095,000
Current deferred revenue			505,000			505,000		$ 2,359,000
Contract liabilities			2,679,000	0		2,679,000	0	$ 3,576,000
Contract assets			0	0		$ 0	0
Immedica Pharma AB
Research And Development Arrangement Contract To Perform For Others [Line Items]
Research agreement date						2021-03
Non refundable payment received					$ 21,500,000
Percentage of payment for cost incurred in PIP trial					50%
Additional upfront payment to be received					$ 113,400,000
Rate of revenue share					25%
Reimbursement	$ 3,000,000
Upfront payment					$ 21,500,000
Modified transaction price	25,100,000
Estimated amount incurred	$ 3,600,000
Allocation price net					12,000,000
Total deferred revenue			2,700,000	6,400,000		$ 2,700,000	6,400,000
Current deferred revenue			500,000	4,800,000		500,000	4,800,000
Immedica Pharma AB | PEACE Trial and BLA Package
Research And Development Arrangement Contract To Perform For Others [Line Items]
Allocated amount of transaction price					9,600,000
Revenue recognized			$ 200,000	1,400,000		$ 2,200,000	3,100,000
Immedica Pharma AB | PIP Trial
Research And Development Arrangement Contract To Perform For Others [Line Items]
Allocated amount of transaction price					$ 3,500,000
Immedica Pharma AB | License Agreements
Research And Development Arrangement Contract To Perform For Others [Line Items]
Revenue recognized		$ 12,000,000		$ 0			$ 12,000,000
Immedica Pharma AB | Maximum
Research And Development Arrangement Contract To Perform For Others [Line Items]
Percentage of payment for cost incurred in PIP trial					50%
Costs incurred in performing PIP the trial					$ 1,800,000
Milestone payments exchange rate | € / shares					1
Immedica Pharma AB | Minimum
Research And Development Arrangement Contract To Perform For Others [Line Items]
Milestone payments exchange rate | $ / shares					0.98

Strategic License Agreements _2

Strategic License Agreements - Summary of Changes in Contract Liabilities (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2022 USD ($)
Change in Contract with Customer, Liability [Abstract]
Beginning Balance	$ 3,576
Additions	1,264
Deductions	(2,161)
Ending Balance	$ 2,679

Net Loss Per Share - Weighted-A

Net Loss Per Share - Weighted-Average Equity Instruments Excluded from Calculation of Diluted Net Loss Per Share (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Restricted Common Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share	150,000	194,435	182,879	202,540
Options to Purchase Common Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share	8,788,325	7,066,486	8,384,866	6,650,758