Curis (CRIS) 10-Q 4 May 17 2017 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2017	Apr. 26, 2017
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q1
Trading Symbol	CRIS
Entity Registrant Name	CURIS INC
Entity Central Index Key	1,108,205
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		143,772,716

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Current Assets:
Cash and cash equivalents	$ 42,417	$ 26,038
Investments	18,385	18,447
Short-term investment – restricted	153	0
Accounts receivable	2,195	2,459
Prepaid expenses and other current assets	1,218	1,257
Total current assets	64,368	48,201
Property and equipment, net	410	413
Long-term investment – restricted	0	153
Goodwill	8,982	8,982
Other assets	3	3
Total assets	73,763	57,752
Current Liabilities:
Accounts payable	5,905	5,883
Accrued liabilities	1,573	2,725
Current portion of long-term debt, net	3,502	4,939
Total current liabilities	10,980	13,547
Long-term debt, net	41,306	14,921
Other long-term liabilities	0	18
Total liabilities	52,286	28,486
Commitments
Stockholders’ Equity:
Common stock, $0.01 par value—225,000,000 shares authorized; 144,900,004 shares issued and 143,677,158 shares outstanding at March 31, 2017; 142,346,871 shares issued and 141,124,025 shares outstanding at December 31, 2016	1,449	1,423
Additional paid-in capital	936,248	928,319
Treasury stock (at cost, 1,222,846 shares)	(1,524)	(1,524)
Accumulated deficit	(914,690)	(898,948)
Accumulated other comprehensive income	(6)	(4)
Total stockholders’ equity	21,477	29,266
Total liabilities and stockholders’ equity	$ 73,763	$ 57,752

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - $ / shares	Mar. 31, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	225,000,000	225,000,000
Common stock, shares issued	144,900,004	142,346,871
Common stock, shares outstanding	143,677,158	141,124,025
Treasury stock, at cost (in shares)	1,222,846	1,222,846

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Revenues:
Royalties	$ 2,191	$ 1,744
Research and development, net	(60)	(18)
Total revenues	2,131	1,726
Costs and expenses:
Cost of royalty revenues	111	89
Research and development	13,541	6,828
General and administrative	3,532	3,616
Total costs and expenses	17,184	10,533
Loss from operations	(15,053)	(8,807)
Other (expense) income:
Other (expense) income:	(103)	0
Interest income	70	105
Interest expense	(656)	(740)
Total other expense, net	(689)	(635)
Net loss	$ (15,742)	$ (9,442)
Net loss per common share (basic and diluted) (in dollars per share)	$ (0.11)	$ (0.07)
Weighted average common shares (basic and diluted) (in shares)	142,011,776	129,019,984
Total comprehensive loss	$ (15,744)	$ (9,410)

Condensed Consolidated Stateme5

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Cash flows from operating activities:
Net loss	$ (15,742)	$ (9,442)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	55	34
Stock-based compensation expense	1,103	772
Amortization of debt issuance costs	119	12
Non-cash interest expense on investments	(10)	(16)
Changes in operating assets and liabilities:
Accounts receivable	264	360
Prepaid expenses and other assets	213	243
Accounts payable and accrued and other liabilities	(1,148)	50
Total adjustments	596	1,455
Net cash used in operating activities	(15,146)	(7,987)
Cash flows from investing activities:
Purchase of investments	(12,556)	(29,467)
Sale of investments	12,626	20,184
Purchases of property and equipment	(52)	(8)
Net cash provided by/(used in) investing activities	18	(9,291)
Cash flows from financing activities:
Proceeds from issuance of common stock associated with offerings, net of issuance costs	6,214	0
Proceeds from issuance of common stock under the Company’s share-based compensation plans	464	70
Proceeds from credit agreement with HealthCare Royalty Partners, III, L.P.	45,000	0
Payment of debt issuance costs	(192)	0
Payment on termination of credit agreement with BioPharma-II	(18,303)	0
Payments on Curis Royalty’s debt	(1,676)	(1,191)
Net cash (used in)/provided by financing activities	31,507	(1,121)
Net (decrease)/increase in cash and cash equivalents	16,379	(18,399)
Cash and cash equivalents, beginning of period	26,038	33,091
Cash and cash equivalents, end of period	42,417	14,692
Non-cash items:
Receivable for issuances of common stock	$ 174	$ 0

Nature of Business

Nature of Business	3 Months Ended
	Mar. 31, 2017
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 for the treatment of human cancers. As used throughout these consolidated financial statements, the term “the Company” refers to the business of Curis, Inc. and its wholly owned subsidiaries, except where the context otherwise requires, and the term “Curis” refers to Curis, Inc. The Company conducts its research and development programs both internally and through strategic collaborations. The Company’s clinical stage drug candidates are CUDC-907, which is being investigated in clinical studies in patients with diffuse large B-cell lymphoma and solid tumors and CA-170, which is being investigated in a Phase 1 study in patients with advanced solid tumors and lymphomas. The Company’s pipeline includes two pre-Investigational New Drug, or IND, stage oncology drug candidates, CA-327 and CA-4948. The Company’s drug Erivedge® (vismodegib) is approved for the treatment of advanced basal cell carcinoma, or BCC. The Company is party to a collaboration with F. Hoffmann-La Roche Ltd, or Roche, and Genentech Inc., or Genentech, a member of the Roche Group, under which Roche and Genentech are commercializing Erivedge, a first-in-class orally-administered small molecule Hedgehog signaling pathway inhibitor. In addition to BCC, Roche and Genentech are conducting studies of Erivedge in other diseases, including in idiopathic pulmonary fibrosis and myelofibrosis. In January 2015, and as amended in September 2016, the Company entered into an exclusive collaboration, option and license agreement focused on immuno-oncology and selected precision oncology targets with Aurigene Discovery Technologies Limited, or Aurigene. The collaboration with Aurigene is comprised of multiple programs, and Curis has the option to exclusively license each program, including data, intellectual property and compounds associated therewith, once a development candidate is nominated within such program. In October 2015, the Company exercised options to license the first two programs under this collaboration. The first licensed program is in the immuno-oncology field and the Company has named CA-170, an orally-available small molecule antagonist of two immune checkpoints, programmed death ligand-1 (PDL1) and V domain Ig suppressor of T cell activation (VISTA), as the development candidate from this program. CA-170 is currently in Phase 1 clinical testing. The second licensed program is in the precision oncology field and the Company has named CA-4948, an orally-available small molecule inhibitor of Interleukin-1 receptor-associated kinase 4 (IRAK4), as the development candidate. In October 2016, the Company exercised its option to license a third program in the collaboration, and designated CA-327, a distinct orally available small molecule antagonist of two immune checkpoints, PDL1 and T-cell immunoglobulin and mucin domain containing protein-3 (TIM3), as the development candidate from this program. The Company expects to file IND applications with the United States Food and Drug Administration, or FDA, for clinical testing of CA-4948 and CA-327 in the second half of 2017. The Company operates in a single reportable segment, which is the research and development of innovative cancer therapeutics. The Company expects that any products that are successfully developed and commercialized would be used in the health care industry and would be regulated in the United States by the FDA and in overseas markets by similar regulatory authorities. 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 advance and expand its research and development programs; the Company’s reliance on Aurigene to successfully discover and preclinically develop drug candidates under the parties’ collaboration agreement; 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 Company’s ability to obtain adequate financing to fund its operations; the ability of the Company and its wholly owned subsidiary, Curis Royalty, LLC, or Curis Royalty, to satisfy the terms of its credit agreement with HealthCare Royalty Partners III, L.P., a Delaware limited partnership managed by Healthcare Royalty Management, LLC, or HealthCare Royalty; the Company’s ability to obtain and maintain necessary intellectual property protection; development by the Company’s competitors of new or better technological innovations; dependence on key personnel; the Company’s ability to comply with regulatory requirements; 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 makes under its current and potential future collaborations. The results of the Company’s operations may 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; Aurigene’s ability to successfully discover and develop preclinical programs under the Company’s collaboration with Aurigene, as well as the Company’s decision to exclusively license and further develop programs under this collaboration; Roche and Genentech’s ability to successfully commercialize Erivedge; and positive results in Roche and Genentech’s ongoing clinical trials. The Company has incurred losses and negative cash flows from operations since its inception. As of March 31, 2017 , the Company had an accumulated deficit of approximately $914.7 million . The Company anticipates that its $60.8 million of existing cash, cash equivalents and investments at March 31, 2017 should enable it to maintain its planned operations into 2018. In order to ensure adequate cash resources for 12 months from the issuance date of these financial statements, the Company will reduce or delay spending on its research and development programs and operating expenses to the extent it is unable to raise additional financing through its current $30.0 million at-the-market sale agreement with Cowen and Company, LLC, or Cowen or other potential financing. Accordingly, the inability to obtain additional funds in the next 12 months would have a negative impact on the Company’s financial condition and ability to pursue its business strategies. The Company’s ability to raise additional funds will depend 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.

Basis of Presentation

Basis of Presentation	3 Months Ended
	Mar. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation The accompanying condensed consolidated financial statements of the Company have been prepared in accordance with the instructions to Form 10-Q and Article 10 of Regulation S-X. These statements, however, are condensed and do not include all disclosures required by accounting principles generally accepted in the United States, or 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, 2016 as filed with the Securities and Exchange Commission, or the SEC, on March 9, 2017. In the opinion 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 March 31, 2017 and the results of operations for the three -month periods ended March 31, 2017 and 2016 and the cash flows for the three -month periods ended March 31, 2017 and 2016 . The condensed consolidated balance sheet at December 31, 2016 was derived from audited annual financial statements, but does not contain all of the footnote disclosures from the annual financial statements. 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 fair value of the Company’s debt; the collectability of receivables; the carrying value of property and equipment and intangible assets; 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.

Revenue Recognition

Revenue Recognition	3 Months Ended
	Mar. 31, 2017
Accounting Policies [Abstract]
Revenue Recognition	Revenue Recognition The Company is currently a party to a collaboration agreement with Genentech, the terms of which provide for Genentech to make a non-refundable license fee payment, research and development funding payments, contingent cash payments based upon achievement of clinical development and regulatory objectives, and royalties on potential product sales. For a complete discussion of the Company’s revenue recognition policy, see Note 2(c) included in its 2016 Annual Report on Form 10-K.

Collaboration Agreements

Collaboration Agreements	3 Months Ended
	Mar. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Collaboration Agreements	Collaboration Agreements (a) Genentech Collaboration Overview. In June 2003, the Company licensed its proprietary Hedgehog pathway 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 United States 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 March 31, 2017 . Royalty Payments. In addition to these payments and pursuant to the 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, including when a competing product that binds to the same molecular target as Erivedge is approved by the applicable regulatory authority in another country, and is being sold in such country, by a third party for use in the same indication as Erivedge, or, when there is no issued intellectual property covering Erivedge in a territory in which sales are recorded. In 2015, the FDA and the European Medicine Agency’s Committee for Medicinal Products for Human Use, approved another Hedgehog signaling pathway inhibitor, Odomzo® (sonidegib), which is marketed by Novartis (to be acquired by Sun Pharmaceutical Industries Ltd. as announced in December 2016), for use in locally advanced BCC. Beginning in the fourth quarter of 2015 , Genentech applied the 2% royalty reduction on United States sales of Erivedge as a result of the first commercial sale of sonidegib in the United States. In November 2012, the Company formed a wholly-owned subsidiary, Curis Royalty, to receive a $30.0 million loan, at an interest rate of 12.25% , pursuant to a credit agreement between Curis Royalty and BioPharma-II (see Note 7). In connection with the loan, the Company transferred to Curis Royalty its right to receive royalty and royalty-related payments from Genentech. The loan and accrued interest was an obligation of Curis Royalty, with no recourse to the Company, to be repaid using the royalty and royalty-related payments from Genentech. In March 2017, the Company and Curis Royalty, entered into a new credit agreement, with HealthCare Royalty Partners III, L.P., or HealthCare Royalty, for the purpose of refinancing the loan from BioPharma-II. Accordingly, HealthCare Royalty made a $45.0 million loan at an interest rate of 9.95% to Curis Royalty, which was used to pay off $18.4 million in remaining loan obligations to Biopharma-II under the prior loan and the residual proceeds of $26.6 million were distributed to the Company as sole equity member of Curis Royalty. In March 2017, the Company and Curis Royalty entered into a new credit agreement with HealthCare Royalty for the purpose of refinancing a prior loan from BioPharma-II (see Note 7). The loan from HealthCare Royalty will be repaid from certain royalty and royalty-related payments owed by Genentech under the Genentech collaboration agreement, the rights to which were, transferred from Curis to Curis Royalty pursuant to a purchase and sale agreement in 2012, in connection with the prior loan. The Company recognized $2.2 million and $1.7 million in royalty revenue under the Genentech collaboration during the three months ended March 31, 2017 and 2016 , respectively. The Company recorded costs of royalty revenues within the costs and expenses section of its condensed consolidated statements of operations and comprehensive loss of $0.1 million and $0.1 million during the three months ended March 31, 2017 and 2016 , respectively. The amounts for each of these periods, representing 5% of the royalty received from Genentech, account for the Company's obligations to university licensors. As further discussed in Note 7, the Company expects that all royalty revenues received from Genentech on net sales of Erivedge will be used to pay principal and interest under the loan received from HealthCare Royalty, until such time as the loan is fully repaid. The Company recorded research and development revenue of an immaterial amount and $0.1 million during the three months ended March 31, 2017 and 2016 , respectively, related to expenses incurred by the Company on behalf of Genentech that were paid by the Company and for which Genentech is obligated to reimburse the Company. Genentech incurred expenses of $0.1 million during the three months ended March 31, 2017 and 2016 , under this collaboration, which the Company is obligated to reimburse to Genentech, and which the Company has recorded as contra-revenues which have been net against research and development revenues in its Consolidated Statements of Operations and Comprehensive Loss. The Company will continue to recognize revenue for expense reimbursement as such reimbursable expenses are incurred, provided that the provisions of the FASB Codification Topic 605-45 are met. (b) Aurigene Collaboration Overview. 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. 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. For each program, Aurigene has granted the Company an exclusive option, exercisable within 90 days after Aurigene delivers the relevant data regarding a development candidate, to obtain an exclusive, royalty-bearing license to develop, manufacture and commercialize compounds from such program, including the development candidate and products containing such compounds, anywhere in the world, except for India and Russia. For the development, manufacture, and commercialization of compounds from a particular program and products containing such compounds in India and Russia, Aurigene will grant the Company the royalty-bearing license described above for such program, and the Company will grant Aurigene an exclusive, royalty-free, fully paid license under the Company’s relevant technology upon exercise of the relevant option. For each option to license (as described above) exercised by the Company, 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 United States, 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. Subject to specified exceptions, Aurigene and the Company agreed to collaborate exclusively with each other on the discovery, research, development and commercialization of programs and compounds within immuno-oncology for an initial period of approximately two years from the effective date of the collaboration agreement. At the Company's option, and subject to specified conditions, it may extend such exclusivity for up to three additional one -year periods by paying to Aurigene exclusivity option fees on an annual basis. The first of such option fees is $7.5 million , to be paid in two equal installments. In addition, beyond the up-to five years of exclusivity described above, and subject to specified exceptions and payment by the Company of an annual exclusivity fee on a program-by-program basis, Aurigene and the Company have agreed to collaborate exclusively with each other on each program for which there are ongoing activities in research or development, or for which the Company has exercised its option to acquire an exclusive license (as described above) and the Company and its affiliates or sublicensees are actively developing or commercializing a compound or product from such program in a major market. For each product that may be commercialized, the Company has granted Aurigene the right, subject to certain conditions, to nominate one global supplier of drug substance or drug product to provide up to 50% of the total requirements in the Company's territory. As of March 31, 2017 , the Company has exercised its option to license three programs under the collaboration. 1. 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 PDL1 and VISTA. 2. IRAK4 Program. A precision oncology program of small molecule inhibitors of IRAK4. The development candidate is CA-4948, an orally available small molecule inhibitor of IRAK4. 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. The Company anticipates that it may select additional programs under this collaboration in the future, and the Company intends to have the collaboration’s steering committee recommend such additional programs in order for Aurigene to initiate or continue the relevant preclinical activities described in each program’s written plan. In January 2017, the Company extended its collaboration exclusivity with Aurigene and paid the first installment ( $3.75 million ) of this exclusivity option fee. The second installment ( $3.75 million ) of the exclusivity option fee is estimated to be paid in the third quarter of 2017. Up-front Equity Issuance . In connection with the collaboration agreement, the Company issued to Aurigene 17,120,131 shares of its common stock valued at $24.3 million in partial consideration for the rights granted to the Company under the collaboration agreement, which the Company recognized as expense during the year ended December 31, 2015. The shares were issued pursuant to a stock purchase agreement with Aurigene dated January 18, 2015. Research Payments, Option Exercise Fees and Milestone Payments. The Company has agreed to make the following research payments, option exercise fees and milestone payments to Aurigene, except to the extent that such fees and payments have been waived pursuant to the terms of an amendment dated September 7, 2016, which is described below: • for each of the PD1/VISTA and IRAK4 programs: up to $52.5 million per program, comprising: $3.0 million for each option exercise, which the Company incurred and paid during the fourth quarter of 2015, $3.0 million upon acceptance of each IND filing and $4.0 million upon dosing of the fifth patient in the Company's first Phase 1 clinical trial for each program, as well as specified approval and commercial milestones, plus specified additional payments for approvals for additional indications, if any. Effective October 2015, the Company agreed to make additional payments to Aurigene totaling up to $2.0 million for supplemental research, development and/or manufacturing activities in support of these two programs. • Since the inception of the agreement through March 31, 2017 , the Company has paid $11.0 million of the foregoing payments related to the PD1/VISTA and IRAK4 programs under the collaboration. • for each of the PD1/TIM3 program and the fourth program (if exercised): up to $50.0 million per program, comprising $2.0 million for a program selection fee, $3.0 million for an option exercise fee, $2.5 million upon acceptance of an IND filing, as well as specified approval and commercial milestones, plus specified additional payments for approvals for additional indications, if any; • Since the inception of the agreement through March 31, 2017 , the Company has paid $3.5 million of the payments described related to these programs under the collaboration. • for any program thereafter (if any): up to $140.5 million per program, comprising: up to $53.0 million for research fees, an option exercise fee, a preclinical milestone and development milestones, as well as specified filing, approval and commercial milestones, plus specified additional payments for approvals for additional indications, if any. • Since the inception of the agreement through March 31, 2017 , the Company has paid none of these payments related to these programs under the collaboration. Amendment to Collaboration Agreement. On September 7, 2016, the Company and Aurigene entered into an amendment to the collaboration agreement. Under the terms of the amendment, in exchange for the issuance by the Company to Aurigene of 10,208,333 shares of its common stock, Aurigene waived payment of up to a total of $24.5 million in milestones and other payments from the Company that may become due under the collaboration agreement. The following milestones and other payments have been waived: • $1.0 million payment for extended exclusivity related to the IRAK4 program; • $3.0 million payment upon acceptance of IND filing related to the IRAK4 program; • $4.0 million payment upon dosing of the fifth patient in the Company's Phase 1 clinical trial for the IRAK4 program; • $1.0 million payment for extended exclusivity related to the PD1/VISTA program; • $4.0 million payment upon dosing of the fifth patient in the Company's Phase 1 clinical trial for the PD1/VISTA program; • $1.5 million , or 50% , of the payment related to the option exercise payment of the PD1/TIM3 program; • $2.5 million payment upon acceptance of IND filing related to the PD1/TIM3 program; • $2.0 million payment for program selection fee of the fourth program; • $3.0 million payment for option exercise of the fourth program; and • $2.5 million payment upon acceptance of IND filing related to the fourth program; To the extent any of these waived milestone or other payments described above would not otherwise be payable by the Company, e.g. in the event one or more of the listed milestone events do not occur, the Company will have the right to deduct the unused waiver amount from any one or more of the milestone payment obligations tied to achievement of commercial milestone events. The amendment also provides that, the Company will provide up to $2.0 million of additional funding for each such licensed program provided that supplemental program activities are performed by Aurigene.

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2017
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The Company discloses fair value measurements based on a framework outlined by GAAP which requires expanded disclosures regarding fair value measurements. GAAP defines fair value as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Market participants are buyers and sellers in the principal market that are (i) independent, (ii) knowledgeable, (iii) able to transact, and (iv) willing to transact. GAAP also establishes a fair value hierarchy which requires an entity to maximize the use of observable inputs, where available, and minimize the use of unobservable inputs when measuring fair value. The standard describes three levels of inputs that may be used to measure fair value: 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, 2017 and December 31, 2016 of those financial assets and liabilities that are measured at fair value on a recurring basis. Quoted Prices in Active Markets (Level 1) Other Observable Inputs (Level 2) Unobservable Inputs (Level 3) Total Fair Value As of March 31, 2017: Cash equivalents: Money market funds $ 29,358 $ — $ — $ 29,358 Corporate commercial paper, bonds and notes — 8,441 — 8,441 Municipal bonds — 275 — 275 Short-term investments: Corporate commercial paper, stock, bonds and notes — 18,385 — 18,385 Total assets at fair value $ 29,358 $ 27,101 $ — $ 56,459 Quoted Prices in Active Markets (Level 1) Other Observable Inputs (Level 2) Unobservable Inputs (Level 3) Total Fair Value As of December 31, 2016: Cash equivalents: Money market funds $ 24,542 $ — $ — $ 24,542 Corporate commercial paper, bonds and notes — — — — Municipal bonds — 330 — 330 Short-term investments: Corporate commercial paper, stock, bonds and notes — 18,447 — 18,447 Total assets at fair value $ 24,542 $ 18,777 $ — $ 43,319 No investments held at March 31, 2017 were transferred between levels.

Investments

Investments	3 Months Ended
	Mar. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Investments	Investments Cash equivalents are highly liquid investments purchased with original maturities of three months or less. All other liquid investments are classified as marketable securities. The Company’s short-term investments are marketable 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 the Company's long-term investments are marketable 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 government obligations. All of the Company’s short-term and long-term investments have been designated available-for-sale and are stated at fair value with any unrealized holding gains or losses included as a component of stockholders’ equity and any realized gains and losses recorded in the statement of operations in the period during which the securities are sold. 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). Any premium or discount arising at purchase is amortized and/or accreted to interest income. The amortized cost, unrealized gains and losses and fair value of investments available-for-sale as of March 31, 2017 are as follows: Amortized Cost Unrealized Gain Unrealized Loss Total Fair Value Corporate bonds and notes – short-term $ 18,390 $ — $ (5 ) $ 18,385 Total investments $ 18,390 $ — $ (5 ) $ 18,385 Short-term investments have maturities ranging from one to 12 months with a weighted-average maturity of 0.3 years at March 31, 2017 . The amortized cost, unrealized gains and losses and fair value of investments available-for-sale as of December 31, 2016 are as follows: Amortized Cost Unrealized Gain Unrealized Loss Total Fair Value Corporate bonds and notes – short-term $ 18,451 $ 2 $ (6 ) $ 18,447 Total investments $ 18,451 $ 2 $ (6 ) $ 18,447 Short-term investments have maturities ranging from one to 12 months with a weighted-average maturity of 0.2 years at December 31, 2016 . At March 31, 2017 , the Company held 11 debt securities that had been in an unrealized loss position for less than 12 months. The aggregate fair value of these securities was $12.7 million at March 31, 2017 . The Company held no investments that have been in a continuous unrealized loss position for 12 months or longer. The Company evaluated its securities for other-than-temporary impairments based on quantitative and qualitative factors, and we considered the decline in market value for the 11 debt securities held as of March 31, 2017 to be primarily attributable to current economic and market conditions. The Company will likely not be required to sell these securities, and the Company does not intend to sell these securities before the recovery of their amortized cost bases, which recovery is expected within the next 12 months. Based on this analysis, the Company does not consider these investments to be other-than-temporarily impaired as of March 31, 2017 .

Debt

Debt	3 Months Ended
	Mar. 31, 2017
Debt Disclosure [Abstract]
Debt	Debt (a) BioPharma-II In December 2012, Curis’s wholly owned subsidiary, Curis Royalty, received a $30.0 million loan at an annual interest rate of 12.25% pursuant to a credit agreement between Curis Royalty and BioPharma-II. In connection with the loan, Curis transferred to Curis Royalty its right to receive royalty and royalty-related payments on the commercial sales of Erivedge that it receives from Genentech (see Note 4(a)). The loan and accrued interest was being repaid by Curis Royalty using such royalty and royalty-related payments. To secure repayment of the loan, Curis Royalty granted a first priority lien and security interest (subject only to permitted liens) to BioPharma-II in all of its assets and all real, intangible and personal property, including all of its right, title and interest in and to the royalty and royalty-related payments. The loan constituted an obligation of Curis Royalty, and was non-recourse to Curis. Under the terms of the loan, quarterly royalty payments received by Curis Royalty from Genentech were first applied to pay (i) escrow fees payable by Curis pursuant to an escrow agreement between Curis, Curis Royalty, BioPharma-II and Boston Private Bank and Trust Company, (ii) Curis's royalty obligations to university licensors, (iii) certain expenses incurred by BioPharma-II in connection with the credit agreement and related transaction documents, including enforcement of its rights in the case of an event of default under the credit agreement and (iv) expenses incurred by Curis enforcing its right to indemnification under the collaboration agreement with Genentech. Remaining amounts were applied first to pay interest and second, principal on the loan. Curis remained entitled to receive any contingent payments upon achievement of clinical development objectives. Curis Royalty retained its right to royalty payments related to sales of Erivedge following repayment of the loan. The final maturity date of the loan was the earlier of the date when the principal was paid in full or the termination of Curis Royalty’s right to receive royalties under the collaboration agreement with Genentech. Because the repayment of the term loan was contingent upon the level of Erivedge royalties received, the short- and long-term classification of the debt was based on the Company’s estimate of the timing of amounts to be repaid. The Company was not able estimate when the loan would be repaid as repayment s impacted by numerous factors, all of which were beyond the Company’s control. The repayment term could be shortened or extended depending on the actual level of Erivedge royalties received. In addition, if Erivedge royalties were insufficient to pay the accrued interest on the outstanding loan, any unpaid interest outstanding would be added to the principal on a quarterly basis. At any time after January 1, 2017, Curis Royalty was entitled to, subject to certain limitations, to prepay the outstanding principal of the loan in whole or in part, at a price equal to 105% of the outstanding principal on the loan, plus accrued but unpaid interest. (b) HealthCare Royalty Partners III On March 6, 2017, the Company and Curis Royalty entered into a credit agreement, referred to herein as the credit agreement, with HealthCare Royalty for the purpose of refinancing Curis’s and Curis Royalty’s existing royalty financing arrangement with BioPharma-II, referred to herein as the prior loan, with BioPharma-II. On March 22, 2017, the prior loan was terminated in its entirety. Pursuant to the credit agreement, HealthCare Royalty made a $45.0 million loan at an interest rate of 9.95% to Curis Royalty, which was used to pay off $18.4 million in remaining loan obligations to Biopharma-II under the prior loan. The remaining proceeds of $26.6 million were distributed to Curis as sole equity holder of Curis Royalty. The loan from HealthCare Royalty will be repaid from certain Erivedge royalty and royalty-related payments owed by Genentech under the Genentech collaboration agreement, the rights to which were transferred from Curis to Curis Royalty in 2012. Under the terms of the credit agreement with HealthCare Royalty, quarterly Erivedge royalty and royalty-related payments from Genentech will first be applied to pay (i) escrow fees payable by the Company pursuant to an escrow agreement, (ii) the Company’s royalty obligations to academic institutions, (iii) certain expenses incurred by HealthCare Royalty in connection with the credit agreement and related transaction documents, including enforcement of its rights in the case of an event of default under the credit agreement and (iv) expenses incurred by the Company enforcing its right to indemnification under the collaboration agreement. Remaining amounts will be applied first, to pay interest and second, to pay principal on the loan. If royalties owed under the Genentech collaboration agreement are insufficient to pay the accrued interest on the outstanding loan, the unpaid interest outstanding will be added to the loan principal on a quarterly basis. (c) Respective Debt Payments to BioPharma-II and HealthCare Royalty Partners III During the three months ended March 31, 2017 and 2016 , Curis Royalty made payments totaling $2.4 million and $1.9 million , respectively, of which $1.7 million and $1.2 million have been applied to the principal, respectively, with the remainder applied to accrued interest. As of March 31, 2017 , the Company recorded short- and long-term debt of $3.5 million and $41.3 million , respectively, and at December 31, 2016 , the Company recorded short- and long-term debt of $4.9 million and $14.9 million , respectively, with such amounts recorded within the Company’s condensed consolidated balance sheets. In addition, the Company recorded related accrued interest on its debt of $0.1 million and $0.2 million as of March 31, 2017 and December 31, 2016 , respectively, with such amounts included in the Company’s accrued liabilities section of its condensed consolidated balance sheets. For the three months ended March 31, 2017 and 2016 , the Company recognized interest expense related to its debt of $0.7 million and $0.7 million , respectively, in the condensed consolidated statement of operations and comprehensive loss. At March 31, 2017 , the fair value of the debt approximates its carrying value due to the expected repayment period and because the interest rate yield is near current market rate yields. Due to the assumptions required in estimating future Erivedge royalties, the expected repayment period and weighting of various royalty projection scenarios, the fair value of the debt is measured using Level 3 inputs. During the three months ended March 31, 2017 , the Company incurred debt issuance costs totaling $0.2 million in connection with its HealthCare Royalty financing transaction, all of which were incurred directly by the Company. The direct costs incurred by the Company were recorded as contra-debt, which directly reduces the outstanding debt balance on the Company's Consolidated Balance Sheet. All issuance costs will be amortized over the estimated term of the debt using the straight-line method, which approximates the effective interest method. The assumptions used in determining the expected repayment term of the debt and amortization period of the issuance costs requires management to make estimates that could impact the Company’s short- and long-term classification of these costs, as well as the period over which these costs will be amortized. Future payments of principal on the loan will require application of the same assumptions described above and will be used to estimate short- and long-term classification of the debt within the Company’s consolidated balance sheets. At March 31, 2017 , the Company estimates that its future payments of principal on the loan are as follows: Principal 2017 $ 2,348 2018 4,325 2019 5,780 2020 7,137 2021 8,599 2022 10,058 Thereafter 6,753 Total payments 45,000 Less current portion, gross (3,533 ) Total long-term debt obligations, gross $ 41,467

Accrued Liabilities

Accrued Liabilities	3 Months Ended
	Mar. 31, 2017
Other Liabilities Disclosure [Abstract]
Accrued Liabilities	Accrued Liabilities Accrued liabilities consist of the following: March 31, December 31, Accrued compensation $ 1,052 $ 2,026 Professional fees 158 157 Accrued interest on debt (Note 7) 112 194 Other 251 348 Total $ 1,573 $ 2,725

Accounting for Stock-Based Comp

Accounting for Stock-Based Compensation	3 Months Ended
	Mar. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Accounting for Stock-Based Compensation	Accounting for Stock-Based Compensation As of March 31, 2017 , the Company had two shareholder-approved, share-based compensation plans: (i) the Amended and Restated 2010 Stock Incentive Plan, or the 2010 Plan, adopted by the board of directors in March 2015 and approved by shareholders in May 2015 and (ii) the 2010 Employee Stock Purchase Plan, or the ESPP, adopted by the board of directors in April 2010 and approved by shareholders in June 2010. New employees are typically issued options as an inducement equity award under NASDAQ Listing Rule 5635(c)(4) outside of the 2010 Plan. During the three months ended March 31, 2017 , the Company’s board of directors granted options to purchase a total of 4,814,000 shares of the Company’s common stock to officers and employees of the Company, under the 2010 Plan or in the form of inducement awards pursuant to NASDAQ Marketplace Rules. These options generally vest 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 price of the Company’s common stock on the NASDAQ Global Market on the grant dates. During the three months ended March 31, 2017 , the Company’s board of directors also granted options to its non-employee directors to purchase 840,000 shares of common stock under the 2010 Plan, which will vest and become exercisable in equal monthly installments over a period of one year from the date of grant. These options were granted at an exercise price of $2.31 per share, which equals the closing market price of the Company’s common stock on the NASDAQ Global Market on the grant date. Employee and Director Grants Vesting Tied to Service Conditions In determining the fair value of stock options, the Company generally uses the Black-Scholes option pricing model. As discussed below, for employee stock options with market performance conditions, the Company uses a Monte Carlo simulation valuation model. The Black-Scholes option pricing model employs the following key assumptions for employee and director options awarded during the three months ended March 31, 2017 and 2016 based on the assumptions noted in the following table: Three Months Ended 2017 2016 Expected life (years) - employees 5.5 6 Expected life (years) - officers 5.5 6 Expected life (years) – directors 6.25 7 Risk-free interest rate 2.1% 1.6-1.8% Volatility 63-64% 69-70% Dividends None None The expected volatility is based on the annualized daily historical volatility of the Company’s stock price for a time period consistent with the expected term of each grant. Management believes that the historical volatility of the Company’s stock price best represents the future volatility of the stock price. The risk-free interest rate is based on the U.S. Treasury yield in effect at the time of grant for the expected term of the respective grant. The Company has not historically paid cash dividends, and does not expect to pay cash dividends in the foreseeable future. The expected terms and stock price volatility utilized in the calculation involve management’s best estimates at that time, both of which impact the fair value of the option calculated under the Black-Scholes methodology and, ultimately, the expense that will be recognized over the life of the option. GAAP also requires that the Company recognize compensation expense for only the portion of options that are expected to vest. Therefore, management calculated an estimated annual pre-vesting forfeiture rate that is derived from historical employee termination behavior since the inception of the Company, as adjusted. If the actual number of forfeitures differs from those estimated by management, additional adjustments to compensation expense may be required in future periods. A summary of stock option activity under the Amended and Restated 2010 Plan, the 2000 Stock Incentive Plan, the 2000 Director Stock Option Plan and nonstatutory inducement awards is summarized as follows: Number of Shares Weighted Average Exercise Price per Share Weighted Average Remaining Contractual Life Aggregate Intrinsic Value Outstanding, December 31, 2016 13,752,157 $ 2.30 Granted 5,654,000 2.52 Exercised (449,152 ) 1.42 Canceled (258,003 ) 3.10 Outstanding, March 31, 2017 18,699,002 $ 2.37 7.74 $ 10,598 Exercisable at March 31, 2017 7,665,796 $ 2.59 5.58 $ 4,218 Vested and unvested expected to vest 17,557,600 $ 2.38 7.62 $ 10,020 The weighted average grant-date fair values of these stock options granted during the three months ended March 31, 2017 and 2016 were $2.52 and $1.07 , respectively. As of March 31, 2017 , there was approximately $12.5 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 2.89 years. The intrinsic value of employee stock options exercised during the three months ended March 31, 2017 and 2016 was $0.7 million and $0.1 million , respectively. Employee Stock-Based Compensation Expense The Company recorded a total of $1.1 million in compensation expense for the three months ended March 31, 2017 and $0.9 million in compensation expense for the three months ended March 31, 2016 related to employee and director stock option grants. The total fair values of vested stock options for each of the three months ended March 31, 2017 and 2016 was $1.5 million . Non-Employee Grants The Company has periodically granted stock options to consultants for services pursuant to the Company’s stock plans at the fair market value on the respective dates of grant. Should the Company terminate any of its consulting agreements, the unvested options underlying the agreements would also be canceled. The Company recognized an immaterial expense related to non-employee stock options during the three months ended March 31, 2017 and reversed expense of $0.1 million during the three months ended March 31, 2016 . Total Stock-Based Compensation Expense For the three months ended March 31, 2017 and 2016 , 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 2017 2016 Research and development expenses $ 289 $ 122 General and administrative expenses 814 650 Total stock-based compensation expense $ 1,103 $ 772

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income (Loss)	3 Months Ended
	Mar. 31, 2017
Equity [Abstract]
Accumulated Other Comprehensive Income (Loss)	Accumulated Other Comprehensive Income (Loss) The following table summarizes the changes in accumulated other comprehensive income (loss) as of March 31, 2017 and 2016 : Unrealized Gain on Securities Available-for-Sale Balance, as of December 31, 2016 $ (4 ) Unrealized gain on marketable securities (2 ) Amounts reclassified from accumulated other comprehensive income (loss) — Net current period other comprehensive income (2 ) Balance, as of March 31, 2017 $ (6 ) The above amounts do not reflect a tax effect because the Company expects to record a net loss for 2017 . Unrealized Losses and Gain on Securities Available-for-Sale Balance, as of December 31, 2015 $ 28 Unrealized gain on marketable securities 32 Amounts reclassified from accumulated other comprehensive income (loss) — Net current period other comprehensive income 32 Balance, as of March 31, 2016 $ 60

Common Stock

Common Stock	3 Months Ended
	Mar. 31, 2017
Equity [Abstract]
Common Stock	Common Stock On July 2, 2015, the Company entered into a sales agreement with Cowen and Company, LLC, or Cowen, pursuant to which the Company may sell from time to time up to $30.0 million of the Company’s common stock through an “at-the-market” equity offering program under which Cowen will act as sales agent. Subject to the terms and conditions of the sales agreement, Cowen may sell the common stock by methods deemed to be an “at-the-market” offering as defined in Rule 415 promulgated under the Securities Act of 1933, as amended. In addition, with the Company’s prior written approval, Cowen may also sell the common stock by any other method permitted by law, including pursuant to negotiated transactions. Cowen is obligated to use its commercially reasonable efforts consistent with its normal trading and sales practices and applicable state and federal laws, rules and regulations and the rules of the NASDAQ Global Market to sell on the Company’s behalf all of the shares requested to be sold by the Company. The Company has no obligation to sell any of the common stock under the sales agreement. Either the Company or Cowen may at any time suspend solicitations and offers under the sales agreement upon notice to the other party. The sales agreement may be terminated at any time by either the Company or Cowen upon written notice to the other party as specified in the sales agreement. The aggregate compensation payable to Cowen shall be 3% of the gross sales price of the common stock sold by Cowen pursuant to the sales agreement. Each party has agreed in the sales agreement to provide indemnification and contribution against certain liabilities, including liabilities under the Securities Act, subject to the terms of the sales agreement. The shares to be sold under the sales agreement, if any, will be issued and sold pursuant to the currently-effective universal shelf registration statement on Form S-3, filed with the Securities and Exchange Commission on July 2, 2015. For the three months ending March 31, 2017 , the Company sold 2,103,981 shares of common stock under this sales agreement for net proceeds of $6.2 million .

Loss Per Common Share

Loss Per Common Share	3 Months Ended
	Mar. 31, 2017
Earnings Per Share [Abstract]
Loss Per Common Share	Loss Per Common Share Basic 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 three months ended March 31, 2017 and 2016 , 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 only of stock options outstanding of 18,699,002 and 17,481,007 as of March 31, 2017 and 2016 , respectively.

New Accounting Pronouncements

New Accounting Pronouncements	3 Months Ended
	Mar. 31, 2017
Accounting Changes and Error Corrections [Abstract]
New Accounting Pronouncements	New Accounting Pronouncements In January 2017, the Financial Accounting Standard Board (FASB) issued Accounting Standard Update (ASU) 2017-04, Simplifying the Test for Goodwill Impairment , which simplifies the subsequent measurement of goodwill under the current standard in testing the interim or annual impairment of goodwill. The standard will be effective for annual reporting periods and interim periods within those annual periods, beginning after December 15, 2019, and early adoption is permitted for interim or annual period beginning after January 1, 2017. The Company does not expect this guidance to have a material impact on its consolidated financial statements. In March 2016, the FASB issued ASU 2016-09, Improvements to Employee Share-Based Payment Accounting , which simplifies share-based payment accounting through a variety of amendments. The standard will be effective for annual reporting periods and interim periods within those annual periods, beginning after December 15, 2016, as such, the Company adopted the standard as of March 31, 2017 . One of the optional amendments of this standard that affect the Company relates to the adoption of removing the application of a forfeiture rate when recording stock-based compensation. The Company has concluded that it will not be changing the historical application of estimated forfeiture rates. In February 2016, the FASB issued ASU 2016-02, Leases . The standard requires organizations that lease assets to recognize on the balance sheet assets or liabilities, as applicable, for the rights and obligations created by those leases. Additionally, the guidance modifies current guidance for lessor accounting and leveraged leases, and is effective for fiscal years beginning after December 15, 2018, and interim periods within such years. Early adoption is permitted, but the Company does not anticipate electing early adoption. The Company is currently evaluating the impact of the adoption of this guidance on its consolidated financial statements. In January 2016, the FASB issued ASU 2016-01, Recognition and Measurement of Financial Assets and Financial Liabilities, which amends prior guidance on accounting for equity investments and financial liabilities. The new standard amends certain aspects of accounting and disclosure requirements for financial instruments, including the requirement that equity investments with readily determinable fair values be measured at fair value with changes in fair value recognized in results of operations. The new standard does not apply to investments accounted for under the equity method of accounting or those that result in consolidation of the investee. Equity investments that do not have readily determinable fair values may be measured at fair value or at cost minus impairment adjusted for changes in observable prices. A financial liability that is measured at fair value in accordance with the fair value option is required to be presented separately in other comprehensive income for the portion of the total change in the fair value resulting from change in the instrument-specific credit risk. In addition, a valuation allowance should be evaluated on deferred tax assets related to available-for-sale debt securities in combination with other deferred tax assets. The guidance is effective for fiscal years beginning after December 15, 2017, and interim periods within such years. Early adoption is permitted but the Company does not anticipate electing early adoption. The Company does not expect the adoption of this guidance to have a material impact on its consolidated financial statements. In May 2014, the FASB issued new revenue recognition guidance in ASC 606, Revenue from Contracts with Customers, for entities, providing a single, comprehensive model to account for revenue arising from contracts with customers. In addition, The FASB recently issued ASUs 2016-08, 2016-10, 2016-12, 2016-20 and 2017-05, all of which are further clarifying amendments to ASU 2014-09. The new standard requires significantly expanded disclosures regarding the qualitative and quantitative information of an entity’s nature, amount, timing, and uncertainty of revenue and cash flows arising from contracts with customers. The guidance is anticipated to be effective for the Company in 2018. Early adoption is permitted in 2017. The Company does not expect the adoption of this guidance to have a material impact on its consolidated financial statements.

New Accounting Pronouncements (

New Accounting Pronouncements (Policies)	3 Months Ended
	Mar. 31, 2017
Accounting Changes and Error Corrections [Abstract]
Fair Value Measurements	The Company discloses fair value measurements based on a framework outlined by GAAP which requires expanded disclosures regarding fair value measurements. GAAP defines fair value as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Market participants are buyers and sellers in the principal market that are (i) independent, (ii) knowledgeable, (iii) able to transact, and (iv) willing to transact. GAAP also establishes a fair value hierarchy which requires an entity to maximize the use of observable inputs, where available, and minimize the use of unobservable inputs when measuring fair value. The standard describes three levels of inputs that may be used to measure fair value: 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.
Basic and Diluted Loss Per Common Share	Basic 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 three months ended March 31, 2017 and 2016 , because the effect of the potential common stock equivalents would be antidilutive due to the Company’s net loss position for these periods.
New Accounting Pronouncements	In March 2016, the FASB issued ASU 2016-09, Improvements to Employee Share-Based Payment Accounting , which simplifies share-based payment accounting through a variety of amendments. The standard will be effective for annual reporting periods and interim periods within those annual periods, beginning after December 15, 2016, as such, the Company adopted the standard as of March 31, 2017 . One of the optional amendments of this standard that affect the Company relates to the adoption of removing the application of a forfeiture rate when recording stock-based compensation. The Company has concluded that it will not be changing the historical application of estimated forfeiture rates. In February 2016, the FASB issued ASU 2016-02, Leases . The standard requires organizations that lease assets to recognize on the balance sheet assets or liabilities, as applicable, for the rights and obligations created by those leases. Additionally, the guidance modifies current guidance for lessor accounting and leveraged leases, and is effective for fiscal years beginning after December 15, 2018, and interim periods within such years. Early adoption is permitted, but the Company does not anticipate electing early adoption. The Company is currently evaluating the impact of the adoption of this guidance on its consolidated financial statements. In January 2016, the FASB issued ASU 2016-01, Recognition and Measurement of Financial Assets and Financial Liabilities, which amends prior guidance on accounting for equity investments and financial liabilities. The new standard amends certain aspects of accounting and disclosure requirements for financial instruments, including the requirement that equity investments with readily determinable fair values be measured at fair value with changes in fair value recognized in results of operations. The new standard does not apply to investments accounted for under the equity method of accounting or those that result in consolidation of the investee. Equity investments that do not have readily determinable fair values may be measured at fair value or at cost minus impairment adjusted for changes in observable prices. A financial liability that is measured at fair value in accordance with the fair value option is required to be presented separately in other comprehensive income for the portion of the total change in the fair value resulting from change in the instrument-specific credit risk. In addition, a valuation allowance should be evaluated on deferred tax assets related to available-for-sale debt securities in combination with other deferred tax assets. The guidance is effective for fiscal years beginning after December 15, 2017, and interim periods within such years. Early adoption is permitted but the Company does not anticipate electing early adoption. The Company does not expect the adoption of this guidance to have a material impact on its consolidated financial statements. In May 2014, the FASB issued new revenue recognition guidance in ASC 606, Revenue from Contracts with Customers, for entities, providing a single, comprehensive model to account for revenue arising from contracts with customers. In addition, The FASB recently issued ASUs 2016-08, 2016-10, 2016-12, 2016-20 and 2017-05, all of which are further clarifying amendments to ASU 2014-09. The new standard requires significantly expanded disclosures regarding the qualitative and quantitative information of an entity’s nature, amount, timing, and uncertainty of revenue and cash flows arising from contracts with customers. The guidance is anticipated to be effective for the Company in 2018. Early adoption is permitted in 2017. The Company does not expect the adoption of this guidance to have a material impact on its consolidated financial statements.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2017
Fair Value Disclosures [Abstract]
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 March 31, 2017 and December 31, 2016 of those financial assets and liabilities that are measured at fair value on a recurring basis. Quoted Prices in Active Markets (Level 1) Other Observable Inputs (Level 2) Unobservable Inputs (Level 3) Total Fair Value As of March 31, 2017: Cash equivalents: Money market funds $ 29,358 $ — $ — $ 29,358 Corporate commercial paper, bonds and notes — 8,441 — 8,441 Municipal bonds — 275 — 275 Short-term investments: Corporate commercial paper, stock, bonds and notes — 18,385 — 18,385 Total assets at fair value $ 29,358 $ 27,101 $ — $ 56,459 Quoted Prices in Active Markets (Level 1) Other Observable Inputs (Level 2) Unobservable Inputs (Level 3) Total Fair Value As of December 31, 2016: Cash equivalents: Money market funds $ 24,542 $ — $ — $ 24,542 Corporate commercial paper, bonds and notes — — — — Municipal bonds — 330 — 330 Short-term investments: Corporate commercial paper, stock, bonds and notes — 18,447 — 18,447 Total assets at fair value $ 24,542 $ 18,777 $ — $ 43,319

Investments (Tables)

Investments (Tables)	3 Months Ended
	Mar. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Summary of Amortized Cost, Unrealized Gains and Losses and Fair Value of Investments	The amortized cost, unrealized gains and losses and fair value of investments available-for-sale as of December 31, 2016 are as follows: Amortized Cost Unrealized Gain Unrealized Loss Total Fair Value Corporate bonds and notes – short-term $ 18,451 $ 2 $ (6 ) $ 18,447 Total investments $ 18,451 $ 2 $ (6 ) $ 18,447 The amortized cost, unrealized gains and losses and fair value of investments available-for-sale as of March 31, 2017 are as follows: Amortized Cost Unrealized Gain Unrealized Loss Total Fair Value Corporate bonds and notes – short-term $ 18,390 $ — $ (5 ) $ 18,385 Total investments $ 18,390 $ — $ (5 ) $ 18,385

Debt (Tables)

Debt (Tables)	3 Months Ended
	Mar. 31, 2017
Debt Disclosure [Abstract]
Contractual Obligation, Fiscal Year Maturity Schedule [Table Text Block]	Future payments of principal on the loan will require application of the same assumptions described above and will be used to estimate short- and long-term classification of the debt within the Company’s consolidated balance sheets. At March 31, 2017 , the Company estimates that its future payments of principal on the loan are as follows: Principal 2017 $ 2,348 2018 4,325 2019 5,780 2020 7,137 2021 8,599 2022 10,058 Thereafter 6,753 Total payments 45,000 Less current portion, gross (3,533 ) Total long-term debt obligations, gross $ 41,467

Accrued Liabilities (Tables)

Accrued Liabilities (Tables)	3 Months Ended
	Mar. 31, 2017
Other Liabilities Disclosure [Abstract]
Schedule of Accrued Liabilities	Accrued liabilities consist of the following: March 31, December 31, Accrued compensation $ 1,052 $ 2,026 Professional fees 158 157 Accrued interest on debt (Note 7) 112 194 Other 251 348 Total $ 1,573 $ 2,725

Accounting for Stock-Based Co24

Accounting for Stock-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Summary of Key Assumptions for Options Awarded	The Black-Scholes option pricing model employs the following key assumptions for employee and director options awarded during the three months ended March 31, 2017 and 2016 based on the assumptions noted in the following table: Three Months Ended 2017 2016 Expected life (years) - employees 5.5 6 Expected life (years) - officers 5.5 6 Expected life (years) – directors 6.25 7 Risk-free interest rate 2.1% 1.6-1.8% Volatility 63-64% 69-70% Dividends None None
Summary of Stock Option Activity	A summary of stock option activity under the Amended and Restated 2010 Plan, the 2000 Stock Incentive Plan, the 2000 Director Stock Option Plan and nonstatutory inducement awards is summarized as follows: Number of Shares Weighted Average Exercise Price per Share Weighted Average Remaining Contractual Life Aggregate Intrinsic Value Outstanding, December 31, 2016 13,752,157 $ 2.30 Granted 5,654,000 2.52 Exercised (449,152 ) 1.42 Canceled (258,003 ) 3.10 Outstanding, March 31, 2017 18,699,002 $ 2.37 7.74 $ 10,598 Exercisable at March 31, 2017 7,665,796 $ 2.59 5.58 $ 4,218 Vested and unvested expected to vest 17,557,600 $ 2.38 7.62 $ 10,020
Schedule of Recorded Stock-Based Compensation Expense	For the three months ended March 31, 2017 and 2016 , 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 2017 2016 Research and development expenses $ 289 $ 122 General and administrative expenses 814 650 Total stock-based compensation expense $ 1,103 $ 772

Accumulated Other Comprehensi25

Accumulated Other Comprehensive Income (Loss) (Tables)	3 Months Ended
	Mar. 31, 2017
Equity [Abstract]
Summary of Changes in Accumulated Other Comprehensive Income (Loss)	The following table summarizes the changes in accumulated other comprehensive income (loss) as of March 31, 2017 and 2016 : Unrealized Gain on Securities Available-for-Sale Balance, as of December 31, 2016 $ (4 ) Unrealized gain on marketable securities (2 ) Amounts reclassified from accumulated other comprehensive income (loss) — Net current period other comprehensive income (2 ) Balance, as of March 31, 2017 $ (6 ) The above amounts do not reflect a tax effect because the Company expects to record a net loss for 2017 . Unrealized Losses and Gain on Securities Available-for-Sale Balance, as of December 31, 2015 $ 28 Unrealized gain on marketable securities 32 Amounts reclassified from accumulated other comprehensive income (loss) — Net current period other comprehensive income 32 Balance, as of March 31, 2016 $ 60

Nature of Business (Details)

Nature of Business (Details)	3 Months Ended
	Mar. 31, 2017USD ($)segmentcandidate	Dec. 31, 2016USD ($)	Oct. 31, 2016program	Oct. 31, 2015program	Jul. 02, 2015USD ($)	Jan. 31, 2015program
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Number of pre-IND stage oncology drug candidates | candidate	2
Reportable segments | segment	1
Retained earnings (accumulated deficit)	$ (914,690,000)	$ (898,948,000)
Cash, cash equivalents and investments	60,800,000
Aurigene
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration agreement, number of programs licensed | program			3	2		2
Cowen | At-the-market sale facility | Maximum
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Planned proceeds from sale of stock	$ 30,000,000				$ 30,000,000

Collaboration Agreements (Detai

Collaboration Agreements (Details)

Mar. 22, 2017USD ($)

Sep. 07, 2016USD ($)shares

Jan. 31, 2017USD ($)

Jan. 31, 2015USD ($)programshares

Jun. 30, 2003USD ($)

Sep. 30, 2017USD ($)

Mar. 31, 2017USD ($)

Jun. 30, 2016USD ($)

Mar. 31, 2016USD ($)

Dec. 31, 2015paymentrightproductterm

Mar. 31, 2015USD ($)

Dec. 31, 2016USD ($)

Dec. 31, 2015USD ($)paymentrightproductterm

Mar. 31, 2017USD ($)

Mar. 06, 2017USD ($)

Oct. 31, 2016program

Oct. 31, 2015USD ($)program

Dec. 31, 2012USD ($)

Nov. 30, 2012USD ($)

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Distribution of remaining loan proceeds

$ 26,600,000

Recognized royalty revenue

$ 2,191,000

$ 1,744,000

Cost of royalty revenues

111,000

89,000

Collaboration agreement, number of optional additional terms | term

3

3

Collaboration agreement, optional additional term

1 year

Option fees

$ 7,500,000

Number of payments | payment

2

2

Value of common stock issued

1,449,000

$ 1,423,000

$ 1,449,000

Curis Royalty, LLC | Credit agreement with BioPharma-II

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Principal loan amount to Curis Royalty given by BioPharma under credit agreement

$ 30,000,000

$ 30,000,000

Interest rate on loan to Curis Royalty given by BioPharma under credit agreement

12.25%

12.25%

Genentech, Inc.

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Amount received for specified clinical development and regulatory objectives

59,000,000

59,000,000

Percentage of royalty rate decrease

2.00%

2.00%

Recognized royalty revenue

2,200,000

1,700,000

Cost of royalty revenues

$ 100,000

$ 100,000

Percentage of royalties earned

5.00%

5.00%

Genentech, Inc. | Drug development royalty

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Research and development revenue

$ 100,000

Research and development expenses

$ 100,000

100,000

Genentech, Inc. | Maximum

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Eligible to receive contingent cash payment for specified clinical development and regulatory objectives (up to)

$ 115,000,000

Percentage of royalty on net sales

7.50%

Genentech, Inc. | Minimum

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Percentage of royalty on net sales

5.00%

HealthCare Royalty Partners III, L.P.

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Remaining loan obligations

$ 45,000,000

45,000,000

HealthCare Royalty Partners III, L.P. | Curis Royalty, LLC

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Principal loan amount to Curis Royalty given by BioPharma under credit agreement

$ 45,000,000

Interest rate on loan to Curis Royalty given by BioPharma under credit agreement

9.95%

BioPharma-II | Curis Royalty, LLC

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Remaining loan obligations

$ 18,400,000

Aurigene

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Collaboration agreement, option exercisable period

90 days

Collaboration agreement, number of programs licensed | program

2

3

2

Additional payments made under collaborative arrangements (up to)

$ 2,000,000

Payments for research and development

$ 1,000,000

$ 1,000,000

Collaboration agreement, number of products required to commercialize (at least) | product

1

1

Collaboration agreement period

2 years

Collaboration agreement, rights granted to nominate global drug substance or drug product supplier | right

1

1

Paid first installment of exclusivity option fee

$ 3,750,000

Issued shares of common stock (in shares) | shares

17,120,131

Value of common stock issued

$ 24,300,000

Shares issued of common stock in exchange for waived payment (in shares) | shares

10,208,333

Waived payment of milestone and other payments (up to)

$ 24,500,000

Aurigene | Forecast

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Paid first installment of exclusivity option fee

$ 3,750,000

Aurigene | PD1/VISTA programs

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Collaboration agreement expenses, option exercise

3,000,000

Collaboration agreement expenses, acceptance of IND filing

3,000,000

Collaboration agreement expenses, dosing of fifth patient

4,000,000

Aurigene | IRAK4 programs

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Collaboration agreement payment

$ 3,000,000

Collaboration agreement expenses, option exercise

3,000,000

Collaboration agreement expenses, acceptance of IND filing

3,000,000

Collaboration agreement expenses, dosing of fifth patient

4,000,000

Aurigene | Programs one and two

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Payments made under collaboration arrangements

11,000,000

Aurigene | Programs three and four

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Payments made under collaboration arrangements

3,500,000

Agreement to provide additional funding, if options are exercised (up to)

2,000,000

Aurigene | Program three

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Collaboration agreement expenses, option exercise

3,000,000

Collaboration agreement expenses, acceptance of IND filing

2,500,000

Collaboration agreement expenses, program selection fee

2,000,000

Aurigene | Program four

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Collaboration agreement expenses, option exercise

3,000,000

Collaboration agreement expenses, acceptance of IND filing

2,500,000

Collaboration agreement expenses, program selection fee

2,000,000

Aurigene | Program thereafter

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Payments made under collaboration arrangements

$ 0

Collaboration agreement, fees (up to)

53,000,000

Aurigene | Extended exclusivity, IRAK4 program

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Waived payment of milestone and other payments (up to)

1,000,000

Aurigene | Acceptance of IND filing, IRAK4 program

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Waived payment of milestone and other payments (up to)

3,000,000

Aurigene | Phase 1 clinical trial, dosing of fifth patient, IRAK4 program

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Waived payment of milestone and other payments (up to)

4,000,000

Aurigene | Extended exclusivity, PD1/VISTA program

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Waived payment of milestone and other payments (up to)

1,000,000

Aurigene | Phase 1 clinical trial, dosing of fifth patient, PD1/VISTA

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Waived payment of milestone and other payments (up to)

4,000,000

Aurigene | Option exercise payment, program three

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Waived payment of milestone and other payments (up to)

$ 1,500,000

Percentage of consideration received

50.00%

Aurigene | Acceptance of IND filing, program three

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Waived payment of milestone and other payments (up to)

$ 2,500,000

Aurigene | Program selection fee, program four

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Waived payment of milestone and other payments (up to)

2,000,000

Aurigene | Option exercise payment, program four

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Waived payment of milestone and other payments (up to)

3,000,000

Aurigene | Acceptance of IND filing, program four

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Waived payment of milestone and other payments (up to)

$ 2,500,000

Aurigene | Maximum

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Collaboration agreement period

5 years

Percentage of contribution (up to)

50.00%

50.00%

Aurigene | Maximum | PD1/VISTA programs

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Collaboration agreement payment

$ 3,000,000

Collaboration agreement, payment per program (up to)

52,500,000

Aurigene | Maximum | IRAK4 programs

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Collaboration agreement, payment per program (up to)

52,500,000

Aurigene | Maximum | Program three

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Collaboration agreement, payment per program (up to)

50,000,000

Aurigene | Maximum | Program four

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Collaboration agreement, payment per program (up to)

$ 50,000,000

Aurigene | Maximum | Program thereafter

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Collaboration agreement, payment per program (up to)

$ 140,500,000

Fair Value Measurements - Finan

Fair Value Measurements - Financial Assets or Liabilities Measured at Fair Value on Recurring Basis (Details) - Fair value measurements, recurring - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Short-term investments:
Total assets at fair value	$ 56,459	$ 43,319
Short-term investments | Corporate commercial paper, stock, bonds and notes
Short-term investments:
Corporate commercial paper, stock, bonds and notes	18,385	18,447
Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	29,358	24,542
Corporate commercial paper, bonds and notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	8,441	0
Municipal bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	275	330
Quoted Prices in Active Markets (Level 1)
Short-term investments:
Total assets at fair value	29,358	24,542
Quoted Prices in Active Markets (Level 1) | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	29,358	24,542
Other Observable Inputs (Level 2)
Short-term investments:
Total assets at fair value	27,101	18,777
Other Observable Inputs (Level 2) | Short-term investments | Corporate commercial paper, stock, bonds and notes
Short-term investments:
Corporate commercial paper, stock, bonds and notes	18,385	18,447
Other Observable Inputs (Level 2) | Corporate commercial paper, bonds and notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	8,441	0
Other Observable Inputs (Level 2) | Municipal bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	$ 275	$ 330

Investments - Summary of Amorti

Investments - Summary of Amortized Cost, Unrealized Gains and Losses and Fair Value of Investments (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 18,390	$ 18,451
Unrealized Gain	0	2
Unrealized Loss	(5)	(6)
Total Fair Value	18,385	18,447
Corporate bonds and notes – short-term | Short-term investments
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	18,390	18,451
Unrealized Gain	0	2
Unrealized Loss	(5)	(6)
Total Fair Value	$ 18,385	$ 18,447

Investments - Narrative (Detai

Investments - Narrative (Details) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2017USD ($)security	Dec. 31, 2016
Debt securities
Schedule of Available-for-sale Securities [Line Items]
Number of securities in an unrealized loss position for less than 12 months | security	11
Fair value of securities in an unrealized loss position for less than 12 months | $	$ 12.7
Short-term investments
Schedule of Available-for-sale Securities [Line Items]
Short-term investments, weighted average maturity	3 months	2 months
Minimum | Short-term investments
Schedule of Available-for-sale Securities [Line Items]
Short-term investments, maturity ranges	1 month	1 month
Maximum | Short-term investments
Schedule of Available-for-sale Securities [Line Items]
Short-term investments, maturity ranges	12 months	12 months

Debt - Narrative (Details)

Debt - Narrative (Details) - USD ($)	Mar. 22, 2017	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016	Mar. 06, 2017	Dec. 31, 2012	Nov. 30, 2012
Debt Instrument [Line Items]
Distribution of remaining loan proceeds	$ 26,600,000
Payment towards debt obligations		$ 1,676,000	$ 1,191,000
Current portion of long-term debt, net		3,502,000		$ 4,939,000
Long-term debt, net		41,306,000		14,921,000
Interest expense recognized related to loan		656,000	740,000
BioPharma-II
Debt Instrument [Line Items]
Interest expense recognized related to loan		700,000	700,000
HealthCare Royalty Partners III, L.P.
Debt Instrument [Line Items]
Remaining loan obligations		45,000,000
Current portion of long-term debt, net		3,533,000
Long-term debt, net		41,467,000
Debt issuance costs		200,000
HealthCare Royalty Partners III, L.P. | Curis Royalty, LLC
Debt Instrument [Line Items]
Loan received					$ 45,000,000
Annual interest rate					9.95%
BioPharma-II | Curis Royalty, LLC
Debt Instrument [Line Items]
Remaining loan obligations					$ 18,400,000
Credit agreement with BioPharma-II
Debt Instrument [Line Items]
Accrued interest on loan amount to Curis Royalty given by BioPharma under credit agreement		100,000		200,000
Credit agreement with BioPharma-II | Curis Royalty, LLC
Debt Instrument [Line Items]
Loan received						$ 30,000,000	$ 30,000,000
Annual interest rate						12.25%	12.25%
Percentage equal to the price of the outstanding principal of the loan that may be prepaid						105.00%
Payment towards debt obligations		2,400,000	1,900,000
Current portion of long-term debt, net				4,900,000
Long-term debt, net				$ 14,900,000
Credit agreement with BioPharma-II | Curis Royalty, LLC | Principal portion
Debt Instrument [Line Items]
Payment towards debt obligations		$ 1,700,000	$ 1,200,000

Debt - Schedule of Principal Pa

Debt - Schedule of Principal Payments (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Less current portion, gross	$ (3,502)	$ (4,939)
Total long-term debt obligations, gross	41,306	$ 14,921
HealthCare Royalty Partners III, L.P.
Debt Instrument [Line Items]
2,017	2,348
2,018	4,325
2,019	5,780
2,020	7,137
2,021	8,599
2,022	10,058
Thereafter	6,753
Total payments	45,000
Less current portion, gross	(3,533)
Total long-term debt obligations, gross	$ 41,467

Accrued Liabilities (Details)

Accrued Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Other Liabilities Disclosure [Abstract]
Accrued compensation	$ 1,052	$ 2,026
Professional fees	158	157
Accrued interest on debt (Note 7)	112	194
Other	251	348
Total	$ 1,573	$ 2,725

Accounting for Stock-Based Co34

Accounting for Stock-Based Compensation - Narrative (Details) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2017USD ($)plan$ / sharesshares	Mar. 31, 2016USD ($)$ / shares
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Number of shareholder-approved, share-based compensation plans | plan	2
Number of options granted (in shares) | shares	5,654,000
Stock option granted, exercise price per share (in dollars per share) | $ / shares	$ 2.52
Weighted average grant-date fair values of stock options (in dollars per share) | $ / shares	$ 2.52	$ 1.07
Unrecognized compensation cost, net of estimated forfeitures	$ 12.5
Unrecognized compensation cost, weighted average period for recognition	2 years 10 months 20 days
Intrinsic values of employee stock options exercised	$ 0.7	$ 0.1
Fair values of vested stock options	1.5	1.5
Non-employee compensation expense, recognized expenses (reversals)		(0.1)
Stock options outstanding
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Compensation expense related to employee and director stock option grants	$ 1.1	$ 0.9
2010 Plan
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Number of options granted (in shares) | shares	4,814,000
Vesting period of options	4 years
2010 Plan | Non-employee directors
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Number of options granted (in shares) | shares	840,000
Vesting period of options	1 year
Stock option granted, exercise price per share (in dollars per share) | $ / shares	$ 2.31
2010 Plan | Tranche one
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Percentage of vested shares which are exercisable under stock option	25.00%
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%

Accounting for Stock-Based Co35

Accounting for Stock-Based Compensation - Key Assumptions (Details)	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Risk-free interest rate	2.10%
Risk-free interest rate, minimum		1.60%
Risk-free interest rate, maximum		1.80%
Volatility, minimum	63.00%	69.00%
Volatility, maximum	64.00%	70.00%
Dividends	0.00%	0.00%
Employees
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Expected life	5 years 6 months	6 years
Officer
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Expected life	5 years 6 months	6 years
Directors
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Expected life	6 years 3 months	7 years

Accounting for Stock-Based Co36

Accounting for Stock-Based Compensation - Summary of Stock Option Activity (Details) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2017USD ($)$ / sharesshares
Number of Shares
Beginning balance (in shares) | shares	13,752,157
Granted (in shares) | shares	5,654,000
Exercised (in shares) | shares	(449,152)
Canceled (in shares) | shares	(258,003)
Ending balance (in shares) | shares	18,699,002
Exercisable at March 31, 2017 (in shares) | shares	7,665,796
Vested and unvested expected to vest (in shares) | shares	17,557,600
Weighted Average Exercise Price per Share
Beginning balance (in dollars per share) | $ / shares	$ 2.30
Granted (in dollars per share) | $ / shares	2.52
Exercised (in dollars per share) | $ / shares	1.42
Canceled (in dollars per share) | $ / shares	3.10
Ending balance (in dollars per share) | $ / shares	2.37
Exercisable at March 31, 2017 (in dollars per share) | $ / shares	2.59
Vested and unvested expected to vest (in dollars per share) | $ / shares	$ 2.38
Weighted Average Remaining Contractual Life
Outstanding, March 31, 2017	7 years 8 months 25 days
Exercisable at March 31, 2017	5 years 7 months
Vested and unvested expected to vest	7 years 7 months 12 days
Aggregate Intrinsic Value
Outstanding, March 31, 2017 | $	$ 10,598
Exercisable at March 31, 2017 | $	4,218
Vested and unvested expected to vest | $	$ 10,020

Accounting for Stock-Based Co37

Accounting for Stock-Based Compensation - Schedule of Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Total stock-based compensation expense	$ 1,103	$ 772
Research and development expenses
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Total stock-based compensation expense	289	122
General and administrative expenses
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Total stock-based compensation expense	$ 814	$ 650

Accumulated Other Comprehensi38

Accumulated Other Comprehensive Income (Loss) - Summary of Changes (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ 29,266
Ending balance	21,477
Accumulated net unrealized investment gain (loss)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(4)	$ 28
Unrealized gain on marketable securities	(2)	32
Amounts reclassified from accumulated other comprehensive income (loss)	0	0
Net current period other comprehensive income	(2)	32
Ending balance	$ (6)	$ 60

Common Stock (Details)

Common Stock (Details) - Cowen - At-the-market sale facility - USD ($)	Jul. 02, 2015	Mar. 31, 2017
Class of Stock [Line Items]
Compensation payable, percentage of gross sales price	3.00%
Shares of common stock sold (in shares)		2,103,981
Net proceeds from sold shares of common stock		$ 6,200,000
Maximum
Class of Stock [Line Items]
Planned proceeds from sale of stock (up to)	$ 30,000,000	$ 30,000,000

Loss Per Common Share (Details)

Loss Per Common Share (Details) - shares	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Stock options outstanding
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities (in shares)	18,699,002	17,481,007