Curis (CRIS) 10-Q 4 May 23 2023 Q1 Quarterly report Financial data

Cover

Cover - shares	3 Months Ended
	Mar. 31, 2023	Apr. 27, 2023
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2023
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
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	true
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		96,617,898
Amendment Flag	false
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q1
Entity Central Index Key	0001108205
Current Fiscal Year End Date	--12-31
Security Exchange Name	NASDAQ

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 31,696	$ 19,658
Short-term investments	40,063	65,965
Accounts receivable	2,314	2,975
Prepaid expenses and other current assets	3,937	3,521
Total current assets	78,010	92,119
Property and equipment, net	625	689
Restricted cash, long-term	635	635
Operating lease right-of-use asset	4,076	4,401
Other assets	2,216	2,022
Goodwill	8,982	8,982
Total assets	94,544	108,848
Current liabilities:
Accounts payable	2,642	3,193
Accrued liabilities	4,246	5,679
Current portion of operating lease liability	1,181	1,141
Total current liabilities	8,069	10,013
Long-term operating lease liability	2,492	2,800
Liability related to the sale of future royalties, net	47,393	49,483
Total liabilities	57,954	62,296
Stockholders’ equity:
Common stock, $0.01 par value—227,812,500 shares authorized; 96,617,898 shares issued and outstanding at March 31, 2023; 227,812,500 shares authorized; 96,607,586 shares issued and outstanding at December 31, 2022	966	966
Additional paid-in capital	1,196,171	1,194,769
Accumulated deficit	(1,160,556)	(1,148,997)
Accumulated other comprehensive loss	9	(186)
Total stockholders’ equity	36,590	46,552
Total liabilities and stockholders’ equity	$ 94,544	$ 108,848

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) (Unaudited) - $ / shares	Mar. 31, 2023	Dec. 31, 2022
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)	96,617,898	96,607,586
Common stock outstanding (in shares)	96,617,898	96,607,586

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Revenues, net:
Revenues, net	$ 2,297	$ 2,057
Costs and expenses:
Cost of royalties	24	82
Research and development	9,140	11,435
General and administrative	4,760	5,673
Total operating expenses	13,924	17,190
Loss from operations	(11,627)	(15,133)
Other income (expense):
Interest income	652	80
Expense related to the sale of future royalties	(584)	(1,056)
Total other income (expense)	68	(976)
Net loss	$ (11,559)	$ (16,109)
Net loss per common share (basic ) (in dollars per share)	$ (0.12)	$ (0.18)
Net loss per common share (diluted) (in dollars per share)	$ (0.12)	$ (0.18)
Weighted average common shares (basic) (in shares)	96,613,544	91,645,369
Weighted average common shares (diluted) (in shares)	96,613,544	91,645,369
Net loss	$ (11,559)	$ (16,109)
Other comprehensive income:
Unrealized gain (loss) on marketable securities	195	(342)
Comprehensive loss	$ (11,364)	$ (16,451)

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Unaudited) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive (Loss) Income
Beginning balance (in shares) at Dec. 31, 2021		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]
Stock-based compensation	1,718		1,718
Unrealized gain 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, 2022	96,607,586	96,607,586
Beginning balance at Dec. 31, 2022	$ 46,552	$ 966	1,194,769	(1,148,997)	(186)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	1,395		1,395
Issuances of common stock under stock-based compensation plans (in shares)		10,312
Issuances of common stock under stock-based compensation plans	7		7
Unrealized gain on marketable securities	195				195
Net loss	$ (11,559)			(11,559)
Ending balance (in shares) at Mar. 31, 2023	96,617,898	96,617,898
Ending balance at Mar. 31, 2023	$ 36,590	$ 966	$ 1,196,171	$ (1,160,556)	$ 9

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Cash flows from operating activities:
Net loss	$ (11,559)	$ (16,109)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	64	36
Non-cash lease expense	324	239
Stock-based compensation expense	1,395	1,718
Non-cash expense related to the sale of future royalties	(77)	(18)
Net amortization of premiums and discounts on marketable securities	(145)	380
Changes in operating assets and liabilities:
Accounts receivable	661	1,164
Prepaid expenses and other assets	(610)	(158)
Accounts payable and accrued and other liabilities	(1,984)	(3,890)
Operating lease liability	(268)	(177)
Total adjustments	(640)	(706)
Net cash used in operating activities	(12,199)	(16,815)
Cash flows from investing activities:
Purchase of investments	(17,682)	(24,972)
Sales and maturities of investments	43,925	21,900
Purchases of property and equipment	0	(11)
Net cash provided by (used in) investing activities	26,243	(3,083)
Cash flows from financing activities:
Proceeds from issuance of common stock under employee benefit plans	7	0
Payment of liability of future royalties, net of imputed interest	(2,013)	(1,648)
Net cash provided by (used in) financing activities	(2,006)	(1,648)
Net decrease in cash and cash equivalents and restricted cash	12,038	(21,546)
Cash and cash equivalents and restricted cash, beginning of period	20,293	40,740
Cash and cash equivalents and restricted cash, end of period	32,331	19,194
Supplemental cash flow data:
Issuance costs in accrued expenses and accounts payable	0	172
Cash paid for interest	661	1,074
Decrease in right-of-use assets and operating lease liabilities resulting from lease modification	$ 0	$ (1,098)

Nature of Business

Nature of Business	3 Months Ended
	Mar. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of Business	Nature of Business Curis, Inc. is a biotechnology company seeking to develop and commercialize innovative drug candidates to treat cancer. Throughout these Condensed Consolidated Financial Statements, Curis, Inc. and its wholly owned subsidiaries are collectively referred to as “the Company,” “Curis,” “we,” “us,” or “our.” The Company conducts its research and development programs both internally and through strategic collaborations. The Company has prioritized its lead clinical stage drug candidate emavusertib, an orally available small molecule inhibitor of Interleukin-1 receptor associated kinase 4 (“IRAK4”). 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”). The Company is party to 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. 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 Company’s ability to execute on its overall business strategies; 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; 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 entities managed by Oberland Capital Management, LLC (the “Purchasers”), and Lind SA LLC (the “Agent”), as collateral agent for the Purchasers; and the Company’s ability to maintain its current listing on Nasdaq. 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 losses and negative cash flows from operations since its inception. As of March 31, 2023, the Company had an accumulated deficit of $1.2 billion, and for the three months ended March 31, 2023, the Company incurred a net loss of $11.6 million and used $12.2 million of cash in operations. The Company expects to continue to generate operating losses in the foreseeable future. The Company anticipates that its $71.8 million of existing cash, cash equivalents and investments at March 31, 2023 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	3 Months Ended
	Mar. 31, 2023
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, 2022 as filed with the Securities and Exchange Commission (“SEC”) on March 13, 2023. In the opinion of the management of the Company, the unaudited Condensed Consolidated 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 March 31, 2023; the results of operations for the three-month period ended March 31, 2023 and 2022; stockholders' equity for the three-month period ended March 31, 2023 and 2022; and the cash flows for the three-month period ended March 31, 2023 and 2022. The Condensed Consolidated Balance Sheet at December 31, 2022 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 revenue, expenses and certain assets and liabilities at the balance sheet date. Such estimates include the performance obligations under the Company’s collaboration agreements; the collectability of receivables; the carrying value of goodwill; 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. (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 investments are marketable securities. The Company classified $0.6 million of its cash as restricted cash as of March 31, 2023 and December 31, 2022. These amounts represent the security deposit associated with the Company’s Lexington, Massachusetts headquarters. 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. 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. 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. (d) Leases The Company determines if an arrangement is a lease at contract inception. The Company made an accounting policy election to not recognize leases with an initial term of 12 months or less within its Consolidated Balance Sheets and to recognize those lease payments on a straight-line basis in its Consolidated Statements of Operations and Comprehensive Loss over the lease term. 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. 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) Other Assets Other assets consist of long-term prepayments and deposits. (f) Revenue Recognition The Company applies the revenue recognition guidance in accordance with Financial Accounting Standards Board (“FASB”) Codification Topic 606, Revenue from Contracts with Customers. Revenue is recognized when persuasive evidence of an arrangement exists, delivery has occurred and title has passed, the price is fixed or determinable, and collectability is reasonably assured. 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 8, Research and Development Collaborations ). However, a substantial portion of potential Erivedge royalties will be paid to the Purchasers pursuant to the Oberland Purchase Agreement (see Note 7, Liability Related to the Sale of Future Royalties ). (g) Segment Reporting The Company has determined that it operates in a single reportable segment, which is the research and development of innovative drug candidates for the treatment of human cancer. (h) New Accounting Pronouncements The Company assesses the applicability and impact of any recent Accounting Standards Updates (“ASUs”) issued by the FASB. Based on this assessment, recently issued ASUs were either not applicable or expected to have an immaterial impact on the Company’s Condensed Consolidated Financial Statements.

Fair Value of Financial Instrum

Fair Value of Financial Instruments	3 Months Ended
	Mar. 31, 2023
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	Fair Value of Financial Instruments The Company applies the provisions of Accounting Standards Codification 820, Fair Value Measurements (“ASC 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 considers assumptions that market participants would use when pricing the asset or liability. ASC 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 March 31, 2023 and December 31, 2022 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. (in thousands) Quoted Prices in Other Observable Unobservable Fair Value As of March 31, 2023: Cash equivalents: Money market funds $ 27,864 $ — $ — $ 27,864 U.S. treasury securities and government agency obligations — 1,998 — 1,998 Short-term investments: Corporate debt securities and commercial paper — 28,726 — 28,726 U.S. treasury securities and government agency obligations — 11,337 — 11,337 Total $ 27,864 $ 42,061 $ — $ 69,925 (in thousands) Quoted Prices in Other Observable Unobservable Fair Value As of December 31, 2022: Cash equivalents: Money market funds $ 15,215 $ — $ — $ 15,215 U.S. treasury securities and government agency obligations — 2,998 — 2,998 Short-term investments: Corporate debt securities and commercial paper — 42,071 — 42,071 U.S. treasury securities and government agency obligations — 23,894 — 23,894 Total $ 15,215 $ 68,963 $ — $ 84,178

Investments

Investments	3 Months Ended
	Mar. 31, 2023
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 March 31, 2023 are as follows: (in thousands) Amortized Unrealized Unrealized Fair Value Short-term investments: Corporate debt securities and commercial paper $ 28,729 $ — $ (3) $ 28,726 U.S. treasury securities and government agency obligations 11,325 13 (1) 11,337 Total investments $ 40,054 $ 13 $ (4) $ 40,063 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, 2022 are as follows: (in thousands) Amortized Unrealized Unrealized Fair Value Short-term investments: Corporate debt securities and commercial paper $ 42,109 $ 2 $ (40) $ 42,071 U.S. treasury securities and government agency obligations 24,042 — (148) 23,894 Total investments $ 66,151 $ 2 $ (188) $ 65,965 The weighted average maturity of short-term investments was 0.3 years at December 31, 2022. No credit losses on available-for-sale securities were recognized during the three months ended March 31, 2023 or 2022. 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. As of March 31, 2023, the Company held no investments that have been in a continuous unrealized loss position for 12 months or longer. The aggregate fair value of available-for-sale investments in a continuous unrealized loss position for 12 months or longer was $27.4 million as of December 31, 2022.

Accrued Liabilities

Accrued Liabilities	3 Months Ended
	Mar. 31, 2023
Other Liabilities Disclosure [Abstract]
Accrued Liabilities	Accrued Liabilities Accrued liabilities consisted of the following: (in thousands) March 31, 2023 December 31, 2022 Headcount related costs $ 1,494 $ 3,152 Research and development costs 1,564 762 Professional and legal fees 1,110 1,727 Other 78 38 Total $ 4,246 $ 5,679

Lease

Lease	3 Months Ended
	Mar. 31, 2023
Leases [Abstract]
Lease	Lease The Company has a single lease for real estate, including laboratory and office space, and certain equipment, in Lexington, Massachusetts which commenced on May 1, 2020. A portion of the Company’s leased space is subject to an early termination option that 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. The Company expects the lease to end as of December 31, 2025. As of March 31, 2023, the Company had an operating lease liability of $3.7 million and related right-of-use asset of $4.1 million related to its operating lease. As of December 31, 2022, the Company had an operating lease liability of $3.9 million and related right-of-use asset of $4.4 million related to its operating lease. The Company recorded lease cost of $0.4 million and $0.3 million for the three months ended March 31, 2023 and 2022, respectively.

Liability Related to the Sale o

Liability Related to the Sale of Future Royalties	3 Months Ended
	Mar. 31, 2023
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 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 sold to the Purchasers a portion of its rights to receive royalties from Genentech on potential net sales of Erivedge. 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 (referred to as the “Purchased Receivables”), at a price (referred to as the “Put/Call Price”), equal to 250% 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 evaluates the fair value of the put option each reporting period. The estimated fair value of the put option is immaterial as of March 31, 2023 and December 31, 2022, respectively. 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 as of March 31, 2023. As a result of the obligation to pay future royalties to the Purchasers, the Company recorded the proceeds as a liability on its Condensed Consolidated Balance Sheets. It accounts for the liability and interest expense using the interest method over the expected 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 Oberland Purchase Agreement is based on the amount of royalty payments expected to be received by the Purchasers over the life of the Oberland Purchase Agreement. The projected amount of royalty payments expected to be paid to the Purchasers 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 prospectively 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 6.2%. The Company incurred $0.6 million of transaction costs in connection with the Oberland Purchase Agreement. These transaction costs will be amortized to imputed interest expense over the estimated term of the Oberland Purchase Agreement. The carrying value of the liability related to the sale of future royalties approximates fair value as of March 31, 2023 and is based on our current estimates of future royalties expected to be paid the Purchasers over the life of the arrangement, which are considered Level 3 inputs. The following table shows the activity with respect to the liability related to the sale of future royalties during the three months ended March 31, 2023. (in thousands) Carrying value of liability related to the sale of future royalties at January 1, 2023 $ 49,483 Other 15 Imputed interest expense 569 Less: payments to the Purchasers (2,674) Carrying value of liability related to the sale of future royalties at March 31, 2023 $ 47,393 In March 2023, Curis and Curis Royalty received a letter from counsel to Oberland Capital Management, LLC, the Purchasers and the Agent alleging defaults under Sections 4.04 and 6.04(b) of the Oberland Purchase Agreement and demanding cure of the asserted default under Section 6.04(b) of the Oberland Purchase Agreement. The asserted basis for the alleged defaults is that Curis and Curis Royalty were required to disclose, and failed to disclose, certain information prior to execution of the Oberland Purchase Agreement and that Curis and Curis Royalty have since failed to disclose certain information that has been requested by the Purchasers pursuant to Section 6.04(b) of the Oberland Purchase Agreement. The letter further alleges that these alleged defaults are events of default under the Oberland Purchase Agreement and that each alleged default separately entitles the Purchasers to exercise the put option described above, which would require Curis Royalty to repurchase the Purchased Receivables at the Put/Call Price. The Purchasers have not attempted to exercise that put option but have purported to reserve their alleged right to exercise it without further notice. As of March 31, 2023, the estimated amount of the Put/Call Price is up to $72.5 million. The Purchasers have also reserved other asserted rights in respect of the alleged defaults, including the asserted right to seek judicial remedies, including for damages and rescission, and to assert alleged claims against Curis and Curis Royalty for indemnification on the basis of material breach and fraud in the inducement. Curis and Curis Royalty dispute these allegations. However, if Oberland elects to pursue these claims, and if Curis and Curis Royalty are unsuccessful in defending against these claims, it could have a material adverse impact on Curis and Curis Royalty, including their ability to continue as a going concern.

Research and Development Collab

Research and Development Collaborations	3 Months Ended
	Mar. 31, 2023
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, outside of the U.S. for the treatment of advanced BCC. The Company has received $59.0 million in cash milestone payments as of March 31, 2023. 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 $2.3 million and $2.1 million in royalty revenue under the Genentech collaboration during the three months ended March 31, 2023 and 2022, respectively. Cost of royalties comprises payments to university licensors and was immaterial for the three months ended March 31, 2023 and 2022. The Company has accounts receivables from Genentech under this collaboration of $2.3 million and $3.0 million as of March 31, 2023 and December 31, 2022, respectively, in its Condensed Consolidated Balance Sheets. As previously discussed in Note 7, Liability Related to the Sale of Future Royalties, a significant 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 The Company is party to 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. 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. Additionally, Aurigene retains the rights to develop and commercialize CA-170 in Asia, and the Company is 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 March 31, 2023, 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). 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. 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. 4. 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, 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. In addition to the collaboration agreement, the Company is party to a master development and manufacturing agreement with Aurigene for the supply of drug substance and drug product. Under this agreement, the Company incurred $0.2 million in research and development expense during the three months ended March 31, 2023. (c) ImmuNext The Company is party to 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. 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	3 Months Ended
	Mar. 31, 2023
Equity [Abstract]
Common Stock	Common Stock 2021 Sales Agreement with Cantor Fitzgerald & Co. and JonesTrading Institutional Services LLC The Company is party to a sales agreement (the “2021 Sales Agreement”) with Cantor Fitzgerald & Co. (“Cantor”) and JonesTrading Institutional Services LLC (“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. The Company did not sell any shares of common stock under the 2021 Sales Agreement during the three months ended March 31, 2023 or 2022. As of March 31, 2023, $93.7 million remained available for sale under the 2021 Sales Agreement.

Stock Plans and Stock-Based Com

Stock Plans and Stock-Based Compensation	3 Months Ended
	Mar. 31, 2023
Share-Based Payment Arrangement [Abstract]
Stock Plans and Stock-Based Compensation	Stock Plans and Stock-Based Compensation As of March 31, 2023, the Company had two stockholder-approved, stock-based compensation plans: (i) the Fourth Amended and Restated 2010 Stock Incentive Plan (“2010 Plan”) and (ii) the Amended and Restated 2010 Employee Stock Purchase Plan, (“ESPP”). New employees are typically issued options as an inducement equity award under Nasdaq Listing Rule 5635(c)(4) outside of the 2010 Plan (“Inducement Awards”). 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. The Company can issue up to 23,190,000 shares of its common stock pursuant to awards granted under the 2010 Plan. Options vest and become exercisable based on a schedule 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 March 31, 2023, 7,455,780 shares remained available for grant under the 2010 Plan. Stock Options During the three months ended March 31, 2023, the Company’s board of directors granted options to purchase 4,403,600 shares of the Company’s common stock to the officers and employees of the Company under the 2010 Plan. These options vest and become exercisable as to 25% of the shares underlying the award after the first year and as to an additional 6.25% of the shares underlying the award in each subsequent quarter, based upon continued employment over a four year period, and are exercisable at a price equal to the closing market price of the Company’s common stock on the grant date. During the three months ended March 31, 2023, 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 in one year from the date of grant. These options were granted at an exercise price that equaled the closing market price of the Company’s common stock on the grant date. Inducement Awards For certain new employees, the Company issues Inducement Awards. These options 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 quarter thereafter. During the three months ended March 31, 2023, the Company’s board of directors granted Inducement Awards to purchase 135,450 shares of common stock. These options are granted at an exercise price that equals the closing market price of the Company’s common stock on the grant date. 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, 2022 13,673,256 $ 3.24 6.51 Granted 4,964,050 0.70 Exercised (10,312) 0.67 Canceled/Forfeited (1,125,903) 3.91 Outstanding, March 31, 2023 17,501,091 $ 2.48 7.68 $ — Exercisable at March 31, 2023 8,404,265 $ 3.19 5.96 $ — Vested and unvested expected to vest at March 31, 2023 17,501,091 $ 2.48 7.68 $ — The weighted average grant date fair values of the stock options granted during the three months ended March 31, 2023 and 2022 were $0.59 and $2.62, respectively, and were calculated using the following estimated assumptions under the Black-Scholes option pricing model: Three Months Ended 2023 2022 Expected term (years) 5.5 5.5 Risk free interest rate 3.6% 1.4-1.7% Expected volatility 115% - 116% 110% - 111% Expected dividends None None As of March 31, 2023, there was approximately $12.4 million of unrecognized compensation cost related to unvested employee stock option awards outstanding, which is expected to be recognized as expense over a weighted average period of 3.00 years. The intrinsic value of employee stock options exercised during the three months ended March 31, 2023 was immaterial. There were no employee stock options exercised during the three months ended March 31, 2022. 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. During the three months ended March 31, 2023 and 2022, no shares were issued under the ESPP. As of March 31, 2023, there were 1,175,008 shares available for future purchase under the ESPP. Stock-Based Compensation Expense For the three months ended March 31, 2023 and 2022, 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: Three Months Ended (in thousands) 2023 2022 Research and development expenses $ 629 $ 725 General and administrative expenses 766 993 Total stock-based compensation expense $ 1,395 $ 1,718

Loss Per Common Share

Loss Per Common Share	3 Months Ended
	Mar. 31, 2023
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 months ended March 31, 2023 and 2022, 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 17,501,091 and 14,343,706 as of March 31, 2023 and 2022, respectively.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2023
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, 2022 as filed with the Securities and Exchange Commission (“SEC”) on March 13, 2023.
Use of Estimates and Assumptions	Use of Estimates and AssumptionsThe 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 revenue, expenses and certain assets and liabilities at the balance sheet date. Such estimates include the performance obligations under the Company’s collaboration agreements; the collectability of receivables; the carrying value of goodwill; 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.
Cash Equivalents, Restricted Cash, and Investments	Cash Equivalents, Restricted Cash, and Investments Cash equivalents consist of highly liquid investments purchased with original maturities of three months or less. All other investments are marketable securities. The Company classified $0.6 million of its cash as restricted cash as of March 31, 2023 and December 31, 2022. These amounts represent the security deposit associated with the Company’s Lexington, Massachusetts headquarters. 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. 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. 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.
Leases	Leases The Company determines if an arrangement is a lease at contract inception. The Company made an accounting policy election to not recognize leases with an initial term of 12 months or less within its Consolidated Balance Sheets and to recognize those lease payments on a straight-line basis in its Consolidated Statements of Operations and Comprehensive Loss over the lease term. 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. 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.
Other Assets	Other AssetsOther assets consist of long-term prepayments and deposits.
Revenue Recognition	Revenue Recognition The Company applies the revenue recognition guidance in accordance with Financial Accounting Standards Board (“FASB”) Codification Topic 606, Revenue from Contracts with Customers. Revenue is recognized when persuasive evidence of an arrangement exists, delivery has occurred and title has passed, the price is fixed or determinable, and collectability is reasonably assured. 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 8, Research and Development Collaborations ). However, a substantial portion of potential Erivedge royalties will be paid to the Purchasers pursuant to the Oberland Purchase Agreement (see Note 7, Liability Related to the Sale of Future Royalties ).
Segment Reporting	Segment ReportingThe Company has determined that it operates in a single reportable segment, which is the research and development of innovative drug candidates for the treatment of human cancer.
New Accounting Pronouncements	New Accounting PronouncementsThe Company assesses the applicability and impact of any recent Accounting Standards Updates (“ASUs”) issued by the FASB. Based on this assessment, recently issued ASUs were either not applicable or expected to have an immaterial impact on the Company’s Condensed Consolidated Financial Statements.
Fair Value of Financial Instruments	Fair Value of Financial Instruments The Company applies the provisions of Accounting Standards Codification 820, Fair Value Measurements (“ASC 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 considers assumptions that market participants would use when pricing the asset or liability. ASC 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)	3 Months Ended
	Mar. 31, 2023
Fair Value Disclosures [Abstract]
Schedule of Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis	In accordance with the fair value hierarchy, the following table shows the fair value as of March 31, 2023 and December 31, 2022 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. (in thousands) Quoted Prices in Other Observable Unobservable Fair Value As of March 31, 2023: Cash equivalents: Money market funds $ 27,864 $ — $ — $ 27,864 U.S. treasury securities and government agency obligations — 1,998 — 1,998 Short-term investments: Corporate debt securities and commercial paper — 28,726 — 28,726 U.S. treasury securities and government agency obligations — 11,337 — 11,337 Total $ 27,864 $ 42,061 $ — $ 69,925 (in thousands) Quoted Prices in Other Observable Unobservable Fair Value As of December 31, 2022: Cash equivalents: Money market funds $ 15,215 $ — $ — $ 15,215 U.S. treasury securities and government agency obligations — 2,998 — 2,998 Short-term investments: Corporate debt securities and commercial paper — 42,071 — 42,071 U.S. treasury securities and government agency obligations — 23,894 — 23,894 Total $ 15,215 $ 68,963 $ — $ 84,178

Investments (Tables)

Investments (Tables)	3 Months Ended
	Mar. 31, 2023
Investments, Debt and Equity Securities [Abstract]
Schedule of Amortized Cost, Unrealized Gains and Losses and Fair Value of Investments Available-for-Sale	The amortized cost, including interest receivable, unrealized gains and losses and fair value of investments available-for-sale as of March 31, 2023 are as follows: (in thousands) Amortized Unrealized Unrealized Fair Value Short-term investments: Corporate debt securities and commercial paper $ 28,729 $ — $ (3) $ 28,726 U.S. treasury securities and government agency obligations 11,325 13 (1) 11,337 Total investments $ 40,054 $ 13 $ (4) $ 40,063 The amortized cost, including interest receivable, unrealized gains and losses and fair value of investments available-for-sale as of December 31, 2022 are as follows: (in thousands) Amortized Unrealized Unrealized Fair Value Short-term investments: Corporate debt securities and commercial paper $ 42,109 $ 2 $ (40) $ 42,071 U.S. treasury securities and government agency obligations 24,042 — (148) 23,894 Total investments $ 66,151 $ 2 $ (188) $ 65,965

Accrued Liabilities (Tables)

Accrued Liabilities (Tables)	3 Months Ended
	Mar. 31, 2023
Other Liabilities Disclosure [Abstract]
Schedule of Accrued Liabilities	Accrued liabilities consisted of the following: (in thousands) March 31, 2023 December 31, 2022 Headcount related costs $ 1,494 $ 3,152 Research and development costs 1,564 762 Professional and legal fees 1,110 1,727 Other 78 38 Total $ 4,246 $ 5,679

Liability Related to the Sale_2

Liability Related to the Sale of Future Royalties (Tables)	3 Months Ended
	Mar. 31, 2023
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 three months ended March 31, 2023. (in thousands) Carrying value of liability related to the sale of future royalties at January 1, 2023 $ 49,483 Other 15 Imputed interest expense 569 Less: payments to the Purchasers (2,674) Carrying value of liability related to the sale of future royalties at March 31, 2023 $ 47,393

Stock Plans and Stock-Based C_2

Stock Plans and Stock-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2023
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, 2022 13,673,256 $ 3.24 6.51 Granted 4,964,050 0.70 Exercised (10,312) 0.67 Canceled/Forfeited (1,125,903) 3.91 Outstanding, March 31, 2023 17,501,091 $ 2.48 7.68 $ — Exercisable at March 31, 2023 8,404,265 $ 3.19 5.96 $ — Vested and unvested expected to vest at March 31, 2023 17,501,091 $ 2.48 7.68 $ — The weighted average grant date fair values of the stock options granted during the three months ended March 31, 2023 and 2022 were $0.59 and $2.62, respectively, and were calculated using the following estimated assumptions under the Black-Scholes option pricing model: Three Months Ended 2023 2022 Expected term (years) 5.5 5.5 Risk free interest rate 3.6% 1.4-1.7% Expected volatility 115% - 116% 110% - 111% Expected dividends None None
Schedule of Share Based Compensation Allocation of Recognized Period Costs	For the three months ended March 31, 2023 and 2022, 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: Three Months Ended (in thousands) 2023 2022 Research and development expenses $ 629 $ 725 General and administrative expenses 766 993 Total stock-based compensation expense $ 1,395 $ 1,718

Nature of Business (Details)

Nature of Business (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Accumulated deficit	$ 1,160,556		$ 1,148,997
Net loss	11,559	$ 16,109
Cash used in operations	12,199	$ 16,815
Cash, cash equivalents, and investments	$ 71,800

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Details) $ in Millions	3 Months Ended
	Mar. 31, 2023 USD ($) segment	Dec. 31, 2022 USD ($)
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Restricted cash | $	$ 0.6	$ 0.6
Number of reportable segments | segment	1

Fair Value of Financial Instr_3

Fair Value of Financial Instruments - (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Short-term investments:
Total	$ 69,925	$ 84,178
Corporate debt securities and commercial paper
Short-term investments:
Short-term investments:	28,726	42,071
U.S. treasury securities and government agency obligations
Short-term investments:
Short-term investments:	11,337	23,894
Money market funds
Cash equivalents:
Money market funds	27,864	15,215
U.S. treasury securities and government agency obligations
Cash equivalents:
Money market funds	1,998	2,998
Quoted Prices in Active Markets (Level 1)
Short-term investments:
Total	27,864	15,215
Quoted Prices in Active Markets (Level 1) | Corporate debt securities and commercial paper
Short-term investments:
Short-term investments:	0	0
Quoted Prices in Active Markets (Level 1) | U.S. treasury securities and government agency obligations
Short-term investments:
Short-term investments:	0	0
Quoted Prices in Active Markets (Level 1) | Money market funds
Cash equivalents:
Money market funds	27,864	15,215
Quoted Prices in Active Markets (Level 1) | U.S. treasury securities and government agency obligations
Cash equivalents:
Money market funds	0	0
Other Observable Inputs (Level 2)
Short-term investments:
Total	42,061	68,963
Other Observable Inputs (Level 2) | Corporate debt securities and commercial paper
Short-term investments:
Short-term investments:	28,726	42,071
Other Observable Inputs (Level 2) | U.S. treasury securities and government agency obligations
Short-term investments:
Short-term investments:	11,337	23,894
Other Observable Inputs (Level 2) | Money market funds
Cash equivalents:
Money market funds	0	0
Other Observable Inputs (Level 2) | U.S. treasury securities and government agency obligations
Cash equivalents:
Money market funds	1,998	2,998
Unobservable Inputs (Level 3)
Short-term investments:
Total	0	0
Unobservable Inputs (Level 3) | Corporate debt securities and commercial paper
Short-term investments:
Short-term investments:	0	0
Unobservable Inputs (Level 3) | U.S. treasury securities and government agency obligations
Short-term investments:
Short-term investments:	0	0
Unobservable Inputs (Level 3) | Money market funds
Cash equivalents:
Money market funds	0	0
Unobservable Inputs (Level 3) | U.S. treasury securities and government agency obligations
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 ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2023	Dec. 31, 2022	Mar. 31, 2022
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 40,054,000	$ 66,151,000
Unrealized Gain	13,000	2,000
Unrealized Loss	(4,000)	(188,000)
Fair Value	$ 40,063,000	65,965,000
Weighted-average maturity of short-term investments	3 months 18 days
Debt securities, available-for-sale, credit loss	$ 0		$ 0
Fair value of available-for-sale investments in a continuous unrealized loss position for 12 months or longer		$ 27,400,000
Short-term investments:
Debt Securities, Available-for-sale [Line Items]
Weighted-average maturity of short-term investments		3 months 18 days
Short-term investments: | Minimum
Debt Securities, Available-for-sale [Line Items]
Range of maturities	1 month
Short-term investments: | Maximum
Debt Securities, Available-for-sale [Line Items]
Range of maturities	12 months
Corporate debt securities and commercial paper
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 28,729,000	$ 42,109,000
Unrealized Gain	0	2,000
Unrealized Loss	(3,000)	(40,000)
Fair Value	28,726,000	42,071,000
U.S. treasury securities and government agency obligations
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	11,325,000	24,042,000
Unrealized Gain	13,000	0
Unrealized Loss	(1,000)	(148,000)
Fair Value	$ 11,337,000	$ 23,894,000

Accrued Liabilities - (Details)

Accrued Liabilities - (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Other Liabilities Disclosure [Abstract]
Headcount related costs	$ 1,494	$ 3,152
Research and development costs	1,564	762
Professional and legal fees	1,110	1,727
Other	78	38
Total	$ 4,246	$ 5,679

Lease (Details)

Lease (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Lessee, Lease, Description [Line Items]
Operating lease, liability	$ 3,700		$ 3,900
Operating lease right-of-use asset	4,076		$ 4,401
Operating lease, expense	$ 400	$ 300
Remaining lease term	6 years
Lease obligations	$ 8,800
Operating lease payments	$ 400	$ 300
Weighted average discount rate	9.95%
128 Spring Street Lease Amendment
Lessee, Lease, Description [Line Items]
Lessor option to terminate, written notice period	18 months

Liability Related to the Sale_3

Liability Related to the Sale of Future Royalties - Narrative (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2023
Nonmonetary Transaction [Line Items]
Non-cash interest rate	6.20%
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
Percentage of royalty purchase agreement		250%
Estimated price amount		$ 72.5
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	3 Months Ended
	Mar. 31, 2023 USD ($)
Nonmonetary Transaction [Roll Forward]
Carrying value of liability related to the sale of future royalties at January 1, 2023	$ 49,483
Other	15
Imputed interest expense	569
Less: payments to the Purchasers	(2,674)
Carrying value of liability related to the sale of future royalties at March 31, 2023	$ 47,393

Research and Development Coll_2

Research and Development Collaborations (Details) $ in Thousands	1 Months Ended	3 Months Ended
	Jun. 30, 2003	Mar. 31, 2023 USD ($) program	Mar. 31, 2022 USD ($)	Dec. 31, 2022 USD ($)	Feb. 29, 2020
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenues, net		$ 2,297	$ 2,057
Accounts receivable		$ 2,314		$ 2,975
Number of program licensed | program		4
Genentech, Inc.
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Amount received for specified clinical development and regulatory objectives		$ 59,000
Percentage of royalty rate decrease	2%
Accounts receivable		2,300		$ 3,000
Genentech, Inc. | Royalties
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenues, net		2,300	$ 2,100
Genentech, Inc. | Maximum
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
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
Aurigene | Master Development and Manufacturing Agreement | Research and Development Expense
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Collaborative arrangement payments agreement		200
Aurigene | Maximum
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Royalty fees receivable (as a percent)					10%
ImmuNext | Maximum
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Option exercise fee		20,000
Development milestone payments		4,600
Regulatory approval milestone payments		84,300
Sales milestone payments		$ 125,000

Common Stock (Details)

Common Stock (Details) - Common Stock - Cantor Fitzgerald & Co - USD ($)	Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2021
Class of Stock [Line Items]
Common stock authorized			$ 100,000,000
Compensation fee		3%
Sale of stock remaining authorized amount	$ 93,700,000

Stock Plans and Stock-Based C_3

Stock Plans and Stock-Based Compensation - Narrative (Details)	1 Months Ended	3 Months Ended
	May 31, 2021 shares	Mar. 31, 2023 USD ($) plan purchase_period $ / shares shares	Mar. 31, 2022 $ / shares shares
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Number of shareholder-approved, share-based compensation plans | plan		2
Granted (in shares)		4,964,050
Weighted average grant-date fair values of stock options (in dollars per share) | $ / shares		$ 0.59	$ 2.62
Unrecognized compensation cost, net of estimated forfeitures | $		$ 12,400,000
Unrecognized compensation cost, weighted average period for recognition		3 years
Intrinsic values of employee stock options exercised | $		$ 0
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		7,455,780
2010 Plan
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Granted (in shares)		4,403,600
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)		0	0
Employee Stock | Employee Stock Purchase Plan
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Shares authorized (in shares)		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
Term of purchase periods		6 months
Shares available for future purchase under ESPP (in shares)		1,175,008
Stock Options, or Stock Appreciation Rights | Amended and Restated 2010 Stock Incentive Plan
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
Restricted Stock, RSUs, Other Stock-Based Awards, or Performance Awards | Amended and Restated 2010 Stock Incentive Plan
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%
Restricted Stock
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Vesting period (years)		4 years
Restricted Stock | Officer
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Awarded (in shares)		135,450

Stock Plans and Stock-Based C_4

Stock Plans and Stock-Based Compensation - Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2023	Dec. 31, 2022
Number of Shares
Beginning balance (in shares)	13,673,256
Granted (in shares)	4,964,050
Exercised (in shares)	(10,312)
Canceled/Forfeited (in shares)	(1,125,903)
Ending balance (in shares)	17,501,091	13,673,256
Exercisable at end of period (in shares)	8,404,265
Vested and unvested expected to vest at end of period (in shares)	17,501,091
Weighted Average Exercise Price per Share
Beginning balance (in dollars per share)	$ 3.24
Granted (in dollars per share)	0.70
Exercised (in dollars per share)	0.67
Canceled/Forfeited (in dollars per share)	3.91
Ending balance (in dollars per share)	2.48	$ 3.24
Exercisable at end of period (in dollars per share)	3.19
Vested and unvested expected to vest at end of period (in dollars per share)	$ 2.48
Weighted Average Remaining Contractual Life
Outstanding at end of period	7 years 8 months 4 days	6 years 6 months 3 days
Exercisable at end of period	5 years 11 months 15 days
Vested and unvested expected to vest at end of period	7 years 8 months 4 days
Aggregate Intrinsic Value
Outstanding at end of period	$ 0
Exercisable at end of period	0
Vested and unvested expected to vest at end of period	$ 0

Stock Plans and Stock-Based C_5

Stock Plans and Stock-Based Compensation - Key Assumptions (Details)	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Share-Based Payment Arrangement [Abstract]
Expected term	5 years 6 months	5 years 6 months
Risk -free Interest rate (minimum)		1.40%
Risk -free Interest rate (maximum)	3.60%	1.70%
Expected volatility (minimum)	115%	110%
Expected volatility (maximum)	116%	111%

Stock Plans and Stock-Based C_6

Stock Plans and Stock-Based Compensation - Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Total stock-based compensation expense	$ 1,395,000	$ 1,718
Research and development expenses
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Total stock-based compensation expense	629,000	725
General and administrative expenses
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Total stock-based compensation expense	$ 766,000	$ 993

Loss Per Common Share (Details)

Loss Per Common Share (Details) - shares	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Stock Options Outstanding
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities (in shares)	17,501,091	14,343,706