Tobira Therapeutics 10-Q 9 May 16 2016 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2016	May. 02, 2016
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2016
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	Q1
Trading Symbol	TBRA
Entity Registrant Name	Tobira Therapeutics, Inc.
Entity Central Index Key	1,311,596
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		18,815,689

Condensed Balance Sheets

Condensed Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 52,339	$ 62,431
Prepaid expenses and other current assets	1,164	802
Total current assets	53,503	63,233
Property and equipment, net	371	400
Restricted cash	334	334
Other assets	1,618	1,441
Total assets	55,826	65,408
Current liabilities:
Accounts payable	3,769	3,089
Accrued expenses and other liabilities	4,985	4,263
Capital lease obligations	24	23
Deferred rent	54	48
Term loan	1,109
Total current liabilities	9,941	7,423
Capital lease obligations	11	17
Deferred rent	166	184
Term loan	13,970	15,013
Total liabilities	$ 24,088	$ 22,637
Commitments and contingencies (Note 9)
Stockholders’ equity:
Preferred stock, par value of $0.001 per share; 1,000,000 shares authorized and no shares issued and outstanding as of March 31, 2016 and December 31, 2015
Common stock, par value of $0.001 per share; 500,000,000 shares authorized and 18,815,689 shares issued and outstanding as of March 31, 2016 and December 31, 2015	$ 19	$ 19
Additional paid-in capital	207,317	206,129
Accumulated deficit	(175,598)	(163,377)
Total stockholders’ equity	31,738	42,771
Total liabilities and stockholders’ equity	$ 55,826	$ 65,408

Condensed Balance Sheets (Paren

Condensed Balance Sheets (Parenthetical) - $ / shares	Mar. 31, 2016	Dec. 31, 2015
Statement Of Financial Position [Abstract]
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	1,000,000	1,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	500,000,000	500,000,000
Common stock, shares issued	18,815,689	18,815,689
Common stock, shares outstanding	18,815,689	18,815,689

Condensed Statements of Operati

Condensed Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Income Statement [Abstract]
Collaboration revenue	$ 107
Operating expenses:
Research and development	8,679	$ 5,671
General and administrative	3,341	2,152
Total operating expenses	12,020	7,823
Loss from operations	(11,913)	(7,823)
Other income (expense), net:
Interest expense, net	(308)	(1,245)
Change in fair value of preferred stock warrant liabilities		2,036
Net loss and comprehensive loss	$ (12,221)	$ (7,032)
Net loss per share, basic and diluted	$ (0.65)	$ (17.43)
Weighted-average common shares outstanding, basic and diluted	18,815,689	403,539

Condensed Statements of Cash Fl

Condensed Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Operating activities
Net loss	$ (12,221)	$ (7,032)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation	1,188	230
Depreciation and amortization	30	30
Amortization of debt discount	66	237
Amortization of beneficial conversion feature		24
Noncash interest expense on convertible notes		721
Change in fair value of preferred stock warrant liabilities		(2,036)
Change in assets and liabilities:
Prepaid expenses and other assets	(540)	769
Accounts payable and accrued expenses	1,403	1,093
Deferred rent	(12)	(10)
Net cash used in operating activities	(10,086)	(5,974)
Investing activities
Purchase of property and equipment		(22)
Net cash used in investing activities		(22)
Financing activities
Proceeds from convertible notes, related party		13,000
Payments on capital lease obligations	(6)	(5)
Net cash provided by (used in) financing activities	(6)	12,995
Net increase (decrease) in cash and cash equivalents	(10,092)	6,999
Cash and cash equivalents at beginning of period	62,431	6,178
Cash and cash equivalents at end of period	52,339	13,177
Supplemental disclosure of cash flow information
Cash paid for interest	$ 262	262
Noncash activities:
Financing costs in accrued expenses		$ 38

Description of Business

Description of Business	3 Months Ended
	Mar. 31, 2016
Accounting Policies [Abstract]
Description of Business	1. DESCRIPTION OF BUSINESS Tobira Therapeutics, Inc., or Tobira or the Company, is a clinical-stage biopharmaceutical company focused on the development and commercialization of novel therapies to treat liver disease, inflammation, fibrosis and HIV. The Company’s lead product candidate, cenicriviroc, or CVC, is an immunomodulatory and dual inhibitor of CCR2 and CCR5 being evaluated for the treatment of non-alcoholic steatohepatitis, or NASH, primary sclerosing cholangitis, or PSC, and as an adjunctive therapy to standard of care in HIV. The Company’s products also include evogliptin, or EVO, a DPP-4 inhibitor, which the Company plans to develop for NASH in combination with CVC. The Company operates in one reportable segment in the United States of America. The Company, or Tobira, as used in the accompanying notes to the unaudited condensed financial statements, refers to Private Tobira prior to the completion of the Merger and Public Tobira subsequent to the completion of the Merger. See the note “Reverse Merger” in the accompanying notes to the condensed financial statements.

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2016
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Basis of Presentation The accompanying unaudited condensed financial statements were prepared in accordance with generally accepted accounting principles in the United States of America, or GAAP, for interim financial information and instructions to Form 10-Q and Article 10 of Regulation S-X set forth by the Securities and Exchange Commission, or the SEC, for interim reporting. As permitted under these rules, certain footnotes or other financial information normally required by GAAP may be condensed or omitted. These financial statements were prepared on the same basis as the Company’s annual financial statements and, in the opinion of management, reflect all adjustments including normal and recurring adjustments which the Company considers necessary for the fair presentation of financial information. These financial statements do not include all information required under GAAP for a complete set of financial statements. The condensed results of operations and comprehensive loss for the three months ended March 31, 2016 are not necessarily indicative of expected results for the full fiscal year or any other period. The condensed results of operations and comprehensive loss and the condensed statement of cash flows for the three months ended March 31, 2015 were derived from unaudited interim financial statements filed on Form 8-K/A on June 2, 2015. The condensed balance sheet as of December 31, 2015 was derived from the Company’s audited financial statements filed on Form 10-K on March 3, 2016. The accompanying unaudited condensed financial statements and notes should be read in conjunction with the audited financial statements and accompanying notes for the year ended December 31, 2015 included in the Company’s Form 10-K filed on March 3, 2016. There have been no significant and material changes in our critical accounting policies and significant judgments and estimates during the three months ended March 31, 2016, except where described in the Company’s significant accounting policies below. Use of Estimates The preparation of the financial statements in conformity with GAAP requires management to make informed estimates and assumptions that impact the reported amounts of assets, liabilities and expenses and the disclosure of contingent assets and liabilities in the Company’s financial statements and accompanying notes as of the date of the financial statements. The most significant estimates in the Company’s financial statements include stock-based compensation, completeness of clinical trial accruals and income taxes. Management bases its estimates on historical experience and on various other market-specific and relevant assumptions that management believes to be reasonable. Actual results may be materially different from those estimates. Collaboration Revenue Revenue consists of amounts earned from collaboration agreements, as discussed in the note “Collaboration Agreement” in the accompanying notes to the condensed financial statements. The Company may enter into license and collaborative research and development agreements with pharmaceutical and biotechnology partners that may involve multiple deliverables. The Company’s agreements may include one or more of the following elements: upfront license payments, cost reimbursement for the performance of research and development activities, milestone payments, other contingent payments, contract manufacturing service fees, royalties and license fees. Each deliverable in an agreement is evaluated to determine whether it meets the criteria to be accounted for as a separate unit of accounting or whether it should be combined with other deliverables. In order to account for the multiple-element arrangements, the Company identifies the deliverables included within an agreement and evaluates which deliverables represent separate units of accounting. Analyzing an arrangement to identify deliverables requires the use of judgment, and each deliverable may be an obligation to deliver services, a right or license to use an asset, or another performance obligation. The Company recognizes revenue when there is persuasive evidence that an arrangement exists, delivery has occurred or services have been rendered, the price is fixed or determinable and collectability is reasonably assured. Non-refundable upfront fees received for license and collaborative agreements entered into and other payments under collaboration agreements where the Company has continuing performance obligations related to the payments are deferred and recognized over the estimated performance period. Revenue is recognized on a ratable basis, unless the Company determines that another method is more appropriate, through the date at which the Company’s performance obligations are completed. Management makes its best estimate of the period over which the Company expects to fulfill its performance obligations, which may include clinical development activities. Given the uncertainties of research and development collaborations, significant judgment is required to determine the duration of the performance period. The Company recognizes cost reimbursement revenue under collaborative agreements as related research and development costs are incurred, as provided for under the terms of these agreements. Research and Development Expenses Research and development expenses consist primarily of fees paid to contract research organizations and other vendors for clinical, non-clinical and manufacturing services, salaries and related overhead expenses, consultant expenses, costs related to acquiring manufacturing materials and costs related to compliance with regulatory requirements. The Company recognizes research and development expenses as incurred, typically estimated based on an evaluation of the progress to completion of specific tasks using data such as patient enrollment, clinical site activations, manufacturing steps completed, or information provided by vendors on their actual costs incurred. Amounts incurred in connection with collaboration agreements are included in research and development expenses. The Company determines the estimates by reviewing contracts, vendor agreements and purchase orders, and through discussions with internal clinical personnel and external service providers as to the progress or stage of completion of trials or services and the agreed-upon fee to be paid for such services. These estimates are made by the Company as of each balance sheet date based on facts and circumstances known to the Company at that time. If the actual timing of the performance of services or the level of effort varies from the estimate, the Company will adjust the estimate accordingly. Nonrefundable advance payments for goods and services, including CRO services, fees for process development or manufacturing and distribution of clinical supplies that will be used in future research and development activities, are capitalized as prepaid expenses and recognized as expense in the period that the related goods are consumed or services are performed. The Company may pay fees to third parties for clinical, non-clinical and manufacturing services that are based on contractual milestones that may result in uneven payment flows. There may be instances in which payments made to vendors will exceed the level of services provided and result in a prepayment of the research and development expense. Stock-Based Compensation Expense For stock options granted to employees, the Company recognizes compensation expense for all stock-based awards based on the grant date estimated fair value. The value of the portion of the award that is ultimately expected to vest is recognized as expense ratably over the requisite service period. The fair value of stock options is determined using the Black-Scholes option pricing model net of estimated forfeitures. The determination of fair value for stock-based awards on the date of grant using an option pricing model requires management to make certain assumptions regarding subjective variables. Stock-based compensation expense related to stock options granted to non-employees is recognized based on the fair value of the stock options, determined using the Black-Scholes option pricing model, as the options are vested. The awards generally vest over the time period the Company expects to receive services from non-employees. Stock options granted to non-employees are subject to periodic revaluation over their vesting terms. Net Loss Per Share Basic net loss per common share is calculated by dividing the net loss attributable to common stockholders by the weighted-average number of common shares outstanding during the period, without consideration for potentially dilutive securities. Diluted net loss per share is computed by dividing the net loss attributable to common stockholders by the weighted-average number of common shares and potentially dilutive securities outstanding for the period determined using the treasury-stock and if-converted methods. The calculation of diluted loss per share also requires that, to the extent the average market price of the underlying shares for the reporting period exceeds the exercise price of the warrants and the presumed exercise of such securities are dilutive to earnings (loss) per share for the period, adjustments to net income or net loss used in the calculation are required to remove the change in fair value of the warrants for the period. Likewise, adjustments to the denominator are required to reflect the related dilutive shares. For purposes of the diluted net loss per share calculation, convertible preferred stock, convertible notes and accrued interest, stock options and preferred stock warrants are considered to be potentially dilutive securities and are excluded from the calculation of diluted net loss per share because their effect would be anti-dilutive. Therefore, basic and diluted net loss per share was the same for the periods presented due to the Company’s net loss position. The following table sets forth the outstanding potentially dilutive securities, as adjusted retroactively to reflect the exchange for Regado shares in connection with the Merger which have been excluded in the calculation of diluted net loss per share because including such would be anti-dilutive (in common stock equivalent shares): Three Months Ended March 31, 2016 2015 Common stock options 3,284,327 1,110,744 Warrants to purchase common stock 64,657 — Warrants to purchase preferred stock — 901,987 Convertible preferred stock — 5,644,539 Convertible notes — 4,722,064 Total 3,348,984 12,379,334 Recent Accounting Pronouncements In March 2016, the Financial Accounting Standards Board, or the FASB, issued Accounting Standards Update, or ASU, No. 2016-09, Compensation — Stock Compensation (Topic 718) In February 2016, the FASB issued ASU, No. 2016-02, Leases (Topic 842) In November 2015, the FASB issued ASU, No. 2015-17, Income Taxes (Topic 740): Balance Sheet Classification of Deferred Taxes In April 2015, the FASB issued ASU No. 2015-03, Interest — Imputation of Interest (Subtopic 835-30): Simplifying the Presentation of Debt Issuance Costs In August 2014, the FASB issued ASU No. 2014-15, Presentation of Financial Statements — Going Concern (Subtopic 205-40): Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers (Topic 606) Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date In March 2016, the FASB issued ASU, No. 2016-08, Revenue from Contracts with Customers (Topic 606) Revenue from Contracts with Customers (Topic 606).

Reverse Merger

Reverse Merger	3 Months Ended
	Mar. 31, 2016
Business Combinations [Abstract]
Reverse Merger	3. REVERSE MERGER Pro Forma Results in connection with Merger The Company completed its Merger with Regado on May 4, 2015. Based on terms of the Merger Agreement dated January 14, 2015 and amended on January 23, 2015, Private Tobira was deemed the acquiring company for accounting purposes, and the transaction was accounted for as a reverse acquisition under the acquisition method of accounting for business combinations in accordance with GAAP. Accordingly, the assets and liabilities of Regado were recorded at estimated fair value as of the Merger closing date. Operating expenses attributable to the former Regado business activities after the Merger were $0.4 million for the three months ended March 31, 2016. The unaudited financial information in the following table summarizes the combined results of operations of the Company and Regado, on a pro forma basis (in thousands, except per share data): Three Months Ended March 31, 2016 2015 Net loss attributable to stockholders $ (12,221 ) $ (13,518 ) Net loss attributable to preferred stockholders $ — $ (200 ) Net loss attributable to common stockholders, basic and diluted $ (12,221 ) $ (13,318 ) Net loss per share, basic and diluted $ (0.65 ) $ (0.90 ) The above unaudited pro forma information was determined based on historical GAAP results of Tobira and Regado. The unaudited pro forma combined results are not necessarily indicative of what the Company’s combined results of operations would have been if the acquisition was completed on January 1, 2015, which represents the first day applicable to present financial information on a pro forma basis. The unaudited pro forma combined net loss includes pro forma adjustments primarily relating to the following non-recurring items directly attributable to the business combination: · Elimination of transaction costs of $0 and $2.6 million for the three months ended March 31, 2016 and 2015, respectively; · Elimination of interest expense of $0 and $0.9 million for the three months ended March 31, 2016 and 2015, respectively, related to the conversion of Private Tobira’s convertible notes in connection with the Merger; and · Elimination of the change in fair value of preferred stock warrant liabilities of $0 and $2.0 million of income for the three months ended March 31, 2016 and 2015, respectively, to reflect 1) the net exercise and cancellation of warrants issued in connection with the convertible notes payable and 2) the conversion of the Oxford Finance LLC, Square 1, and Comerica warrants from warrants on preferred stock to warrants on common stock eliminating the terms that caused the preferred stock warrants to be classified as a liability.

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2016
Fair Value Disclosures [Abstract]
Fair Value Measurements	4 . FAIR VALUE MEASUREMENTS The following tables and disclosure present information about the Company’s financial assets measured at fair value on a recurring basis as of March 31, 2016 and December 31, 2015 and indicate the fair value hierarchy of the valuation techniques utilized by the Company to determine such fair value (in thousands): March 31, 2016 Level 1 Level 2 Level 3 Total Assets Money market funds $ 50,443 $ — $ — $ 50,443 Total $ 50,443 $ — $ — $ 50,443 December 31, 2015 Level 1 Level 2 Level 3 Total Assets Money market funds $ 60,743 $ — $ — $ 60,743 Total $ 60,743 $ — $ — $ 60,743 The carrying amounts of the Company’s financial instruments, including cash, restricted cash, accounts receivable, deposits, accounts payable, and accrued expenses and other liabilities, approximate fair value due to their short maturities. The Company’s lease obligations and term loan have fair values that approximate their carrying value based on prevailing borrowing rates available to the Company for instruments with similar terms. None of the Company’s non-financial assets or liabilities is recorded at fair value on a non-recurring basis for the periods presented. There were no transfers between levels within the fair value hierarchy during the periods presented. The following table provides a reconciliation of liabilities measured at fair value using Level 3 significant unobservable inputs (in thousands) for the three months ended March 31, 2016 and the year ended December 31, 2015: March 31, 2016 December 31, 2015 Balance, beginning of period $ — $ 2,460 Reclassification of preferred stock warrant liability to additional paid-in capital upon conversion to common stock — (521 ) Change in fair value of preferred stock warrant liabilities (1) — (1,939 ) Balance, end of period $ — $ — (1) Changes in fair value of the preferred stock warrant liabilities were recorded in other income (expense), net on the accompanying Statement of Operations and Comprehensive Loss.

Restricted Cash

Restricted Cash	3 Months Ended
	Mar. 31, 2016
Cash And Cash Equivalents [Abstract]
Restricted Cash	5. RESTRICTED CASH The Company held restricted cash of $0.3 million as of March 31, 2016 and December 31, 2015 consisting of a cash secured letter of credit required by the landlord associated with the May 2014 headquarters lease.

Accrued Expenses and Other Liab

Accrued Expenses and Other Liabilities	3 Months Ended
	Mar. 31, 2016
Payables And Accruals [Abstract]
Accrued Expenses and Other Liabilities	6. ACCRUED EXPENSES AND OTHER LIABILITIES Accrued expenses and other liabilities consist of the following (in thousands): March 31, 2016 December 31, 2015 Clinical trial expenses $ 2,769 $ 2,082 Research and development 962 538 Compensation expense 567 1,182 Professional services and other expenses 687 461 Total accrued expenses and other liabilities $ 4,985 $ 4,263

Debt and Warrants

Debt and Warrants	3 Months Ended
	Mar. 31, 2016
Debt Disclosure [Abstract]
Debt and Warrants	7 . DEBT AND WARRANTS Oxford Finance Term Loan On June 30, 2014, and as amended on May 5, 2015 to address the Merger, and as amended on August 10, 2015, the Company entered into an aggregate $15.0 million, five year term loan with Oxford Finance LLC, or the Oxford Loan. The Oxford Loan bears interest at a fixed rate of 6.954% per annum with interest only payments through December 31, 2016 followed by 30 equal monthly payments of principal and interest until maturity at June 1, 2019. At the time of final payment, the Company is required to pay an exit fee of approximately 5.0% of the original principal balance of the Oxford Loan, which the Company recorded as a liability and debt discount at the origination of the term loan. In addition, the Company incurred loan origination fees and debt issuance costs of $0.2 million which are recorded as a debt discount. In connection with the Oxford Loan, the Company granted a security interest in all of its assets, except intellectual property, provided that a judicial authority could require the Company’s intellectual property to be part of the collateral package to the extent necessary to satisfy repayment if the Company’s other secured assets are insufficient. The Oxford Loan restricts the Company from issuing dividends and contains customary affirmative and negative covenants. As of March 31, 2016, the Company was in compliance with all loan covenants. The Company is permitted to make voluntary prepayments of the Oxford Loan with a prepayment fee, calculated as of the loan origination date, equal to (i) 3.0% of the loan prepaid during the first 12 months, (ii) 2.0% of the loan prepaid in months 13-24 and (iii) 1.0% of the loan thereafter. The Company is required to make mandatory prepayments of the outstanding loan upon the acceleration by the lenders following the occurrence of an event of default, along with a payment of the final payment, the prepayment fee and any other obligations that are due and payable at the time of prepayment. The Company evaluated the Oxford Loan in accordance with accounting guidance for derivatives and determined there was de minimis value to the identified derivative features at issuance and at subsequent reporting periods through March 31, 2016. The Company accounts for the debt discount utilizing the effective interest method. The Company recorded interest expense and amortization of the debt discount of $0.3 million and $0.3 million for the three months ended March 31, 2016 and 2015, respectively. Long-term debt and unamortized discount balances are as follows (in thousands): March 31, 2016 December 31, 2015 Face value of term loan $ 15,000 $ 15,000 Exit fee 755 755 Unamortized debt discount associated with exit fee, debt issuance costs, warrants and loan origination fees (676 ) (742 ) Term loan, net $ 15,079 $ 15,013 As of March 31, 2016, future minimum payments under the Oxford Loan were as follows (in thousands): Year ending December 31, 2016 (remaining nine months) $ 782 2017 6,554 2018 6,554 2019 4,031 Total future minimum payments 17,921 Less: unamortized interest (2,166 ) Less: exit fee (755 ) Present value of loan payments $ 15,000 Warrants The Company had the following shares of common stock warrants outstanding as of March 31, 2016: Shares Outstanding as of Per Share Exercise March 31, Issuance Date Expiration Date Price 2016 November 2011 November 2018 $ 10.14 11,835 May 2013 May 2023 $ 108.18 1,039 June 2014 June 2021 $ 10.14 51,783 64,657

Stock-Based Compensation Expens

Stock-Based Compensation Expense	3 Months Ended
	Mar. 31, 2016
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-Based Compensation Expense	8 . STOCK-BASED COMPENSATION EXPENSE The following table summarizes stock option activity during the three months ended March 31, 2016: Number of Options Weighted- Average Exercise Price Per Share Weighted- Average Remaining Contractual Life (in Years) Weighted- Average Grant Date Fair Value Outstanding as of December 31, 2015 2,369,847 $ 13.99 8.28 Granted 945,480 $ 7.91 $ 5.88 Exercised — $ — Canceled (31,000 ) $ 13.46 Outstanding as of March 31, 2016 3,284,327 $ 12.23 8.52 Vested and expected to vest as of March 31, 2016 3,183,159 $ 12.31 8.24 Vested and exercisable as of March 31, 2016 1,260,974 $ 16.35 7.39 As of March 31, 2016 and December 31, 2015, the total intrinsic value of vested and exercisable options was $2.5 million and $3.8 million, respectively. Stock-based compensation expense related to options granted was recorded as follows (in thousands): Three Months Ended March 31, 2016 2015 Research and development $ 312 $ 33 General and administrative 876 197 Total $ 1,188 $ 230

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2016
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	9 . COMMITMENTS AND CONTINGENCIES Legal Proceedings On February 2, 2015, a purported stockholder of Regado filed a putative class-action lawsuit (captioned Maiman v. Regado Biosciences, Inc. Gilboa v. Regado Biosciences, Inc. In re Regado Biosciences, Inc. Stockholder Litigation

Collaboration Agreement

Collaboration Agreement	3 Months Ended
	Mar. 31, 2016
License Agreement [Abstract]
Collaboration Agreement	1 0 . COLLABORATION AGREEMENT Novartis AG On February 17, 2016, the Company entered into an Agreement for Supply of Materials and Terms of Materials Transfer with Novartis AG, or the Novartis Collaboration. Under the terms of this agreement, Novartis AG, or Novartis, will provide investigational materials to the Company to be studied in combination with the Company’s CVC in preclinical studies. The Company is responsible for the conduct of the study with associated expenses to be reimbursed by Novartis, as incurred. The Company recognized collaboration revenue of $0.1 million during the three months ended March 31, 2016 and recorded a receivable included in prepaid expenses and other current assets of $0.1 million as of March 31, 2016 in the accompanying condensed financial statements.

Subsequent Events

Subsequent Events	3 Months Ended
	Mar. 31, 2016
Subsequent Events [Abstract]
Subsequent Events	11. SUBSEQUENT EVENT On April 11, 2016, the Company entered into two separate license agreements with Dong-A ST Co., Ltd, or Dong-A, pursuant to which (a) the Company obtained an exclusive license in the United States, Canada, European Union states, Switzerland and Australia, or the Territory, for the development and commercialization of EVO for all therapeutic indications, or the Evogliptin License Agreement and (b) Dong-A received an exclusive license to develop and market the Company’s CVC for all therapeutic indications in the Republic of Korea, or the CVC License Agreement, and, together with the Evogliptin License Agreement, the License Agreements. Pursuant to the Evogliptin License Agreement, the Company agreed to pay to Dong-A an upfront cash payment of $1.5 million, and may be required to pay up to $25 million to Dong-A linked to the achievement of certain development and regulatory milestones for the first therapeutic indication and up to $10 million for each additional therapeutic indications in the United States and Europe. Dong-A is also eligible to receive up to an additional $35 million based upon the Company’s achievement of certain commercial milestones. Further, once a licensed product is approved, the Company will be required to make tiered royalty payments in the high single to low double-digits to Dong-A based on net sales of such licensed product in the Territory. Dong-A will be the exclusive supplier of EVO for the Company’s clinical studies and commercial distribution. Pursuant to the CVC License Agreement, Tobira will receive an upfront cash payment of $0.5 million from Dong-A and is eligible to receive up to an additional $2.5 million in payments linked to the achievement of milestones similar to those in the Evogliptin License Agreement for the first therapeutic indication and $0.5 million for each additional therapeutic indication in the Republic of Korea. Further, once a licensed product is approved, Dong-A will be required to make tiered double digit royalty payments to the Company based on net sales of such licensed product in the Republic of Korea.

Summary of Significant Accoun17

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2016
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited condensed financial statements were prepared in accordance with generally accepted accounting principles in the United States of America, or GAAP, for interim financial information and instructions to Form 10-Q and Article 10 of Regulation S-X set forth by the Securities and Exchange Commission, or the SEC, for interim reporting. As permitted under these rules, certain footnotes or other financial information normally required by GAAP may be condensed or omitted. These financial statements were prepared on the same basis as the Company’s annual financial statements and, in the opinion of management, reflect all adjustments including normal and recurring adjustments which the Company considers necessary for the fair presentation of financial information. These financial statements do not include all information required under GAAP for a complete set of financial statements. The condensed results of operations and comprehensive loss for the three months ended March 31, 2016 are not necessarily indicative of expected results for the full fiscal year or any other period. The condensed results of operations and comprehensive loss and the condensed statement of cash flows for the three months ended March 31, 2015 were derived from unaudited interim financial statements filed on Form 8-K/A on June 2, 2015. The condensed balance sheet as of December 31, 2015 was derived from the Company’s audited financial statements filed on Form 10-K on March 3, 2016. The accompanying unaudited condensed financial statements and notes should be read in conjunction with the audited financial statements and accompanying notes for the year ended December 31, 2015 included in the Company’s Form 10-K filed on March 3, 2016. There have been no significant and material changes in our critical accounting policies and significant judgments and estimates during the three months ended March 31, 2016, except where described in the Company’s significant accounting policies below.
Use of Estimates	Use of Estimates The preparation of the financial statements in conformity with GAAP requires management to make informed estimates and assumptions that impact the reported amounts of assets, liabilities and expenses and the disclosure of contingent assets and liabilities in the Company’s financial statements and accompanying notes as of the date of the financial statements. The most significant estimates in the Company’s financial statements include stock-based compensation, completeness of clinical trial accruals and income taxes. Management bases its estimates on historical experience and on various other market-specific and relevant assumptions that management believes to be reasonable. Actual results may be materially different from those estimates.
Collaboration Revenue	Collaboration Revenue Revenue consists of amounts earned from collaboration agreements, as discussed in the note “Collaboration Agreement” in the accompanying notes to the condensed financial statements. The Company may enter into license and collaborative research and development agreements with pharmaceutical and biotechnology partners that may involve multiple deliverables. The Company’s agreements may include one or more of the following elements: upfront license payments, cost reimbursement for the performance of research and development activities, milestone payments, other contingent payments, contract manufacturing service fees, royalties and license fees. Each deliverable in an agreement is evaluated to determine whether it meets the criteria to be accounted for as a separate unit of accounting or whether it should be combined with other deliverables. In order to account for the multiple-element arrangements, the Company identifies the deliverables included within an agreement and evaluates which deliverables represent separate units of accounting. Analyzing an arrangement to identify deliverables requires the use of judgment, and each deliverable may be an obligation to deliver services, a right or license to use an asset, or another performance obligation. The Company recognizes revenue when there is persuasive evidence that an arrangement exists, delivery has occurred or services have been rendered, the price is fixed or determinable and collectability is reasonably assured. Non-refundable upfront fees received for license and collaborative agreements entered into and other payments under collaboration agreements where the Company has continuing performance obligations related to the payments are deferred and recognized over the estimated performance period. Revenue is recognized on a ratable basis, unless the Company determines that another method is more appropriate, through the date at which the Company’s performance obligations are completed. Management makes its best estimate of the period over which the Company expects to fulfill its performance obligations, which may include clinical development activities. Given the uncertainties of research and development collaborations, significant judgment is required to determine the duration of the performance period. The Company recognizes cost reimbursement revenue under collaborative agreements as related research and development costs are incurred, as provided for under the terms of these agreements.
Research and Development Expenses	Research and Development Expenses Research and development expenses consist primarily of fees paid to contract research organizations and other vendors for clinical, non-clinical and manufacturing services, salaries and related overhead expenses, consultant expenses, costs related to acquiring manufacturing materials and costs related to compliance with regulatory requirements. The Company recognizes research and development expenses as incurred, typically estimated based on an evaluation of the progress to completion of specific tasks using data such as patient enrollment, clinical site activations, manufacturing steps completed, or information provided by vendors on their actual costs incurred. Amounts incurred in connection with collaboration agreements are included in research and development expenses. The Company determines the estimates by reviewing contracts, vendor agreements and purchase orders, and through discussions with internal clinical personnel and external service providers as to the progress or stage of completion of trials or services and the agreed-upon fee to be paid for such services. These estimates are made by the Company as of each balance sheet date based on facts and circumstances known to the Company at that time. If the actual timing of the performance of services or the level of effort varies from the estimate, the Company will adjust the estimate accordingly. Nonrefundable advance payments for goods and services, including CRO services, fees for process development or manufacturing and distribution of clinical supplies that will be used in future research and development activities, are capitalized as prepaid expenses and recognized as expense in the period that the related goods are consumed or services are performed. The Company may pay fees to third parties for clinical, non-clinical and manufacturing services that are based on contractual milestones that may result in uneven payment flows. There may be instances in which payments made to vendors will exceed the level of services provided and result in a prepayment of the research and development expense.
Stock-Based Compensation Expense	Stock-Based Compensation Expense For stock options granted to employees, the Company recognizes compensation expense for all stock-based awards based on the grant date estimated fair value. The value of the portion of the award that is ultimately expected to vest is recognized as expense ratably over the requisite service period. The fair value of stock options is determined using the Black-Scholes option pricing model net of estimated forfeitures. The determination of fair value for stock-based awards on the date of grant using an option pricing model requires management to make certain assumptions regarding subjective variables. Stock-based compensation expense related to stock options granted to non-employees is recognized based on the fair value of the stock options, determined using the Black-Scholes option pricing model, as the options are vested. The awards generally vest over the time period the Company expects to receive services from non-employees. Stock options granted to non-employees are subject to periodic revaluation over their vesting terms.
Net Loss Per Share	Net Loss Per Share Basic net loss per common share is calculated by dividing the net loss attributable to common stockholders by the weighted-average number of common shares outstanding during the period, without consideration for potentially dilutive securities. Diluted net loss per share is computed by dividing the net loss attributable to common stockholders by the weighted-average number of common shares and potentially dilutive securities outstanding for the period determined using the treasury-stock and if-converted methods. The calculation of diluted loss per share also requires that, to the extent the average market price of the underlying shares for the reporting period exceeds the exercise price of the warrants and the presumed exercise of such securities are dilutive to earnings (loss) per share for the period, adjustments to net income or net loss used in the calculation are required to remove the change in fair value of the warrants for the period. Likewise, adjustments to the denominator are required to reflect the related dilutive shares. For purposes of the diluted net loss per share calculation, convertible preferred stock, convertible notes and accrued interest, stock options and preferred stock warrants are considered to be potentially dilutive securities and are excluded from the calculation of diluted net loss per share because their effect would be anti-dilutive. Therefore, basic and diluted net loss per share was the same for the periods presented due to the Company’s net loss position. The following table sets forth the outstanding potentially dilutive securities, as adjusted retroactively to reflect the exchange for Regado shares in connection with the Merger which have been excluded in the calculation of diluted net loss per share because including such would be anti-dilutive (in common stock equivalent shares): Three Months Ended March 31, 2016 2015 Common stock options 3,284,327 1,110,744 Warrants to purchase common stock 64,657 — Warrants to purchase preferred stock — 901,987 Convertible preferred stock — 5,644,539 Convertible notes — 4,722,064 Total 3,348,984 12,379,334
Recent Accounting Pronouncements	Recent Accounting Pronouncements In March 2016, the Financial Accounting Standards Board, or the FASB, issued Accounting Standards Update, or ASU, No. 2016-09, Compensation — Stock Compensation (Topic 718) In February 2016, the FASB issued ASU, No. 2016-02, Leases (Topic 842) In November 2015, the FASB issued ASU, No. 2015-17, Income Taxes (Topic 740): Balance Sheet Classification of Deferred Taxes In April 2015, the FASB issued ASU No. 2015-03, Interest — Imputation of Interest (Subtopic 835-30): Simplifying the Presentation of Debt Issuance Costs In August 2014, the FASB issued ASU No. 2014-15, Presentation of Financial Statements — Going Concern (Subtopic 205-40): Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers (Topic 606) Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date In March 2016, the FASB issued ASU, No. 2016-08, Revenue from Contracts with Customers (Topic 606) Revenue from Contracts with Customers (Topic 606).

Summary of Significant Accoun18

Summary of Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 31, 2016
Accounting Policies [Abstract]
Schedule of Potentially Dilutive Securities Excluded from Calculation of Diluted Net Loss Per Share	The following table sets forth the outstanding potentially dilutive securities, as adjusted retroactively to reflect the exchange for Regado shares in connection with the Merger which have been excluded in the calculation of diluted net loss per share because including such would be anti-dilutive (in common stock equivalent shares): Three Months Ended March 31, 2016 2015 Common stock options 3,284,327 1,110,744 Warrants to purchase common stock 64,657 — Warrants to purchase preferred stock — 901,987 Convertible preferred stock — 5,644,539 Convertible notes — 4,722,064 Total 3,348,984 12,379,334

Reverse Merger (Tables)

Reverse Merger (Tables)	3 Months Ended
	Mar. 31, 2016
Business Combinations [Abstract]
Summary of Combined Results of Operations of the Company and Regado on a Pro Forma Basis	The unaudited financial information in the following table summarizes the combined results of operations of the Company and Regado, on a pro forma basis (in thousands, except per share data): Three Months Ended March 31, 2016 2015 Net loss attributable to stockholders $ (12,221 ) $ (13,518 ) Net loss attributable to preferred stockholders $ — $ (200 ) Net loss attributable to common stockholders, basic and diluted $ (12,221 ) $ (13,318 ) Net loss per share, basic and diluted $ (0.65 ) $ (0.90 )

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2016
Fair Value Disclosures [Abstract]
Assets Measured at Fair Value on Recurring Basis	The following tables and disclosure present information about the Company’s financial assets measured at fair value on a recurring basis as of March 31, 2016 and December 31, 2015 and indicate the fair value hierarchy of the valuation techniques utilized by the Company to determine such fair value (in thousands): March 31, 2016 Level 1 Level 2 Level 3 Total Assets Money market funds $ 50,443 $ — $ — $ 50,443 Total $ 50,443 $ — $ — $ 50,443 December 31, 2015 Level 1 Level 2 Level 3 Total Assets Money market funds $ 60,743 $ — $ — $ 60,743 Total $ 60,743 $ — $ — $ 60,743
Reconciliation of Liabilities Measured at Fair Value Using Level 3 Significant Unobservable Inputs	The following table provides a reconciliation of liabilities measured at fair value using Level 3 significant unobservable inputs (in thousands) for the three months ended March 31, 2016 and the year ended December 31, 2015: March 31, 2016 December 31, 2015 Balance, beginning of period $ — $ 2,460 Reclassification of preferred stock warrant liability to additional paid-in capital upon conversion to common stock — (521 ) Change in fair value of preferred stock warrant liabilities (1) — (1,939 ) Balance, end of period $ — $ — (1) Changes in fair value of the preferred stock warrant liabilities were recorded in other income (expense), net on the accompanying Statement of Operations and Comprehensive Loss.

Accrued Expenses and Other Li21

Accrued Expenses and Other Liabilities (Tables)	3 Months Ended
	Mar. 31, 2016
Payables And Accruals [Abstract]
Components of Accrued Expenses and Other Liabilities	Accrued expenses and other liabilities consist of the following (in thousands): March 31, 2016 December 31, 2015 Clinical trial expenses $ 2,769 $ 2,082 Research and development 962 538 Compensation expense 567 1,182 Professional services and other expenses 687 461 Total accrued expenses and other liabilities $ 4,985 $ 4,263

Debt and Warrants (Tables)

Debt and Warrants (Tables)	3 Months Ended
	Mar. 31, 2016
Debt Disclosure [Abstract]
Schedule of Long-Term Debt and Unamortized Discount Balances	Long-term debt and unamortized discount balances are as follows (in thousands): March 31, 2016 December 31, 2015 Face value of term loan $ 15,000 $ 15,000 Exit fee 755 755 Unamortized debt discount associated with exit fee, debt issuance costs, warrants and loan origination fees (676 ) (742 ) Term loan, net $ 15,079 $ 15,013
Schedule of Future Minimum Payments under Oxford Term Loan	As of March 31, 2016, future minimum payments under the Oxford Loan were as follows (in thousands): Year ending December 31, 2016 (remaining nine months) $ 782 2017 6,554 2018 6,554 2019 4,031 Total future minimum payments 17,921 Less: unamortized interest (2,166 ) Less: exit fee (755 ) Present value of loan payments $ 15,000
Schedule of Shares of Common Stock Warrants Outstanding	The Company had the following shares of common stock warrants outstanding as of March 31, 2016: Shares Outstanding as of Per Share Exercise March 31, Issuance Date Expiration Date Price 2016 November 2011 November 2018 $ 10.14 11,835 May 2013 May 2023 $ 108.18 1,039 June 2014 June 2021 $ 10.14 51,783 64,657

Stock-Based Compensation Expe23

Stock-Based Compensation Expense (Tables)	3 Months Ended
	Mar. 31, 2016
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Stock Option Activity	The following table summarizes stock option activity during the three months ended March 31, 2016: Number of Options Weighted- Average Exercise Price Per Share Weighted- Average Remaining Contractual Life (in Years) Weighted- Average Grant Date Fair Value Outstanding as of December 31, 2015 2,369,847 $ 13.99 8.28 Granted 945,480 $ 7.91 $ 5.88 Exercised — $ — Canceled (31,000 ) $ 13.46 Outstanding as of March 31, 2016 3,284,327 $ 12.23 8.52 Vested and expected to vest as of March 31, 2016 3,183,159 $ 12.31 8.24 Vested and exercisable as of March 31, 2016 1,260,974 $ 16.35 7.39
Summary of Stock-Based Compensation Expense	Stock-based compensation expense related to options granted was recorded as follows (in thousands): Three Months Ended March 31, 2016 2015 Research and development $ 312 $ 33 General and administrative 876 197 Total $ 1,188 $ 230

Description of Business - Addit

Description of Business - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2016Segment
Accounting Policies [Abstract]
Number of reportable operating segments	1

Summary of Significant Accoun25

Summary of Significant Accounting Policies - Schedule of Potentially Dilutive Securities Excluded from Calculation of Diluted Net Loss Per Share (Detail) - shares	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total	3,348,984	12,379,334
Convertible Notes [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total		4,722,064
Common Stock Options [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total	3,284,327	1,110,744
Warrants [Member] | Common Stock [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total	64,657
Warrants [Member] | Preferred Stock [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total		901,987
Convertible Preferred Stock [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total		5,644,539

Reverse Merger - Additional Inf

Reverse Merger - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Business Acquisition [Line Items]
Operating expenses	$ 12,020	$ 7,823
Interest expense, net	308	1,245
Change in fair value of preferred stock warrant liabilities		(2,036)	$ (1,939)
Regado [Member]
Business Acquisition [Line Items]
Operating expenses	400
Regado [Member] | Acquisition-related Costs [Member]
Business Acquisition [Line Items]
Transaction costs	0	2,600
Interest expense, net	0	900
Change in fair value of preferred stock warrant liabilities	$ 0	$ (2,000)

Reverse Merger - Summary of Com

Reverse Merger - Summary of Combined Results of Operations of the Company and Regado on a Pro Forma Basis (Detail) - Regado [Member] - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Business Acquisition [Line Items]
Net loss attributable to stockholders	$ (12,221)	$ (13,518)
Net loss attributable to preferred stockholders		(200)
Net loss attributable to common stockholders, basic and diluted	$ (12,221)	$ (13,318)
Net loss per share, basic and diluted	$ (0.65)	$ (0.90)

Fair Value Measurements - Asset

Fair Value Measurements - Assets Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Assets
Total assets at fair value	$ 50,443	$ 60,743
Level 1 [Member]
Assets
Total assets at fair value	50,443	60,743
Money Market Funds [Member]
Assets
Total assets at fair value	50,443	60,743
Money Market Funds [Member] | Level 1 [Member]
Assets
Total assets at fair value	$ 50,443	$ 60,743

Fair Value Measurements - Recon

Fair Value Measurements - Reconciliation of Liabilities Measured at Fair Value Using Level 3 Significant Unobservable Inputs (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2015	Dec. 31, 2015
Fair Value Disclosures [Abstract]
Balance, beginning of period	$ 2,460	$ 2,460
Reclassification of preferred stock warrant liability to additional paid-in capital upon conversion to common stock		(521)
Change in fair value of preferred stock warrant liabilities	$ (2,036)	$ (1,939)

Restricted Cash - Additional In

Restricted Cash - Additional Information (Detail) - USD ($) $ in Millions	Mar. 31, 2016	Dec. 31, 2015
Cash And Cash Equivalents [Abstract]
Restricted cash	$ 0.3	$ 0.3

Accrued Expenses and Other Li31

Accrued Expenses and Other Liabilities - Components of Accrued Expenses and Other Liabilities (Detail) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Payables And Accruals [Abstract]
Clinical trial expenses	$ 2,769	$ 2,082
Research and development	962	538
Compensation expense	567	1,182
Professional services and other expenses	687	461
Total accrued expenses and other liabilities	$ 4,985	$ 4,263

Debt and Warrants - Additional

Debt and Warrants - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Jun. 30, 2014	Dec. 31, 2015
Debt Instrument [Line Items]
Amortization of debt discount	$ 66	$ 237
Oxford Finance Term Loan [Member]
Debt Instrument [Line Items]
Convertible debt, principal amount	$ 15,000		$ 15,000	$ 15,000
Debt instrument term			5 years
Interest rate			6.954%
Maturity date			Jun. 1, 2019
Exit fee percentage			5.00%
Loan origination fees and debt issuance costs			$ 200
Debt instrument prepayment description	The Company is permitted to make voluntary prepayments of the Oxford Loan with a prepayment fee, calculated as of the loan origination date, equal to (i) 3.0% of the loan prepaid during the first 12 months, (ii) 2.0% of the loan prepaid in months 13-24 and (iii) 1.0% of the loan thereafter.
Amortization of debt discount	$ 300	$ 300
Oxford Finance Term Loan [Member] | Loan Prepaid During First 12 Months [Member]
Debt Instrument [Line Items]
Debt instrument prepayment fee percentage	3.00%
Oxford Finance Term Loan [Member] | Loan Prepaid During 13 to 24 Months [Member]
Debt Instrument [Line Items]
Debt instrument prepayment fee percentage	2.00%
Oxford Finance Term Loan [Member] | Loan Prepaid After 24 Months [Member]
Debt Instrument [Line Items]
Debt instrument prepayment fee percentage	1.00%

Debt and Warrants - Schedule of

Debt and Warrants - Schedule of Long-Term Debt and Unamortized Discount Balances (Detail) - Oxford Finance Term Loan [Member] - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015	Jun. 30, 2014
Debt Instrument [Line Items]
Face value of term loan	$ 15,000	$ 15,000	$ 15,000
Exit fee	755	755
Unamortized debt discount associated with exit fee, debt issuance costs, warrants and loan origination fees	(676)	(742)
Term loan, net	$ 15,079	$ 15,013

Debt and Warrants - Schedule 34

Debt and Warrants - Schedule of Future Minimum Payments under Oxford Loan (Detail) - Oxford Finance Term Loan [Member] - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015	Jun. 30, 2014
Debt Instrument [Line Items]
2016 (remaining nine months)	$ 782
2,017	6,554
2,018	6,554
2,019	4,031
Total future minimum payments	17,921
Less: unamortized interest	(2,166)
Less: exit fee	(755)	$ (755)
Present value of loan payments	$ 15,000	$ 15,000	$ 15,000

Debt and Warrants - Summary of

Debt and Warrants - Summary of Shares of Common Stock Warrants Outstanding (Detail)	3 Months Ended
	Mar. 31, 2016$ / sharesshares
Class Of Warrant Or Right [Line Items]
Shares Outstanding	64,657
November 2018 [Member]
Class Of Warrant Or Right [Line Items]
Issuance Date	2011-11
Expiration Date	2018-11
Per Share Exercise Price | $ / shares	$ 10.14
Shares Outstanding	11,835
May 2023 [Member]
Class Of Warrant Or Right [Line Items]
Issuance Date	2013-05
Expiration Date	2023-05
Per Share Exercise Price | $ / shares	$ 108.18
Shares Outstanding	1,039
June 2021 [Member]
Class Of Warrant Or Right [Line Items]
Issuance Date	2014-06
Expiration Date	2021-06
Per Share Exercise Price | $ / shares	$ 10.14
Shares Outstanding	51,783

Stock-Based Compensation Expe36

Stock-Based Compensation Expense - Summary of Stock Option Activity (Detail) - $ / shares	3 Months Ended	12 Months Ended
	Mar. 31, 2016	Dec. 31, 2015
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Number of Options, Outstanding, Beginning Balance	2,369,847
Number of Options, Granted	945,480
Number of Options, Canceled	(31,000)
Number of Options, Outstanding, Ending Balance	3,284,327	2,369,847
Number of Options, Vested and expected to vest	3,183,159
Number of Options, Vested and exercisable	1,260,974
Weighted Average Exercise Price Per Share, Outstanding, Beginning Balance	$ 13.99
Weighted Average Exercise Price Per Share, Granted	7.91
Weighted Average Exercise Price Per Share, Canceled	13.46
Weighted Average Exercise Price Per Share, Outstanding, Ending Balance	12.23	$ 13.99
Weighted Average Exercise Price Per Share, Vested and expected to vest	12.31
Weighted Average Exercise Price Per Share, Vested and Exercisable	$ 16.35
Weighted Average Contractual Term, Outstanding	8 years 6 months 7 days	8 years 3 months 11 days
Weighted Average Contractual Term, Vested and Expected to Vest	8 years 2 months 27 days
Weighted Average Contractual Term, Vested and Exercisable	7 years 4 months 21 days
Weighted-average grant date fair value of Stock Options Outstanding, Granted	$ 5.88

Stock-Based Compensation Expe37

Stock-Based Compensation Expense - Additional Information (Detail) - USD ($) $ in Millions	Mar. 31, 2016	Dec. 31, 2015
Share Based Compensation Arrangement By Share Based Payment Award Additional General Disclosures [Abstract]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Intrinsic Value	$ 2.5	$ 3.8

Stock-Based Compensation Expe38

Stock-Based Compensation Expense - Summary of Stock-Based Compensation Expense (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	$ 1,188	$ 230
Research and Development [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	312	33
General and Administrative [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	$ 876	$ 197

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2016USD ($)
Maximum [Member]
Purchase Commitment Excluding Longterm Commitment [Line Items]
Attorney's fees and expenses	$ 300,000

Subsequent Event - Additional I

Subsequent Event - Additional Information (Detail) - Dong A S T Company Limited - Subsequent Event [Member]	Apr. 11, 2016USD ($)License
Subsequent Event [Line Items]
License Agreement Effective Date	Apr. 11, 2016
Number of License Agreement | License	2
Evogliptin License Agreement [Member]
Subsequent Event [Line Items]
Upfront cash payment	$ 1,500,000
Evogliptin License Agreement [Member] | Maximum [Member]
Subsequent Event [Line Items]
Payment upon achievement of development and regulatory milestones	25,000,000
Additional milestone payment for each additional therapeutic indication	10,000,000
Additional payment receivable upon achievement of commercial milestones	35,000,000
CVC License Agreement [Member]
Subsequent Event [Line Items]
Upfront cash payment receivable	500,000
Additional milestone payment for each additional therapeutic indication	500,000
CVC License Agreement [Member] | Maximum [Member]
Subsequent Event [Line Items]
Additional payment receivable upon achievement of milestones	$ 2,500,000

Collaboration Agreement - Addit

Collaboration Agreement - Additional Information (Detail) $ in Thousands	3 Months Ended
	Mar. 31, 2016USD ($)
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Collaboration revenue	$ 107
Novartis AG
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Collaboration revenue	100
Prepaid Expenses and Other Current Assets | Novartis AG
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Receivables	$ 100