Trevena (TRVN) 10-Q 3 May 18 2018 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2018	Apr. 27, 2018
Document and Entity Information
Entity Registrant Name	TREVENA INC
Entity Central Index Key	1,429,560
Document Type	10-Q
Document Period End Date	Mar. 31, 2018
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding (in shares)		67,968,713
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q1

Balance Sheets

Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 18,146	$ 16,557
Marketable securities	43,445	49,543
Prepaid expenses and other current assets	1,847	1,393
Total current assets	63,438	67,493
Restricted cash	1,413	1,413
Property and equipment, net	3,779	3,805
Intangible asset, net	11	11
Total assets	68,641	72,722
Current liabilities:
Accounts payable	1,387	1,424
Accrued expenses and other current liabilities	1,519	4,303
Current portion of loans payable, net	12,460	12,425
Deferred rent	63	61
Total current liabilities	15,429	18,213
Loans payable, net	12,595	15,725
Capital leases, net of current portion	28	31
Deferred rent, net of current portion	2,992	3,006
Warrant liability	10	10
Other long term liabilities	1,270	1,104
Total liabilities	32,324	38,089
Commitments and contingencies (Note 6)
Stockholders’ equity:
Common stock—$0.001 par value; 100,000,000 shares authorized, 67,603,736 and 62,310,795 shares issued and outstanding at March 31, 2018 and December 31, 2017, respectively	68	62
Preferred stock—$0.001 par value; 5,000,000 shares authorized, none issued or outstanding at March 31, 2018 and December 31, 2017
Additional paid-in capital	402,806	392,103
Accumulated deficit	(366,511)	(357,490)
Accumulated other comprehensive loss	(46)	(42)
Total stockholders’ equity	36,317	34,633
Total liabilities and stockholders’ equity	$ 68,641	$ 72,722

Balance Sheets (Parenthetical)

Balance Sheets (Parenthetical) - $ / shares	Mar. 31, 2018	Dec. 31, 2017
Balance Sheets
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	100,000,000	100,000,000
Common stock, shares issued (in shares)	67,603,736	62,310,795
Common stock, shares outstanding (in shares)	67,603,736	62,310,795
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized (in shares)	5,000,000	5,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0

Statements of Operations and Co

Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Operating expenses:
General and administrative	$ 5,072	$ 4,879
Research and development	4,598	16,096
Restructuring charges	23
Total operating expenses	9,693	20,975
Loss from operations	(9,693)	(20,975)
Other income (expense):
Change in fair value of warrant liability		35
Net gain on asset disposals	223
Miscellaneous income	928	628
Interest income	199	174
Interest expense	(678)	(576)
Total other income	672	261
Net loss attributable to common stockholders	(9,021)	(20,714)
Other comprehensive loss, net:
Unrealized loss on marketable securities	(4)	(51)
Other comprehensive loss	(4)	(51)
Comprehensive loss	$ (9,025)	$ (20,765)
Per share information:
Net loss per share of common stock, basic and diluted (in dollars per share)	$ (0.14)	$ (0.36)
Weighted average common shares outstanding, basic and diluted (in shares)	64,562,236	56,894,672

Statement of Stockholders_ Equi

Statement of Stockholders’ Equity (Unaudited) - 3 months ended Mar. 31, 2018 - USD ($) $ in Thousands	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Income (Loss)	Total
Balance (in shares) at Dec. 31, 2017	62,310,795				62,310,795
Balance at Dec. 31, 2017	$ 62	$ 392,103	$ (357,490)	$ (42)	$ 34,633
Increase (Decrease) in Stockholders' Equity
Stock-based compensation expense		1,498			1,498
Exercise of stock options		57			$ 57
Exercise of stock options (in shares)	88,048				88,048
Issuance of common stock, net of issuance costs	$ 6	9,148			$ 9,154
Issuance of common stock, net of issuance costs (in shares)	5,204,893
Unrealized loss on marketable securities				(4)	(4)
Net loss			(9,021)		$ (9,021)
Balance (in shares) at Mar. 31, 2018	67,603,736				67,603,736
Balance at Mar. 31, 2018	$ 68	$ 402,806	$ (366,511)	$ (46)	$ 36,317

Statements of Cash Flows (Unaud

Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Operating activities:
Net loss	$ (9,021)	$ (20,714)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	171	79
Stock-based compensation	1,498	1,795
Noncash interest expense on loans	237	274
Revaluation of warrant liability		(35)
Amortization (accretion) of bond premium (discount) on marketable securities	(5)	182
Changes in operating assets and liabilities:
Prepaid expenses and other assets	(454)	(1,142)
Accounts payable, accrued expenses and other liabilities	(2,832)	(9,891)
Net cash used in operating activities	(10,406)	(29,452)
Investing activities:
Purchases of property and equipment	(144)	(116)
Maturities of marketable securities	16,500	21,958
Purchases of marketable securities	(10,402)	(15,108)
Net cash provided by investing activities	5,954	6,734
Financing activities:
Proceeds from exercise of common stock options	57	355
Proceeds from issuance of common stock, net	9,154	6,833
Capital lease payments	(3)	(2)
Proceeds from loans payable, net		9,921
Repayments of loans payable, net	(3,167)
Net cash provided by financing activities	6,041	17,107
Net increase (decrease) in cash and cash equivalents	1,589	(5,611)
Cash, cash equivalents and restricted cash—beginning of period	17,970	25,459
Cash, cash equivalents and restricted cash—end of period	19,559	19,848
Supplemental disclosure of cash flow information:
Cash paid for interest	$ 464	304
Fair value of common stock warrants issued		$ 184

Organization and Description of

Organization and Description of the Business	3 Months Ended
	Mar. 31, 2018
Organization and Description of the Business
Organization and Description of the Business	1. Organization and Description of the Business Trevena, Inc., or the Company, was incorporated in Delaware as Parallax Therapeutics, Inc. on November 9, 2007. The Company began operations in December 2007, and its name was changed to Trevena, Inc. on January 3, 2008. The Company is a biopharmaceutical company developing innovative therapies based on breakthrough science to benefit patients and healthcare providers confronting serious medical conditions. The Company operates in one segment and has its principal office in Chesterbrook, Pennsylvania. Since commencing operations in 2007, the Company has devoted substantially all of its financial resources and efforts to research and development, including preclinical studies and clinical trials. The Company has never been profitable and has not yet commenced commercial operations. In January 2018, the United States Food and Drug Administration, or FDA, accepted the new drug application, or NDA, submission for oliceridine, the Company's lead product candidate. The FDA also indicated that the Prescription Drug User Fee Act, or PDUFA, review date for the oliceridine NDA is November 2, 2018 and that it plans to hold an advisory committee meeting to discuss the NDA. If oliceridine ultimately receives regulatory approval, the Company plans to commercialize it in the United States, either on its own or with a commercial partner, for use in acute care settings such as hospitals and ambulatory surgery centers; outside the United States, the Company plans to commercialize oliceridine in certain countries with commercial partners. Since the Company’s inception, the Company has incurred losses and negative cash flows from operations. At March 31, 2018, the Company had an accumulated deficit of $366.5 million. The Company’s net loss was $9.0 million and $20.7 million for the three months ended March 31, 2018 and 2017, respectively. The Company expects its cash and cash equivalents of $18.1 million and marketable securities of $43.4 million as of March 31, 2018, together with interest thereon, as well as proceeds from the sale of shares of common stock under the Company’s at the market, or ATM, sales agreement with Cowen and Company, LLC, or Cowen, and from ex-U.S. licensing activities between March 31, 2018 and the date of this filing, to be sufficient to fund its operating expenses and capital expenditure requirements for at least twelve months following the date of this filing.

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2018
Summary of Significant Accounting Policies
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Basis of Presentation The accompanying financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America, or GAAP. Any reference in these notes to applicable guidance is meant to refer to the authoritative United States generally accepted accounting principles as found in the Accounting Standards Codification, or ASC, and Accounting Standards Update, or ASU, of the Financial Accounting Standards Board, or FASB. The Company’s functional currency is the U.S. dollar. The financial statements include all normal and recurring adjustments that are considered necessary for the fair presentation of the Company’s balance sheet as of March 31, 2018, its results of operations and its comprehensive loss for the three months ended March 31, 2018 and 2017, its statement of stockholders’ equity for the period from January 1, 2018 to March 31, 2018, and its cash flows for the three months ended March 31, 2018 and 2017. The information included in this Quarterly Report on Form 10‑Q should be read in conjunction with the financial statements and accompanying notes included in the Company’s most recent Annual Report on Form 10‑K for the year ended December 31, 2017. Since the date of those financial statements, there have been no changes to the Company’s significant accounting policies. The financial data and other information disclosed in these notes related to the three ended March 31, 2018 and 2017 are not necessarily indicative of the results to be expected for the year ending December 31, 2018, any other interim periods, or any future year or period. Recently Adopted Accounting Standards In December 2017, the SEC staff issued Staff Accounting Bulletin No. 118, or SAB 118, which provides guidance on accounting for the tax effects of the Tax Act of 2017, of the Tax Act. SAB 118 was issued to address the application of U.S. GAAP in situations when a registrant does not have the necessary information available, prepared, or analyzed (including computations) in reasonable detail to complete the accounting for certain income tax effects of the Act and allows the Company to record provisional amounts during a measurement period not to extend beyond one year of the Tax Act enactment date. The Company was able to reasonably estimate certain effects of the Tax Act as of December 31, 2017 and has not changed the preliminary estimates as of March 31, 2018. In May 2017, the FASB issued ASU No. 2017-09, Stock Compensation - Scope of Modification Accounting, which amends the scope of modification accounting for share-based payment arrangements. The amendment provides guidance about which changes to the terms or conditions of a share-based payment award require an entity to apply modification accounting. The new standard is effective for fiscal years beginning after December 15, 2017. The adoption of this standard did not have an impact on the Company’s consolidated financial statements. In August 2016, the FASB issued ASU 2016-15, Statement of Cash Flows (Topic 230), to clarify how certain cash receipts and payments should be presented in the statement of cash flows. The standard is effective for annual periods beginning after December 15, 2017 and interim periods within that reporting period. The adoption of this standard did not have an impact on the Company’s consolidated financial statements. In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers . ASU 2014-09 is a comprehensive new revenue recognition model requiring a company to recognize revenue to depict the transfer of goods or services to a customer in an amount reflecting the consideration it expects to receive in exchange for those goods or services. Additionally, in March 2016, the FASB issued ASU 2016-08, Revenue from Contracts with Customers, Principal versus Agent Considerations . ASU 2016-08 amends the principal versus agent guidance in ASU 2014-09 to clarify how an entity should identify the unit of accounting for the principal versus agent evaluation and how it should apply the control principal to certain types of arrangements. The effective date for both standards is January 1, 2018. The Company adopted these standards on January 1, 2018 and elected the modified retrospective transition method, meaning the cumulative effect of applying the new guidance, if any, was recognized at that date as an adjustment to the opening accumulated deficit balance. Since the Company does not have any open contracts with customers as of January 1, 2018 and did not enter into any new contracts with customers during the three months ended March 31, 2018, the adoption of this standard did not have an impact on the Company's financial statements. Recent Accounting Standards Not Yet Adopted In February 2018, the FASB issued ASU 2018-02, Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income , which provides the option to reclassify stranded tax effects within accumulated other comprehensive income to retained earnings. This option would be available in each period in which the effect of the change in the U.S. federal corporate income tax rate in the Tax Cuts and Jobs Act (or a portion thereof) is recorded. This is effective for the Company beginning after December 15, 2018, with early adoption permitted. These amendments should be applied in the period of adoption or retrospectively to each period in which the effect of the change in the U.S federal corporate income tax rate in the Tax Cuts and Jobs Act is recognized. The Company is evaluating the effect this standard will have on its financial statements and related disclosures. In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842 ), which requires lessees to record most leases on their balance sheets and disclose key information about leasing arrangements in an effort to increase transparency and comparability among organizations. The standard is effective for annual periods beginning after December 15, 2018 and interim periods within that reporting period. Early adoption is permitted. The Company is evaluating the effect this standard will have on its financial statements and related disclosures.

Fair Value of Financial Instrum

Fair Value of Financial Instruments	3 Months Ended
	Mar. 31, 2018
Fair Value of Financial Instruments
Fair Value of Financial Instruments	3. Fair Value of Financial Instruments ASC Topic 820, Fair Value Measurement, establishes a fair value hierarchy for instruments measured at fair value that distinguishes between assumptions based on market data (observable inputs) and the Company’s own assumptions (unobservable inputs). Observable inputs are inputs that market participants would use in pricing the asset or liability based on market data obtained from sources independent of the Company. Unobservable inputs are inputs that reflect the Company’s assumptions about the inputs that market participants would use in pricing the asset or liability, and are developed based on the best information available in the circumstances. ASC 820 identifies fair value as the exchange price, or exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As a basis for considering market participant assumptions in fair value measurements, ASC 820 establishes a three-tier fair value hierarchy that distinguishes among the following: · Level 1‑Valuations based on unadjusted quoted prices in active markets for identical assets or liabilities that the Company has the ability to access. · Level 2‑Valuations based on quoted prices for similar assets or liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are not active and models for which all significant inputs are observable, either directly or indirectly. · Level 3‑Valuations based on inputs that are unobservable and significant to the overall fair value measurement. To the extent that the valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized in Level 3. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. Cash, Cash Equivalents and Marketable Securities The following table presents fair value of the Company’s cash, cash equivalents, and marketable securities as of March 31, 2018 and December 31, 2017 (in thousands): March 31, 2018 Adjusted Unrealized Unrealized Cash and Cash Restricted Marketable Cost Gains Loss Fair Value Equivalents Cash Securities Cash $ 7,052 $ — $ — $ 7,052 $ 5,639 $ 1,413 $ — Level 1 (1): Money market funds 12,507 — — 12,507 12,507 — — U.S. treasury securities 1,994 — (2) 1,992 — — 1,992 Subtotal 14,501 — (2) 14,499 12,507 — 1,992 Level 2 (2): U.S. government agency securities 41,497 — (44) 41,453 — — 41,453 Total $ 63,050 $ — $ (46) $ 63,004 $ 18,146 $ 1,413 $ 43,445 December 31, 2017 Adjusted Unrealized Unrealized Cash and Cash Restricted Marketable Cost Gains Losses Fair Value Equivalents Cash Securities Cash $ 6,783 $ — $ — $ 6,783 $ 5,370 $ 1,413 $ — Level 1 (1): Money market funds 11,187 — — 11,187 11,187 — — U.S. treasury securities 1,991 — — 1,991 — — 1,991 Subtotal 13,178 — — 13,178 11,187 — 1,991 Level 2 (2): U.S. government agency securities 47,594 — (42) 47,552 — — 47,552 Total $ 67,555 $ — $ (42) $ 67,513 $ 16,557 $ 1,413 $ 49,543 (1) The fair value of Level 1 securities is estimated based on quoted prices in active markets for identical assets or liabilities. (2) The fair value of Level 2 securities is estimated based on observable inputs other than quoted prices in active markets for identical assets and liabilities, quoted prices for identical or similar assets or liabilities in inactive markets, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. The Company classifies investments available to fund current operations as current assets on its balance sheets. As of March 31, 2018, the Company did not hold any investment securities exceeding a one-year maturity. Unrealized gains and losses on marketable securities are recorded as a separate component of accumulated other comprehensive income (loss) included in stockholders’ equity. Realized gains (losses) are included in interest income (expense) in the statement of operations and comprehensive income (loss) on a specific identification basis. The Company did not record any realized gains or losses during the three months ended March 31, 2018 and 2017. To date, the Company has not recorded any impairment charges on marketable securities related to other-than-temporary declines in market value. The Company recognizes transfers between levels of the fair value hierarchy as of the end of the reporting period. There were no transfers between Level 2 and Level 3 during the three months ended March 31, 2018 or the year ended December 31, 2017.

Loans Payable

Loans Payable	3 Months Ended
	Mar. 31, 2018
Loans Payable
Loans Payable	4. Loans Payable In September 2014, the Company entered into a loan and security agreement with Oxford Finance LLC and Pacific Western Bank (formerly Square 1Bank) (together, the lenders), pursuant to which the lenders agreed to lend the Company up to $35.0 million in a three-tranche series of term loans (Term Loans A, B, and C). Upon initially entering into the agreement, the Company borrowed $2.0 million under Term Loan A. In April 2015, the Company amended the agreement with the lenders to change the draw period for Term Loan B. In December 2015, the Company further amended the agreement with the lenders to, among other things, change the draw period for Term Loan C, modify the interest only period, and modify the maturity date of the loan. In December 2015, the Company borrowed the Term Loan B tranche of $16.5 million. The Company’s ability to draw an additional $16.5 million under Term Loan C was subject to the satisfaction of one or more specified triggers related to the results of the Company’s Phase 2b clinical trial of TRV027, which were announced in May 2016. Although those triggers were not attained, in December 2016, the Company and the lenders modified the terms and conditions under which the Company could exercise an option to draw $10.0 million of Term Loan C. In March 2017, the Company borrowed the Term Loan C tranche of $10.0 million. Borrowings under Term Loans A and B accrue interest at a fixed rate of 6.50% per annum. Borrowings under Term Loan C accrue interest at a fixed rate of 6.98% per annum. The Company was required to make payments of interest only on borrowings under the loan agreement on a monthly basis through and including January 1, 2018. Payments of principal in equal monthly installments and accrued interest began January 1, 2018 and will continue to be due until the loan matures on March 1, 2020. Upon the last payment date of the amounts borrowed under the agreement, the Company will be required to pay a final payment fee equal to 6.6% of the aggregate amounts borrowed, which is recorded as interest expense over the term of the loans payable. In addition, if the Company repays Term Loan A, Term Loan B, or Term Loan C prior to the applicable maturity date, it will pay the lenders a prepayment fee of 1.0% of each of Term Loans A and B, and 2.0% of Term Loan C, if the prepayment occurs on or between April 1, 2018 and March 31, 2019, and 1.0% of Term Loan C, if the prepayment occurs on or after April 1, 2019. The Company’s obligations under the loan and security agreement are secured by a first priority security interest in substantially all of the assets of the Company, including the Company’s cash, cash equivalents, and marketable securities but excluding the Company’s intellectual property (together, the collateral). The Company has agreed not to pledge or otherwise encumber its intellectual property, other than through grants of certain permitted non-exclusive or exclusive licenses or other conveyances of its intellectual property. The loan and security agreement includes affirmative and restrictive covenants, including: (a) financial reporting requirements; (b) limitations on the incurrence of indebtedness; (c) limitations on liens; (d) limitations on certain merger and acquisition transactions; (e) limitations on dispositions of certain assets; (f) limitations on fundamental corporate changes (including changes in control); (g) limitations on investments; (h) limitations on payments and distributions and (i) other covenants. The agreement also contains certain events of default, including for payment defaults, breaches of covenants, a material adverse change in the Company’s business, operations or condition (financial or otherwise), a material impairment in the value of the collateral or in the prospect of repayment of the Company’s obligations to the lender, certain levies, attachments and other restraints on the Company’s business, insolvency, defaults under other agreements and misrepresentations. Upon an event of default, the lenders have the right to foreclose upon the available collateral, including the Company’s existing cash and cash equivalents and marketable securities. In connection with entering into the agreement, the Company issued to the lenders and the placement agent warrants to purchase an aggregate of 7,678 shares of Trevena’s common stock, of which 5,728 shares remain outstanding as of March 31, 2018. These detachable warrant instruments have qualified for equity classification and have been allocated upon the relative fair value of the base instrument and the warrants, according to the guidance of ASC 470-20-25-2. These warrants are exercisable immediately and have an exercise price of $5.8610 per share. The warrants may be exercised on a cashless basis and will terminate on the earlier of September 19, 2024 or the closing of a merger or consolidation transaction in which the Company is not the surviving entity. In connection with the draw of Term Loan B, the Company issued to the lenders and the placement agent additional warrants to purchase an aggregate of 34,961 shares of Trevena common stock, all of which remain outstanding at March 31, 2018. These warrants have substantially the same terms as those noted above, have an exercise price of $10.6190 per share and an expiration date of December 23, 2025. In connection with draw of Term Loan C, the Company issued to the lenders and placement agent additional warrants to purchase an aggregate of 62,241 shares of our common stock, all of which remain outstanding at March 31, 2018. These warrants have substantially the same terms as those noted above, and have an exercise price of $3.6150 per share and an expiration date of March 31, 2027. As of March 31, 2018, borrowings of $25.3 million attributable to Term Loans A, B, and C remain outstanding. Interest expense of $0.4 million and $0.3 million was recorded during the three months ended March 31, 2018 and 2017, respectively. The Company incurred lender and third party costs of $1.0 million related to the issuance of our term loans. Per ASU 2015‑3, Interest-Imputation of Interest , debt discount and debt issuance costs are to be presented as a contra-liability to the debt on the balance sheet. These costs will be amortized to interest expense over the life of the loans using the effective interest method. Immaterial amounts of debt discount and debt issuance cost were amortized to interest expense during the three months ended March 31, 2018 and 2017 respectively. The following table summarizes how the issuance of Term Loans A, B, and C are reflected on the balance sheet at March 31, 2018 and December 31, 2017 (in thousands): March 31, December 31, 2018 2017 Gross proceeds $ 25,333 $ 28,500 Debt discount and debt issuance costs (278) (350) Carrying value 25,055 28,150 Current portion of loans payable, net 12,460 12,425 Loans payable, net $ 12,595 $ 15,725

Stockholders' Equity

Stockholders' Equity	3 Months Ended
	Mar. 31, 2018
Other Comprehensive Loss
Stockholders' Equity	5. Stockholders’ Equity Equity Offerings On December 14, 2015, the Company entered into an at the market, or ATM, sales agreement with Cowen and Company, LLC, or Cowen, to offer and sell, from time to time at its sole discretion, shares of its common stock, par value $0.001 per share, having an aggregate offering price of up to $75.0 million through Cowen as its sales agent. Sales of the shares are deemed to be “at the market offerings”, as defined in Rule 415 under the Securities Act of 1933, as amended. The Company is required to pay Cowen a commission of up to three percent of the gross sales proceeds and has provided Cowen with customary indemnification rights. In the first quarter of 2018, the Company issued and sold 5,204,893 shares of common stock under this ATM facility at a weighted average price per share of $1.81. The net offering proceeds to the Company were approximately $9.2 million after deducting related expenses, including commissions. As of March 31, 2018, approximately $11.2 million of the $75.0 million remained available under the ATM facility. Equity Incentive Plans The Company utilizes equity incentive plans to grant various forms of stock options and restricted stock to eligible employees, directors and consultants to the Company. Under all of such plans, the amount, terms of grants and exercisability provisions are determined by the board of directors or its designee. The term of the options may be up to 10 years, and options are exercisable in cash or as otherwise determined by the board of directors. Vesting generally occurs over a period of not greater than 4 years. For performance-based stock awards, we recognize expense when achievement of the performance factor is probable, over the requisite service period. The estimated grant-date fair value of the Company’s stock-based awards is amortized ratably over the awards’ service periods. Stock-based compensation expense recognized was as follows (in thousands): Three Months Ended March 31, 2018 2017 Research and development $ 358 $ 707 General and administrative 1,140 1,088 Total stock-based compensation $ 1,498 $ 1,795 Options Outstanding Weighted Average Weighted Remaining Average Contractual Number of Exercise Term Shares Price (in years) Balance, December 31, 2017 8,624,223 $ 5.22 7.2 Granted 2,600,625 1.79 Exercised (88,048) 0.65 Forfeited/Cancelled (739,557) 5.14 Balance, March 31, 2018 10,397,243 $ 4.40 8.01 Vested or expected to vest at March 31, 2018 10,397,243 $ 4.40 8.01 Exercisable at March 31, 2018 4,186,575 $ 5.49 6.23 The intrinsic value of the options exercisable as of March 31, 2018 was $0.3 million, based on the Company’s closing stock price of $1.64 per share and a weighted average exercise price of $5.49 per share. At March 31, 2018, there was $13.7 million of total unrecognized compensation expense related to unvested options that will be recognized over the weighted average remaining period of 2.38 years. The Company uses the Black-Scholes option pricing model to estimate the fair value of stock options at the grant date. The Black-Scholes model requires the Company to make certain estimates and assumptions, including estimating the fair value of the Company’s common stock, assumptions related to the expected price volatility of the Company’s stock, the period during which the options will be outstanding, the rate of return on risk-free investments and the expected dividend yield for the Company’s common stock. The per-share weighted-average grant date fair value of the options granted to employees and directors during the three months ended March 31, 2018 and 2017 was estimated at $1.19 and $3.35 per share, respectively, on the date of grant using the Black-Scholes option pricing model with the following weighted-average assumptions: Three Months Ended March 31, 2018 2017 Expected term of options (in years) 5.8 6.3 Risk-free interest rate 2.7 % 2.1 % Expected volatility 76.0 % 75.7 % Dividend yield 0 % 0 % Shares Available for Future Grant At March 31, 2018, the Company has the following shares available to be granted under its equity incentive plans: Inducement 2013 Plan Plan Available at December 31, 2017 991,613 293,000 Authorized 2,492,431 — Granted (2,505,625) (95,000) Forfeited/Cancelled 687,057 52,500 Available at March 31, 2018 1,665,476 250,500 Shares Reserved for Future Issuance At March 31, 2018, the Company has reserved the following shares of common stock for issuance: Stock options outstanding under 2013 Plan 10,147,743 Shares available for future grant under 2013 Plan 1,665,476 Stock options outstanding under Inducement Plan 249,500 Shares available for future grant under Inducement Plan 250,500 Employee stock purchase plan 225,806 Warrants outstanding 123,091 Total shares of common stock reserved for future issuance 12,662,116

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2018
Commitments and Contingencies.
Commitments and Contingencies	6. Commitments and Contingencies Legal Proceedings The Company is not involved in any legal proceeding that it expects to have a material effect on its business, financial condition, results of operations and cash flows.

Net Loss Per Common Share

Net Loss Per Common Share	3 Months Ended
	Mar. 31, 2018
Net Loss Per Common Share
Net Loss Per Common Share	7. Net Loss Per Common Share The following table sets forth the computation of basic and diluted net loss per share for the periods indicated (in thousands, except share and per share data): Three Months Ended March 31, 2018 2017 Basic and diluted net loss per common share calculation: Net loss $ (9,021) $ (20,714) Net loss attributable to common stockholders $ (9,021) $ (20,714) Weighted average common shares outstanding 64,562,236 56,894,672 Net loss per share of common stock - basic and diluted $ (0.14) $ (0.36) The following outstanding securities at March 31, 2018 and 2017 have been excluded from the computation of diluted weighted shares outstanding, as they would have been anti-dilutive: March 31, 2018 2017 Options outstanding 10,397,243 8,461,435 Warrants 123,091 123,091 Total 10,520,334 8,584,526

Other Comprehensive Loss

Other Comprehensive Loss	3 Months Ended
	Mar. 31, 2018
Other Comprehensive Loss
Other Comprehensive Loss	8. Other Comprehensive Loss The following table presents changes in the components of accumulated other comprehensive loss (in thousands): Balance, December 31, 2017 $ (42) Net unrealized loss on marketable securities (4) Balance, March 31, 2018 $ (46) There were no reclassifications out of accumulated other comprehensive loss during the three months ended March 31, 2018 and 2017. There was no tax effect during the three months ended March 31, 2018 and 2017.

Restructuring Charges (Loss)

Restructuring Charges (Loss)	3 Months Ended
	Mar. 31, 2018
Restructuring Charges.
Restructuring Charges	9. Restructuring Charges On October 11, 2017, upon the approval of the Company's Board of Directors, the Company announced a restructuring and reduction in force of approximately 30% of the Company's workforce, or 21 employees. As part of this restructuring, the Company also halted its investment in early stage research. The Company incurred pre-tax restructuring charges of $1.8 million during the year ended December 31, 2017, primarily related to severance and personnel related costs in addition to lease termination payments. As of December 31, 2017, the Company’s restructuring liability totaled $1.1 million. During the three months ended March 31, 2018, the Company made severance payments totaling $0.7 million. As of March 31, 2018, the Company’s restructuring liability totals $0.4 million, which has been recorded within accrued expenses on the Company’s balance sheet.

Subsequent Events

Subsequent Events	3 Months Ended
	Mar. 31, 2018
Subsequent Events
Subsequent Events	10. Subsequent Events In April 2018 and May 2018, the Company announced that it had entered into exclusive licensing agreements for the development and commercialization of oliceridine in South Korea and China, respectively. Under the license in South Korea with Pharmbio Korea Inc., the Company received an upfront payment of $3.0 million, and will receive a commercial milestone, if approved in South Korea, and tiered royalties on product sales in South Korea ranging from high single digits to 20%. Under the license in China with Jiangsu Nhwa Pharmaceutical Co. Ltd., the Company will receive an upfront payment of $2.5 million, milestone payments of $3.0 million upon regulatory approval of oliceridine in each of the United States and China, up to $6.0 million of commercialization milestones, and a ten percent royalty on all net product sales in China.

Summary of Significant Accoun17

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2018
Summary of Significant Accounting Policies
Basis of Presentation	Basis of Presentation The accompanying financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America, or GAAP. Any reference in these notes to applicable guidance is meant to refer to the authoritative United States generally accepted accounting principles as found in the Accounting Standards Codification, or ASC, and Accounting Standards Update, or ASU, of the Financial Accounting Standards Board, or FASB. The Company’s functional currency is the U.S. dollar. The financial statements include all normal and recurring adjustments that are considered necessary for the fair presentation of the Company’s balance sheet as of March 31, 2018, its results of operations and its comprehensive loss for the three months ended March 31, 2018 and 2017, its statement of stockholders’ equity for the period from January 1, 2018 to March 31, 2018, and its cash flows for the three months ended March 31, 2018 and 2017. The information included in this Quarterly Report on Form 10‑Q should be read in conjunction with the financial statements and accompanying notes included in the Company’s most recent Annual Report on Form 10‑K for the year ended December 31, 2017. Since the date of those financial statements, there have been no changes to the Company’s significant accounting policies. The financial data and other information disclosed in these notes related to the three ended March 31, 2018 and 2017 are not necessarily indicative of the results to be expected for the year ending December 31, 2018, any other interim periods, or any future year or period.
Recent Accounting Standards Adopted and Not Yet Adopted	Recently Adopted Accounting Standards In December 2017, the SEC staff issued Staff Accounting Bulletin No. 118, or SAB 118, which provides guidance on accounting for the tax effects of the Tax Act of 2017, of the Tax Act. SAB 118 was issued to address the application of U.S. GAAP in situations when a registrant does not have the necessary information available, prepared, or analyzed (including computations) in reasonable detail to complete the accounting for certain income tax effects of the Act and allows the Company to record provisional amounts during a measurement period not to extend beyond one year of the Tax Act enactment date. The Company was able to reasonably estimate certain effects of the Tax Act as of December 31, 2017 and has not changed the preliminary estimates as of March 31, 2018. In May 2017, the FASB issued ASU No. 2017-09, Stock Compensation - Scope of Modification Accounting, which amends the scope of modification accounting for share-based payment arrangements. The amendment provides guidance about which changes to the terms or conditions of a share-based payment award require an entity to apply modification accounting. The new standard is effective for fiscal years beginning after December 15, 2017. The adoption of this standard did not have an impact on the Company’s consolidated financial statements. In August 2016, the FASB issued ASU 2016-15, Statement of Cash Flows (Topic 230), to clarify how certain cash receipts and payments should be presented in the statement of cash flows. The standard is effective for annual periods beginning after December 15, 2017 and interim periods within that reporting period. The adoption of this standard did not have an impact on the Company’s consolidated financial statements. In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers . ASU 2014-09 is a comprehensive new revenue recognition model requiring a company to recognize revenue to depict the transfer of goods or services to a customer in an amount reflecting the consideration it expects to receive in exchange for those goods or services. Additionally, in March 2016, the FASB issued ASU 2016-08, Revenue from Contracts with Customers, Principal versus Agent Considerations . ASU 2016-08 amends the principal versus agent guidance in ASU 2014-09 to clarify how an entity should identify the unit of accounting for the principal versus agent evaluation and how it should apply the control principal to certain types of arrangements. The effective date for both standards is January 1, 2018. The Company adopted these standards on January 1, 2018 and elected the modified retrospective transition method, meaning the cumulative effect of applying the new guidance, if any, was recognized at that date as an adjustment to the opening accumulated deficit balance. Since the Company does not have any open contracts with customers as of January 1, 2018 and did not enter into any new contracts with customers during the three months ended March 31, 2018, the adoption of this standard did not have an impact on the Company's financial statements. Recent Accounting Standards Not Yet Adopted In February 2018, the FASB issued ASU 2018-02, Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income , which provides the option to reclassify stranded tax effects within accumulated other comprehensive income to retained earnings. This option would be available in each period in which the effect of the change in the U.S. federal corporate income tax rate in the Tax Cuts and Jobs Act (or a portion thereof) is recorded. This is effective for the Company beginning after December 15, 2018, with early adoption permitted. These amendments should be applied in the period of adoption or retrospectively to each period in which the effect of the change in the U.S federal corporate income tax rate in the Tax Cuts and Jobs Act is recognized. The Company is evaluating the effect this standard will have on its financial statements and related disclosures. In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842 ), which requires lessees to record most leases on their balance sheets and disclose key information about leasing arrangements in an effort to increase transparency and comparability among organizations. The standard is effective for annual periods beginning after December 15, 2018 and interim periods within that reporting period. Early adoption is permitted. The Company is evaluating the effect this standard will have on its financial statements and related disclosures.

Fair Value of Financial Instr18

Fair Value of Financial Instruments (Tables)	3 Months Ended
	Mar. 31, 2018
Fair Value of Financial Instruments
Schedule of cash and available-for-sale securities’ adjusted cost, gross unrealized gains, gross unrealized losses and fair values by significant investment category	The following table presents fair value of the Company’s cash, cash equivalents, and marketable securities as of March 31, 2018 and December 31, 2017 (in thousands): March 31, 2018 Adjusted Unrealized Unrealized Cash and Cash Restricted Marketable Cost Gains Loss Fair Value Equivalents Cash Securities Cash $ 7,052 $ — $ — $ 7,052 $ 5,639 $ 1,413 $ — Level 1 (1): Money market funds 12,507 — — 12,507 12,507 — — U.S. treasury securities 1,994 — (2) 1,992 — — 1,992 Subtotal 14,501 — (2) 14,499 12,507 — 1,992 Level 2 (2): U.S. government agency securities 41,497 — (44) 41,453 — — 41,453 Total $ 63,050 $ — $ (46) $ 63,004 $ 18,146 $ 1,413 $ 43,445 December 31, 2017 Adjusted Unrealized Unrealized Cash and Cash Restricted Marketable Cost Gains Losses Fair Value Equivalents Cash Securities Cash $ 6,783 $ — $ — $ 6,783 $ 5,370 $ 1,413 $ — Level 1 (1): Money market funds 11,187 — — 11,187 11,187 — — U.S. treasury securities 1,991 — — 1,991 — — 1,991 Subtotal 13,178 — — 13,178 11,187 — 1,991 Level 2 (2): U.S. government agency securities 47,594 — (42) 47,552 — — 47,552 Total $ 67,555 $ — $ (42) $ 67,513 $ 16,557 $ 1,413 $ 49,543 (1) The fair value of Level 1 securities is estimated based on quoted prices in active markets for identical assets or liabilities. (2) The fair value of Level 2 securities is estimated based on observable inputs other than quoted prices in active markets for identical assets and liabilities, quoted prices for identical or similar assets or liabilities in inactive markets, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities.

Loans Payable (Tables)

Loans Payable (Tables)	3 Months Ended
	Mar. 31, 2018
Loans Payable
Schedule of loans reflected on the balance sheet	The following table summarizes how the issuance of Term Loans A, B, and C are reflected on the balance sheet at March 31, 2018 and December 31, 2017 (in thousands): March 31, December 31, 2018 2017 Gross proceeds $ 25,333 $ 28,500 Debt discount and debt issuance costs (278) (350) Carrying value 25,055 28,150 Current portion of loans payable, net 12,460 12,425 Loans payable, net $ 12,595 $ 15,725

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	3 Months Ended
	Mar. 31, 2018
Other Comprehensive Loss
Schedule of share-based compensation expense recognized	The estimated grant-date fair value of the Company’s stock-based awards is amortized ratably over the awards’ service periods. Stock-based compensation expense recognized was as follows (in thousands): Three Months Ended March 31, 2018 2017 Research and development $ 358 $ 707 General and administrative 1,140 1,088 Total stock-based compensation $ 1,498 $ 1,795
Summary of stock option activity	Options Outstanding Weighted Average Weighted Remaining Average Contractual Number of Exercise Term Shares Price (in years) Balance, December 31, 2017 8,624,223 $ 5.22 7.2 Granted 2,600,625 1.79 Exercised (88,048) 0.65 Forfeited/Cancelled (739,557) 5.14 Balance, March 31, 2018 10,397,243 $ 4.40 8.01 Vested or expected to vest at March 31, 2018 10,397,243 $ 4.40 8.01 Exercisable at March 31, 2018 4,186,575 $ 5.49 6.23
Schedule of weighted-average assumptions	Three Months Ended March 31, 2018 2017 Expected term of options (in years) 5.8 6.3 Risk-free interest rate 2.7 % 2.1 % Expected volatility 76.0 % 75.7 % Dividend yield 0 % 0 %
Schedule of shares available to be granted under equity incentive plans	At March 31, 2018, the Company has the following shares available to be granted under its equity incentive plans: Inducement 2013 Plan Plan Available at December 31, 2017 991,613 293,000 Authorized 2,492,431 — Granted (2,505,625) (95,000) Forfeited/Cancelled 687,057 52,500 Available at March 31, 2018 1,665,476 250,500
Schedule of shares of common stock reserved for issuance	At March 31, 2018, the Company has reserved the following shares of common stock for issuance: Stock options outstanding under 2013 Plan 10,147,743 Shares available for future grant under 2013 Plan 1,665,476 Stock options outstanding under Inducement Plan 249,500 Shares available for future grant under Inducement Plan 250,500 Employee stock purchase plan 225,806 Warrants outstanding 123,091 Total shares of common stock reserved for future issuance 12,662,116

Net Loss Per Common Share (Tabl

Net Loss Per Common Share (Tables)	3 Months Ended
	Mar. 31, 2018
Net Loss Per Common Share
Schedule of computation of basic and diluted net loss per share	The following table sets forth the computation of basic and diluted net loss per share for the periods indicated (in thousands, except share and per share data): Three Months Ended March 31, 2018 2017 Basic and diluted net loss per common share calculation: Net loss $ (9,021) $ (20,714) Net loss attributable to common stockholders $ (9,021) $ (20,714) Weighted average common shares outstanding 64,562,236 56,894,672 Net loss per share of common stock - basic and diluted $ (0.14) $ (0.36)
Schedule of outstanding securities excluded from the computation of diluted weighted shares outstanding as they would have been anti-dilutive	March 31, 2018 2017 Options outstanding 10,397,243 8,461,435 Warrants 123,091 123,091 Total 10,520,334 8,584,526

Other Comprehensive Loss (Table

Other Comprehensive Loss (Tables)	3 Months Ended
	Mar. 31, 2018
Other Comprehensive Loss
Schedule of accumulated other comprehensive loss, net of tax	The following table presents changes in the components of accumulated other comprehensive loss (in thousands): Balance, December 31, 2017 $ (42) Net unrealized loss on marketable securities (4) Balance, March 31, 2018 $ (46)

Organization and Description 23

Organization and Description of the Business (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2018USD ($)segment	Mar. 31, 2017USD ($)	Dec. 31, 2017USD ($)
Organization and Description of the Business
Number of operating segments | segment	1
Liquidity
Accumulated deficit	$ 366,511		$ 357,490
Net loss	9,021	$ 20,714
Cash and cash equivalents	18,146		16,557
Marketable securities	$ 43,445		$ 49,543

Fair Value of Financial Instr24

Fair Value of Financial Instruments - Hierarchy Table (Details) - USD ($)	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Fair value
Unrealized loss on marketable securities	$ (4,000)	$ (51,000)
Transfers Level 2 to 3 assets	0		$ 0
Transfers Level 3 to 2 assets	0		0
Transfers Level 2 to 3 liabilities	0		0
Transfers Level 3 to 2 liabilities	0		0
Fair Value
Fair value
Adjusted Cost	63,050,000		67,555,000
Unrealized Losses	(46,000)		(42,000)
Fair Value	63,004,000		67,513,000
Fair Value | Cash and Cash Equivalents
Fair value
Fair Value	18,146,000		16,557,000
Fair Value | Restricted cash
Fair value
Fair Value	1,413,000		1,413,000
Fair Value | Marketable Securities.
Fair value
Fair Value	43,445,000		49,543,000
Cash
Fair value
Adjusted Cost	7,052,000		6,783,000
Fair Value	7,052,000		6,783,000
Cash | Cash and Cash Equivalents
Fair value
Fair Value	5,639,000		5,370,000
Cash | Restricted cash
Fair value
Fair Value	1,413,000		1,413,000
Level 1
Fair value
Adjusted Cost	14,501,000		13,178,000
Unrealized Losses	(2,000)
Fair Value	14,499,000		13,178,000
Level 1 | Cash and Cash Equivalents
Fair value
Fair Value	12,507,000		11,187,000
Level 1 | Marketable Securities.
Fair value
Fair Value	1,992,000		1,991,000
Level 1 | Money market mutual funds
Fair value
Adjusted Cost	12,507,000		11,187,000
Fair Value	12,507,000		11,187,000
Level 1 | Money market mutual funds | Cash and Cash Equivalents
Fair value
Fair Value	12,507,000		11,187,000
Level 1 | US Treasury Securities
Fair value
Adjusted Cost	1,994,000		1,991,000
Unrealized Losses	(2,000)
Fair Value	1,992,000		1,991,000
Level 1 | US Treasury Securities | Marketable Securities.
Fair value
Fair Value	1,992,000		1,991,000
Level 2 | U.S. government agency securities
Fair value
Adjusted Cost	41,497,000		47,594,000
Unrealized Losses	(44,000)		(42,000)
Fair Value	41,453,000		47,552,000
Level 2 | U.S. government agency securities | Marketable Securities.
Fair value
Fair Value	$ 41,453,000		$ 47,552,000

Loans Payable - Narrative (Deta

Loans Payable - Narrative (Details) $ / shares in Units, $ in Thousands	1 Months Ended	3 Months Ended
	Sep. 30, 2014USD ($)tranche$ / sharesshares	Mar. 31, 2018USD ($)$ / sharesshares	Mar. 31, 2017USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)$ / sharesshares
Warrants
Interest expense		$ 678	$ 576
Loan and security agreement
Loans Payable
Face amount	$ 35,000
Debt number of tranches | tranche	3
Term Loans A, B and C
Fees
Final payment fee due upon that last payment date of the amounts borrowed under the agreement subject to adjustment (as a percent)		6.60%
Warrants
Gross proceeds		$ 25,333		$ 28,500
Interest expense		$ 400	300
Term Loans A and B
Loans Payable
Interest rate (as a percent)		6.50%
Fees
Prepayment fee percent		1.00%
Term Loan A
Loans Payable
Face amount	$ 2,000
Warrants
Debt discount	$ 1,000
Term Loan A | Warrants | Common Stock
Warrants
Number of shares that can be purchased upon exercise of warrants (in shares) | shares	7,678	5,728
Exercise price (in dollars per share) | $ / shares	$ 5.861
Term Loan B
Loans Payable
Face amount						$ 16,500
Term Loan B | Warrants | Common Stock
Warrants
Number of shares that can be purchased upon exercise of warrants (in shares) | shares						34,961
Exercise price (in dollars per share) | $ / shares						$ 10.6190
Term Loan C
Loans Payable
Face amount			$ 10,000		$ 10,000
Debt borrowing capacity						$ 16,500
Interest rate (as a percent)		6.98%
Term Loan C | Prepayment Date 1
Fees
Prepayment fee percent		2.00%
Term Loan C | Prepayment Date 2
Fees
Prepayment fee percent		1.00%
Term Loan C | Warrants | Common Stock
Warrants
Number of shares that can be purchased upon exercise of warrants (in shares) | shares		62,241
Exercise price (in dollars per share) | $ / shares		$ 3.6150

Loans Payable - Schedule of Deb

Loans Payable - Schedule of Debt (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Loans Payable
Current portion of loans payable, net	$ 12,460	$ 12,425
Loans payable, net	12,595	15,725
Term Loans A, B and C
Loans Payable
Gross proceeds	25,333	28,500
Debt discount and debt issuance costs	(278)	(350)
Carrying value	25,055	28,150
Current portion of loans payable, net	12,460	12,425
Loans payable, net	$ 12,595	$ 15,725

Stockholders' Equity - Equity O

Stockholders' Equity - Equity Offerings (Details) - USD ($) $ / shares in Units, $ in Thousands	Dec. 14, 2015	Mar. 31, 2018	Dec. 31, 2016	Dec. 31, 2017
Equity Offerings
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001		$ 0.001
Issuance of common stock, net of issuance costs		$ 9,154
At Market Sales Facility
Equity Offerings
Issuance of common stock, net of issuance costs (in shares)			5,204,893
Issuance of common stock, net of issuance costs			$ 9,200
Remaining amount available		$ 11,200
At Market Sales Facility | Maximum
Equity Offerings
Offering price	$ 75,000
Commission (as percent)	3.00%
At Market Sales Facility | Weighted-average
Equity Offerings
Offering price (in dollars per share)			$ 1.810

Stockholders' Equity - Equity I

Stockholders' Equity - Equity Incentive Plans (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Stockholders’ Equity
Stock-based compensation	$ 1,498	$ 1,795
Intrinsic value of options exercisable	$ 300
Weighted average exercise price (in dollars per share)	$ 5.49
Employee Stock Option
Stockholders’ Equity
Fair value of underlying instrument (in dollars per share)	$ 1.64
Unrecognized compensation expense	$ 13,700
Weighted average remaining period for recognition of unrecognized compensation expense (in years)	2 years 4 months 17 days
Per-share weighted-average grant date fair value of options granted (in dollars per share)	$ 1.19	$ 3.35
Research and Development Expense [Member]
Stockholders’ Equity
Stock-based compensation	$ 358	$ 707
General and Administrative Expense [Member]
Stockholders’ Equity
Stock-based compensation	$ 1,140	$ 1,088
Inducement Plan
Stockholders’ Equity
Shares available for future grant (in shares)	250,500		293,000
Maximum
Stockholders’ Equity
Term of award (in years)	10 years
Vesting period (in years)	4 years

Stockholders' Equity - Options

Stockholders' Equity - Options Outstanding (Details) - $ / shares	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Number of Shares
Balance at the beginning of the period (in shares)	8,624,223
Granted (in shares)	2,600,625
Exercised (in shares)	(88,048)
Forfeited/Cancelled (in shares)	(739,557)
Balance at the end of the period (in shares)	10,397,243	8,624,223
Vested or expected to vest at the end of the period (in shares)	10,397,243
Exercisable at the end of the period (in shares)	4,186,575
Weighted-Average Exercise Price
Balance at the beginning of the period (in dollars per share)	$ 5.22
Granted (in dollars per share)	1.79
Exercised (in dollars per share)	0.65
Forfeitures/Expirations (in dollars per share)	5.14
Balance at the end of the period (in dollars per share)	4.40	$ 5.22
Vested or expected to vest at the end of the period (in dollars per share)	4.40
Weighted average exercise price (in dollars per share)	$ 5.49
Weighted Average Remaining Contractual Term
Options Outstanding at the end of the period	8 years 4 days	7 years 2 months 12 days
Vested or expected to vest at the end of the period	8 years 4 days
Exercisable at the end of the period	6 years 2 months 23 days

Stockholder's Equity - Shares A

Stockholder's Equity - Shares Available for Future Grant and Issuance (Details) - shares	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018	Dec. 31, 2017
Shares Reserved for Future Issuance
Stock options outstanding (in shares)			10,397,243	8,624,223
Employee stock purchase plan (in shares)			225,806
Warrants outstanding (in shares)			123,091
Total shares of common stock reserved for issuance (in shares)			12,662,116
2013 plan
Shares Available for Future Grant
Balance at the beginning of the period (in shares)	991,613
Authorized (in shares)	2,492,431
Granted (in shares)	(2,505,625)
Forfeitures/Cancelled (in shares)	687,057
Balance at the end of the period (in shares)	1,665,476
Shares Reserved for Future Issuance
Stock options outstanding (in shares)			10,147,743
Shares available for future grant (in shares)	991,613		1,665,476	991,613
Inducement Plan
Shares Available for Future Grant
Balance at the beginning of the period (in shares)	293,000
Granted (in shares)	(95,000)
Forfeitures/Cancelled (in shares)	52,500
Balance at the end of the period (in shares)	250,500
Shares Reserved for Future Issuance
Stock options outstanding (in shares)			249,500
Shares available for future grant (in shares)	293,000		250,500	293,000
Employee Stock Option | Weighted-average
Weighted-average assumptions:
Expected term of options (in years)	5 years 9 months 18 days	6 years 3 months 18 days
Risk-free interest rate (as a percent)	2.70%	2.10%
Expected volatility (as a percent)	76.00%	75.70%
Dividend yield (as a percent)	0.00%	0.00%

Net Loss Per Common Share (Deta

Net Loss Per Common Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Basic and diluted net loss per common share calculation:
Net loss	$ (9,021)	$ (20,714)
Net loss attributable to common stockholders	$ (9,021)	$ (20,714)
Weighted average common shares outstanding (in shares)	64,562,236	56,894,672
Net loss per share of common stock—basic and diluted (in dollars per share)	$ (0.14)	$ (0.36)
Outstanding securities excluded from computation of diluted weighted shares outstanding as they would have been anti dilutive:
Outstanding securities excluded from computation of diluted weighted shares outstanding (in shares)	10,520,334	8,584,526
Employee Stock Option
Outstanding securities excluded from computation of diluted weighted shares outstanding as they would have been anti dilutive:
Outstanding securities excluded from computation of diluted weighted shares outstanding (in shares)	10,397,243	8,461,435
Warrants
Outstanding securities excluded from computation of diluted weighted shares outstanding as they would have been anti dilutive:
Outstanding securities excluded from computation of diluted weighted shares outstanding (in shares)	123,091	123,091

Other Comprehensive Loss (Detai

Other Comprehensive Loss (Details) - USD ($)	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Changes in components of accumulated other comprehensive loss
Balance	$ 34,633,000
Balance	36,317,000
Reclassifications out of accumulated other comprehensive income or loss, net of tax	0	$ 0
Tax effect	0	$ 0
Accumulated Other Comprehensive Income (Loss)
Changes in components of accumulated other comprehensive loss
Balance	(42,000)
Net unrealized loss on marketable securities	(4,000)
Balance	$ (46,000)

Restructuring Charges (Details)

Restructuring Charges (Details) $ in Thousands	Oct. 11, 2017employee	Mar. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Restructuring Charges
Number of positions eliminated, percent of workforce	30.00%
Number of positions eliminated | employee	21
Restructuring charges		$ 23	$ 1,800
Restructuring liability		400	$ 1,100
Employee Severance
Restructuring Charges
Restructuring charges		$ 700

Subsequent Events (Details)

Subsequent Events (Details) - Subsequent Event - Licensing agreements for development and commercialization $ in Millions	1 Months Ended
	May 03, 2018USD ($)
Pharmbio Korea Inc
Subsequent Events
Upfront payment	$ 3
Pharmbio Korea Inc | Maximum
Subsequent Events
Royalties on product sales, percentage	20.00%
Jiangsu Nhwa Pharmaceutical Co Ltd | United States And China
Subsequent Events
Upfront payment	$ 2.5
Milestone payment	$ 3
Jiangsu Nhwa Pharmaceutical Co Ltd | China
Subsequent Events
Royalties on product sales, percentage	10.00%
Jiangsu Nhwa Pharmaceutical Co Ltd | China | Maximum
Subsequent Events
Milestone payment	$ 6