Aclaris Therapeutics (ACRS) 10-Q 11 May 16 2016 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2016	May. 11, 2016
Document and Entity Information
Entity Registrant Name	Aclaris Therapeutics, Inc.
Entity Central Index Key	1,557,746
Document Type	10-Q
Document Period End Date	Mar. 31, 2016
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		20,316,923
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	Q1

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 13,131	$ 9,851
Marketable securities	72,115	75,017
Prepaid expenses and other current assets	1,587	1,656
Total current assets	86,833	86,524
Marketable securities		7,170
Property and equipment, net	417	360
Other assets	20	22
Total assets	87,270	94,076
Current liabilities:
Accounts payable	2,808	810
Accrued expenses	921	745
Total current liabilities	3,729	1,555
Other liabilities	330
Total liabilities	$ 4,059	$ 1,555
Stockholders' Equity:
Common stock, $0.00001 par value; 100,000,000 shares authorized at March 31, 2016 and December 31, 2015; 20,316,923 and 20,157,503 shares issued and outstanding at March 31, 2016 and December 31, 2015, respectively
Additional paid-in capital	$ 139,080	$ 135,503
Accumulated other comprehensive income (loss)	3	(149)
Accumulated deficit	(55,872)	(42,833)
Total stockholders’ equity	83,211	92,521
Total liabilities and stockholders’ equity	$ 87,270	$ 94,076

CONDENSED CONSOLIDATED BALANCE3

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Mar. 31, 2016	Dec. 31, 2015
Condensed Consolidated Balance Sheets
Preferred stock, par value (in dollars per share)	$ 0.00001	$ 0.00001
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value (in dollars per share)	$ 0.00001	$ 0.00001
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	20,316,923	20,157,503
Common stock, shares outstanding	20,316,923	20,157,503

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Operating expenses:
Research and development	$ 9,535	$ 1,737
General and administrative	3,604	892
Total operating expenses	13,139	2,629
Loss from operations	(13,139)	(2,629)
Other income, net	100	6
Net loss	(13,039)	(2,623)
Accretion of convertible preferred stock		(657)
Net loss attributable to common stockholders	$ (13,039)	$ (3,280)
Net loss per share attributable to common stockholders, basic and diluted (in dollars per share)	$ (0.65)	$ (1.61)
Weighted average common shares outstanding, basic and diluted (in shares)	20,171,518	2,034,850
Other comprehensive income (loss):
Unrealized gain on marketable securities, net of tax of $0	$ 142	$ 3
Foreign currency translation adjustments	10
Total other comprehensive income	152	3
Comprehensive loss	$ (12,887)	$ (2,620)

CONDENSED CONSOLIDATED STATEME5

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Condensed Consolidated Statements Of Operations And Comprehensive Loss
Unrealized gain on marketable securities, tax	$ 0	$ 0

CONDENSED CONSOLIDATED STATEME6

CONDENSED CONSOLIDATED STATEMENT OF STOCKHOLDERS' EQUITY - 3 months ended Mar. 31, 2016 - USD ($) $ in Thousands	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit	Total
Balance at Dec. 31, 2015		$ 135,503	$ (149)	$ (42,833)	$ 92,521
Balance (in shares) at Dec. 31, 2015	20,157,503				20,157,503
Increase (Decrease) in Stockholders' Equity
Issuance of common stock in connection with Vixen acquisition		2,355			$ 2,355
Issuance of common stock in connection with Vixen acquisition, shares	159,420
Unrealized gain on marketable securities			142		142
Foreign currency translation adjustment			10		10
Stock-based compensation expense		1,222			1,222
Net loss				(13,039)	(13,039)
Balance at Mar. 31, 2016		$ 139,080	$ 3	$ (55,872)	$ 83,211
Balance (in shares) at Mar. 31, 2016	20,316,923				20,316,923

CONDENSED CONSOLIDATED STATEME7

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Cash flows from operating activities:
Net loss	$ (13,039)	$ (2,623)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation expense	21	3
Stock-based compensation expense	1,222	43
Non-cash charges related to Vixen acquisition	2,784
Changes in operating assets and liabilities:
Prepaid expenses and other assets	71	(626)
Accounts payable	2,008	385
Accrued expenses	39	16
Net cash used in operating activities	(6,894)	(2,802)
Cash flows from investing activities:
Purchases of property and equipment	(40)	(77)
Proceeds from sales and maturities of marketable securities	10,214	822
Net cash provided by investing activities	10,174	745
Cash flows from financing activities:
Payment of deferred offering costs		(231)
Net cash used in financing activities		(231)
Net increase (decrease) in cash and cash equivalents	3,280	(2,288)
Cash and cash equivalents at beginning of period	9,851	10,757
Cash and cash equivalents at end of period	13,131	8,469
Supplemental disclosures of non-cash investing and financing activities:
Additions to property and equipment included in accounts payable	40
Accretion of convertible preferred stock to redemption value		$ 657
Fair value of stock issued in connection with Vixen acquisition on date of issuance	$ 2,355

Organization and Nature of Busi

Organization and Nature of Business	3 Months Ended
	Mar. 31, 2016
Organization and Nature of Business
Organization and Nature of Business	1. Organization and Nature of Business Aclaris Therapeutics, Inc. was incorporated under the laws of the State of Delaware in 2012. On July 17, 2015, Aclaris Therapeutics International Limited (“ATIL”) was established under the laws of the United Kingdom as a wholly-owned subsidiary of Aclaris Therapeutics, Inc. On March 24, 2016, Vixen Pharmaceuticals, Inc. (“Vixen”) became a wholly-owned subsidiary of Aclaris Therapeutics, Inc. (see Note 11). Aclaris Therapeutics, Inc. together with ATIL and Vixen, are referred to collectively as the “Company”. The Company is a clinical ‑stage specialty pharmaceutical company focused on identifying, developing and commercializing innovative and differentiated drugs to address significant unmet needs in dermatology. The Company’s lead drug candidate, A ‑101, is a proprietary high ‑concentration hydrogen peroxide topical solution that is being developed as a prescription treatment for seborrheic keratosis (“SK”), a common non ‑malignant skin tumor. The Company has completed three Phase 2 clinical trials, and is currently conducting three Phase 3 clinical trials, of A-101 in patients with SK. Initial Public Offering On October 6, 2015, the Company’s registration statement on Form S-1 relating to its initial public offering of its common stock (the “IPO”) was declared effective by the Securities and Exchange Commission (“SEC”). The Company’s common stock began trading on The NASDAQ Global Select Market on October 7, 2015. The IPO closed on October 13, 2015, and 5,000,000 shares of common stock were sold at a price to the public of $11.00 per share, for aggregate gross proceeds of $55,000 . In addition, upon the closing of the IPO, all of the Company’s outstanding convertible preferred stock was converted into an aggregate total of 11,677,076 shares of common stock. On October 12, 2015, the underwriters of the IPO exercised in full their option to purchase additional shares, and on October 13, 2015, the Company sold 750,000 additional shares of common stock at a price to the public of $11.00 per share, for aggregate gross proceeds of $8,250 . The Company paid underwriting discounts and commissions of $4,428 to the underwriters in connection with the IPO, including the underwriters’ exercise of their option to purchase additional shares. In addition, the Company incurred expenses of $2,272 in connection with the IPO. The net offering proceeds received by the Company, after deducting underwriting discounts, commissions and offering expenses, were $56,550 . Reverse Stock Split On September 24, 2015, the Company effected a 1 ‑for ‑3.45 reverse stock split of its issued and outstanding shares of common stock and a proportional adjustment to the existing conversion ratios for each series of the Company’s then-outstanding convertible preferred stock. Accordingly, all share and per share amounts for all periods presented in these condensed consolidated financial statements and notes thereto have been adjusted retroactively, where applicable, to reflect this reverse stock split and adjustment of the preferred stock conversion ratios. Liquidity The Company’s condensed consolidated financial statements have been prepared on the basis of continuity of operations, realization of assets and the satisfaction of liabilities in the ordinary course of business. At March 31, 2016, the Company had cash, cash equivalents and marketable securities of $85,246 and an accumulated deficit of $55,872 . The Company has not generated any product revenues and has not achieved profitable operations. There is no assurance that profitable operations will ever be achieved, and, if achieved, will be sustained on a continuing basis. In addition, development activities, clinical and pre-clinical testing, and commercialization of the Company’s products will require significant additional financing. The future viability of the Company is dependent on its ability to generate cash from operating activities or to raise additional capital to finance its operations. The Company’s failure to raise capital as and when needed could have a negative impact on its financial condition and ability to pursue its business strategies.

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2016
Summary of Significant Accounting Policies
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Basis of Presentation The accompanying condensed consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”). The financial statements include the consolidated accounts of the Company and its wholly-owned subsidiaries. All intercompany transactions have been eliminated. Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of expenses during the reporting periods. Significant estimates and assumptions reflected in these financial statements include, but are not limited to, research and development expenses and the valuation of stock-based awards. Estimates are periodically reviewed in light of changes in circumstances, facts and experience. Actual results could differ from the Company’s estimates. Unaudited Interim Financial Information The accompanying condensed consolidated balance sheet as of March 31, 2016, the condensed consolidated statements of operations and comprehensive loss for the three months ended March 31, 2016 and 2015, the condensed consolidated statement of stockholders’ equity for the three months ended March 31, 2016, and the condensed consolidated statements of cash flows for the three months ended March 31, 2016 and 2015 are unaudited. The unaudited interim condensed consolidated financial statements have been prepared on the same basis as the audited annual financial statements contained in the Company’s annual report on Form 10-K filed with the SEC on March 23, 2016 and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary for the fair statement of the Company’s financial position as of March 31, 2016, the results of its operations and comprehensive loss for the three months ended March 31, 2016 and 2015 and its cash flows for the three months ended March 31, 2016 and 2015. The condensed consolidated balance sheet data as of December 31, 2015 was derived from audited financial statements but does not include all disclosures required by accounting principles generally accepted in the United States. The financial data and other information disclosed in these notes related to the three months ended March 31, 2016 and 2015 are unaudited. The results for the three months ended March 31, 2016 are not necessarily indicative of results to be expected for the year ending December 31, 2016, any other interim periods, or any future year or period. The unaudited interim financial statements of the Company included herein have been prepared, pursuant to the rules and regulations of the SEC. Certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted from this report, as is permitted by such rules and regulations. These unaudited condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and the notes thereto for the year ended December 31, 2015 included in the Company’s annual report on Form 10-K filed with the SEC on March 23, 2016. Significant Accounting Policies The Company’s significant accounting policies are disclosed in the audited consolidated financial statements for the year ended December 31, 2015 included in the Company’s annual report on Form 10-K filed with the SEC on March 23, 2016. Since the date of such financial statements, there have been no changes to the Company’s significant accounting policies. Assets Held for Sale In order for an asset to be classified as held for sale there must be an active program to market the asset, and it must be probable the asset will be disposed of within one year. The carrying value of an asset held for sale is reported at the lower of its carrying value or its fair value less costs to sell. No additional depreciation expense is recognized once an asset is classified as held for sale. All current and historical balance sheet information for the Company’s assets held for sale is included in prepaid expenses and other current assets in the accompanying condensed consolidated balance sheets. As of March 31, 2016 and December 31, 2015, $216 in assets were classified as held for sale. Recently Issued Accounting Pronouncements In March 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2016-09, Improvements to Employee Share-Based Payment Accounting . This ASU requires all tax effects of share-based payment settlements to be recorded through the income statement. Currently, tax benefits in excess of compensation cost, or “windfalls”, are recorded in equity, and tax deficiencies, or “shortfalls”, are recorded to equity to the extent of previous windfalls, and then to the income statement. In addition, under the new guidance, companies will be permitted to make a policy election to recognize the impact of forfeitures either when they occur, or on an estimated basis. Finally, this update simplifies withholding requirements to allow companies to withhold up to an employee’s maximum tax rate without resulting in liability classification for the award. ASU 2016-09 is effective for annual reporting periods beginning after December 15, 20 1 6, and early adoption is permitted. The Company has adopted the provisions of this standard early, the impact of which on its consolidated financial statements was not significant .

Fair Value of Financial Assets

Fair Value of Financial Assets and Liabilities	3 Months Ended
	Mar. 31, 2016
Fair Value of Financial Assets and Liabilities
Fair Value of Financial Assets and Liabilities	3. Fair Value of Financial Assets and Liabilities The following tables present information about the Company’s assets and liabilities measured at fair value on a recurring basis and indicate the level of the fair value hierarchy utilized to determine such fair values: Fair Value Measurements as of March 31, 2016 Using: Level 1 Level 2 Level 3 Total Assets: Cash equivalents $ $ — $ — $ Marketable securities — — Total $ $ $ — $ Fair Value Measurements as of December 31, 2015 Using: Level 1 Level 2 Level 3 Total Assets: Cash equivalents $ $ $ — $ Marketable securities — — Total $ $ $ — $ As of March 31, 2016 and December 31, 2015, the Company’s cash equivalents consisted of money market funds with original maturities of less than three months. The Company valued its money market funds based on Level 1 inputs. In determining the fair value of its marketable securities as of March 31, 2016 and December 31, 2015, the Company relied on quoted prices for identical securities in markets that are not active, a Level 2 input. These quoted prices were obtained by the Company with the assistance of a third-party pricing service based on available trade, bid and other observable market data for identical securities. Quarterly, the Company compares the quoted prices obtained from the third-party pricing service to other available independent pricing information to validate the reasonableness of the quoted prices provided. The Company evaluates whether adjustments to third-party pricing is necessary and, historically, the Company has not made adjustments to quoted prices obtained from the third-party pricing service. During the three months ended March 31, 2016 and the year ended December 31, 2015, there were no transfers between Level 1 , Level 2 and Level 3 . As of March 31, 2016 and December 31, 2015, the fair value of the Company’s available for sale marketable securities by type of security was as follows: March 31, 2016 Gross Gross Amortized Unrealized Unrealized Fair Cost Gain Loss Value Marketable securities: Corporate debt securities $ $ $ $ Commercial paper — — Asset-backed securities — U.S. government agency debt securities — Total marketable securities $ $ $ $ December 31, 2015 Gross Gross Amortized Unrealized Unrealized Fair Cost Gain Loss Value Marketable securities: Corporate debt securities $ $ — $ $ Commercial paper — — Asset-backed securities — U.S. government agency debt securities — Total marketable securities $ $ — $ $ As of March 31, 2016 and December 31, 2015, the Company’s investments in corporate debt securities had credit ratings of A and above and remaining maturities of less than 12 months and less than 15 months, respectively.

Property and Equipment, Net

Property and Equipment, Net	3 Months Ended
	Mar. 31, 2016
Property and Equipment, Net
Property and Equipment, Net	4. Property and Equipment, Net Property and equipment, net consisted of the following: March 31, December 31, 2016 2015 Computer equipment $ $ Manufacturing equipment Furniture and fixtures Property and equipment, gross Less: Accumulated depreciation Total property and equipment, net $ $ Depreciation expense was $21 and $3 for the three months ended March 31, 2016 and 2015, respectively.

Accrued Expenses

Accrued Expenses	3 Months Ended
	Mar. 31, 2016
Accrued Expenses
Accrued Expenses	5. Accrued Expenses Accrued expenses consisted of the following: March 31, December 31, 2016 2015 Research and development expenses $ $ Employee-related expenses — Licensing fees — Vixen contract payable — Professional fees Other Total accrued expenses $ $

Stockholders' Equity (Deficit)

Stockholders' Equity (Deficit)	3 Months Ended
	Mar. 31, 2016
Stockholders' Equity (Deficit)
Stockholders' Equity (Deficit)	6. Stockholders’ Equity Preferred Stock As of March 31, 2016 and December 31, 2015, the Company’s certificate of incorporation, as amended and restated, authorized the Company to issue 10,000,000 shares of undesignated preferred stock. No shares of preferred stock were outstanding at March 31, 2016 or December 31, 2015. Common Stock As of March 31, 2016 and December 31, 2015, the Company’s certificate of incorporation, as amended and restated, authorized the Company to issue 100,000,000 shares of $0.00001 par value common stock. Each share of common stock entitles the holder to one vote on all matters submitted to a vote of the Company’s stockholders. Common stockholders are entitled to receive dividends, as may be declared by the board of directors, if any, subject to any preferential dividend rights of any series of preferred stock that may be outstanding. No dividends had been declared through March 31, 2016.

Stock-Based Awards

Stock-Based Awards	3 Months Ended
	Mar. 31, 2016
Stock-Based Awards
Stock-Based Awards	7. Stock ‑Based Awards 2012 Equity Compensation Plan Upon the 2015 Equity Incentive Plan (the “2015 Plan”), described below, becoming effective, no further grants may be made under the 2012 Equity Compensation Plan, as amended and restated (the “2012 Plan”). The Company granted a total of 1,140,524 stock options under the 2012 Plan, all of which were outstanding as of both March 31, 2016 and December 31, 2015. Stock options granted under the 2012 Plan vest over four years and expire after ten years. As required, the exercise price for the stock options granted under the 2012 Plan was not less than the fair value of common shares as determined by the Company as of the date of grant. 2015 Equity Incentive Plan On September 15, 2015, the Company’s board of directors adopted and on September 16, 2015, the Company’s stockholders approved the 2015 Plan, which became effective in connection with the IPO in October 2015. The 2015 Plan provides for the grant of incentive stock options, nonstatutory stock options, stock appreciation rights, restricted stock awards, restricted stock unit (“RSU”) awards, performance stock awards, cash-based awards and other stock-based awards. The number of shares initially reserved for issuance under the 2015 Plan was 2,784,395 shares of common stock. The number of shares of common stock that may be issued under the 2015 Plan will automatically increase on January 1 of each year, beginning on January 1, 2016 and ending on January 1, 2025, in an amount equal to the lesser of (i) 4.0% of the shares of the Company’s common stock outstanding on December 31 of the preceding calendar year or (ii) an amount determined by the Company’s board of directors. The shares of common stock underlying any awards that expire, are otherwise terminated, settled in cash or repurchased by the Company under the 2015 Plan and the 2012 Plan will be added back to the shares of common stock available for issuance under the 2015 Plan. As of January 1, 2016, the number of shares of common stock that may be issued under the 2015 Plan was automatically increased by 806,300 shares. As of March 31, 2016, 2,856,695 shares remained available for grant under the 2015 Plan. Stock Option Valuation The weighted average assumptions the Company used to determine the fair value of stock options granted during the three months ended March 31, 2016 were as follows,: Three Months Ended March 31, 2016 Risk-free interest rate % Expected term (in years) Expected volatility % Expected dividend yield % No stock options were granted during the three months ended March 31, 2015. The Company recognizes compensation expense for only the portion of awards that are expected to vest. For the three months ended March 31, 2016, the Company applied an expected forfeiture rate of 0% . Stock Options The following table summarizes stock option activity under the 2012 Plan and 2015 Plan from January 1, 2016 through March 31, 2016: Weighted Weighted Average Average Remaining Aggregate Number Exercise Contractual Intrinsic of Shares Price Term Value (in years) Outstanding as of December 31, 2015 $ Granted Exercised — — Forfeited and canceled — — Outstanding as of March 31, 2016 $ $ Options vested and expected to vest as of March 31, 2016 $ $ Options exercisable as of March 31, 2016 (1) $ $ (1) All options granted under the 2012 Plan are exercisable immediately, subject to a repurchase right in the Company’s favor that lapses as the option vests. This amount reflects the number of shares under options that were vested, as opposed to exercisable, as of March 31, 2016. The weighted average grant ‑date fair value of stock options granted during the three months ended March 31, 2016 was $16.75 per share. The aggregate intrinsic value of stock options is calculated as the difference between the exercise price of the stock options and the fair value of the Company’s common stock for those stock options that had exercise prices lower than the fair value of the Company’s common stock. Restricted Stock Units A summary of the status of the Company’s RSUs at March 31, 2016 and of changes in RSUs outstanding under the 2015 Plan for the three months ended March 31, 2016 is as follows: Weighted Average Grant Date Number Fair Value of Shares Per Share Outstanding at December 31, 2015 $ Granted Vested — — Forfeited and cancelled — — Outstanding at March 31, 2016 $ The Company did not grant RSUs during the three months ended March 31, 2015 . Stock ‑Based Compensation For the three months ended March 31, 2016 and 2015, the Company recorded stock ‑based compensation in the following expense categories of its statements of operations and comprehensive loss: Three Months Ended March 31, 2016 2015 Research and development $ $ General and administrative $ $ As of March 31, 2016, the Company had an aggregate of $18,807 of unrecognized stock ‑based compensation cost, which is expected to be recognized over a weighted average period of 3.29 years.

Net Loss per Share

Net Loss per Share	3 Months Ended
	Mar. 31, 2016
Net Loss per Share
Net Loss per Share	8. Net Loss per Share Basic and diluted net loss per share attributable to common stockholders was calculated as follows: Three Months Ended March 31, 2016 2015 Numerator: Net loss $ $ Accretion of redeemable convertible preferred stock to redemption value — Net loss attributable to common stockholders $ $ Denominator: Weighted average shares of common stock outstanding Less: Weighted average shares of unvested restricted common stock outstanding — Weighted average common shares outstanding used in calculating net loss per share attributable to common stockholders, basic and diluted Net loss per share attributable to common stockholders, basic and diluted $ $ The Company’s potentially dilutive securities, which include stock options, RSUs, preferred stock and shares of restricted common stock that were issued but have not yet vested, have been excluded from the computation of diluted net loss per share as the effect would be to reduce the net loss per share. Therefore, the weighted average number of common shares outstanding used to calculate both basic and diluted net loss per share attributable to common stockholders is the same. The following potential common shares, presented based on amounts outstanding at each period end, were excluded from the calculation of diluted net loss per share attributable to common stockholders for the three months ended March 31, 2016 and 2015 because including them would have had an anti-dilutive effect: Three Months Ended March 31, 2016 2015 Stock options to purchase common stock Restricted stock unit awards — Unvested restricted common stock — Convertible preferred stock (as converted to common stock) —

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2016
Commitments and Contingencies
Commitments and Contingencies	9. Commitments and Contingencies Sublease In August 2013, the Company entered into a sublease agreement with a related party (see Note 10) for its office space with a term ending on November 30, 2016. As part of an amendment to the sublease agreement entered into in December 2014, the Company increased the amount of office space to be subleased and agreed to new monthly terms commencing in January 2015. On August 14, 2015, the Company further amended its sublease agreement to increase the square footage of the space and to extend the term of the lease to November 2019. Effective December 1, 2015, the Company further amended its sublease agreement to increase the square footage and agreed to new monthly sublease terms. Rent expense under operating leases was $52 and $26 for the three months ended March 31, 2016 and 2015, respectively. The Company recognizes rent expense on a straight-line basis over the lease period and has accrued for rent expense incurred but not yet paid. As of March 31, 2016, future minimum lease payments under the sublease were as follows: Years Ending December 31, 2016 $ 2017 2018 2019 2020 — Total $

Related Party Transactions

Related Party Transactions	3 Months Ended
	Mar. 31, 2016
Related Party Transactions
Related Party Transactions	10. Related Party Transactions In August 2013, the Company entered into a sublease agreement with NeXeption, Inc. ("NeXeption"), which was subsequently amended in December 2014 and August 2015. In August 2015, pursuant to an Assignment and Assumption Agreement, NeXeption, Inc. assigned all interests, rights, duties and obligations under the Amended and Restated Sublease to NST Consulting, LLC, a wholly owned subsidiary of NST, LLC. Mr. Stephen Tullman, the chairman of the Company’s board of directors, was an executive officer of NeXeption and is also the manager of NST Consulting, LLC and NST, LLC. Total payments made during the three months ended March 31, 2016 and 2015 under these sublease agreements were $52 and $26 , respectively. In February 2014, the Company entered into a services agreement with NST, LLC (the “NST services agreement”), pursuant to which NST, LLC provided certain pharmaceutical development, management and other administrative services to the Company. Under the same agreement, the Company also provided services to another company under common control with the Company and NST LLC and was reimbursed by NST LLC for those services. In addition to Mr. Tullman’s role as manager of NST, LLC, several of the Company’s executive officers are members of NST, LLC. The NST services agreement was amended in January 2015 pursuant to which NST, LLC assigned all interests, rights, duties and obligations under the NST services agreement to NST Consulting, LLC. Under the agreement, as amended, NST Consulting, LLC provides services to the Company and the Company provides services t o another company under common control with the Company and NST Consulting, LLC. The NST services agreement was further amended in August 2015, and November 2015 to adjust the amount of services the Company is obligated to provide to NST Consulting, LLC and the amount of services NST Consulting, LLC is obligated to provide to the Company. The Company may offset any payments owed by the Company to NST Consulting, LLC against payments that are owed by NST Consulting, LLC to the Company for the provision of personnel, including consultants, to the Company. During the three months ended March 31, 2016 and 2015 gross expenses incurred by the Company under the services agreement totaled $140 and $123 , respectively, and gross expenses charged by the Company totaled $36 and $112 , respectively. For the three months ended March 31, 2016 and 2015 the Company recorded $64 and $75 , respectively, of general and administrative expenses related to these transactions. For the three months ended March 31, 2016 the Company recorded $40 of research and development expenses related to these transactions. For the three months ended March 31, 2015, the Company recorded $64 as a reduction of research and development expenses related to these transactions. During the three months ended March 31, 2016 and 2015 payments made by the Company pursuant to the NST services agreement totaled $58 , and $15 , respectively. Related to this agreement, $29 was due to NST Consulting, LLC at March 31, 2016.

Agreements Related to Intellect

Agreements Related to Intellectual Property	3 Months Ended
	Mar. 31, 2016
Agreements Related to Intellectual Property
Agreements Related to Intellectual Property	11. Agreements Related to Intellectual Property Assignment Agreement and Finder’s Services Agreement In August 2012, the Company entered into an assignment agreement with the Estate of Mickey Miller, or the Miller Estate, under which the Company acquired some of the intellectual property rights covering A-101. In connection with obtaining the assignment of the intellectual property from the Miller Estate, the Company also entered into a separate finder’s services agreement with KPT Consulting, LLC. In February 2016, u nder the terms of the assignment agreement and the finder’s services agreement, the Company made a one-time milestone payment of $300 upon the dosing of the first human subject with A-101 in the Company’s Phase 3 clinical trial. The payment was recorded as general and administrative expense during the three months ended March 31, 2016. Under the finder’s services agreement, the Company is obligated to make additional milestone payments of up to $1,000 in the aggregate upon the achievement of specified development and regulatory milestones and up to $4,500 upon the achievement of specified commercial milestones. Under each of the assignment agreement and the finder’s services agreement, the Company is also obligated to pay royalties on sales of A-101 or related products, at low single-digit percentages of net sales, subject to reduction in specified circumstances. The Company has not made any royalty payments to date under either agreement. Both agreements will terminate upon the expiration of the last pending, viable patent claim of the patents acquired under the assignment agreement, but no sooner than 15 years from the effective date of the agreements. Stock Purchase Agreement with Vixen Pharmaceuticals, Inc. and License Agreement with Columbia University On March 24, 2016, the Company entered into a stock purchase agreement (the “Vixen Agreement”) with Vixen, JAK1, LLC, JAK2, LLC and JAK3, LLC (together with JAK1, LLC and JAK2, LLC, the “Selling Stockholders”) and Shareholder Representative Services LLC, a Colorado limited liability company, solely in its capacity as the representative of the Selling Stockholders. Pursuant to the Vixen Agreement, the Company acquired all shares of Vixen’s capital stock from the Selling Stockholders (the “Vixen Acquisition”). Following the Vixen Acquisition, Vixen will continue as a wholly owned subsidiary of the Company. Pursuant to the Vixen Agreement, the Company paid $600 upfront and issued an aggregate of 159,420 shares of the Company’s common stock to the Selling Stockholders. The Company is obligated to make annual payments of $100 on March 24 th of each year, through March 24, 2022, with such amounts being creditable against specified future payments that may be paid under the Vixen Agreement. The Company is obligated to make aggregate payments of up to $18,000 to the Selling Stockholders upon the achievement of specified pre-commercialization milestones for three products in the United States, the European Union and Japan, and aggregate payments of up to $22,500 upon the achievement of specified commercial milestones. With respect to any commercialized products covered by the Vixen Agreement, the Company is obligated to pay low single-digit royalties on net sales, subject to specified reductions, limitations and other adjustments, until the date that all of the patent rights for that product have expired, as determined on a country-by-country and product-by-product basis or, in specified circumstances, ten years from the first commercial sale of such product. If the Company sublicenses any of Vixen’s patent rights and know-how acquired pursuant to the Vixen Agreement, the Company will be obligated to pay a portion of any consideration the Company receives from such sublicenses in specified circumstances. As a result of the transaction with Vixen, the Company became party to the Exclusive License Agreement, by and between Vixen and the Trustees of Columbia University in the City of New York (“ Columbia ”), dated as of December 31, 2015 (the “ License Agreement ”). Under the License Agreement, the Company is obligated to pay Columbia an annual license fee of $10 , subject to specified adjustments for patent expenses incurred by Columbia and creditable against any royalties that may be paid under the License Agreement. The Company is also obligated to pay up to an aggregate of $11,600 upon the achievement of specified commercial milestones, including specified levels of net sales of products covered by Columbia patent rights and/or know-how, and royalties at a sub-single-digit percentage of annual net sales of products covered by Columbia patent rights and/or know-how, subject to specified adjustments. If the Company sublicenses any of Columbia’s patent rights and know-how acquired pursuant to the License Agreement, it will be obligated to pay Columbia a portion of any consideration received from such sublicenses in specified circumstances. The royalties, as determined on a country-by-country and product-by-product basis, are payable until the date that all of the patent rights for that product have expired, the expiration of any market exclusivity period granted by a regulatory body or, in specified circumstances, ten years from the first commercial sale of such product. The License Agreement terminates on the date of expiration of all royalty obligations thereunder unless earlier terminated by either party for a material breach, subject to a specified cure period. The Company may also terminate the License Agreement without cause at any time upon advance written notice to Columbia. The Company accounted for the transaction with Vixen as an asset acquisition as the arrangement did not meet the definition of a business pursuant to the guidance prescribed in Accounting Standards Codification Topic 805, Business Combinations . The Company concluded the transaction with Vixen did not meet the definition of a business because the transaction principally resulted in the acquisition of the License Agreement. The Company did not acquire tangible assets, processes, protocols or operating systems. In addition, at the time of the transaction, there were no activities being conducted related to the licensed patents. The Company will expense the acquired intellectual property asset as of the acquisition date on the basis that the cost of intangible assets purchased from others for use in research and development activities, and that have no alternative future uses, are expensed at the time the costs are incurred. Accordingly, the Company recorded the $600 upfront payment, the fair value of the shares of common stock issued of $2,355 , and the present value of the six non-contingent annual payments as research and development expense in the three months ended March 31, 2016. Additionally, the Company will record as expense any contingent milestone payments or royalties in the period in which such liabilities are incurred.

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2016
Income Taxes
Income Taxes	12. Income Taxes The Company did not record a federal or state income tax benefit for the Company’s losses for the three months ended March 31, 2016 and 2015 due to the Company’s conclusion that a valuation allowance is required.

Summary of Significant Accoun20

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2016
Summary of Significant Accounting Policies
Basis of Presentation	Basis of Presentation The accompanying condensed consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”). The financial statements include the consolidated accounts of the Company and its wholly-owned subsidiaries. All intercompany transactions have been eliminated.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of expenses during the reporting periods. Significant estimates and assumptions reflected in these financial statements include, but are not limited to, research and development expenses and the valuation of stock-based awards. Estimates are periodically reviewed in light of changes in circumstances, facts and experience. Actual results could differ from the Company’s estimates.
Unaudited Interim Financial Information Policy [Policy TextBlock]	Unaudited Interim Financial Information The accompanying condensed consolidated balance sheet as of March 31, 2016, the condensed consolidated statements of operations and comprehensive loss for the three months ended March 31, 2016 and 2015, the condensed consolidated statement of stockholders’ equity for the three months ended March 31, 2016, and the condensed consolidated statements of cash flows for the three months ended March 31, 2016 and 2015 are unaudited. The unaudited interim condensed consolidated financial statements have been prepared on the same basis as the audited annual financial statements contained in the Company’s annual report on Form 10-K filed with the SEC on March 23, 2016 and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary for the fair statement of the Company’s financial position as of March 31, 2016, the results of its operations and comprehensive loss for the three months ended March 31, 2016 and 2015 and its cash flows for the three months ended March 31, 2016 and 2015. The condensed consolidated balance sheet data as of December 31, 2015 was derived from audited financial statements but does not include all disclosures required by accounting principles generally accepted in the United States. The financial data and other information disclosed in these notes related to the three months ended March 31, 2016 and 2015 are unaudited. The results for the three months ended March 31, 2016 are not necessarily indicative of results to be expected for the year ending December 31, 2016, any other interim periods, or any future year or period. The unaudited interim financial statements of the Company included herein have been prepared, pursuant to the rules and regulations of the SEC. Certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted from this report, as is permitted by such rules and regulations. These unaudited condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and the notes thereto for the year ended December 31, 2015 included in the Company’s annual report on Form 10-K filed with the SEC on March 23, 2016.
Significant Accounting Policies [Policy TextBlock]	Significant Accounting Policies The Company’s significant accounting policies are disclosed in the audited consolidated financial statements for the year ended December 31, 2015 included in the Company’s annual report on Form 10-K filed with the SEC on March 23, 2016. Since the date of such financial statements, there have been no changes to the Company’s significant accounting policies.
Assets Held For Sale, Policy [Policy Text Block]	Assets Held for Sale In order for an asset to be classified as held for sale there must be an active program to market the asset, and it must be probable the asset will be disposed of within one year. The carrying value of an asset held for sale is reported at the lower of its carrying value or its fair value less costs to sell. No additional depreciation expense is recognized once an asset is classified as held for sale. All current and historical balance sheet information for the Company’s assets held for sale is included in prepaid expenses and other current assets in the accompanying condensed consolidated balance sheets. As of March 31, 2016 and December 31, 2015, $216 in assets were classified as held for sale.
Recently Issued And Adopted Accounting Pronouncements	Recently Issued Accounting Pronouncements In March 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2016-09, Improvements to Employee Share-Based Payment Accounting . This ASU requires all tax effects of share-based payment settlements to be recorded through the income statement. Currently, tax benefits in excess of compensation cost, or “windfalls”, are recorded in equity, and tax deficiencies, or “shortfalls”, are recorded to equity to the extent of previous windfalls, and then to the income statement. In addition, under the new guidance, companies will be permitted to make a policy election to recognize the impact of forfeitures either when they occur, or on an estimated basis. Finally, this update simplifies withholding requirements to allow companies to withhold up to an employee’s maximum tax rate without resulting in liability classification for the award. ASU 2016-09 is effective for annual reporting periods beginning after December 15, 20 1 6, and early adoption is permitted. The Company has adopted the provisions of this standard early, the impact of which on its consolidated financial statements was not significant .

Fair Value of Financial Asset21

Fair Value of Financial Assets and Liabilities (Tables)	3 Months Ended
	Mar. 31, 2016
Fair Value of Financial Assets and Liabilities
Schedule of assets and liabilities measured at fair value on a recurring basis	Fair Value Measurements as of March 31, 2016 Using: Level 1 Level 2 Level 3 Total Assets: Cash equivalents $ $ — $ — $ Marketable securities — — Total $ $ $ — $ Fair Value Measurements as of December 31, 2015 Using: Level 1 Level 2 Level 3 Total Assets: Cash equivalents $ $ $ — $ Marketable securities — — Total $ $ $ — $
Schedule of the fair value of available for sale marketable securities by type of security	March 31, 2016 Gross Gross Amortized Unrealized Unrealized Fair Cost Gain Loss Value Marketable securities: Corporate debt securities $ $ $ $ Commercial paper — — Asset-backed securities — U.S. government agency debt securities — Total marketable securities $ $ $ $ December 31, 2015 Gross Gross Amortized Unrealized Unrealized Fair Cost Gain Loss Value Marketable securities: Corporate debt securities $ $ — $ $ Commercial paper — — Asset-backed securities — U.S. government agency debt securities — Total marketable securities $ $ — $ $

Property and Equipment, Net (Ta

Property and Equipment, Net (Tables)	3 Months Ended
	Mar. 31, 2016
Property and Equipment, Net
Schedule of property and equipment, net	March 31, December 31, 2016 2015 Computer equipment $ $ Manufacturing equipment Furniture and fixtures Property and equipment, gross Less: Accumulated depreciation Total property and equipment, net $ $

Accrued Expenses (Tables)

Accrued Expenses (Tables)	3 Months Ended
	Mar. 31, 2016
Accrued Expenses
Schedule of accrued expenses	March 31, December 31, 2016 2015 Research and development expenses $ $ Employee-related expenses — Licensing fees — Vixen contract payable — Professional fees Other Total accrued expenses $ $

Stock-Based Awards (Tables)

Stock-Based Awards (Tables)	3 Months Ended
	Mar. 31, 2016
Stock-Based Awards
Assumptions used to determine fair value of stock options granted	Three Months Ended March 31, 2016 Risk-free interest rate % Expected term (in years) Expected volatility % Expected dividend yield %
Summary of stock option activity	Weighted Weighted Average Average Remaining Aggregate Number Exercise Contractual Intrinsic of Shares Price Term Value (in years) Outstanding as of December 31, 2015 $ Granted Exercised — — Forfeited and canceled — — Outstanding as of March 31, 2016 $ $ Options vested and expected to vest as of March 31, 2016 $ $ Options exercisable as of March 31, 2016 (1) $ $ (1) All options granted under the 2012 Plan are exercisable immediately, subject to a repurchase right in the Company’s favor that lapses as the option vests. This amount reflects the number of shares under options that were vested, as opposed to exercisable, as of March 31, 2016.
Summary of RSU activity	Weighted Average Grant Date Number Fair Value of Shares Per Share Outstanding at December 31, 2015 $ Granted Vested — — Forfeited and cancelled — — Outstanding at March 31, 2016 $
Stock-based compensation expense	Three Months Ended March 31, 2016 2015 Research and development $ $ General and administrative $ $

Net Loss per Share (Tables)

Net Loss per Share (Tables)	3 Months Ended
	Mar. 31, 2016
Net Loss per Share
Basic and diluted net loss per share attributable to common stockholders	Three Months Ended March 31, 2016 2015 Numerator: Net loss $ $ Accretion of redeemable convertible preferred stock to redemption value — Net loss attributable to common stockholders $ $ Denominator: Weighted average shares of common stock outstanding Less: Weighted average shares of unvested restricted common stock outstanding — Weighted average common shares outstanding used in calculating net loss per share attributable to common stockholders, basic and diluted Net loss per share attributable to common stockholders, basic and diluted $ $
Potential common shares excluded from the calculation of diluted net loss per share attributable to common stockholders	Three Months Ended March 31, 2016 2015 Stock options to purchase common stock Restricted stock unit awards — Unvested restricted common stock — Convertible preferred stock (as converted to common stock) —

Commitments and Contingencies (

Commitments and Contingencies (Tables)	3 Months Ended
	Mar. 31, 2016
Commitments and Contingencies
Schedule of future minimum lease payments under the sublease	Years Ending December 31, 2016 $ 2017 2018 2019 2020 — Total $

Organization and Nature of Bu27

Organization and Nature of Business (Details)	Mar. 31, 2016item
A101
Production information
Number of clinical trials completed	3

Organization and Nature of Bu28

Organization and Nature of Business - IPO, Stock Split, Liquidity (Details) $ / shares in Units, $ in Thousands	Oct. 13, 2015USD ($)$ / sharesshares	Sep. 24, 2015	Mar. 31, 2016USD ($)	Mar. 31, 2015USD ($)	Dec. 31, 2015USD ($)
Initial public offering
Aggregate gross proceeds			$ 2,355
Common stock shares issued upon conversion of convertible preferred stock | shares	11,677,076
Payments of initial public offering costs				$ 231
Reverse stock split		0.2899
Accumulated deficit			55,872		$ 42,833
Cash, cash equivalents and marketable securities			$ 85,246
IPO
Initial public offering
Number of shares issued in offering | shares	5,000,000
Issuance price (in dollars per share) | $ / shares	$ 11
Aggregate gross proceeds	$ 55,000
Payments of initial public offering costs	2,272
Offering proceeds, net of discounts, commissions and expenses	$ 56,550
Exercise of over-allotment option
Initial public offering
Number of shares issued in offering | shares	750,000
Issuance price (in dollars per share) | $ / shares	$ 11
Aggregate gross proceeds	$ 8,250
Payments of initial public offering costs	$ 4,428

Summary of Significant Accoun29

Summary of Significant Accounting Policies (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Dec. 31, 2015
Summary of Significant Accounting Policies
Assets Held For Sale Maximum Holding Period	1 year
Assets held for sale	$ 216	$ 216

Fair Value of Financial Asset30

Fair Value of Financial Assets and Liabilities (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2016	Dec. 31, 2015
Assets:
Marketable securities	$ 72,115	$ 82,187
Transfers from Level 1 to Level 2	0	0
Transfers from Level 2 to Level 1	0	0
Transfers into or out of Level 3	0	0
Recurring
Assets:
Cash equivalents	11,179	9,060
Marketable securities	72,115	82,187
Total assets measured at fair value	83,294	91,247
Recurring | Level 1
Assets:
Cash equivalents	11,179	8,810
Total assets measured at fair value	11,179	8,810
Recurring | Level 2
Assets:
Cash equivalents		250
Marketable securities	72,115	82,187
Total assets measured at fair value	$ 72,115	$ 82,437

Fair Value of Financial Asset31

Fair Value of Financial Assets and Liabilities - by type (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2016	Dec. 31, 2015
Marketable securities:
Amortized Cost	$ 72,127	$ 82,341
Gross Unrealized Gain	15
Gross Unrealized Loss	(27)	(154)
Fair Value	72,115	82,187
Corporate debt securities
Marketable securities:
Amortized Cost	38,889	46,270
Gross Unrealized Gain	4
Gross Unrealized Loss	(27)	(125)
Fair Value	$ 38,866	$ 46,145
Corporate debt securities | Maximum
Marketable securities:
Remaining term of maturities (in months)	12 months	15 months
Commercial paper
Marketable securities:
Amortized Cost	$ 6,999	$ 9,789
Fair Value	6,999	9,789
Asset-backed Securities [Member]
Marketable securities:
Amortized Cost	6,205	6,234
Gross Unrealized Gain	1
Gross Unrealized Loss		(14)
Fair Value	6,206	6,220
U.S. government agency debt securities
Marketable securities:
Amortized Cost	20,034	20,048
Gross Unrealized Gain	10
Gross Unrealized Loss		(15)
Fair Value	$ 20,044	$ 20,033

Property and Equipment, Net (De

Property and Equipment, Net (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Property and Equipment, net
Property and equipment	$ 480		$ 402
Less: accumulated depreciation	(63)		(42)
Property and equipment, net	417		360
Depreciation expense	21	$ 3
Computer equipment
Property and Equipment, net
Property and equipment	284		262
Manufacturing equipment
Property and Equipment, net
Property and equipment	117		101
Furniture and Fixtures [Member]
Property and Equipment, net
Property and equipment	$ 79		$ 39

Accrued Expenses (Details)

Accrued Expenses (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Accrued Expenses
Research and development expenses	$ 178	$ 123
Employee-related expenses	310
Licensing fees		250
Vixen contract payable.	100
Professional fees	281	283
Other	52	89
Accrued expenses, total	$ 921	$ 745

Stockholders' Equity - Preferre

Stockholders' Equity - Preferred and Common Stock (Details)	3 Months Ended
	Mar. 31, 2016USD ($)Vote$ / sharesshares	Dec. 31, 2015$ / sharesshares
Stockholders' Equity (Deficit)
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares outstanding	0	0
Common stock shares authorized	100,000,000	100,000,000
Common stock par value (in dollars per share) | $ / shares	$ 0.00001	$ 0.00001
Number of votes per share | Vote	1
Dividends declared | $	$ 0

Stock-Based Awards (Details)

Stock-Based Awards (Details) - USD ($) $ / shares in Units, $ in Thousands	Jan. 01, 2016	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015	Sep. 15, 2015
Stock-based awards
Options granted (in shares)		68,500
Number of Shares
Number of Shares, beginning balance	1,738,524	1,738,524
Number of Shares, Granted		68,500
Number of Shares, ending balance		1,807,024		1,738,524
Number of Shares, Options vested and expected to vest		1,807,024
Number of Shares, Options exercisable		180,422
Weighted Average Exercise Price
Weighted Average Exercise Price, beginning balance (in dollars per share)	$ 13.23	$ 13.23
Weighted Average Exercise Price, Granted (in dollars per share)		20.28
Weighted Average Exercise Price, ending balance (in dollars per share)		13.50		$ 13.23
Weighted Average Exercise Price, Options vested and expected to vest (in dollars per share)		13.50
Weighted Average Exercise Price, Options exercisable (in dollars per share)		$ 1.27
Weighted Average Remaining Contractual Term
Weighted Average Remaining Contractual Term (in years)		9 years 3 months 11 days		9 years 6 months 4 days
Weighted Average Remaining Contractual Term, Options vested and expected to vest (in years)		9 years 3 months 11 days
Weighted Average Remaining Contractual Term, Options exercisable (in years)		8 years 5 months 27 days
Aggregate Intrinsic Value
Aggregate Intrinsic Value		$ 14,892		$ 24,722
Aggregate Intrinsic Value, Options vested and expected to vest		14,892
Aggregate Intrinsic Value, Options exercisable		$ 3,189
Weighted average grant-date fair value of stock options granted (in dollars per share)		$ 16.75
Employee, director and consultant stock options
Stock Option Valuation
Risk-free interest rate (as a percent)		1.49%
Expected term (in years)		7 years 3 months 18 days
Expected volatility (as a percent)		99.97%
Expected dividend yield (as a percent)		0.00%
Expected forfeiture rate (as a percent)		0.00%	0.00%
2012 Equity Compensation Plan
Stock-based awards
Number of shares available for grant		0
Number of Shares
Number of Shares, beginning balance	1,140,524	1,140,524
Number of Shares, ending balance		1,140,524		1,140,524
2012 Equity Compensation Plan | Employee, director and consultant stock options
Stock-based awards
Term of award (in years)		10 years
Vesting period (in years)		4 years
2015 Equity Incentive Plan
Stock-based awards
Number of shares available for grant		2,856,695
Number of shares authorized					2,784,395
Percentage increase to shares available for grant from common outstanding as of preceding December 31 (as a percent)					4.00%
Additional shares available	806,300

Stock-Based Awards - RSUs (Deta

Stock-Based Awards - RSUs (Details)	3 Months Ended
	Mar. 31, 2016$ / sharesshares
Weighted Average Grant Date Fair Value Per Share
Weighted average period unrecognized stock-based compensation cost to be recognized (in years)	3 years 3 months 15 days
2015 Equity Incentive Plan | Restricted Stock Units (RSUs) [Member]
RSU Activity
Units outstanding, beginning of period | shares	53,800
Granted | shares	13,700
Units outstanding, end of period | shares	67,500
Weighted Average Grant Date Fair Value Per Share
Weighted average grant date fair value, beginning balance (in dollars per share) | $ / shares	$ 28.68
Granted, estimated grant-date fair value (in dollars per share) | $ / shares	20.28
Weighted average grant date fair value, ending balance (in dollars per share) | $ / shares	$ 26.98

Stock-Based Awards - Compensati

Stock-Based Awards - Compensation (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Stock-based compensation expense
Stock-based compensation expense	$ 1,222	$ 43
Unrecognized stock-based compensation cost	$ 18,807
Weighted average period unrecognized stock-based compensation cost to be recognized (in years)	3 years 3 months 15 days
Research and development expense.
Stock-based compensation expense
Stock-based compensation expense	$ 421	13
General and administrative expense.
Stock-based compensation expense
Stock-based compensation expense	$ 801	$ 30

Net Loss per Share (Details)

Net Loss per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Numerator:
Net loss	$ (13,039)	$ (2,623)
Accretion of convertible preferred stock to redemption value		(657)
Net loss attributable to common stockholders	$ (13,039)	$ (3,280)
Denominator:
Weighted average shares of common stock outstanding (in shares)	20,171,518	2,730,427
Less: Weighted average shares of unvested restricted common stock outstanding (in shares)		(695,577)
Weighted average common shares outstanding used in calculating net loss per share attributable to common stockholders, basic and diluted (in shares)	20,171,518	2,034,850
Net loss per share attributable to common stockholders, basic and diluted (in dollars per share)	$ (0.65)	$ (1.61)

Net Loss per Share - Anti-dilut

Net Loss per Share - Anti-dilution (Details) - shares	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential common shares excluded from the calculation of diluted net loss per share attributable to common stockholders	1,874,524	9,064,792
Employee, director and consultant stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential common shares excluded from the calculation of diluted net loss per share attributable to common stockholders	1,807,024	500,262
Restricted Stock Units (RSUs) [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential common shares excluded from the calculation of diluted net loss per share attributable to common stockholders	67,500
Restricted common stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential common shares excluded from the calculation of diluted net loss per share attributable to common stockholders		639,611
Convertible preferred stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential common shares excluded from the calculation of diluted net loss per share attributable to common stockholders		7,924,919

Commitments and Contingencies40

Commitments and Contingencies (Details) - Director - Direct sublease agreement - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Lease
Expenses incurred under related party transactions	$ 52	$ 26
Future minimum lease payments under the sublease
2,016	185
2,017	263
2,018	268
2,019	251
Total	$ 967

Related Party Transactions (Det

Related Party Transactions (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Director | Direct sublease agreement
Related Party Transactions
Expenses incurred under related party transactions	$ 52	$ 26
Certain officers | Services agreement
Related Party Transactions
Expenses incurred under related party transactions	140	123
Amounts due from (to) related party	(29)
Other revenue earned from related party transactions	36	112
Payments made for related party transactions	58	15
Certain officers | Services agreement | General and administrative expense.
Related Party Transactions
Net expenses (revenues) from related party transactions	64	75
Certain officers | Services agreement | Research and development expense.
Related Party Transactions
Net expenses (revenues) from related party transactions	$ (40)	$ (64)

Agreements Related to Intelle42

Agreements Related to Intellectual Property (Details) $ in Thousands	Mar. 24, 2016USD ($)installmentitemshares	Mar. 31, 2016USD ($)	Mar. 31, 2015USD ($)
License Agreement
Upfront payment recorded as research and development expense		$ 9,535	$ 1,737
Assignment Agreement and Finder's Services Agreement [Member] | A-101
License Agreement
Maximum aggregate payments owed upon achievement of specified pre-commercialization milestones		1,000
Maximum additional payments owed upon achievement of second set of development milestones		$ 4,500
Term of Agreeement, Minimum		15 years
Assignment Agreement and Finder's Services Agreement [Member] | A-101 | General and administrative expense.
License Agreement
Milestone payment		$ 300
Stock Purchase Agreement [Member]
License Agreement
Maximum aggregate payments owed upon achievement of specified pre-commercialization milestones	$ 18,000
Maximum additional payments owed upon achievement of second set of development milestones	22,500
Upfront payment recorded as research and development expense	$ 600
Stock Issued During Period, Shares, Purchase of Assets | shares	159,420
Amount Of Fixed Annual Payment	$ 100
Number Of Products | item	3
Stock Issued During Period, Value, Purchase of Assets	$ 2,355
Number Of Payments | installment	6
Commercial License Agreement
License Agreement
Maximum additional payments owed upon achievement of second set of development milestones	$ 11,600
Amount Of Fixed Annual Payment	$ 10

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Income Taxes
Federal income tax benefit	$ 0	$ 0
State income tax benefit	$ 0	$ 0