Codiak BioSciences (CDAKQ) 10-Q 3 Nov 22 2022 Q3 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	9 Months Ended
	Sep. 30, 2022	Oct. 27, 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
Entity Registrant Name	CODIAK BIOSCIENCES, INC.
Entity Central Index Key	0001659352
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		36,829,626
Entity Shell Company	false
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Title of 12(b) Security	Common Stock, par value $0.0001 per share
Trading Symbol	CDAK
Security Exchange Name	NASDAQ
Entity File Number	001-39615
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	47-4926530
Entity Address, Address Line One	35 CambridgePark Drive
Entity Address, Address Line Two	Suite 500
Entity Address, City or Town	Cambridge
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02140
City Area Code	617
Local Phone Number	949-4100
Document Quarterly Report	true
Document Transition Report	false

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2022	Jun. 30, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 51,762		$ 76,938
Prepaid manufacturing services	6,727		7,315
Prepaid expenses and other current assets	2,744		5,918
Total current assets	61,233		90,171
Property and equipment, net of accumulated depreciation of $14,990 and $11,809	20,538		23,479
Restricted cash	4,170		4,170
Operating right-of-use assets	20,955		21,957
Prepaid manufacturing services, net of current portion	27,500		31,893
Total assets	134,396		171,670
Current liabilities:
Accounts payable	1,956		1,838
Accrued expenses	8,126		9,703
Deferred revenue	1,363		12,963
Operating lease liabilities	3,011		2,661
Total current liabilities	14,456		27,165
Long-term liabilities:
Deferred revenue, net of current portion	17,317		30,686
Note payable, net of discount	25,693		25,430
Derivative liability - warrants	5,428
Operating lease liabilities, net of current portion	32,573		34,884
Total liabilities	95,467		118,165
Commitments and contingencies (Note 7)
Stockholders' equity:
Common stock, $0.0001 par value; 150,000,000 shares authorized as of September 30, 2022 and December 31, 2021; 36,829,626 and 22,383,830 shares issued and outstanding as of September 30, 2022 and December 31, 2021, respectively	4		2
Additional paid-in capital	398,253		378,750
Accumulated deficit	(359,328)		(325,247)
Total stockholders' equity	38,929	$ 44,398	53,505
Total liabilities and stockholders' equity	$ 134,396		$ 171,670

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Statement of Financial Position [Abstract]
Accumulated depreciation	$ 14,990	$ 11,809
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	150,000,000	150,000,000
Common stock, shares issued	36,829,626	22,383,830
Common stock, shares outstanding	36,829,626	22,383,830

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Revenue:
Total revenue	$ 522	$ 1,157	$ 26,371	$ 15,238
Operating expenses:
Research and development	10,847	15,467	37,893	47,436
General and administrative	6,563	7,186	20,634	20,711
Impairment of prepaid manufacturing services	4,508		4,508
Total operating expenses	21,918	22,653	63,035	68,147
Loss from operations	(21,396)	(21,496)	(36,664)	(52,909)
Other income (expense):
Interest expense	(758)	(689)	(2,007)	(2,091)
Interest income	119	4	157	18
Other income	35	479	1,711	1,163
Change in fair value of derivative liability - warrants	2,722		2,722
Total other income (expense), net	2,118	(206)	2,583	(910)
Net loss	$ (19,278)	$ (21,702)	$ (34,081)	$ (53,819)
Net loss per share attributable to common stockholders, basic	$ (0.77)	$ (0.97)	$ (1.46)	$ (2.49)
Net loss per share attributable to common stockholders, diluted	$ (0.77)	$ (0.97)	$ (1.46)	$ (2.49)
Weighted average common shares outstanding, basic	25,159,757	22,325,334	23,373,684	21,599,405
Weighted average common shares outstanding, diluted	25,159,757	22,325,334	23,373,684	21,599,405
Collaboration
Revenue:
Revenue	$ 28	$ 1,157	$ 25,877	$ 15,238
Grant
Revenue:
Revenue	$ 494		$ 494

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	At-The-Market Offering	Warrant	Public Offering	Common Stock	Common Stock At-The-Market Offering	Common Stock Warrant	Common Stock Public Offering	Additional Paid-in Capital	Additional Paid-in Capital At-The-Market Offering	Additional Paid-in Capital Warrant	Additional Paid-in Capital Public Offering	Accumulated Deficit
Beginning balance at Dec. 31, 2020	$ 14,567				$ 2				$ 302,655				$ (288,090)
Beginning balance, shares at Dec. 31, 2020					18,787,579
Exercise of options to purchase common stock	316								316
Exercise of options to purchase common stock, shares					46,807
Stock-based compensation	2,273								2,273
Issuance of common stock upon offering, net of issuance costs				$ 61,868								$ 61,868
Issuance of common stock upon offering, net of issuance costs, shares								3,162,500
Issuance costs related to common stock				$ (560)
Net loss	(10,308)												(10,308)
Ending balance at Mar. 31, 2021	68,716				$ 2				367,112				(298,398)
Ending balance, shares at Mar. 31, 2021					21,996,886
Beginning balance at Dec. 31, 2020	14,567				$ 2				302,655				(288,090)
Beginning balance, shares at Dec. 31, 2020					18,787,579
Net loss	(53,819)
Ending balance at Sep. 30, 2021	34,006				$ 2				375,913				(341,909)
Ending balance, shares at Sep. 30, 2021					22,361,305
Beginning balance at Mar. 31, 2021	68,716				$ 2				367,112				(298,398)
Beginning balance, shares at Mar. 31, 2021					21,996,886
Exercise of options to purchase common stock	2,454								2,454
Exercise of options to purchase common stock, shares					276,089
Stock-based compensation	2,690								2,690
Issuance costs related to common stock	(187)								(187)
Net loss	(21,809)												(21,809)
Ending balance at Jun. 30, 2021	51,864				$ 2				372,069				(320,207)
Ending balance, shares at Jun. 30, 2021					22,272,975
Exercise of options to purchase common stock	752								752
Exercise of options to purchase common stock, shares					88,330
Stock-based compensation	3,092								3,092
Net loss	(21,702)												(21,702)
Ending balance at Sep. 30, 2021	34,006				$ 2				375,913				(341,909)
Ending balance, shares at Sep. 30, 2021					22,361,305
Beginning balance at Dec. 31, 2021	53,505				$ 2				378,750				(325,247)
Beginning balance, shares at Dec. 31, 2021					22,383,830
Stock-based compensation	2,349								2,349
Issuance of common stock upon offering, net of issuance costs		$ 553								$ 553
Issuance of common stock upon offering, net of issuance costs, shares						110,037
Issuance costs related to common stock		$ (17)
Net loss	(8,028)												(8,028)
Ending balance at Mar. 31, 2022	48,379				$ 2				381,652				(333,275)
Ending balance, shares at Mar. 31, 2022					22,493,867
Beginning balance at Dec. 31, 2021	53,505				$ 2				378,750				(325,247)
Beginning balance, shares at Dec. 31, 2021					22,383,830
Issuance of common stock upon offering, net of issuance costs, shares		236,303
Net loss	(34,081)
Ending balance at Sep. 30, 2022	38,929				$ 4				398,253				(359,328)
Ending balance, shares at Sep. 30, 2022					36,829,626
Beginning balance at Mar. 31, 2022	48,379				$ 2				381,652				(333,275)
Beginning balance, shares at Mar. 31, 2022					22,493,867
Common stock issued under Employee Stock Purchase Plan (ESPP)	126								126
Common stock issued under Employee Stock Purchase Plan (ESPP), shares					51,664
Stock-based compensation	2,668								2,668
Net loss	(6,775)												(6,775)
Ending balance at Jun. 30, 2022	44,398				$ 2				384,446				(340,050)
Ending balance, shares at Jun. 30, 2022					22,545,531
Stock-based compensation	2,287								2,287
Issuance of common stock upon offering, net of issuance costs		$ 384	$ 11,138				$ 2			$ 384	$ 11,136
Issuance of common stock upon offering, net of issuance costs, shares						126,266	14,027,665
Issuance of common stock from restricted stock units					130,164
Issuance costs related to common stock	(491)	$ (12)
Net loss	(19,278)												(19,278)
Ending balance at Sep. 30, 2022	$ 38,929				$ 4				$ 398,253				$ (359,328)
Ending balance, shares at Sep. 30, 2022					36,829,626

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Parenthetical) $ in Thousands	3 Months Ended
	Sep. 30, 2022 USD ($)
Issuance of common stock upon offering, net of issuance costs	$ 491
Issuance of common stock, warrants	(2,722)
At-The-Market Offering
Issuance of common stock upon offering, net of issuance costs	12
Warrant
Issuance of common stock, warrants	$ 8,150

CONDENSED CONSOLIDATED STATEM_4

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2022	Sep. 30, 2021
Cash flows from operating activities:
Net loss		$ (34,081)	$ (53,819)
Adjustments to reconcile net loss to net cash from operating activities:
Stock-based compensation expense		7,304	8,055
Change in fair value of derivative liability - warrants	$ (2,722)	(2,722)
Impairment of prepaid manufacturing services	4,508	4,508
Non-cash interest expense		308	392
Depreciation and amortization expense		3,181	4,205
Non-cash manufacturing expense		462
Changes in operating assets and liabilities:
Prepaid expenses and other current assets		2,949	(651)
Prepaid manufacturing services		12
Operating right-of-use assets		1,003	745
Accounts payable		175	206
Accrued expenses		(1,725)	1,118
Deferred revenue		(24,970)	(11,953)
Operating lease liabilities		(1,962)	(920)
Net cash used in operating activities		(45,558)	(52,622)
Cash flows from investing activities:
Purchases of property and equipment		(362)	(2,913)
Net cash used in investing activities		(362)	(2,913)
Cash flows from financing activities:
Proceeds from exercise of common stock options			3,523
Net cash received from Employee Stock Purchase Program (ESPP)		126
Proceeds from issuance of common stock, net of issuance costs		20,618	61,681
Net cash provided by financing activities		20,744	65,204
Net (decrease) increase in cash, cash equivalents and restricted cash		(25,176)	9,669
Cash, cash equivalents and restricted cash, beginning of period		81,108	93,085
Cash, cash equivalents and restricted cash, end of period	55,932	55,932	102,754
Supplemental disclosures:
Cash paid for interest		1,696	1,713
Non-cash investing and financing activities:
Purchases of property and equipment included in accounts payable and accrued expenses		28	388
Offering costs included in accrued expenses		267
Issuance of derivative liability - warrants		8,150
Reconciliation to amounts within the consolidated balance sheets
Cash and cash equivalents	51,762	51,762	98,584
Restricted cash	4,170	4,170	4,170
Cash, cash equivalents and restricted cash at end of period	$ 55,932	$ 55,932	$ 102,754

Nature of the Business

Nature of the Business	9 Months Ended
	Sep. 30, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of the Business	1. Nature of the Business Codiak BioSciences, Inc. (collectively, with its consolidated subsidiaries, any of "Codiak", "we", "us", or the "Company") was incorporated in Delaware on June 12, 2015 and is headquartered in Cambridge, Massachusetts. Codiak is a clinical-stage biopharmaceutical company focused on pioneering the development of exosome-based therapeutics, a new class of medicines with the potential to transform the treatment of a wide spectrum of diseases with high unmet medical need. Exosomes have evolved as intercellular transfer mechanisms for complex, biologically active macromolecules and have emerged in recent years as a compelling potential drug delivery vehicle. By leveraging its deep understanding of exosome biology, the Company has developed its engineering and manufacturing platform (the "engEx Platform"), to expand upon the innate properties of exosomes to design, engineer and manufacture novel exosome therapeutics. Codiak has utilized its engEx Platform to generate a deep pipeline of engineered exosomes ("engEx exosomes") aimed at treating a broad range of diseases, including oncology, and infectious disease and rare disease. In September 2020, Codiak initiated clinical trials for two of its lead product candidates, exoSTING and exoIL-12, which were being developed to address oncology indications. In June 2022, the Company initiated a Phase 1 clinical trial of exoASO-STAT6, Codiak’s first systemically delivered exosome therapeutic candidate. In August 2022, the Company paused clinical trials for exoSTING and exoIL-12 to prioritize focus on its Phase 1 clinical trial for exoASO-STAT6 (see Note 13).To the Company's knowledge, exoSTING and exoIL-12 are the first engineered exosomes to enter clinical development. Since its inception, the Company has devoted substantially all of its resources to its research and development efforts, including activities to develop its engEx Platform, advance engEx product candidates into clinical trials, perform preclinical research to identify potential engEx product candidates, perform process development to refine Codiak’s exosome engineering and manufacturing processes, and provide general and administrative support for these operations. The Company has primarily funded its operations with proceeds from the sales of common stock, redeemable convertible preferred stock, collaborative and research arrangements with Jazz Pharmaceuticals Ireland Limited ("Jazz") and Sarepta Therapeutics, Inc. ("Sarepta") and its loan and security agreement with Hercules Capital, Inc. ("Hercules"). As of September 30, 2022, the Company has raised an aggregate of $ 168.2 million through the issuance of its redeemable convertible preferred stock and convertible debt, net of issuance costs, $ 24.6 million from its term loan facility with Hercules, net of issuance costs, and received $ 66.0 million in payments from its collaborations with Jazz and Sarepta. On October 16, 2020, the Company completed its initial public offering ("IPO"), pursuant to which it issued and sold 5,500,000 shares of its common stock at a public offering price of $ 15.00 per share, resulting in net proceeds of $ 74.4 million, after deducting underwriting discounts and commissions and other offering expenses. On February 17, 2021, the Company completed a follow-on public offering, pursuant to which it issued 3,162,500 shares of its common stock (inclusive of the exercise of the underwriter’s option to purchase 412,500 additional shares of common stock) at a public offering price of $ 21.00 per share, resulting in aggregate net proceeds of $ 61.7 million, after deducting underwriting discounts and commissions and other offering expenses. On September 15, 2022, the Company completed a follow-on public offering, pursuant to which it issued 14,027,665 shares of its common stock and accompanying warrants to purchase 14,027,665 shares of its common stock (inclusive of the partial exercise of the underwriter’s option to purchase 694,332 additional shares of common stock and accompanying warrants to purchase 694,332 additional shares of common stock) at a combined public offering price of $ 1.50 per share, resulting in aggregate net proceeds of $ 19.8 million, after deducting underwriting discounts and commissions and other offering expenses. During the nine-month period ended September 30, 2022, the Company raised $ 0.9 million utilizing an "at-the-market" offering facility, pursuant to which it sold 236,303 shares of its common stock. The Company has incurred significant operating losses and negative cash flows from operations since inception and expects to continue to incur operating losses for the foreseeable future. In addition, the Company anticipates that its expenses will increase significantly in connection with ongoing activities to support its engEx Platform development, drug discovery and preclinical and clinical development, in addition to creating a portfolio of intellectual property and providing administrative support. The Company does not expect to generate significant revenue from sales of its engEx product candidates unless and until clinical development has been successfully completed and regulatory approval is obtained. If the Company obtains regulatory approval for any of its investigational products, it expects to incur significant commercialization expenses. The Company has evaluated whether there are conditions and events, considered in the aggregate, that raise substantial doubt about its ability to continue as a going concern within one year after the date that the consolidated financial statements are issued. The Company expects that its cash and cash equival ents of $ 51.8 million as of September 30, 2022 will be insufficient to allow the Company to fund its current operating plan through at least the next 12 months from the issuance of these financial statements. Maintaining the Company's ongoing operations is dependent upon its ability to obtain additional financing, as to which it can make no assurance. These conditions raise substantial doubt about the Company’s ability to continue as a going concern for a period of at least one year from the date these financial statements are issued. Accordingly, the Company will be required to raise additional funds through an additional public equity financing, establish collaborations with or license its technology to other companies, or seek alternative means of financial support in order to continue to fund its operations in the future. There can be no assurance, however, that additional fundraising will be successful and available on terms acceptable to the Company, or at all. If the Company is unable to raise capital when needed or on attractive terms, it may be forced to delay, reduce, or eliminate certain costs related to its operations and research and development programs. The Company is subject to those risks associated with any biopharmaceutical company that has substantial expenditures for research and development. There can be no assurance that the Company’s research and development projects will be successful, that products developed will obtain necessary regulatory approval, or that any approved product will be commercially viable. In addition, the Company operates in an environment of rapid technological change and is largely dependent on the services of its employees and consultants. If the Company fails to become profitable or is unable to sustain profitability on a continuing basis, then it may be unable to continue its operations at planned levels and be forced to reduce its operations.

Summary of Basis of Presentatio

Summary of Basis of Presentation and Significant Accounting Policies	9 Months Ended
	Sep. 30, 2022
Accounting Policies [Abstract]
Summary of Basis of Presentation and Significant Accounting Policies	2. Summary of Basis of Presentation and Significant Accounting Policies Basis of Presentation and Principles of Consolidation The consolidated financial statements include the Company and its subsidiaries. All intercompany transactions and balances have been eliminated in consolidation. Use of Estimates We have made estimates and judgments affecting the amounts reported in our consolidated financial statements and the accompanying notes. On an ongoing basis, we evaluate our estimates, including critical accounting policies or estimates related to revenue recognition, stock-based compensation, accrued expenses, leases, gain upon derecognition, contingent consideration, prepaid manufacturing services, warrants and impairment assessments. We base our estimates on historical experience and various relevant assumptions that we believe to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. The actual results that we experience may differ materially from our estimates. Accounting Pronouncements and Significant Accounting Policies The Company reviews new accounting standards as they are issued by the FASB or other standard-setting bodies. As of September 30, 2022, the Company has not identified any new standards that it believes will have a material impact on the Company’s financial statements. Restructuring The Company records costs and liabilities associated with exit and disposal activities based on estimates of fair value in the period in which the liabilities are incurred. The Company evaluates and adjusts these costs as appropriate for changes in circumstances as additional information becomes available. Restructuring costs comprise severance costs related to workforce reductions. When employees are not required to provide service beyond the minimum retention period, employee termination benefits are accrued at the date management has committed to a plan of termination and employees have been notified of their termination dates and expected severance payments. Grant Revenue The Company received a grant award from the Coalition for Epidemic Preparedness Innovations ("CEPI") for research and development related activities that provide for payments for qualifying costs, which may include overhead and general and administrative costs. We recognize revenue from this agreement as we perform services under the arrangement when the funding is committed and the costs are deemed to qualify pursuant to the grant. Associated expenses are recognized when incurred as research and development expenses. The services being rendered under this agreement are part of the Company's primary operations. Revenues and related expenses are presented gross in the consolidated statements of operations as we have determined we are the primary obligor under the arrangements relative to the research and development services we perform. Derivative Liability - Warrants In September 2022, the Company completed a follow-on offering of common stock. In connection with the follow-on offering, each share of common stock issued was accompanied by a warrant to purchase a single share of common stock. These warrants are derivative financial instruments under ASC Topic 815, Derivatives and Hedging (“ASC 815”) and do not qualify for the scope exceptions from derivative accounting. These derivatives are recorded as liabilities at fair value each reporting date and the fair value is determined using the Black-Scholes option-pricing model. The warrants are initially recorded as a reduction to proceeds from the common stock issuance in additional paid-in-capital. The changes in fair value are recorded as a component of other (expense) income in the consolidated statements of operations. Significant inputs used to determine the fair value at execution and as of September 30, 2022, included the price per share of the Company’s common stock, expected terms of the derivative instruments, strike price of the derivative instrument, risk-free interest rate, and expected volatility of peer company common stock. Changes to these inputs could materially affect the valuation of the warrants. There were no other changes to the Company’s significant accounting policies during the nine months ended September 30, 2022.

Derecognition of Business

Derecognition of Business	9 Months Ended
	Sep. 30, 2022
Discontinued Operations and Disposal Groups [Abstract]
Derecognition of Business	3. Derecognition of Business Arrangement Summary On November 1, 2021, the Company entered into an Asset Purchase Agreement (the "APA") with Lonza Rockland, Inc. ("Lonza"). Under the terms of the APA, Lonza acquired all of the assets, properties and rights related to the Company’s business of manufacturing exosomes for use in clinical and non-clinical studies and the associated laboratory facility, with the exception of any activities associated with exosome modification and formulation. The closing of the transactions contemplated by the APA (the "Lonza Closing") occurred on November 15, 2021. In connection with the Lonza Closing, certain specialized manufacturing and quality personnel of the Company became employees of Lonza. In connection with the Lonza Closing, the Company entered into a Manufacturing Services Agreement (the "MSA") with Lonza, which became effective on November 15, 2021. Pursuant to the terms of the MSA, Lonza became the exclusive manufacturing partner for the production of the Company’s exosome products, subject to limited exceptions. As consideration for the transactions contemplated by the APA and the associated ancillary agreements, the Company is entitled to approximately $ 65.0 million worth of exosome manufacturing services for its clinical programs during the next four years . To the extent the Company elects to use any free and/or discounted manufacturing services available under the MSA, it would be responsible for bearing any accompanying materials costs, external costs and a handling fee. Lonza is permitted to terminate the MSA with 12 months advance notice provided at any time after November 15, 2023. Accordingly, the Company’s ability to utilize the free and discounted manufacturing services available under the MSA in periods beyond November 15, 2024 is subject to Lonza’s right to terminate. The MSA may also be terminated upon the occurrence of certain other events, including customary termination provisions. Concurrently with the Lonza Closing, the Company and Lonza executed a license and collaboration agreement (the "License Agreement") on November 15, 2021. Pursuant to the terms of the License Agreement, the Company granted to Lonza an exclusive, worldwide, perpetual and sublicensable license to its high-throughput exosome manufacturing intellectual property in the contract development and manufacturing field. The Company is eligible to receive from Lonza a double-digit percentage of future sublicensing revenues per the terms of the License Agreement . No sublicensing revenue had been received by the Company or earned by Lonza as of September 30, 2022. Also contemporaneous with the Lonza Closing, the Company and Lonza entered into a sublease agreement (the "Sublease Agreement"), pursuant to which Lonza subleased the premises at which the Company’s exosome manufacturing operations were located. The initial lease term commenced on November 15, 2021 and continues through November 30, 2024 . Under the terms of the Sublease Agreement, Lonza is obligated to pay the Company approximately $ 1.0 million of fixed rent charges per year, subject to a 2.8 % annual increase, plus certain operating expenses and other costs. The Company retained the primary obligation under the original lease upon execution of the Sublease Agreement. Upon termination of the MSA on or prior to December 31, 2025, some aspects of the transactions contemplated by the APA and related ancillary agreements are required to be reverted, including with respect to certain assets, properties and rights that were transferred to Lonza. Upon termination or expiration of the Sublease Agreement at any time after December 31, 2025, some aspects of the transactions contemplated by the APA and related ancillary agreements are subject to potential reversion at Lonza’s option, including with respect to certain assets, properties and rights that were transferred to Lonza. Accounting Analysis The APA and pertinent elements of the MSA, the License Agreement and the Sublease Agreement comprise a single transaction because they were entered into in contemplation of one another and designed to achieve an overall commercial effect. Together, the related transactions consummated amongst the multiple contracts culminate in the transfer of the Company’s exosome manufacturing operations to Lonza (the "Lonza Transfer Transaction"). The Lonza Transfer Transaction represents the disposition of a business. Accordingly, the Company applied the derecognition guidance in ASC 810 in accounting for the transaction since Lonza is not a customer for any aspect of the arrangement. The Company’s control over the exosome manufacturing business transferred to Lonza was lost upon the closing of the APA and related ancillary agreements on November 15, 2021. Therefore, the Company recognized a gain upon derecognition on November 15, 2021. The gain was calculated as the difference between: (i) the fair value of the non-cash consideration and (ii) the carrying amount of the underlying group of assets. Because Lonza is entitled to terminate the MSA for any or no reason with 12 months ’ notice after November 15, 2023, the Company determined that any non-cash consideration scheduled beyond November 15, 2024 is contingent consideration since its ability to utilize the associated free and discounted manufacturing services is subject to Lonza’s right to terminate. The Company also treated the sublicensing revenue that may become payable under the License Agreement as contingent consideration as the receipt of any such amounts is dependent on Lonza engaging in sublicensing transactions, which is not expected to be material. Neither of the elements of contingent consideration is required to be accounted for as a derivative instrument because either the payments do not meet the definition of a derivative or qualify for a scope exception from derivative accounting. Consequently, the consideration attributable to the Lonza Transfer Transaction is limited to the non-cash consideration due to the Company under the MSA and the sublicensing fees to which the Company is entitled under the License Agreement. The Company recorded the aggregate consideration, including the contingent consideration, at its fair value as of November 15, 2021. The aggregate fair value of the non-cash consideration represents the total discounted cash flows associated with the manufacturing expenditures expected to be avoided over the period the free and discounted services are available. The value of the costs that would otherwise be incurred was determined in reference to comparable costs charged by unrelated third parties. The Company also incorporated a breakage factor in deriving the estimated fair value of the non-cash consideration to reflect expectations around utilization by the Company and termination by Lonza. The Company classified the MSA as a Level 3 fair value measurement at the date of the closing of the transaction. The discounted cash flow approach relies primarily on Level 3 unobservable inputs, whereby expected future cash flows are discounted using a rate that includes assumptions regarding an entity’s average cost of debt and equity, incorporates expected future cash flows based on internal business plans, and applies certain assumptions about risk and uncertainties. As of November 15, 2021, the Company estimated the aggregate fair value of such non-cash consideration, including the associated contingent consideration, to be approximately $ 39.2 million. The Company does not expect to earn any significant sublicensing fees or other consideration from the transaction. Amounts payable under the Sublease Agreement based on the contractually stated rates approximate the fair value of the associated rights conveyed as of November 15, 2021. Therefore, the Company has accounted for the Sublease Agreement separately from the disposition of the business. No amount has been allocated from the other consideration in the arrangement to this element. The Company has recorded the aggregate fair value of the non-cash consideration as a prepaid manufacturing services asset as of November 15, 2021. The Company will amortize the prepaid manufacturing services asset as requested services are rendered by Lonza under the MSA, subject to impairment assessments. Such amount is classified as current or noncurrent based on the timing of when the associated services are expected to be utilized by the Company. Amounts expected to be consumed within the 12 months following September 30, 2022 are classified within current assets as prepaid manufacturing services as of September 30, 2022, while the remainder was classified as a noncurrent asset as of September 30, 202 2. The Company periodically assesses whether its prepaid manufacturing services asset is impaired based on its forecasted manufacturing needs. The use of the prepaid manufacturing services asset is heavily dependent on the continued progress of the Company’s current product candidates. Should there be changes to the Company’s forecasted manufacturing needs, the Company may be required to record an impairment charge. The Company has utilized $ 0.5 million of the prepaid manufacturing services for preliminary work as of September 30, 2022, which is recorded as research and development expenses . During the three and nine months ended September 30, 2022, the Company mutually agreed with Lonza to not utilize a portion of prepaid manufacturing services under the MSA in 2022. As the services were not being utilized, the Company recognized an impairment charge to the prepaid manufacturing services asset of $ 4.5 million, which is reflected in the consolidated statements of operations.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2022
Fair Value Disclosures [Abstract]
Fair Value Measurements	4. Fair Value Measurements The following tables present information about the Company’s assets measured at fair value on a recurring basis, and indicate the level of the fair value hierarchy utilized to determine such fair values (in thousands): SEPTEMBER 30, 2022 TOTAL LEVEL 1 LEVEL 2 LEVEL 3 NOT Liabilities: Derivative liability – warrants $ 5,428 $ — $ — $ 5,428 $ — $ 5,428 $ — $ — $ 5,428 $ — DECEMBER 31, 2021 TOTAL LEVEL 1 LEVEL 2 LEVEL 3 NOT Assets: Cash equivalents: Money market funds $ 67,603 $ — $ — $ — $ 67,603 $ 67,603 $ — $ — $ — $ 67,603 (1) Certain cash equivalents that are valued using the net asset value per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. As of September 30, 2022 the Company held no cash equivalents. As of December 31, 2021, the Company’s cash equivalents consisted of money market funds invested in U.S. Treasury securities with original maturities of less than 90 days from the date of purchase. Warrants The Company’s warrants are recorded as derivative liabilities, and are classified as Level 3 measurements under the fair value hierarchy. These derivatives are not actively traded and are valued using the Black-Scholes option-pricing model, which requires the use of subjective assumptions. The following inputs were used in the fair market valuation of warrants as of September 30, 2022: September 30, 2022 Risk-free rate (1) 4.06 % Expected term 4.96 Stock price (2) $ 0.78 Strike price (3) $ 1.88 Common stock volatility (4) 79.93 % Dividend yield (5) — % (1) Based on the U.S. Treasury yield curve, with terms commensurate with the expected term of the warrants. (2) The closing price of the Company's common stock on the last trading day of the quarter ended September 30, 2022. (3) As per the agreement for the warrant. (4) Expected volatility based on historical volatility of the Company's peer companies that are commensurate with the expected term of the warrants. (5) The Company has not paid and does not anticipate paying cash dividends on its shares of common stock in the foreseeable future; therefore, the expected dividend yield is assumed to be zero. The warrants are recorded at fair value at each reporting date and changes in fair value are recorded in other (expense) income, net within the Company's consolidated statements of operations. The following table reflects the change in the Company's Level 3 warrants from December 31, 2021 through September 30, 2022 (in thousands): Warrants (in thousands) Balance at December 31, 2021 $ — Issuance fair value at September 15, 2022 8,150 Change in fair value, recorded as a gain on derivative liability - warrants ( 2,722 ) Balance at September 30, 2022 $ 5,428

Accrued Expenses

Accrued Expenses	9 Months Ended
	Sep. 30, 2022
Payables and Accruals [Abstract]
Accrued Expenses	5. Accrued Expenses Accrued expenses consist of the following (in thousands): SEPTEMBER 30, DECEMBER 31, Employee compensation $ 4,266 $ 5,142 External research and development costs 2,045 2,420 Professional services and consulting 1,201 1,523 Facilities costs 263 190 Other expenditures 351 428 $ 8,126 $ 9,703

Leases

Leases	9 Months Ended
	Sep. 30, 2022
Leases [Abstract]
Leases	6. Leases The Company has several long-term non-cancelable lease arrangements for its facilities, expiring at various times through 2029 . Certain arrangements have free rent periods or escalating rent payment provisions; costs under such arrangements are recognized on a straight-line basis over the life of the leases. The Company has two locations in Massachusetts, its office and laboratory, located in Cambridge and manufacturing space, located in Lexington, which is currently being leased and operated by Lo nza (see Note 3). Operating Leases 4 Hartwell Place On March 5, 2019, the Company entered into a lease for manufacturing space at 4 Hartwell Place in Lexington, Massachusetts. Under the terms of the lease, the Company leases 18,707 square feet for $ 0.9 million per year in base rent, which is subject to a 2.6 % annual rent increase during the initial lease term, plus certain operating expenses and taxes. The lease term commenced in July 2019 and will end in December 2029 . The Company has the option to extend the lease twice, each for a five-year period, on the same terms and conditions as the current lease, subject to a change in base rent based on market rates. The Company had fully occupied the space as of December 31, 2020. Upon execution of the lease agreement, the Company provided a security deposit of $ 0.4 million, which is held in the form of a letter of credit and was classified as non-current restricted cash as of September 30, 2022 and December 31, 2021. The lease provided the Company with a tenant improvement allowance of $ 1.3 million, which is being amortized as a reduction to rent expense over the remaining lease term. As of September 30, 2021, the Company had received all $ 1.3 million of the tenant improvement allowance. Costs incurred related to the allowance are capitalized as leasehold improvements. On November 15, 2021, the Company entered into an amendment to the lease (the "Master Lease Amendment") for the property located at 4 Hartwell Place in Lexington, Massachusetts. The only change to the terms of the lease was to increase the base rent by $ 0.1 million per year. There were no initial direct costs incurred, incremental incentives received or any other payments made to or by the Company with respect to the Master Lease Amendment. The Company accounted for the changes made to the lease agreement as a lease modification. The Company determined that the associated lease should continue to be accounted for as an operating lease with a lease term commensurate with the initial lease term, which ends in December 2029. The Company remeasured the lease liability as of November 15, 2021, based on the then-current applicable incremental borrowing rate resulting in an increase of $ 1.0 million, which was offset by an equal adjustment made to the corresponding right-of-use asset. 35 CambridgePark Drive On March 22, 2019, the Company entered into a non-cancelable property lease for its corporate headquarters, which included office and laboratory space at 35 CambridgePark Drive in Cambridge, Massachusetts. Under the terms of the lease, the Company leases 68,258 square feet for $ 4.9 million per year in base rent, which is subject to a 3.0 % annual rent increase during the initial lease term, plus certain operating expenses and taxes. The Company accounts for this lease as an operating lease. The lease term commenced on March 26, 2019 and is expected to end in November 2029 . The Company has the option to extend the lease for a 10-year period on the same terms and conditions as the current lease, subject to a change in base rent based on market rates . The Company occupied the space in February 2020 as its new corporate headquarters. Upon execution of the lease agreement, the Company provided a security deposit of $ 3.7 million, which is held in the form of a letter of credit and was classified as non-current restricted cash as of September 30, 2022 and December 31, 2021. The lease provides the Company with a tenant improvement allowance of $ 12.3 million, subject to reduction for a 2.0 % construction oversight fee due to the landlord, which is being amortized as a reduction to rent expense over the remaining lease term. The Company has received all $ 12.3 million of the tenant improvement allowance. Costs incurred related to the allowance are capitalized as leasehold improvements. Subleases 4 Hartwell Place On November 15, 2021 , the Company entered into a sublease agreement with Lonza for the entirety of its leased space at 4 Hartwell Place in Lexington, Massachusetts. Under the terms of the Sublease Agreement, Lonza is obligated to pay the Company base rent of $ 1.0 million per year, subject to a 2.8 % annual increase, plus certain operating expenses and other costs. The initial lease term commenced on November 15, 2021 and continues through November 30, 2024 . Lonza has the option to extend the sublease term for five 12-month periods on the same terms and conditions as the current sublease, subject to an increase of 2.8 % in the annual fixed rent charges. Additionally, Lonza has the right to have the associated master lease assigned to it beginning on January 1, 2026, subject to the landlord’s consent. As of September 30, 20 22, the Company has not been legally released from its primary obligations under the original lease. Therefore, the Company continues to account for the original lease as it did before commencement of the sublease, inclusive of the effects of the Master Lease Amendment. The Company determined that the sublease term is commensurate with the initial sublease term because it is not reasonably certain that any of the extension options will be exercised. 35 CambridgePark Drive On April 27, 2020, the Company entered into a sublease for 23,280 square feet of its leased space at 35 CambridgePark Drive. Under the terms of the sublease, the sublessee was to pay the Company $ 1.3 million per year, which was subject to a 3.0 % annual rent increase, plus certain operating expenses. The lease term commenced on May 18, 2020 and was expected to end in May 2022 . Effective July 1, 2021, the sublessee exercised its option to extend the sublease for a one-year period through May 2023 , on the same terms and conditions as the original sublease, subject to a change in base rent based on the greater of (i) an increase of 3.0 % of the annual rent owed by the sublessee in year two, and (ii) market rent for the subleased premises . Upon execution of the sublease agreement, the sublessee provided the Company a security deposit of $ 0.3 million, which is held in the form of a letter of credit. In July 2022, the sublessee defaulted on its lease payments. The Company and the sublessee mutually agreed to terminate the sublease effective September 16, 2022. The Company claimed the $ 0.3 million security deposit and wrote off lease assets of $ 0.4 million, which was recorded in other income. The Company is currently marketing the sublease to new tenants. During the three and nine months ended September 30, 2022, the Company recognized sublease income of $ 0.4 million and $ 2.1 million, respectively, which was recorded in other income. During the three and nine months ended September 30, 2021, the Company recognized sublease income of $ 0.5 million and $ 1.2 million, respectively, which was recorded in other income. The components of operating lease costs were as follows (in thousands): FOR THE THREE MONTHS ENDED SEPTEMBER 30, FOR THE NINE MONTHS ENDED SEPTEMBER 30, 2022 2021 2022 2021 Operating lease costs $ 1,240 $ 1,208 $ 3,720 $ 3,626 Short-term lease costs 5 8 12 21 Variable lease costs 712 638 2,026 1,897 Sublease income ( 430 ) ( 484 ) ( 2,102 ) ( 1,188 ) $ 1,527 $ 1,370 $ 3,656 $ 4,356 Variable lease costs were primarily related to operating expenses, taxes and utilities associated with the operating leases, which were assessed based on the Company’s proportionate share of such costs for the leased premises. Additional lease information is summarized in the following table (in thousands, except lease term and discount rate): FOR THE NINE MONTHS ENDED SEPTEMBER 30, 2022 2021 Cash paid for amounts included in the measurement of operating $ 4,700 $ 4,500 Weighted-average remaining lease term - operating leases (years) 7.2 8.2 Weighted-average discount rate - operating leases 10.1 % 10.3 % Undiscounted cash flows used in calculating the Company’s operating lease liabilities and amounts to be received under the sublease at 4 Hartwell Place as of September 30, 2022 are as follows (in thousands): Fiscal Year OPERATING SUBLEASE NET 2022 (remainder of the year) $ 1,573 $ 250 $ 1,323 2023 6,436 1,024 5,412 2024 6,625 965 5,660 2025 6,820 — 6,820 2026 7,020 — 7,020 Thereafter 21,779 — 21,779 Total undiscounted cash flows $ 50,253 $ 2,239 $ 48,014 Less: Amounts representing interest ( 14,669 ) Present value of lease liabilities $ 35,584

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2022
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	7. Commitments and contingencies Manufacturing Services Agreement The Company and Lonza entered into a MSA, which became effective on November 15, 2021. The MSA outlines the terms and conditions under which Lonza will develop, manufacture and supply exosome products for development and clinical purposes. The parties will negotiate and execute an amendment to the MSA to address the commercial manufacture of the Company’s exosome products. Each individual project to be completed under the MSA is governed by an associated statement of work which sets forth the activities to be performed, timeline, charges and payment schedule applicable to such project. Pricing is established on a project-by-project basis. Statements of work are executed between the parties on an as-requested basis. Activities had commenced with respect to outstanding statements of work as of September 30, 2022. The Company is subject to certain cancellation fees and/or other charges upon its termination of statements of work and in the event of a suspension or delay in the conduct of statements of work, including with respect to the reimbursement of non-cancelable costs incurred by Lonza. As of September 30, 2022, the Company has no t incurred any cancellation fees or other charges relating to a termination, suspension or delay of outstanding statements of work. Under the terms of the MSA, the Company is obligated to purchase the entirety of its aggregate production needs from Lonza, subject to limited exceptions. Starting on July 1, 2022, the Company was initially scheduled to provide to Lonza rolling forecasts of its anticipated manufacturing time requirements for the next 24 months from the date of the forecast, which will be updated no less frequently than quarterly. The delivery of rolling forecasts was postponed to September 2022, as agreed to by Lonza and the Company and the initial forecast has been provided to Lonza as of September 30, 2022. The first 12 months of each forecast will be a binding commitment, while the remaining 12 months will be non-binding. Commencing on January 1, 2026, the Company is bound by a commitment to purchase from Lonza a minimum of a specified number of weeks of manufacturing time each year at a predetermined price throughout the term of the arrangement. The Company’s minimum purchase commitments under the MSA may be relieved at its option upon the occurrence and during the pendency of certain liquidation events or clinical discontinuation s. As of September 30, 2022, the Company did no t have any minimum non-cancelable purchase obligations under the MSA. Pursuant to the terms of the MSA, the Company is entitled to a specified number of weeks of manufacturing time and a defined number of technology transfers from Lonza at no cost, with the exception of any accompanying materials costs, external costs and a handling fee. Additionally, the terms of the MSA provide the Company with a specified number of weeks of manufacturing time from Lonza at a discounted rate, subject to annual adjustment. The Company bears the expense associated with any materials costs, external costs and a handling fee related to the discounted manufacturing time. Manufacturing services in excess of the free and discounted time are priced at a fixed weekly rate, plus materials costs, external costs and a handling fee. The Company’s consumption of the free and discounted manufacturing time, including the associated technology transfer services, is subject to a contractually-specified apportionment by year, which commenced in 2022 and continues through 2025. The Company’s failure to use the free and discounted manufacturing time within the assigned period results in its forfeiture unless such inability is not due to the Company or Lonza permits carryover to a subsequent period. The Company has utilized $ 0.5 million of the manufacturing services for preliminary work as of September 30, 2022, which is recorded as research and development expenses. During the three and nine months ended September 30, 2022, the Company mutually agreed with Lonza to not utilize a portion of prepaid manufacturing services under the MSA in 2022. As the services were not being utilized, the Company recognized an impairment charge to the prepaid manufacturing services asset of $ 4.5 million, which is recorded within operating expenses. Unless earlier terminated or extended by the parties, the MSA remains in effect until the earlier of the: (i) fifth anniversary of the first approval of a biologics license application by the FDA for any of the Company’s exosome products or (ii) tenth anniversary of Lonza’s completion of the services associated with the free manufacturing time. The MSA is subject to customary termination provisions. Additionally, Lonza may terminate the MSA with 12 months ' advance notice for any or no reason at any time after November 15, 2023. To the extent the MSA is terminated on or prior to December 31, 2025, certain aspects of the transactions consummated in connection with the Lonza Transfer Transaction will be reverted, including with respect to assets, properties and rights that were transferred to Lonza effective on November 15, 2021. Lonza has the right to cease manufacturing under the MSA upon either: (i) the Company unreasonably withholding, conditioning or delaying its approval of certain price changes or (ii) the Company enduring certain liquidation events or clinical discontinuations. Any termination of the MSA for any reason will be without prejudice to any rights that will have accrued to the benefit of a party prior to such termination. Purchase orders The Company has agreements with third parties for various services, including services related to clinical and preclinical operations and support, for which the Company is not contractually able to terminate for convenience to avoid future obligations to the vendors. Certain agreements provide for termination rights subject to termination fees or wind down costs. Under such agreements, the Company is contractually obligated to make certain payments to vendors, primarily to reimburse them for their unrecoverable outlays incurred prior to cancelation. The actual amounts the Company could pay in the future to the vendors under such agreements may differ from the purchase order amounts due to cancellation provisions. Indemnification agreements The Company enters into standard indemnification agreements and/or indemnification sections in other agreements in the ordinary course of business. Pursuant to the agreements, the Company indemnifies, holds harmless, and agrees to reimburse the indemnified party for losses suffered or incurred by the indemnified party, generally the Company’s business partners. The term of these indemnification agreements is generally perpetual any time after execution of the agreement. The maximum potential amount of future payments the Company could be required to make under these indemnification agreements is unlimited. The Company has never incurred costs to defend lawsuits or settle claims related to these indemnification agreements. The Company does not believe that the outcome of any existing claims under indemnification arrangements will have a material impact on its financial statements, and it had not accrued any liabilities related to such obligations as of September 30, 2022 or December 31, 2021. Legal proceedings The Company is not currently party to any material legal proceedings. At each reporting date, the Company evaluates whether or not a potential loss amount or a potential range of loss is probable and reasonably estimable under the provisions of FASB ASC Topic 450, Contingencies . The Company expenses costs related to its legal proceedings as incurred.

Indebtedness

Indebtedness	9 Months Ended
	Sep. 30, 2022
Debt Disclosure [Abstract]
Indebtedness	8. Indebtedness On September 30, 2019 (the "Hercules Closing Date"), the Company entered into a loan and security agreement (the "Loan Agreement") with Hercules pursuant to which a term loan in an aggregate principal amount of up to $ 75.0 million (the "Term Loan Facility") was available to the Company in four tranches, subject to certain terms and conditions. On the Hercules Closing Date, $ 10.0 million of the first tranche was advanced to the Company and an additional $ 15.0 million under the first tranche was drawn down on July 24, 2020. Under the Loan Agreement, there were three additional tranches available to the Company of $ 10.0 million ("tranche two"), $ 10.0 million ("tranche three"), and $ 30.0 million ("tranche four"). As of September 30, 2022, tranches two, three and four had expired. Upon issuance, the initial advance under the first tranche was recorded as a liability with an initial carrying value of $ 9.5 million, net of debt issuance costs. The July 24, 2020 advance under the first tranche was recorded as a liability with an initial carrying value of $ 15.0 million. The initial carrying value of all outstanding advances is accreted to the repayment amount, which includes the outstanding principal plus the end of term charge, through interest expense using the effective interest rate method over the term of the loan. Effective September 17, 2021 (the "Amended Closing Date"), the Company amended the Loan Agreement with Hercules (the "Amended Loan Agreement"), increasing aggregate principal amount available from $ 75.0 million under the Term Loan Facility to $ 85.0 million (the "Amended Term Loan Facility"). Under the Amended Term Loan Facility, a new tranche three of $ 10.0 million was established and was available through December 15, 2021. Tranche four was amended such that $ 30.0 million is now available through the interest only period, subject to future lender investment committee approval. Tranche five of up to $ 20.0 million was established under the Amended Loan Agreement and is available through September 30, 2023, upon satisfaction of certain clinical milestones. Tranche five is only available in minimum draws of $ 5.0 million. Advances under the Amended Term Loan Facility bear interest at a rate equal to the greater of (i) 8.25 % plus the Prime Rate (as reported in The Wall Street Journal ) less 3.25 %, and (ii) 8.25 %. The interest only period under the Term Loan Facility was extended from November 1, 2022 to October 1, 2023 under the Amended Term Loan Facility and is further extendable to October 1, 2024 upon the achievement of certain clinical milestones. Under the Amended Term Loan Facility, following the interest only period, the Company will repay the principal balance and interest on the advances in equal monthly installments through October 1, 2025 , compared to October 1, 2024 under the Term Loan Facility. Prepayments on the Amended Loan Agreement, in whole or in part, at any time are subject to a prepayment charge (Prepayment Premium) equal to: (i) 2.0 % of amounts so prepaid, if such prepayment occurs during the first year following the Amended Closing Date, (ii) 1.5 % of the amount so prepaid, if such prepayment occurs during the second year following the Amended Closing Date, or (iii) 1.0 % of the amount so prepaid, if such prepayment occurs after the second year following the Amended Closing Date. Additionally, upon prepayment or repayment of all or any of the term loans under the Amended Term Loan Facility, the Company will pay an end of term charge of 5.5 % of the aggregate funded amount under the Term Loan Facility. The end of term charge of $ 1.4 million, or 5.6 % of the $ 25.0 million of principal advanced under the Term Loan Facility, remains payable at the maturity date under the original Term Loan Facility of October 1, 2024 . The terms under the Amended Loan Agreement were not substantially different from those under the original Loan Agreement, and the Amended Loan Agreement will be accounted for prospectively. The Amended Term Loan Facility remains secured by a lien on substantially all of the Company’s assets, other than the Company’s intellectual property. The Company has agreed not to pledge or grant a security interest on the Company’s intellectual property to any third party. The Amended Term Loan Facility also contains customary covenants and representations, including a liquidity covenant, whereby the Company is obligated to maintain, in an account covered by Hercules’ account control agreement, an amount equal to the lesser of: (i) 110 % of the amount of the Company’s obligations under the Amended Term Loan Facility, and (ii) the Company’s then-existing cash and cash equivalents, financial reporting covenant and limitations on dividends, indebtedness, collateral, investments, distributions, transfers, mergers or acquisitions, taxes, corporate changes, deposit accounts, and subsidiaries. The events of default under the Amended Loan Agreement include, without limitation, and subject to customary grace periods, the following: (i) any failure by the Company to make any payments of principal or interest under the Amended Loan Agreement, (ii) any breach or default in the performance of any covenant under the Amended Loan Agreement, (iii) the occurrence of a material adverse effect, (iv) any making of false or misleading representations or warranties in any material respect, (v) the Company’s insolvency or bankruptcy, (vi) certain attachments or judgments on the assets of the Company, or (vii) the occurrence of any material default under certain agreements or obligations of the Company’s involving indebtedness. If an event of default occurs, Hercules is entitled to take enforcement action, including acceleration of amounts due under the Amended Loan Agreement. As of September 30, 2022 and December 31, 2021, the carrying value of the Term Loan Facility was $ 25.7 million and $ 25.4 million, respectively, which was classified as a long-term liability. The fair value of debt was classified as Level 2 for the periods presented and approximates its carrying value due to the variable interest rate. The future principal payments under the Amended Loan Agreement are as follows as of September 30, 2022 (in thousands): Fiscal Year PRINCIPAL 2022 $ — 2023 2,694 2024 11,559 2025 10,747 $ 25,000 During the three months ended September 30, 2022 and 2021, the Company recognized $ 0.8 million and $ 0.7 million of interest expense related to the Amended Loan Agreement, respectively. During the nine months ended September 30, 2022 and 2021, the Company recognized $ 2.0 million and $ 2.1 million of interest expense related to the Amended Loan Agreement, respectively.

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 30, 2022
Share-Based Payment Arrangement, Additional Disclosure [Abstract]
Stock-Based Compensation	9. Stock-Based Compensation 2020 Stock Option and Incentive Plan The 2020 Stock Option and Incentive Plan (the "2020 Plan") became effective in October 2020. The 2020 Plan provides for the grant of incentive stock options, non-statutory stock options, stock appreciation rights, restricted stock awards, restricted stock units, and other stock-based awards. The number of shares of the Company’s common stock initially reserved for issuance under the 2020 Plan was 1,043,402 shares. The number of shares reserved annually increase on the first day of each calendar year, beginning on January 1, 2021 and ending on and including January 1, 2030, equal to the lesser of 5 % of the number of shares of common stock outstanding on the final day of the immediately preceding calendar year or such lesser number of shares determined by the compensation committee. As of January 1, 2022, 1,119,192 additional shares of common stock were reserved for issuance under the 2020 Plan. The shares of the Company’s common stock subject to outstanding awards under the 2015 Stock Option and Grant Plan that expire, terminate or are otherwise surrendered, cancelled, forfeited or repurchased by the Company at their original issuance price pursuant to a contractual repurchase right will be added back to the shares of common stock available for issuance under the 2020 Plan. As of September 30, 2022 , there were 501,018 shares available for future issuance under the 2020 Plan. The Company’s stock options expire after approximately ten years from the date of grant. As of September 30, 2022 , the Company does no t hold any treasury shares. Upon stock option exercise, the Company issues new shares and delivers them to the participant. 2020 Employee Stock Purchase Plan The Company’s 2020 Employee Stock Purchase Plan, (the "ESPP") was adopted by the Company's board of directors, approved by the Company’s stockholders and became effective in October 2020. The ESPP initially provides participating employees with the opportunity to purchase up to an aggregate of 208,680 shares of the Company’s common stock. The number of shares of common stock reserved for issuance under the ESPP may be increased on the first day of each calendar year, beginning on January 1, 2021 and ending on January 1, 2030, by the lesser of (i) 834,720 shares of common stock, (ii) 0.5 % of the outstanding shares of common stock on the immediately preceding December 31 and (iii) such lesser number of shares as determined by the administrator of the ESPP. There had been no increase in the number of shares of common stock reserved for issuance under the ESPP as of September 30, 2022. Stock Options The following table summarizes the Company’s option activity during the nine months ended September 30, 2022: NUMBER WEIGHTED WEIGHTED AGGREGATE (In years) (In thousands) Outstanding as of December 31, 2021 4,763,489 $ 12.56 6.44 $ 10,370 Granted 1,253,675 5.74 Exercised — — Forfeited/Cancelled ( 796,424 ) 13.44 Outstanding as of September 30, 2022 5,220,740 $ 10.79 5.98 $ — Exercisable as of September 30, 2022 3,166,270 $ 10.08 4.53 $ — Vested and expected to vest as of September 30, 2022 5,220,740 $ 10.79 5.98 $ — (1) Aggregate intrinsic value is calculated as the difference between the exercise price of the underlying options and the fair value of common stock for those stock options that had exercise prices lower than the fair value of the Company’s common stock as of September 30, 2022 and December 31, 2021 . The aggregate intrinsic value of stock options exercised during the three months ended September 30, 2022 and 2021 was $ 0.0 million and $ 0.8 million, respectively. The aggregate intrinsic value of stock options exercised during the nine months ended September 30, 2022 and 2021 was $ 0.0 million and $ 5.1 million, respectively. Restricted Stock Units The following table summarizes the Company’s restricted stock unit activity during the nine months ended September 30, 2022: NUMBER WEIGHTED Outstanding as of December 31, 2021 — $ — Granted 1,896,683 3.21 Vested ( 130,164 ) 5.18 Forfeited/Cancelled ( 162,408 ) 5.86 Outstanding as of September 30, 2022 1,604,111 $ 0.74 Vested and expected to vest as of September 30, 2022 1,604,111 $ 0.74 Stock-Based Compensation Expense The following table presents the components and classification of stock-based compensation expense (in thousands): THREE MONTHS ENDED NINE MONTHS ENDED 2022 2021 2022 2021 Research and development $ 1,121 $ 1,646 $ 3,262 $ 3,925 General and administrative 1,166 1,446 4,042 4,130 $ 2,287 $ 3,092 $ 7,304 $ 8,055 Employee $ 2,143 $ 3,049 $ 6,599 $ 7,908 Non-employee 144 43 705 147 $ 2,287 $ 3,092 $ 7,304 $ 8,055 As of September 30, 2022, the total unrecognized compensation expense related to the Company’s stock compensation awards w as $ 16.4 million, which the Company expects to recognize over a weighted-average period of approximately 2.3 years.

Collaborative Arrangements

Collaborative Arrangements	9 Months Ended
	Sep. 30, 2022
Collaboration Agreements [Abstract]
Collaborative Arrangements	10. Collaboration agreements Detailed description of contractual terms and the Company’s accounting for agreements described below were included in the Company’s audited financial statements and notes in the 2021 Annual Report. The following table summarizes our total consolidated revenue from our current and former strategic collaborators for the periods presented (in thousands): THREE MONTHS ENDED NINE MONTHS ENDED Collaboration Revenue by Strategic Collaborator: 2022 2021 2022 2021 Jazz $ 28 $ 118 $ 26,044 $ 11,225 Sarepta — 1,039 ( 167 ) 4,013 Total collaboration revenue $ 28 $ 1,157 $ 25,877 $ 15,238 The following tables present changes in the Company’s contract assets and liabilities for the period presented (in thousands): NINE MONTHS ENDED SEPTEMBER 30, 2022 BALANCE ADDITIONS DEDUCTIONS BALANCE Contract assets: Account receivable (1) $ 628 — ( 628 ) $ — Contract liabilities: Deferred revenue $ 43,649 — ( 26,044 ) $ 17,605 (1) Included in prepaid expenses and other current assets as shown within the condensed consolidated balance sheets. During the three and nine months ended September 30, 2022 and 2021, the Company recognized the following revenue (in thousands): THREE MONTHS ENDED SEPTEMBER 30, NINE MONTHS ENDED 2022 2021 2022 2021 Revenue recognized in the period from: Amounts included in deferred revenue at the beginning of the period $ 28 $ 1,157 $ 26,044 $ 15,238 Jazz collaboration and license agreement During the three and nine months ended September 30, 2022, the Company continued to perform under its Collaboration and License Agreement (the "Jazz Collaboration Agreement"), pursuant to which the Company recognizes revenues utilizing the cost-based input method. As a result, the Company recognizes over time as revenue the transaction price allocated to each performance obligation as research and development services are performed. The following table summarizes research and development costs incurred and revenue recognized in connection with Company's performance under the Jazz Collaboration Agreement (in thousands): THREE MONTHS ENDED NINE MONTHS ENDED 2022 2021 2022 2021 Revenue recognized $ 28 $ 118 $ 26,044 $ 11,225 Costs incurred $ 226 $ 606 $ 1,178 $ 1,947 Four of the targets were identified at the inception of the collaboration (the "Initial Collaboration Targets"). In April 2021, the Company and Jazz mutually agreed to discontinue their work on exoASO-STAT3 ("STAT3"), one of the five oncogene targets subject to the Jazz Collaboration Agreement. The Company recognized the remaining $ 10.9 million in deferred revenue allocated to this target during the nine months ended September 30, 2021. On June 30, 2021, Jazz formally nominated the fifth collaboration target. The Company will recognize the $ 2.8 million of revenue allocated to this performance obligation consistent with all active Jazz targets, recording revenue based on actual costs incurred relative to the budgeted costs to complete each of the respective programs. In January 2022, the Company and Jazz mutually agreed to discontinue their work on NRAS. The Company recognized the remaining $ 12.6 million in deferred revenue allocated to this target during the three months ended March 31, 2022. In July 2022, the Company and Jazz mutually agreed to discontinue their work on an undisclosed third target, and the Company recognized the remaining $ 13.3 million in deferred revenue allocated to this target during the three months ended June 30, 2022, as the preclinical activities that informed this decision were completed prior to the end of the period. For the nine months ended September 30, 2022, the Company recognized a combined $ 26.0 million in deferred revenue primarily allocated to NRAS and an undisclosed third target, two of the five oncogene targets subject to the Jazz Collaboration Agreement. As of September 30, 2022, except for the decision relating to NRAS and the undisclosed third target, there were no significant changes in the Company's assumptions or estimates related to the costs to complete development. Jazz also has the option to nominate an additional target (a "Replacement Target") if two of the Initial Collaboration Targets fail prior to acceptance of an Investigational New Drug application ("IND"). As of September 30, 2022, there are three remaining material rights outstanding under the Jazz Collaboration Agreement Codiak and Jazz continue to jointly advance their research and development efforts on other exosome-based therapeutic programs to treat cancer pursuant to the Jazz Collaboration Agreement. Jazz has the contractual right to revive terminated targets as active targets in the future. There have been no changes to the Company’s estimate of variable consideration on active performance obligations since inception of the arrangement through September 30, 2022. As of September 30, 2022, the Company has not achieved any preclinical development, IND acceptance, clinical, regulatory or sales milestones or earned any royalties or profit share under the Jazz Collaboration Agreement. As of September 30, 2022 and December 31, 2021, the Comp any had $ 17.6 million and $ 43.6 million, respectively, of deferred revenue related to the Company’s collaboration with Jazz, which is classified as current or long-term in the accompanying consolidated balance sheet based on the expected timing of recognizing such amounts as revenue. Sarepta license and option agreement On October 1, 2021, Sarepta notified the Company that it was terminating early the research license and option agreement (the "Sarepta Research Agreement"). The termination was effective as of December 3, 2021 . As a result of the termination, each of the license and options granted to Sarepta were terminated in their entirety, and the Company regained all rights previously granted to Sarepta. During the nine months ended September 30, 2022, the Company was no longer obligated to perform under its Sarepta Research Agreement, pursuant to which the Company recognized revenue utilizing the cost-based input method. The Company recognized contract to date revenue of $ 13.9 million as research and development services that were performed through December 3, 2021. During the nine months ended September 30, 2022, the Company collected on a receivable for services performed under the Sarepta Research Agreement, which was held at $ 0.6 million at January 1, 2022. The transaction price related to such services was subsequently revised during the period, which resulted in a reduction to revenue. The following table summarizes research and development costs incurred and revenue recognized in connection with Company's performance under the Sarepta Research Agreement (in thousands): THREE MONTHS ENDED NINE MONTHS ENDED 2022 2021 2022 2021 Revenue recognized $ — $ 1,039 $ ( 167 ) $ 4,013 Costs incurred $ — $ 1,039 $ — $ 4,013

Other Significant Agreements

Other Significant Agreements	9 Months Ended
	Sep. 30, 2022
Significant Agreements [Abstract]
Other Significant Agreements	11. Other significant agreements MDACC in-license agreement In November 2015, the Company entered into a patent and technology license agreement with MDACC, as amended in April 2018 (the "MDACC License Agreement"). Pursuant to the MDACC License Agreement, the Company holds exclusive worldwide license rights to certain intellectual property relating to the use of exosomes for diagnostic and therapeutic applications and a non-exclusive worldwide license under certain related technologies, with the right to grant sublicenses. The Company also obtained the exclusive right of first negotiation, for a specified time period, for a license to certain of MDACC’s rights in future exosome technology. Under the terms of the MDACC License Agreement, the Company is responsible for all patent costs incurred by MDACC for the underlying licensed technology in excess of $ 1.5 million from the effective date of the agreement through February 1, 2021, and for all patent costs incurred or invoiced after this date. As of September 30, 2022 , there was no remaining funding provided by MDACC for patent-related costs under the MDACC License Agreement. Pursuant to the MDACC License Agreement, the Company is also required to make future payments to MDACC upon the occurrence of events related to the development of products and upon the achievement of certain development and regulatory approval milestones up to an aggregate of $ 11.9 million, comprising up to $ 2.4 million for diagnostic products and up to $ 9.5 million for therapeutic products. The Company may at its discretion pay up to $ 4.4 million in such contingent payments in cash or through the issuance of equity in the form of redeemable convertible preferred stock or common stock, as applicable. Such payments will be expensed or capitalized based on the nature of the associated asset at the date the related contingency is resolved. In addition, the Company is obligated to pay certain payments upon the execution of sublicenses for qualifying products, as well as single digit percentage royalty payments on net sales from a licensed product. The MDACC License Agreement will continue until the last to occur of: (i) the expiration of all patents issued underlying the licenses conveyed, (ii) the cancellation, withdrawal or express abandonment of all patent rights underlying the licenses conveyed, and (iii) the fifteenth anniversary of the effective date of the agreement. Upon expiration of the MDACC License Agreement, the licenses granted will automatically convert to a fully-paid irrevocable and perpetual license. The Company may terminate the license for convenience upon 180 days ' prior written notice to MDACC. The license automatically terminates upon the Company’s bankruptcy, if the Company challenges the validity or enforceability of any of the licensed patent rights, or if the Company fails to make a number of payments in a timely manner over a specified period of time. Additionally, MDACC may terminate the license for the Company’s breach subject to certain specified cure periods. As of September 30, 2022 , no milestones had been achieved, nor had any royalties, sublicensing fees or other contingent payments been incurred under the MDACC License Agreement. The Company did no t make any payments to MDACC for the three and nine months ended September 30, 2022 and 2021 with respect to the MDACC License Agreement. Kayla Therapeutics S.A.S license agreement On November 6, 2018, the Company entered into a license agreement with Kayla, pursuant to which it obtained a co-exclusive worldwide, sublicensable license under certain patent rights and to related know-how and methods to research, develop, manufacture and commercialize compounds and products covered by such patent rights in all diagnostic, prophylactic and therapeutic uses (the "Kayla License Agreement"). The foregoing license is co-exclusive with Kayla, but Kayla’s retained rights are subject to certain restrictions. During the first six years following the effective date of the Kayla License Agreement, Kayla and its affiliates may not research, develop, manufacture or commercialize anywhere in the world any product containing a small molecule STING agonist and an exosome. In addition, during the term of the Kayla License Agreement, Kayla and its affiliates may not grant a license to any third party under the licensed patent rights to, develop, manufacture or commercialize anywhere in the world a product containing certain STING compounds for therapeutic or veterinary purpose. The Kayla License Agreement also restricts the Company from developing any competing product containing a small molecule STING agonist and an exosome until the expiration of a non-compete period determined by the achievement of clinical milestones. The Company has certain diligence obligations under the Kayla License Agreement, which include using commercially reasonable efforts to develop, commercialize and market the products developed under the licensed patent rights, including using commercially reasonable efforts to initiate a cohort extension of a Phase 1/2 trial after obtaining IND approval. The Company is also obligated to pay up to $ 100.0 million in cash payments and up to $ 13.0 million payable in shares of the Company’s common stock upon the achievement of specified clinical and regulatory milestones, including approvals in the U.S., the EU and Japan. Such payments will be expensed or capitalized based on the nature of the associated asset at the date the related contingency is resolved. Additionally, the Company is obligated to pay to Kayla a percentage of the payments that the Company receives from sublicensees of the rights licensed to it by Kayla, excluding any royalties. This percentage varies from single digits to low double digits. The first milestone was achieved upon the dosing of the first subject in the Company’s exoSTING Phase 1/2 clinical trial in September 2020. Upon achievement of the milestone, the Company was obligated to make a nonrefundable payment of $ 15.0 million in cash and issue 177,318 shares of common stock to Kayla. The common stock was issued as of the date of dosing, and the cash payment of $ 15.0 million was paid as of December 31, 2020. As of September 30, 2022 , no other milestones had been achieved. The Company is obligated to pay to Kayla tiered royalties ranging from low single-digits to mid-single-digits based on annual net sales by the Company, its affiliates and its sublicensees of licensed products. The royalty term is determined on a product-by-product and country-by-country basis and continues until the later of (i) the expiration of the last valid claim of the licensed patent rights that covers such product in such country, (ii) the loss or expiration of any period of marketing exclusivity for such product in such country, and (iii) ten years after the first commercial sale of such product in such country; provided that if the royalty is payable when no valid claim covers a given product in a given country, the royalty rate for sales of such product in such country is decreased. The Company may terminate the Kayla License Agreement on a licensed compound-by-licensed compound basis and on a region-by region basis for any reason upon 30 days ' prior written notice to Kayla. The Company or Kayla may terminate the Kayla License Agreement for the other’s material breach that remains uncured for 60 days after receiving notice thereof. As of September 30, 2022 , no royalties, or other contingent payments had been incurred under the Kayla License Agreement.

Grant Revenue

Grant Revenue	9 Months Ended
	Sep. 30, 2022
Revenue from Contract with Customer [Abstract]
Grant Revenue	12. Grant revenue In July 2022, the Company entered into a new partnership with CEPI to advance our exoVACC pan betacoronavirus program. As part of the partnership, CEPI is providing seed funding of up to $ 2.5 million, which the Company anticipates will fund the completion of preclinical development and identification of a clinical candidate by early 2023. All funding received from CEPI must be used for preclinical studies, assessing the immune response against known Betacoronaviruses that already pose a significant epidemic or pandemic risk, such as SARS-CoV-1, SARS-CoV-2, and MERS-CoV, and the potential of the immune response to protect against infection and disease caused by these viruses. As of September 30, 2022, the Company has received $ 1.6 million in grants. During both the three and nine months ended September 30, 2022, the Company recognized $ 0.5 million in grant revenue under its partnership with CEPI. As of September 30, 2022, the Company had $ 1.1 million in deferred revenue with respect to its partnership with CEPI.

Restructuring

Restructuring	9 Months Ended
	Sep. 30, 2022
Restructuring and Related Activities [Abstract]
Restructuring	13. Restructuring In August 2022, the board of directors of the Company approved a reduction of the Company’s workforce by approximately 37 % across all areas of the Company. This workforce reduction was completed as of September 30, 2022. These actions reflect the reprioritization of its clinical and research initiatives. The Company has paused plans to initiate Phase 2 trials of exoSTING and exoIL-12 while prioritizing its Phase 1 clinical trial of exoASO-STAT6. During each of the three and nine months ended September 30, 2022, the Company recognized $ 0.7 million of restructuring charges in the condensed consolidated statement of operations. These charges included $ 0.5 million of one-time termination benefits and contractual termination benefits for severance, healthcare, and related benefits and $ 0.2 million of non-cash stock-based compensation expense. The Company recorded $ 0.5 million and $ 0.2 million in research and development expenses and general and administrative expenses, respectively. Details of the restructuring liability activity for the Company's workforce reduction for the period ended September 30, 2022 are as follows: September 30, 2022 (in thousands) Balance at December 31, 2021 $ — Restructuring charges 651 Severance payments ( 329 ) Stock-based compensation expense ( 151 ) Balance at September 30, 2022 $ 171

Net Loss Per Share

Net Loss Per Share	9 Months Ended
	Sep. 30, 2022
Earnings Per Share [Abstract]
Net Loss Per Share	14. Net loss per share Basic and diluted net loss per share attributable to common stockholders was calculated as follows (in thousands, except share and per share data): THREE MONTHS ENDED NINE MONTHS ENDED 2022 2021 2022 2021 Numerator: Net loss $ ( 19,278 ) $ ( 21,702 ) $ ( 34,081 ) $ ( 53,819 ) Net loss attributable to common stockholders $ ( 19,278 ) $ ( 21,702 ) $ ( 34,081 ) $ ( 53,819 ) Denominator: Weighted average common shares outstanding, basic 25,159,757 22,325,334 23,373,684 21,599,405 Net loss per share attributable to common stockholders, $ ( 0.77 ) $ ( 0.97 ) $ ( 1.46 ) $ ( 2.49 ) The following common stock equivalents, presented based on amounts outstanding at each period end, were excluded from the calculation of diluted net loss per share attributable to common stockholders for the periods indicated because including them would have been anti-dilutive: THREE MONTHS ENDED SEPTEMBER 30, NINE MONTHS ENDED SEPTEMBER 30, 2022 2021 2022 2021 Restricted stock units 1,604,111 — 1,604,111 — Warrants 14,027,665 — 14,027,665 — Outstanding stock options 5,220,740 4,953,272 5,220,740 4,953,272 Outstanding awards 20,852,516 4,953,272 20,852,516 4,953,272

Summary of Basis of Presentat_2

Summary of Basis of Presentation and Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2022
Accounting Policies [Abstract]
Basis of Presentation and Principles of Consolidation	Basis of Presentation and Principles of Consolidation The consolidated financial statements include the Company and its subsidiaries. All intercompany transactions and balances have been eliminated in consolidation.
Use of Estimates	Use of Estimates We have made estimates and judgments affecting the amounts reported in our consolidated financial statements and the accompanying notes. On an ongoing basis, we evaluate our estimates, including critical accounting policies or estimates related to revenue recognition, stock-based compensation, accrued expenses, leases, gain upon derecognition, contingent consideration, prepaid manufacturing services, warrants and impairment assessments. We base our estimates on historical experience and various relevant assumptions that we believe to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. The actual results that we experience may differ materially from our estimates.
Accounting Pronouncements and Significant Accounting Policies	Accounting Pronouncements and Significant Accounting Policies The Company reviews new accounting standards as they are issued by the FASB or other standard-setting bodies. As of September 30, 2022, the Company has not identified any new standards that it believes will have a material impact on the Company’s financial statements. Restructuring The Company records costs and liabilities associated with exit and disposal activities based on estimates of fair value in the period in which the liabilities are incurred. The Company evaluates and adjusts these costs as appropriate for changes in circumstances as additional information becomes available. Restructuring costs comprise severance costs related to workforce reductions. When employees are not required to provide service beyond the minimum retention period, employee termination benefits are accrued at the date management has committed to a plan of termination and employees have been notified of their termination dates and expected severance payments. Grant Revenue The Company received a grant award from the Coalition for Epidemic Preparedness Innovations ("CEPI") for research and development related activities that provide for payments for qualifying costs, which may include overhead and general and administrative costs. We recognize revenue from this agreement as we perform services under the arrangement when the funding is committed and the costs are deemed to qualify pursuant to the grant. Associated expenses are recognized when incurred as research and development expenses. The services being rendered under this agreement are part of the Company's primary operations. Revenues and related expenses are presented gross in the consolidated statements of operations as we have determined we are the primary obligor under the arrangements relative to the research and development services we perform. Derivative Liability - Warrants In September 2022, the Company completed a follow-on offering of common stock. In connection with the follow-on offering, each share of common stock issued was accompanied by a warrant to purchase a single share of common stock. These warrants are derivative financial instruments under ASC Topic 815, Derivatives and Hedging (“ASC 815”) and do not qualify for the scope exceptions from derivative accounting. These derivatives are recorded as liabilities at fair value each reporting date and the fair value is determined using the Black-Scholes option-pricing model. The warrants are initially recorded as a reduction to proceeds from the common stock issuance in additional paid-in-capital. The changes in fair value are recorded as a component of other (expense) income in the consolidated statements of operations. Significant inputs used to determine the fair value at execution and as of September 30, 2022, included the price per share of the Company’s common stock, expected terms of the derivative instruments, strike price of the derivative instrument, risk-free interest rate, and expected volatility of peer company common stock. Changes to these inputs could materially affect the valuation of the warrants. There were no other changes to the Company’s significant accounting policies during the nine months ended September 30, 2022.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2022
Fair Value Disclosures [Abstract]
Assets and Liabilities Measured at Fair Value on a Recurring Basis	The following tables present information about the Company’s assets measured at fair value on a recurring basis, and indicate the level of the fair value hierarchy utilized to determine such fair values (in thousands): SEPTEMBER 30, 2022 TOTAL LEVEL 1 LEVEL 2 LEVEL 3 NOT Liabilities: Derivative liability – warrants $ 5,428 $ — $ — $ 5,428 $ — $ 5,428 $ — $ — $ 5,428 $ — DECEMBER 31, 2021 TOTAL LEVEL 1 LEVEL 2 LEVEL 3 NOT Assets: Cash equivalents: Money market funds $ 67,603 $ — $ — $ — $ 67,603 $ 67,603 $ — $ — $ — $ 67,603 (1) Certain cash equivalents that are valued using the net asset value per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy.
Schedule of Fair Market Valuation of Warrants	The following inputs were used in the fair market valuation of warrants as of September 30, 2022: September 30, 2022 Risk-free rate (1) 4.06 % Expected term 4.96 Stock price (2) $ 0.78 Strike price (3) $ 1.88 Common stock volatility (4) 79.93 % Dividend yield (5) — % (1) Based on the U.S. Treasury yield curve, with terms commensurate with the expected term of the warrants. (2) The closing price of the Company's common stock on the last trading day of the quarter ended September 30, 2022. (3) As per the agreement for the warrant. (4) Expected volatility based on historical volatility of the Company's peer companies that are commensurate with the expected term of the warrants. (5) The Company has not paid and does not anticipate paying cash dividends on its shares of common stock in the foreseeable future; therefore, the expected dividend yield is assumed to be zero.
Schedule of Change in Fair Value of Level 3 Warrants	The following table reflects the change in the Company's Level 3 warrants from December 31, 2021 through September 30, 2022 (in thousands): Warrants (in thousands) Balance at December 31, 2021 $ — Issuance fair value at September 15, 2022 8,150 Change in fair value, recorded as a gain on derivative liability - warrants ( 2,722 ) Balance at September 30, 2022 $ 5,428

Accrued Expenses (Tables)

Accrued Expenses (Tables)	9 Months Ended
	Sep. 30, 2022
Payables and Accruals [Abstract]
Schedule of Accrued Expenses	Accrued expenses consist of the following (in thousands): SEPTEMBER 30, DECEMBER 31, Employee compensation $ 4,266 $ 5,142 External research and development costs 2,045 2,420 Professional services and consulting 1,201 1,523 Facilities costs 263 190 Other expenditures 351 428 $ 8,126 $ 9,703

Leases (Tables)

Leases (Tables)	9 Months Ended
	Sep. 30, 2022
Leases [Abstract]
Components of Operating Lease Costs	The components of operating lease costs were as follows (in thousands): FOR THE THREE MONTHS ENDED SEPTEMBER 30, FOR THE NINE MONTHS ENDED SEPTEMBER 30, 2022 2021 2022 2021 Operating lease costs $ 1,240 $ 1,208 $ 3,720 $ 3,626 Short-term lease costs 5 8 12 21 Variable lease costs 712 638 2,026 1,897 Sublease income ( 430 ) ( 484 ) ( 2,102 ) ( 1,188 ) $ 1,527 $ 1,370 $ 3,656 $ 4,356
Summary of Additional Lease Information	Additional lease information is summarized in the following table (in thousands, except lease term and discount rate): FOR THE NINE MONTHS ENDED SEPTEMBER 30, 2022 2021 Cash paid for amounts included in the measurement of operating $ 4,700 $ 4,500 Weighted-average remaining lease term - operating leases (years) 7.2 8.2 Weighted-average discount rate - operating leases 10.1 % 10.3 %
Schedule of Undiscounted Cash Flows Used in Calculating the Operating Lease Liabilities and Amounts to be Received under the Sublease	Undiscounted cash flows used in calculating the Company’s operating lease liabilities and amounts to be received under the sublease at 4 Hartwell Place as of September 30, 2022 are as follows (in thousands): Fiscal Year OPERATING SUBLEASE NET 2022 (remainder of the year) $ 1,573 $ 250 $ 1,323 2023 6,436 1,024 5,412 2024 6,625 965 5,660 2025 6,820 — 6,820 2026 7,020 — 7,020 Thereafter 21,779 — 21,779 Total undiscounted cash flows $ 50,253 $ 2,239 $ 48,014 Less: Amounts representing interest ( 14,669 ) Present value of lease liabilities $ 35,584

Indebtedness (Tables)

Indebtedness (Tables)	9 Months Ended
	Sep. 30, 2022
Debt Disclosure [Abstract]
Schedule of Future Principal Payments	The future principal payments under the Amended Loan Agreement are as follows as of September 30, 2022 (in thousands): Fiscal Year PRINCIPAL 2022 $ — 2023 2,694 2024 11,559 2025 10,747 $ 25,000

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2022
Summary of Option Activity	The following table summarizes the Company’s option activity during the nine months ended September 30, 2022: NUMBER WEIGHTED WEIGHTED AGGREGATE (In years) (In thousands) Outstanding as of December 31, 2021 4,763,489 $ 12.56 6.44 $ 10,370 Granted 1,253,675 5.74 Exercised — — Forfeited/Cancelled ( 796,424 ) 13.44 Outstanding as of September 30, 2022 5,220,740 $ 10.79 5.98 $ — Exercisable as of September 30, 2022 3,166,270 $ 10.08 4.53 $ — Vested and expected to vest as of September 30, 2022 5,220,740 $ 10.79 5.98 $ — (1) Aggregate intrinsic value is calculated as the difference between the exercise price of the underlying options and the fair value of common stock for those stock options that had exercise prices lower than the fair value of the Company’s common stock as of September 30, 2022 and December 31, 2021 .
Summary of Restricted Stock Unit Activity	The following table summarizes the Company’s restricted stock unit activity during the nine months ended September 30, 2022: NUMBER WEIGHTED Outstanding as of December 31, 2021 — $ — Granted 1,896,683 3.21 Vested ( 130,164 ) 5.18 Forfeited/Cancelled ( 162,408 ) 5.86 Outstanding as of September 30, 2022 1,604,111 $ 0.74 Vested and expected to vest as of September 30, 2022 1,604,111 $ 0.74
Schedule of Components and Classification of Stock-Based Compensation Expense	The following table presents the components and classification of stock-based compensation expense (in thousands): THREE MONTHS ENDED NINE MONTHS ENDED 2022 2021 2022 2021 Research and development $ 1,121 $ 1,646 $ 3,262 $ 3,925 General and administrative 1,166 1,446 4,042 4,130 $ 2,287 $ 3,092 $ 7,304 $ 8,055 Employee $ 2,143 $ 3,049 $ 6,599 $ 7,908 Non-employee 144 43 705 147 $ 2,287 $ 3,092 $ 7,304 $ 8,055

Collaborative Arrangements (Tab

Collaborative Arrangements (Tables)	9 Months Ended
	Sep. 30, 2022
Summary of Total Consolidated Revenue from Strategic Collaborators	The following table summarizes our total consolidated revenue from our current and former strategic collaborators for the periods presented (in thousands): THREE MONTHS ENDED NINE MONTHS ENDED Collaboration Revenue by Strategic Collaborator: 2022 2021 2022 2021 Jazz $ 28 $ 118 $ 26,044 $ 11,225 Sarepta — 1,039 ( 167 ) 4,013 Total collaboration revenue $ 28 $ 1,157 $ 25,877 $ 15,238
Schedule of Changes in Contract Assets and Liabilities	The following tables present changes in the Company’s contract assets and liabilities for the period presented (in thousands): NINE MONTHS ENDED SEPTEMBER 30, 2022 BALANCE ADDITIONS DEDUCTIONS BALANCE Contract assets: Account receivable (1) $ 628 — ( 628 ) $ — Contract liabilities: Deferred revenue $ 43,649 — ( 26,044 ) $ 17,605 (1) Included in prepaid expenses and other current assets as shown within the condensed consolidated balance sheets.
Schedule of Revenue Recognized	During the three and nine months ended September 30, 2022 and 2021, the Company recognized the following revenue (in thousands): THREE MONTHS ENDED SEPTEMBER 30, NINE MONTHS ENDED 2022 2021 2022 2021 Revenue recognized in the period from: Amounts included in deferred revenue at the beginning of the period $ 28 $ 1,157 $ 26,044 $ 15,238
Jazz Pharmaceuticals Ireland Limited
Schedule of Research and Development Costs Incurred and Revenue Recognized	The following table summarizes research and development costs incurred and revenue recognized in connection with Company's performance under the Jazz Collaboration Agreement (in thousands): THREE MONTHS ENDED NINE MONTHS ENDED 2022 2021 2022 2021 Revenue recognized $ 28 $ 118 $ 26,044 $ 11,225 Costs incurred $ 226 $ 606 $ 1,178 $ 1,947
Sarepta Therapeutics
Schedule of Research and Development Costs Incurred and Revenue Recognized	The following table summarizes research and development costs incurred and revenue recognized in connection with Company's performance under the Sarepta Research Agreement (in thousands): THREE MONTHS ENDED NINE MONTHS ENDED 2022 2021 2022 2021 Revenue recognized $ — $ 1,039 $ ( 167 ) $ 4,013 Costs incurred $ — $ 1,039 $ — $ 4,013

Restructuring (Tables)

Restructuring (Tables)	9 Months Ended
	Sep. 30, 2022
Restructuring and Related Activities [Abstract]
Summary of restructuring liability activity	Details of the restructuring liability activity for the Company's workforce reduction for the period ended September 30, 2022 are as follows: September 30, 2022 (in thousands) Balance at December 31, 2021 $ — Restructuring charges 651 Severance payments ( 329 ) Stock-based compensation expense ( 151 ) Balance at September 30, 2022 $ 171

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	9 Months Ended
	Sep. 30, 2022
Earnings Per Share [Abstract]
Basic and Diluted Net Loss Per Share Attributable to Common Stockholders	Basic and diluted net loss per share attributable to common stockholders was calculated as follows (in thousands, except share and per share data): THREE MONTHS ENDED NINE MONTHS ENDED 2022 2021 2022 2021 Numerator: Net loss $ ( 19,278 ) $ ( 21,702 ) $ ( 34,081 ) $ ( 53,819 ) Net loss attributable to common stockholders $ ( 19,278 ) $ ( 21,702 ) $ ( 34,081 ) $ ( 53,819 ) Denominator: Weighted average common shares outstanding, basic 25,159,757 22,325,334 23,373,684 21,599,405 Net loss per share attributable to common stockholders, $ ( 0.77 ) $ ( 0.97 ) $ ( 1.46 ) $ ( 2.49 )
Anti-dilutive Securities Excluded from Calculation of Diluted Net Loss Per Share Attributable to Common Stockholders	The following common stock equivalents, presented based on amounts outstanding at each period end, were excluded from the calculation of diluted net loss per share attributable to common stockholders for the periods indicated because including them would have been anti-dilutive: THREE MONTHS ENDED SEPTEMBER 30, NINE MONTHS ENDED SEPTEMBER 30, 2022 2021 2022 2021 Restricted stock units 1,604,111 — 1,604,111 — Warrants 14,027,665 — 14,027,665 — Outstanding stock options 5,220,740 4,953,272 5,220,740 4,953,272 Outstanding awards 20,852,516 4,953,272 20,852,516 4,953,272

Nature of the Business - Additi

Nature of the Business - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands				9 Months Ended
	Sep. 15, 2022	Feb. 17, 2021	Oct. 16, 2020	Sep. 30, 2022	Sep. 30, 2021
Subsidiary, Sale of Stock [Line Items]
Entity date of incorporation				Jun. 12, 2015
Common stock, shares issued and sold	14,027,665	3,162,500	5,500,000
Purchase of warrants of common stock	14,027,665
Common stock, offering price	$ 1.50	$ 21	$ 15
Net proceeds from issuance of common stock	$ 19,800	$ 61,700	$ 74,400	$ 20,618	$ 61,681
Additional Common stock, shares issued	694,332	412,500
Additional purchase of warrants of common stock	694,332
Issuance of redeemable convertible preferred stock				168,200
Net of issuance costs				24,600
Payments from its collaborations				66,000
Cash and cash equivalents				$ 51,800
Substantial Doubt about Going Concern, within One Year [true false]				true
Substantial doubt about going concern, description				The Company has evaluated whether there are conditions and events, considered in the aggregate, that raise substantial doubt about its ability to continue as a going concern within one year after the date that the consolidated financial statements are issued.
At-The-Market Offering
Subsidiary, Sale of Stock [Line Items]
Common stock, shares issued and sold				236,303
Net proceeds from issuance of common stock				$ 900

Derecognition of Business - Add

Derecognition of Business - Additional Information (Details) - USD ($)		3 Months Ended	9 Months Ended
	Nov. 15, 2021	Sep. 30, 2022	Sep. 30, 2022
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Impairment of prepaid manufacturing services		$ 4,508,000	$ 4,508,000
Lonza
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Aggregate fair value of non-cash consideration	$ 39,200,000
Prepaid manufacturing services utilized		500,000	500,000
Asset Purchase Agreement | Lonza
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Consideration transactions	$ 65,000,000
Manufacturing Services Agreement | Lonza
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Clinical program period	4 years
Agreement termination advance notice period	12 months
Prepaid manufacturing services utilized		$ 500,000	500,000
Impairment of prepaid manufacturing services			4,500,000
License and Collaboration Agreement | Lonza
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Sublicense revenue			$ 0
Sublease Agreement | Lonza
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Lease commencement date	Nov. 15, 2021
Lease expiration date	Nov. 30, 2024
Annual fixed rent charges	$ 1,000,000
Percentage of annual increase in fixed rent charges	2.80%

Fair Value Measurements - Asset

Fair Value Measurements - Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - Recurring Basis - USD ($) $ in Thousands		Sep. 30, 2022	Dec. 31, 2021
Assets:
Assets			$ 67,603
Liabilities:
Liability		$ 5,428
Warrants
Liabilities:
Derivative liability		5,428
Money Market Funds
Assets:
Cash equivalents			67,603
Level 3
Liabilities:
Liability		5,428
Level 3 | Warrants
Liabilities:
Derivative liability		$ 5,428
Not Subject to Netting
Assets:
Assets	[1]		67,603
Not Subject to Netting | Money Market Funds
Assets:
Cash equivalents	[1]		$ 67,603
[1] Certain cash equivalents that are valued using the net asset value per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy.

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Fair Market Valuation of Warrants (Details) - Level 3	Sep. 30, 2022
Risk-free Rate
Fair market valuation of warrants line items
Valuation input	0.0406	[1]
Expected Term
Fair market valuation of warrants line items
Warrants term	4 years 11 months 15 days
Stock Price
Fair market valuation of warrants line items
Valuation input	0.78	[2]
Strike Price
Fair market valuation of warrants line items
Valuation input	1.88	[3]
Common Stock Volatility
Fair market valuation of warrants line items
Valuation input	0.7993	[4]
[1] Based on the U.S. Treasury yield curve, with terms commensurate with the expected term of the warrants. The closing price of the Company's common stock on the last trading day of the quarter ended September 30, 2022. As per the agreement for the warrant. Expected volatility based on historical volatility of the Company's peer companies that are commensurate with the expected term of the warrants.

Fair Value Measurements - Sch_2

Fair Value Measurements - Schedule of Change in Fair Value of Level 3 Warrants (Details) - Level 3 $ in Thousands	9 Months Ended
	Sep. 30, 2022 USD ($)
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Issuance fair value at September 15, 2022	$ 8,150
Change in fair value, recorded as a gain on derivative liability - warrants	(2,722)
Balance at September 30, 2022	$ 5,428

Accrued Expenses - Schedule of

Accrued Expenses - Schedule of Accrued Expenses (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Payables and Accruals [Abstract]
Employee compensation	$ 4,266	$ 5,142
External research and development costs	2,045	2,420
Professional services and consulting	1,201	1,523
Facilities costs	263	190
Other expenditures	351	428
Accrued expenses	$ 8,126	$ 9,703

Leases - Additional Information

Leases - Additional Information (Details)						3 Months Ended		9 Months Ended
	Nov. 15, 2021 USD ($) Renewal	Jul. 01, 2021	Apr. 27, 2020 USD ($) ft²	Mar. 22, 2019 USD ($) ft²	Mar. 05, 2019 USD ($) ft²	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)	Sep. 30, 2022 USD ($) Office	Sep. 30, 2021 USD ($)	Dec. 31, 2021 USD ($)
Lessee Lease Description [Line Items]
Lease expiration year								2029
Number of location | Office								2
Sublease income						$ 430,000	$ 484,000	$ 2,102,000	$ 1,188,000
4 Hartwell Place
Lessee Lease Description [Line Items]
Area of lease | ft²					18,707
Lease, base rent per year					$ 900,000
Increase in annual rent percentage					2.60%
Lease expiration month and year					2029-12
Lease commencement month and year					2019-07
Lessee, operating lease, existence of option to extend [true false]					true
Lessee, operating lease, option to extend								The Company has the option to extend the lease twice, each for a five-year period, on the same terms and conditions as the current lease, subject to a change in base rent based on market rates.
Lessee, operating lease, option to extend term					5 years
Tenant improvement allowance					$ 1,300,000
Tenant improvement allowance, received							$ 1,300,000		$ 1,300,000
Increase in base rent	$ 100,000
Initial direct cost	0
Operating right-of-use assets obtained in exchange for operating lease liabilities	1,000,000
Sublease payments to be received annually	$ 1,000,000
Sublease income, increase in annual percentage	2.80%
Sublease commencement date	Nov. 15, 2021
Sublease income expiration date	Nov. 30, 2024
Lessee, operating sublease, existence of option to extend	true
Lessee, operating sublease, option to extend								Lonza has the option to extend the sublease term for five 12-month periods on the same terms and conditions as the current sublease, subject to an increase of 2.8% in the annual fixed rent charges.
Number of operating sublease renewal term | Renewal	5
Lessee, operating sublease, option to extend term	12 months
Percentage of annual increase in fixed rent charges	2.80%
4 Hartwell Place | Letter of Credit
Lessee Lease Description [Line Items]
Security deposit						400,000		$ 400,000		$ 400,000
35 Cambridge Park Drive
Lessee Lease Description [Line Items]
Area of lease | ft²				68,258
Lease, base rent per year				$ 4,900,000
Increase in annual rent percentage				3%
Lease commencement date				Mar. 26, 2019
Lease expiration month and year				2029-11
Lessee, operating lease, existence of option to extend [true false]				true
Lessee, operating lease, option to extend								The Company has the option to extend the lease for a 10-year period on the same terms and conditions as the current lease, subject to a change in base rent based on market rates
Lessee, operating lease, option to extend term				10 years
Tenant improvement allowance				$ 12,300,000
Tenant improvement allowance, received						12,300,000		$ 12,300,000
Construction oversight fee				2%
Area of space for sublease | ft²			23,280
Sublease payments to be received annually			$ 1,300,000
Sublease income, increase in annual percentage		3%	3%
Sublease commencement date			May 18, 2020
Sublease expiration month and year		2023-05	2022-05
Lessee, operating sublease, existence of option to extend		true
Lessee, operating sublease, option to extend								Effective July 1, 2021, the sublessee exercised its option to extend the sublease for a one-year period through May 2023, on the same terms and conditions as the original sublease, subject to a change in base rent based on the greater of (i) an increase of 3.0% of the annual rent owed by the sublessee in year two, and (ii) market rent for the subleased premises
Lessee, operating sublease, option to extend term		1 year
Security deposit in connection with sublease			$ 300,000
35 Cambridge Park Drive | Other income
Lessee Lease Description [Line Items]
Write off of Leased Assets						400,000
35 Cambridge Park Drive | Letter of Credit
Lessee Lease Description [Line Items]
Security deposit						$ 3,700,000		$ 3,700,000		$ 3,700,000
Security deposit in connection with sublease			$ 300,000

Leases - Components of Operatin

Leases - Components of Operating Lease Costs (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Lease, Cost [Abstract]
Operating lease costs	$ 1,240	$ 1,208	$ 3,720	$ 3,626
Short-term lease costs	5	8	12	21
Variable lease costs	712	638	2,026	1,897
Sublease income	(430)	(484)	(2,102)	(1,188)
Lease, cost	$ 1,527	$ 1,370	$ 3,656	$ 4,356

Leases - Summary of Additional

Leases - Summary of Additional Lease Information (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Leases [Abstract]
Cash paid for amounts included in the measurement of operating lease liabilities	$ 4,700	$ 4,500
Weighted-average remaining lease term - operating leases (years)	7 years 2 months 12 days	8 years 2 months 12 days
Weighted-average discount rate - operating leases	10.10%	10.30%

Leases - Schedule of Undiscount

Leases - Schedule of Undiscounted Cash Flows Used in Calculating the Operating Lease Liabilities and Amounts to be Received under the Sublease (Details) $ in Thousands	Sep. 30, 2022 USD ($)
Leases [Abstract]
Operating Lease Payments, 2022 (remainder of the year)	$ 1,573
Operating Lease Payments, 2023	6,436
Operating Lease Payments, 2024	6,625
Operating Lease Payments, 2025	6,820
Operating Lease Payments, 2026	7,020
Operating Lease Payments, Thereafter	21,779
Operating Lease Payments, Total undiscounted cash flows	50,253
Operating Lease Payments, Less: Amounts representing interest	(14,669)
Operating Lease Payments, Present value of lease liabilities	35,584
Sublease Receipts, 2022 (remainder of the year)	250
Sublease Receipts, 2023	1,024
Sublease Receipts, 2024	965
Sublease Receipts, Total undiscounted cash flows	2,239
Net Operating Lease Payments, 2022 (remainder of the year)	1,323
Net Operating Lease Payments, 2023	5,412
Net Operating Lease Payments, 2024	5,660
Net Operating Lease Payments, 2025	6,820
Net Operating Lease Payments, 2026	7,020
Net Operating Lease Payments, Thereafter	21,779
Net Operating Lease Payments, Total undiscounted cash flows	$ 48,014

Commitments and contingencies -

Commitments and contingencies - Additional Information (Details) - Lonza - Manufacturing Services Agreement - USD ($)		9 Months Ended
	Nov. 15, 2021	Sep. 30, 2022
Commitments And Contingencies [Line Items]
Cancellation fees and other charges		$ 0
MinimumNonCancelablePurchaseObligation		0
Agreement termination advance notice period	12 months
Impairment of prepaid manufacturing services		4,500,000
Prepaid manufacturing services utilized		$ 500,000

Indebtedness - Additional Infor

Indebtedness - Additional Information (Details)				3 Months Ended		9 Months Ended
	Sep. 17, 2021 USD ($)	Jul. 24, 2020 USD ($)	Sep. 30, 2019 USD ($) Tranche	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)	Dec. 31, 2021 USD ($)	Sep. 16, 2021 USD ($)
Debt Instrument [Line Items]
Interest expense				$ 758,000	$ 689,000	$ 2,007,000	$ 2,091,000
Loan Agreement | Term Loan | Hercules
Debt Instrument [Line Items]
Aggregate principal amount									$ 75,000,000
Number of tranches | Tranche			4
Advanced amount under term loan			$ 25,000,000
Debt instrument, interest only payment end date			Nov. 01, 2022
Debt instrument repayment end date			Oct. 01, 2024
Debt instrument, end of term payment charge on funded amount percentage			5.60%
Loan carrying value		$ 15,000,000	$ 9,500,000	25,700,000		25,700,000		$ 25,400,000
Loan Agreement | Term Loan | Hercules | Maximum
Debt Instrument [Line Items]
Aggregate principal amount			75,000,000
Loan Agreement | Term Loan | Hercules | Second Tranche
Debt Instrument [Line Items]
Aggregate principal amount			10,000,000
Loan Agreement | Term Loan | Hercules | First Tranche
Debt Instrument [Line Items]
Advanced amount under term loan		$ 15,000,000	10,000,000
Amount payable upon any prepayment or repayment			1,400,000
Loan Agreement | Term Loan | Hercules | Third Tranche
Debt Instrument [Line Items]
Aggregate principal amount			10,000,000
Loan Agreement | Term Loan | Hercules | Fourth Tranche
Debt Instrument [Line Items]
Aggregate principal amount			$ 30,000,000
Amended Loan Agreement | Term Loan | Hercules
Debt Instrument [Line Items]
Debt instrument, covenants, obligated to maintain account cover amount percentage			110%
Interest expense				$ 800,000	$ 700,000	$ 2,000,000	$ 2,100,000
Amended Loan Agreement | Term Loan | Hercules | Second Tranche
Debt Instrument [Line Items]
Interest rate			1.50%
Amended Loan Agreement | Term Loan | Hercules | First Tranche
Debt Instrument [Line Items]
Interest rate			2%
Amended Loan Agreement | Term Loan | Hercules | Third Tranche
Debt Instrument [Line Items]
Interest rate			1%
Amended Loan Agreement | Amended Term Loan | Hercules
Debt Instrument [Line Items]
Aggregate principal amount	$ 85,000,000
Debt instrument, interest rate terms						Advances under the Amended Term Loan Facility bear interest at a rate equal to the greater of (i) 8.25% plus the Prime Rate (as reported in The Wall Street Journal) less 3.25%, and (ii) 8.25%.
Interest rate	8.25%
Debt instrument, interest only payment end date	Oct. 01, 2023
Debt instrument, interest only payment extendable end date	Oct. 01, 2024
Debt instrument repayment end date	Oct. 01, 2025
Debt instrument, end of term payment charge on funded amount percentage	5.50%
Amended Loan Agreement | Amended Term Loan | Hercules | Prime Rate
Debt Instrument [Line Items]
Variable interest rate	8.25%
Reduced from variable interest rate	3.25%
Amended Loan Agreement | Amended Term Loan | Hercules | Third Tranche
Debt Instrument [Line Items]
Aggregate principal amount	$ 10,000,000
Amended Loan Agreement | Amended Term Loan | Hercules | Fourth Tranche
Debt Instrument [Line Items]
Aggregate principal amount	30,000,000
Amended Loan Agreement | Amended Term Loan | Hercules | Fifth Tranche
Debt Instrument [Line Items]
Debt instrument, available in minimum draws	5,000,000
Amended Loan Agreement | Amended Term Loan | Hercules | Fifth Tranche | Maximum
Debt Instrument [Line Items]
Aggregate principal amount	$ 20,000,000

Indebtedness - Schedule of Futu

Indebtedness - Schedule of Future Principal Payments (Details) - Amended Loan Agreement $ in Thousands	Sep. 30, 2022 USD ($)
Debt Instrument [Line Items]
2023	$ 2,694
2024	11,559
2025	10,747
Long-term debt	$ 25,000

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Jan. 01, 2022	Oct. 31, 2020
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares of common stock reserved for future issuance						834,720
Annual increased percentage on outstanding common stock reserved						0.50%
Number of shares available for future issuance						208,680
Stock option, expiration period			10 years
Treasury stock, shares	0		0
Aggregate intrinsic value of stock options exercised	$ 0	$ 800	$ 0	$ 5,100
Stock-based compensation expense	2,287	$ 3,092	7,304	$ 8,055
Total unrecognized compensation expense related to stock compensation awards	$ 16,400		$ 16,400
Weighted-average period of unrecognized compensation expense related to stock compensation awards			2 years 3 months 18 days
2020 Stock Option and Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares of common stock reserved for future issuance						1,043,402
Additional shares of common stock reserved for future issuance					1,119,192
Number of shares available for future issuance	501,018		501,018
2020 Stock Option and Incentive Plan | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Annual increased percentage on outstanding common stock reserved						5%
2020 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares of common stock reserved for future issuance	0		0

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands		9 Months Ended	12 Months Ended
		Sep. 30, 2022	Dec. 31, 2021
Number of Shares
Outstanding		4,763,489
Granted		1,253,675
Forfeited/Cancelled		(796,424)
Outstanding		5,220,740	4,763,489
Exercisable		3,166,270
Vested and expected to vest		5,220,740
Weighted Average Exercise Price Per Share
Outstanding		$ 12.56
Granted		5.74
Forfeited/Cancelled		13.44
Outstanding		10.79	$ 12.56
Exercisable		10.08
Vested and expected to vest		$ 10.79
Weighted Average Remaining Contractual Term
Outstanding		5 years 11 months 23 days	6 years 5 months 8 days
Exercisable		4 years 6 months 10 days
Vested and expected to vest		5 years 11 months 23 days
Outstanding	[1]		$ 10,370
[1] Aggregate intrinsic value is calculated as the difference between the exercise price of the underlying options and the fair value of common stock for those stock options that had exercise prices lower than the fair value of the Company’s common stock as of September 30, 2022 and December 31, 2021 .

Stock-Based Compensation - Su_2

Stock-Based Compensation - Summary of Restricted Stock Unit Activity (Details) - Restricted Stock Units	9 Months Ended
	Sep. 30, 2022 $ / shares shares
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Granted | shares	1,896,683
Vested | shares	(130,164)
Forfeited/Cancelled | shares	(162,408)
Outstanding as of September 30, 2022 | shares	1,604,111
Vested and expected to vest as of September 30, 2022 | shares	1,604,111
Weighted Average Grant Date Fair Value
Granted | $ / shares	$ 3.21
Vested | $ / shares	5.18
Forfeited/Cancelled | $ / shares	5.86
Outstanding as of June 30, 2022 | $ / shares	0.74
Vested and expected to vest as of June 30, 2022 | $ / shares	$ 0.74

Stock-Based Compensation - Sche

Stock-Based Compensation - Schedule of Components and Classification of Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	$ 2,287	$ 3,092	$ 7,304	$ 8,055
Research and Development
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	1,121	1,646	3,262	3,925
General and Administrative
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	1,166	1,446	4,042	4,130
Employee
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	2,143	3,049	6,599	7,908
Non-employee
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	$ 144	$ 43	$ 705	$ 147

Collaboration Agreements - Summ

Collaboration Agreements - Summary of Total Consolidated Revenue from Strategic Collaborators (Details) - Collaboration - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Collaboration Agreements [Line Items]
Total collaboration revenue	$ 28	$ 1,157	$ 25,877	$ 15,238
Jazz
Collaboration Agreements [Line Items]
Total collaboration revenue	$ 28	118	26,044	11,225
Sarepta
Collaboration Agreements [Line Items]
Total collaboration revenue		$ 1,039	$ (167)	$ 4,013

Collaboration Agreements - Sche

Collaboration Agreements - Schedule of Changes in Contract Assets and Liabilities (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2022 USD ($)
Contract assets:
Accounts receivable, BALANCE BEGINNING OF PERIOD	$ 628	[1]
Accounts receivable, DEDUCTIONS	(628)	[1]
Contract liabilities:
Deferred revenue, BALANCE BEGINNING OF PERIOD	43,649
Deferred revenue, DEDUCTIONS	(26,044)
Deferred revenue, BALANCE END OF PERIOD	$ 17,605
[1] Included in prepaid expenses and other current assets as shown within the condensed consolidated balance sheets.

Collaboration Agreements - Sc_2

Collaboration Agreements - Schedule of Revenue Recognized (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Collaboration Agreements [Abstract]
Amounts included in deferred revenue at the beginning of the period	$ 28	$ 1,157	$ 26,044	$ 15,238

Collaboration Agreements - Su_2

Collaboration Agreements - Summary of Research and Development Costs Incurred and Revenue Recognized (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Collaboration Agreements [Line Items]
Revenue recognized	$ 28	$ 1,157	$ 26,044	$ 15,238
Sarepta Research Agreement
Collaboration Agreements [Line Items]
Revenue recognized		1,039	(167)	4,013
Costs incurred		1,039		4,013
Collaboration and License Agreement | Jazz Pharmaceuticals Ireland Limited
Collaboration Agreements [Line Items]
Revenue recognized	28	118	26,044	11,225
Costs incurred	$ 226	$ 606	$ 1,178	$ 1,947

Collaboration Agreements - Addi

Collaboration Agreements - Additional Information (Details)					1 Months Ended	3 Months Ended	9 Months Ended
	Dec. 03, 2021 USD ($)	Oct. 01, 2021	Jun. 30, 2021 USD ($)	Jan. 02, 2019 Target	Apr. 30, 2021 Target	Jun. 30, 2022 USD ($)	Sep. 30, 2022 USD ($) Target	Sep. 30, 2021 USD ($)	Mar. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Collaboration Agreements [Line Items]
Deferred revenue							$ 1,363,000			$ 12,963,000
Deferred revenue							$ 17,605,000
Collaboration and License Agreement | Jazz Pharmaceuticals Ireland Limited
Collaboration Agreements [Line Items]
Number of targets | Target				4
Number of oncogene targets discontinue work | Target					1		2
Number of oncogene targets | Target				5			5
Remaining deferred revenue recognized								$ 10,900,000
Total collaboration revenue			$ 2,800,000			$ 13,300,000
Deferred revenue							$ 26,000,000		$ 12,600,000
Changes in estimate of variable consideration							0
Deferred revenue							17,600,000			$ 43,600,000
Sarepta Research Agreement
Collaboration Agreements [Line Items]
Remaining deferred revenue recognized							$ 600,000
Total collaboration revenue	$ 13,900,000
Effective contract termination date		Dec. 03, 2021

Other Significant Agreements -

Other Significant Agreements - Additional Information (Details)		9 Months Ended	12 Months Ended	63 Months Ended
	Nov. 06, 2018 USD ($) shares	Sep. 30, 2022 USD ($) Milestone	Dec. 31, 2020 USD ($)	Feb. 01, 2021 USD ($)	Sep. 30, 2021 USD ($)	Nov. 30, 2015 USD ($)
MD Anderson Cancer Center | Patent and Technology License Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Remaining funding amount for patent-related costs under license agreement		$ 0
Number of days of prior written notice to terminate agreement		180 days
Number of milestones achieved | Milestone		0
Payments with respect to license agreement		$ 0			$ 0
MD Anderson Cancer Center | Patent and Technology License Agreement | Minimum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Patent costs				$ 1,500,000
MD Anderson Cancer Center | Patent and Technology License Agreement | Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Contingent future payments upon achievement of certain development and regulatory approval milestones						$ 11,900,000
Contingent payments in cash or through issuance of equity						4,400,000
MD Anderson Cancer Center | Patent and Technology License Agreement | Maximum | Diagnostic Products
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Contingent future payments upon achievement of certain development and regulatory approval milestones						2,400,000
MD Anderson Cancer Center | Patent and Technology License Agreement | Maximum | Therapeutic Products
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Contingent future payments upon achievement of certain development and regulatory approval milestones						$ 9,500,000
Kayla Therapeutics S.A.S | Kayla License Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Number of days of prior written notice to terminate agreement		30 days
Payments with respect to license agreement		$ 0
Royalty term determination period after first commercial sale of such product in such country		10 years
Number of days of notice to terminate agreement upon material breach		60 days
Kayla Therapeutics S.A.S | Kayla License Agreement | Phase 1/2 Clinical Trial
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Number of milestones achieved | Milestone		0
Non-refundable milestone payment in cash	$ 15,000,000
Non-refundable milestone payment in common stock | shares	177,318
Milestone payment			$ 15,000,000
Kayla Therapeutics S.A.S | Kayla License Agreement | Maximum | Phase 1/2 Clinical Trial
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Obligated to make cash payments upon achievement of clinical and regulatory milestones	$ 100,000,000
Value of common stock shares payable upon achievement of clinical and regulatory milestones	$ 13,000,000

Grant Revenue - Additional Info

Grant Revenue - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2022	Jul. 01, 2022
CEPI
Disaggregation of Revenue [Line Items]
Seed funding investment			$ 2,500
Deferred revenue	$ 1,100	$ 1,100
Grant award received	1,600	1,600
Grant
Disaggregation of Revenue [Line Items]
Revenue	494	494
Grant | CEPI
Disaggregation of Revenue [Line Items]
Revenue	$ 500	$ 500

Restructuring (Additional Infor

Restructuring (Additional Information) (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended	9 Months Ended
	Aug. 31, 2022	Sep. 30, 2022	Sep. 30, 2022
Restructuring Cost and Reserve [Line Items]
Percentage of reduction of the Company's workforce	37%
Restructuring charges		$ 700	$ 651
Non-cash stock-based compensation expense		200	200
Research and Development
Restructuring Cost and Reserve [Line Items]
Restructuring charges		500	500
General and Administrative
Restructuring Cost and Reserve [Line Items]
Restructuring charges		200	200
One-time Termination Benefits and Contractual Termination Benefits [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges		$ 500	$ 500

Restructuring - Summary of Rest

Restructuring - Summary of Restructuring Liability Activity (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2022
Restructuring and Related Activities [Abstract]
Restructuring charges	$ 700	$ 651
Severance payments		(329)
Stock-based compensation expense		(151)
Balance at September 30, 2022	$ 171	$ 171

Net Loss Per Share - Basic and

Net Loss Per Share - Basic and Diluted Net Loss Per Share Attributable to Common Stockholders (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2022	Sep. 30, 2021
Numerator:
Net loss	$ (19,278)	$ (6,775)	$ (8,028)	$ (21,702)	$ (21,809)	$ (10,308)	$ (34,081)	$ (53,819)
Net loss attributable to common stockholders	$ (19,278)			$ (21,702)			$ (34,081)	$ (53,819)
Denominator:
Weighted average common shares outstanding, basic	25,159,757			22,325,334			23,373,684	21,599,405
Weighted average common shares outstanding, diluted	25,159,757			22,325,334			23,373,684	21,599,405
Net loss per share attributable to common stockholders, basic	$ (0.77)			$ (0.97)			$ (1.46)	$ (2.49)
Net loss per share attributable to common stockholders, diluted	$ (0.77)			$ (0.97)			$ (1.46)	$ (2.49)

Net Loss Per Share - Anti-dilut

Net Loss Per Share - Anti-dilutive Securities Excluded from Calculation of Diluted Net Loss Per Share Attributable to Common Stockholders (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Outstanding awards	20,852,516	4,953,272	20,852,516	4,953,272
Restricted Stock Units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Outstanding awards	1,604,111		1,604,111
Warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Outstanding awards	14,027,665		14,027,665
Outstanding Stock Options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Outstanding awards	5,220,740	4,953,272	5,220,740	4,953,272