Ocera Therapeutics 10-K 14 Mar 17 2016 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Feb. 28, 2017	Jun. 30, 2016
Document and Entity Information [Abstract]
Entity Registrant Name	Ocera Therapeutics, Inc.
Entity Central Index Key	1,274,644
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Document Type	10-K
Document Period End Date	Dec. 31, 2016
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Common Stock, Shares Outstanding		23,600,242
Public Float			$ 35,090
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filer	No
Entity Current Reporting Status	Yes

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 24,611	$ 35,921
Short-term marketable securities	3,749	7,415
Prepaid expenses and other current assets	584	686
Total current assets	28,944	44,022
Property and equipment, net	64	94
Deposits	36	26
Goodwill	595	595
Total assets	29,639	44,737
Current liabilities:
Accounts payable	1,215	701
Accrued liabilities	2,839	3,133
Notes payable, short-term (Note 8)	9,703	0
Total current liabilities	13,757	3,834
Notes payable, long-term (Note 8)	0	9,508
Other liabilities	145	1
Total liabilities	13,902	13,343
Commitments and contingencies (Note 13)
Preferred stock, $0.00001 par value, 5,000,000 shares authorized; no shares issued or outstanding at December 31, 2016 and December 31, 2015.	0	0
Common stock, $0.00001 par value, 100,000,000 shares authorized; 23,600,242 shares issued and outstanding at December 31, 2016 and 20,695,160 shares issued and outstanding at December 31, 2015.	0	0
Additional paid-in capital	174,065	162,832
Accumulated other comprehensive loss	0	(5)
Accumulated deficit	(158,328)	(131,433)
Total stockholders’ equity	15,737	31,394
Total liabilities and stockholders’ equity	$ 29,639	$ 44,737

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2016	Dec. 31, 2015
Statement of Financial Position [Abstract]
Preferred stock, par value (usd per share)	$ 0.00001	$ 0.00001
Preferred stock, shares authorized (shares)	5,000,000	5,000,000
Preferred stock, shares issued (shares)	0	0
Preferred stock, shares outstanding (shares)	0	0
Common stock, par value (usd per share)	$ 0.00001	$ 0.00001
Common stock, shares authorized (shares)	100,000,000	100,000,000
Common stock, shares issued (shares)	23,600,242	20,695,160
Common stock, shares outstanding (shares)	23,600,242	20,695,160

Consolidated Statements of Oper

Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Revenues:
Royalty and licensing revenues	$ 609	$ 133	$ 341
Operating expenses:
Research and development	16,125	15,977	14,945
General and administrative	10,364	10,321	9,910
Amortization of intangibles	0	171	164
Total operating expenses	26,489	26,469	25,019
Other income (expense):
Interest and other income	109	89	66
Interest and other expense	(1,124)	(502)	(12)
Total other income (expense), net	(1,015)	(413)	54
Net loss from continuing operations	(26,895)	(26,749)	(24,624)
Net income from discontinued operations	0	227	1,199
Net loss	$ (26,895)	$ (26,522)	$ (23,425)
Net loss per share:
Net loss per share from continuing operations, basic and diluted (in dollars per share)	$ (1.22)	$ (1.33)	$ (1.41)
Net income (loss) per share from discontinued operations, basic and diluted (usd per share)	0	0.01	0.07
Net loss per share, basic and diluted (in dollars per share)	$ (1.22)	$ (1.32)	$ (1.34)
Weighted average number of shares used to compute net loss per share of common stock, basic and diluted (shares)	21,957,917	20,067,660	17,525,187
Net loss	$ (26,895)	$ (26,522)	$ (23,425)
Unrealized gain (loss) on investments	5	22	(30)
Comprehensive loss	$ (26,890)	$ (26,500)	$ (23,455)

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit
Stockholders' equity, balance at beginning of period at Dec. 31, 2013	$ 45,132	$ 0	$ 126,615	$ 3	$ (81,486)
Stockholders' equity, balance at beginning of period, shares at Dec. 31, 2013		15,300,214
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock, net of issuance cost	23,384		23,384
Issuance of common stock, net of issuance cost, shares		4,200,000
Issuance of common stock upon exercise of stock options, shares		225,871
Issuance of common stock upon exercise of stock options, value	398		398
Issuance of common stock upon cashless exercise of stock options, shares		15,673
Issuance of common stock upon cashless exercise of stock warrants, shares		5,604
Share-based compensation expense	4,686		4,686
Net loss	(23,425)				(23,425)
Other comprehensive income (loss)	(30)			(30)
Stockholders' equity, balance at end of period at Dec. 31, 2014	50,145	$ 0	155,083	(27)	(104,911)
Stockholders' equity, balance at end of period, shares at Dec. 31, 2014		19,747,362
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock, net of issuance cost	$ 3,455		3,455
Issuance of common stock, net of issuance cost, shares		946,497
Issuance of common stock upon exercise of stock options, shares	0
Issuance of common stock warrants in connection with notes payable	$ 317		317
Issuance of common stock upon cashless exercise of stock warrants, shares		1,301
Share-based compensation expense	3,977		3,977
Net loss	(26,522)				(26,522)
Other comprehensive income (loss)	22			22
Stockholders' equity, balance at end of period at Dec. 31, 2015	31,394	$ 0	162,832	(5)	(131,433)
Stockholders' equity, balance at end of period, shares at Dec. 31, 2015		20,695,160
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock, net of issuance cost	$ 7,144		7,144
Issuance of common stock, net of issuance cost, shares		2,865,391
Issuance of common stock upon exercise of stock options, shares	23,938	23,938
Issuance of common stock upon exercise of stock options, value	$ 26		26
Issuance of common stock upon cashless exercise of stock warrants, shares		15,753
Share-based compensation expense	4,063		4,063
Net loss	(26,895)
Other comprehensive income (loss)	5			5
Stockholders' equity, balance at end of period at Dec. 31, 2016	$ 15,737	$ 0	$ 174,065	$ 0	$ (158,328)
Stockholders' equity, balance at end of period, shares at Dec. 31, 2016		23,600,242

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Statement of Cash Flows [Abstract]
Net loss	$ (26,895)	$ (26,522)	$ (23,425)
Operating activities
Net loss	(26,895)	(26,522)	(23,425)
Adjustments to reconcile net loss to net cash used in operating activities:
Net income from discontinued operations	0	(227)	(1,199)
Depreciation	44	42	36
Amortization of intangibles	0	171	164
Stock-based compensation	4,063	3,977	4,686
Accretion of premium on investment securities	41	367	600
Amortization of debt discount	195	77	0
Changes in operating assets and liabilities:
Prepaid expenses and other assets	92	346	(469)
Accounts payable	514	(240)	(341)
Accrued liabilities	(150)	1,168	63
Net cash used in continuing operating activities	(22,096)	(20,841)	(19,885)
Net cash provided by (used in) discontinued operating activities	0	227	(440)
Net cash used in operating activities	(22,096)	(20,614)	(20,325)
Investing activities
Purchases of property and equipment	(14)	(75)	(38)
Purchases of marketable securities	(7,504)	(23,322)	(41,415)
Sale and maturities of marketable securities	11,134	56,602	31,425
Net cash provided by (used in) continuing investing activities	3,616	33,205	(10,028)
Net cash provided by discontinued investing activities	0	0	1,165
Net cash provided by (used in) investing activities	3,616	33,205	(8,863)
Financing activities
Proceeds from the sale of common stock, net of underwriting discounts, commissions and issuance cost	7,144	3,455	23,384
Proceeds from notes payable, net	0	9,748	0
Proceeds from issuance of common stock	26	0	398
Net cash provided by financing activities	7,170	13,203	23,782
Net increase (decrease) in cash and cash equivalents	(11,310)	25,794	(5,406)
Cash and cash equivalents—beginning of period	35,921	10,127	15,533
Cash and cash equivalents, end of year	24,611	35,921	10,127
Supplemental schedule of non-cash investing and financing activities
Cash paid for interest	828	278	0
Fair value of warrants issued in connection with notes payable	0	317	0
Unrealized gain (loss) on investments	$ 5	$ 22	$ (30)

Description of Business and Bas

Description of Business and Basis of Presentation	12 Months Ended
	Dec. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business and Basis of Presentation	Description of Business Ocera Therapeutics, Inc. (the "Company") is a clinical stage biopharmaceutical company targeting acute and clinical orphan liver disease. The Company's initial focus is on the development and commercialization of OCR-002 (ornithine phenylacetate) in both intravenous and oral formulations for the treatment and prevention of hepatic encephalopathy (“HE”). HE is a serious complication of liver cirrhosis, or liver failure, marked by mental changes including confusion, impaired motor skills, disorientation in time and space, and, in its more severe form, stupor, coma and even death. OCR-002 is a novel molecule, ornithine, phenylacetate, which functions as an ammonia scavenger and which the Company believes is the only direct ammonia scavenger currently in clinical development for the treatment and prevention of HE. OCR-002 has been granted orphan drug designation and Fast Track status by the FDA for the treatment of hyperammonemia and resultant HE in patients with acute liver failure and acute-on-chronic liver disease. Orphan drug designation is given to a drug candidate intended to treat a rare disease or condition that affects fewer than 200,000 individuals in the United States. OCR-002 has also been granted orphan drug designation in the European Union for the treatment of acute liver failure. Fast Track designation is available for certain new drug products if they are intended to treat a serious or life-threatening disease or condition and demonstrate the potential to address unmet medical needs for the disease or condition. Fast Track designation does not change the standards for approval but may expedite the development or approval process. On July 15, 2013, Terrapin Acquisition, Inc., a Delaware corporation (“Merger Sub”), a wholly owned subsidiary of Tranzyme, Inc., a Delaware corporation (“Tranzyme”), completed its merger (the “Merger”) with and into Ocera Therapeutics, Inc., a private Delaware corporation (“Private Ocera”). Private Ocera was considered the acquiring company in the Merger for accounting purposes. In connection with the Merger, the combined company changed its name to Ocera Therapeutics, Inc. and the name of Private Ocera was changed to Ocera Subsidiary, Inc. ("Ocera Subsidiary"). The Company has a limited operating history and the sales and income potential of its business and market are unproven. The Company has experienced net losses each year since its inception and, as of December 31, 2016, has an accumulated deficit of $158.3 million . The Company anticipates that it will continue to incur net losses into the foreseeable future and will need to raise additional capital as it continues the development and commercialization of OCR-002. The Company's cash, cash equivalents and marketable securities may not be sufficient to fund its operations beyond early 2018. These factors raise substantial doubt about the Company's ability to continue as a going concern within twelve months following the date of the filing of this Form 10-K. The Company's ability to continue as a going concern and finance operations beyond its current resources will depend heavily on value investors see in the data from previous clinical trials of OCR-002 and favorable results from any future clinical trials of OCR-002 the Company may conduct. The Company plans to raise additional capital through collaboration, licensing or similar arrangements, private and public equity offerings or debt financing, or a combination thereof. Additional financing may not be available when the Company needs it or may not be available on terms that are favorable to the Company. Collaboration, licensing or similar arrangements may require the Company to relinquish valuable rights to its potential products or proprietary technologies. To the extent that the Company raises additional capital through the sale of equity or convertible debt securities, the ownership interest of existing stockholders will be diluted, and the terms may include liquidation or other preferences that adversely affect the rights of existing stockholders. Debt financing, as is the case with the Company's loan facility, results in increased fixed payment obligations and may involve agreements that include covenants limiting or restricting our ability to take specific actions such as incurring debt, making capital expenditures or declaring dividends. Without additional funds, the Company may be forced to delay, scale back or eliminate some of its research and development activities or operations and potentially delay product development of OCR-002. The consolidated financial statements included in this report have been prepared on a going concern basis, which contemplates the realization of assets and the satisfaction of liabilities in the normal course of business. The financial statements do not include any adjustments to reflect the possible future effects on the recoverability and classification of assets or the amounts and classification of liabilities that may result from the outcome of the uncertainty related to our ability to continue as a going concern.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2016
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Basis of Accounting The consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) and the applicable rules and regulations of the Securities and Exchange Commission (“SEC”) and include the accounts of the Company and Ocera Subsidiary, Inc. All significant intercompany balances and transactions have been eliminated in consolidation. All amounts included in these notes to consolidated financial statements are reported in United States dollars, unless otherwise indicated. Use of Estimates The preparation of financial statements in conformity with United States GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Actual results could differ from those estimates. Segment Reporting Operating segments are identified as components of an enterprise about which separate discrete financial information is available for evaluation by the chief operating decision maker in deciding how to allocate resources and in assessing performance. The Company views and manages its business as one operating segment. Cash and Cash Equivalents The Company considers all highly liquid investments with original maturities of three months or less at the date of purchase to be cash equivalents. Cash and cash equivalents include money market funds and various deposit accounts. Concentration of Credit Risk Financial instruments that potentially subject the Company to a significant concentration of credit risk consist primarily of cash and cash equivalents and investments in marketable securities. The Company maintains deposits in federally insured financial institutions in excess of federally insured limits. However, management believes the Company is not exposed to significant credit risk due to the financial position of the depository institutions in which those deposits are held. Additionally, the Company has established guidelines regarding diversification of its investments in marketable securities and their maturities, which are designed to maintain safety and liquidity. Investments in Marketable Securities The Company invests in marketable securities, primarily money market funds, commercial paper, government agency debt securities and United States and foreign corporate debt securities. Investments with original maturities greater than 90 days that mature less than one year from the consolidated balance sheet date are classified as short-term investments. Those investments with a maturity date greater than one year at each balance sheet date are considered to be long-term investments. The Company further classifies investments as short-term or long-term based upon whether such assets are reasonably expected to be realized in cash or sold or consumed during the normal cycle of business. As of December 31, 2016 and 2015 all investments in marketable securities were classified as available-for-sale and are carried at estimated fair value as determined based upon quoted market prices or pricing models for similar securities. Unrealized gains and losses are excluded from earnings and are reported as a component of accumulated comprehensive income (loss). Realized gains and losses and declines in fair value judged to be other than temporary, if any, on investments in marketable securities are included in interest and other income (expense), net. The cost of securities sold is based on the specific-identification method. Interest earned on investments in marketable securities is included in interest and other income. Debt securities are adjusted for amortization of premiums and accretion of discounts and such amortization and accretion are reported as a component of interest and other income. Fair Value Measurements Fair value accounting is applied for all financial assets and liabilities and non-financial assets and liabilities that are recognized or disclosed at fair value in the financial statements on a recurring basis. Fair value is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. Where available, fair value is based on or derived from observable market prices or other observable inputs. Where observable prices or inputs are not available, valuation models are applied. These valuation techniques may involve some level of management estimation and judgment, the degree of which is dependent on the price transparency for the instruments and the instruments’ complexity. The fair value hierarchy prioritizes the inputs to valuation techniques used to measure fair value into three broad levels. All of the Company's cash equivalents and investments are measured using inputs classified at Level 1 or Level 2 within the fair value hierarchy. Level 1 inputs are quoted prices in active markets for identical assets. The Company classifies money market funds as Level 1. Level 2 inputs are based upon quoted prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active and model-based valuation techniques for which all significant inputs are observable in the market or can be corroborated by observable market data for substantially the full term of the assets. The Company’s classifies its commercial paper and corporate debt securities as Level 2. Level 3 inputs are unobservable inputs that are supported by little or no market activity and are significant to the fair value of the assets or liabilities. Where applicable, these models project future cash flows and discount the future amounts to a present value using market-based observable inputs obtained from various third-party data providers, including but not limited to, benchmark yields, interest rate curves, reported trades, broker/dealer quotes and market reference data. Property and Equipment, net Property and equipment, net, are stated at cost less accumulated depreciation. Depreciation is calculated using the straight-line method over the estimated useful lives of the assets. Useful lives generally range from three to five years . Goodwill The Company recorded goodwill upon the Merger. The Company performs an impairment test of goodwill annually and whenever events or changes in circumstances indicate that the carrying amount may not be recoverable. To date, an impairment of goodwill has not been recorded. Revenue Recognition The Company recognizes revenue from licensing agreements for the development and commercialization of products and royalties from the use of our intellectual property. License fees from license agreements are recognized when the amounts are earned. Royalty revenues are recorded based on sales information provided by the Company's licensors. Research and Development Research and development costs are expensed as incurred and consist of salaries and benefits, lab supplies, materials and facility costs, as well as fees paid to other non-employees and entities that conduct certain research and development activities on our behalf. Payments made prior to the receipt of goods or services to be used in research and development are capitalized until the goods are received or services are rendered. Clinical trial costs are a component of research and development expenses. The Company accrues and expenses clinical trial activities performed by third parties based upon actual work completed in accordance with agreements established with clinical research organizations and clinical sites. This process involves identifying services that have been performed and estimating the level of service performed and the associated cost incurred for the service when the Company has not yet been invoiced or otherwise notified of actual cost. The Company's clinical trial accruals are based on estimates of patient enrollment and related costs at clinical investigator sites as well as estimates for the services received and efforts expended pursuant to contracts with vendors including, multiple research institutions and clinical research organizations that conduct and manage clinical trials or provide supporting services on the Company's behalf. The Company accrues expense related to clinical trials based on contracted amounts applied to the level of patient enrollment and/or estimated level of activity completed. If timelines or contracts are modified based upon changes in the clinical trial protocol or scope of work to be performed, the Company modifies the estimates of clinical trial accruals accordingly on a prospective basis. The financial terms of these agreements are subject to negotiation, vary from contract to contract and may result in uneven timing of payments. Payments under some of these contracts depend on factors such as the successful enrollment of patients and the completion of clinical trial milestones. Stock-Based Compensation Employee stock-based compensation is recognized as an expense in the financial statements based on the grant date fair value of the award. For awards that vest based on service conditions, the Company records compensation expense, net of estimated forfeitures, on a straight-line basis over the requisite service period which is generally the vesting period for the related award. For performance-based stock options, the Company evaluates the probability of achieving performance-based goals at each reporting date. The Company begins to recognize the expense when it is deemed probable that the performance-based goal will be met. The Company records equity grants to non-employees as expense at their fair value over the related service period and periodically revalues them at each reporting period over the vesting term. The Company estimates the fair value of stock options using a Black-Scholes-Merton option-pricing model which requires the input of highly subjective assumptions that represent our best estimates of volatility, risk-free interest rate, expected life, and dividend yield. The Company estimates expected volatility based on its own historical volatility supplemented by a review of historical volatilities of industry peers. The Company has, due to insufficient historical data, used the "simplified method," as described in Staff Accounting Bulletin No. 107, "Share-Based Payment," to determine the expected life of stock options granted with a service condition. The risk-free rate assumption was based on United States Treasury instruments whose terms were consistent with the expected term of the stock options. The expected dividend assumption was based on our history and expectation of dividend payouts. The Company accounts for stock-based compensation arrangements with non-employees using a fair value approach. The fair value of these options is measured using the Black-Scholes-Merton option pricing model reflecting the same assumptions as applied to employee options in each of the reported periods, other than the expected life, which is assumed to be the remaining contractual life of the option. The compensation costs of these arrangements are subject to remeasurement over the vesting terms as earned. The Company estimates fair value of stock options with market-based vesting conditions based on Monte Carlo simulation models with assistance from an independent third-party valuation specialist. The Monte Carlo simulation models require the use of highly subjective and complex assumptions which determine the fair value of such awards including price volatility of the underlying stock and derived service periods. The assumptions used in calculating the fair value of stock options with market-based vesting conditions and expected attainment of performance conditions for performance-based stock options represent our best estimates, but these estimates involve inherent uncertainties and the application of management’s judgment. Future expense amounts for any particular period could be affected by changes in the Company's assumptions. Income Taxes The Company accounts for income taxes under the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements. Under this method, the Company determines deferred tax assets and liabilities on the basis of the differences between the financial statement and tax basis of assets and liabilities by using enacted tax rates in effect for the year in which the differences are expected to reverse. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in income in the period that includes the enactment date. The Company recognizes deferred tax assets to the extent that it believes that these assets are more likely than not to be realized. In making such a determination, it considers all available positive and negative evidence, including future reversals of existing taxable temporary differences, projected future taxable income, tax-planning strategies, and results of recent operations. If it is determined that the Company would be able to realize deferred tax assets in the future in excess of their net recorded amount, it would make an adjustment to the deferred tax asset valuation allowance, which would reduce the provision for income taxes. The recognition and measurement of tax benefits requires significant judgment. Judgments concerning the recognition and measurement of tax benefit might change as new information becomes available. The Company records uncertain tax positions on the basis of a two-step process in which (1) it determines whether it is more likely than not that the tax positions will be sustained on the basis of the technical merits of the position and (2) for those tax positions that meet the more-likely-than-not recognition threshold, the Company recognizes the largest amount of tax benefit that is more than 50 percent likely to be realized upon ultimate settlement with the related tax authority. The Company's policy is to recognize interest and penalties related to the underpayment of income taxes as a component of income tax expense or benefit. To date, there have been no interest or penalties charged in relation to the underpayment of income taxes. Recent Accounting Pronouncements Occasionally, new accounting standards are issued or proposed by the Financial Accounting Standards Board (the "FASB"), or other standards-setting bodies that the Company adopts by the effective date specified within the standard. Unless otherwise discussed, standards that do not require adoption until a future date are not expected to have a material impact on the Company's financial statements upon adoption. In August 2014, the FASB issued Accounting Standards Update ("ASU") 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. The standard requires management to assess, at each annual and interim reporting period, whether there are conditions or events that raise substantial doubt about the entity’s ability to continue as a going concern and provide related disclosures in certain circumstances. The Company adopted the guidance as of December 31, 2016 and has included disclosures on this topic in Note 1. In August 2016, the FASB issued ASU 2016-15, Classification of Certain Cash Receipts and Cash Payments, which aims to eliminate diversity in practice in how certain cash receipts and cash payments are presented and classified in the statement of cash flows under Topic 230, Statement of Cash Flows, and other Topics. ASU 2016-15 is effective for annual reporting periods, and interim periods therein, beginning after December 15, 2017. The Company continues to assess the potential impact of this standard, but currently does not expect the adoption of this standard 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 (Topic 718), Compensation - Stock Compensation. The ASU simplifies several aspects of the accounting for share-based payments, including the income tax consequences, changing the threshold to qualify for equity classification to the employees' maximum statutory tax rates, allowing an entity-wide accounting policy election to either estimate the number of awards that are expected to vest or account for forfeitures as they occur, and clarifying the classification on the statement of cash flows for the excess tax benefit and employee taxes paid when an employer withholds shares for tax-withholding purposes. ASU 2016-09 is effective for annual reporting periods beginning after December 15, 2016, and interim periods within that reporting period. The Company will adopt this standard in the first quarter of fiscal year 2017 and is currently evaluating the impact of the guidance on its consolidated financial statements. In February 2016, the FASB issued ASU 2016-02, Leases, to increase transparency and comparability among organizations by requiring recognition of lease assets and lease liabilities on the balance sheet and disclosure of key information about leasing arrangements. The standard will become effective for interim and annual periods beginning after December 15, 2018, with early adoption permitted. The guidance is required to be adopted at the earliest period presented using a modified retrospective approach. The Company is currently evaluating the impact of the adoption of this standard on its consolidated financial statements. In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers. The standard’s core principle is that a reporting entity will recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The standard will become effective for the Company beginning in the first quarter of 2018. Early adoption is permitted in 2017. Entities have the option of using either a full retrospective or a modified retrospective approach to adopt this new guidance. In March and April 2016, the FASB issued ASU 2016-08 Revenue From Contracts With Customers: Principal vs. Agent Considerations and ASU 2016-10 Revenue From Contracts with Customers: Identifying Performance Obligations and Licensing to provide supplemental adoption guidance and clarification to ASU 2014-09. The Company plans to adopt this guidance as of January 1, 2018, using the modified retrospective method and is in the process of evaluating its arrangements where it has licensed or sold intellectual property. The Company has not completed the full assessment and is not able to estimate the anticipated impact to the consolidated financial statements from the application of the new standard. The Company reviewed all other recently issued accounting pronouncements and concluded that they were either not applicable or not expected to have a significant impact to the consolidated financial statements. Additionally, the adoption of accounting pronouncements during 2016 did not have an impact on the Company’s consolidated financial position or results of operations.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2016
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements Financial assets and liabilities are recorded at fair value. The carrying amounts of the Company's cash and cash equivalents, prepaid expenses and other current assets, accounts payable, and accrued liabilities, approximate their fair values due to their short maturities. Short-term and long-term debt are reported at their respective amortized cost on the consolidated balance sheets. The following tables present information about the Company’s financial assets and liabilities measured at fair value on a recurring basis as of December 31, 2016 and 2015 , and indicate the fair value hierarchy of the valuation techniques utilized by the Company to determine such fair value. No transfers between levels have occurred during the periods presented. The Company estimates the fair value of commercial paper and corporate debt securities by taking into consideration valuations obtained from third-party pricing services. The pricing services utilize industry standard valuation models, including both income and market-based approaches, for which all significant inputs are observable, either directly or indirectly, to estimate fair value. These inputs include reported trades of and broker quotes on the same or similar securities; issuer credit spreads; benchmark securities; prepayment or default projections based on historical data; and other observable inputs. Assets and liabilities measured at fair value on a recurring basis as of December 31, 2016 are as follows (in thousands): Total Level 1 Level 2 Level 3 Assets: Money market funds $ 24,593 $ 24,593 $ — $ — Commercial paper 1,498 — 1,498 — Corporate debt securities 2,251 — 2,251 — Total assets $ 28,342 $ 24,593 $ 3,749 $ — The estimated fair value of the Company's notes payable, considering level 2 inputs, approximates their carrying value based upon the borrowing terms and conditions available to the Company at December 31, 2016 . Assets and liabilities measured at fair value on a recurring basis as of December 31, 2015 are as follows (in thousands): Total Level 1 Level 2 Level 3 Assets: Money market funds $ 34,806 $ 34,806 $ — $ — Corporate debt securities 7,415 — 7,415 — Total assets $ 42,221 $ 34,806 $ 7,415 $ — The estimated fair value of the Company's notes payable, considering level 2 inputs, approximates their carrying value based upon the borrowing terms and conditions available to the Company at December 31, 2015 .

Balance Sheet Components

Balance Sheet Components	12 Months Ended
	Dec. 31, 2016
Balance Sheet Components [Abstract]
Balance Sheet Components	Balance Sheet Component Cash Equivalents and Marketable Securities The following table summarizes the Company's cash equivalents and marketable securities as of December 31, 2016 (in thousands): Maturity Amortized Cost Unrealized Gains Unrealized Losses Estimated Fair Value Money market funds (1) n/a $ 24,593 $ — $ — $ 24,593 Commercial paper 1 or less 1,498 — — 1,498 Corporate debt securities 1 or less 2,251 — — 2,251 Total cash equivalents and marketable securities $ 28,342 $ — $ — $ 28,342 (1) Money market funds are classified in cash and cash equivalents on our consolidated balance sheets. The following table summarizes the Company's cash equivalents and marketable securities as of December 31, 2015 (in thousands): Maturity (in Years) Amortized Cost Unrealized Gains Unrealized Losses Estimated Fair Value Money market funds (1) n/a $ 34,806 $ — $ — $ 34,806 Corporate debt securities 1 or less 7,420 — (5 ) 7,415 Total cash equivalents and marketable securities $ 42,226 $ — $ (5 ) $ 42,221 (1) Money market funds are classified in cash and cash equivalents on our consolidated balance sheets. At each reporting date, the Company reviews its investments for impairment to determine if unrealized losses are other-than-temporary. There have been no other-than-temporary impairments on these securities as of December 31, 2016 and 2015 . Realized gains or losses on available-for-sale securities were immaterial for the periods presented. The Company does not intend to and believes it is not more likely than not that it will be required to sell these securities before their maturities. Accrued Liabilities Accrued liabilities consisted of the following (in thousands): December 31, 2016 2015 Clinical trials $ 1,519 $ 1,666 Compensation and related expenses 1,124 993 Professional services 102 319 Interest expense and other 94 155 Total accrued liabilities $ 2,839 $ 3,133

Discontinued Operations

Discontinued Operations	12 Months Ended
	Dec. 31, 2016
Restructuring and Related Activities [Abstract]
Discontinued Operations	Discontinued Operations On September 11, 2013 , the Board of Directors approved a restructuring plan related to the operations of Tranzyme Pharma Inc. (“Tranzyme Pharma”) and its Sherbrooke, Quebec facility, whereby the Company closed the operations of the facility effective November 11, 2013. On December 13, 2013 , the Company entered into a technology transfer and license agreement (the "Technology Transfer and License Agreement") with Genentech, Inc. ("Genentech"), and F. Hoffman-La Roche, Ltd. ("Roche") to sell certain Canadian fixed assets and materials, the MATCH technology and rights to the Genentech and Roche customer agreements and related intellectual property through licensing of patents for $4.0 million . The Company recorded the disposition of these assets held for sale in the first quarter of 2014. The Company concluded that the operations of Tranzyme Pharma and related asset groups sold to Genentech and Roche would be accounted for as discontinued operations as the operations and cash flows of the discontinued component or asset group would be eliminated from ongoing operations of the Company and there would not be significant involvement in the component or asset group after the disposal transaction. In 2014, the Company completed its obligations under the Technology Transfer and License Agreement with Genentech and Roche and recognized a gain on disposal of assets of $1.1 million within discontinued operations. There were no assets and liabilities recorded in discontinued operations as of December 31, 2015 . There was $0.2 million in income recorded in discontinued operations for the twelve-month period ended December 31, 2015 that relates to certain foreign research credits received by Tranzyme Pharma in 2015 prior to its dissolution on December 14, 2015 . Upon classification as held for disposal and discontinued operations, the assets and liabilities of Tranzyme Pharma and related asset groups were evaluated for impairment at the lower of carrying amount or fair value less disposal costs, no impairment loss was recorded.

License Agreements and Acquired

License Agreements and Acquired Development and Commericialization Rights	12 Months Ended
	Dec. 31, 2016
Strategic Collaboration and License Agreements [Abstract]
License Agreements and Acquired Development and Commercialization Rights	License Agreements and Acquired Development and Commercialization Rights UCL Business PLC In December 2008, the Company licensed rights to OCR-002 from UCL Business PLC, an entity affiliated with the University College London (“UCL”), for the exclusive worldwide rights to develop and commercialize OCR-002 and related technologies for any use. The agreement was amended in July 2011, February 2013 and July 2015. As consideration for the license, the Company paid an up-front fee of $1.0 million . The Company may be required to make future milestone payments to UCL totaling up to $20.0 million upon the achievement of various milestones related to clinical and regulatory events for OCR-002. The Company may also be required to pay milestone payments totaling up to $35.0 million upon the achievement of various milestones related to future net sales of OCR-002. The Company is also obligated to pay tiered royalties in the low to mid-single digits on future net sales of the licensed product candidate. Open Biosystems, Inc. In October 2005, Tranzyme entered into a license and marketing agreement whereby Open Biosystems, Inc. acquired a worldwide royalty-bearing license to certain intellectual property unrelated to Tranzyme's lead product candidates prior to the Merger and its MATCH drug discovery technology, as specified in the agreement. The Company earns royalties on annual net sales at rates that vary by licensed product category as defined in the agreement through 2017 or until the expiration date of the last-to-expire licensed patent or twelve years, whichever occurs last. Royalty revenue recognized from the licensing agreement was $0.5 million , $ 0.1 million , and $0.1 million for the years ended December 31, 2016 , 2015 and 2014 , respectively. During the year ended December 31, 2016 , the Company assigned its rights to all the intellectual property acquired in the Merger with Tranzyme to GE Healthcare Dharmacon, Inc. (“GE”), formerly known as Open Biosystems, Inc. In connection with the assignment, the Company’s existing license and marketing agreement with GE terminated and all future royalty payments payable from GE to the Company ceased. In consideration for the assignment, the Company received a one-time payment of $0.5 from GE included in the royalty revenue earned for the year ended December 31, 2016 as presented above. Lyric Pharmaceuticals, Inc. In September 2014, the Company entered into an asset license and purchase agreement for the sale and license of ulimorelin (the "Lyric Agreement"), the former lead compound of Tranzyme to Lyric Pharmaceuticals, Inc. (“Lyric”). Per the terms of the agreement, the Company received an up-front nonrefundable payment of $0.2 million for the transfer of intellectual property and materials associated with the compound and the licensing of associated patents with no further ongoing obligations to be performed by the Company. In addition, Lyric is solely responsible for the pre-clinical and clinical development of all products arising from the further development of the compound. During the year ended December 31, 2016 , Lyric achieved a milestone under the Lyric Agreement, and accordingly, the Company recorded $0.1 million in related milestone revenue in 2016. If successful, the Company could receive future consideration as a percentage of the proceeds received by Lyric upon its sale or license to a third party, and under certain conditions, clinical and regulatory milestones totaling up to $25.0 million plus royalty payments from potential product sales generated.

Net Loss Per Share

Net Loss Per Share	12 Months Ended
	Dec. 31, 2016
Earnings Per Share [Abstract]
Net Loss Per Share	Net Loss Per Share Basic and diluted net loss per share is calculated by dividing the net loss by the weighted average number of common shares outstanding during the period. Common stock equivalents are only included when their effect is dilutive. Potentially dilutive securities which include warrants and outstanding stock options have been excluded from the computation of diluted net loss per share as the effect of their inclusion would be anti-dilutive. For all periods presented, diluted and basic net loss per share were identical due to the Company’s net loss position. The Company has utilized the control number concept in the computation of diluted earnings per share to determine whether potential common stock instruments are dilutive. The control number used is loss from continuing operations. The control number concept requires that the same number of potentially dilutive securities applied in computing diluted earnings per share from continuing operations be applied to all other categories of income or loss, regardless of their anti-dilutive effect on such categories. Therefore, no dilutive effect has been recognized in the calculation of income from discontinued operations per share. The following table presents the computation of net loss per share (in thousands, except share and per share data): Years Ended December 31, 2016 2015 2014 Numerator Net loss from continuing operations $ (26,895 ) $ (26,749 ) $ (24,624 ) Net income from discontinued operations — 227 1,199 Net loss $ (26,895 ) $ (26,522 ) $ (23,425 ) Denominator Weighted average common shares outstanding used to compute net loss per share, basic and diluted 21,957,917 20,067,660 17,525,187 Net loss per share of common stock, basic and diluted: Net loss per share from continuing operations $ (1.22 ) $ (1.33 ) $ (1.41 ) Net income per share from discontinued operations — 0.01 0.07 Net loss per share $ (1.22 ) $ (1.32 ) $ (1.34 ) The following common stock equivalents were excluded from the computation of diluted net loss per share for the periods presented because their effect would be antidilutive. Years Ended December 31, 2016 2015 2014 Common stock warrants 1,003,984 1,026,249 932,535 Common stock options outstanding 3,928,570 2,429,511 2,086,602 Total potentially dilutive securities 4,932,554 3,455,760 3,019,137

Debt

Debt	12 Months Ended
	Dec. 31, 2016
Debt Disclosure [Abstract]
Debt	Debt Notes Payable On July 30, 2015, the Company and Ocera Subsidiary, Inc., entered into a loan and security agreement (the “Loan Agreement”) with Oxford Finance LLC (“Oxford”) and Silicon Valley Bank (“SVB”) (collectively, the “Lenders”). The Loan Agreement provides for up to $20.0 million in new term loans (the “Term Loan Facility”), $10.0 million of which was funded on July 30, 2015. The remaining $10.0 million was not drawn and expired at December 31, 2016 due to non-achievement of certain financial and clinical milestones. The annual interest rate for the $10.0 million funding is 8.275% . Loan payments are interest-only until February 1, 2017, followed by 30 equal monthly payments of principal and interest through the scheduled maturity date of August 1, 2019. In addition, a final payment equal to 3% of the aggregate amount drawn will be due at maturity or on earlier repayment. If the Company prepays all or a portion of the loans, a prepayment fee of between 1% and 3% of the principal amount prepaid will also be due depending on the timing of the prepayment. The Company received net proceeds of $9.7 million after fees and expenses. These fees and expenses are being accounted for as a debt discount and classified within notes payable on the Company’s balance sheet. Related legal and consulting fees of $0.3 million are presented in the balance sheet as a direct deduction from the carrying amount of notes payable, consistent with debt discounts. Debt discounts, issuance costs and the final payment are being amortized or accreted as interest expense over the term of the loan using the effective interest method. In connection with the Loan Agreement, the Company agreed to issue to the Lenders warrants to purchase shares of common stock equal to 4% of the amount loaned, divided by the exercise price, which was the average closing price of the common stock for the 10 trading days prior to funding. Accordingly, in connection with the initial funding, the Company issued the Lenders warrants to purchase an aggregate of 97,680 shares at an exercise price of $4.10 per share. The Company recorded $0.3 million for the relative value of the warrants as a debt discount within notes payable and an increase to additional paid-in capital on the Company’s balance sheet. The debt discount is being amortized as interest expense over the term of the loan using the effective interest method. The fair value of the warrants issued was approximately $0.3 million and was estimated using a Black-Scholes-Merton valuation model on a non-recurring basis with the following assumptions: fair value of common stock at issuance of $3.84 ; risk-free interest rate of 2.28% based upon observed risk-free interest rates appropriate for the expected term of the warrants; expected volatility of 87% based on the average historical volatilities of a peer group of publicly-traded companies within the Company’s industry; expected term of 10 years , which is the contractual life of the warrants; and a dividend yield of 0% . The allocation of proceeds to the warrants in a relative-fair-value allocation with the related notes payable was also $0.3 million . The Term Loan Facility is secured by substantially all of the Company's assets and the assets of Ocera Subsidiary, Inc., except that the collateral does not include any intellectual property held by the Company or Ocera Subsidiary, Inc. However, pursuant to the terms of a negative pledge arrangement, the Company has agreed not to encumber any of the intellectual property of the Company or its subsidiaries. The Loan Agreement contains customary representations, warranties and covenants by the Company, which limit the Company's ability to convey, sell, lease, transfer, assign or otherwise dispose of certain of our assets; engage in any business other than the businesses the Company currently engages in or reasonably related thereto; liquidate or dissolve; make certain management changes; undergo certain change of control events; create, incur, assume, or be liable with respect to certain indebtedness; grant certain liens; pay dividends and make certain other restricted payments; make certain investments; enter into any material transactions with any affiliates, with certain exceptions; make payments on any subordinated debt; and permit certain of the Company's subsidiaries to maintain, own or otherwise hold any material assets or conduct any business operations other than as disclosed to the Lenders. In addition, subject to certain exceptions, the Company and Ocera Subsidiary, Inc., are required to maintain with SVB their respective primary deposit accounts, securities accounts and commodity accounts. The Loan Agreement also contains customary indemnification obligations and customary events of default, including, among other things, our failure to fulfill certain of the Company's obligations under the Loan Agreement, the occurrence of a material adverse change in the Company's business, operations, or condition (financial or otherwise), a material impairment of the prospect of repayment of any portion of the loan, or a material impairment in the perfection or priority of the Lenders’ lien in the collateral or in the value of such collateral. In the event of default by the Company under the Loan Agreement, the Lenders would be entitled to exercise their remedies thereunder, including the right to accelerate the debt, upon which the Company may be required to repay all amounts then outstanding under the Loan Agreement, which could harm the Company's financial condition. The Company was in compliance with all applicable covenants set forth in the Loan Agreement as of December 31, 2016 and 2015 . The principal payments due under the Loan Agreement have been classified as a current liability at December 31, 2016 due to the considerations discussed in Note 1 and the assessment that the material adverse change clause under the Loan Agreement is not within the Company's control. The Company has not been notified of an event of default by the Lenders as of the date of the filing of this Form 10-K. The Company recorded interest expense related to the Term Loan Facility of $1.1 million and $0.5 million during the periods ended December 31, 2016 and 2015 . The annual effective interest rate on notes payable, including the amortization of the debt discounts and accretion of the final payments, is 11.72% . Future payments under the Loan Agreement as of December 31, 2016 are as follows (in thousands): Years Ending December 31: 2017 $ 3,839 2018 4,442 2019 3,261 Total future minimum payments 11,542 Less amount representing interest 1,542 Notes payable, gross 10,000 Unamortized discount on notes payable (297 ) Notes payable 9,703 Warrants The Company has issued warrants to purchase shares of its common stock to different entities in connection with legacy debt and equity financings. Additionally, the Company issued warrants in connection with the Term Loan Facility in July 2015 (see Notes Payable above). In 2016 , 22,265 warrants were exercised at an exercise price of $0.67 per share. In 2015 , 1,586 warrants were exercised at an exercise price of $0.67 per share. The Company’s outstanding warrants are exercisable for common stock at any time during their respective terms. The following table summarizes the outstanding common stock warrants and the corresponding exercise price as of December 31, 2016 and 2015 : Number of Warrants Outstanding at December 31 Per Share Exercise Issuance Date 2016 2015 Price Expiration 9/30/2010 3,240 3,240 $ 160.44 9/30/2017 1/31/2012 13,623 13,623 44.04 1/31/2022 3/30/2012 13,256 24,388 0.67 3/30/2019 6/30/2012 36,583 36,583 0.67 6/30/2019 10/1/2012 51,425 62,558 0.67 10/1/2019 11/8/2013 788,177 788,177 7.66 11/8/2018 7/30/2015 97,680 97,680 $ 4.10 7/30/2025 Total outstanding common stock warrants 1,003,984 1,026,249

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2016
Equity [Abstract]
Stockholders' Equity	Stockholders’ Equity On July 15, 2013, Private Ocera completed the Merger with Tranzyme as discussed in Note 1. Immediately prior to the effective time of the Merger, the principal and interest under Private Ocera's outstanding convertible notes converted into shares of Series C preferred stock of Private Ocera, and, immediately thereafter, all outstanding preferred stock of Private Ocera converted into the common stock of Private Ocera. At the effective time of the Merger, each outstanding share of Private Ocera's common stock was converted into shares of Tranzyme's common stock at the Exchange Ratio, with cash paid in lieu of any fractional shares. Pursuant to the Securities Purchase Agreement dated April 23, 2013, immediately following the Merger, the Company sold 3,317,976 shares of common stock at a per share price of $ 6.03 for approximately $20.0 million . Issuance costs of $26,000 were charged to additional paid-in capital. On November 8, 2013, the Company closed on a private placement pursuant to the Securities Purchase Agreement and sold an aggregate of 3,940,887 shares of common stock and warrants to purchase an additional 788,177 shares of common stock for an aggregate purchase price of $28.0 million . Issuance costs of $1.5 million were charged to additional paid-in capital. On July 10, 2014, the Company completed an underwritten public offering of its common stock in which 4,200,000 shares of common stock were sold for gross proceeds from the offering of $25.2 million . Issuance costs of $1.8 million were charged to additional paid-in capital. On May 15, 2015, the Company entered into a sales agreement (the “Sales Agreement”) with Cowen and Company, LLC (“Cowen”), pursuant to which the Company may issue and sell shares of its common stock having aggregate sales proceeds of up to $25.0 million from time to time through an “at the market” equity program under which Cowen acts as sales agent. During the year ended December 31, 2015 , the Company sold an aggregate of 946,497 shares of common stock under the Sales Agreement, at an average price of $3.95 per share, for net proceeds of $3.5 million after deducting commissions and other transaction costs. During the year ended December 31, 2016 , the Company sold an aggregate of 2,865,391 shares of common stock under the Sales Agreement, at an average price of $2.61 per share, for net proceeds of $7.1 million after deducting commissions and other transactions costs.

Stock Based Compensation

Stock Based Compensation	12 Months Ended
	Dec. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock Based Compensation	Stock-Based Compensation Equity Incentive Plans In 2005, the Company adopted the Ocera Therapeutics, Inc. 2005 Stock Plan (the "Plan"). At the effective time of the Merger, each outstanding stock option to purchase common stock of Private Ocera under the Plan not exercised immediately prior to the effective time of the Merger, whether or not vested, was assumed by the Company and became exercisable for shares of the Company's common stock in accordance with the terms of the Merger Agreement and the Company assumed the Plan. Upon completion of the Merger, no options remain available for future grant under the 2005 Plan. On July 15, 2013, in connection with the Merger, the Company assumed the existing Tranzyme 2011 Stock Option and Incentive Plan (the "2011 Plan"). As of December 31, 2016 the Company was authorized to issue 5,002,328 shares of common stock under the 2011 Plan. The 2011 Plan provides for the granting of incentive stock options, nonstatutory stock options, stock appreciation rights, restricted stock awards, restricted stock unit awards, performance stock awards, performance cash awards and other stock awards to employees, officers, directors and consultants. A summary of the Company's stock option activity under the 2011 Plan and related information are as follows (in thousands): Weighted Average Shares Weighted Average Remaining Aggregate Available Stock Options Exercise Price Contractual Intrinsic for Grant Outstanding Per Share Life (in Years) Value Balance at December 31, 2014 342,210 2,086,602 $ 8.01 8.63 $ 871 Additional shares authorized 1,300,000 Stock options granted (707,500 ) 707,500 3.73 Stock options exercised — — — Stock options canceled 364,591 (364,591 ) 6.44 Balance at December 31, 2015 1,299,301 2,429,511 7.00 8.01 287 Additional shares authorized 1,400,000 Stock options granted (2,341,350 ) 2,341,350 2.67 Stock options exercised — (23,938 ) 1.09 Stock options canceled 818,353 (818,353 ) 5.80 Balance at December 31, 2016 1,176,304 3,928,570 $ 4.71 7.83 119 At December 31, 2016: Vested and expected to vest 3,654,294 $ 4.85 7.72 $ 119 Vested and exercisable 1,639,838 $ 6.79 6.01 $ 119 The Company’s stock options generally vest over one to four years and have a ten -year contractual term. Stock-Based Compensation Expense: Stock-based compensation expense, net of estimated forfeitures, included in the consolidated statements of operations is as follows (in thousands): Years Ended December 31, 2016 2015 2014 Research and development $ 672 $ 648 $ 1,595 General and administrative 3,391 3,329 3,091 Total stock-based compensation expense $ 4,063 $ 3,977 $ 4,686 The above table includes immaterial amounts of stock compensation expense related to stock option grants to non-employee consultants for all periods presented. Stock Option Valuation Assumptions: The Company estimates the fair value of stock options using the Black-Scholes-Merton option-pricing model based on the date of grant. The following summarize the ranges of weighted-average assumptions used to estimate the fair value of stock options granted during each period: Years Ended December 31, 2016 2015 2014 Expected dividend yield —% —% —% Risk-free interest rate 0.59% - 2.20% 1.52% - 2.08% 1.74% - 2.01% Expected term (in years) 0.95 - 8.04 4.99 - 8.06 6.08 - 6.62 Expected volatility 73% - 94% 76% - 92% 95% - 102% The total estimated grant date fair value of stock options vested during the years ended December 31, 2016 is $3.8 million and for the years ended December 31, 2015 and 2014 is $4.1 million . The aggregate intrinsic value of options exercised during the years ended December 31, 2016 and 2015 , is insignificant and for the years ended December 31, 2014 is $2.7 million . As of December 31, 2016 , the Company had $5.5 million of unrecognized stock-based compensation expense which is expected to be recognized over a weighted average period of 2.40 years. On January 6, 2016 , the Company granted certain of its executive officers non-qualified stock options to purchase 206,625 shares of the Company’s common stock that vest on a monthly basis in equal installments over 48 months following the grant date if the Company's stock price equals or exceeds $6.00 for 20 consecutive trading days on or before June 30, 2017 . The options expire ten years from the date of the grant. The fair values of these options were determined using a Monte Carlo simulation model incorporating the following ranges of weighted-average assumptions: January 6, 2016 Expected dividend yield — Risk-free interest rate 1.82% - 2.05% Expected term (in years) 6.02 - 8.00 Expected volatility 77% - 89% Weighted-average fair value per share 1.33 - 1.42 The estimated expense for these awards is being recognized on an accelerated basis over the requisite service period with no adjustments in the future periods based upon the Company's actual common stock price. The Company recorded $0.2 million in stock-based compensation expense during the period ended December 31, 2016 in connection with such awards.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The following table presents consolidated loss before income taxes by income tax jurisdiction for continuing operations (in thousands): Years Ended December 31, 2016 2015 2014 United States $ (26,895 ) $ (26,749 ) $ (24,624 ) No provision for federal or state income taxes has been recorded, as the Company has incurred cumulative net operating losses since inception. A reconciliation of the loss from continuing operations at the federal statutory tax rate of 34% to the Company's effective income tax rate is as follows (in thousands): Years Ended December 31, 2016 2015 2014 Income tax benefit at statutory rate $ (9,144 ) $ (9,094 ) $ (8,372 ) State income tax, net of federal benefit 54 693 (4,180 ) Orphan drug expenses 998 817 1,045 Stock-based compensation 488 54 (45 ) Other permanent items 10 35 98 Tax credits (2,162 ) (1,769 ) (3,156 ) Change in valuation allowance 9,756 9,264 14,610 Provision for income taxes $ — $ — $ — Components of the Company's deferred tax assets and liabilities for federal and state income tax purposes are as follows (in thousands): Years Ended December 31, 2016 2015 Deferred tax assets: Net operating loss carryforwards $ 49,635 $ 42,754 Tax credit carryforwards 8,932 7,141 Stock-based compensation 4,164 3,162 Other 127 45 Deferred tax assets before valuation allowance 62,858 53,102 Valuation allowance (62,858 ) (53,102 ) Deferred tax assets: $ — $ — The Company has evaluated the evidence bearing upon the realizability of its net deferred tax assets including the Company's history of operating losses and has concluded that it is not more likely than not that the Company will realize the benefit of its deferred tax assets. Accordingly, the Company has recorded a full valuation allowance against its net deferred tax assets at December 31, 2016 and 2015 . As of December 31, 2016 , the Company has $131.6 million of United States federal net operating loss carryforwards and $10.7 million of orphan drug credit carryforwards, and $2.5 million of United States federal research and development carryforwards available for use, all of which have a full valuation allowance and will begin to expire in 2019 unless utilized. Not included in the deferred income tax asset balance at December 31, 2016 is approximately $0.3 million which pertains to certain net operating loss carryforwards resulting from the exercise of employee stock options, which to-date have not been recognized. As of December 31, 2016 , the Company has North Carolina net economic loss carryforwards of approximately $5.4 million , which will begin to expire in 2022 unless utilized, and $0.2 million of research and development credits that will begin to expire in 2028 unless utilized. As of December 31, 2016 , the Company has California state net operating loss carryforwards of approximately $63.1 million , which have begun to expire as of 2016, and $2.5 million of California research and development carryforwards that do not expire. Pursuant to Internal Revenue Code ("IRC") Sections 382 and 383, annual use of the Company’s net operating loss and research and development credit carryforwards may be limited in the event a cumulative change in ownership of more than 50% occurs within a three-year period. Additional limitations as to the ability to use net operating loss or tax credit carryforwards may arise if the Company experiences an ownership change in subsequent years. The Company has not performed a Section 382 or 383 analysis. As of December 31, 2016 , the Company had $6.0 million of unrecognized tax benefits. A reconciliation of the current and prior year changes to the Company’s unrecognized tax benefits is as follows (in thousands): Unrecognized tax benefits as of December 31, 2013 $ 1,840 Increases in prior period positions 647 Increases in current period positions 1,286 Unrecognized tax benefits as of December 31, 2014 3,773 Increases in prior period positions 8 Increases in current period positions 980 Unrecognized tax benefits as of December 31, 2015 4,761 Increases in prior period positions — Increases in current period positions 1,194 Unrecognized tax benefits as of December 31, 2016 $ 5,955 As of December 31, 2016 , no unrecognized tax benefits are included in the balance sheet that would, if recognized, affect the Company's effective tax rate due to the valuation allowance that currently offsets deferred tax assets. The Company does not anticipate the total amount of unrecognized income tax benefits will significantly increase or decrease in the next 12 months. The Company will recognize interest and penalties related to uncertain tax positions in income tax expense. The Company determined that no accrual for interest and penalties was required as of December 31, 2016 . The statute of limitations for assessment by the Internal Revenue Service ("IRS") and state tax authorities is open for tax years ended December 31, 2011 through 2016 , although carryforward attributes that were generated prior to tax year 2011 may still be adjusted upon examination by the IRS or state tax authorities if they either have been or will be used in a future period. There are currently no federal or state audits in progress.

Retirement Savings Plan

Retirement Savings Plan	12 Months Ended
	Dec. 31, 2016
Compensation and Retirement Disclosure [Abstract]
Retirement Savings Plan	Retirement Savings Plan The Company provides a qualified 401(k) savings plan for its employees. All employees are eligible to participate, provided they meet the requirements of the plan. Employee contributions are limited to a maximum annual amount as set periodically by the IRC. The Company provides a contribution on the first 3% of an employee's eligible compensation subject to statutory limitations as prescribed by law. For each of the years ended December 31, 2016 , 2015 , and 2014 , the Company recorded $0.1 million of expense associated with the matching of employee contributions.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies From time to time, the Company may be involved in disputes, including litigation, relating to claims arising out of operations in the normal course of our business. Any of these claims could subject the Company to costly legal expenses and, while the Company generally believes that it has adequate insurance to cover many different types of liabilities, our insurance carriers may deny coverage or our policy limits may be inadequate to fully satisfy any damage awards or settlements. If this were to happen, the payment of any such awards could have a material adverse effect on the Company's consolidated results of operations and financial position. Additionally, any such claims, whether or not successful, could damage our reputation and business. The Company is currently not a party to any legal proceedings, the adverse outcome of which, in management’s opinion, individually or in the aggregate, would have a material adverse effect on our consolidated results of operations or financial position. Indemnification As permitted under Delaware law and in accordance with the Company’s bylaws and agreements entered into with the Company’s officers and directors, the Company indemnifies its officers and directors for certain events or occurrences, subject to certain limits, while the officer or director is or was serving at the Company’s request in such capacity. The indemnification agreements with the Company’s officers and directors terminate upon termination of their employment, but the termination does not affect claims for indemnification relating to events occurring prior to the effective date of termination. The maximum amount of potential future indemnification is not limited; however, the Company’s director and officer insurance policy reduces the Company’s exposure and may enable the Company to recover a portion of any future amounts paid. In addition, the Company customarily agrees in the ordinary course of its business to indemnification provisions in its collaboration and licensing agreements, in agreements relating to the sale of assets, in various agreements involving parties performing services for the Company in the ordinary course of business and in its real estate leases. With respect to lease agreements, the indemnification provisions typically apply to claims asserted against the landlord relating to personal injury or property damage caused by the Company, to violations of law by the Company or to certain breaches of the Company’s contractual obligations. The indemnification provisions appearing in the Company’s collaboration and licensing agreements and in agreements relating to the sale of assets are similar, but in addition provide some limited indemnification for the collaborator, licensee or purchaser of assets in the event of third party claims alleging infringement of certain intellectual property rights or ownership rights. In each of the cases above, the indemnification obligation generally survives the termination of the agreement for some extended period, although the obligation typically has the most relevance during the contract term and for a short period of time thereafter. The maximum potential amount of future payments that the Company could be required to make under these provisions can be unlimited, but is sometimes limited by the value of payments made under the agreement or by an escrow amount. The Company has purchased insurance policies covering personal injury, property damage and general liability that reduce its exposure for indemnification and would enable it in many cases to recover a portion of any future amounts paid. The Company has never paid any material amounts to defend lawsuits or settle claims related to these indemnification provisions. The Company accrues for known indemnification issues when a loss is probable and can be reasonably estimated. There were no accruals for expenses related to indemnification issues for each of the years ended December 31, 2016 and 2015 . Purchase Commitments In November 2016, the Company entered into an agreement with Evonik, under which Evonik will manufacture clinical supply of OCR-002 drug substance for the Company. Per the terms of the agreement, the Company will purchase clinical supply of OCR-002 totaling $1.3 million . As of December 31, 2016, the Company has paid $0.4 million to Evonik and is subject to a cancellation fee of $0.8 million . Facilities The Company leases its corporate, laboratory and other facilities under operating leases which have been subject to several amendments necessary to secure additional space and/or extend the lease term. In October 2013 , the Company entered into an agreement to sublease office space located at 525 University Avenue, Palo Alto, California for the period from October 10, 2013 to December 31, 2016 . These premises serve as the Company's corporate headquarters. In December 2016 , the Company amended the sublease for this facility by extending term of the lease to June 30, 2017 . The Company does not have an option to extend the sublease term beyond June 30, 2017 . Upon the Merger, the Company obtained office space located at 5001 South Miami Boulevard, Durham, North Carolina under a lease agreement. In May 2016 , the Company amended the lease for this facility by extending term of the lease through January 31, 2018 . In May 2016 , the Company entered into an agreement to sublease office space located at 100 Lakeview Parkway, Vernon Hills, Illinois under a lease agreement that will expire on May 31, 2018 . The lease includes an option to extend the lease term to J anuary 2021 . Provisions of these facilities leases generally provide for abatement of rent during certain periods and escalating rent payments during the original and extended lease terms. Rent expense is being recorded on a straight-line basis over the life of the lease. Rent expense was $0.4 million , $0.3 million , $0.2 million for the years ended December 31, 2016 , 2015 and 2014 , respectively. The following is a schedule of non-cancelable future minimum lease payments for operating leases at December 31, 2016 (in thousands): Years Ending December 31, 2017 $ 361 2018 49 2019 and beyond 8 Total future minimum lease payments for operating leases $ 418

Subsequent Event (Notes)

Subsequent Event (Notes)	12 Months Ended
	Dec. 31, 2016
Subsequent Events [Abstract]
Subsequent Event	Subsequent Event Pursuant to the Company's "at the market" equity program, in March 2017, prior to the date of the filing of this Form 10-K, the Company sold an aggregate of 1,835,425 shares of common stock under the Sales Agreement at an average price of approximately $1.57 per share, for net proceeds of approximately $2.8 million .

Summary of Operations by Quarte

Summary of Operations by Quarter (Unaudited)	12 Months Ended
	Dec. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
Summary of Operations by Quarter (Unaudited)	Summary of Operations by Quarter (Unaudited) The following tables present certain unaudited quarterly financial information. This information has been prepared on the same basis as the audited consolidated financial statements and includes all normal recurring adjustments necessary to present fairly the unaudited quarterly results of operations set forth herein (in thousands, except per share amounts): Year Ended December 31, 2016: Quarter (1) First Second Third Fourth Revenues $ 33 $ 26 $ 38 $ 512 Operating expenses 7,301 6,879 6,901 5,408 Net loss (7,514 ) (7,103 ) (7,125 ) (5,153 ) Net loss per share, basic and diluted (0.36 ) (0.33 ) (0.32 ) (0.22 ) Weighted average common shares outstanding used to compute net loss per share, basic and diluted 20,943,966 21,552,089 22,096,610 23,223,569 Year Ended December 31, 2015: Quarter (1) First Second Third Fourth Revenues $ 31 $ 43 $ 35 $ 24 Operating expenses 6,695 6,290 6,648 6,836 Net loss from continuing operations (6,651 ) (6,221 ) (6,793 ) (7,084 ) Net loss (6,651 ) (6,221 ) (6,574 ) (7,076 ) Net loss per share from continuing operations, basic and diluted (0.34 ) (0.31 ) (0.34 ) (0.34 ) Net loss per share, basic and diluted (0.34 ) (0.31 ) (0.33 ) (0.34 ) Weighted average common shares outstanding used to compute net loss per share, basic and diluted 19,747,362 19,772,345 20,183,939 20,556,822 (1) Quarterly results may not sum precisely to annual totals due to rounding. Because of the method used in calculating per share data, the quarterly per share data will not necessarily add to the per share data as computed for the year.

Summary of Significant Accoun22

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2016
Accounting Policies [Abstract]
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with United States GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Actual results could differ from those estimates.
Goodwill	The Company recorded goodwill upon the Merger. The Company performs an impairment test of goodwill annually and whenever events or changes in circumstances indicate that the carrying amount may not be recoverable.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers all highly liquid investments with original maturities of three months or less at the date of purchase to be cash equivalents. Cash and cash equivalents include money market funds and various deposit accounts.
Segment Reporting	Segment Reporting Operating segments are identified as components of an enterprise about which separate discrete financial information is available for evaluation by the chief operating decision maker in deciding how to allocate resources and in assessing performance.
Concentration of Credit Risk	Concentration of Credit Risk Financial instruments that potentially subject the Company to a significant concentration of credit risk consist primarily of cash and cash equivalents and investments in marketable securities. The Company maintains deposits in federally insured financial institutions in excess of federally insured limits. However, management believes the Company is not exposed to significant credit risk due to the financial position of the depository institutions in which those deposits are held. Additionally, the Company has established guidelines regarding diversification of its investments in marketable securities and their maturities, which are designed to maintain safety and liquidity.
Investments in marketable securities	Investments in Marketable Securities The Company invests in marketable securities, primarily money market funds, commercial paper, government agency debt securities and United States and foreign corporate debt securities. Investments with original maturities greater than 90 days that mature less than one year from the consolidated balance sheet date are classified as short-term investments. Those investments with a maturity date greater than one year at each balance sheet date are considered to be long-term investments. The Company further classifies investments as short-term or long-term based upon whether such assets are reasonably expected to be realized in cash or sold or consumed during the normal cycle of business. As of December 31, 2016 and 2015 all investments in marketable securities were classified as available-for-sale and are carried at estimated fair value as determined based upon quoted market prices or pricing models for similar securities. Unrealized gains and losses are excluded from earnings and are reported as a component of accumulated comprehensive income (loss). Realized gains and losses and declines in fair value judged to be other than temporary, if any, on investments in marketable securities are included in interest and other income (expense), net. The cost of securities sold is based on the specific-identification method. Interest earned on investments in marketable securities is included in interest and other income. Debt securities are adjusted for amortization of premiums and accretion of discounts and such amortization and accretion are reported as a component of interest and other income.
Fair Value Measurement	Fair Value Measurements Fair value accounting is applied for all financial assets and liabilities and non-financial assets and liabilities that are recognized or disclosed at fair value in the financial statements on a recurring basis. Fair value is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. Where available, fair value is based on or derived from observable market prices or other observable inputs. Where observable prices or inputs are not available, valuation models are applied. These valuation techniques may involve some level of management estimation and judgment, the degree of which is dependent on the price transparency for the instruments and the instruments’ complexity. The fair value hierarchy prioritizes the inputs to valuation techniques used to measure fair value into three broad levels. All of the Company's cash equivalents and investments are measured using inputs classified at Level 1 or Level 2 within the fair value hierarchy. Level 1 inputs are quoted prices in active markets for identical assets. The Company classifies money market funds as Level 1. Level 2 inputs are based upon quoted prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active and model-based valuation techniques for which all significant inputs are observable in the market or can be corroborated by observable market data for substantially the full term of the assets. The Company’s classifies its commercial paper and corporate debt securities as Level 2. Level 3 inputs are unobservable inputs that are supported by little or no market activity and are significant to the fair value of the assets or liabilities. Where applicable, these models project future cash flows and discount the future amounts to a present value using market-based observable inputs obtained from various third-party data providers, including but not limited to, benchmark yields, interest rate curves, reported trades, broker/dealer quotes and market reference data.
Property and Equipment, Net	Property and Equipment, net Property and equipment, net, are stated at cost less accumulated depreciation. Depreciation is calculated using the straight-line method over the estimated useful lives of the assets. Useful lives generally range from three to five years .
Revenue Recognition	Revenue Recognition The Company recognizes revenue from licensing agreements for the development and commercialization of products and royalties from the use of our intellectual property. License fees from license agreements are recognized when the amounts are earned. Royalty revenues are recorded based on sales information provided by the Company's licensors.
Research and development	Research and Development Research and development costs are expensed as incurred and consist of salaries and benefits, lab supplies, materials and facility costs, as well as fees paid to other non-employees and entities that conduct certain research and development activities on our behalf. Payments made prior to the receipt of goods or services to be used in research and development are capitalized until the goods are received or services are rendered.
Share-based Compensation	Stock-Based Compensation Employee stock-based compensation is recognized as an expense in the financial statements based on the grant date fair value of the award. For awards that vest based on service conditions, the Company records compensation expense, net of estimated forfeitures, on a straight-line basis over the requisite service period which is generally the vesting period for the related award. For performance-based stock options, the Company evaluates the probability of achieving performance-based goals at each reporting date. The Company begins to recognize the expense when it is deemed probable that the performance-based goal will be met. The Company records equity grants to non-employees as expense at their fair value over the related service period and periodically revalues them at each reporting period over the vesting term. The Company estimates the fair value of stock options using a Black-Scholes-Merton option-pricing model which requires the input of highly subjective assumptions that represent our best estimates of volatility, risk-free interest rate, expected life, and dividend yield. The Company estimates expected volatility based on its own historical volatility supplemented by a review of historical volatilities of industry peers. The Company has, due to insufficient historical data, used the "simplified method," as described in Staff Accounting Bulletin No. 107, "Share-Based Payment," to determine the expected life of stock options granted with a service condition. The risk-free rate assumption was based on United States Treasury instruments whose terms were consistent with the expected term of the stock options. The expected dividend assumption was based on our history and expectation of dividend payouts. The Company accounts for stock-based compensation arrangements with non-employees using a fair value approach. The fair value of these options is measured using the Black-Scholes-Merton option pricing model reflecting the same assumptions as applied to employee options in each of the reported periods, other than the expected life, which is assumed to be the remaining contractual life of the option. The compensation costs of these arrangements are subject to remeasurement over the vesting terms as earned. The Company estimates fair value of stock options with market-based vesting conditions based on Monte Carlo simulation models with assistance from an independent third-party valuation specialist. The Monte Carlo simulation models require the use of highly subjective and complex assumptions which determine the fair value of such awards including price volatility of the underlying stock and derived service periods. The assumptions used in calculating the fair value of stock options with market-based vesting conditions and expected attainment of performance conditions for performance-based stock options represent our best estimates, but these estimates involve inherent uncertainties and the application of management’s judgment. Future expense amounts for any particular period could be affected by changes in the Company's assumptions.
Income Taxes	Income Taxes The Company accounts for income taxes under the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements. Under this method, the Company determines deferred tax assets and liabilities on the basis of the differences between the financial statement and tax basis of assets and liabilities by using enacted tax rates in effect for the year in which the differences are expected to reverse. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in income in the period that includes the enactment date. The Company recognizes deferred tax assets to the extent that it believes that these assets are more likely than not to be realized. In making such a determination, it considers all available positive and negative evidence, including future reversals of existing taxable temporary differences, projected future taxable income, tax-planning strategies, and results of recent operations. If it is determined that the Company would be able to realize deferred tax assets in the future in excess of their net recorded amount, it would make an adjustment to the deferred tax asset valuation allowance, which would reduce the provision for income taxes. The recognition and measurement of tax benefits requires significant judgment. Judgments concerning the recognition and measurement of tax benefit might change as new information becomes available. The Company records uncertain tax positions on the basis of a two-step process in which (1) it determines whether it is more likely than not that the tax positions will be sustained on the basis of the technical merits of the position and (2) for those tax positions that meet the more-likely-than-not recognition threshold, the Company recognizes the largest amount of tax benefit that is more than 50 percent likely to be realized upon ultimate settlement with the related tax authority. The Company's policy is to recognize interest and penalties related to the underpayment of income taxes as a component of income tax expense or benefit. To date, there have been no interest or penalties charged in relation to the underpayment of income taxes.
Recent Accounting Pronouncements	Recent Accounting Pronouncements Occasionally, new accounting standards are issued or proposed by the Financial Accounting Standards Board (the "FASB"), or other standards-setting bodies that the Company adopts by the effective date specified within the standard. Unless otherwise discussed, standards that do not require adoption until a future date are not expected to have a material impact on the Company's financial statements upon adoption. In August 2014, the FASB issued Accounting Standards Update ("ASU") 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. The standard requires management to assess, at each annual and interim reporting period, whether there are conditions or events that raise substantial doubt about the entity’s ability to continue as a going concern and provide related disclosures in certain circumstances. The Company adopted the guidance as of December 31, 2016 and has included disclosures on this topic in Note 1. In August 2016, the FASB issued ASU 2016-15, Classification of Certain Cash Receipts and Cash Payments, which aims to eliminate diversity in practice in how certain cash receipts and cash payments are presented and classified in the statement of cash flows under Topic 230, Statement of Cash Flows, and other Topics. ASU 2016-15 is effective for annual reporting periods, and interim periods therein, beginning after December 15, 2017. The Company continues to assess the potential impact of this standard, but currently does not expect the adoption of this standard 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 (Topic 718), Compensation - Stock Compensation. The ASU simplifies several aspects of the accounting for share-based payments, including the income tax consequences, changing the threshold to qualify for equity classification to the employees' maximum statutory tax rates, allowing an entity-wide accounting policy election to either estimate the number of awards that are expected to vest or account for forfeitures as they occur, and clarifying the classification on the statement of cash flows for the excess tax benefit and employee taxes paid when an employer withholds shares for tax-withholding purposes. ASU 2016-09 is effective for annual reporting periods beginning after December 15, 2016, and interim periods within that reporting period. The Company will adopt this standard in the first quarter of fiscal year 2017 and is currently evaluating the impact of the guidance on its consolidated financial statements. In February 2016, the FASB issued ASU 2016-02, Leases, to increase transparency and comparability among organizations by requiring recognition of lease assets and lease liabilities on the balance sheet and disclosure of key information about leasing arrangements. The standard will become effective for interim and annual periods beginning after December 15, 2018, with early adoption permitted. The guidance is required to be adopted at the earliest period presented using a modified retrospective approach. The Company is currently evaluating the impact of the adoption of this standard on its consolidated financial statements. In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers. The standard’s core principle is that a reporting entity will recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The standard will become effective for the Company beginning in the first quarter of 2018. Early adoption is permitted in 2017. Entities have the option of using either a full retrospective or a modified retrospective approach to adopt this new guidance. In March and April 2016, the FASB issued ASU 2016-08 Revenue From Contracts With Customers: Principal vs. Agent Considerations and ASU 2016-10 Revenue From Contracts with Customers: Identifying Performance Obligations and Licensing to provide supplemental adoption guidance and clarification to ASU 2014-09. The Company plans to adopt this guidance as of January 1, 2018, using the modified retrospective method and is in the process of evaluating its arrangements where it has licensed or sold intellectual property. The Company has not completed the full assessment and is not able to estimate the anticipated impact to the consolidated financial statements from the application of the new standard. The Company reviewed all other recently issued accounting pronouncements and concluded that they were either not applicable or not expected to have a significant impact to the consolidated financial statements. Additionally, the adoption of accounting pronouncements during 2016 did not have an impact on the Company’s consolidated financial position or results of operations.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2016
Fair Value Disclosures [Abstract]
Assets and Liabilities Measured at Fair Value on a Recurring Basis	Assets and liabilities measured at fair value on a recurring basis as of December 31, 2016 are as follows (in thousands): Total Level 1 Level 2 Level 3 Assets: Money market funds $ 24,593 $ 24,593 $ — $ — Commercial paper 1,498 — 1,498 — Corporate debt securities 2,251 — 2,251 — Total assets $ 28,342 $ 24,593 $ 3,749 $ — The estimated fair value of the Company's notes payable, considering level 2 inputs, approximates their carrying value based upon the borrowing terms and conditions available to the Company at December 31, 2016 . Assets and liabilities measured at fair value on a recurring basis as of December 31, 2015 are as follows (in thousands): Total Level 1 Level 2 Level 3 Assets: Money market funds $ 34,806 $ 34,806 $ — $ — Corporate debt securities 7,415 — 7,415 — Total assets $ 42,221 $ 34,806 $ 7,415 $ — The estimated fair value of the Company's notes payable, considering level 2 inputs, approximates their carrying value based upon the borrowing terms and conditions available to the Company at December 31, 2015 .

Balance Sheet Components (Table

Balance Sheet Components (Tables)	12 Months Ended
	Dec. 31, 2016
Balance Sheet Components [Abstract]
Summary of Available for Sale Investments	The following table summarizes the Company's cash equivalents and marketable securities as of December 31, 2016 (in thousands): Maturity Amortized Cost Unrealized Gains Unrealized Losses Estimated Fair Value Money market funds (1) n/a $ 24,593 $ — $ — $ 24,593 Commercial paper 1 or less 1,498 — — 1,498 Corporate debt securities 1 or less 2,251 — — 2,251 Total cash equivalents and marketable securities $ 28,342 $ — $ — $ 28,342 (1) Money market funds are classified in cash and cash equivalents on our consolidated balance sheets. The following table summarizes the Company's cash equivalents and marketable securities as of December 31, 2015 (in thousands): Maturity (in Years) Amortized Cost Unrealized Gains Unrealized Losses Estimated Fair Value Money market funds (1) n/a $ 34,806 $ — $ — $ 34,806 Corporate debt securities 1 or less 7,420 — (5 ) 7,415 Total cash equivalents and marketable securities $ 42,226 $ — $ (5 ) $ 42,221 (1) Money market funds are classified in cash and cash equivalents on our consolidated balance sheets.
Schedule of Accrued Liabilities	Accrued liabilities consisted of the following (in thousands): December 31, 2016 2015 Clinical trials $ 1,519 $ 1,666 Compensation and related expenses 1,124 993 Professional services 102 319 Interest expense and other 94 155 Total accrued liabilities $ 2,839 $ 3,133

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	12 Months Ended
	Dec. 31, 2016
Earnings Per Share [Abstract]
Schedule of Earnings Per Share	The following table presents the computation of net loss per share (in thousands, except share and per share data): Years Ended December 31, 2016 2015 2014 Numerator Net loss from continuing operations $ (26,895 ) $ (26,749 ) $ (24,624 ) Net income from discontinued operations — 227 1,199 Net loss $ (26,895 ) $ (26,522 ) $ (23,425 ) Denominator Weighted average common shares outstanding used to compute net loss per share, basic and diluted 21,957,917 20,067,660 17,525,187 Net loss per share of common stock, basic and diluted: Net loss per share from continuing operations $ (1.22 ) $ (1.33 ) $ (1.41 ) Net income per share from discontinued operations — 0.01 0.07 Net loss per share $ (1.22 ) $ (1.32 ) $ (1.34 )
Schedule of Antidilutive Securities Excluded from Computation	The following common stock equivalents were excluded from the computation of diluted net loss per share for the periods presented because their effect would be antidilutive. Years Ended December 31, 2016 2015 2014 Common stock warrants 1,003,984 1,026,249 932,535 Common stock options outstanding 3,928,570 2,429,511 2,086,602 Total potentially dilutive securities 4,932,554 3,455,760 3,019,137

Debt (Tables)

Debt (Tables)	12 Months Ended
	Dec. 31, 2016
Debt Disclosure [Abstract]
Schedule of maturities	Future payments under the Loan Agreement as of December 31, 2016 are as follows (in thousands): Years Ending December 31: 2017 $ 3,839 2018 4,442 2019 3,261 Total future minimum payments 11,542 Less amount representing interest 1,542 Notes payable, gross 10,000 Unamortized discount on notes payable (297 ) Notes payable 9,703
Schedule of Outstanding Convertible Preferred and Common Stock Warrants and Corresponding Exercise Price	The following table summarizes the outstanding common stock warrants and the corresponding exercise price as of December 31, 2016 and 2015 : Number of Warrants Outstanding at December 31 Per Share Exercise Issuance Date 2016 2015 Price Expiration 9/30/2010 3,240 3,240 $ 160.44 9/30/2017 1/31/2012 13,623 13,623 44.04 1/31/2022 3/30/2012 13,256 24,388 0.67 3/30/2019 6/30/2012 36,583 36,583 0.67 6/30/2019 10/1/2012 51,425 62,558 0.67 10/1/2019 11/8/2013 788,177 788,177 7.66 11/8/2018 7/30/2015 97,680 97,680 $ 4.10 7/30/2025 Total outstanding common stock warrants 1,003,984 1,026,249

Stock Based Compensation (Table

Stock Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Summary of Stock Option Activity	A summary of the Company's stock option activity under the 2011 Plan and related information are as follows (in thousands): Weighted Average Shares Weighted Average Remaining Aggregate Available Stock Options Exercise Price Contractual Intrinsic for Grant Outstanding Per Share Life (in Years) Value Balance at December 31, 2014 342,210 2,086,602 $ 8.01 8.63 $ 871 Additional shares authorized 1,300,000 Stock options granted (707,500 ) 707,500 3.73 Stock options exercised — — — Stock options canceled 364,591 (364,591 ) 6.44 Balance at December 31, 2015 1,299,301 2,429,511 7.00 8.01 287 Additional shares authorized 1,400,000 Stock options granted (2,341,350 ) 2,341,350 2.67 Stock options exercised — (23,938 ) 1.09 Stock options canceled 818,353 (818,353 ) 5.80 Balance at December 31, 2016 1,176,304 3,928,570 $ 4.71 7.83 119 At December 31, 2016: Vested and expected to vest 3,654,294 $ 4.85 7.72 $ 119 Vested and exercisable 1,639,838 $ 6.79 6.01 $ 119
Stock-Based Compensation Expense	Years Ended December 31, 2016 2015 2014 Research and development $ 672 $ 648 $ 1,595 General and administrative 3,391 3,329 3,091 Total stock-based compensation expense $ 4,063 $ 3,977 $ 4,686
Stock Option Valuation Assumptions	Years Ended December 31, 2016 2015 2014 Expected dividend yield —% —% —% Risk-free interest rate 0.59% - 2.20% 1.52% - 2.08% 1.74% - 2.01% Expected term (in years) 0.95 - 8.04 4.99 - 8.06 6.08 - 6.62 Expected volatility 73% - 94% 76% - 92% 95% - 102% The fair values of these options were determined using a Monte Carlo simulation model incorporating the following ranges of weighted-average assumptions: January 6, 2016 Expected dividend yield — Risk-free interest rate 1.82% - 2.05% Expected term (in years) 6.02 - 8.00 Expected volatility 77% - 89% Weighted-average fair value per share 1.33 - 1.42

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Schedule of Income Before Income Tax	The following table presents consolidated loss before income taxes by income tax jurisdiction for continuing operations (in thousands): Years Ended December 31, 2016 2015 2014 United States $ (26,895 ) $ (26,749 ) $ (24,624 )
Effective Income Tax Rate Reconciliation	A reconciliation of the loss from continuing operations at the federal statutory tax rate of 34% to the Company's effective income tax rate is as follows (in thousands): Years Ended December 31, 2016 2015 2014 Income tax benefit at statutory rate $ (9,144 ) $ (9,094 ) $ (8,372 ) State income tax, net of federal benefit 54 693 (4,180 ) Orphan drug expenses 998 817 1,045 Stock-based compensation 488 54 (45 ) Other permanent items 10 35 98 Tax credits (2,162 ) (1,769 ) (3,156 ) Change in valuation allowance 9,756 9,264 14,610 Provision for income taxes $ — $ — $ —
Deferred Tax Assets and Liabilities	Components of the Company's deferred tax assets and liabilities for federal and state income tax purposes are as follows (in thousands): Years Ended December 31, 2016 2015 Deferred tax assets: Net operating loss carryforwards $ 49,635 $ 42,754 Tax credit carryforwards 8,932 7,141 Stock-based compensation 4,164 3,162 Other 127 45 Deferred tax assets before valuation allowance 62,858 53,102 Valuation allowance (62,858 ) (53,102 ) Deferred tax assets: $ — $ —
Summary of Unrecognized Tax Benefits	A reconciliation of the current and prior year changes to the Company’s unrecognized tax benefits is as follows (in thousands): Unrecognized tax benefits as of December 31, 2013 $ 1,840 Increases in prior period positions 647 Increases in current period positions 1,286 Unrecognized tax benefits as of December 31, 2014 3,773 Increases in prior period positions 8 Increases in current period positions 980 Unrecognized tax benefits as of December 31, 2015 4,761 Increases in prior period positions — Increases in current period positions 1,194 Unrecognized tax benefits as of December 31, 2016 $ 5,955

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Schedule of Non-Cancellable Future Minimum Lease Payments for Operating Leases	The following is a schedule of non-cancelable future minimum lease payments for operating leases at December 31, 2016 (in thousands): Years Ending December 31, 2017 $ 361 2018 49 2019 and beyond 8 Total future minimum lease payments for operating leases $ 418

Summary of Operations by Quar30

Summary of Operations by Quarter (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
Summary of Operations by Quarter	Summary of Operations by Quarter (Unaudited) The following tables present certain unaudited quarterly financial information. This information has been prepared on the same basis as the audited consolidated financial statements and includes all normal recurring adjustments necessary to present fairly the unaudited quarterly results of operations set forth herein (in thousands, except per share amounts): Year Ended December 31, 2016: Quarter (1) First Second Third Fourth Revenues $ 33 $ 26 $ 38 $ 512 Operating expenses 7,301 6,879 6,901 5,408 Net loss (7,514 ) (7,103 ) (7,125 ) (5,153 ) Net loss per share, basic and diluted (0.36 ) (0.33 ) (0.32 ) (0.22 ) Weighted average common shares outstanding used to compute net loss per share, basic and diluted 20,943,966 21,552,089 22,096,610 23,223,569 Year Ended December 31, 2015: Quarter (1) First Second Third Fourth Revenues $ 31 $ 43 $ 35 $ 24 Operating expenses 6,695 6,290 6,648 6,836 Net loss from continuing operations (6,651 ) (6,221 ) (6,793 ) (7,084 ) Net loss (6,651 ) (6,221 ) (6,574 ) (7,076 ) Net loss per share from continuing operations, basic and diluted (0.34 ) (0.31 ) (0.34 ) (0.34 ) Net loss per share, basic and diluted (0.34 ) (0.31 ) (0.33 ) (0.34 ) Weighted average common shares outstanding used to compute net loss per share, basic and diluted 19,747,362 19,772,345 20,183,939 20,556,822 (1) Quarterly results may not sum precisely to annual totals due to rounding.

Description of Business and B31

Description of Business and Basis of Presentation (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Class of Stock [Line Items]
Accumulated deficit	$ (158,328)	$ (131,433)

Summary of Significant Accoun32

Summary of Significant Accounting Policies (Segment Reporting & Property and Equipment) (Details)	12 Months Ended
	Dec. 31, 2016segment
Accounting Policies [Abstract]
Number of operating segments	1
Minimum
Property, Plant and Equipment [Line Items]
Useful lives (in years)	3 years
Maximum
Property, Plant and Equipment [Line Items]
Useful lives (in years)	5 years

Summary of Significant Accoun33

Summary of Significant Accounting Policies (Intangible Assets and Goodwill) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Finite-Lived Intangible Assets [Line Items]
Impairment of goodwill	$ 0	$ 0	$ 0

Fair Value Measurements (Fair V

Fair Value Measurements (Fair Value) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	$ 24,611	$ 35,921	$ 10,127	$ 15,533
Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	28,342	42,221
Recurring | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets		34,806
Recurring | Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	1,498
Recurring | Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	2,251	7,415
Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	24,593	34,806
Recurring | Level 1 | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	24,593	34,806
Recurring | Level 1 | Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	0
Recurring | Level 1 | Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	0	0
Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	3,749	7,415
Recurring | Level 2 | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	0	0
Recurring | Level 2 | Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	1,498
Recurring | Level 2 | Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	2,251	7,415
Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	0	0
Recurring | Level 3 | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	0	0
Recurring | Level 3 | Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	0
Recurring | Level 3 | Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	$ 0	$ 0

Balance Sheet Components (Avail

Balance Sheet Components (Available For Sale Investments) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Schedule of Available-for-sale Securities [Line Items]
Cash and cash equivalents	$ 24,611	$ 35,921	$ 10,127	$ 15,533
Cash equivalents and marketable securities, Amortized Cost	28,342	42,226
Cash equivalents and marketable securities, Unrealized Gains	0	0
Cash equivalents and marketable securities, Unrealized Losses	0	5
Cash equivalents and marketable securities, Estimated Fair Value	28,342	42,221
Short-term investments | Commercial paper
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	1,498
Unrealized Gains	0
Unrealized Losses	0
Estimated Fair Value	1,498
Short-term investments | Corporate debt securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	2,251	7,420
Unrealized Gains	0	0
Unrealized Losses	0	(5)
Estimated Fair Value	2,251	7,415
Money market funds
Schedule of Available-for-sale Securities [Line Items]
Cash and cash equivalents	$ 24,593	$ 34,806

Balance Sheet Components (Accru

Balance Sheet Components (Accrued Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Balance Sheet Components [Abstract]
Clinical trials	$ 1,519	$ 1,666
Compensation and related expenses	1,124	993
Professional services	102	319
Interest expense and other	94	155
Accrued liabilities	$ 2,839	$ 3,133

Discontinued Operations (Discon

Discontinued Operations (Discontinued Operations in the Company's Consolidated Statement of Financial Position) (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2014	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net income from discontinued operations		$ 0	$ 227	$ 1,199
Tranzyme Pharma Inc.
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net gain on disposal of assets				$ 1,100
Net income from discontinued operations			$ 200
Customer Agreements And Intellectual Property [Member] | Tranzyme Pharma Inc.
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds recognized pursuant to Technology Transfer and License Agreement	$ 4,000

License Agreements and Acquir38

License Agreements and Acquired Development and Commericialization Rights (Details) - USD ($)	1 Months Ended	12 Months Ended
	Dec. 31, 2008	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Open Biosystems, Inc.
Acquired Finite-Lived Intangible Assets [Line Items]
Long-term commitment, term		12 years
Royalty revenues		$ 509,000	$ 133,000	$ 141,000
Royalty paid		500,000
Licensing Agreements | UCL Business PLC
Acquired Finite-Lived Intangible Assets [Line Items]
Up-front fee for licensing	$ 1,000,000
Maximum future milestone payments		20,000,000
Licensing Agreements | OCR-002
Acquired Finite-Lived Intangible Assets [Line Items]
Maximum future milestone payments		35,000,000
Intellectual Property And Licensing Agreements
Acquired Finite-Lived Intangible Assets [Line Items]
Licensing revenue				200,000
Revenue recognized		$ 100,000
Contingent consideration, asset, range of outcomes, value, high				$ 25,000,000

Net Loss Per Share (Schedule of

Net Loss Per Share (Schedule of Basic and Diluted Earnings Per Share) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Numerator
Net loss from continuing operations					$ (7,084)	$ (6,793)	$ (6,221)	$ (6,651)	$ (26,895)	$ (26,749)	$ (24,624)
Net income from discontinued operations									0	227	1,199
Net loss	$ (5,153)	$ (7,125)	$ (7,103)	$ (7,514)	$ (7,076)	$ (6,574)	$ (6,221)	$ (6,651)	$ (26,895)	$ (26,522)	$ (23,425)
Denominator
Weighted average number of shares used to compute net loss per share of common stock, basic and diluted (shares)	23,223,569	22,096,610	21,552,089	20,943,966	20,556,822	20,183,939	19,772,345	19,747,362	21,957,917	20,067,660	17,525,187
Net loss per share of common stock, basic and diluted:
Net loss per share from continuing operations, basic and diluted (in dollars per share)					$ (0.34)	$ (0.34)	$ (0.31)	$ (0.34)	$ (1.22)	$ (1.33)	$ (1.41)
Net loss per share from discontinued operations, basic and diluted (in dollars per share)									0	0.01	0.07
Net loss per share, basic and diluted (in dollars per share)	$ (0.22)	$ (0.32)	$ (0.33)	$ (0.36)	$ (0.34)	$ (0.33)	$ (0.31)	$ (0.34)	$ (1.22)	$ (1.32)	$ (1.34)

Net Loss Per Share (Schedule 40

Net Loss Per Share (Schedule of Antidilutive Securities Excluded From Computation) (Details) - shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	4,932,554	3,455,760	3,019,137
Warrant | Common Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	1,003,984	1,026,249	932,535
Stock Options | Common Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	3,928,570	2,429,511	2,086,602

Debt (Notes Payable) (Details)

Debt (Notes Payable) (Details) - USD ($)	Jul. 30, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Debt Instrument [Line Items]
Expired borrowing capacity		$ 10,000,000
Other Nonoperating Interest And Other Expense		1,124,000	$ 502,000	$ 12,000
Oxford Finance LLC and Silicon Valley Bank | Secured Debt | Notes Payable, Other Payables
Debt Instrument [Line Items]
Stated interest rate (percentage)	8.275%
Additional interest	3.00%
Warrant
Debt Instrument [Line Items]
Face amount covered by warrant or right (percentage)	4.00%
Number shares called by each warrant (shares)	97,680
Exercise price of warrants (usd per share)	$ 4.095
Warrants outstanding, value	$ 300,000
Risk free interest rate (percentage)	2.28%
Expected volatility rate (percentage)	87.00%
Expected term (years)	10 years
Dividend yield (percentage)	0.00%
Share price (usd per share)	$ 3.84
Minimum | Oxford Finance LLC and Silicon Valley Bank | Secured Debt | Notes Payable, Other Payables
Debt Instrument [Line Items]
Early extinguishment of debt, prepayment fee	1.00%
Notes Payable, Other Payables | Oxford Finance LLC and Silicon Valley Bank | Secured Debt
Debt Instrument [Line Items]
Debt instrument, maximum borrowing capacity	$ 20,000,000
Notes payable, gross	10,000,000	$ 10,000,000
Proceeds from debt, net of issuance costs	9,700,000
Legal and consulting fees	$ 300,000
Notes Payable, Other Payables | Maximum | Oxford Finance LLC and Silicon Valley Bank | Secured Debt
Debt Instrument [Line Items]
Early extinguishment of debt, prepayment fee	3.00%
Term Loan Facility | Line of Credit
Debt Instrument [Line Items]
Effective interest rate (percentage)		11.72%

Debt (Schedule of Debt) (Detail

Debt (Schedule of Debt) (Details) - Notes Payable, Other Payables - USD ($)	Dec. 31, 2016	Jul. 30, 2015
Debt Instrument [Line Items]
Unamortized discount on notes payable	$ (297,000)
Notes payable	9,703,000
Secured Debt | Oxford Finance LLC and Silicon Valley Bank
Debt Instrument [Line Items]
2,017	3,839,000
2,018	4,442,000
2,019	3,261,000
Total future minimum payments	11,542,000
Interest expense and other	1,542,000
Notes payable, gross	$ 10,000,000	$ 10,000,000

Debt (Warrants) (Details)

Debt (Warrants) (Details) - $ / shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Class of Warrant or Right [Line Items]
Class of warrant or right, exercised	22,265	1,586
Common Stock
Class of Warrant or Right [Line Items]
Exercise price of warrants (usd per share)	$ 0.67	$ 0.67
Outstanding warrants (shares)	1,003,984	1,026,249
Common Stock | September 2010 Warrants
Class of Warrant or Right [Line Items]
Exercise price of warrants (usd per share)	$ 160.44
Outstanding warrants (shares)	3,240	3,240
Common Stock | January 2012 Warrants
Class of Warrant or Right [Line Items]
Exercise price of warrants (usd per share)	$ 44.04
Outstanding warrants (shares)	13,623	13,623
Common Stock | March 2012 Warrants
Class of Warrant or Right [Line Items]
Outstanding warrants (shares)	13,256	24,388
Common Stock | June 2012 Warrants
Class of Warrant or Right [Line Items]
Exercise price of warrants (usd per share)	$ 0.67
Outstanding warrants (shares)	36,583	36,583
Common Stock | October 2012 Warrants
Class of Warrant or Right [Line Items]
Exercise price of warrants (usd per share)	$ 0.67
Outstanding warrants (shares)	51,425	62,558
Common Stock | November 2013 Warrants
Class of Warrant or Right [Line Items]
Exercise price of warrants (usd per share)	$ 7.66
Outstanding warrants (shares)	788,177	788,177
Common Stock | July 2015 Warrant
Class of Warrant or Right [Line Items]
Exercise price of warrants (usd per share)	$ 4.095
Outstanding warrants (shares)	97,680	97,680

Stockholders' Equity (Common St

Stockholders' Equity (Common Stock) (Details) - USD ($)	Jul. 10, 2014	Nov. 08, 2013	Apr. 23, 2013	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Jul. 30, 2015	May 15, 2015
Common Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Shares issued, value				$ 7,144,000	$ 3,455,000	$ 23,384,000
Common Stock
Common Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Shares issued (shares)		3,940,887	3,317,976
Shares issued, value		$ 28,000,000
Share price (usd per share)			$ 6.0264
Issuance costs charged to APIC		$ 1,500,000	$ 26,000
Proceeds from issuance, net of issuance costs			$ 20,000,000
Warrant
Common Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Share price (usd per share)							$ 3.84
Warrant | Common Stock
Common Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Shares issued (shares)		788,177
IPO | Common Stock
Common Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Shares issued (shares)	4,200,000
Issuance costs charged to APIC	$ 1,800,000
Proceeds from issuance of common stock	$ 25,200,000
Cowen
Common Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Proceeds from issuance, net of issuance costs				$ 7,140,000	$ 3,500,000
Cowen | Common Stock
Common Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Shares issued (shares)				2,865,391	946,497
Share price (usd per share)					$ 3.95
Average price of share, sale of stock (usd per share)				$ 2.61
Cowen | At the Market Issuance Sales Agreement
Common Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Maximum amount to be sold								$ 25,000,000
Common Stock, Value, Available for Sale in Future				$ 13,800,000

Stock Based Compensation (Stock

Stock Based Compensation (Stock Option Activity) (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Shares available for grant under stock option plans (shares)	1,176,304	1,299,301	342,210
Stock options granted (shares)	(2,341,350)	(707,500)
Stock options cancelled (shares)	818,353	364,591
Additional shares authorized	1,400,000	1,300,000
Stock Options Outstanding
Beginning balance, options (shares)	2,429,511	2,086,602
Stock options granted (shares)	2,341,350	707,500
Stock options exercised (shares)	(23,938)	0
Stock options canceled (shares)	(818,353)	(364,591)
Ending balance, options (shares)	3,928,570	2,429,511	2,086,602
Stock options vested and expected to vest (shares)	3,654,294
Stock options exercisable (shares)	1,639,838
Weighted-average Exercise Price Per Share
Weighted-average exercise price, options outstanding (usd per share)	$ 7	$ 8.01
Grants in period (usd per share)	2.67	3.73
Exercises in period (usd per share)	1.09	0
Cancelled in period (usd per share)	5.80	6.44
Weighted-average exercise price, options outstanding (usd per share)	4.71	$ 7	$ 8.01
Weighted-average exercise price, vested and expected to vest (usd per share)	4.85
Weighted-average exercise price, options vested and exercisable (usd per share)	$ 6.79
Weighted-average remaining contractual life, options outstanding (in years)	7 years 8 months 58 days	8 years 3 days	8 years 7 months 17 days
Weighted-average remaining contractual life, options vested and expected to vest (in years)	7 years 8 months 19 days
Weighted-average remaining contractual life, options exercisable (in years)	6 years 4 days
Aggregate Intrinsic value, options outstanding	$ 119	$ 287	$ 871
Aggregate Intrinsic value, vested and expected to vest	119
Aggregate Intrinsic value, options exercisable	$ 119

Stock Based Compensation (Sto46

Stock Based Compensation (Stock-based compensation expense) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 4,063	$ 3,977	$ 4,686
Research and Development
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	672	648	1,595
General and Administrative
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 3,391	$ 3,329	$ 3,091

Stock Based Compensation (Valua

Stock Based Compensation (Valuation Assumptions) (Details) - $ / shares	9 Months Ended	12 Months Ended
	Sep. 30, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Stock Options
Fair Value Assumptions and Methodology [Abstract]
Expected dividend yield (in percentage)		0.00%	0.00%	0.00%
Risk free interest rate, minimum (in percentage)		0.59%	1.52%	1.74%
Risk free interest rate, maximum (in percentage)		2.20%	2.08%	2.01%
Expected volatility, minimum (in percentage)		73.00%	76.00%	95.00%
Expected volatility, maximum (in percentage)		94.00%	92.00%	102.00%
Stock Options | Minimum
Fair Value Assumptions and Methodology [Abstract]
Expected term (in years)		11 months 12 days	4 years 11 months 27 days	6 years 29 days
Stock Options | Maximum
Fair Value Assumptions and Methodology [Abstract]
Expected term (in years)		8 years 15 days	8 years 22 days	6 years 7 months 13 days
Vest On Market Condition | Non Qualified Stock Option
Fair Value Assumptions and Methodology [Abstract]
Expected dividend yield (in percentage)	0.00%
Risk free interest rate, minimum (in percentage)		1.82%
Risk free interest rate, maximum (in percentage)		2.05%
Expected volatility, minimum (in percentage)		77.00%
Expected volatility, maximum (in percentage)		89.00%
Vest On Market Condition | Non Qualified Stock Option | Minimum
Fair Value Assumptions and Methodology [Abstract]
Expected term (in years)		6 years 7 days
Weighted-average fair value per share (in usd per share)		$ 1.33
Vest On Market Condition | Non Qualified Stock Option | Maximum
Fair Value Assumptions and Methodology [Abstract]
Expected term (in years)		8 years
Weighted-average fair value per share (in usd per share)		$ 1.42

Stock Based Compensation (Addit

Stock Based Compensation (Additional Information) (Details) - USD ($) $ / shares in Units, $ in Thousands	Jan. 06, 2016	Jun. 30, 2012	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Apr. 30, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for grant under stock option plans (in shares)			1,176,304	1,299,301	342,210
Expiration period (in years)			10 years
Total estimate grate date fair value of stock options vested			$ 3,800	$ 4,100	$ 4,100
Aggregate intrinsic value of options exercised					2,700
Stock-based compensation expense			$ 4,063	$ 3,977	$ 4,686
Shares issued in period (in shares)			2,341,350	707,500
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting term (in years)			1 year
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting term (in years)			4 years
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation costs not yet recognized			$ 5,500
Period for recognition			2 years 4 months 23 days
Stock Options | Executive Officer | Options Vesting Monthly Over A Year
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage (in percentage)		50.00%
Stock Options | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)			11 months 12 days	4 years 11 months 27 days	6 years 29 days
Stock Options | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)			8 years 15 days	8 years 22 days	6 years 7 months 13 days
Non Qualified Stock Option | Vest On Market Condition
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting term (in years)	48 months
Expiration period (in years)	10 years
Stock-based compensation expense			$ 200
Shares issued in period (in shares)	206,625
Minimum stock price for the options to vest	$ 6
Number of consecutive trading days	20 days
Non Qualified Stock Option | Minimum | Vest On Market Condition
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)			6 years 7 days
Non Qualified Stock Option | Maximum | Vest On Market Condition
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)			8 years
2011 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized for issuance (in shares)						5,002,328

Income Taxes (Geographical Brea

Income Taxes (Geographical Breakdown of Consolidated Income) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
United States	$ (26,895)	$ (26,749)	$ (24,624)

Income Taxes (Rate Reconciliati

Income Taxes (Rate Reconciliation) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Federal statutory tax rate	34.00%	34.00%
Income tax benefit at statutory rate	$ (9,144)	$ (9,094)	$ (8,372)
State income tax, net of federal benefit	54	693	(4,180)
Orphan drug expenses	998	817	1,045
Stock-based compensation	488	54	(45)
Other permanent items	10	35	98
Tax credits	(2,162)	(1,769)	(3,156)
Change in valuation allowance	9,756	9,264	14,610
Provision for income taxes	$ 0	$ 0	$ 0

Income Taxes (Deferred Tax Asse

Income Taxes (Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Net operating loss carryforwards	$ 49,635	$ 42,754
Tax credit carryforwards	8,932	7,141
Stock-based compensation	4,164	3,162
Other	127	45
Deferred tax assets before valuation allowance	62,858	53,102
Valuation allowance	(62,858)	(53,102)
Deferred tax assets:	$ 0	$ 0

Income Taxes (Unrecognized Tax

Income Taxes (Unrecognized Tax Benefits) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Beginning balance	$ 4,761	$ 3,773	$ 1,840
Increases in prior period positions	0	8	647
Increases in current period positions	1,194	980	1,286
Ending balance	$ 5,955	$ 4,761	$ 3,773

Income Taxes (Net Operating Los

Income Taxes (Net Operating Loss Carryforwards) (Details) $ in Thousands	Dec. 31, 2016USD ($)
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	$ 300
Federal
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	131,600
State | North Carolina
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	5,400
State | California
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	63,100
Orphan Drug Credit | Federal
Operating Loss Carryforwards [Line Items]
Tax credit carryforward, amount	10,700
Research Tax Credit Carryforward | Federal
Operating Loss Carryforwards [Line Items]
Tax credit carryforward, amount	2,500
Research Tax Credit Carryforward | State | North Carolina
Operating Loss Carryforwards [Line Items]
Tax credit carryforward, amount	200
Research Tax Credit Carryforward | State | California
Operating Loss Carryforwards [Line Items]
Tax credit carryforward, amount	$ 2,500

Retirement Savings Plan (Detail

Retirement Savings Plan (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Defined Contribution Plan Disclosure [Line Items]
Employer contribution amount	$ 0.1	$ 0.1	$ 0.1
401(k) Plan
Defined Contribution Plan Disclosure [Line Items]
Employer matching contribution percentage	3.00%

Commitments and Contingencies55

Commitments and Contingencies (Details) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Nov. 30, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Purchase commitment	$ 1,300
Payments to suppliers		$ 400
Cancellation fees		800
Rent expense		400	$ 300	$ 200
Future Minimum Payments Due by Fiscal Year Maturity [Abstract]
2,017		361
2,018		49
2019 and beyond		8
Total future minimum lease payments for operating leases		$ 418

Subsequent Event (Details)

Subsequent Event (Details) - Subsequent Event $ / shares in Units, $ in Millions	2 Months Ended
	Mar. 14, 2017USD ($)$ / sharesshares
Subsequent Event [Line Items]
Issuance of common stock, net of issuance cost, shares | shares	1,835,425
Average price of share, sale of stock (usd per share) | $ / shares	$ 1.57
Proceeds from issuance of common stock | $	$ 2.8

Summary of Operations by Quar57

Summary of Operations by Quarter (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Revenues	$ 512	$ 38	$ 26	$ 33	$ 24	$ 35	$ 43	$ 31
Operating expenses	5,408	6,901	6,879	7,301	6,836	6,648	6,290	6,695	$ 26,489	$ 26,469	$ 25,019
Net loss from continuing operations					(7,084)	(6,793)	(6,221)	(6,651)	(26,895)	(26,749)	(24,624)
Net loss	$ (5,153)	$ (7,125)	$ (7,103)	$ (7,514)	$ (7,076)	$ (6,574)	$ (6,221)	$ (6,651)	$ (26,895)	$ (26,522)	$ (23,425)
Net loss per share from continuing operations, basic and diluted (in dollars per share)					$ (0.34)	$ (0.34)	$ (0.31)	$ (0.34)	$ (1.22)	$ (1.33)	$ (1.41)
Net loss per share, basic and diluted (in dollars per share)	$ (0.22)	$ (0.32)	$ (0.33)	$ (0.36)	$ (0.34)	$ (0.33)	$ (0.31)	$ (0.34)	$ (1.22)	$ (1.32)	$ (1.34)
Weighted average number of shares used to compute net loss per share of common stock, basic and diluted (shares)	23,223,569	22,096,610	21,552,089	20,943,966	20,556,822	20,183,939	19,772,345	19,747,362	21,957,917	20,067,660	17,525,187