CoLucid Pharmaceuticals (CLCD) 10-Q 9 Nov 16 2016 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2016	Nov. 08, 2016
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2016
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	Q3
Trading Symbol	CLCD
Entity Registrant Name	COLUCID PHARMACEUTICALS, INC.
Entity Central Index Key	1,348,649
Current Fiscal Year End Date	--12-31
Entity Filer Category	Smaller Reporting Company
Entity Common Stock, Shares Outstanding		19,246,737

Condensed Balance Sheets (Unaud

Condensed Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 83,540	$ 27,978
Available for sale securities (less than 1 year)	16,641	36,530
Prepaid expenses and other current assets	769	809
Total current assets	100,950	65,317
Other assets	21	21
Total assets	100,971	65,338
Current liabilities:
Accounts payable	4,151	1,649
Accrued expenses	4,782	3,780
Total current liabilities	8,933	5,429
Deferred revenue	1,500	1,500
Total liabilities	10,433	6,929
Commitments and contingencies (note 7)
Stockholders’ equity
Common stock, $0.001 par value; 270,000,000 shares authorized; 19,236,480 and 15,153,135 shares issued and outstanding as of September 30, 2016 and December 31, 2015, respectively	19	15
Additional paid-in capital	219,601	145,532
Accumulated other comprehensive income (loss)	7	(43)
Accumulated deficit	(129,089)	(87,095)
Total stockholders’ equity	90,538	58,409
Total liabilities and stockholders’ equity	$ 100,971	$ 65,338

Condensed Balance Sheets (Paren

Condensed Balance Sheets (Parenthetical) (Unaudited) - $ / shares	Sep. 30, 2016	Dec. 31, 2015
Statement Of Financial Position [Abstract]
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	270,000,000	270,000,000
Common stock, shares issued	19,236,480	15,153,135
Common stock, shares outstanding	19,236,480	15,153,135

Condensed Statements of Operati

Condensed Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Operating expenses:
Research and development	$ 10,509	$ 5,777	$ 35,709	$ 13,534
General and administrative	2,211	3,219	6,491	6,049
Total operating expenses	12,720	8,996	42,200	19,583
Loss from operations	(12,720)	(8,996)	(42,200)	(19,583)
Other income:
Interest income, net	63	46	206	73
Total other income, net	63	46	206	73
Net loss before income tax expense	(12,657)	(8,950)	(41,994)	(19,510)
Net loss	(12,657)	(8,950)	(41,994)	(19,510)
Gain on extinguishment of convertible stock				4,798
Accretion of redeemable preferred stock				(12,553)
Net loss attributable to common stockholders	$ (12,657)	$ (8,950)	$ (41,994)	$ (27,265)
Per common share information:
Net loss attributable to common stockholders, basic and diluted	$ (0.79)	$ (0.59)	$ (2.70)	$ (3.27)
Weighted-average common shares outstanding, basic and diluted	16,057,462	15,153,135	15,543,386	8,336,147
Comprehensive loss:
Net loss	$ (12,657)	$ (8,950)	$ (41,994)	$ (19,510)
Other comprehensive loss:
Unrealized (loss) gain on available for sale securities	(13)	(9)	7	(9)
Comprehensive loss	$ (12,670)	$ (8,959)	$ (41,987)	$ (19,519)

Condensed Statements of Cash Fl

Condensed Statements of Cash Flows (Unaudited) - USD ($)	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Cash flows from operating activities:
Net loss	$ (41,994,000)	$ (19,510,000)
Adjustments to reconcile net loss to net cash used in operating activities:
Amortization of discount on investments	436,000	81,000
Stock-based compensation	2,669,000	3,126,000
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	40,000	(1,510,000)
Other assets		(21,000)
Accounts payable	2,502,000	2,322,000
Accrued expenses	1,002,000	2,927,000
Net cash used in operating activities	(35,345,000)	(12,585,000)
Cash flows from investing activities:
Purchases of available for sale securities	(16,828,000)	(38,169,000)
Maturities of available for sale securities	36,331,000
Net cash provided by (used in) investing activities	19,503,000	(38,169,000)
Cash flows from financing activities:
Proceeds from issuance of common stock, net of cost of issuance	69,920,000	49,816,000
Proceeds from the exercise of common stock options	1,431,000	90,000
Shares repurchased for tax withholdings for vested restricted stock awards	(95,000)
Proceeds from employee stock purchase plan	148,000
Net cash provided by financing activities	71,404,000	86,569,000
Net increase in cash and cash equivalents	55,562,000	35,815,000
Cash and cash equivalents as of beginning of period	27,978,000	204,000
Cash and cash equivalents as of end of period	83,540,000
Supplemental schedule of non-cash financing activities
Public offering costs included in accounts payable and accrued expenses	$ 272,000
Conversion of convertible notes payable to preferred stock		200,000
Gain on extinguishment of preferred stock		(4,798,000)
Accretion of redeemable preferred stock		12,553,000
Conversion of preferred stock to common stock		94,897,000
Series C Redeemable Convertible Preferred Stock [Member]
Cash flows from financing activities:
Proceeds from issuance of Series C redeemable convertible preferred stock, net of costs of issuance of $200		$ 36,663,000

Condensed Statements of Cash F6

Condensed Statements of Cash Flows (Parenthetical) (Unaudited) $ in Thousands	9 Months Ended
	Sep. 30, 2016USD ($)
Series C Redeemable Convertible Preferred Stock [Member]
Stock issuance costs	$ 200

Nature of Operations

Nature of Operations	9 Months Ended
	Sep. 30, 2016
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Nature of Operations	1. Nature of Operations Discussion of the Business CoLucid Pharmaceuticals, Inc. (the “Company”) is a Phase 3 clinical-stage biopharmaceutical company that is developing an innovative and proprietary small molecule for the acute treatment of migraine. The Company’s product candidates utilize the first new mechanism of action under development in the last twenty years that could address the unmet needs of migraine patients, including those with cardiovascular risk factors or stable cardiovascular disease and those who are dissatisfied with existing therapies. Lasmiditan, the Company’s lead product candidate, is an oral tablet for the acute treatment of migraine in adults which is not expected to have the clinical limitations associated with the most commonly used therapies. The Company is also developing intravenous lasmiditan (“IV lasmiditan”) for the acute treatment of headache pain associated with migraine in adults in emergency room and other urgent care settings, another significant unmet medical need. The Company has completed its first pivotal Phase 3 randomized, double-blind, placebo-controlled clinical trial of lasmiditan, SAMURAI, under a special protocol assessment (“SPA”) agreement with the U.S. Food and Drug Administration (“FDA”). In September 2016, the Company announced that the SAMURAI study achieved both the primary and key secondary efficacy endpoints with statistical significance (p < 0.001). The Company has a SPA agreement with the FDA for its second pivotal Phase 3 clinical trial of lasmiditan, SPARTAN, which began enrollment in the second quarter of 2016 with top-line data expected to be released in the second half of 2017. The Company is also conducting its long-term, open-label study of lasmiditan, GLADIATOR. In September 2016 the Company announced a follow-on public offering of common stock from which the Company received approximately $69.9 million in net proceeds. The Company believes it has sufficient cash, cash equivalents and available for sale securities to enable it to fund the remainder of SPARTAN, a substantial portion of GLADIATOR and the submission of a New Drug Application, or NDA, to the FDA. The Company also estimates that such funds will support its operating expenses and capital expenditure requirements through at least the second quarter of 2018. The Company has never been profitable and has incurred net losses in each year since inception. The Company’s net losses attributable to common stockholders were $38.5 million and $3.0 million for the years ended December 31, 2015 and 2014, respectively, and $12.7 million and $42.0 million for the three and nine months ended September 30, 2016, respectively. As of September 30, 2016, the Company’s accumulated deficit was $129.1 million. These net losses resulted primarily from research and development programs, including preclinical development activities and clinical trials, and general and administrative costs associated with operations. The Company expects to continue to incur significant expenses and increasing operating losses for at least the next several years. These net losses and negative operating cash flows have had, and will continue to have, an adverse effect on stockholders’ equity and working capital. Because of the numerous risks and uncertainties associated with pharmaceutical product development, the Company is unable to accurately predict the timing or amount of increased expenses or when, or if, it will be able to achieve or maintain profitability. The Company was incorporated on August 31, 2005 in the state of Delaware, with its current headquarters at 222 Third Street, Suite 1320 in Cambridge, Massachusetts. Initial Public Offering In connection with preparing for its initial public offering (“IPO”), the Company’s Board of Directors and stockholders approved a one-for-40.7 reverse stock split of the Company’s common stock. The reverse stock split became effective in April 2015. All share and per share amounts in these condensed interim financial statements and notes thereto have been retroactively adjusted for all periods presented to give effect to this reverse stock split, including reclassifying an amount equal to the reduction in par value of common stock to additional paid-in capital. On May 11, 2015, the Company closed an IPO of its common stock, which resulted in the sale of 5,500,000 shares of its common stock at a public offering price of $10.00 per share. The Company received net proceeds from the IPO of approximately $49.8 million, after deducting underwriting discounts and approximately $1.3 million of expenses paid by the Company. In connection with the closing of the IPO, all of the Company’s outstanding redeemable convertible preferred stock automatically converted to common stock on May 5, 2015, resulting in an additional 9,489,659 shares of common stock of the Company becoming outstanding. At September 30, 2016, and December 31, 2015, the Company did not have any redeemable convertible preferred stock issued or outstanding. The significant increase in common stock outstanding in connection with the IPO impacts the year-over-year comparability of the Company’s net loss per share calculations. Follow-on Public Offering On September 14, 2016, the Company closed a follow-on public offering of shares of its common stock, which resulted in the sale of 3,737,500 shares of common stock at a price to the public of $20.00 per share. The aggregate net proceeds received by the Company from the offering were approximately $69.9 million, net of underwriting discounts and commissions of approximately $4.6 million and approximately $0.3 million of offering expenses paid by the Company.

Summary of Significant Accounti

Summary of Significant Accounting Policies and Basis of Presentation	9 Months Ended
	Sep. 30, 2016
Accounting Policies [Abstract]
Summary of Significant Accounting Policies and Basis of Presentation	2. Summary of Significant Accounting Policies and Basis of Presentation Basis of Presentation The accompanying unaudited condensed financial statements of the Company have been prepared in accordance with accounting principles generally accepted in the United States (“GAAP”) for interim financial reporting and pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”). Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements. In the opinion of management, all adjustments (including those which are normal and recurring) considered necessary for a fair presentation of the interim financial information have been included. When preparing financial statements in conformity with GAAP, the Company must make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues, expenses and related disclosures at the date of the financial statements. Actual results could differ from those estimates. Additionally, operating results for the three and nine months ended September 30, 2016 are not necessarily indicative of the results that may be expected for any other interim period or for the fiscal year ending December 31, 2016. The condensed interim financial statements should be read in conjunction with the audited financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2015 filed with the SEC. Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts in the financial statements and accompanying notes. Estimates are used in the following areas, among others: stock-based compensation expense, accrued expenses and income taxes. Actual results could materially differ from those estimates. Cash and Cash Equivalents Cash and cash equivalents consist of all cash on hand, deposits and funds invested in available for sale securities with original maturities of three months or less at the time of purchase. At September 30, 2016, the Company’s cash was primarily in money market funds. The Company may maintain balances with its banks in excess of federally insured limits. Available for Sale Securities Management determines the appropriate classification of securities at the time of purchase and reevaluates such designation as of each balance sheet date. Currently, the Company classifies all securities as available for sale which are included in current and non-current assets. The Company carries available for sale securities at fair value based on current market value. The Company conducts periodic reviews to identify and evaluate each investment that has an unrealized loss, in accordance with the meaning of other-than-temporary impairment and its application to certain investments. When assessing whether a decline in the fair value of a security is other-than-temporary, the Company considers the fair market value of the security, the duration of the security’s decline, and prospects for the underlying business. Based on these considerations, the Company did not identify any other-than-temporary impairments at September 30, 2016. Unrealized losses on available for sale securities that are determined to be temporary, and not related to credit loss, are recorded, net of tax, in accumulated other comprehensive loss, a component of stockholders’ equity. The amortized cost of debt securities in this category reflects amortization of premiums and accretion of discounts to maturity computed under the effective interest method. The Company includes this amortization in the caption “Interest income, net” within the Condensed Statements of Operations and Comprehensive Loss. The Company also includes in interest income, net, realized gains and losses and declines in value determined to be other than temporary. The Company bases the cost of securities sold upon the specific identification method, and includes interest and dividends on securities in interest income. Concentration of Credit Risk Financial instruments, which potentially subject the Company to significant concentration of credit risk, consist primarily of cash, cash equivalents, corporate debt securities, commercial paper and U.S. Treasuries. The Company maintains deposits in federally insured institutions in excess of federally insured limits. The Company has not experienced any losses in such accounts and management believes that the Company is not exposed to significant credit risk due to the financial position of the depository institutions in which those deposits are held. Substantially all of the Company’s available for sale securities are with companies that management believes to be of high-credit quality with short-term credit ratings of at least A-1/P-1 or better by Standard and Poor’s and Moody’s Investor Service at the time of purchase. The Company has no financial instruments with off-balance sheet risk of loss. Distribution and Supply Agreement On October 23, 2013, the Company entered into a distribution and supply agreement with Ildong Pharmaceutical Co., Ltd. (“Ildong”) for lasmiditan in the Republic of Korea, Taiwan, Singapore, Malaysia, Indonesia, Philippines, Thailand, Myanmar and Vietnam, which is referred to as the territory. During the term of the agreement, the Company must use commercially reasonable efforts to supply Ildong with the amount of lasmiditan that it requires. Under the terms of the agreement, the Company received an upfront payment of $1.5 million as consideration for the Company granting Ildong exclusive rights to develop and commercialize lasmiditan in the territory as well as the Company’s agreement to provide lasmiditan to Ildong in the future for a reduced purchase price. This $1.5 million upfront payment is reflected in deferred revenue as of September 30, 2016 and December 31, 2015, and will be recognized as revenue in the event the Company sells lasmiditan to Ildong for commercial sale. In the event the Company has no further obligations under this agreement prior to the date regulatory approval is obtained, if at all, the Company will recognize this upfront payment as revenue at that time since lasmiditan would not have been sold and delivered to Ildong for commercial sale. The Company also has the potential to receive aggregate potential future milestone payments from Ildong of up to $3.5 million, including (i) $1 million upon the submission of a new drug application to the FDA or a submission of an equivalent regulatory filing to the European Medicines Agency in the European Union; (ii) $1.5 million upon obtaining approval of lasmiditan by the FDA or the European Medicines Agency; and (iii) $1 million upon obtaining approval of lasmiditan in the Republic of Korea. The Company will supply Ildong with lasmiditan for use in clinical trials in the territory, for which Ildong will pay to the Company an amount equal to the Company’s fully burdened manufacturing cost (or the Company’s fully burdened cost of goods if lasmiditan is obtained from a third-party supplier for such trials), plus 5% per tablet of lasmiditan. If approved in the territory, the Company will also supply Ildong with lasmiditan for sale in the territory, for which Ildong will pay to the Company a purchase price per unit calculated as a percentage (ranging from 31.5% to 36.5%) of the net sales of lasmiditan in the territory. Ildong will be responsible for the costs and activities related to development and regulatory approvals in the territory as part of the global development plan under the agreement. The agreement terminates upon the later of the expiration of the Company’s patents in the territory or 15 years after the first commercialization of lasmiditan, and is subject to certain renewal rights. The agreement may be terminated by mutual agreement or by either party in the case of uncured material breach or bankruptcy. The Company has the right to terminate if Ildong challenges any of the Company’s patents or fails to adequately commercialize lasmiditan in the territory. Stock-Based Compensation The Company recognizes compensation cost relating to stock-based payment transactions in operating results using a fair-value measurement method, in accordance with Accounting Standards Codification (“ASC”) Topic 718, Compensation-Stock Compensation Grants to non-employees are accounted for in accordance with ASC Topic 505-50, Equity-Based Payments to Non-Employees Compensation cost associated with restricted stock unit (“RSU”) grants is based on the fair value of the RSUs granted (which is the closing price of the Company’s common stock on the date of grant multiplied by the number of RSUs in the grant), adjusted for the expected forfeiture rate. Income Taxes The Company accounts for income taxes under the liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements. Under this method, deferred tax assets and liabilities are determined on the basis of the differences between the financial statements and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in income in the period that includes the enactment date. The Company recognizes net deferred tax assets to the extent that the Company believes these assets are more likely than not to be realized. In making such a determination, management considers all available positive and negative evidence, including future reversals of existing temporary differences, projected future taxable income, tax-planning strategies, and result of recent operations. If management determines that the Company would be able to realize its deferred tax assets in the future, in excess of its net recorded amount, management would make an adjustment to the deferred tax asset valuation allowance, which would reduce the provision for income taxes. The Company records uncertain tax positions on the basis of a two-step process whereby (1) management determines whether it is more likely than not that the tax positions will be sustained on the basis of the technical merits of the position and (2) for those tax positions that meet the more likely than not recognition threshold, management recognizes the largest amount of tax benefit that is more than 50% likely to be realized upon ultimate settlement with the related tax authority. The Company recognizes interest and penalties related to unrecognized tax benefits within income tax expense. Any accrued interest and penalties are included within the related tax liability. Accrued Research and Development Expenses As part of the process of preparing its financial statements, the Company is required to estimate its accrued research and development expenses. This process involves reviewing open contracts and purchase orders, communicating with the Company’s personnel to identify services that have been performed on the Company’s behalf and estimating the level of service performed and the associated cost incurred for the service when the Company has not yet been invoiced or otherwise notified of the actual cost. The majority of the Company’s service providers invoice the Company monthly in arrears for services performed. The Company makes estimates of its accrued expenses as of each balance sheet date in its financial statements based on facts and circumstances known to it at that time. The Company confirms the accuracy of its estimates with the service providers and makes adjustments if necessary. Examples of estimated accrued research and development expenses include expenses for: • Contract Research Organizations (“CRO”) in connection with clinical studies; • investigative sites in connection with clinical studies; • vendors in connection with preclinical development activities; and • vendors related to product manufacturing, development and distribution of clinical materials. The Company bases its accrued expenses related to clinical studies on its estimates of the services received and efforts expended pursuant to contracts with its CRO that conducts and manages clinical studies on the Company’s behalf. The financial terms of these agreements are subject to negotiation, vary from contract to contract and may result in uneven payment flows. The scope of services under these contracts can be modified and some of the agreements may be cancelled by either party upon written notice. There may be instances in which payments made to the Company’s vendors will exceed the level of services provided and result in a prepayment of the clinical expense. Payments under some of these contracts with CROs depend on factors such as the successful enrollment of subjects and the completion of clinical study milestones. In accruing service fees, the Company estimates the time period over which services will be performed and the level of effort to be expended in each period. If the actual timing of the performance of services or the level of effort varies from the Company’s estimate, the Company adjusts the accrual or prepaid expense accordingly. Although the Company does not expect its estimates to be materially different from amounts actually incurred, if its estimates of the status and timing of services performed differ from the actual status and timing of services performed, the Company may report amounts that are too high or too low in any particular period. To date, there have been no material differences between its estimates and the amount actually incurred. Net Loss Per Common Share Basic net loss per common share is calculated by dividing net loss attributable to common stockholders by the weighted-average number of common shares outstanding during the period, without consideration for common stock equivalents or unvested restricted stock units. Diluted net loss per share is computed by dividing the net loss attributable to common stockholders by the weighted-average number of common share equivalents outstanding for the period determined using the treasury-stock method. For purposes of this calculation, convertible preferred stock, stock options, RSUs and shares to be purchased under the ESPP are considered to be common stock equivalents and are only included in the calculation of diluted net loss per share when their effect is dilutive. Subsequent Events The Company has evaluated all subsequent events through the date of this filing.

Available for Sale Securities

Available for Sale Securities	9 Months Ended
	Sep. 30, 2016
Investments Debt And Equity Securities [Abstract]
Available for Sale Securities	3. Available for Sale Securities The following table summarizes the available for sale securities held by the Company at September 30, 2016 and December 31, 2015: Gross Unrealized Description Amortized Cost Gains / (Losses) Fair Value (in thousands) September 30, 2016 Available for sale securities: Corporate debt securities $ 3,810 $ (1 ) $ 3,809 Commercial paper 3,798 — 3,798 U.S. Government debt securities 9,026 8 9,034 Total available for sale securities $ 16,634 $ 7 $ 16,641 December 31, 2015 Available for sale securities: Corporate debt securities $ 36,573 (43 ) 36,530 Total available for sale securities $ 36,573 $ (43 ) $ 36,530 The estimated fair value of the Company’s available for sale securities at September 30, 2016 by contractual maturity, was as follows: September 30, 2016 (in thousands) Due in one year or less $ 16,641 Due after one year — Total available for securities $ 16,641

Fair Value of Financial Instrum

Fair Value of Financial Instruments	9 Months Ended
	Sep. 30, 2016
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	4. Fair Value of Financial Instruments The Company determines the fair market values of its financial instruments based on the fair value hierarchy, which requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. Fair value measurements are classified and disclosed in one of the following three categories: Level 1 inputs Quoted prices in active markets for identical assets or liabilities that the Company has the ability to access at the measurement date. Level 2 inputs Observable inputs other than Level 1 prices such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. Level 3 inputs Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. Transfers are calculated on values as of the transfer date. There were no transfers between Levels 1, 2 and 3 during the three or nine months ended September 30, 2016 or during 2015. The Company had no liabilities classified as Level 3 that are measured by management at fair value as of September 30, 2016 or December 31, 2015. The Company’s financial instruments consist principally of cash and cash equivalents, available for sale securities, accounts payable and accrued liabilities. Financial instruments measured at fair value are classified below based on the three fair value hierarchy tiers described above: Significant Quoted prices other Significant in active observable unobservable markets inputs inputs Total (Level 1) (Level 2) (Level 3) (in thousands) September 30, 2016 Assets Cash and money market $ 83,540 $ 83,540 $ — $ — Commercial paper 3,798 — 3,798 — Corporate debt securities 3,809 — 3,809 — U.S. Government debt securities 9,034 — 9,034 — Total $ 100,181 $ 83,540 $ 16,641 $ — December 31, 2015 Assets Cash and money market $ 27,978 $ 27,978 $ — $ — Corporate debt securities 36,530 — 36,530 — Total $ 64,508 $ 27,978 $ 36,530 $ — The carrying values of accounts payable and accrued liabilities approximate their fair values due to the short maturity of these instruments. The fair values of shares of Series A, Series B, and Series C redeemable convertible preferred stock that were outstanding prior to May 5, 2015 were determined using probability-weighted valuation methodologies based on recent market activity. Inputs into the valuation models included the Company’s Series C redeemable convertible preferred stock offering, recent initial public offerings of similar sized life sciences companies and assumptions concerning future financing alternatives. The valuation model was complex as it required numerous assumptions relating to potential future outcomes. On May 5, 2015, the fair value of Series A, Series B, and Series C redeemable convertible preferred stock, which was based on the IPO price of the Company’s common stock, was determined using Level 2 inputs.

Accrued liabilities

Accrued liabilities	9 Months Ended
	Sep. 30, 2016
Payables And Accruals [Abstract]
Accrued liabilities	5. Accrued liabilities Accrued expenses consist of the following: September 30, December 31, 2016 2015 (in thousands) Payroll and employee-related costs $ 579 $ 669 Clinical trial costs 3,028 1,933 Research and development costs 650 707 Professional fees 432 266 Excise tax payable 63 126 Other 30 79 $ 4,782 $ 3,780

Notes Payable

Notes Payable	9 Months Ended
	Sep. 30, 2016
Debt Disclosure [Abstract]
Notes Payable	6. Notes Payable In December 2014, the Company entered into a Convertible Note Purchase Agreement with certain investors to provide up to $1,000,000 in bridge loan financing. The initial closing of $200,000 was funded on December 15, 2014. The notes, which were non-interest bearing, were subject to automatic conversion in a qualified financing at the price per share at which the Company sells and issues such shares in the qualified financing. The notes were converted into Series C redeemable convertible preferred stock on January 12, 2015 (see Note 8).

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2016
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	7. Commitments and Contingencies License Agreement On February 10, 2015, the Company amended and restated its development and license agreement with Eli Lilly and Company (“Lilly”) which consolidated a number of amendments to the Company’s development and license agreement with Lilly dated December 16, 2005. Pursuant to such agreement, the Company holds a worldwide license, with the right to grant sublicenses, under certain patents and know-how owned or controlled by Lilly for lasmiditan for all human health purposes. The license is exclusive except that Lilly has retained the right to conduct research on lasmiditan and products containing lasmiditan for internal research purposes only. The term of the agreement will expire on a country-by-country basis upon expiration of the Company’s royalty obligations in such country, which occurs on the later of the tenth anniversary of the first commercial sale in such country or the expiration of the last-to-expire licensed patent in such country. Upon expiration of royalty payment provisions in a given country, the Company will have a fully paid up, perpetual, irrevocable know-how license in such country, unless the agreement is terminated earlier. Lilly may terminate the agreement for uncured material breach, in whole or on a country-by-country basis. Lilly may also terminate the agreement upon a change of control of the Company, unless the new owner agrees to be bound by the terms and conditions of the agreement. Either party may terminate the agreement upon written notice in the event of bankruptcy. The Company has the right to terminate in the case of material breach by Lilly or if the Company believes it would be commercially unreasonable to continue to develop lasmiditan. Under the agreement, the Company is also responsible for and has control over the filing and prosecuting of patent applications and maintaining patents which cover making, using or selling lasmiditan under the agreement. In the event the Company decides to allow any licensed patent to lapse, Lilly may assume the responsibility for the patent and the Company will surrender its rights in the relevant affected countries. The Company has the first right (but not the obligation) to enforce these patent rights, and Lilly has agreed to cooperate and assist the Company in matters regarding infringement as well as patent term extensions and certifications. During the term of the agreement, the Company is required to use reasonable commercial efforts to develop and obtain regulatory approvals for selling products containing lasmiditan in all major markets, which include Japan, France, Germany, Italy, Spain, the United Kingdom and the United States. If the Company obtains regulatory approval for one of its product candidates containing lasmiditan, the Company is required to use reasonable commercial efforts to commercialize the product in that country. If the Company does not satisfy this obligation, Lilly may terminate the agreement. Upon execution of the original agreement in 2005, the Company paid an upfront license fee to Lilly of $1 million and issued to Lilly shares of its common stock, both of which were expensed. Upon achievement of certain regulatory and/or sales milestones with respect to products containing lasmiditan, the Company will be obligated to make future payments to Lilly of up to $32 million for the first indication and up to $3 million for each subsequent indication. In addition, the Company will be obligated to pay Lilly royalties of between 8% and 11% (subject to downward adjustment in certain circumstances) on net sales of products containing lasmiditan. None of the Company’s upfront or milestone payments are creditable against its royalty obligations. Lease Agreement On September 15, 2015, the Company entered into an agreement with American Twine Limited Partnership for the lease of its principal office space in Cambridge, Massachusetts. The duration of the lease agreement is two years beginning September 15, 2015, with a total estimated rent expense of approximately $258,000 over the life of the agreement. The rent expense for the year ended December 31, 2015 was approximately $83,000 for the previously leased office in Burlington, Massachusetts and the current facility and the anticipated rent payment is approximately $136,000 for 2016 and $92,000 for 2017. In the first nine months of 2016, the Company paid approximately $103,000 in rent.

Issuance of Preferred Stock

Issuance of Preferred Stock	9 Months Ended
	Sep. 30, 2016
Equity [Abstract]
Issuance of Preferred Stock	8. Issuance of Preferred Stock On January 12, 2015, the Company issued 4,344,567 shares of Series C redeemable convertible preferred stock for $36,900,000 in cash and the conversion of $200,000 of convertible debt. The Series C redeemable convertible preferred stock contained dividend and liquidation preferences similar to the Series A and Series B convertible preferred stock. As an inducement for holders of the Company’s Series A and Series B convertible preferred stock to participate in the Series C financing and in exchange for a waiver of certain anti-dilution provisions, the Company also issued 1,426,353 shares of Series A convertible preferred stock and 2,647,102 shares of Series B convertible preferred stock. The Company has determined that the modification of the Series A and Series B convertible preferred stock was sufficiently substantial to treat the additional issuances as an extinguishment of the existing Series A and Series B convertible preferred stock. In accordance with the Financial Accounting Standards Board (“FASB”) ASC 260-10, Earnings Per Share Effective with the issuance of the Series C redeemable convertible preferred stock, all of the Company’s Series A, Series B and Series C preferred stock became redeemable five years after the issuance of the Series C redeemable convertible preferred stock at the option of the Series C preferred stockholders. The Company accreted the carrying value of its Series A and Series B convertible preferred stock and its Series C redeemable convertible preferred stock to its estimate of fair value (i.e., redemption value) at

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 30, 2016
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-Based Compensation	9. Stock-Based Compensation The Company accounts for its stock-based compensation awards in accordance with ASC 718. ASC 718 requires all stock-based payments to employees, including grants of employee stock options, restricted stock units, or RSUs, and modifications to existing stock awards, to be recognized in the statement of operations and comprehensive loss based on their fair values. The Company accounts for stock-based awards to non-employees in accordance with ASC 505-50, which requires the fair value of the award to be re-measured at fair value until a performance commitment is reached or counterparty performance is complete. The Company’s outstanding stock-based awards are comprised of stock options and restricted stock units. The Company estimates the fair value of options granted using the Black-Scholes option pricing model. Stock Option Plans During February 2006, the Company adopted the CoLucid Pharmaceuticals, Inc. Equity Incentive Plan (the “2006 Plan”). After the effective date of the 2015 Plan (defined below), no additional awards have been or will be granted under the 2006 Plan. Eligible plan participants included employees, directors and consultants. The board of directors determined the exercise price, term, and vesting provision of all options at their grant date. On April 16, 2015, the board of directors adopted the CoLucid Pharmaceuticals, Inc. 2015 Equity Incentive Plan (the “2015 Plan”), which was approved by the stockholders on the same day. There were a total 1,819,100 shares of the Company’s common stock initially reserved for issuance pursuant to the 2015 Plan. The 2015 Plan allows for the granting of stock options, stock appreciation rights, restricted stock, unrestricted stock, stock units and other awards convertible into or otherwise based on shares of common stock. The Company’s employees, officers, directors and consultants and advisors are eligible to receive awards under the 2015 Plan. The 2015 Plan provides that the number of shares reserved and available for issuance under the 2015 Plan will automatically increase annually on January 1 of each calendar year by an amount equal to the lesser of: a) six percent (6%) of the number of common shares of stock outstanding as of December 31 of the immediate preceding calendar year, or b) 1,200,000 shares, provided, however, that the board of directors may determine that any annual increase be a lesser number. In addition, all awards granted under the 2006 Plan or the 2015 Plan that are forfeited, expire, are cancelled or otherwise not issued will again become available under the 2015 Plan. Effective January 1, 2016, 687,312 shares were added to the 2015 Plan, as available for issuance thereunder, pursuant to the automatic increase feature of the 2015 Plan. As of September 30, 2016, 527,812 shares were available for future grant under the 2015 Plan. The fair value of the stock options granted are estimated on the date of grant using all relevant information, including application of the Black-Scholes option-pricing model. When applying the Black-Scholes option-pricing model to compute stock-based compensation, the Company assumed the following for the nine months ended September 30, 2016: risk-free rate of return of 0.5% to 2.1%; expected average option life of 0.3 to 10.0 years; average volatility of 75.9% to 98.7%; and expected dividend rate of 0%. The risk-free rate of return was based on U.S Treasury rates. The expected average option life assumption was based upon the simplified or “plain-vanilla” method, which averages the contractual term of the options (10 years) with the vesting term (4 years) taking into consideration multiple vesting tranches. Expected volatility for the nine month period ended September 30, 2016 was based upon the historical volatility of comparable companies. The Company estimated the expected forfeiture rate of 12.4% to 14.8% based on the historical forfeiture rate of comparable companies and estimated the expected dividend rate based on its expectations that it will not pay dividends in the foreseeable future. The following summarizes the stock option activity during the period: Weighted- Weighted- average Aggregate average remaining intrinsic price contractual value Shares per share term (years) (in thousands) Outstanding at December 31, 2015 1,215,828 $ 9.34 9.4 $ 462 Granted 371,577 7.26 10 Exercised (158,404 ) 9.03 1,935 Cancelled / Expired (44,613 ) 10.00 — Outstanding at September 30, 2016 1,384,388 $ 8.79 8.8 $ 40,644 Options exercisable at September 30, 2016 460,396 $ 9.61 8.6 $ 13,142 Options vested and expected to vest as of September 30, 2016 1,227,115 $ 8.86 8.8 $ 35,944 The aggregate intrinsic value in the above table is the difference between the closing common stock price on September 30, 2016 of $38.15 per share and the option exercise price multiplied by the number of in-the-money options as of September 30, 2016. As of September 30, 2016, total unrecognized stock-based compensation expense relating to unvested employee stock options was $3.9 million. This amount is expected to be recognized over a weighted-average period of 2.6 years. The unrecognized stock option-based compensation expense as of September 30, 2015 was $5.2 million. The weighted average fair value of options granted during the three months and nine months ended September 30, 2016 was $9.62 and $7.26 per share, respectively. Restricted Stock Awards On May 5, 2015, the Company issued 360,508 restricted stock units to the Chief Executive Officer at a grant date fair value of $10.00 per share. The restricted stock units have a requisite service period of four years, whereby the award vests 50% six months after grant, 12.5% on the one-year anniversary of the grant, then ratably over the next 36 months, subject to continuous service of the employee. In March 2016 certain members of the executive team received a total of 158,000 restricted stock units. These restricted stock units have a requisite service period of four years, whereby the awards vest in a series of 48 successive equal monthly installments with the first monthly installment vesting on the grant date and the future installments vesting on the first day of each calendar month thereafter. Continued vesting is subject to continuous service of the employee. The restricted stock units that vest during a calendar year will be settled by delivery of shares of common stock on a one-for-one basis between January 1 and March 15 of the year immediately following the calendar year in which such restricted stock units vest. As of September 30, 2016, there was approximately $1.8 million of unrecognized compensation cost related to the restricted stock unit awards, which is expected to be recognized over a weighted average period of 2.9 years. The following summarizes RSU activity for the nine months ended September 30, 2016: Weighted- Aggregate average grant intrinsic date fair value value Shares per share (in thousands) Unvested balance at December 31, 2015 180,254 $ 10.00 $ 1,509 Granted 158,000 6.75 1,067 Vested (83,128 ) 9.10 Forfeited — — Outstanding at September 30, 2016 255,126 $ 8.28 $ 9,733 Vested and unsettled as of September 30, 2016 23,042 $ 6.75 $ 879 Vested and expected to vest as of September 30, 2016 247,030 $ 8.27 $ 9,424 Employee Stock Purchase Plan On April 16, 2015, the board of directors adopted the Company’s Employee Stock Purchase Plan (the “ESPP”), which was approved by the stockholders on the same day. There initially were 300,000 shares of the Company’s common stock reserved for issuance and sale pursuant to the ESPP. In addition, the ESPP provides for automatic annual increases in the number of shares available for issuance under the ESPP on January 1 of each year in an amount equal to the lesser of: (i) 1% of the total number of shares outstanding as of December 31 of the immediately preceding calendar year, or (ii) 150,000 shares, unless a lesser number of shares is otherwise determined by the Company’s board of directors. The ESPP was implemented effective December 1, 2015 and permits the Company’s employees to purchase shares of the Company’s common stock. As of September 30, 2016, there were 428,481 shares available for future purchase under the ESPP, which included the increase effective January 1, 2016 pursuant to the automatic increase feature of the ESPP. The ESPP is considered a compensatory plan with the related compensation cost expensed over the six month offering period. As of September 30, 2016, approximately $148,000 of employee payroll deductions which have been withheld since January 1, 2016 and are included in additional paid in capital in the accompanying condensed balance sheet. The compensation expense related to the ESPP for the three and nine months ended September 30, 2016 was $19,000 and $64,000, respectively. Compensation Expense Summary The Company recognized the following compensation cost related to share-based awards in the three and nine months ended Three months ended Nine months ended September 30, September 30, 2016 2015 2016 2015 (in thousands) (in thousands) Research and development $ 206 $ 177 $ 648 $ 293 General and administrative 561 1,795 2,021 2,833 Total $ 767 $ 1,972 $ 2,669 $ 3,126 Compensation expense by type of award in the three and nine months ended September 30, 2016 was as follows: Three months ended Nine months ended September 30, September 30, 2016 2015 2016 2015 (in thousands) (in thousands) Stock options $ 569 $ 1,075 $ 1,934 $ 1,671 Restricted stock units 179 897 671 1,455 Employee Stock Purchase Plan 19 — 64 — Total $ 767 $ 1,972 $ 2,669 $ 3,126

Net Loss Per Common Share

Net Loss Per Common Share	9 Months Ended
	Sep. 30, 2016
Earnings Per Share [Abstract]
Net Loss Per Common Share	10. Net Loss Per Common Share Basic net loss per common share is calculated by dividing net loss attributable to common stockholders by the weighted-average number of common shares outstanding during the period, without consideration for common stock equivalents or unvested restricted stock. Diluted net loss per share is computed by dividing the net loss attributable to common stockholders by the weighted average number of common share equivalents outstanding for the period determined using the treasury-stock method. For purposes of this calculation, convertible preferred stock, stock options, RSUs and shares to be purchased under the ESPP are considered to be common stock equivalents and are only included in the calculation of diluted net loss per share when their effect is dilutive. The following table sets forth the computation of basic and diluted net loss per share applicable to common stockholders (in thousands, except share and per share data): Three months ended Nine months ended September 30, September 30, 2016 2015 2016 2015 Numerator: Net loss $ (12,657 ) $ (8,950 ) $ (41,994 ) $ (19,510 ) Gain on extinguishment of convertible stock — — — 4,798 Accretion of redeemable convertible preferred stock — — — (12,553 ) Net loss attributable to common stockholders $ (12,657 ) $ (8,950 ) $ (41,994 ) $ (27,265 ) Denominator: Weighted average common shares outstanding - Basic and Diluted 16,057,462 15,153,135 15,543,386 8,336,147 Net loss per share attributable to common stockholders - Basic and Diluted $ (0.79 ) $ (0.59 ) $ (2.70 ) $ (3.27 ) The common stock equivalents in the table below were excluded from the calculation of diluted weighted-average shares outstanding due to their anti-dilutive effect: Three months ended Nine months ended September 30, September 30, 2016 2015 2016 2015 Convertible preferred stock — — — 3,971,137 Outstanding stock options 1,509,614 1,183,322 1,441,631 655,026 Restricted stock units 283,809 360,508 278,464 196,761 Employee Stock Purchase Plan shares 15,961 — 19,049 —

Employee Retirement Plan

Employee Retirement Plan	9 Months Ended
	Sep. 30, 2016
Compensation And Retirement Disclosure [Abstract]
Employee Retirement Plan	11. Employee Retirement Plan The Company maintains a retirement plan (the “401(k) Plan”) authorized by Section 401(k) of the Internal Revenue Code. In accordance with the 401(k) Plan, all employees are eligible to participate in the 401(k) Plan as of the first day of the month following commencement of employment. Each employee can contribute a percentage of compensation up to a maximum of the statutory limits per year. Company contributions are discretionary, and no contributions were made during either of the three and nine months ended September 30, 2016 and September 30, 2015.

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2016
Income Tax Disclosure [Abstract]
Income Taxes	12. Income Taxes The Company estimates an annual effective tax rate of 0% for the year ending December 31, 2016, as the Company incurred losses for the three and nine months ended September 30, 2016 and is forecasting additional losses through the end of 2016, resulting in an estimated net loss for both financial statement and tax purposes for the year ending December 31, 2016. Due to the Company’s history of losses since inception, there is not enough evidence at this time to support that the Company will generate future income of a sufficient amount and nature to utilize the benefits of its net deferred tax assets. Accordingly, the deferred tax assets have been reduced by a valuation allowance, since it has been determined that it is more likely than not that all of the deferred tax assets will not be realized. Therefore, no federal or state income taxes are expected and none have been recorded as of September 30, 2016. Income taxes have been accounted for using the liability method. Utilization of the Company’s Net Operating Loss carryforward (“NOL”) may be subject to a substantial annual limitation due to ownership change limitations that have occurred or that could occur in the future, as required by Section 382 and Section 383 of the Internal Revenue Code of 1986, as amended (the "Code"), as well as similar state and foreign provisions. These ownership changes may limit the amount of NOLs that can be utilized annually to offset future taxable income and tax. In general, an "ownership change" as defined by Section 382 of the Code results from a transaction or series of transactions over a three-year period resulting in an ownership change of more than 50 percentage points of the outstanding stock of a company by certain shareholders. The Company has not completed a study to assess whether an ownership change has occurred or whether there have been multiple ownership changes since its formation. The Company has not recorded NOLs that, as a result of these restrictions, will expire unused.

Recent Accounting Pronouncement

Recent Accounting Pronouncements	9 Months Ended
	Sep. 30, 2016
Accounting Changes And Error Corrections [Abstract]
Recent Accounting Pronouncements	13. Recent Accounting Pronouncements In May 2014, the FASB issued Accounting Standards Update (“ASU”) No. 2014-09, Revenue from Contracts with Customers In August 2014, the FASB issued ASU No. 2014-15, Presentation of Financial Statements—Going Concern (Subtopic 205-40): Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern, In November 2015, the FASB issued ASU No. 2015-17, Income Taxes (Topic 740): Balance Sheet Classification of Deferred Taxes In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) In March 2016, the FASB issued ASU No. 2016-09, Improvements to Employee Share-Based Payment Accounting In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments

Summary of Significant Accoun20

Summary of Significant Accounting Policies and Basis of Presentation (Policies)	9 Months Ended
	Sep. 30, 2016
Accounting Changes And Error Corrections [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited condensed financial statements of the Company have been prepared in accordance with accounting principles generally accepted in the United States (“GAAP”) for interim financial reporting and pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”). Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements. In the opinion of management, all adjustments (including those which are normal and recurring) considered necessary for a fair presentation of the interim financial information have been included. When preparing financial statements in conformity with GAAP, the Company must make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues, expenses and related disclosures at the date of the financial statements. Actual results could differ from those estimates. Additionally, operating results for the three and nine months ended September 30, 2016 are not necessarily indicative of the results that may be expected for any other interim period or for the fiscal year ending December 31, 2016. The condensed interim financial statements should be read in conjunction with the audited financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2015 filed with the SEC.
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 in the financial statements and accompanying notes. Estimates are used in the following areas, among others: stock-based compensation expense, accrued expenses and income taxes. Actual results could materially differ from those estimates.
Cash and Cash Equivalents	Cash and Cash Equivalents Cash and cash equivalents consist of all cash on hand, deposits and funds invested in available for sale securities with original maturities of three months or less at the time of purchase. At September 30, 2016, the Company’s cash was primarily in money market funds. The Company may maintain balances with its banks in excess of federally insured limits.
Available for Sale Securities	Available for Sale Securities Management determines the appropriate classification of securities at the time of purchase and reevaluates such designation as of each balance sheet date. Currently, the Company classifies all securities as available for sale which are included in current and non-current assets. The Company carries available for sale securities at fair value based on current market value. The Company conducts periodic reviews to identify and evaluate each investment that has an unrealized loss, in accordance with the meaning of other-than-temporary impairment and its application to certain investments. When assessing whether a decline in the fair value of a security is other-than-temporary, the Company considers the fair market value of the security, the duration of the security’s decline, and prospects for the underlying business. Based on these considerations, the Company did not identify any other-than-temporary impairments at September 30, 2016. Unrealized losses on available for sale securities that are determined to be temporary, and not related to credit loss, are recorded, net of tax, in accumulated other comprehensive loss, a component of stockholders’ equity. The amortized cost of debt securities in this category reflects amortization of premiums and accretion of discounts to maturity computed under the effective interest method. The Company includes this amortization in the caption “Interest income, net” within the Condensed Statements of Operations and Comprehensive Loss. The Company also includes in interest income, net, realized gains and losses and declines in value determined to be other than temporary. The Company bases the cost of securities sold upon the specific identification method, and includes interest and dividends on securities in interest income.
Concentration of Credit Risk	Concentration of Credit Risk Financial instruments, which potentially subject the Company to significant concentration of credit risk, consist primarily of cash, cash equivalents, corporate debt securities, commercial paper and U.S. Treasuries. The Company maintains deposits in federally insured institutions in excess of federally insured limits. The Company has not experienced any losses in such accounts and management believes that the Company is not exposed to significant credit risk due to the financial position of the depository institutions in which those deposits are held. Substantially all of the Company’s available for sale securities are with companies that management believes to be of high-credit quality with short-term credit ratings of at least A-1/P-1 or better by Standard and Poor’s and Moody’s Investor Service at the time of purchase. The Company has no financial instruments with off-balance sheet risk of loss.
Distribution and Supply Agreement	Distribution and Supply Agreement On October 23, 2013, the Company entered into a distribution and supply agreement with Ildong Pharmaceutical Co., Ltd. (“Ildong”) for lasmiditan in the Republic of Korea, Taiwan, Singapore, Malaysia, Indonesia, Philippines, Thailand, Myanmar and Vietnam, which is referred to as the territory. During the term of the agreement, the Company must use commercially reasonable efforts to supply Ildong with the amount of lasmiditan that it requires. Under the terms of the agreement, the Company received an upfront payment of $1.5 million as consideration for the Company granting Ildong exclusive rights to develop and commercialize lasmiditan in the territory as well as the Company’s agreement to provide lasmiditan to Ildong in the future for a reduced purchase price. This $1.5 million upfront payment is reflected in deferred revenue as of September 30, 2016 and December 31, 2015, and will be recognized as revenue in the event the Company sells lasmiditan to Ildong for commercial sale. In the event the Company has no further obligations under this agreement prior to the date regulatory approval is obtained, if at all, the Company will recognize this upfront payment as revenue at that time since lasmiditan would not have been sold and delivered to Ildong for commercial sale. The Company also has the potential to receive aggregate potential future milestone payments from Ildong of up to $3.5 million, including (i) $1 million upon the submission of a new drug application to the FDA or a submission of an equivalent regulatory filing to the European Medicines Agency in the European Union; (ii) $1.5 million upon obtaining approval of lasmiditan by the FDA or the European Medicines Agency; and (iii) $1 million upon obtaining approval of lasmiditan in the Republic of Korea. The Company will supply Ildong with lasmiditan for use in clinical trials in the territory, for which Ildong will pay to the Company an amount equal to the Company’s fully burdened manufacturing cost (or the Company’s fully burdened cost of goods if lasmiditan is obtained from a third-party supplier for such trials), plus 5% per tablet of lasmiditan. If approved in the territory, the Company will also supply Ildong with lasmiditan for sale in the territory, for which Ildong will pay to the Company a purchase price per unit calculated as a percentage (ranging from 31.5% to 36.5%) of the net sales of lasmiditan in the territory. Ildong will be responsible for the costs and activities related to development and regulatory approvals in the territory as part of the global development plan under the agreement. The agreement terminates upon the later of the expiration of the Company’s patents in the territory or 15 years after the first commercialization of lasmiditan, and is subject to certain renewal rights. The agreement may be terminated by mutual agreement or by either party in the case of uncured material breach or bankruptcy. The Company has the right to terminate if Ildong challenges any of the Company’s patents or fails to adequately commercialize lasmiditan in the territory.
Stock-Based Compensation	Stock-Based Compensation The Company recognizes compensation cost relating to stock-based payment transactions in operating results using a fair-value measurement method, in accordance with Accounting Standards Codification (“ASC”) Topic 718, Compensation-Stock Compensation Grants to non-employees are accounted for in accordance with ASC Topic 505-50, Equity-Based Payments to Non-Employees Compensation cost associated with restricted stock unit (“RSU”) grants is based on the fair value of the RSUs granted (which is the closing price of the Company’s common stock on the date of grant multiplied by the number of RSUs in the grant), adjusted for the expected forfeiture rate.
Income Taxes	Income Taxes The Company accounts for income taxes under the liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements. Under this method, deferred tax assets and liabilities are determined on the basis of the differences between the financial statements and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in income in the period that includes the enactment date. The Company recognizes net deferred tax assets to the extent that the Company believes these assets are more likely than not to be realized. In making such a determination, management considers all available positive and negative evidence, including future reversals of existing temporary differences, projected future taxable income, tax-planning strategies, and result of recent operations. If management determines that the Company would be able to realize its deferred tax assets in the future, in excess of its net recorded amount, management would make an adjustment to the deferred tax asset valuation allowance, which would reduce the provision for income taxes. The Company records uncertain tax positions on the basis of a two-step process whereby (1) management determines whether it is more likely than not that the tax positions will be sustained on the basis of the technical merits of the position and (2) for those tax positions that meet the more likely than not recognition threshold, management recognizes the largest amount of tax benefit that is more than 50% likely to be realized upon ultimate settlement with the related tax authority. The Company recognizes interest and penalties related to unrecognized tax benefits within income tax expense. Any accrued interest and penalties are included within the related tax liability. In November 2015, the FASB issued ASU No. 2015-17, Income Taxes (Topic 740): Balance Sheet Classification of Deferred Taxes
Accrued Research and Development Expenses	Accrued Research and Development Expenses As part of the process of preparing its financial statements, the Company is required to estimate its accrued research and development expenses. This process involves reviewing open contracts and purchase orders, communicating with the Company’s personnel to identify services that have been performed on the Company’s behalf and estimating the level of service performed and the associated cost incurred for the service when the Company has not yet been invoiced or otherwise notified of the actual cost. The majority of the Company’s service providers invoice the Company monthly in arrears for services performed. The Company makes estimates of its accrued expenses as of each balance sheet date in its financial statements based on facts and circumstances known to it at that time. The Company confirms the accuracy of its estimates with the service providers and makes adjustments if necessary. Examples of estimated accrued research and development expenses include expenses for: • Contract Research Organizations (“CRO”) in connection with clinical studies; • investigative sites in connection with clinical studies; • vendors in connection with preclinical development activities; and • vendors related to product manufacturing, development and distribution of clinical materials. The Company bases its accrued expenses related to clinical studies on its estimates of the services received and efforts expended pursuant to contracts with its CRO that conducts and manages clinical studies on the Company’s behalf. The financial terms of these agreements are subject to negotiation, vary from contract to contract and may result in uneven payment flows. The scope of services under these contracts can be modified and some of the agreements may be cancelled by either party upon written notice. There may be instances in which payments made to the Company’s vendors will exceed the level of services provided and result in a prepayment of the clinical expense. Payments under some of these contracts with CROs depend on factors such as the successful enrollment of subjects and the completion of clinical study milestones. In accruing service fees, the Company estimates the time period over which services will be performed and the level of effort to be expended in each period. If the actual timing of the performance of services or the level of effort varies from the Company’s estimate, the Company adjusts the accrual or prepaid expense accordingly. Although the Company does not expect its estimates to be materially different from amounts actually incurred, if its estimates of the status and timing of services performed differ from the actual status and timing of services performed, the Company may report amounts that are too high or too low in any particular period. To date, there have been no material differences between its estimates and the amount actually incurred.
Net Loss Per Common Share	Net Loss Per Common Share Basic net loss per common share is calculated by dividing net loss attributable to common stockholders by the weighted-average number of common shares outstanding during the period, without consideration for common stock equivalents or unvested restricted stock units. Diluted net loss per share is computed by dividing the net loss attributable to common stockholders by the weighted-average number of common share equivalents outstanding for the period determined using the treasury-stock method. For purposes of this calculation, convertible preferred stock, stock options, RSUs and shares to be purchased under the ESPP are considered to be common stock equivalents and are only included in the calculation of diluted net loss per share when their effect is dilutive.
Subsequent Events	Subsequent Events The Company has evaluated all subsequent events through the date of this filing.
Revenue from Contracts with Customers	In May 2014, the FASB issued Accounting Standards Update (“ASU”) No. 2014-09, Revenue from Contracts with Customers
Presentation of Financial Statements-Going Concern	In August 2014, the FASB issued ASU No. 2014-15, Presentation of Financial Statements—Going Concern (Subtopic 205-40): Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern,
Leases	In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842)
Improvements to Employee Share-Based Payment Accounting	In March 2016, the FASB issued ASU No. 2016-09, Improvements to Employee Share-Based Payment Accounting
Classification of Certain Cash Receipts and Cash Payments	In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments

Available for Sale Securities (

Available for Sale Securities (Tables)	9 Months Ended
	Sep. 30, 2016
Investments Debt And Equity Securities [Abstract]
Available for Sale Securities	The following table summarizes the available for sale securities held by the Company at September 30, 2016 and December 31, 2015: Gross Unrealized Description Amortized Cost Gains / (Losses) Fair Value (in thousands) September 30, 2016 Available for sale securities: Corporate debt securities $ 3,810 $ (1 ) $ 3,809 Commercial paper 3,798 — 3,798 U.S. Government debt securities 9,026 8 9,034 Total available for sale securities $ 16,634 $ 7 $ 16,641 December 31, 2015 Available for sale securities: Corporate debt securities $ 36,573 (43 ) 36,530 Total available for sale securities $ 36,573 $ (43 ) $ 36,530
Schedule of Estimated Fair Value of Company's Available For Sale Securities	The estimated fair value of the Company’s available for sale securities at September 30, 2016 by contractual maturity, was as follows: September 30, 2016 (in thousands) Due in one year or less $ 16,641 Due after one year — Total available for securities $ 16,641

Fair Value of Financial Instr22

Fair Value of Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2016
Fair Value Disclosures [Abstract]
Schedule of Financial Instruments Measured at Fair Value Based on Three Fair Value Hierarchy Tiers	Financial instruments measured at fair value are classified below based on the three fair value hierarchy tiers described above: Significant Quoted prices other Significant in active observable unobservable markets inputs inputs Total (Level 1) (Level 2) (Level 3) (in thousands) September 30, 2016 Assets Cash and money market $ 83,540 $ 83,540 $ — $ — Commercial paper 3,798 — 3,798 — Corporate debt securities 3,809 — 3,809 — U.S. Government debt securities 9,034 — 9,034 — Total $ 100,181 $ 83,540 $ 16,641 $ — December 31, 2015 Assets Cash and money market $ 27,978 $ 27,978 $ — $ — Corporate debt securities 36,530 — 36,530 — Total $ 64,508 $ 27,978 $ 36,530 $ —

Accrued liabilities (Tables)

Accrued liabilities (Tables)	9 Months Ended
	Sep. 30, 2016
Payables And Accruals [Abstract]
Schedule of Accrued Expenses	Accrued expenses consist of the following: September 30, December 31, 2016 2015 (in thousands) Payroll and employee-related costs $ 579 $ 669 Clinical trial costs 3,028 1,933 Research and development costs 650 707 Professional fees 432 266 Excise tax payable 63 126 Other 30 79 $ 4,782 $ 3,780

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2016
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Stock Option Activity	The following summarizes the stock option activity during the period: Weighted- Weighted- average Aggregate average remaining intrinsic price contractual value Shares per share term (years) (in thousands) Outstanding at December 31, 2015 1,215,828 $ 9.34 9.4 $ 462 Granted 371,577 7.26 10 Exercised (158,404 ) 9.03 1,935 Cancelled / Expired (44,613 ) 10.00 — Outstanding at September 30, 2016 1,384,388 $ 8.79 8.8 $ 40,644 Options exercisable at September 30, 2016 460,396 $ 9.61 8.6 $ 13,142 Options vested and expected to vest as of September 30, 2016 1,227,115 $ 8.86 8.8 $ 35,944
Summary of RSU Activity	The following summarizes RSU activity for the nine months ended September 30, 2016: Weighted- Aggregate average grant intrinsic date fair value value Shares per share (in thousands) Unvested balance at December 31, 2015 180,254 $ 10.00 $ 1,509 Granted 158,000 6.75 1,067 Vested (83,128 ) 9.10 Forfeited — — Outstanding at September 30, 2016 255,126 $ 8.28 $ 9,733 Vested and unsettled as of September 30, 2016 23,042 $ 6.75 $ 879 Vested and expected to vest as of September 30, 2016 247,030 $ 8.27 $ 9,424
Schedule of Compensation Cost Related to Share-based Awards	The Company recognized the following compensation cost related to share-based awards in the three and nine months ended Three months ended Nine months ended September 30, September 30, 2016 2015 2016 2015 (in thousands) (in thousands) Research and development $ 206 $ 177 $ 648 $ 293 General and administrative 561 1,795 2,021 2,833 Total $ 767 $ 1,972 $ 2,669 $ 3,126
Schedule of Compensation Expense by Type of Award	Compensation expense by type of award in the three and nine months ended September 30, 2016 was as follows: Three months ended Nine months ended September 30, September 30, 2016 2015 2016 2015 (in thousands) (in thousands) Stock options $ 569 $ 1,075 $ 1,934 $ 1,671 Restricted stock units 179 897 671 1,455 Employee Stock Purchase Plan 19 — 64 — Total $ 767 $ 1,972 $ 2,669 $ 3,126

Net Loss Per Common Share (Tabl

Net Loss Per Common Share (Tables)	9 Months Ended
	Sep. 30, 2016
Earnings Per Share [Abstract]
Computation of Basic And Diluted Net Loss per Share	The following table sets forth the computation of basic and diluted net loss per share applicable to common stockholders (in thousands, except share and per share data): Three months ended Nine months ended September 30, September 30, 2016 2015 2016 2015 Numerator: Net loss $ (12,657 ) $ (8,950 ) $ (41,994 ) $ (19,510 ) Gain on extinguishment of convertible stock — — — 4,798 Accretion of redeemable convertible preferred stock — — — (12,553 ) Net loss attributable to common stockholders $ (12,657 ) $ (8,950 ) $ (41,994 ) $ (27,265 ) Denominator: Weighted average common shares outstanding - Basic and Diluted 16,057,462 15,153,135 15,543,386 8,336,147 Net loss per share attributable to common stockholders - Basic and Diluted $ (0.79 ) $ (0.59 ) $ (2.70 ) $ (3.27 )
Schedule of Antidilutive Securities Excluded from Calculation of Diluted Weighted-Average Shares	The common stock equivalents in the table below were excluded from the calculation of diluted weighted-average shares outstanding due to their anti-dilutive effect: Three months ended Nine months ended September 30, September 30, 2016 2015 2016 2015 Convertible preferred stock — — — 3,971,137 Outstanding stock options 1,509,614 1,183,322 1,441,631 655,026 Restricted stock units 283,809 360,508 278,464 196,761 Employee Stock Purchase Plan shares 15,961 — 19,049 —

Nature of Operations - Addition

Nature of Operations - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	Sep. 14, 2016	May 11, 2015	May 05, 2015	Sep. 30, 2016	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015	Dec. 31, 2014
Basis of Presentation [Line Items]
Net proceeds from offering of common stock							$ 69,920	$ 49,816
Net loss					$ (12,657)	$ (8,950)	(41,994)	$ (27,265)	$ (38,500)	$ (3,000)
Accumulated deficit				$ (129,089)	$ (129,089)		$ (129,089)		$ (87,095)
Stockholders' equity, reverse stock split							one-for-40.7
Additional shares of common stock outstanding			9,489,659
Follow-on Public Offering [Member]
Basis of Presentation [Line Items]
Net proceeds from offering of common stock	$ 69,900			$ 69,900
Number of shares of common stock sold	3,737,500
Sale of stock price per share at public offering	$ 20
Expenses paid by the company	$ 300
Underwriting discounts and commissions	$ 4,600
IPO [Member]
Basis of Presentation [Line Items]
Number of shares of common stock sold		5,500,000
Sale of stock price per share at public offering		$ 10
Net proceeds from the IPO		$ 49,800
Expenses paid by the company		$ 1,300

Summary of Significant Accoun27

Summary of Significant Accounting Policies and Basis of Presentation - Additional Information (Detail) - USD ($) $ in Thousands	Oct. 23, 2013	Sep. 30, 2016	Dec. 31, 2015
Accounting Policies [Line Items]
Deferred revenue on upfront payment		$ 1,500	$ 1,500
Ildong [Member]
Accounting Policies [Line Items]
Upfront payment received	$ 1,500
Deferred revenue on upfront payment		$ 1,500	$ 1,500
Aggregate potential milestone payments receivable	$ 3,500
Percentage of payment received upon manufacturing cost per tablet	5.00%
Agreement expiration period		15 years
Ildong [Member] | Minimum [Member]
Accounting Policies [Line Items]
Percentage of purchase price per unit on net sales	31.50%
Ildong [Member] | Maximum [Member]
Accounting Policies [Line Items]
Percentage of purchase price per unit on net sales	36.50%
Ildong [Member] | US Food and Drug Administration or European Medicines Agency [Member]
Accounting Policies [Line Items]
Potential milestone payment receivable upon submission of drug	$ 1,000
Potential milestone payment receivable upon approval of drug	1,500
Ildong [Member] | Republic of Korea [Member]
Accounting Policies [Line Items]
Potential milestone payment receivable upon approval of drug	$ 1,000

Available For Sale Securities -

Available For Sale Securities - Summary of Available for Sale Securities (Detail) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	$ 16,634	$ 36,573
Gross Unrealized Gains / (Losses)	7	(43)
Fair Value	16,641	36,530
Corporate Debt Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	3,810	36,573
Gross Unrealized Gains / (Losses)	(1)	(43)
Fair Value	3,809	$ 36,530
Commercial Paper [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	3,798
Fair Value	3,798
U.S. Government Debt Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	9,026
Gross Unrealized Gains / (Losses)	8
Fair Value	$ 9,034

Available For Sale Securities29

Available For Sale Securities - Schedule of Estimated Fair Value of Company's Available For Sale Securities (Detail) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Investments Debt And Equity Securities [Abstract]
Due in one year or less	$ 16,641	$ 36,530
Total available for securities	$ 16,641	$ 36,530

Fair Value of Financial Instr30

Fair Value of Financial Instruments - Additional Information (Detail) - USD ($)	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, Transfer of assets and liabilities between level one two and three	$ 0	$ 0	$ 0
Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of liabilities	$ 0	$ 0	$ 0

Fair Value of Financial Instr31

Fair Value of Financial Instruments - Schedule of Financial Instruments Measured at Fair Value Based on Three Fair Value Hierarchy Tiers (Detail) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Assets
Total fair value of financial instruments	$ 100,181	$ 64,508
Cash and Money Market [Member]
Assets
Total fair value of financial instruments	83,540	27,978
Commercial Paper [Member]
Assets
Total fair value of financial instruments	3,798
Corporate Debt Securities [Member]
Assets
Total fair value of financial instruments	3,809	36,530
U.S. Government Debt Securities [Member]
Assets
Total fair value of financial instruments	9,034
Quoted Prices in Active Markets (Level 1) [Member]
Assets
Total fair value of financial instruments	83,540	27,978
Quoted Prices in Active Markets (Level 1) [Member] | Cash and Money Market [Member]
Assets
Total fair value of financial instruments	83,540	27,978
Significant Other Observable Inputs (Level 2) [Member]
Assets
Total fair value of financial instruments	16,641	36,530
Significant Other Observable Inputs (Level 2) [Member] | Commercial Paper [Member]
Assets
Total fair value of financial instruments	3,798
Significant Other Observable Inputs (Level 2) [Member] | Corporate Debt Securities [Member]
Assets
Total fair value of financial instruments	3,809	36,530
Significant Other Observable Inputs (Level 2) [Member] | U.S. Government Debt Securities [Member]
Assets
Total fair value of financial instruments	9,034
Significant Unobservable Inputs (Level 3) [Member]
Assets
Total fair value of financial instruments	0	0
Significant Unobservable Inputs (Level 3) [Member] | Cash and Money Market [Member]
Assets
Total fair value of financial instruments	0	0
Significant Unobservable Inputs (Level 3) [Member] | Commercial Paper [Member]
Assets
Total fair value of financial instruments	0
Significant Unobservable Inputs (Level 3) [Member] | Corporate Debt Securities [Member]
Assets
Total fair value of financial instruments	0	$ 0
Significant Unobservable Inputs (Level 3) [Member] | U.S. Government Debt Securities [Member]
Assets
Total fair value of financial instruments	$ 0

Accrued Liabilities - Schedule

Accrued Liabilities - Schedule of Accrued Expenses (Detail) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Accrued Liabilities Current [Abstract]
Payroll and employee-related costs	$ 579	$ 669
Clinical trial costs	3,028	1,933
Research and development costs	650	707
Professional fees	432	266
Excise tax payable	63	126
Other	30	79
Total accrued expenses	$ 4,782	$ 3,780

Notes Payable - Additional Info

Notes Payable - Additional Information (Detail) - USD ($)	1 Months Ended
	Dec. 31, 2014	Dec. 15, 2014
Line of Credit Facility [Line Items]
Convertible notes payable, initial closing amount		$ 200,000
Maximum [Member] | Bridge Loan Financing [Member]
Line of Credit Facility [Line Items]
Convertible Note Purchase Agreement with certain investors to provide Bridge Loans	$ 1,000,000

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) - USD ($)	Sep. 15, 2015	Feb. 10, 2005	Sep. 30, 2016	Dec. 31, 2015
American Twine Limited Partnership [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Estimated rent expense	$ 258,000
Term of operating lease agreements	2 years
Rent expense			$ 103,000	$ 83,000
Anticipated rent payment for 2016			136,000
Anticipated rent payment for 2017			92,000
Lilly [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
License agreement date		Dec. 16, 2005
Upfront license fee			$ 1,000,000
Lilly [Member] | Minimum [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Royalty percentage obligated for payment			8.00%
Lilly [Member] | First Indication [Member] | Maximum [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
License agreement fee			$ 32,000,000
Royalty percentage obligated for payment			11.00%
Lilly [Member] | Subsequent Indication [Member] | Maximum [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
License agreement fee			$ 3,000,000

Issuance of Preferred Stock - A

Issuance of Preferred Stock - Additional Information (Detail) - USD ($)	Jan. 12, 2015	Sep. 30, 2016	Sep. 30, 2015
Temporary Equity [Line Items]
Conversion of convertible notes payable to preferred stock			$ 200,000
Convertible preferred stock redeemable period		5 years
Series C Redeemable Convertible Preferred Stock [Member]
Temporary Equity [Line Items]
Redeemable convertible preferred stock, shares issued	4,344,567
Redeemable convertible preferred stock conversion in cash	$ 36,900,000
Conversion of convertible notes payable to preferred stock	$ 200,000
Series A Redeemable Convertible Preferred Stock [Member]
Temporary Equity [Line Items]
Redeemable convertible preferred stock, shares issued	1,426,353
Series B Redeemable Convertible Preferred Stock [Member]
Temporary Equity [Line Items]
Redeemable convertible preferred stock, shares issued	2,647,102
Series A and Series B Convertible Preferred Stock [Member]
Temporary Equity [Line Items]
Fair value on convertible preferred stock, inducement	$ 4,798,194

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Detail) - USD ($)	Jan. 01, 2016	May 05, 2015	Mar. 31, 2016	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2014	Dec. 31, 2015	Apr. 16, 2015
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares granted during period						371,577
Employee payroll deductions included in additional paid in capital				$ 579,000		$ 579,000			$ 669,000
Compensation expense				$ 767,000	$ 1,972,000	$ 2,669,000	$ 3,126,000
Employee Stock Purchase Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for issuance										300,000
Percentage of shares outstanding								1.00%
Increase in number of shares available for issuance								150,000
Future issuance of employee stock purchase plan				428,481		428,481
Employee payroll deductions included in additional paid in capital				$ 148,000		$ 148,000
Compensation expense				$ 19,000		$ 64,000
Equity Award Plans [Member] | 2006 Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares granted during period						0
Equity Award Plans [Member] | 2015 Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares granted during period						527,812
Common stock reserved for issuance										1,819,100
Reserved share, percentage of outstanding shares										6.00%
Shares authorized and reserved for issuance										1,200,000
Additional number of shares reserved for issuance	687,312
Stock Option Awards [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected dividend rate						0.00%
Contractual term, options						10 years
Contractual term, vesting						4 years
Closing price of common stock				$ 38.15		$ 38.15
Unrecognized stock-based compensation expense relating to unvested employee stock options				$ 3,900,000	5,200,000	$ 3,900,000	5,200,000
Unrecognized stock-based compensation expense, weighted average period						2 years 7 months 6 days
Weighted average fair value of options granted				$ 9.62		$ 7.26
Compensation expense				$ 569,000	1,075,000	$ 1,934,000	1,671,000
Stock Option Awards [Member] | Minimum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Risk-free interest rate						0.50%
Expected average option life						3 months 18 days
Expected volatility						75.90%
Expected forfeiture rate						12.40%
Stock Option Awards [Member] | Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Risk-free interest rate						2.10%
Expected average option life						10 years
Expected volatility						98.70%
Expected forfeiture rate						14.80%
Restricted Stock Units [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Contractual term, vesting			48 months
Unrecognized stock-based compensation expense, weighted average period						2 years 10 months 24 days
Restricted shares issued		360,508	158,000
Restricted stock granted, weighted average fair value		$ 10				$ 6.75
Restricted stock requisite service period		4 years	4 years
Description of vesting of restricted stock units						whereby the awards vest in a series of 48 successive equal monthly installments with the first monthly installment vesting on the grant date and the future installments vesting on the first day of each calendar month thereafter.
Unrecognized compensation cost				1,800,000		$ 1,800,000
Compensation expense				$ 179,000	$ 897,000	$ 671,000	$ 1,455,000
Restricted Stock Units [Member] | After Six Month Of Grant [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Restricted stock award vested percentage		50.00%
Restricted Stock Units [Member] | After One Year Of Grant [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Contractual term, vesting		1 year
Restricted stock award vested percentage		12.50%
Restricted Stock Units [Member] | After Thirty Six Months Of Grant [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Contractual term, vesting		36 months

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Stock Option Activity (Detail) - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2016	Dec. 31, 2015
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Shares, Outstanding beginning balance	1,215,828
Shares, Granted	371,577
Shares, Exercised	(158,404)
Shares, Cancelled / Expired	(44,613)
Shares, Outstanding ending balance	1,384,388	1,215,828
Shares, Options exercisable at September 30, 2016	460,396
Shares, Options vested and expected to vest as of September 30, 2016	1,227,115
Weighted- average price per share, Outstanding beginning balance	$ 9.34
Weighted- average price per share, Granted	7.26
Weighted- average price per share, Exercised	9.03
Weighted- average price per share, Cancelled / Expired	10
Weighted- average price per share, Outstanding ending balance	8.79	$ 9.34
Weighted- average price per share, Options exercisable at September 30, 2016	9.61
Weighted- average price per share, Options vested and expected to vest as of September 30, 2016	$ 8.86
Weighted- average remaining contractual term	8 years 9 months 18 days	9 years 4 months 24 days
Weighted- average remaining contractual term, Options exercisable at September 30, 2016	8 years 7 months 6 days
Weighted- average remaining contractual term, Options vested and expected to vest September 30, 2016	8 years 9 months 18 days
Aggregate intrinsic value, Outstanding	$ 462
Aggregate intrinsic value, Granted	10
Aggregate intrinsic value, Exercised	1,935
Aggregate intrinsic value, Outstanding	40,644	$ 462
Aggregate intrinsic value, Options exercisable at September 30, 2016	13,142
Aggregate intrinsic value, Options vested and expected to vest as of September 30, 2016	$ 35,944

Stock-Based Compensation - Su38

Stock-Based Compensation - Summary of RSU Activity (Detail) - Restricted Stock Units [Member] - USD ($) $ / shares in Units, $ in Thousands	May 05, 2015	Sep. 30, 2016
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unvested Shares, beginning balance		180,254
Shares, Granted		158,000
Shares, Vested		(83,128)
Unvested Shares, ending balance		255,126
Shares, Vested and unsettled		23,042
Shares, Vested and expected to vest		247,030
Weighted- average grant date fair value per share, Unvested Shares beginning balance		$ 10
Weighted- average grant date fair value per share, Granted	$ 10	6.75
Weighted- average grant date fair value per share, Vested		9.10
Weighted- average grant date fair value per share, Unvested Shares ending balance		8.28
Weighted- average grant date fair value per share, Vested and unsettled		6.75
Weighted- average grant date fair value per share, Vested and expected to vest		$ 8.27
Aggregate intrinsic value, Unvested beginning balance		$ 1,509
Aggregate intrinsic value, Granted		1,067
Aggregate intrinsic value, Unvested ending balance		9,733
Aggregate intrinsic value, Vested and unsettled		879
Aggregate intrinsic value, Vested and expected to vest		$ 9,424

Stock-Based Compensation - Sche

Stock-Based Compensation - Schedule of Compensation Cost Related to Share-based Awards (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation expense	$ 767	$ 1,972	$ 2,669	$ 3,126
Research and Development [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation expense	206	177	648	293
General and Administrative [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation expense	$ 561	$ 1,795	$ 2,021	$ 2,833

Stock-Based Compensation - Sc40

Stock-Based Compensation - Schedule of Compensation Expense by Type of Award (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation expense	$ 767,000	$ 1,972,000	$ 2,669,000	$ 3,126,000
Stock Option Awards [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation expense	569,000	1,075,000	1,934,000	1,671,000
Restricted Stock Units [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation expense	179,000	$ 897,000	671,000	$ 1,455,000
Employee Stock Purchase Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation expense	$ 19,000		$ 64,000

Net Loss Per Common Share - Com

Net Loss Per Common Share - Computation of Basic And Diluted Net Loss per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015	Dec. 31, 2014
Numerator:
Net loss	$ (12,657)	$ (8,950)	$ (41,994)	$ (19,510)
Gain on extinguishment of convertible stock				4,798
Accretion of redeemable convertible preferred stock				(12,553)
Net loss attributable to common stockholders	$ (12,657)	$ (8,950)	$ (41,994)	$ (27,265)	$ (38,500)	$ (3,000)
Denominator:
Weighted average common shares outstanding -Basic and Diluted	16,057,462	15,153,135	15,543,386	8,336,147
Net loss per share attributable to common stockholders - Basic and Diluted	$ (0.79)	$ (0.59)	$ (2.70)	$ (3.27)

Net Loss Per Common Share - Sch

Net Loss Per Common Share - Schedule of Antidilutive Securities Excluded from Calculation of Diluted Weighted-Average Shares (Detail) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Convertible Preferred Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Common stock equivalents excluded from calculation of diluted weighted-average shares outstanding				3,971,137
Outstanding Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Common stock equivalents excluded from calculation of diluted weighted-average shares outstanding	1,509,614	1,183,322	1,441,631	655,026
Restricted Stock Units [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Common stock equivalents excluded from calculation of diluted weighted-average shares outstanding	283,809	360,508	278,464	196,761
Employee Stock Purchase Plan Shares [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Common stock equivalents excluded from calculation of diluted weighted-average shares outstanding	15,961		19,049

Employee Retirement Plan - Addi

Employee Retirement Plan - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Compensation And Retirement Disclosure [Abstract]
Contribution of retirement plan, employee discretionary contribution amount	$ 0	$ 0	$ 0	$ 0

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($)	9 Months Ended	12 Months Ended
	Sep. 30, 2016	Dec. 31, 2016
Schedule Of Income Tax [Line Items]
Federal income taxes	$ 0
State income taxes	$ 0
Minimum percentage of ownership change that would have impact in Net operating loss carryforward	50.00%
Effect of ownership changes in net operating loss carryforward series of transactions period	3 years
Scenario, Forecast [Member]
Schedule Of Income Tax [Line Items]
Effective tax rate		0.00%