Curis (CRIS) 10-Q 4 Aug 22 2022 Q2 Quarterly report Financial data

Cover

Cover - shares	6 Months Ended
	Jun. 30, 2022	Jul. 28, 2022
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2022
Document Transition Report	false
Entity File Number	000-30347
Entity Registrant Name	CURIS, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	04-3505116
Entity Address, Address Line One	128 Spring Street
Entity Address, Address Line Two	Building C - Suite 500
Entity Address, City or Town	Lexington
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02421
City Area Code	617
Local Phone Number	503-6500
Title of 12(b) Security	Common Stock, Par Value $0.01 per share
Trading Symbol	CRIS
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		91,814,665
Amendment Flag	false
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q2
Entity Central Index Key	0001108205
Current Fiscal Year End Date	--12-31

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 34,008	$ 40,014
Short-term investments	73,192	75,870
Accounts receivable	2,395	3,224
Prepaid expenses and other current assets	3,801	3,267
Total current assets	113,396	122,375
Long-term investments	0	23,964
Property and equipment, net	789	505
Restricted cash, long-term	635	726
Operating lease right-of-use asset	5,032	5,749
Goodwill	8,982	8,982
Total assets	128,834	162,301
Current liabilities:
Accounts payable	5,511	6,417
Accrued liabilities	5,575	6,339
Current portion of operating lease liability	1,065	682
Total current liabilities	12,151	13,438
Long-term operating lease liability	3,390	4,358
Liability related to the sale of future royalties, net	51,248	53,798
Total liabilities	66,789	71,594
Stockholders’ equity:
Common stock, $0.01 par value—227,812,500 shares authorized; 91,814,665 shares issued and outstanding at June 30, 2022; 227,812,500 shares authorized; 91,645,369 shares issued and outstanding at December 31, 2021	918	916
Additional paid-in capital	1,186,056	1,182,225
Accumulated deficit	(1,124,374)	(1,092,325)
Accumulated other comprehensive loss	(555)	(109)
Total stockholders’ equity	62,045	90,707
Total liabilities and stockholders’ equity	$ 128,834	$ 162,301

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Jun. 30, 2022	Dec. 31, 2021
Statement of Financial Position [Abstract]
Common stock par value (in dollars per share)	$ 0.01	$ 0.01
Common stock authorized (in shares)	227,812,500	227,812,500
Common stock issued (in shares)	91,814,665	91,645,369
Common stock outstanding (in shares)	91,814,665	91,645,369

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Revenues, net:
Total revenues, net	$ 2,393	$ 2,286	$ 4,450	$ 4,475
Costs and expenses:
Cost of royalty revenues	42	116	124	225
Research and development	12,323	8,753	23,758	15,510
General and administrative	5,089	4,067	10,762	8,190
Total costs and expenses	17,454	12,936	34,644	23,925
Loss from operations	(15,061)	(10,650)	(30,194)	(19,450)
Other expense:
Interest income	162	58	242	104
Imputed interest expense related to the sale of future royalties	(1,041)	(1,136)	(2,097)	(2,309)
Other income (expense), net	0	890	0	890
Total other expense	(879)	(188)	(1,855)	(1,315)
Net loss	$ (15,940)	$ (10,838)	$ (32,049)	$ (20,765)
Net loss per common share (basic ) (in dollars per share)	$ (0.17)	$ (0.12)	$ (0.35)	$ (0.23)
Net loss per common share (diluted) (in dollars per share)	$ (0.17)	$ (0.12)	$ (0.35)	$ (0.23)
Weighted average common shares (basic) (in shares)	91,650,950	91,547,390	91,648,175	91,527,563
Weighted average common shares (diluted) (in shares)	91,650,950	91,547,390	91,648,175	91,527,563
Net loss	$ (15,940)	$ (10,838)	$ (32,049)	$ (20,765)
Other comprehensive income:
Unrealized loss on marketable securities	(104)	6	(446)	0
Comprehensive loss	(16,044)	(10,832)	(32,495)	(20,765)
Royalties
Revenues, net:
Total revenues, net	2,474	2,348	4,534	4,535
Other revenue
Revenues, net:
Total revenues, net	0	1	0	1
Contra revenue, net
Revenues, net:
Total revenues, net	$ (81)	$ (63)	$ (84)	$ (61)

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive (Loss) Income
Beginning balance (in shares) at Dec. 31, 2020		91,502,461
Beginning balance at Dec. 31, 2020	$ 130,670	$ 915	$ 1,176,647	$ (1,046,889)	$ (3)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Recognition of stock-based compensation	1,099		1,099
Exercise of stock options (in shares)		31,811
Exercise of stock options	79	$ 1	78
Unrealized gain (loss) on marketable securities	(6)				(6)
Net loss	(9,927)			(9,927)
Ending balance (in shares) at Mar. 31, 2021		91,534,272
Ending balance at Mar. 31, 2021	121,915	$ 916	1,177,824	(1,056,816)	(9)
Beginning balance (in shares) at Dec. 31, 2020		91,502,461
Beginning balance at Dec. 31, 2020	130,670	$ 915	1,176,647	(1,046,889)	(3)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(20,765)
Ending balance (in shares) at Jun. 30, 2021		91,596,369
Ending balance at Jun. 30, 2021	112,474	$ 916	1,179,215	(1,067,654)	(3)
Beginning balance (in shares) at Mar. 31, 2021		91,534,272
Beginning balance at Mar. 31, 2021	121,915	$ 916	1,177,824	(1,056,816)	(9)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Recognition of stock-based compensation	1,275		1,275
Issuance of stock under Employee Stock Purchase Plan (in shares)		20,791
Issuance of stock under Employee Stock Purchase Plan	68		68
Exercise of stock options (in shares)		41,306
Exercise of stock options	48		48
Unrealized gain (loss) on marketable securities	6				6
Net loss	(10,838)			(10,838)
Ending balance (in shares) at Jun. 30, 2021		91,596,369
Ending balance at Jun. 30, 2021	$ 112,474	$ 916	1,179,215	(1,067,654)	(3)
Beginning balance (in shares) at Dec. 31, 2021	91,645,369	91,645,369
Beginning balance at Dec. 31, 2021	$ 90,707	$ 916	1,182,225	(1,092,325)	(109)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Recognition of stock-based compensation	1,718		1,718
Unrealized gain (loss) on marketable securities	(342)				(342)
Net loss	(16,109)			(16,109)
Ending balance (in shares) at Mar. 31, 2022		91,645,369
Ending balance at Mar. 31, 2022	$ 75,974	$ 916	1,183,943	(1,108,434)	(451)
Beginning balance (in shares) at Dec. 31, 2021	91,645,369	91,645,369
Beginning balance at Dec. 31, 2021	$ 90,707	$ 916	1,182,225	(1,092,325)	(109)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options (in shares)	0
Net loss	$ (32,049)
Ending balance (in shares) at Jun. 30, 2022	91,814,665	91,814,665
Ending balance at Jun. 30, 2022	$ 62,045	$ 918	1,186,056	(1,124,374)	(555)
Beginning balance (in shares) at Mar. 31, 2022		91,645,369
Beginning balance at Mar. 31, 2022	75,974	$ 916	1,183,943	(1,108,434)	(451)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Recognition of stock-based compensation	1,966		1,966
Issuance of stock under Employee Stock Purchase Plan (in shares)		169,296
Issuance of stock under Employee Stock Purchase Plan	149	$ 2	147
Unrealized gain (loss) on marketable securities	(104)				(104)
Net loss	$ (15,940)			(15,940)
Ending balance (in shares) at Jun. 30, 2022	91,814,665	91,814,665
Ending balance at Jun. 30, 2022	$ 62,045	$ 918	$ 1,186,056	$ (1,124,374)	$ (555)

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Cash flows from operating activities:
Net loss	$ (32,049)	$ (20,765)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	80	84
Non-cash lease expense	529	407
Stock-based compensation expense	3,684	2,374
Non-cash imputed interest expense related to the sale of future royalties	6	3
Net amortization of premiums and discounts on marketable securities	575	634
Gain on forgiveness of PPP Loan	0	(890)
Changes in operating assets and liabilities:
Accounts receivable	829	664
Prepaid expenses and other assets	(536)	(366)
Accounts payable and accrued and other liabilities	(1,671)	(557)
Operating lease liability	(394)	(1,426)
Total adjustments	3,102	927
Net cash used in operating activities	(28,947)	(19,838)
Cash flows from investing activities:
Purchase of investments	(35,774)	(54,947)
Sales and maturities of investments	61,395	22,105
Purchase of property and equipment	(364)	0
Net cash provided by (used in) investing activities	25,257	(32,842)
Cash flows from financing activities:
Proceeds from issuance of common stock under the Company's share-based compensation plan	149	195
Payment of liability of future royalties, net of imputed interest	(2,556)	(2,099)
Net cash provided by (used in) financing activities	(2,407)	(1,904)
Net decrease in cash and cash equivalents and restricted cash	(6,097)	(54,584)
Cash and cash equivalents and restricted cash, beginning of period	40,740	130,426
Cash and cash equivalents and restricted cash, end of period	34,643	75,842
Supplemental cash flow data:
Cash paid for interest	2,091	2,305
Decrease in right-of-use assets and operating lease liabilities resulting from lease modification	$ (191)	$ 0

Nature of Business

Nature of Business	6 Months Ended
	Jun. 30, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of Business	Nature of Business Curis, Inc. is a biotechnology company focused on the development of first-in-class and innovative therapeutics for the treatment of cancer. Throughout these Condensed Consolidated Financial Statements, Curis, Inc. and its wholly owned subsidiaries are collectively referred to as “the Company” or “Curis.” The Company conducts its research and development programs both internally and through strategic collaborations. The Company’s clinical stage drug candidates include emavusertib, previously CA-4948, an orally available small molecule inhibitor of Interleukin-1 receptor associated kinase 4 (“IRAK4”); CI-8993, a monoclonal antibody designed to antagonize the V-domain Ig suppressor of T cell activation (“VISTA”) signaling pathway; fimepinostat, a small molecule that potently inhibits the activity of histone deacetylase and phosphotidyl-inositol 3 kinase enzymes; and CA-170, a small molecule antagonist of VISTA and PDL1. The Company's pre-clinical development candidates include CA-327, an orally available small molecule antagonist of PDL1 and TIM3. The Company is party to a collaboration with Genentech Inc. (“Genentech”), a member of the Roche Group, under which Genentech and F. Hoffmann-La Roche Ltd (“Roche”) are commercializing Erivedge® (vismodegib), a first-in-class orally administered small molecule Hedgehog signaling pathway antagonist. Erivedge is approved for the treatment of advanced basal cell carcinoma (“BCC”). In January 2015, the Company entered into an exclusive collaboration agreement with Aurigene Discovery Technologies Limited (“Aurigene”) for the discovery, development and commercialization of small molecule compounds in the areas of immuno-oncology and precision oncology, which was amended in September 2016 and February 2020. In addition, the Company is a party to an option and license agreement with ImmuNext. Pursuant to the terms of the option and license agreement, the Company has an option, exercisable for a specified period as set forth in the option and license agreement, to obtain an exclusive license to develop and commercialize certain VISTA antagonizing compounds, including ImmuNext's lead compound, CI-8993, and products containing these compounds in the field of oncology. The COVID-19 pandemic has had and may continue to have an adverse effect on the Company’s business, financial condition, results of operations, and prospects. With respect to ongoing clinical trials, the anticipated timing of enrollment and the overall timelines of the trials have experienced delays and could be further delayed to the extent the Company experiences further delays in enrollment due to the COVID-19 pandemic. The Company’s ability to collect patient data in a timely fashion may also be impacted. The Company also experienced delays in closing down its clinical trial sites related to its fimepinostat and CA-170 trials due to restrictions on non-essential workers imposed at those sites in response to COVID-19, which delayed the winding down of these trials. In addition, the Company and its collaborators, third-party contract manufacturers, contract research organizations and clinical sites could experience delays or disruptions in supply and release of product candidates and/or procuring items that are essential for its research and development activities, including, for example, raw materials used in the manufacturing of its product candidates, basic medical and laboratory supplies used in its clinical trials or preclinical studies, or animals that are used for preclinical testing, in each case, for which there may be shortages or supply chain disruptions as a result of the continuing pandemic. The Company cannot be certain what the overall impact of the COVID-19 pandemic will be on its business. The Company is subject to risks common to companies in the biotechnology industry as well as risks that are specific to the Company’s business, including, but not limited to: the Company’s ability to obtain adequate financing to fund its operations; the Company’s ability to advance and expand its research and development programs; the impacts of the COVID-19 pandemic and responsive actions related thereto; the Company’s reliance on Roche and Genentech to successfully commercialize Erivedge in the approved indication of advanced BCC and to progress its clinical development in indications other than BCC; the ability of the Company and its wholly owned subsidiary, Curis Royalty, LLC (“Curis Royalty”) to satisfy the terms of the royalty interest purchase agreement (the “Oberland Purchase Agreement”) with TPC Investments I LP and TPC Investments II LP ("the Purchasers"), each of which is a Delaware limited partnership managed by Oberland Capital Management, LLC, and Lind SA LLC ("the Agent"), a Delaware limited liability company managed by Oberland Capital Management, LLC, as collateral agent for the Purchasers; the Company’s ability to obtain and maintain necessary intellectual property protection; development by the Company’s competitors of new or better technological innovations; the Company’s ability to comply with regulatory requirements; the Company's ability to obtain and maintain applicable regulatory approvals and commercialize any approved product candidates; and the Company’s ability to execute on its overall business strategies. The Company’s future operating results will largely depend on the progress of drug candidates currently in its development pipeline and the magnitude of payments that it may receive and make under its current and potential future collaborations. The results of the Company’s operations have varied and will likely continue to vary significantly from year to year and quarter to quarter and depend on a number of factors, including, but not limited to the timing, outcome and cost of the Company’s preclinical studies and clinical trials for its drug candidates. The Company will require substantial funds to maintain research and development programs and support operations. The Company has incurred net losses and negative cash flows from operations since its inception. As of June 30, 2022, the Company had an accumulated deficit of $1.1 billion, and for the six months ended June 30, 2022, the Company incurred a net loss of $32.0 million and used $28.9 million of cash in operations. The Company expects to continue to generate operating losses in the foreseeable future. The Company anticipates that its $107.2 million of existing cash, cash equivalents and investments at June 30, 2022 will be sufficient to fund operations for at least 12 months from the date of filing this Quarterly Report on Form 10-Q. The Company’s ability to raise additional funds will depend, among other factors, on financial, economic and market conditions, many of which are outside of its control and it may be unable to raise financing when needed, or on terms favorable to the Company. If necessary funds are not available, the Company will have to delay, reduce the scope of, or eliminate some of its development programs, potentially delaying the time to market for or preventing the marketing of any of its product candidates.

Summary of Significant Accounti

Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies (a) Basis of Presentation and Principles of Consolidation The accompanying Condensed Consolidated Financial Statements have been prepared in accordance with the instructions to Form 10-Q and Rule 10-01 of Regulation S-X. These statements, however, are condensed and do not include all disclosures required by accounting principles generally accepted in the U.S. (“GAAP”), for complete financial statements and should be read in conjunction with the Company’s Annual Report on Form 10-K for the year ended December 31, 2021 as filed with the Securities and Exchange Commission (“SEC”), on February 24, 2022. In the opinion of the management of the Company, the unaudited financial statements contain all adjustments (all of which were considered normal and recurring) necessary for a fair statement of the Company’s financial position at June 30, 2022; the results of operations for the three and six-month periods ended June 30, 2022 and 2021; stockholders' equity for the three and six-month periods ended June 30, 2022 and 2021; and the cash flows for the six-month periods ended June 30, 2022 and 2021. The Condensed Consolidated Balance Sheet at December 31, 2021 was derived from audited annual financial statements but does not contain all of the footnote disclosures from the annual financial statements. (b) Use of Estimates and Assumptions The preparation of the Company’s Condensed Consolidated Financial Statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts and disclosure of certain assets and liabilities at the balance sheet date. Such estimates include the performance obligations under the Company’s collaboration agreements; the estimated repayment term of the Company’s debt and related short- and long-term classification; the collectability of receivables; the carrying value of property and equipment and goodwill; and the assumptions used in the Company’s valuation of stock-based compensation and the value of certain investments and liabilities. Actual results may differ from such estimates. These interim results are not necessarily indicative of results to be expected for a full year or subsequent interim periods. The extent to which COVID-19 has had and may continue to have impacts on the Company’s business and financial results will depend on numerous evolving factors including, but not limited to: the magnitude and duration of the continuing COVID-19 pandemic, the extent to which it has impacted and may continue to impact worldwide macroeconomic conditions including interest rates, employment rates and health insurance coverage, the speed of the anticipated recovery, and governmental and business responses to the pandemic. The Company assessed certain accounting matters that generally require consideration of forecasted financial information in context with the information reasonably available to the Company and the unknown future impacts of COVID-19 as of June 30, 2022 and through the date of this report. The Company’s future assessment of the magnitude and duration of the COVID-19 pandemic, as well as other factors, could result in material impacts to the Company’s consolidated financial statements in future reporting periods. (c) Cash Equivalents, Restricted Cash, and Investments Cash equivalents consist of highly liquid investments purchased with original maturities of three months or less. All other liquid investments are classified as marketable securities. The Company classified $0.6 million and $0.7 million of its cash as restricted cash as June 30, 2022 and December 31, 2021, respectively. This amount represents the security deposit on the Company's current Massachusetts headquarters. The Company's combined cash and cash equivalents and restricted cash balances were $34.6 million and $75.8 million as of June 30, 2022 and June 30, 2021, respectively, as presented on the Company's Condensed Consolidated Statements of Cash Flows. The Company’s short-term investments are marketable debt securities with original maturities of greater than three months from the date of purchase, but less than twelve months from the balance sheet date, and long-term investments are marketable debt securities with original maturities of greater than twelve months from the balance sheet date. Marketable securities consist of commercial paper, corporate bonds and notes, and/or government obligations. All of the Company’s investments have been designated available-for-sale and are stated at fair value. Unrealized gains and temporary losses on investments are included in accumulated other comprehensive income (loss) as a separate component of stockholders’ equity (deficit). Realized gains and losses, dividends and interest income are included in other income (expense) in the period during which the securities are sold. Any premium or discount arising at purchase is amortized and/or accreted to interest income. Accrued interest receivable related to the Company's available-for-sale debt securities is presented within investments on the Company's consolidated balance sheets. Any write offs of accrued interest receivable are recorded by reversing interest income, recognizing credit loss expense, or a combination of both. To date, the Company has not written off any accrued interest receivables associated with its marketable securities. (d) Leases The Company determines if an arrangement is a lease at contract inception. Operating lease assets represent the Company's right to use an underlying asset for the lease term and operating lease liabilities represent its obligation to make lease payments arising from the lease. Operating lease assets and liabilities are recognized at the commencement date of the lease based upon the present value of lease payments over the lease term. When determining the lease term, the Company includes options to extend or terminate the lease when it is reasonably certain that the Company will exercise that option. As the Company's lease does not provide an implicit interest rate, the Company uses its incremental borrowing rate, which is based on rates that would be incurred to borrow on a collateralized basis over a term equal to the lease payments in a similar economic environment, in determining the present value of lease payments. Right-of-use assets and lease liabilities are recognized at the lease commencement date based on the present value of lease payments over the lease term. The lease payment used to determine the operating lease asset may include lease incentives, stated rent increases and was recognized as an operating lease right-of-use asset in the Condensed Consolidated Balance Sheets. The Company's lease agreements may include both lease and non-lease components, which are accounted for as a single lease component when the payments are fixed. Variable payments included in the lease agreement are expensed as incurred. The Company's operating lease is reflected in operating lease right-of-use asset and operating lease liability in the Condensed Consolidated Balance Sheets. Lease expense for lease payments is recognized on a straight-line basis over the lease term. (e) Revenue Recognition The Company’s business strategy includes entering into collaborative license and development agreements with biotechnology and pharmaceutical companies for the development and commercialization of the Company’s drug candidates. The terms of the agreements typically include non-refundable license fees, funding of research and development, payments based upon achievement of clinical development and regulatory objectives, and royalties on product sales. License Fees and Multiple Element Arrangements If a license to its intellectual property is determined to be distinct from the other performance obligations identified in the arrangement, the Company will recognize revenues from non-refundable, up-front fees allocated to the license at such time as the license is transferred to the licensee and the licensee is able to use, and benefit from, the license. For licenses that are bundled with other promises, the Company utilizes judgment to assess the nature of the combined performance obligation to determine whether the combined performance obligation is satisfied over time or at a point in time and, if over time, the appropriate method of measuring progress for purposes of recognizing revenue from non-refundable, up-front fees. The Company evaluates the measure of progress each reporting period and, if necessary, will adjust the measure of performance and related revenue recognition. If the Company is involved in a steering committee as part of a multiple element arrangement, the Company assesses whether its involvement constitutes a performance obligation or a right to participate. Steering committee services that are not determined to be distinct performance obligations are combined with other research services or performance obligations required under an arrangement, if any, in determining the level of effort required in an arrangement and the period over which the Company expects to complete its aggregate performance obligations. Appropriate methods of measuring progress include output methods and input methods. In determining the appropriate method for measuring progress, the Company considers the nature of service that it promises to transfer to the customer. When the Company decides on a method of measurement, the Company will apply that single method of measuring progress for each performance obligation satisfied over time and will apply that method consistently to similar performance obligations and in similar circumstances. If the Company cannot reasonably measure its progress toward complete satisfaction of a performance obligation because the Company lacks reliable information that would be required to apply an appropriate method of measuring progress, but it can reasonably estimate when the performance ceases or the remaining obligations become inconsequential and perfunctory, then revenue is not recognized until the Company can reasonably estimate when the performance obligation ceases or becomes inconsequential. Revenue is then recognized over the remaining estimated period of performance. Significant management judgment is required in determining the level of effort required under an arrangement and the period over which the Company is expected to complete its performance obligations under an arrangement. Contingent Research Milestone Payments Accounting Standards Codification ("ASC") 606 constrains the amount of variable consideration included in the transaction price in that either all, or a portion, of an amount of variable consideration should be included in the transaction price. The variable consideration amount should be included only to the extent that it is probable that a significant reversal in the amount of cumulative revenue recognized will not occur when the uncertainty associated with the variable consideration is subsequently resolved. The assessment of whether variable consideration should be constrained is largely a qualitative one that has two elements: the likelihood of a change in estimate, and the magnitude thereof. Variable consideration is not constrained if the potential reversal of cumulative revenue recognized is not significant, for example. If the consideration in a contract includes a variable amount, a company will estimate the amount of consideration in exchange for transfer of promised goods or services. The consideration also can vary if a company’s entitlement to the consideration is contingent on the occurrence or nonoccurrence of a future event. The Company considers contingent research milestone payments to fall under the scope of variable consideration, which should be estimated for revenue recognition purposes at the inception of the contract and reassessed ongoing at the end of each reporting period. The Company assesses whether contingent research milestones should be considered variable consideration that should be constrained and thus not part of the transaction price. This includes an assessment of the probability that all or some of the milestone revenues could be reversed when the uncertainty around whether or not the achievement of each milestone is resolved, and the amount of reversal could be significant. GAAP provides factors to consider when assessing whether variable consideration should be constrained. All of the factors should be considered, and no factor is determinative. The Company considers all relevant factors. Reimbursement of Costs Reimbursement of research and development costs by third-party collaborators is recognized as revenue over time provided the Company has determined that it transfers control (i.e. performs the services) of a service over time and, therefore, satisfies a performance obligation according to the provisions outlined in ASC 606-10-25-27, Revenue Recognition . Royalty Revenue The Company recognizes royalty revenues related to Genentech’s and Roche’s sales of Erivedge. For arrangements that include sales-based royalties, including milestone payments based on the level of sales, and where the license is deemed to be the predominant item to which the royalties relate, the Company recognizes revenue at the later of (i) when the related sales occur, or (ii) when the performance obligation to which some or all of the royalty has been allocated has been satisfied (or partially satisfied). The Company expects to continue recognizing royalty revenue from Genentech’s sales of Erivedge in the U.S. and in other markets where Genentech and Roche successfully obtain marketing approval, if any (see Note 9, Research and Development Collaborations ). However, a portion of potential Erivedge royalties will be paid to the Purchasers pursuant to the Oberland Purchase Agreement (see Note 8, Liability Related to the Sale of Future Royalties ). Contra Revenue, Net Contra revenue, net represents shared costs, primarily related to intellectual property, with the Company's collaboration partners. With respect to each of the foregoing areas of revenue recognition, the Company exercises significant judgment in determining whether an arrangement contains multiple elements, and, if so, how much revenue is allocable to each element. In addition, the Company exercises its judgment in determining when its significant obligations have been met under such agreements and the specific time periods over which the Company recognized revenue, such as non-refundable, up-front license fees. To the extent that actual facts and circumstances differ from the Company's initial judgments, its revenue recognition with respect to such transactions would change accordingly and any such change could affect the Company's reported financial results. Summary During each of the three and six months ended June 30, 2022, 100% of the Company's total gross revenues were derived from the Company’s collaboration with Genentech. During each of the three and six months ended June 30, 2021, 99% of the Company's total gross revenues were derived from the Company’s collaboration with Genentech. (f) Segment Reporting The Company operates in a single reportable segment, which is the research and development of innovative cancer therapies. (g) New Accounting Pronouncements The Company considers the applicability and impact of any recent Accounting Standards Update (“ASU”) issued by the Financial Accounting Standards Board (“FASB”). Based on the assessment, the ASUs were determined to be either not applicable or are expected to have minimal impact on the Company's condensed consolidated financial statements.

Fair Value of Financial Instrum

Fair Value of Financial Instruments	6 Months Ended
	Jun. 30, 2022
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	Fair Value of Financial Instruments The Company has adopted the provisions of the FASB Codification Topic 820, Fair Value Measurements and Disclosures (“Topic 820”) for its financial assets and liabilities that are re-measured and reported at fair value each reporting period and the non-financial assets and liabilities that are re-measured and reported at fair value on a non-recurring basis. Fair value is the price that would be received from selling an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. When determining fair value, the Company considers the principal or most advantageous market in which it would transact and consider assumptions that market participants would use when pricing the asset or liability. Topic 820 establishes a three-level valuation hierarchy for disclosure of fair value measurements. Financial assets and liabilities are categorized within the valuation hierarchy based upon the lowest level of input that is significant to the measurement of fair value. The three levels of the hierarchy are defined as follows: Level 1 Quoted prices in active markets for identical assets or liabilities. Level 2 Observable inputs other than Level 1 prices, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. Level 3 Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. In accordance with the fair value hierarchy, the following table shows the fair value as of June 30, 2022 and December 31, 2021 of those financial assets and liabilities that are measured at fair value on a recurring basis, according to the valuation techniques the Company used to determine their fair value. No financial assets or liabilities are measured at fair value on a nonrecurring basis at June 30, 2022 and December 31, 2021. (in thousands) Quoted Prices in Other Observable Unobservable Fair Value As of June 30, 2022: Cash equivalents: Money market funds $ 31,371 $ — $ — $ 31,371 Short-term investments: Corporate commercial paper, bonds and notes — 73,192 — 73,192 Total $ 31,371 $ 73,192 $ — $ 104,563 (in thousands) Quoted Prices in Other Observable Unobservable Fair Value As of December 31, 2021: Cash equivalents: Money market funds $ 33,944 $ — $ — $ 33,944 Short-term investments: Corporate commercial paper, bonds and notes — 75,870 — 75,870 Long-term investments: Corporate commercial paper, bonds and notes — 23,964 — 23,964 Total $ 33,944 $ 99,834 $ — $ 133,778

Investments

Investments	6 Months Ended
	Jun. 30, 2022
Investments, Debt and Equity Securities [Abstract]
Investments	Investments The amortized cost, including interest receivable, unrealized gains and losses and fair value of investments available-for-sale as of June 30, 2022 are as follows: (in thousands) Amortized Unrealized Unrealized Fair Value Corporate bonds and notes—short-term $ 73,747 $ — $ (555) $ 73,192 Total investments $ 73,747 $ — $ (555) $ 73,192 Short-term investments have maturities ranging from one The amortized cost, including interest receivable, unrealized gains and losses and fair value of investments available-for-sale as of December 31, 2021 are as follows: (in thousands) Amortized Unrealized Unrealized Fair Value Corporate bonds and notes—short-term $ 75,896 $ — $ (26) $ 75,870 Corporate bonds and notes—long-term 24,047 — (83) 23,964 Total investments $ 99,943 $ — $ (109) $ 99,834 Short-term investments have maturities ranging from one No credit losses on available-for-sale securities were recognized during the three and six months ended June 30, 2022 or June 30, 2021. In its evaluation to determine expected credit losses, management considered all available historical and current information, expectations of future economic conditions, the type of security, the credit rating of the security, and the size of the loss position, as well as other relevant information. The Company does not intend to sell, and is unlikely to be required to sell, any of these available-for-sale investments before their effective maturity or market price recovery.

Accrued Liabilities

Accrued Liabilities	6 Months Ended
	Jun. 30, 2022
Other Liabilities Disclosure [Abstract]
Accrued Liabilities	Accrued Liabilities Accrued liabilities consisted of the following: (in thousands) June 30, 2022 December 31, 2021 Compensation and related costs $ 2,708 $ 3,260 Chemistry, manufacturing and controls costs 1,515 2,232 Professional and legal fees 828 644 Other 524 203 Total $ 5,575 $ 6,339

Debt

Debt	6 Months Ended
	Jun. 30, 2022
Debt Disclosure [Abstract]
Debt	DebtIn April 2020, the Company entered into a promissory note evidencing an unsecured $0.9 million loan (the “PPP Loan”) under the Paycheck Protection Program (“PPP”), of the Coronavirus Aid, Relief, and Economic Security Act (“CARES Act”) as administered by the U.S. Small Business Administration (the "SBA"). The PPP Loan was made by Silicon Valley Bank and had a term of 24-months and an interest rate of 1%. Under the terms of the CARES Act and the Paycheck Protection Program Flexibility Act of 2020, PPP Loan recipients can apply for and be granted forgiveness for all or a portion of loans granted under the PPP. The Company applied for such forgiveness in 2020 and received notification in June 2021 that the SBA had forgiven the PPP Loan in full, including interest accrued on the PPP Loan. The Company recorded a gain of $0.9 million to Other income (expense), net for extinguishment of the debt during the three and six months ended June 30, 2021.

Lease

Lease	6 Months Ended
	Jun. 30, 2022
Leases [Abstract]
Lease	Lease The Company has a single lease for real estate, including laboratory and office space, and certain equipment. The lease at 128 Spring Street in Lexington, Massachusetts commenced on May 1, 2020 which is the date when the property became available for use to the Company. In accordance with the accounting requirements under ASC 842, the lease obligation was not recorded until its commencement. In January 2022, the Company amended its lease agreement at 128 Spring Street ("Lease Amendment"). The Lease Amendment added approximately 9,340 square feet to the existing space for $30 per square foot, or $0.3 million per year in base rent subject to annual rent increases. Rent for the additional space is paid on a “gross amount” basis and the Company is not obligated to reimburse the landlord for taxes or operating expenses on the additional space. Payments under the Lease Amendment commenced when the Company took possession of the space during the second quarter of 2022. In addition, the Lease Amendment provides the Company and the landlord each with an option to terminate the lease agreement early. The Company's early termination option becomes effective on the lease commencement date of a new lease for larger premises within the landlord’s commercial real estate portfolio (“New Lease”), and the Company may exercise its early termination option by providing the landlord with written notice of such election to terminate the lease agreement concurrently with the execution of the New Lease. The landlord has the option to terminate the lease agreement early by providing written notice to the Company eighteen months prior to December 31, 2025. We expect the lease to end as of December 31, 2025. The Lease Amendment constitutes a modification as it reduces the original lease term and increases the scope of the lease (additional space provided under the Lease Amendment), which requires evaluation of the remeasurement of the lease liability and corresponding right-of-use asset. The additional space did not result in a separate contract as the rent increase was determined not to be commensurate with the standalone price for the additional right of use. Accordingly, the Company reassessed the classification of the lease, and concluded it is an operating lease, and remeasured the lease liability on the basis of the reduced lease term as of the effective date of the modification. The discount rate associated with the Company’s right-of-use asset is 9.95%. The shortened lease term and resulting remeasurement for the modification resulted in a decrease to the lease liability and the right-of-use asset of $1.1 million during the three months ended March 31, 2022. The additional space provided under the Lease Amendment and resulting remeasurement for the modification resulted in an increase to the lease liability and the right-of-use asset of $0.9 million during the three months ended June 30, 2022 As of June 30, 2022, the Company had an operating lease liability of $4.5 million and related right-of-use asset of $5.0 million related to its operating lease. As of December 31, 2021, the Company had an operating lease liability of $5.0 million and related right-of-use asset of $5.7 million related to its operating lease.

Liability Related to the Sale o

Liability Related to the Sale of Future Royalties	6 Months Ended
	Jun. 30, 2022
Nonmonetary Transactions [Abstract]
Liability Related to the Sale of Future Royalties	Liability Related to the Sale of Future Royalties In March 2019, the Company and Curis Royalty entered into the royalty interest purchase agreement (“Oberland Purchase Agreement”) with entities managed by Oberland Capital Management, LLC (the “Purchasers”). The Company sold to the Purchasers a portion of its rights to receive royalties from Genentech on potential net sales of Erivedge. Concurrently with the closing of the Oberland Purchase Agreement, Curis Royalty used a portion of the proceeds to terminate and repay the then existing loan with HealthCare Royalty Partners, III, L.P. As upfront consideration for the purchase of the royalty rights, at closing the Purchasers paid to Curis Royalty $65.0 million less certain transaction expenses. Curis Royalty will also be entitled to receive up to $53.5 million in milestone payments based on sales of Erivedge if the Purchasers receive payments pursuant to the Oberland Purchase Agreement in excess of $117.0 million on or prior to December 31, 2026. The Oberland Purchase Agreement provides that after the occurrence of an event of default as defined under the security agreement by Curis Royalty, the Purchasers shall have the option, for a period of 180 days, to require Curis Royalty to repurchase a portion of certain royalty and royalty related payments, excluding a portion of non U.S. royalties retained by Curis Royalty (the “Purchased Receivables”), at a price (the “Put/Call Price”), equal to a percentage, beginning at a low triple digit percentage and increasing over time up to a low mid triple digit percentage of the sum of the upfront purchase price and any portion of the milestone payments paid in a lump sum by the Purchasers, if any, minus certain payments previously received by the Purchasers with respect to the Purchased Receivables. The Company concluded the put option is an embedded derivative that requires bifurcation from the deferred royalty obligation and the value of the option is de minimis. Additionally, Curis Royalty shall have the option at any time to repurchase the Purchased Receivables at the Put/Call Price as of the date of such repurchase. No events of default occurred had as of June 30, 2022. As a result of the obligation to pay future royalties to Oberland, the Company recorded the proceeds from this transaction as a liability on its Consolidated Balance Sheet that will be accounted for using the interest method over the estimated life of the Oberland Purchase Agreement. As a result, the Company imputes interest on the transaction and records imputed interest expense at the estimated interest rate. The Company's estimate of the interest rate under the agreement is based on the amount of royalty payments expected to be received by Oberland over the life of the arrangement. The projected amount of royalty payments expected to be paid to Oberland involves the use of significant estimates and assumptions with respect to the revenue growth rate in the Company's projections of sales of Erivedge. The Company periodically assesses the expected royalty payments to Curis Royalty from Genentech using a combination of historical results and forecasts from market data sources. To the extent such payments are greater or less than its initial estimates or the timing of such payments is materially different than its original estimates, the Company will adjust the amortization of the liability. The Company determined the fair value of the liability related to the sale of future royalties at the time of the Oberland Purchase Agreement to be $65.0 million, with a current effective annual imputed interest rate of 7.9%. The Company incurred $0.6 million of transaction costs in connection with the agreement. These transaction costs are amortized to imputed interest expense over the estimated term of the Oberland Purchase Agreement. The Company determined that the fair value assessment of the liability related to the sale of future royalties is a Level 3 assessment within the valuation hierarchy. The following table shows the activity with respect to the liability related to the sale of future royalties during the six months ended June 30, 2022. (in thousands) Carrying value of liability related to the sale of future royalties at January 1, 2022 $ 53,798 Amortization of capitalized issuance costs 31 Imputed interest expense recognized for the six months ending June 30, 2022 2,065 Less: payments to Oberland Capital, LLC (4,646) Carrying value of liability related to the sale of future royalties at June 30, 2022 $ 51,248

Research and Development Collab

Research and Development Collaborations	6 Months Ended
	Jun. 30, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Research and Development Collaborations	Research and Development Collaborations (a) Genentech In June 2003, the Company licensed its proprietary Hedgehog pathway antagonist technologies to Genentech for human therapeutic use. The primary focus of the collaborative research plan has been to develop molecules that inhibit the Hedgehog pathway for the treatment of various cancers. The collaboration is currently focused on the development of Erivedge, which is being commercialized by Genentech in the U.S. and by Genentech’s parent company, Roche, in several other countries for the treatment of advanced BCC. Pursuant to the agreement, the Company is eligible to receive up to an aggregate of $115.0 million in contingent cash milestone payments, exclusive of royalty payments, in connection with the development of Erivedge or another small molecule Hedgehog pathway inhibitor, assuming the successful achievement by Genentech and Roche of specified clinical development and regulatory objectives. Of this amount, the Company has received $59.0 million in cash milestone payments as of June 30, 2022. In addition to these payments and pursuant to the collaboration agreement, the Company is entitled to a royalty on net sales of Erivedge that ranges from 5% to 7.5%. The royalty rate applicable to Erivedge may be decreased by 2% on a country-by-country basis in certain specified circumstances. The Company recognized $2.5 million and $2.3 million in royalty revenue under the Genentech collaboration during the three months ended June 30, 2022 and 2021, respectively. The Company recognized $4.5 million in royalty revenue under the Genentech collaboration during both the six months ended June 30, 2022 and 2021. The Company also recorded cost of royalty revenues within the costs and expenses section of its Condensed Consolidated Statements of Operations and Comprehensive Loss of less than $0.1 million during the three months ended June 30, 2022 and $0.1 million during the three months ended June 30, 2021. The Company recorded $0.1 million of costs of royalty revenues during the six months ended June 30, 2022 and $0.2 million during the six months ended June 30, 2021. Cost of royalty revenues is comprised of amounts due to third-party university patent licensors in connection with Genentech and Roche's Erivedge net sales. The Company recorded receivables from Genentech under this collaboration for Erivedge royalties earned during the period. The receivable recorded in the Company's current assets section of its Condensed Consolidated Balance Sheets amounted to $2.4 million as of June 30, 2022 and $3.2 million as of December 31, 2021. As previously discussed in Note 8, Liability Related to the Sale of Future Royalties, a portion of royalty revenues received from Genentech on net sales of Erivedge will be paid to the Purchasers pursuant to the Oberland Purchase Agreement. (b) Aurigene In January 2015, the Company entered into an exclusive collaboration agreement with Aurigene for the discovery, development and commercialization of small molecule compounds in the areas of immuno-oncology and selected precision oncology targets, which was first amended in September 2016. Under the collaboration agreement, Aurigene granted the Company an option to obtain exclusive, royalty-bearing licenses to relevant Aurigene technology to develop, manufacture and commercialize products containing certain of such compounds anywhere in the world, except for India and Russia, which are territories retained by Aurigene. In February 2020, the collaboration agreement was further amended whereby Aurigene received rights to develop and commercialize CA-170 in Asia in addition to its existing rights in India and Russia, and the Company became entitled to receive royalty payments on potential future sales of CA-170 in Asia at percentage rates ranging from the high single digits up to 10% subject to specified reductions. As of June 30, 2022, the Company has exercised its option to license the following four programs under the collaboration: 1. IRAK4 Program - a precision oncology program of small molecule inhibitors of IRAK4. The development candidate is emavusertib (CA-4948), an orally available small molecule inhibitor of IRAK4. 2. PD1/VISTA Program - an immuno-oncology program of small molecule antagonists of PD1 and VISTA immune checkpoint pathways. The development candidate is CA-170, an orally available small molecule antagonist of VISTA and PDL1. 3. PD1/TIM3 Program - an immuno-oncology program of small molecule antagonists of PD1 and TIM3 immune checkpoint pathways. The development candidate is CA-327, an orally available small molecule antagonist of PDL1 and TIM3. 4. In March 2018, the Company exercised its option to license a fourth program, which is an immuno-oncology program. For each of the licensed programs (as described above) the Company is obligated to use commercially reasonable efforts to develop, obtain regulatory approval for, and commercialize at least one product in each of the U.S., specified countries in the European Union and Japan, and Aurigene is obligated to use commercially reasonable efforts to perform its obligations under the development plan for such licensed program in an expeditious manner. For each of the IRAK4, PD1/VISTA, and PD1/TIM3 programs, and the fourth immuno-oncology program: the Company has remaining unpaid or unwaived payment obligations of $42.5 million per program, related to regulatory approval and commercial sales milestones, plus specified additional payments for approvals for additional indications, if any. The Company has not recorded a liability for the aforementioned payments given the achievement of specified regulatory approval and commercial sales milestones is not probable as of the balance sheet date. The Company is further obligated to pay Aurigene tiered royalties on the Company's and its affiliates' annual net sales of products at percentage rates ranging from the high single digits up to 10%, subject to specified reductions. In addition, the Company agreed to make certain payments to Aurigene upon its entry into sublicense agreements on any program(s). In addition to the collaboration agreement, the Company has entered into a master development and manufacturing agreement with Aurigene for the supply of drug substance and drug product. Under this agreement, the Company incurred less than $0.1 million in research and development expense during the three and six months ended June 30, 2022. The Company incurred $0.4 million in research and development expense during the three months ended June 30, 2021 and $0.8 million during the six months ended June 30, 2021 associated with this agreement. The Company recorded no prepaid expenses and no accrued expenses associated with this agreement as of June 30, 2022 and as of December 31, 2021. (c) ImmuNext The Company has entered into an option and license agreement with ImmuNext (the “ImmuNext Agreement”). Under the terms of the ImmuNext Agreement, the Company agreed to engage in a collaborative effort with ImmuNext, and to conduct a Phase 1 clinical trial of CI-8993. In exchange, ImmuNext granted the Company an exclusive option, exercisable until the earlier of January 2024 or (b) 90 days after database lock for the first Phase 1 trial in which the endpoints are satisfied (the “Option Period”), to obtain an exclusive, worldwide license to develop and commercialize certain VISTA antagonizing compounds and products containing these compounds in the field of oncology. During the Option Period, the Company is obligated to pay a semi-annual fee of $0.4 million to ImmuNext and will conduct the Phase 1 trial, and ImmuNext will conduct certain agreed upon non-clinical research activities to support the Phase 1 trial. Additionally, the Company will assign to ImmuNext all right, title and interest in and to, inventions made by the Company alone or jointly with ImmuNext in conducting clinical and non-clinical activities under the ImmuNext Agreement and any patent rights covering those inventions. If the option is exercised, ImmuNext will assign to the Company (i) all such inventions that were made solely by the Company and any patent rights covering those inventions that were assigned by the Company to ImmuNext during the Option Period and (ii) a joint ownership interest in all such inventions that were made jointly by the Company and ImmuNext and patent rights covering those inventions that were assigned by the Company to ImmuNext during the Option Period, except for any of those inventions that relates to certain compounds to which ImmuNext has retained exclusive rights. In addition, the Company has agreed to reimburse ImmuNext for certain documented external costs and expenses incurred by ImmuNext in carrying out non-clinical research activities approved by the joint steering committee, up to $0.3 million per calendar year, unless otherwise agreed to by both parties in writing. If the Company elects to exercise the option, the Company has agreed to pay to ImmuNext an option exercise fee of $20.0 million. ImmuNext will be eligible to receive up to $4.6 million in potential development milestones, up to $84.3 million in potential regulatory approval milestones, and up to $125.0 million in potential sales milestone payments from the Company. ImmuNext is also eligible to receive tiered royalties on annual net sales on a product-by-product and country-by-country basis, at percentage rates ranging from high single digits to low double digits, subject to specified adjustments. In addition, the Company has agreed to pay ImmuNext a low double-digit percentage of sublicense revenue received by the Company or its affiliates.

Common Stock

Common Stock	6 Months Ended
	Jun. 30, 2022
Equity [Abstract]
Common Stock	Common Stock (a) Charter Amendments In May 2021, the Company's stockholders approved an increase to the number of authorized shares of its common stock from 151,875,000 shares to 227,812,500 shares. The Company filed an amendment to its certificate of incorporation in May 2021 to effect such increase. (b) 2021 Sales Agreement with Cantor Fitzgerald & Co. and JonesTrading Institutional Services LLC In March 2021, the Company entered into a sales agreement (the “2021 Sales Agreement”) with Cantor Fitzgerald & Co., or Cantor, and JonesTrading Institutional Services LLC , or JonesTrading, to sell from time to time up to $100.0 million of the Company’s common stock through an “at the market offering” program under which Cantor and JonesTrading act as sales agents. Subject to the terms and conditions of the 2021 Sales Agreement, Cantor and JonesTrading can sell the common stock by any method deemed to be an “at-the-market” offering as defined in Rule 415 promulgated under the Securities Act of 1933, as amended (the “Securities Act”). Pursuant to the terms of the 2021 Sales Agreement, the aggregate compensation payable to each of Cantor and JonesTrading is 3% of the gross proceeds from sales of the common stock sold by Cantor or JonesTrading, as applicable. Each party agreed in the 2021 Sales Agreement to provide indemnification and contribution against certain liabilities, including liabilities under the Securities Act, subject to the terms of the 2021 Sales Agreement. To date, the Company has not made any sales of common stock pursuant to the 2021 Sales Agreement. (c) Aspire Capital Fund LLC In February 2020, the Company entered into a common stock purchase agreement (the “Agreement”) with Aspire Capital Fund, LLC (“Aspire Capital”) for the sale of up to $30.0 million of the Company's common stock. Under the terms of the Agreement, Aspire Capital has committed to purchase such shares of the Company's common stock at the Company’s request, from time to time during a 30-month period at prices based on the market price at the time of each sale, subject to specified terms and limitations. Aspire Capital made an initial investment of $3.0 million through the purchase of 2,693,965 shares of the Company's common stock. In 2020, Aspire Capital subsequently purchased an additional 4,650,000 shares of the Company's common stock for $5.4 million. In addition, as consideration for Aspire Capital’s obligation under the Agreement, the Company issued 646,551 shares of common stock to Aspire Capital as a commitment fee. As of June 30, 2022 and December 31, 2021, a total of $21.6 million remained available under the Agreement. The Company did not sell shares of common stock under the Agreement during the three and six months ended June 30, 2022 and June 30, 2021. Under the terms of the Agreement, the Company has the right to sell up to 150,000 shares of common stock per day to Aspire Capital, which total may be increased by mutual agreement up to an additional 2,000,000 shares per day. The extent to which the Company relies on Aspire Capital as a source of funding will depend on a number of factors, including the prevailing market price of its common stock and the extent to which it is able to secure working capital from other sources. There are no warrants, derivatives, or other share classes associated with this Agreement. The Company will control the timing and amount of the further sale of its common stock to Aspire Capital. There are no restrictions on future financings and there are no financial covenants, participation rights, rights of first refusal, or penalties in the Agreement. The Company has the right to terminate the Agreement at any time without any additional cost or penalty.

Stock Plans and Stock Based Com

Stock Plans and Stock Based Compensation	6 Months Ended
	Jun. 30, 2022
Share-Based Payment Arrangement [Abstract]
Stock Plans and Stock Based Compensation	Stock Plans and Stock-Based Compensation As of June 30, 2022, the Company had two shareholder-approved, stock-based compensation plans: (i) the Amended and Restated 2010 Employee Stock Purchase Plan (“ESPP”), adopted by the Board of Directors in April 2017 and approved by shareholders in June 2017, and (ii) the Fourth Amended and Restated 2010 Stock Incentive Plan (“2010 Plan”). New employees are typically issued options as an inducement equity award under Nasdaq Listing Rule 5635(c)(4) outside of the 2010 Plan. The Fourth Amended and Restated 2010 Stock Incentive Plan The 2010 Plan permits the granting of incentive and non-qualified stock options and stock awards to employees, officers, directors, and consultants of the Company and its subsidiaries at prices determined by the Company’s Board of Directors. In May 2021, the Company's shareholders approved the Company's Fourth Amended and Restated 2010 Stock Incentive Plan to reserve an additional 11,000,000 shares of common stock for issuance under the 2010 Plan. The Company can issue up to 23,190,000 shares of its common stock pursuant to awards granted under the 2010 Plan. Options become exercisable as determined by the Board of Directors and expire up to ten years from the date of grant. The 2010 Plan uses a “fungible share” concept under which each share of stock subject to awards granted as options and stock appreciation rights (“SARs”), will cause one share per share under the award to be removed from the available share pool, while each share of stock subject to awards granted as restricted stock, restricted stock units, other stock-based awards or performance awards where the price charged for the award is less than 100% of the fair market value of the Company’s common stock will cause 1.3 shares per share under the award to be removed from the available share pool. As of June 30, 2022, the Company has only granted options to purchase shares of the Company’s common stock with an exercise price equal to the closing market price of the Company’s common stock on the Nasdaq Global Market on the grant date. As of June 30, 2022, 9,829,897 shares remained available for grant under the 2010 Plan. Stock Options During the six months ended June 30, 2022, the Company’s board of directors granted options to purchase 3,663,800 shares of the Company’s common stock to the officers and employees of the Company under the 2010 Plan. Shares granted to officers and employees vest as to 25% of the shares underlying the award on the first anniversary of the grant date and as to an additional 6.25% of the shares underlying the award at the end of each subsequent quarter, based upon continued employment over a four year period, and are exercisable at a price equal to the closing price of the Company’s common stock on the Nasdaq Global Market on the grant date. During the six months ended June 30, 2022, the Company’s board of directors granted options to its non-employee directors to purchase 425,000 shares of common stock under the 2010 Plan, which will vest and become exercisable one year from the grant date. In addition, during the six months ended June 30, 2022, the Company's board of directors issued options to newly-hired employees as an inducement equity award under Nasdaq Listing Rule 5635(c)(4) outside of the 2010 Plan to purchase 605,550 shares of common stock. These options will vest as to 25% of the shares underlying the option on the first anniversary of the grant date, and as to an additional 6.25% of the shares underlying the option on each successive three-month period thereafter. All option awards are exercisable at a price equal to the closing price of the Company’s common stock on the Nasdaq Global Market on the grant dates. A summary of stock option activity under the 2010 Plan and inducement awards are summarized as follows: Number of Weighted Weighted Aggregate Intrinsic Value Outstanding, December 31, 2021 10,363,769 $ 3.80 7.41 Granted 4,694,350 3.14 Exercised — — Canceled/Forfeited (472,820) 7.29 Outstanding, June 30, 2022 14,585,299 $ 3.47 7.73 $ 19 Exercisable at June 30, 2022 7,398,636 $ 3.32 6.55 $ 11 Vested and unvested expected to vest at June 30, 2022 13,783,730 $ 3.46 7.64 $ 18 The weighted average grant date fair values of the stock options granted during the six months ended June 30, 2022 and 2021 were $2.57 and $9.42, respectively, and were calculated using the following estimated assumptions: Six Months Ended 2022 2021 Expected term (years) 5.5 5.5 Risk free interest rate 1.4-2.5% 0.4-1.4% Expected Volatility 110%-112% 107 % Expected Dividends None None As of June 30, 2022, there was approximately $16.3 million of unrecognized compensation cost related to unvested employee stock option awards outstanding, net of the impact of estimated forfeitures that is expected to be recognized as expense over a weighted average period of 2.64 years. There were no employee stock options exercised during the six months ended June 30, 2022. The intrinsic value of employee stock options exercised during the six months ended June 30, 2021 was insignificant. Restricted Stock Awards The following table presents a summary of unvested restricted stock awards (“RSAs”) under the 2010 Plan as of June 30, 2022: Number of Weighted Unvested, December 31, 2021 10,312 $ 3.45 Awarded — — Vested (10,312) 3.45 Forfeited — — Unvested, June 30, 2022 — $ — As of June 30, 2022, there were no outstanding RSAs. Amended and Restated 2010 Employee Stock Purchase Plan The Company has reserved 2,000,000 shares of common stock for issuance under the ESPP. Eligible employees may purchase shares of the Company’s common stock at 85% of the lower closing market price of the common stock at the beginning of the enrollment period or ending date of the purchase period within a two-year enrollment period, as defined. The Company has four six-month purchase periods per each two-year enrollment period. If, within any one of the four purchase periods in an enrollment period, the purchase period ending stock price is lower than the stock price at the beginning of the enrollment period, the two-year enrollment resets at the new lower stock price. This aspect of the plan was amended in 2017. Prior to 2017, the plan included two six-month purchase periods per year with no defined enrollment period. During the three and six months ended June 30, 2022, 169,296 shares were issued under the ESPP. As of June 30, 2022, there were 1,384,234 shares available for future purchase under the ESPP. ESPP compensation expense for the three and six months ended June 30, 2022 and 2021 was insignificant. Total Stock-Based Compensation Expense For the three and six months ended June 30, 2022 and 2021, the Company recorded stock-based compensation expense to the following line items in its costs and expenses section of the Condensed Consolidated Statements of Operations and Comprehensive Loss, including expense related to its ESPP: Three Months Ended Six Months Ended (in thousands) 2022 2021 2022 2021 Research and development expenses $ 854 $ 440 $ 1,579 $ 778 General and administrative expenses 1,112 835 2,105 1,596 Total stock-based compensation expense $ 1,966 $ 1,275 $ 3,684 $ 2,374

Loss Per Common Share

Loss Per Common Share	6 Months Ended
	Jun. 30, 2022
Earnings Per Share [Abstract]
Loss Per Common Share	Loss Per Common ShareBasic and diluted loss per common share is computed by dividing net loss attributable to common stockholders by the weighted average number of common shares outstanding during the period. Diluted net loss per common share is the same as basic net loss per common share for the three and six months ended June 30, 2022 and 2021, because the effect of the potential common stock equivalents would be antidilutive due to the Company’s net loss position for these periods. Antidilutive securities consist of stock options outstanding of 14,585,299 and 10,054,525 as of June 30, 2022 and 2021, respectively.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation and Principles of Consolidation	Basis of Presentation and Principles of ConsolidationThe accompanying Condensed Consolidated Financial Statements have been prepared in accordance with the instructions to Form 10-Q and Rule 10-01 of Regulation S-X. These statements, however, are condensed and do not include all disclosures required by accounting principles generally accepted in the U.S. (“GAAP”), for complete financial statements and should be read in conjunction with the Company’s Annual Report on Form 10-K for the year ended December 31, 2021 as filed with the Securities and Exchange Commission (“SEC”), on February 24, 2022.
Use of Estimates and Assumptions	Use of Estimates and Assumptions The preparation of the Company’s Condensed Consolidated Financial Statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts and disclosure of certain assets and liabilities at the balance sheet date. Such estimates include the performance obligations under the Company’s collaboration agreements; the estimated repayment term of the Company’s debt and related short- and long-term classification; the collectability of receivables; the carrying value of property and equipment and goodwill; and the assumptions used in the Company’s valuation of stock-based compensation and the value of certain investments and liabilities. Actual results may differ from such estimates. These interim results are not necessarily indicative of results to be expected for a full year or subsequent interim periods. The extent to which COVID-19 has had and may continue to have impacts on the Company’s business and financial results will depend on numerous evolving factors including, but not limited to: the magnitude and duration of the continuing COVID-19 pandemic, the extent to which it has impacted and may continue to impact worldwide macroeconomic conditions including interest rates, employment rates and health insurance coverage, the speed of the anticipated recovery, and governmental and business responses to the pandemic. The Company assessed certain accounting matters that generally require consideration of forecasted financial information in context with the information reasonably available to the Company and the unknown future impacts of COVID-19 as of June 30, 2022 and through the date of this report. The Company’s future assessment of the magnitude and duration of the COVID-19 pandemic, as well as other factors, could result in material impacts to the Company’s consolidated financial statements in future reporting periods.
Cash Equivalents, Restricted Cash, and Investments	Cash Equivalents, Restricted Cash, and InvestmentsCash equivalents consist of highly liquid investments purchased with original maturities of three months or less. All other liquid investments are classified as marketable securities. The Company classified $0.6 million and $0.7 million of its cash as restricted cash as June 30, 2022 and December 31, 2021, respectively. This amount represents the security deposit on the Company's current Massachusetts headquarters. The Company's combined cash and cash equivalents and restricted cash balances were $34.6 million and $75.8 million as of June 30, 2022 and June 30, 2021, respectively, as presented on the Company's Condensed Consolidated Statements of Cash Flows. The Company’s short-term investments are marketable debt securities with original maturities of greater than three months from the date of purchase, but less than twelve months from the balance sheet date, and long-term investments are marketable debt securities with original maturities of greater than twelve months from the balance sheet date. Marketable securities consist of commercial paper, corporate bonds and notes, and/or government obligations. All of the Company’s investments have been designated available-for-sale and are stated at fair value. Unrealized gains and temporary losses on investments are included in accumulated other comprehensive income (loss) as a separate component of stockholders’ equity (deficit). Realized gains and losses, dividends and interest income are included in other income (expense) in the period during which the securities are sold. Any premium or discount arising at purchase is amortized and/or accreted to interest income. Accrued interest receivable related to the Company's available-for-sale debt securities is presented within investments on the Company's consolidated balance sheets. Any write offs of accrued interest receivable are recorded by reversing interest income, recognizing credit loss expense, or a combination of both. To date, the Company has not written off any accrued interest receivables associated with its marketable securities.
Leases	Leases The Company determines if an arrangement is a lease at contract inception. Operating lease assets represent the Company's right to use an underlying asset for the lease term and operating lease liabilities represent its obligation to make lease payments arising from the lease. Operating lease assets and liabilities are recognized at the commencement date of the lease based upon the present value of lease payments over the lease term. When determining the lease term, the Company includes options to extend or terminate the lease when it is reasonably certain that the Company will exercise that option. As the Company's lease does not provide an implicit interest rate, the Company uses its incremental borrowing rate, which is based on rates that would be incurred to borrow on a collateralized basis over a term equal to the lease payments in a similar economic environment, in determining the present value of lease payments. Right-of-use assets and lease liabilities are recognized at the lease commencement date based on the present value of lease payments over the lease term. The lease payment used to determine the operating lease asset may include lease incentives, stated rent increases and was recognized as an operating lease right-of-use asset in the Condensed Consolidated Balance Sheets. The Company's lease agreements may include both lease and non-lease components, which are accounted for as a single lease component when the payments are fixed. Variable payments included in the lease agreement are expensed as incurred.
Revenue Recognition	Revenue Recognition The Company’s business strategy includes entering into collaborative license and development agreements with biotechnology and pharmaceutical companies for the development and commercialization of the Company’s drug candidates. The terms of the agreements typically include non-refundable license fees, funding of research and development, payments based upon achievement of clinical development and regulatory objectives, and royalties on product sales. License Fees and Multiple Element Arrangements If a license to its intellectual property is determined to be distinct from the other performance obligations identified in the arrangement, the Company will recognize revenues from non-refundable, up-front fees allocated to the license at such time as the license is transferred to the licensee and the licensee is able to use, and benefit from, the license. For licenses that are bundled with other promises, the Company utilizes judgment to assess the nature of the combined performance obligation to determine whether the combined performance obligation is satisfied over time or at a point in time and, if over time, the appropriate method of measuring progress for purposes of recognizing revenue from non-refundable, up-front fees. The Company evaluates the measure of progress each reporting period and, if necessary, will adjust the measure of performance and related revenue recognition. If the Company is involved in a steering committee as part of a multiple element arrangement, the Company assesses whether its involvement constitutes a performance obligation or a right to participate. Steering committee services that are not determined to be distinct performance obligations are combined with other research services or performance obligations required under an arrangement, if any, in determining the level of effort required in an arrangement and the period over which the Company expects to complete its aggregate performance obligations. Appropriate methods of measuring progress include output methods and input methods. In determining the appropriate method for measuring progress, the Company considers the nature of service that it promises to transfer to the customer. When the Company decides on a method of measurement, the Company will apply that single method of measuring progress for each performance obligation satisfied over time and will apply that method consistently to similar performance obligations and in similar circumstances. If the Company cannot reasonably measure its progress toward complete satisfaction of a performance obligation because the Company lacks reliable information that would be required to apply an appropriate method of measuring progress, but it can reasonably estimate when the performance ceases or the remaining obligations become inconsequential and perfunctory, then revenue is not recognized until the Company can reasonably estimate when the performance obligation ceases or becomes inconsequential. Revenue is then recognized over the remaining estimated period of performance. Significant management judgment is required in determining the level of effort required under an arrangement and the period over which the Company is expected to complete its performance obligations under an arrangement. Contingent Research Milestone Payments Accounting Standards Codification ("ASC") 606 constrains the amount of variable consideration included in the transaction price in that either all, or a portion, of an amount of variable consideration should be included in the transaction price. The variable consideration amount should be included only to the extent that it is probable that a significant reversal in the amount of cumulative revenue recognized will not occur when the uncertainty associated with the variable consideration is subsequently resolved. The assessment of whether variable consideration should be constrained is largely a qualitative one that has two elements: the likelihood of a change in estimate, and the magnitude thereof. Variable consideration is not constrained if the potential reversal of cumulative revenue recognized is not significant, for example. If the consideration in a contract includes a variable amount, a company will estimate the amount of consideration in exchange for transfer of promised goods or services. The consideration also can vary if a company’s entitlement to the consideration is contingent on the occurrence or nonoccurrence of a future event. The Company considers contingent research milestone payments to fall under the scope of variable consideration, which should be estimated for revenue recognition purposes at the inception of the contract and reassessed ongoing at the end of each reporting period. The Company assesses whether contingent research milestones should be considered variable consideration that should be constrained and thus not part of the transaction price. This includes an assessment of the probability that all or some of the milestone revenues could be reversed when the uncertainty around whether or not the achievement of each milestone is resolved, and the amount of reversal could be significant. GAAP provides factors to consider when assessing whether variable consideration should be constrained. All of the factors should be considered, and no factor is determinative. The Company considers all relevant factors. Reimbursement of Costs Reimbursement of research and development costs by third-party collaborators is recognized as revenue over time provided the Company has determined that it transfers control (i.e. performs the services) of a service over time and, therefore, satisfies a performance obligation according to the provisions outlined in ASC 606-10-25-27, Revenue Recognition . Royalty Revenue The Company recognizes royalty revenues related to Genentech’s and Roche’s sales of Erivedge. For arrangements that include sales-based royalties, including milestone payments based on the level of sales, and where the license is deemed to be the predominant item to which the royalties relate, the Company recognizes revenue at the later of (i) when the related sales occur, or (ii) when the performance obligation to which some or all of the royalty has been allocated has been satisfied (or partially satisfied). The Company expects to continue recognizing royalty revenue from Genentech’s sales of Erivedge in the U.S. and in other markets where Genentech and Roche successfully obtain marketing approval, if any (see Note 9, Research and Development Collaborations ). However, a portion of potential Erivedge royalties will be paid to the Purchasers pursuant to the Oberland Purchase Agreement (see Note 8, Liability Related to the Sale of Future Royalties ). Contra Revenue, Net Contra revenue, net represents shared costs, primarily related to intellectual property, with the Company's collaboration partners. With respect to each of the foregoing areas of revenue recognition, the Company exercises significant judgment in determining whether an arrangement contains multiple elements, and, if so, how much revenue is allocable to each element. In addition, the Company exercises its judgment in determining when its significant obligations have been met under such agreements and the specific time periods over which the Company recognized revenue, such as non-refundable, up-front license fees. To the extent that actual facts and circumstances differ from the Company's initial judgments, its revenue recognition with respect to such transactions would change accordingly and any such change could affect the Company's reported financial results.
Segment Reporting	Segment ReportingThe Company operates in a single reportable segment, which is the research and development of innovative cancer therapies.
New Accounting Pronouncements	New Accounting PronouncementsThe Company considers the applicability and impact of any recent Accounting Standards Update (“ASU”) issued by the Financial Accounting Standards Board (“FASB”). Based on the assessment, the ASUs were determined to be either not applicable or are expected to have minimal impact on the Company's condensed consolidated financial statements.
Fair Value Measurements	Fair Value of Financial Instruments The Company has adopted the provisions of the FASB Codification Topic 820, Fair Value Measurements and Disclosures (“Topic 820”) for its financial assets and liabilities that are re-measured and reported at fair value each reporting period and the non-financial assets and liabilities that are re-measured and reported at fair value on a non-recurring basis. Fair value is the price that would be received from selling an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. When determining fair value, the Company considers the principal or most advantageous market in which it would transact and consider assumptions that market participants would use when pricing the asset or liability. Topic 820 establishes a three-level valuation hierarchy for disclosure of fair value measurements. Financial assets and liabilities are categorized within the valuation hierarchy based upon the lowest level of input that is significant to the measurement of fair value. The three levels of the hierarchy are defined as follows: Level 1 Quoted prices in active markets for identical assets or liabilities. Level 2 Observable inputs other than Level 1 prices, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. Level 3 Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities.

Fair Value of Financial Instr_2

Fair Value of Financial Instruments (Tables)	6 Months Ended
	Jun. 30, 2022
Fair Value Disclosures [Abstract]
Schedule of Financial Assets or Liabilities Measured at Fair Value on Recurring Basis	In accordance with the fair value hierarchy, the following table shows the fair value as of June 30, 2022 and December 31, 2021 of those financial assets and liabilities that are measured at fair value on a recurring basis, according to the valuation techniques the Company used to determine their fair value. No financial assets or liabilities are measured at fair value on a nonrecurring basis at June 30, 2022 and December 31, 2021. (in thousands) Quoted Prices in Other Observable Unobservable Fair Value As of June 30, 2022: Cash equivalents: Money market funds $ 31,371 $ — $ — $ 31,371 Short-term investments: Corporate commercial paper, bonds and notes — 73,192 — 73,192 Total $ 31,371 $ 73,192 $ — $ 104,563 (in thousands) Quoted Prices in Other Observable Unobservable Fair Value As of December 31, 2021: Cash equivalents: Money market funds $ 33,944 $ — $ — $ 33,944 Short-term investments: Corporate commercial paper, bonds and notes — 75,870 — 75,870 Long-term investments: Corporate commercial paper, bonds and notes — 23,964 — 23,964 Total $ 33,944 $ 99,834 $ — $ 133,778

Investments (Tables)

Investments (Tables)	6 Months Ended
	Jun. 30, 2022
Investments, Debt and Equity Securities [Abstract]
Schedule of Amortized Cost of Unrealized Gains and Losses and Fair Value of Investments	The amortized cost, including interest receivable, unrealized gains and losses and fair value of investments available-for-sale as of June 30, 2022 are as follows: (in thousands) Amortized Unrealized Unrealized Fair Value Corporate bonds and notes—short-term $ 73,747 $ — $ (555) $ 73,192 Total investments $ 73,747 $ — $ (555) $ 73,192 The amortized cost, including interest receivable, unrealized gains and losses and fair value of investments available-for-sale as of December 31, 2021 are as follows: (in thousands) Amortized Unrealized Unrealized Fair Value Corporate bonds and notes—short-term $ 75,896 $ — $ (26) $ 75,870 Corporate bonds and notes—long-term 24,047 — (83) 23,964 Total investments $ 99,943 $ — $ (109) $ 99,834

Accrued Liabilities (Tables)

Accrued Liabilities (Tables)	6 Months Ended
	Jun. 30, 2022
Other Liabilities Disclosure [Abstract]
Schedule of Accrued Liabilities	Accrued liabilities consisted of the following: (in thousands) June 30, 2022 December 31, 2021 Compensation and related costs $ 2,708 $ 3,260 Chemistry, manufacturing and controls costs 1,515 2,232 Professional and legal fees 828 644 Other 524 203 Total $ 5,575 $ 6,339

Liability Related to the Sale_2

Liability Related to the Sale of Future Royalties (Tables)	6 Months Ended
	Jun. 30, 2022
Nonmonetary Transactions [Abstract]
Schedule of Liability Due to Non-Cash Transaction	The following table shows the activity with respect to the liability related to the sale of future royalties during the six months ended June 30, 2022. (in thousands) Carrying value of liability related to the sale of future royalties at January 1, 2022 $ 53,798 Amortization of capitalized issuance costs 31 Imputed interest expense recognized for the six months ending June 30, 2022 2,065 Less: payments to Oberland Capital, LLC (4,646) Carrying value of liability related to the sale of future royalties at June 30, 2022 $ 51,248

Stock Plans and Stock Based C_2

Stock Plans and Stock Based Compensation (Tables)	6 Months Ended
	Jun. 30, 2022
Share-Based Payment Arrangement [Abstract]
Summary of Stock Option Activity	A summary of stock option activity under the 2010 Plan and inducement awards are summarized as follows: Number of Weighted Weighted Aggregate Intrinsic Value Outstanding, December 31, 2021 10,363,769 $ 3.80 7.41 Granted 4,694,350 3.14 Exercised — — Canceled/Forfeited (472,820) 7.29 Outstanding, June 30, 2022 14,585,299 $ 3.47 7.73 $ 19 Exercisable at June 30, 2022 7,398,636 $ 3.32 6.55 $ 11 Vested and unvested expected to vest at June 30, 2022 13,783,730 $ 3.46 7.64 $ 18 The weighted average grant date fair values of the stock options granted during the six months ended June 30, 2022 and 2021 were $2.57 and $9.42, respectively, and were calculated using the following estimated assumptions: Six Months Ended 2022 2021 Expected term (years) 5.5 5.5 Risk free interest rate 1.4-2.5% 0.4-1.4% Expected Volatility 110%-112% 107 % Expected Dividends None None
Nonvested Restricted Stock Shares Activity	The following table presents a summary of unvested restricted stock awards (“RSAs”) under the 2010 Plan as of June 30, 2022: Number of Weighted Unvested, December 31, 2021 10,312 $ 3.45 Awarded — — Vested (10,312) 3.45 Forfeited — — Unvested, June 30, 2022 — $ —
Schedule of Share Based Compensation Allocation of Recognized Period Costs	For the three and six months ended June 30, 2022 and 2021, the Company recorded stock-based compensation expense to the following line items in its costs and expenses section of the Condensed Consolidated Statements of Operations and Comprehensive Loss, including expense related to its ESPP: Three Months Ended Six Months Ended (in thousands) 2022 2021 2022 2021 Research and development expenses $ 854 $ 440 $ 1,579 $ 778 General and administrative expenses 1,112 835 2,105 1,596 Total stock-based compensation expense $ 1,966 $ 1,275 $ 3,684 $ 2,374

Nature of Business (Details)

Nature of Business (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Accumulated deficit	$ 1,124,374				$ 1,124,374		$ 1,092,325
Net loss	15,940	$ 16,109	$ 10,838	$ 9,927	32,049	$ 20,765
Cash used in operations					28,947	$ 19,838
Cash, cash equivalents, and investments	$ 107,200				$ 107,200

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022 USD ($)	Jun. 30, 2021 USD ($)	Jun. 30, 2022 USD ($) segment	Jun. 30, 2021 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Restricted cash	$ 600		$ 600		$ 700
Cash and cash equivalents, restricted cash and restricted cash equivalents	$ 34,643	$ 75,842	$ 34,643	$ 75,842	$ 40,740	$ 130,426
Number of reportable segments | segment			1
Customer Concentration Risk | Genentech, Inc. | Revenue Benchmark
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Concentration risk	100%	99%	100%	99%

Fair Value of Financial Instr_3

Fair Value of Financial Instruments - (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Short-term investments:
Total	$ 104,563	$ 133,778
Corporate commercial paper, bonds and notes
Short-term investments:
Short-term investments:	73,192	75,870
Long-term investments:		23,964
Money market funds
Cash equivalents:
Money market funds	31,371	33,944
Quoted Prices in Active Markets (Level 1)
Short-term investments:
Total	31,371	33,944
Quoted Prices in Active Markets (Level 1) | Corporate commercial paper, bonds and notes
Short-term investments:
Short-term investments:	0	0
Long-term investments:		0
Quoted Prices in Active Markets (Level 1) | Money market funds
Cash equivalents:
Money market funds	31,371	33,944
Other Observable Inputs (Level 2)
Short-term investments:
Total	73,192	99,834
Other Observable Inputs (Level 2) | Corporate commercial paper, bonds and notes
Short-term investments:
Short-term investments:	73,192	75,870
Long-term investments:		23,964
Other Observable Inputs (Level 2) | Money market funds
Cash equivalents:
Money market funds	0	0
Unobservable Inputs (Level 3)
Short-term investments:
Total	0	0
Unobservable Inputs (Level 3) | Corporate commercial paper, bonds and notes
Short-term investments:
Short-term investments:	0	0
Long-term investments:		0
Unobservable Inputs (Level 3) | Money market funds
Cash equivalents:
Money market funds	$ 0	$ 0

Investments - Amortized Cost of

Investments - Amortized Cost of Unrealized Gains and Losses and Fair Value of Investments (Details) - USD ($)	6 Months Ended	12 Months Ended
	Jun. 30, 2022	Dec. 31, 2021	Jun. 30, 2021
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 73,747,000	$ 99,943,000
Unrealized Gain	0	0
Unrealized Loss	(555,000)	(109,000)
Fair Value	$ 73,192,000	$ 99,834,000
Weighted-average maturity of short-term investments	6 months	4 months 24 days
Debt securities, available-for-sale, credit loss	$ 0		$ 0
Corporate bonds and notes—short-term | Minimum
Debt Securities, Available-for-sale [Line Items]
Range of maturities	1 month	1 month
Corporate bonds and notes—short-term | Maximum
Debt Securities, Available-for-sale [Line Items]
Range of maturities	12 months	12 months
Corporate bonds and notes—long-term
Debt Securities, Available-for-sale [Line Items]
Weighted-average maturity of short-term investments		1 year 2 months 12 days
Corporate Debt Securities | Corporate bonds and notes—short-term
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 73,747,000	$ 75,896,000
Unrealized Gain	0	0
Unrealized Loss	(555,000)	(26,000)
Fair Value	$ 73,192,000	75,870,000
Corporate Debt Securities | Corporate bonds and notes—long-term
Debt Securities, Available-for-sale [Line Items]
Amortized Cost		24,047,000
Unrealized Gain		0
Unrealized Loss		(83,000)
Fair Value		$ 23,964,000

Accrued Liabilities - (Details)

Accrued Liabilities - (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Other Liabilities Disclosure [Abstract]
Compensation and related costs	$ 2,708	$ 3,260
Chemistry, manufacturing and controls costs	1,515	2,232
Professional and legal fees	828	644
Other	524	203
Total	$ 5,575	$ 6,339

Debt (Details)

Debt (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Apr. 30, 2020
Debt Instrument [Line Items]
Unsecured loan				$ 900
Gain on extinguishment of debt		$ 0	$ 890
Cares Act PPP Loan
Debt Instrument [Line Items]
Gain on extinguishment of debt	$ 900		$ 900
Silicon Valley Bank | Cares Act PPP Loan | Commercial Paper
Debt Instrument [Line Items]
Unsecured loan term				24 months
Unsecured loan interest rate				1%

Lease (Details)

Lease (Details) $ in Thousands	1 Months Ended	3 Months Ended			6 Months Ended
	Jan. 31, 2022 USD ($) ft² $ / ft²	Jun. 30, 2022 USD ($)	Mar. 31, 2022 USD ($)	Jun. 30, 2021 USD ($)	Jun. 30, 2022 USD ($)	Jun. 30, 2021 USD ($)	Dec. 31, 2021 USD ($)
Lessee, Lease, Description [Line Items]
Operating lease payments		$ 300		$ 300	$ 600	$ 1,700
Weighted average discount rate		9.95%			9.95%
Increase (decrease) in lease liability		$ 900	$ (1,100)		$ (191)	0
Increase (decrease) in operating lease right of use asset		900	$ (1,100)
Operating lease, liability		4,500			4,500		$ 5,000
Operating lease right-of-use asset		5,032			5,032		$ 5,749
Operating lease, expense		$ 400		300	$ 700	700
Remaining lease term		6 years			6 years
Lease obligations		$ 8,800			$ 8,800
One time payment, tenant improvements				$ 1,100		$ 1,100
128 Spring Street Lease Amendment
Lessee, Lease, Description [Line Items]
Area of real estate property | ft²	9,340
Area of existing space | $ / ft²	30
Operating lease payments	$ 300

Liability Related to the Sale_3

Liability Related to the Sale of Future Royalties - Narrative (Details) - USD ($) $ in Millions	1 Months Ended	6 Months Ended
	Mar. 31, 2019	Jun. 30, 2022
Nonmonetary Transaction [Line Items]
Non-cash interest rate	7.90%
Transaction fees	$ 0.6
Oberland Capital
Nonmonetary Transaction [Line Items]
Proceeds from royalty interest purchase agreement with Oberland Capital Management, LLC	65
Purchaser default option period		180 days
Oberland Capital | Aggregate Net Royalties Prior to 2027
Nonmonetary Transaction [Line Items]
Cash proceeds from royalty purchase agreement	53.5
Royalty amount threshold	$ 117

Liability Related to the Sale_4

Liability Related to the Sale of Future Royalties - Liability Due to Non-Cash Transaction (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2022 USD ($)
Nonmonetary Transaction [Roll Forward]
Carrying value of liability related to the sale of future royalties beginning balance	$ 53,798
Amortization of capitalized issuance costs	31
Imputed interest expense recognized	2,065
Less: payments to Oberland Capital, LLC	(4,646)
Carrying value of liability related to the sale of future royalties ending balance	$ 51,248

Research and Development Coll_2

Research and Development Collaborations (Details)	1 Months Ended	3 Months Ended		6 Months Ended
	Jun. 30, 2003 USD ($)	Jun. 30, 2022 USD ($)	Jun. 30, 2021 USD ($)	Jun. 30, 2022 USD ($) program	Jun. 30, 2021 USD ($)	Dec. 31, 2021 USD ($)	Feb. 29, 2020
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues, net		$ 2,393,000	$ 2,286,000	$ 4,450,000	$ 4,475,000
Cost of royalty revenues		42,000	116,000	124,000	225,000
Accounts receivable		2,395,000		$ 2,395,000		$ 3,224,000
Number of program licensed | program				4
Royalties
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues, net		2,474,000	2,348,000	$ 4,534,000	4,535,000
Genentech, Inc.
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Amount received for specified clinical development and regulatory objectives		59,000,000		59,000,000
Percentage of royalty rate decrease	2%
Cost of royalty revenues		100,000	100,000	100,000	200,000
Accounts receivable		2,400,000		2,400,000		3,200,000
Genentech, Inc. | Royalties
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues, net		2,500,000	2,300,000	4,500,000	4,500,000
Genentech, Inc. | Maximum
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Eligible to receive contingent cash milestone payments (up to)	$ 115,000,000
Percentage of royalty on net sales	7.50%
Genentech, Inc. | Minimum
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Percentage of royalty on net sales	5%
Aurigene | IRAK4, PD1/VISTA, and PD1/TIM3 Programs
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Waived payment of milestone and other payments (up to)				42,500,000
Aurigene | Master Development and Manufacturing Agreement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Prepaid expenses		0		0		0
Accrued expenses		0		0		$ 0
Aurigene | Master Development and Manufacturing Agreement | Research and Development Expense
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Collaborative arrangement payments agreement		$ 100,000	$ 400,000	$ 100,000	$ 800,000
Aurigene | Maximum
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Royalty fees receivable (as a percent)		10%		10%			10%
ImmuNext
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Semi-annual maintenance fee payments		$ 400,000		$ 400,000
ImmuNext | Maximum
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Maximum reimbursable expenses		300,000		300,000
Option exercise fee		20,000,000		20,000,000
Development milestone payments		4,600,000		4,600,000
Regulatory approval milestone payments		84,300,000		84,300,000
Sales milestone payments		$ 125,000,000		$ 125,000,000

Common Stock (Details)

Common Stock (Details) - USD ($)	1 Months Ended	12 Months Ended
	Feb. 29, 2020	Dec. 31, 2020	Jun. 30, 2022	Dec. 31, 2021	Jun. 30, 2021	May 31, 2021	Mar. 31, 2021
Class of Stock [Line Items]
Common stock authorized (in shares)			227,812,500	227,812,500		151,875,000
Common stock issued (in shares)			91,814,665	91,645,369
Value of shares of common stock issued			$ 918,000	$ 916,000
Aspire Capital Fund, LLC
Class of Stock [Line Items]
Stock purchase program price, period	30 months
Proceeds of aspire capital agreement, net of issuance costs	$ 3,000,000
Common stock issued (in shares)	2,693,965
Additional shares authorized under the plan (in shares)		4,650,000
Value of shares of common stock issued		$ 5,400,000
Common Stock
Class of Stock [Line Items]
Common stock authorized							$ 100,000,000
Compensation fee					3%
Common Stock | Aspire Capital Fund, LLC
Class of Stock [Line Items]
Authorized amount of stock repurchase	$ 30,000,000
Commitment fee (in shares)		646,551
Sale of stock remaining authorized amount			$ 21,600,000	$ 21,600,000
Stock purchase program, authorized per day (in shares)			150,000
Stock purchase program, authorized per day, after mutual agreement (in shares)			2,000,000

Stock Plans and Stock Based C_3

Stock Plans and Stock Based Compensation - Narrative (Details) $ / shares in Units, $ in Millions	1 Months Ended	3 Months Ended	6 Months Ended		12 Months Ended
	May 31, 2021 shares	Jun. 30, 2022 USD ($) shares	Jun. 30, 2022 USD ($) plan purchase_period $ / shares shares	Jun. 30, 2021 $ / shares	Dec. 31, 2016 purchase_period	Dec. 31, 2021 shares
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Number of shareholder-approved, share-based compensation plans | plan			2
Granted (in shares)			4,694,350
Weighted average grant-date fair values of stock options (in dollars per share) | $ / shares			$ 2.57	$ 9.42
Unrecognized compensation cost, net of estimated forfeitures | $		$ 16.3	$ 16.3
Unrecognized compensation cost, weighted average period for recognition			2 years 7 months 20 days
Intrinsic values of employee stock options exercised | $			$ 0
Outstanding shares (in shares)		0	0
Restricted Stock
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Vesting period (years)			4 years
Awarded (in shares)			0
Outstanding shares (in shares)		0	0			10,312
Restricted Stock | Officer
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Awarded (in shares)			605,550
Amended and Restated 2010 Stock Incentive Plan
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Shares authorized (in shares)	23,190,000
Number of shares under award to be removed from share pool			9,829,897
Amended and Restated 2010 Stock Incentive Plan | Employee Stock
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Additional shares authorized under the plan (in shares)	11,000,000
Amended and Restated 2010 Stock Incentive Plan | Stock Options, or Stock Appreciation Rights
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Period of time options are exercisable	10 years
Shares removed from pool (in shares per share)	1
Amended and Restated 2010 Stock Incentive Plan | Restricted Stock, RSUs, Other Stock-Based Awards, or Performance Awards
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Shares removed from pool (in shares per share)	1.3
Price charged for award based on fair market value percentage (less than)	100%
2010 Plan
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Granted (in shares)			3,663,800
2010 Plan | Non-Employee Directors
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Granted (in shares)			425,000
Vesting period (years)			1 year
2010 Plan | Tranche One
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Percentage of vested shares which are exercisable under stock option			25%
2010 Plan | Tranche Two
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Percentage of vested shares which are exercisable under stock option			6.25%
Employee Stock Purchase Plan
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Issuance of stock under Employee Stock Purchase Plan (in shares)		169,296	169,296
Employee Stock Purchase Plan | Employee Stock
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Shares authorized (in shares)		2,000,000	2,000,000
Price charged for award based on fair market value percentage (less than)			85%
Enrollment period			2 years
Number of purchase periods per year | purchase_period			4		2
Term of purchase periods			6 months		6 months
Shares available for future purchase under ESPP (in shares)		1,384,234	1,384,234

Stock Plans and Stock Based C_4

Stock Plans and Stock Based Compensation - Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2022	Dec. 31, 2021
Number of Shares
Beginning balance (in shares)	10,363,769
Granted (in shares)	4,694,350
Exercised (in shares)	0
Canceled/Forfeited (in shares)	(472,820)
Ending balance (in shares)	14,585,299	10,363,769
Exercisable at end of period (in shares)	7,398,636
Vested and unvested expected to vest at end of period (in shares)	13,783,730
Weighted Average Exercise Price per Share
Beginning balance (in dollars per share)	$ 3.80
Granted (in dollars per share)	3.14
Exercised (in dollars per share)	0
Canceled/Forfeited (in dollars per share)	7.29
Ending balance (in dollars per share)	3.47	$ 3.80
Exercisable at end of period (in dollars per share)	3.32
Vested and unvested expected to vest at end of period (in dollars per share)	$ 3.46
Weighted Average Remaining Contractual Life
Outstanding at end of period	7 years 8 months 23 days	7 years 4 months 28 days
Exercisable at end of period	6 years 6 months 18 days
Vested and unvested expected to vest at end of period	7 years 7 months 20 days
Aggregate Intrinsic Value
Outstanding at end of period	$ 19
Exercisable at end of period	11
Vested and unvested expected to vest at end of period	$ 18

Stock Plans and Stock Based C_5

Stock Plans and Stock Based Compensation - Key Assumptions (Details)	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Share-Based Payment Arrangement [Abstract]
Expected term	5 years 6 months	5 years 6 months
Risk -free Interest rate (minimum)	1.40%	0.40%
Risk -free Interest rate (maximum)	2.50%	1.40%
Expected volatility (minimum)	110%
Expected volatility (maximum)	112%
Expected volatility		107%

Stock Plans and Stock Based C_6

Stock Plans and Stock Based Compensation - Restricted Stock Award Activity (Details)	6 Months Ended
	Jun. 30, 2022 $ / shares shares
Number of Shares
Ending balance (in shares)	0
Restricted Stock
Number of Shares
Beginning balance (in shares)	10,312
Awarded (in shares)	0
Vested (in shares)	(10,312)
Forfeited (in shares)	0
Ending balance (in shares)	0
Weighted Average Grant Date Fair Value
Beginning balance (in dollars per share) | $ / shares	$ 3.45
Awarded (in dollars per share) | $ / shares	0
Vested (in dollars per share) | $ / shares	3.45
Forfeited (in dollars per share) | $ / shares	0
Ending balance (in dollars per share) | $ / shares	$ 0

Stock Plans and Stock Based C_7

Stock Plans and Stock Based Compensation - Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Total stock-based compensation expense	$ 1,966,000	$ 1,275	$ 3,684,000	$ 2,374
Research and development expenses
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Total stock-based compensation expense	854,000	440	1,579,000	778
General and administrative expenses
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Total stock-based compensation expense	$ 1,112,000	$ 835	$ 2,105,000	$ 1,596

Loss Per Common Share (Details)

Loss Per Common Share (Details) - shares	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Stock Options Outstanding
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities (in shares)	14,585,299	10,054,525