Molecular Templates (MTEM) 10-Q 10 Nov 22 2022 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2022	Nov. 07, 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	MTEM
Entity Registrant Name	Molecular Templates, Inc.
Entity Central Index Key	0001183765
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity File Number	001-32979
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	94-3409596
Entity Address, Address Line One	9301 Amberglen Blvd
Entity Address, Address Line Two	Suite 100
Entity Address, City or Town	Austin
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	78729
City Area Code	512
Local Phone Number	869-1555
Entity Common Stock, Shares Outstanding		56,351,647
Title of 12(b) Security	Common Stock, $0.001 Par Value Per Share
Security Exchange Name	NASDAQ
Document Quarterly Report	true
Document Transition Report	false

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 22,277	$ 24,983
Marketable securities, current	57,168	118,061
Prepaid expenses	3,729	3,917
Other current assets	4,011	1,254
Total current assets	87,185	148,215
Marketable securities, non-current	0	8,986
Operating lease right-of-use assets	11,120	8,608
Property and equipment, net	16,347	19,309
Other assets	3,994	7,244
Total assets	118,646	192,362
Current liabilities:
Accounts payable	1,085	1,612
Accrued liabilities	8,890	9,515
Deferred revenue, current	38,290	32,937
Other current liabilities	1,957	2,606
Total current liabilities	50,222	46,670
Deferred revenue, long-term	14,641	33,350
Long-term debt, net of current portion	35,940	35,491
Operating lease liabilities	12,422	9,564
Other liabilities	1,269	1,625
Total liabilities	114,494	126,700
Commitments and contingencies (Note 10)	0	0
Stockholders’ equity
Preferred stock, $0.001 par value: Authorized: 2,000,000 shares at June 30, 2022 and December 31, 2021; issued and outstanding: 250 shares at June 30, 2022 and December 31, 2021	0	0
Common stock, $0.001 par value: Authorized: 150,000,000 shares at September 30, 2022 and December 31, 2021; issued and outstanding: 56,351,647 shares at September 30, 2022 and 56,305,049 shares at December 31, 2021	56	56
Additional paid-in capital	427,042	417,704
Accumulated other comprehensive loss	(227)	(48)
Accumulated deficit	(422,719)	(352,050)
Total stockholders’ equity	4,152	65,662
Total liabilities and stockholders’ equity	$ 118,646	$ 192,362

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2022	Dec. 31, 2021
Statement Of Financial Position [Abstract]
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	2,000,000	2,000,000
Preferred stock, shares issued	250	250
Preferred stock, shares outstanding	250	250
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	150,000,000	150,000,000
Common stock, shares issued	56,351,647	56,305,049
Common stock, shares outstanding	56,351,647	56,305,049

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
Total revenue	$ 4,240	$ 2,379	$ 17,143	$ 20,733
Operating expenses:
Research and development	21,973	22,881	64,835	65,328
General and administrative	5,934	9,027	20,120	26,178
Total operating expenses	27,907	31,908	84,955	91,506
Loss from operations	23,667	29,529	67,812	70,773
Interest and other income, net	307	175	563	308
Interest and other expense, net	(1,252)	(1,033)	(3,394)	(2,301)
Net loss	24,612	30,387	70,643	72,766
Provision for income taxes	26	0	26	0
Net loss attributable to common shareholders	$ 24,638	$ 30,387	$ 70,669	$ 72,766
Net loss per share attributable to common shareholders:
Basic	$ 0.44	$ 0.54	$ 1.25	$ 1.32
Diluted	$ 0.44	$ 0.54	$ 1.25	$ 1.32
Weighted average number of shares used in net loss per share calculations:
Basic	56,350,858	56,174,644	56,328,664	54,958,365
Diluted	56,350,858	56,174,644	56,328,664	54,958,365
Research And Development Revenue, Related Party
Total revenue	$ 0	$ 0	$ 0	$ 13,136
Research And Development Revenue, Other
Total revenue	$ 4,240	$ 2,379	$ 17,143	$ 7,597

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	$ 24,638	$ 30,387	$ 70,669	$ 72,766
Other comprehensive income:
Unrealized gain/(loss) on available-for-sale securities	103	(9)	(179)	(18)
Comprehensive loss	$ 24,535	$ 30,396	$ 70,848	$ 72,784

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Preferred Stock	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income, Gain/(Loss)	Accumulated Deficit
Beginning balance at Dec. 31, 2020	$ 59,340	$ 0	$ 50	$ 328,314	$ 17	$ (269,041)
Issuance of common stock pursuant to stock plans				1,582
Stock-based compensation				12,822
Other comprehensive income, gain/(loss)					(18)
Issuance of common stock pursuant to public offering			6	71,139
Net loss	(72,766)					(72,766)
Ending balance at Sep. 30, 2021	72,105	0	56	413,857	(1)	(341,807)
Beginning balance at Jun. 30, 2021	97,402	0	56	408,758	8	(311,420)
Issuance of common stock pursuant to stock plans				856
Stock-based compensation				4,243
Other comprehensive income, gain/(loss)					(9)
Issuance of common stock pursuant to public offering			0	0
Net loss						(30,387)
Ending balance at Sep. 30, 2021	72,105	0	56	413,857	(1)	(341,807)
Beginning balance at Dec. 31, 2021	65,662	0	56	417,704	(48)	(352,050)
Issuance of common stock pursuant to stock plans				33
Stock-based compensation				9,305
Other comprehensive income, gain/(loss)					(179)
Issuance of common stock pursuant to public offering			0	0
Net loss	(70,669)					(70,669)
Ending balance at Sep. 30, 2022	4,152	0	56	427,042	(227)	(422,719)
Beginning balance at Jun. 30, 2022	26,037	0	56	424,392	(330)	(398,081)
Issuance of common stock pursuant to stock plans				9
Stock-based compensation				2,641
Other comprehensive income, gain/(loss)					103
Issuance of common stock pursuant to public offering			0	0
Net loss						(24,638)
Ending balance at Sep. 30, 2022	$ 4,152	$ 0	$ 56	$ 427,042	$ (227)	$ (422,719)

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	$ 70,669	$ 72,766
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation, amortization and other	5,564	4,828
Stock-based compensation expense	9,305	12,822
Interest accrued on long-term debt	64	137
Amortization of debt discount and accretion related to debt	747	497
Accretion of asset retirement obligations	98	100
Loss on disposal of property and equipment	29	356
Changes in operating assets and liabilities:
Prepaid expenses	188	(1,543)
Accounts receivable, related party	0	234
Other assets	(724)	818
Operating lease right-of-use assets and liabilities	(572)	504
Accounts payable	(572)	(1,048)
Accrued liabilities	(694)	(1,635)
Other liabilities	0	(472)
Other liabilities, related party	0	(11,853)
Deferred revenue	(13,356)	64,990
Deferred revenue, related party	0	(3,895)
Net cash used in operating activities	(70,592)	(7,926)
Cash flows from investing activities:
Purchases of property and equipment	(2,886)	(3,113)
Purchase of marketable securities	(52,132)	(184,490)
Sales of marketable securities	121,990	105,350
Net cash (used in)/provided by investing activities	66,972	(82,253)
Cash flows from financing activities:
Payments of capital and finance lease obligations	0	(1)
Proceeds from issuance of long-term debt	0	19,828
Proceeds from stock option exercises	33	1,582
Proceeds from issuance of common stock and warrants, net offering expenses	0	71,145
Fees paid on loan modification	(298)	0
Net cash (used in)/provided by financing activities	(265)	92,554
Net (decrease)/increase in cash, cash equivalents, and restricted cash	(3,885)	2,375
Cash, cash equivalents and restricted cash, beginning of period	28,651	28,886
Cash, cash equivalents and restricted cash, end of period	24,766	31,261
Reconciliation of cash, cash equivalents and restricted cash
Cash and cash equivalents	22,277	27,593
Restricted cash included in other assets	$ 2,489	$ 3,668
Restricted Cash and Cash Equivalents, Noncurrent, Statement of Financial Position [Extensible Enumeration]	Other assets	Other assets
Total cash, cash equivalents and restricted cash	$ 24,766	$ 31,261
Supplemental Cash Flow Information
Cash paid for interest	2,471	1,481
Non-Cash Investing and Financing Activities
Fixed asset additions in accounts payable and accrued expenses	$ 50	$ 237

Organization and Summary of Sig

Organization and Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2022
Accounting Policies [Abstract]
Organization and Summary of Significant Accounting Policies	NOTE 1 — ORGANIZATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Nature of the Business Molecular Templates, Inc. (the “Company”) is a clinical stage biopharmaceutical company formed in 2001, with a biologic therapeutic platform for the development of novel targeted therapeutics for cancer and other serious diseases, headquartered in Austin, Texas. The Company’s focus is on the research and development of therapeutic compounds for a variety of cancers. The Company operates its business as a single segment, as defined by U.S. generally accepted accounting principles (“U.S. GAAP”). Basis of Presentation The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America and include the accounts of the Company and its wholly owned subsidiary and reflect the elimination of intercompany accounts and transactions. The preparation of condensed consolidated financial statements requires management to make estimates and assumptions that affect the recorded amounts reported therein. A change in facts or circumstances surrounding the estimates could result in a change to estimates and impact future operating results. Certain accounts in the prior financial statements have been reclassified for comparative purposes to conform to the presentation in the current financial statements. These reclassifications have no material effect on previously reported financials. The unaudited condensed consolidated financial statements and related disclosures have been prepared with the presumption that users of the interim unaudited condensed consolidated financial statements have read or have access to the audited consolidated financial statements for the preceding fiscal year. Accordingly, these unaudited condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto for the year ended December 31, 2021 included in the Company’s Annual Report on Form 10-K filed with the SEC on March 29, 2022. Going Concern The Company has adopted as required the Financial Accounting Standards Board (FASB) Accounting Standards Codification (ASC) Topic 205-40, Presentation of Financial Statements - Going Concern, which requires that management contemplate the realization of assets and liquidation of liabilities in the normal course of business, and evaluate whether there are relevant conditions and events that in aggregate raise substantial doubt about the entity’s ability to continue as a going concern and to meet its obligations as they become due within one year after the date that the financial statements are issued. Under this standard, management’s assessment shall not take into consideration the potential mitigating effects of management’s plans that have not been fully implemented as of the date the financial statements are issued. The Company has not yet established an ongoing source of revenues sufficient to cover its operating costs and to provide sufficient certainty that it will continue as a going concern. As of September 30, 2022, the Company had an accumulated deficit of $422.7 million. The ability of the Company to continue as a going concern is dependent on the Company obtaining adequate capital to fund operating losses until it becomes profitable. If the Company is unable to obtain adequate capital, it could be forced to cease operations. At September 30, 2022, the Company had cash, cash equivalents, and marketable securities of $79.4 million. The Company expects that its existing cash and cash equivalents will enable it to fund its current operating expenses and capital expenditure requirements into 2024. However, the foregoing is subject to the Company’s continued compliance with the minimum cash covenant as set forth under the terms of its debt facility with K2 HealthVentures LLC (the “K2 Loan and Security Agreement”), which requires the Company to certify monthly that it has cash, cash equivalents and marketable securities of at least five times its monthly cash burn (the “ The Company has been, and currently is, in compliance with all covenants in the K2 Loan and Security Agreement, including the Minimum Cash Covenant. However, the Company currently anticipates that its existing cash, cash equivalents and marketable securities will not be sufficient to maintain compliance with the Minimum Cash Covenant beyond the one-year period following the date that the accompanying consolidated financial statements are issued, unless the Company reduces its operating expenses, raises additional capital or amends the K2 Loan and Security Agreement at some time during the third quarter of 2023. For this reason, management has included this going concern statement. Failure to meet the Minimum Cash Covenant would be considered an event of default under the K2 Loan and Security Agreement and could result in the acceleration of the Company’s existing indebtedness thereunder. In view of these conditions, the ability of the Company to continue as a going concern is in substantial doubt and dependent upon achieving a profitable level of operations and on the ability of the Company to obtain necessary financing to fund ongoing operations. Historically, the Company has relied upon partnerships as well as funds received from public offerings of common and preferred stock, private placements of equity securities, a reverse merger, and upfront and milestone payments received from our prior and current collaboration agreements, a debt financing facility, as well as funding from governmental bodies and bank and bridge loans. 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. However, there is no assurance that the Company will be successful in raising additional capital or that such additional funds will be available on acceptable terms, if at all. Should the Company be unable to raise this amount of capital its operating plans will be limited to the amount of capital that it can access. The Company may also consider steps to reduce its operating expenses and/or seek modification of the Minimum Cash Covenant in the K2 Loan and Security Agreement. There can be no assurances that the Company will be successful in any of the foregoing. These financial statements do not give effect to any adjustments which will be necessary should the Company be unable to continue as a going concern and therefore be required to realize its assets and discharge its liabilities in other than the normal course of business and at amounts different from those reflected in the accompanying financial statements. Significant Accounting Policies There have been no material changes to the Company’s significant accounting policies during the nine months ended September 30, 2022, as compared to the significant accounting policies disclosed in Note 1, “Summary of Significant Accounting Policies”, to the consolidated financial statements in the Company’s Annual Report on Form 10-K for the year ended December 31, 2021. Cash and Cash Equivalents The Company considers temporary investments having original maturities of three months or less from date of purchase to be cash equivalents. Restricted cash is recorded in other assets, based on when the restrictions expire. Other assets include $2.5 million of restricted cash at September 30, 2022 related to letters of credit in lieu of a cash deposit for the Company’s leases . Fair Value Measurement The Company accounts for its marketable securities in accordance with ASC 820 “Fair Value Measurements and Disclosures.” Level 1 —Quoted prices in active markets for identical assets or liabilities. Level 2 —Observable inputs other than Level 1 prices such as quoted prices for similar assets or liabilities, quoted prices in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. Level 3 —Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. The Company utilizes the market approach to measure fair value for its financial assets and liabilities. The market approach uses prices and other relevant information generated by market transactions involving identical or comparable assets or liabilities. For Level 2 securities that have market prices from multiples sources, a “consensus price” or a weighted average price for each of these securities can be derived from a distribution-curve-based algorithm which includes market prices obtained from a variety of industrial standard data providers (e.g. Bloomberg), security master files from large financial institutions, and other third-party sources. Level 2 securities with short maturities and infrequent secondary market trades are typically priced using mathematical calculations adjusted for observable inputs when available. Concentration of Credit Risk and Other Risks and Uncertainties Financial instruments that potentially subject the Company to concentrations of risk consist principally of cash and cash equivalents, investments, long term debt and accounts receivable. The Company’s cash and cash equivalents are with two major financial institutions in the United States. The Company performs an ongoing credit evaluation of its strategic partners’ financial conditions and generally does not require collateral to secure accounts receivable from its strategic partners. At September 30, 2022, the Company’s exposure to credit risk associated with non-payment will be affected principally by conditions or occurrences within Bristol Myers Squibb Company (“Bristol Myers Squibb”). In past years, Vertex Pharmaceuticals Incorporated (“Vertex”) 0% Bristol Myers Squibb Drug or biologic candidates developed by the Company may require approvals or clearances from the U.S. Food and Drug Administration (“FDA”) or international regulatory agencies prior to commercial sales. There can be no assurance that the Company’s drug or biologic candidates will receive any of the required approvals or clearances. If the Company were to be denied approval or clearance or any such approval or clearance were to be delayed, it would have a material adverse impact on the Company. Recently Issued Accounting Pronouncements In August 2020, the FASB issued ASU No. 2020-06, Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity (Subtopic 470-20: Debt with Conversion and Other Options and Subtopic 815-40: Derivatives and Hedging - Contracts in Entity’s Own Equity). The new guidance simplifies accounting for convertible instruments by removing major separation models, removes certain settlement conditions that are required for equity contracts to qualify for the derivative scope exception, and it also simplifies the diluted earnings per share calculation in certain areas. The amendment is effective for the Company for fiscal years beginning after December 15, 2023. The Company does not expect this to have a material impact since there are no material convertible instruments at this time. In November 2021, the FASB issued ASU No. 2021-10, “Government Assistance: Disclosures by Business Entities about Government Assistance”. The amendments in this Update improve financial reporting by requiring disclosures that increase the transparency of transactions with a government. The amendments require the following annual disclosures about transactions with a government that are accounted for by applying a grant or contribution accounting model by analogy (i) the type of transaction, (ii) the accounting for the transaction, and (iii) the effect of the transaction on the entity’s financial statements. The Company adopted this standard as of January 1, 2022, using a prospective approach and it did not have a material impact on the Company’s financial statements and related disclosures

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	NOTE 2 — NET LOSS PER COMMON SHARE Basic net loss per common share is computed by dividing net loss by the weighted-average number of common shares outstanding during the period utilizing the two-class method. Preferred Stock Shareholders participate equally with Common Stock Shareholders in earnings, but do not participate in losses, and are excluded from the basic net loss calculation. Diluted net loss per share is computed by giving effect to all potential dilutive common shares, including outstanding options, warrants and convertible preferred stock. More specifically, at September 30, 2022 and September 30, 2021, stock options, warrants and, if converted, preferred stock totaling approximately 11,988,000 and 11,696,000 common shares, respectively, were excluded from the computation of diluted net loss per share as their effect would have been anti-dilutive.

Research and Development Agreem

Research and Development Agreements	9 Months Ended
	Sep. 30, 2022
Research And Development [Abstract]
Research and Development Agreements	NOTE 3 — RESEARCH AND DEVELOPMENT AGREEMENTS Disaggregated Research and Development Revenue Research and development revenue is attributable to regions based on the location of each of the Company’s collaboration partner's parent company headquarters. Research and development revenues disaggregated by location were as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2022 2021 2022 2021 Japan $ — $ — $ 2,586 $ 13,136 United States 4,240 2,379 14,557 7,597 Total research and development revenue $ 4,240 $ 2,379 $ 17,143 $ 20,733 Collaboration Agreements Bristol Myers Squibb Collaboration Agreement In February 2021, the Company, entered into a Collaboration Agreement (the “BMS Collaboration Agreement”), as amended, with Bristol Myers Squibb Company (“Bristol Myers Squibb”) to perform strategic research collaboration leveraging the Company’s ETB technology platform to discover and develop novel products containing ETBs directed to multiple targets. Pursuant to the terms of the BMS Collaboration Agreement, the Company granted Bristol Myers Squibb a series of exclusive options to obtain one or more exclusive licenses under the Company’s intellectual property to exploit products containing ETBs directed against certain targets designated by Bristol Myers Squibb. Bristol Myers Squibb paid the Company an upfront payment of $70.0 million. In addition to the upfront payment, the Company may receive near term and development and regulatory milestone payments of up to $874.5 million. The Company will also be eligible to receive up to an additional $450.0 million in payments upon the achievement of certain sales milestones, and subject to certain reductions, tiered royalties ranging from mid-single digits up to mid-teens as percentages of calendar year net sales, if any, on any licensed product. The Company will be responsible for conducting the research activities through the designation, if any, of one or more development candidates. Upon the exercise of its option for a development candidate, Bristol Myers Squibb will be responsible for all development, manufacturing, regulatory and commercialization activities with respect to that development candidate. Unless earlier terminated, the BMS Collaboration Agreement will expire (i) on a country-by-country basis and licensed product-by-licensed product basis, on the date of expiration of the royalty payment obligations under the BMS Collaboration Agreement with respect to such licensed product in such country and (ii) in its entirety upon the earlier of (a) the expiration of the royalty payment obligations under the BMS Collaboration Agreement with respect to all licensed products in all countries or (b) upon Bristol Myers Squibb’s decision not to exercise any option on or prior to the applicable option deadlines. Bristol Myers Squibb has the right to terminate the BMS Collaboration Agreement for convenience upon prior written notice to the Company. Either party has the right to terminate the BMS Collaboration Agreement (a) for the insolvency of the other party or (b) subject to specified cure periods, in the event of the other party’s uncured material breach. The Company has the right upon prior written notice to terminate the BMS Collaboration Agreement in the event that Bristol Myers Squibb or any of its affiliates asserts a challenge against the Company’s patents. The Company identified multiple performance obligations at the inception of the BMS Collaboration Agreement consisting of research and development services and material rights related to additional developmental targets. The transaction price of $70.0 million was allocated to the performance obligations based upon their relative stand-alone selling price and will be recognized over time as the underlying research and development services are performed. The Company recognizes revenue for research and development services under the BMS Collaboration Agreement using a cost-based input measure. In applying the cost-based input method of revenue recognition, the Company will use actual costs incurred relative to budgeted costs expected to be incurred. These costs consist primarily of internal employee efforts and third-party contract costs. Revenue is recognized based on actual costs incurred as a percentage of total budgeted costs as the Company completes its performance obligation over the estimated service period. The Company had $38.1 million and $32.8 million of deferred revenue, current, at September 30, 2022 and December 31, 2021 respectively, related to the BMS Collaboration Agreement. The Company had $14.6 million and $30.7 million of deferred revenue, non-current at September 30, 2022 and December 31, 2021, respectively, related to the BMS Collaboration Agreement. Vertex Collaboration Agreement In November 2019, the Company entered into a Master Collaboration Agreement (the “Vertex Collaboration Agreement”) with Vertex Pharmaceuticals Incorporated (“Vertex”), to perform strategic research leveraging the Company’s ETB technology platform to discover and develop novel targeted biologic therapies for applications outside of oncology. In October 2021, the Company received a notice of termination from Vertex for the Vertex Collaboration Agreement. The termination of the Vertex Collaboration Agreement was effective in October 2021. There are no ongoing activities or economic obligations in connection with the Vertex Collaboration Agreement. With the termination of the agreement, the Company’s performance obligations under the Vertex Collaboration Agreement Collaboration Agreements - Takeda Research and development revenue from a previously related party was with Millennium Pharmaceuticals, Inc., a wholly owned subsidiary of Takeda Pharmaceutical Company Limited (“Takeda”) and were as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2022 2021 2022 2021 Takeda Development and License Agreement $ — $ — $ — $ 13,114 Takeda Multi-Target Agreement — — 2,586 22 Total research and development revenue, Takeda $ — $ — $ 2,586 $ 13,136 Takeda Development and License Agreement In September 2018, the Company entered into a Development Collaboration and Exclusive License Agreement, as amended, with Millennium Pharmaceuticals, Inc., a wholly owned subsidiary of Takeda Pharmaceutical Company Limited (“Takeda”), for the development and commercialization of products incorporating or comprised of one or more CD38 SLT-A fusion proteins (“Licensed Products”) for the treatment of patients with diseases such as multiple myeloma (the “Takeda Development and License Agreement”). In April 2021, the Company received a notice of termination from Takeda for the Takeda Development and License Agreement. F As of the same date, the Company assumed full rights to MT-0169, including full control of MT-0169 clinical development, per the terms of the terminated Takeda Development and License Agreement. Following the transfer of the full MT-0169 rights to the Company, the Company may owe low-single digit royalties on future net sales of MT-0169 to Takeda as well as to certain third-party licensors. The Company may also owe certain third-party licensors potential aggregate clinical and regulatory milestone payments of up to $22.25 million. The Company recognized revenue using a cost-based input measure. In applying the cost-based input method of revenue recognition, the Company used actual costs incurred relative to budgeted costs expected to be incurred for the combined performance obligation. These costs consist primarily of internal employee efforts and third-party contract costs. Revenue was recognized based on actual costs incurred as a percentage of total budgeted costs as the Company completes its performance obligation over the estimated service period. Takeda Multi-Target Agreement In June 2017, the Company entered into a Multi-Target Collaboration and License Agreement with Millennium Pharmaceuticals, Inc., a wholly owned subsidiary of Takeda (the “Takeda Multi-Target Agreement”), in which the Company agreed to collaborate with Takeda to identify and generate ETBs, against two targets designated by Takeda. I n March 2022, following the Company’s request to bring the agreement to an end, the Company and Takeda mutually agreed to terminate the Takeda Multi-Target Agreement. As a result of the termination, the Company regained full rights to pursue the targets worked on under the Takeda Multi-Target Agreement. There are no ongoing activities or economic obligations in connection with the Takeda Multi-Target Agreement. At September 30, 2022 there was no deferred revenue related to the performance obligation and at December 31, 2021, deferred revenue was $2.6 million, and the remaining unrecognized transaction price of $2.6 million was recognized as research and development revenue in the first quarter of 2022. Grant Agreements I n September 2018, the Company entered into a Cancer Research Agreement (the “CD38 CPRIT Agreement”) with the Cancer Prevention and Research Institute of Texas (“ was extended in September 2022, under which CPRIT awarded a to fund research of a cancer therapy involving a CD38 targeting ETB Pursuant to the CD38 CPRIT Agreement, the Company may also use such funds to develop a replacement CD38 targeting ETB, with or without a partner. During the nine months ended September 30, 2022 and nine months ended September 30, 2021, the Company recognized no grant revenue under this award. Qualified expenditures submitted for reimbursement in excess of amounts received are recorded as receivables in grant revenue receivable. At September 30, 2022 , the Company had recorded grant revenue receivable.

Related Party Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 2022
Related Party Transactions [Abstract]
Related Party Transactions	NOTE 4 — RELATED PARTY TRANSACTIONS Takeda In connection with the Takeda Multi-Target Agreement described in Note 3 “Research and Development Collaboration Agreements”, Takeda became a related party, following the Takeda Stock Purchase Agreement described in Note 11 “Stockholders’ Equity”, of the Company’s previously filed Annual Report on Form 10-K for the year ended December 31, 2021, filed with the SEC on March 29, 2022. Additionally, Jonathan Lanfear, a director of the Company, was the Vice President and Global Head of Oncology and Neuroscience Business Development for Takeda until September 25, 2020. In August 2021, Takeda ceased to be a related party after a sale of the above-mentioned shares.

Marketable Securities and Fair

Marketable Securities and Fair Value Measurements	9 Months Ended
	Sep. 30, 2022
Fair Value Disclosures [Abstract]
Marketable Securities and Fair Value Measurements	NOTE 5 —MARKETABLE SECURITIES AND FAIR VALUE MEASUREMENTS The following table sets forth the Company’s financial assets (cash equivalents and marketable securities) at fair value on a recurring basis (in thousands): Basis of Fair Value Measurements September 30, 2022 Level 1 Level 2 Level 3 Money market funds $ 20,189 $ 20,189 $ — $ — Commercial paper 36,036 — 36,036 — United States Treasury Bills 22,130 — 22,130 — Total $ 78,355 $ 20,189 $ 58,166 $ — Amounts included in: Cash and cash equivalents $ 21,187 Marketable securities, current 57,168 Total cash equivalents and marketable securities $ 78,355 Basis of Fair Value Measurements December 31, 2021 Level 1 Level 2 Level 3 Money market funds $ 24,058 $ 24,058 $ — $ — Commercial paper 103,113 — 103,113 — United States Treasury Bills 14,023 — 14,023 — Government-related debt securities 5,185 — 5,185 — Corporate Bonds 5,726 — 5,726 — Total $ 152,105 $ 24,058 $ 128,047 $ — Amounts included in: Cash and cash equivalents $ 25,058 Marketable securities, current 118,061 Marketable securities, non-current 8,986 Total cash equivalents and marketable securities $ 152,105 The Company invests in highly-liquid, investment-grade securities. The following is a summary of the Company’s available-for-sale securities (in thousands): September 30, 2022 Cost Basis Unrealized Gain Unrealized Loss Fair Value Cash equivalents - money market funds and commercial paper $ 21,187 $ — $ — $ 21,187 Marketable securities, current - commercial paper and Treasury bills 57,395 — (227 ) 57,168 December 31, 2021 Cost Basis Unrealized Gain Unrealized Loss Fair Value Cash equivalents - money market funds, commercial paper and corporate bonds $ 25,058 $ — $ — $ 25,058 Marketable securities, current - commercial paper, Treasury bills and corporate bonds $ 118,084 $ 6 $ (29 ) $ 118,061 Marketable securities, non-current - Treasury bills $ 9,011 $ — $ (25 ) $ 8,986 The following summarized the contractual maturities of the Company’s available-for-sale investments (in thousands): September 30, 2022 Cost Basis Fair Value Due in one year or less $ 78,582 $ 78,355 Due after one year through five years — — Total $ 78,582 $ 78,355 December 31, 2021 Cost Basis Fair Value Due in one year or less $ 143,142 $ 143,119 Due after one year through five years 9,011 8,986 Total $ 152,153 $ 152,105 The Company received no proceeds from the sale of available-for-sale securities for the nine months ended September 30, 2022 and September 30, 2021, respectively, and no

Balance Sheet Components

Balance Sheet Components	9 Months Ended
	Sep. 30, 2022
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Balance Sheet Components	NOTE 6 — BALANCE SHEET COMPONENTS Accrued liabilities consisted of the following (in thousands): September 30, 2022 December 31, 2021 Accrued liabilities: General and administrative $ 1,061 $ 794 Clinical trial related costs 830 1,134 Non-clinical research and manufacturing operations 2,691 2,153 Payroll related 4,254 5,388 Other accrued expenses 54 46 Total Accrued liabilities $ 8,890 $ 9,515

Property and Equipment

Property and Equipment	9 Months Ended
	Sep. 30, 2022
Property Plant And Equipment [Abstract]
Property and Equipment	NOTE 7—PROPERTY AND EQUIPMENT Property and equipment consists of the following (in thousands): September 30, December 31, 2022 2021 Laboratory equipment $ 21,797 $ 19,211 Leasehold improvements 12,808 12,822 Furniture and fixtures 545 471 Computer and equipment 693 658 35,843 33,162 Less: Accumulated depreciation (19,496 ) (13,853 ) Total property and equipment, net $ 16,347 $ 19,309 Depreciation expense was $2.0 million and $1.7 million for the three months ended September 30, 2022 and September 30, 2021, respectively and $5.7 million and $4.8 million for the nine months ended September 30, 2022 and September 30, 2021. In connection with the continued expansion of the Company’s facilities, at September 30, 2022 and December 31, 2021, the Company had net Asset Retirement Obligation (

Borrowing Arrangements

Borrowing Arrangements	9 Months Ended
	Sep. 30, 2022
Debt Disclosure [Abstract]
Borrowing Arrangements	NOTE 8 — BORROWING ARRANGEMENTS Perceptive Credit Facility On February 27, 2018, the Company entered into a term loan facility with Perceptive Credit Holdings II, LP (“Perceptive”) in the amount of $10.0 million (the “Perceptive Credit Facility”). The Perceptive Credit Facility consisted of a $5.0 million term loan, which was drawn on the effective date of the Perceptive Credit Facility, and an additional $5.0 million term loan which the Company did not draw down. The principal on the facility accrued interest at an annual rate equal to a three-month LIBOR plus the Applicable Margin. The Applicable Margin was 11.00%. Upon the occurrence, and during the continuance, of an event of default, the Applicable Margin, defined above, would be increased by 4.00% per annum. Payments for the first 24 months were interest only and were paid quarterly. After the second anniversary of the closing date of the Perceptive Credit Facility, principal payments of $0.2 million were due each calendar quarter. The Company incurred $0.5 million in deferred finance costs and issued the debt net of a $1.5 million discount, in connection with the credit facility . The Company repaid the Perceptive Credit Facility on May 21, 2020, from the proceeds of the K2 Loan and Security Agreement discussed below. Upon the termination of the Perceptive Credit Facility, the Company paid $4.9 million in principal and interest and $0.1 million in exit fees and prepayment penalties. The Company recognized a total loss on extinguishment of debt in the amount of $1.2 million related to the Perceptive Credit Facility, during the year ended December 31, 2020. In connection with the Perceptive Credit Facility, on February 27, 2018, the Company issued Perceptive a warrant to purchase 190,000 shares of the Company’s common stock. The warrant is exercisable for a period of seven years from the date of issuance at an exercise price per share of $9.5972, subject to certain adjustments as specified in the Warrant. For further discussion of the warrant, see Note 11, “Stockholders’ Equity” to the Company’s audited consolidated financial statements for the year ended December 31, 2021, included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2021, filed with the SEC on March 29, 2022. The fair value of the warrant of $1.5 million was recorded as a debt discount at issuance and was included in the loss on extinguishment K2 HealthVentures Loan and Security Agreement In May 2020, the Company entered into the K2 Loan and Security Agreement in the amount of $45.0 million. The K2 Loan and Security Agreement was drawable in three tranches and to date the Company has drawn down $35.0 million with the remaining tranche of $10.0 million having lapsed as of December 31, 2021. Pursuant to the terms of the K2 Loan and Security Agreement, the principal accrues interest at an annual rate equal to the greater of 8.45% or the sum of the Prime Rate plus 5.2%. In April 2022, the K2 Loan and Security Agreement was amended in exchange for a $0.3 million amendment fee so that (i) payments will be interest only until the loan’s maturity date of June 1, 2024 , and (ii) the Minimum Cash Covenant will apply for the entire term of the K2 Loan and Security Agreement. This amendment resulted in a debt modification with the $0.3 million amendment fee recorded as a debt discount. The K2 Loan and Security Agreement includes both financial and non-financial covenants . The Company recorded the debt net of $2.8 million comprised of deferred financing costs, debt discount and associated exit fee which are being accreted to interest expense over the term of the K2 Loan and Security Agreement using the effective interest method. Additionally, the Company incurred $0.2 million in facilities fee related to the second tranche which was previously classified as a prepaid asset. As of September 30, 2022 and December 31, 2021, the K2 Loan principal balance was $35.0 million and $35.0 million, respectively. As of September 30, 2022 and December 31, 2021, the carrying value of long-term debt was $35.9 million and $35.5 million, respectively. Future required principal and final payments on the K2 Loan were as follows at September 30, 2022 ($ in thousands): 2022 (remaining) $ — 2023 — 2024 35,000 Total Principal Amounts 35,000 Final Fee Due at Maturity 2,318 Unamortized discount, deferred costs and final fee (1,378 ) Total Long-Term Debt, net $ 35,940

Leases

Leases	9 Months Ended
	Sep. 30, 2022
Leases [Abstract]
Leases	NOTE 9 – LEASES The Company has operating leases for administrative offices and research and development facilities, and certain finance leases for equipment. The operating leases have remaining terms of less than one year to less than seven years In September 2021, the Company permanently vacated its office space of approximately 10,000 square feet in Jersey City, New Jersey. The space was vacated because employees have transitioned to long-term remote working arrangements or the Company’s office space in New York, New York. The abandonment of leased space is an indicator of impairment and the Company assessed the lease ROU asset for impairment. In July 2022, the Company exercised its option to extend the term for its lease of its principal executive office at 9301 Amberglen Blvd, Building J, Austin TX 78729 (the “Property”) for an additional five-year On October 18, 2022, the Company entered into that certain Fourth Amendment to Lease between the Company and NW Austin Office Partners LLC (the “Lease Amendment”) which amended the Lease Agreement to document the exercise of its option to extend the term of its lease of the Property for an additional six-year six-year The foregoing is a summary only, does not purport to be complete, may not contain all information that is of interest to the reader and is qualified in its entirety by reference to the full text of the Lease Amendment, incorporated by reference to Exhibit 10.1 to this Quarterly Report on Form 10-Q. The following table summarizes the components of lease expense for the three and nine months ended September 30, 2022 (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2022 2022 Operating leases Operating lease expense $ 684 $ 1,885 Variable lease expense 156 367 Total operating lease expense $ 840 $ 2,252 The following table summarizes the balance sheet classification of leases at September 30, 2022 (in thousands): Operating leases Operating lease right-of-use assets $ 11,120 Operating lease liabilities, current 1 $ 1,957 Operating lease liabilities, non-current 12,422 Total operating lease liabilities $ 14,379 1. Included in other current liabilities. The following table presents other information on leases as of September 30, 2022 and December 31, 2021: 2022 2021 Weighted average remaining lease term, operating leases 5.80 years 5.65 years Weighted average discount rate, operating leases 8.09% 7.02% Maturities of lease liabilities were as follows as of September 30, 2022 (in thousands): Operating Leases 2022 (remaining) $ 682 2023 3,122 2024 3,164 2025 3,121 2026 2,563 Thereafter 5,507 Total lease payments 18,159 Less: Imputed interest (3,780 ) Total lease liabilities $ 14,379 Supplemental cash flow information related to the Company’s leases were as follows (in thousands): Nine Months Ended September 30, 2022 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows operating leases $ 2,518

Contractual Commitments

Contractual Commitments	9 Months Ended
	Sep. 30, 2022
Commitments And Contingencies Disclosure [Abstract]
Contractual Commitments	NOTE 10 — CONTRACTUAL COMMITMENTS The Company has entered into project work orders for each of its clinical trials with clinical research organizations (each being a “CRO”) and related laboratory vendors. Under the terms of these agreements, the Company is required to pay certain upfront fees for direct services costs. Based on the particular agreement some of the fees may be for services yet to be rendered and are reflected as a current prepaid asset and have an unamortized balance of approximately $0.4 million at September 30, 2022. In connection with the Company’s clinical trials, it has entered into separate project work orders for each trial with its respective CROs. The Company has entered into agreements with CROs and other external service providers for services, primarily in connection with the clinical trials and development of the Company’s drug or biologic candidates. The Company was contractually obligated for up to approximately $48.4 million of future services under these agreements at September 30, 2022, for which amounts have not been accrued as services have not been performed. The Company’s actual contractual obligations will vary depending upon several factors, including the progress and results of the underlying services. The Company has entered into estimated purchase obligations, which include signed orders for capital equipment. These estimated purchase obligations total in range from $8.4 million to $9.1 million.

Stock Based Compensation

Stock Based Compensation	9 Months Ended
	Sep. 30, 2022
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock Based Compensation	NOTE 11 — STOCK-BASED COMPENSATION Stock-based compensation expense, which consists of the compensation cost for employee stock options and the value of options issued to non-employees for services rendered, was allocated to research and development and general and administrative in the consolidated statements of operations as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2022 2021 2022 2021 Research and development $ 1,381 $ 2,377 $ 4,753 $ 6,791 General and administrative 1,260 1,866 4,552 6,031 Total stock-based compensation $ 2,641 $ 4,243 $ 9,305 $ 12,822 At September 30, 2022, the total unrecognized compensation cost related to unvested stock-based awards granted to employees under the Company’s equity incentive plans was approximately $20.1 million. This cost will be recorded as compensation expense on a ratable basis over the remaining weighted average requisite service period of approximately 2.43 years. Valuation Assumptions The Company estimated the fair value of stock options granted using the Black-Scholes option-pricing formula and a single option award approach. This fair value is being amortized ratably over the requisite service periods of the awards, which is generally the vesting period. The fair value of employee stock options was estimated using the following weighted-average assumptions: Three Months Ended September 30, Nine Months Ended September 30, 2022 2021 2022 2021 Employee Stock Options: Risk-free interest rate 3.25 % 1.17 % 2.33 % 0.92 % Expected term (in years) 6.08 6.08 6.08 6.08 Dividend yield — — — — Volatility 83.32 % 114.06 % 88.70 % 113.23 % Weighted-average fair value of stock options granted $ 0.53 $ 5.62 $ 1.66 $ 11.00 Equity Incentive Plans These plans consist of the 2018 Equity Incentive Plan, the 2014 Equity Incentive Plan, as amended; the 2004 Amended and Restated Equity Incentive Plan; and the Amended and Restated 2004 Employee Stock Purchase Plan. As of May 31, 2018, the 2014 Equity Incentive Plan; and the 2004 Amended and Restated Equity Incentive Plan were terminated, and no further shares will be granted from those plans. The following table summarizes stock option activity under the Company’s equity incentive plans: Outstanding Options Number of Shares Weighted Average Exercise Price Weighted Average Remaining Contractual Term Aggregate Intrinsic Value (in millions): Balances, December 31, 2020 6,697,927 $ 9.13 7.76 $ 13.79 Granted 2,683,818 $ 12.84 Exercised (320,716 ) $ 5.05 Cancelled (1,206,556 ) $ 11.46 Balances, December 31, 2021 7,854,473 $ 10.21 6.72 $ 0.95 Granted 2,890,789 $ 2.22 Exercised (46,598 ) $ 0.71 Cancelled (2,105,531 ) $ 9.58 Balances, September 30, 2022 8,593,133 $ 7.73 7.53 $ 0.01 Vested and expected to vest, September 30, 2022 8,593,133 $ 7.73 7.53 $ 0.01 Exercisable at September 30, 2022 4,605,401 $ 8.90 6.35 $ — The total intrinsic value of stock options exercised during the three months ended September 30, 2022 and 2021, was zero and $1.2 million, respectively, as determined at the date of the option exercise. Cash received from stock option exercises was zero and $1.6 million for the nine months ended September 30, 2022 and 2021, respectively. The Company issues new shares of common stock upon exercise of options. In connection with these exercises, there was no tax benefit realized by the Company due to the Company’s current loss position.

Organization and Summary of S_2

Organization and Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2022
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America and include the accounts of the Company and its wholly owned subsidiary and reflect the elimination of intercompany accounts and transactions. The preparation of condensed consolidated financial statements requires management to make estimates and assumptions that affect the recorded amounts reported therein. A change in facts or circumstances surrounding the estimates could result in a change to estimates and impact future operating results. Certain accounts in the prior financial statements have been reclassified for comparative purposes to conform to the presentation in the current financial statements. These reclassifications have no material effect on previously reported financials. The unaudited condensed consolidated financial statements and related disclosures have been prepared with the presumption that users of the interim unaudited condensed consolidated financial statements have read or have access to the audited consolidated financial statements for the preceding fiscal year. Accordingly, these unaudited condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto for the year ended December 31, 2021 included in the Company’s Annual Report on Form 10-K filed with the SEC on March 29, 2022.
Going Concern	Going Concern The Company has adopted as required the Financial Accounting Standards Board (FASB) Accounting Standards Codification (ASC) Topic 205-40, Presentation of Financial Statements - Going Concern, which requires that management contemplate the realization of assets and liquidation of liabilities in the normal course of business, and evaluate whether there are relevant conditions and events that in aggregate raise substantial doubt about the entity’s ability to continue as a going concern and to meet its obligations as they become due within one year after the date that the financial statements are issued. Under this standard, management’s assessment shall not take into consideration the potential mitigating effects of management’s plans that have not been fully implemented as of the date the financial statements are issued. The Company has not yet established an ongoing source of revenues sufficient to cover its operating costs and to provide sufficient certainty that it will continue as a going concern. As of September 30, 2022, the Company had an accumulated deficit of $422.7 million. The ability of the Company to continue as a going concern is dependent on the Company obtaining adequate capital to fund operating losses until it becomes profitable. If the Company is unable to obtain adequate capital, it could be forced to cease operations. At September 30, 2022, the Company had cash, cash equivalents, and marketable securities of $79.4 million. The Company expects that its existing cash and cash equivalents will enable it to fund its current operating expenses and capital expenditure requirements into 2024. However, the foregoing is subject to the Company’s continued compliance with the minimum cash covenant as set forth under the terms of its debt facility with K2 HealthVentures LLC (the “K2 Loan and Security Agreement”), which requires the Company to certify monthly that it has cash, cash equivalents and marketable securities of at least five times its monthly cash burn (the “ The Company has been, and currently is, in compliance with all covenants in the K2 Loan and Security Agreement, including the Minimum Cash Covenant. However, the Company currently anticipates that its existing cash, cash equivalents and marketable securities will not be sufficient to maintain compliance with the Minimum Cash Covenant beyond the one-year period following the date that the accompanying consolidated financial statements are issued, unless the Company reduces its operating expenses, raises additional capital or amends the K2 Loan and Security Agreement at some time during the third quarter of 2023. For this reason, management has included this going concern statement. Failure to meet the Minimum Cash Covenant would be considered an event of default under the K2 Loan and Security Agreement and could result in the acceleration of the Company’s existing indebtedness thereunder. In view of these conditions, the ability of the Company to continue as a going concern is in substantial doubt and dependent upon achieving a profitable level of operations and on the ability of the Company to obtain necessary financing to fund ongoing operations. Historically, the Company has relied upon partnerships as well as funds received from public offerings of common and preferred stock, private placements of equity securities, a reverse merger, and upfront and milestone payments received from our prior and current collaboration agreements, a debt financing facility, as well as funding from governmental bodies and bank and bridge loans. 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. However, there is no assurance that the Company will be successful in raising additional capital or that such additional funds will be available on acceptable terms, if at all. Should the Company be unable to raise this amount of capital its operating plans will be limited to the amount of capital that it can access. The Company may also consider steps to reduce its operating expenses and/or seek modification of the Minimum Cash Covenant in the K2 Loan and Security Agreement. There can be no assurances that the Company will be successful in any of the foregoing. These financial statements do not give effect to any adjustments which will be necessary should the Company be unable to continue as a going concern and therefore be required to realize its assets and discharge its liabilities in other than the normal course of business and at amounts different from those reflected in the accompanying financial statements.
Significant Accounting Policies	Significant Accounting Policies There have been no material changes to the Company’s significant accounting policies during the nine months ended September 30, 2022, as compared to the significant accounting policies disclosed in Note 1, “Summary of Significant Accounting Policies”, to the consolidated financial statements in the Company’s Annual Report on Form 10-K for the year ended December 31, 2021.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers temporary investments having original maturities of three months or less from date of purchase to be cash equivalents. Restricted cash is recorded in other assets, based on when the restrictions expire. Other assets include $2.5 million of restricted cash at September 30, 2022 related to letters of credit in lieu of a cash deposit for the Company’s leases .
Fair Value Measurement	Fair Value Measurement The Company accounts for its marketable securities in accordance with ASC 820 “Fair Value Measurements and Disclosures.” Level 1 —Quoted prices in active markets for identical assets or liabilities. Level 2 —Observable inputs other than Level 1 prices such as quoted prices for similar assets or liabilities, quoted prices in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. Level 3 —Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. The Company utilizes the market approach to measure fair value for its financial assets and liabilities. The market approach uses prices and other relevant information generated by market transactions involving identical or comparable assets or liabilities. For Level 2 securities that have market prices from multiples sources, a “consensus price” or a weighted average price for each of these securities can be derived from a distribution-curve-based algorithm which includes market prices obtained from a variety of industrial standard data providers (e.g. Bloomberg), security master files from large financial institutions, and other third-party sources. Level 2 securities with short maturities and infrequent secondary market trades are typically priced using mathematical calculations adjusted for observable inputs when available.
Concentration of Credit Risk and Other Risks and Uncertainties	Concentration of Credit Risk and Other Risks and Uncertainties Financial instruments that potentially subject the Company to concentrations of risk consist principally of cash and cash equivalents, investments, long term debt and accounts receivable. The Company’s cash and cash equivalents are with two major financial institutions in the United States. The Company performs an ongoing credit evaluation of its strategic partners’ financial conditions and generally does not require collateral to secure accounts receivable from its strategic partners. At September 30, 2022, the Company’s exposure to credit risk associated with non-payment will be affected principally by conditions or occurrences within Bristol Myers Squibb Company (“Bristol Myers Squibb”). In past years, Vertex Pharmaceuticals Incorporated (“Vertex”) 0% Bristol Myers Squibb Drug or biologic candidates developed by the Company may require approvals or clearances from the U.S. Food and Drug Administration (“FDA”) or international regulatory agencies prior to commercial sales. There can be no assurance that the Company’s drug or biologic candidates will receive any of the required approvals or clearances. If the Company were to be denied approval or clearance or any such approval or clearance were to be delayed, it would have a material adverse impact on the Company.
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements In August 2020, the FASB issued ASU No. 2020-06, Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity (Subtopic 470-20: Debt with Conversion and Other Options and Subtopic 815-40: Derivatives and Hedging - Contracts in Entity’s Own Equity). The new guidance simplifies accounting for convertible instruments by removing major separation models, removes certain settlement conditions that are required for equity contracts to qualify for the derivative scope exception, and it also simplifies the diluted earnings per share calculation in certain areas. The amendment is effective for the Company for fiscal years beginning after December 15, 2023. The Company does not expect this to have a material impact since there are no material convertible instruments at this time. In November 2021, the FASB issued ASU No. 2021-10, “Government Assistance: Disclosures by Business Entities about Government Assistance”. The amendments in this Update improve financial reporting by requiring disclosures that increase the transparency of transactions with a government. The amendments require the following annual disclosures about transactions with a government that are accounted for by applying a grant or contribution accounting model by analogy (i) the type of transaction, (ii) the accounting for the transaction, and (iii) the effect of the transaction on the entity’s financial statements. The Company adopted this standard as of January 1, 2022, using a prospective approach and it did not have a material impact on the Company’s financial statements and related disclosures

Research and Development Agre_2

Research and Development Agreements (Tables)	9 Months Ended
	Sep. 30, 2022
Research And Development [Abstract]
Schedule of Research and Development Revenues Disaggregated by Location	Research and development revenue is attributable to regions based on the location of each of the Company’s collaboration partner's parent company headquarters. Research and development revenues disaggregated by location were as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2022 2021 2022 2021 Japan $ — $ — $ 2,586 $ 13,136 United States 4,240 2,379 14,557 7,597 Total research and development revenue $ 4,240 $ 2,379 $ 17,143 $ 20,733
Schedule of Research and Development Revenue from Related Party Relates to Revenue from Research and Development Agreements	Research and development revenue from a previously related party was with Millennium Pharmaceuticals, Inc., a wholly owned subsidiary of Takeda Pharmaceutical Company Limited (“Takeda”) and were as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2022 2021 2022 2021 Takeda Development and License Agreement $ — $ — $ — $ 13,114 Takeda Multi-Target Agreement — — 2,586 22 Total research and development revenue, Takeda $ — $ — $ 2,586 $ 13,136

Marketable Securities and Fai_2

Marketable Securities and Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2022
Fair Value Disclosures [Abstract]
Financial Assets at Fair Value on Recurring Basis	The following table sets forth the Company’s financial assets (cash equivalents and marketable securities) at fair value on a recurring basis (in thousands): Basis of Fair Value Measurements September 30, 2022 Level 1 Level 2 Level 3 Money market funds $ 20,189 $ 20,189 $ — $ — Commercial paper 36,036 — 36,036 — United States Treasury Bills 22,130 — 22,130 — Total $ 78,355 $ 20,189 $ 58,166 $ — Amounts included in: Cash and cash equivalents $ 21,187 Marketable securities, current 57,168 Total cash equivalents and marketable securities $ 78,355 Basis of Fair Value Measurements December 31, 2021 Level 1 Level 2 Level 3 Money market funds $ 24,058 $ 24,058 $ — $ — Commercial paper 103,113 — 103,113 — United States Treasury Bills 14,023 — 14,023 — Government-related debt securities 5,185 — 5,185 — Corporate Bonds 5,726 — 5,726 — Total $ 152,105 $ 24,058 $ 128,047 $ — Amounts included in: Cash and cash equivalents $ 25,058 Marketable securities, current 118,061 Marketable securities, non-current 8,986 Total cash equivalents and marketable securities $ 152,105
Summary of Company's Available-for-Sale Securities	The Company invests in highly-liquid, investment-grade securities. The following is a summary of the Company’s available-for-sale securities (in thousands): September 30, 2022 Cost Basis Unrealized Gain Unrealized Loss Fair Value Cash equivalents - money market funds and commercial paper $ 21,187 $ — $ — $ 21,187 Marketable securities, current - commercial paper and Treasury bills 57,395 — (227 ) 57,168 December 31, 2021 Cost Basis Unrealized Gain Unrealized Loss Fair Value Cash equivalents - money market funds, commercial paper and corporate bonds $ 25,058 $ — $ — $ 25,058 Marketable securities, current - commercial paper, Treasury bills and corporate bonds $ 118,084 $ 6 $ (29 ) $ 118,061 Marketable securities, non-current - Treasury bills $ 9,011 $ — $ (25 ) $ 8,986
Summary of Contractual Maturities of Available-for-Sale-Investments	The following summarized the contractual maturities of the Company’s available-for-sale investments (in thousands): September 30, 2022 Cost Basis Fair Value Due in one year or less $ 78,582 $ 78,355 Due after one year through five years — — Total $ 78,582 $ 78,355 December 31, 2021 Cost Basis Fair Value Due in one year or less $ 143,142 $ 143,119 Due after one year through five years 9,011 8,986 Total $ 152,153 $ 152,105

Balance Sheet Components (Table

Balance Sheet Components (Tables)	9 Months Ended
	Sep. 30, 2022
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Components of Accrued Liabilities	Accrued liabilities consisted of the following (in thousands): September 30, 2022 December 31, 2021 Accrued liabilities: General and administrative $ 1,061 $ 794 Clinical trial related costs 830 1,134 Non-clinical research and manufacturing operations 2,691 2,153 Payroll related 4,254 5,388 Other accrued expenses 54 46 Total Accrued liabilities $ 8,890 $ 9,515

Property and Equipment (Tables)

Property and Equipment (Tables)	9 Months Ended
	Sep. 30, 2022
Property Plant And Equipment [Abstract]
Components of Property and Equipment	Property and equipment consists of the following (in thousands): September 30, December 31, 2022 2021 Laboratory equipment $ 21,797 $ 19,211 Leasehold improvements 12,808 12,822 Furniture and fixtures 545 471 Computer and equipment 693 658 35,843 33,162 Less: Accumulated depreciation (19,496 ) (13,853 ) Total property and equipment, net $ 16,347 $ 19,309

Borrowing Arrangements (Tables)

Borrowing Arrangements (Tables)	9 Months Ended
	Sep. 30, 2022
Debt Disclosure [Abstract]
Schedule of Required Future Principal Payments	Future required principal and final payments on the K2 Loan were as follows at September 30, 2022 ($ in thousands): 2022 (remaining) $ — 2023 — 2024 35,000 Total Principal Amounts 35,000 Final Fee Due at Maturity 2,318 Unamortized discount, deferred costs and final fee (1,378 ) Total Long-Term Debt, net $ 35,940

Leases (Tables)

Leases (Tables)	9 Months Ended
	Sep. 30, 2022
Leases [Abstract]
Components of Lease Expense	The following table summarizes the components of lease expense for the three and nine months ended September 30, 2022 (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2022 2022 Operating leases Operating lease expense $ 684 $ 1,885 Variable lease expense 156 367 Total operating lease expense $ 840 $ 2,252
Schedule of Balance Sheets Classification of Leases	The following table summarizes the balance sheet classification of leases at September 30, 2022 (in thousands): Operating leases Operating lease right-of-use assets $ 11,120 Operating lease liabilities, current 1 $ 1,957 Operating lease liabilities, non-current 12,422 Total operating lease liabilities $ 14,379 1. Included in other current liabilities.
Schedule of Leases Information	The following table presents other information on leases as of September 30, 2022 and December 31, 2021: 2022 2021 Weighted average remaining lease term, operating leases 5.80 years 5.65 years Weighted average discount rate, operating leases 8.09% 7.02%
Schedule of Maturities of Lease Liabilities	Maturities of lease liabilities were as follows as of September 30, 2022 (in thousands): Operating Leases 2022 (remaining) $ 682 2023 3,122 2024 3,164 2025 3,121 2026 2,563 Thereafter 5,507 Total lease payments 18,159 Less: Imputed interest (3,780 ) Total lease liabilities $ 14,379
Supplemental Cash Flow Information	Supplemental cash flow information related to the Company’s leases were as follows (in thousands): Nine Months Ended September 30, 2022 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows operating leases $ 2,518

Stock Based Compensation (Table

Stock Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2022
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-Based Compensation Expense	Stock-based compensation expense, which consists of the compensation cost for employee stock options and the value of options issued to non-employees for services rendered, was allocated to research and development and general and administrative in the consolidated statements of operations as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2022 2021 2022 2021 Research and development $ 1,381 $ 2,377 $ 4,753 $ 6,791 General and administrative 1,260 1,866 4,552 6,031 Total stock-based compensation $ 2,641 $ 4,243 $ 9,305 $ 12,822
Weighted-Average Fair Value Valuation Assumptions	The fair value of employee stock options was estimated using the following weighted-average assumptions: Three Months Ended September 30, Nine Months Ended September 30, 2022 2021 2022 2021 Employee Stock Options: Risk-free interest rate 3.25 % 1.17 % 2.33 % 0.92 % Expected term (in years) 6.08 6.08 6.08 6.08 Dividend yield — — — — Volatility 83.32 % 114.06 % 88.70 % 113.23 % Weighted-average fair value of stock options granted $ 0.53 $ 5.62 $ 1.66 $ 11.00
Summary of Stock Option Activity Under Equity Incentive Plan	The following table summarizes stock option activity under the Company’s equity incentive plans: Outstanding Options Number of Shares Weighted Average Exercise Price Weighted Average Remaining Contractual Term Aggregate Intrinsic Value (in millions): Balances, December 31, 2020 6,697,927 $ 9.13 7.76 $ 13.79 Granted 2,683,818 $ 12.84 Exercised (320,716 ) $ 5.05 Cancelled (1,206,556 ) $ 11.46 Balances, December 31, 2021 7,854,473 $ 10.21 6.72 $ 0.95 Granted 2,890,789 $ 2.22 Exercised (46,598 ) $ 0.71 Cancelled (2,105,531 ) $ 9.58 Balances, September 30, 2022 8,593,133 $ 7.73 7.53 $ 0.01 Vested and expected to vest, September 30, 2022 8,593,133 $ 7.73 7.53 $ 0.01 Exercisable at September 30, 2022 4,605,401 $ 8.90 6.35 $ —

Organization and Summary of S_3

Organization and Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Organization And Summary Of Significant Accounting Policies [Line Items]
Accumulated deficit	$ (422,719)		$ (422,719)		$ (352,050)
Cash, cash equivalents, and marketable securities	79,400		79,400
Restricted cash included in other assets	$ 2,489	$ 3,668	$ 2,489	$ 3,668
Restricted Cash and Cash Equivalents, Noncurrent, Statement of Financial Position [Extensible Enumeration]	Other assets	Other assets	Other assets	Other assets
ASU No. 2021-10
Organization And Summary Of Significant Accounting Policies [Line Items]
Change in Accounting Principle, Accounting Standards Update, Adopted [true false]	true		true
Change in Accounting Principle, Accounting Standards Update, Adoption Date	Jan. 01, 2022		Jan. 01, 2022
Change in Accounting Principle, Accounting Standards Update, Immaterial Effect [true false]	true		true
Revenue | Concentration of Credit Risk and Other Risks and Uncertainties | Vertex Pharmaceuticals Inc
Organization And Summary Of Significant Accounting Policies [Line Items]
Percentage of total revenues	0%	65%	0%	19%
Revenue | Concentration of Credit Risk and Other Risks and Uncertainties | Takeda Pharmaceuticals Inc
Organization And Summary Of Significant Accounting Policies [Line Items]
Percentage of total revenues	0%	0%	15%	63%
Revenue | Concentration of Credit Risk and Other Risks and Uncertainties | Bristol Myers Squibb
Organization And Summary Of Significant Accounting Policies [Line Items]
Percentage of total revenues	100%	35%	85%	18%

Net Loss Per Common Share - Add

Net Loss Per Common Share - Additional Information (Detail) - shares	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Stock Options, Warrants and Convertible Preferred Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Common shares excluded from the computation of diluted net loss per share on effect of anti-dilutive	11,988,000	11,696,000

Research and Development Agre_3

Research and Development Agreements - Schedule of Research and Development Revenues Disaggregated by Location (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Revenue Recognition [Line Items]
Total research and development revenue	$ 4,240	$ 2,379	$ 17,143	$ 20,733
JAPAN
Revenue Recognition [Line Items]
Total research and development revenue	0	0	2,586	13,136
UNITED STATES
Revenue Recognition [Line Items]
Total research and development revenue	$ 4,240	$ 2,379	$ 14,557	$ 7,597

Research and Development Agre_4

Research and Development Agreements - Additional Information (Detail) - USD ($)	1 Months Ended			3 Months Ended				9 Months Ended
	Aug. 31, 2021	Feb. 28, 2021	Sep. 30, 2018	Sep. 30, 2022	Mar. 31, 2022	Dec. 31, 2021	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Research And Development Collaboration Agreements [Line Items]
Research and development revenue recognized				$ 4,240,000			$ 2,379,000	$ 17,143,000	$ 20,733,000
Revenue from grant				4,240,000			$ 2,379,000	17,143,000	20,733,000
Grant
Research And Development Collaboration Agreements [Line Items]
Revenue from grant								0	$ 0
CPRIT Agreement | Cancer Prevention and Research Institute of Texas
Research And Development Collaboration Agreements [Line Items]
Product development grant awarded			$ 15,200,000
Grant Agreements | Grants Revenue Receivable
Research And Development Collaboration Agreements [Line Items]
Reimbursement amounts submitted in excess of amounts received are recorded as receivables				0		$ 0		0
Bristol Myers Squibb Collaboration Agreement
Research And Development Collaboration Agreements [Line Items]
Upfront payment		$ 70,000,000
Milestone payments receivable if option is exercised		874,500,000
Transaction price allocated to performance obligations		70,000,000
Deferred revenue, current				38,100,000		32,800,000		38,100,000
Deferred revenue, non-current				14,600,000		30,700,000		14,600,000
Bristol Myers Squibb Collaboration Agreement | Sales Milestone
Research And Development Collaboration Agreements [Line Items]
Milestone payments receivable if option is exercised		$ 450,000,000
Vertex Collaboration Agreement
Research And Development Collaboration Agreements [Line Items]
Research and development revenue recognized						14,600,000
Takeda Development Agreement | Maximum
Research And Development Collaboration Agreements [Line Items]
Clinical and regulatory milestone payments	$ 22,250,000
Takeda Multi Target Agreement | Takeda Pharmaceuticals Inc
Research And Development Collaboration Agreements [Line Items]
Research and development revenue recognized					$ 2,600,000
Deferred revenue				$ 0		$ 2,600,000		$ 0

Research and Development Agre_5

Research and Development Agreements - Schedule of Research and Development Revenue from Related Party Relates to Revenue from Research and Development Agreements (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Revenue Recognition [Line Items]
Total research and development revenue	$ 4,240	$ 2,379	$ 17,143	$ 20,733
Millennium Pharmaceuticals, Inc.
Revenue Recognition [Line Items]
Total research and development revenue	0	0	2,586	13,136
Millennium Pharmaceuticals, Inc. | Takeda Development Agreement
Revenue Recognition [Line Items]
Total research and development revenue	0	0	0	13,114
Millennium Pharmaceuticals, Inc. | Takeda Multi Target Agreement
Revenue Recognition [Line Items]
Total research and development revenue	$ 0	$ 0	$ 2,586	$ 22

Marketable Securities and Fai_3

Marketable Securities and Fair Value Measurements - Financial Assets at Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021	Sep. 30, 2021
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total cash equivalents and marketable securities	$ 78,355	$ 152,105
Cash and cash equivalents	22,277	24,983	$ 27,593
Marketable securities, current	57,168	118,061
Marketable securities, non-current		8,986
Money Market Funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total cash equivalents and marketable securities	20,189	24,058
Commercial Paper
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total cash equivalents and marketable securities	36,036	103,113
United States Treasury Bills
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total cash equivalents and marketable securities	22,130	14,023
Government-Related Debt Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total cash equivalents and marketable securities		5,185
Corporate Bonds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total cash equivalents and marketable securities		5,726
Cash Equivalents
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash and cash equivalents	21,187	25,058
Basis of Fair Value Measurements, Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total cash equivalents and marketable securities	20,189	24,058
Basis of Fair Value Measurements, Level 1 | Money Market Funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total cash equivalents and marketable securities	20,189	24,058
Basis of Fair Value Measurements, Level 1 | Commercial Paper
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total cash equivalents and marketable securities	0	0
Basis of Fair Value Measurements, Level 1 | United States Treasury Bills
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total cash equivalents and marketable securities	0	0
Basis of Fair Value Measurements, Level 1 | Government-Related Debt Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total cash equivalents and marketable securities		0
Basis of Fair Value Measurements, Level 1 | Corporate Bonds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total cash equivalents and marketable securities		0
Basis of Fair Value Measurements, Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total cash equivalents and marketable securities	58,166	128,047
Basis of Fair Value Measurements, Level 2 | Money Market Funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total cash equivalents and marketable securities	0	0
Basis of Fair Value Measurements, Level 2 | Commercial Paper
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total cash equivalents and marketable securities	36,036	103,113
Basis of Fair Value Measurements, Level 2 | United States Treasury Bills
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total cash equivalents and marketable securities	22,130	14,023
Basis of Fair Value Measurements, Level 2 | Government-Related Debt Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total cash equivalents and marketable securities		5,185
Basis of Fair Value Measurements, Level 2 | Corporate Bonds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total cash equivalents and marketable securities		5,726
Basis of Fair Value Measurements, Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total cash equivalents and marketable securities	0	0
Basis of Fair Value Measurements, Level 3 | Money Market Funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total cash equivalents and marketable securities	0	0
Basis of Fair Value Measurements, Level 3 | Commercial Paper
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total cash equivalents and marketable securities	0	0
Basis of Fair Value Measurements, Level 3 | United States Treasury Bills
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total cash equivalents and marketable securities	$ 0	0
Basis of Fair Value Measurements, Level 3 | Government-Related Debt Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total cash equivalents and marketable securities		0
Basis of Fair Value Measurements, Level 3 | Corporate Bonds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total cash equivalents and marketable securities		$ 0

Marketable Securities and Fai_4

Marketable Securities and Fair Value Measurements - Summary of Company's Available-for-Sale Securities (Detail) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Schedule Of Available For Sale Securities [Line Items]
Cost Basis	$ 78,582	$ 152,153
Fair Value	57,168	118,061
Fair Value	0	8,986
Money Market Funds And Commercial Paper
Schedule Of Available For Sale Securities [Line Items]
Cost Basis	21,187
Unrealized Gain	0
Unrealized Loss	0
Fair Value	21,187
Commercial Paper And Treasury Bills
Schedule Of Available For Sale Securities [Line Items]
Cost Basis	57,395
Unrealized Gain	0
Unrealized Loss	(227)
Fair Value	$ 57,168
Money Market Funds Commercial Paper And Corporate Bonds
Schedule Of Available For Sale Securities [Line Items]
Cost Basis		25,058
Unrealized Gain		0
Unrealized Loss		0
Fair Value		25,058
Commercial Paper Treasury Bills And Corporate Bonds
Schedule Of Available For Sale Securities [Line Items]
Cost Basis		118,084
Unrealized Gain		6
Unrealized Loss		(29)
Fair Value		118,061
Marketable Securities, Non-current - Treasury Bills
Schedule Of Available For Sale Securities [Line Items]
Cost Basis		9,011
Unrealized Gain		0
Unrealized Loss		(25)
Fair Value		$ 8,986

Marketable Securities and Fai_5

Marketable Securities and Fair Value Measurements - Summary of Contractual Maturities of Available-for-Sale-Investments (Detail) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Fair Value Disclosures [Abstract]
Fair Value, Due in one year or less	$ 78,355	$ 143,119
Fair Value, Due after one year through five years	0	8,986
Fair Value, Total	78,355	152,105
Cost Basis, Due in one year or less	78,582	143,142
Cost Basis, Due after one year through five years	0	9,011
Cost Basis	$ 78,582	$ 152,153

Marketable Securities and Fai_6

Marketable Securities and Fair Value Measurements - Additional Information (Detail) - USD ($)	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Investments Debt And Equity Securities [Abstract]
Proceeds from sale of available-for-sale securities	$ 0	$ 0
Available-for-sale securities, realized gain	$ 0	$ 0

Balance Sheet Components - Comp

Balance Sheet Components - Components of Accrued Liabilities (Detail) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Accrued liabilities:
General and administrative	$ 1,061	$ 794
Clinical trial related costs	830	1,134
Non-clinical research and manufacturing operations	2,691	2,153
Payroll related	4,254	5,388
Other accrued expenses	54	46
Total Accrued liabilities	$ 8,890	$ 9,515

Property and Equipment - Compon

Property and Equipment - Components of Property and Equipment (Detail) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Property Plant And Equipment [Line Items]
Property and equipment, Gross	$ 35,843	$ 33,162
Less: Accumulated depreciation	(19,496)	(13,853)
Total property and equipment, net	16,347	19,309
Laboratory Equipment
Property Plant And Equipment [Line Items]
Property and equipment, Gross	21,797	19,211
Leasehold Improvements
Property Plant And Equipment [Line Items]
Property and equipment, Gross	12,808	12,822
Furniture and Fixtures
Property Plant And Equipment [Line Items]
Property and equipment, Gross	545	471
Computer and Equipment
Property Plant And Equipment [Line Items]
Property and equipment, Gross	$ 693	$ 658

Property and Equipment - Additi

Property and Equipment - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Property Plant And Equipment [Line Items]
Depreciation expense	$ 2	$ 1.7	$ 5.7	$ 4.8
Leasehold Improvements
Property Plant And Equipment [Line Items]
Asset retirement obligation, asset	$ 0.3		$ 0.3		$ 0.6

Borrowing Arrangements - Additi

Borrowing Arrangements - Additional Information (Detail) - USD ($)			1 Months Ended	9 Months Ended
	May 31, 2020	Feb. 27, 2018	Apr. 04, 2022	Sep. 30, 2022	Dec. 31, 2021
Debt Instrument [Line Items]
Long-term debt, carrying value				$ 35,900,000	$ 35,500,000
Perceptive
Debt Instrument [Line Items]
Credit Facility, interest expense				4,900,000
Exit fees and prepayment penalties				100,000
Loss on extinguishment of debt				$ 1,200,000
K2 Loan and Security Agreement
Debt Instrument [Line Items]
Maximum borrowing capacity under loan	$ 45,000,000
Loan and security agreement	$ 35,000,000
Loan and security agreement, lapsed amount					10,000,000
Interest rate				8.45%
Amendment fee			$ 300,000
Debt net				$ 2,800,000
Debt instrument, covenant compliance				The Company was in compliance with the debt covenants at September 30, 2022.
Total debt				$ 35,000,000	$ 35,000,000
Long-term debt, carrying value				35,940,000
K2 Loan and Security Agreement | Loan Facility Tranche Two
Debt Instrument [Line Items]
Additionally incurred prepaid facilities fee				$ 200,000
K2 Loan and Security Agreement | Prime Rate
Debt Instrument [Line Items]
Interest rate				5.20%
Term Loan Facility | Perceptive
Debt Instrument [Line Items]
Maximum borrowing capacity under loan		$ 10,000,000
Increase in applicable margin percentage on event of default		4%
Period for which interest only payments will be made		24 months
Credit Facility, principal payments		$ 200,000
Deferred finance costs		500,000
Debt issuance cost, net of discount		$ 1,500,000
Number of shares issued for each warrant		190,000
Warrant exercisable period		7 years
Warrant exercise price		$ 9.5972
Fair value of the warrant recorded as a debt discount		$ 1,500,000
Term Loan Facility | Perceptive | LIBOR
Debt Instrument [Line Items]
Applicable margin percentage		11%
Term Loan Facility | Perceptive | Term Loan Drawn on Effective Date of Credit Facility
Debt Instrument [Line Items]
Proceeds from initial term loan on closing date of Credit Facility		$ 5,000,000
Term Loan Facility | Perceptive | Additional Term Loan Drawn Six Months Following Effective Date of Credit Facility
Debt Instrument [Line Items]
Remaining available amount from credit facility did not draw down		$ 5,000,000

Borrowing Arrangements - Schedu

Borrowing Arrangements - Schedule of Required Future Principal Payments (Detail) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Debt Instrument [Line Items]
Total Long-Term Debt, net	$ 35,900	$ 35,500
K2 Loan and Security Agreement
Debt Instrument [Line Items]
2022 (remaining)	0
2023	0
2024	35,000
Total Principal Amounts	35,000	$ 35,000
Final Fee Due at Maturity	2,318
Unamortized discount, deferred costs and final fee	(1,378)
Total Long-Term Debt, net	$ 35,940

Leases - Additional Information

Leases - Additional Information (Detail) $ in Millions	Oct. 18, 2022 USD ($)	Jul. 31, 2022	Sep. 30, 2022	Sep. 30, 2021 ft²
Lessee Lease Description [Line Items]
Lessee, operating leases renewal lease term			7 years
Lease Amendment | Subsequent Event
Lessee Lease Description [Line Items]
Additional extended lease term	6 years
Additional extended lease term beginning date	Aug. 31, 2023
Additional extended lease term end date	Aug. 31, 2029
Committed lease amount payment period	6 years
Option to extend lease term	7 years
Aggregated lease commitments	$ 6.7
Amount abated in installments from the monthly lease commitments	$ 0.2
New Jersey
Lessee Lease Description [Line Items]
Area of Land | ft²				10,000
Texas
Lessee Lease Description [Line Items]
Additional extended lease term		5 years
Additional extended lease term beginning date		Aug. 31, 2023
Additional extended lease term end date		Aug. 31, 2028
Minimum [Member]
Lessee Lease Description [Line Items]
Lessee, operating leases remaining lease term.			1 year
Maximum
Lessee Lease Description [Line Items]
Lessee, operating leases remaining lease term.			7 years

Leases - Components of Lease Ex

Leases - Components of Lease Expense (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2022
Leases [Abstract]
Operating lease expense	$ 684	$ 1,885
Variable lease expense	156	367
Total operating lease expense	$ 840	$ 2,252

Leases - Schedule of Balance Sh

Leases - Schedule of Balance Sheets Classification of Leases (Detail) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Operating leases
Operating lease right-of-use assets	$ 11,120	$ 8,608
Operating lease liabilities, current	$ 1,957
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	Other current liabilities
Operating lease liabilities, non-current	$ 12,422	$ 9,564
Total operating lease liabilities	$ 14,379

Leases - Schedule of Leases Inf

Leases - Schedule of Leases Information (Detail)	Sep. 30, 2022	Dec. 31, 2021
Leases [Abstract]
Weighted average remaining lease term, operating leases	5 years 9 months 18 days	5 years 7 months 24 days
Weighted average discount rate, operating leases	8.09%	7.02%

Leases - Schedule of Maturities

Leases - Schedule of Maturities of Lease Liabilities (Detail) $ in Thousands	Sep. 30, 2022 USD ($)
Lease payments
2022 (remaining)	$ 682
2023	3,122
2024	3,164
2025	3,121
2026	2,563
Thereafter	5,507
Total lease payments	18,159
Less: Imputed interest	(3,780)
Total lease liabilities	$ 14,379

Leases - Supplemental Cash Flow

Leases - Supplemental Cash Flow Information (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2022 USD ($)
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows operating leases	$ 2,518

Contractual Commitments - Addit

Contractual Commitments - Additional Information (Detail) $ in Millions	Sep. 30, 2022 USD ($)
Other Commitments [Line Items]
Upfront fees unamortized balance included in prepaid asset	$ 0.4
Contractual obligation	48.4
Minimum [Member]
Other Commitments [Line Items]
Estimated purchase obligation	8.4
Maximum
Other Commitments [Line Items]
Estimated purchase obligation	$ 9.1

Stock Based Compensation - Stoc

Stock Based Compensation - Stock-Based Compensation Expense (Detail) - 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	$ 2,641	$ 4,243	$ 9,305	$ 12,822
Research and Development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation	1,381	2,377	4,753	6,791
General and Administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation	$ 1,260	$ 1,866	$ 4,552	$ 6,031

Stock Based Compensation - Addi

Stock Based Compensation - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized compensation cost related to unvested stock-based awards granted to employees under the equity incentive plans	$ 20,100,000		$ 20,100,000
Unrecognized compensation cost related to unvested stock-based awards granted to employees under the equity incentive plans, period for recognition			2 years 5 months 4 days
Total intrinsic value of stock options exercised	$ 0	$ 1,200,000
Cash received from stock option exercises			$ 33,000	$ 1,582,000
Tax benefit realized upon exercise of option			0
Equity Incentive Plans
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Cash received from stock option exercises			$ 0	$ 1,600,000

Stock Based Compensation - Weig

Stock Based Compensation - Weighted-Average Fair Value Valuation Assumptions (Detail) - Employee Stock Options - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Risk-free interest rate	3.25%	1.17%	2.33%	0.92%
Expected term (in years)	6 years 29 days	6 years 29 days	6 years 29 days	6 years 29 days
Dividend yield	0%	0%	0%	0%
Volatility	83.32%	114.06%	88.70%	113.23%
Weighted-average fair value of stock options granted	$ 0.53	$ 5.62	$ 1.66	$ 11

Stock Based Compensation - Summ

Stock Based Compensation - Summary of Stock Option Activity Under Equity Incentive Plan (Detail) - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2022	Dec. 31, 2021	Dec. 31, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Outstanding Options Number of Shares, Beginning Balance	7,854,473	6,697,927
Number of Shares, Options granted	2,890,789	2,683,818
Number of Shares, Options exercised	(46,598)	(320,716)
Number of shares, Options cancelled	(2,105,531)	(1,206,556)
Outstanding Options Number of Shares, Ending Balance	8,593,133	7,854,473	6,697,927
Outstanding Options Number of Shares, Vested and expected to vest, September 30, 2022	8,593,133
Outstanding Options Number of Shares, Exercisable at September 30, 2022	4,605,401
Weighted Average Exercise Price, Beginning Balance	$ 10.21	$ 9.13
Weighted Average Exercise Price, Options granted	2.22	12.84
Weighted Average Exercise Price, Options exercised	0.71	5.05
Weighted Average Exercise Price, Options cancelled	9.58	11.46
Weighted Average Exercise Price, Ending Balance	7.73	$ 10.21	$ 9.13
Weighted Average Exercise Price, Vested and expected to vest, September 30, 2022	7.73
Weighted Average Exercise Price, Exercisable at September 30, 2022	$ 8.90
Weighted-Average Remaining Contractual Term, Outstanding	7 years 6 months 10 days	6 years 8 months 19 days	7 years 9 months 3 days
Weighted-Average Remaining Contractual Term, Vested and expected to vest, September 30, 2022	7 years 6 months 10 days
Weighted-Average Remaining Contractual Term, Exercisable at September 30, 2022	6 years 4 months 6 days
Aggregate Intrinsic Value, Outstanding	$ 10	$ 950	$ 13,790
Aggregate Intrinsic Value, Vested and expected to vest, September 30, 2022	10
Aggregate Intrinsic Value, Exercisable at September 30, 2022	$ 0