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Document and Entity Information - shares	9 Months Ended
Document and Entity Information - shares	Sep. 30, 2017	Nov. 08, 2017
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2017
Document Fiscal Year Focus	2017
Document Fiscal Period Focus	Q3
Trading Symbol	ITCI
Entity Registrant Name	Intra-Cellular Therapies, Inc.
Entity Central Index Key	0001567514
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		54,577,626

Condensed Consolidated Balance Sheets - USD ($)	Sep. 30, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 52,340,519	$ 48,642,225
Investment securities, available-for-sale	275,781,285	335,458,459
Accounts receivable	6,309	94,339
Prepaid expenses and other current assets	5,307,357	4,005,093
Total current assets	333,435,470	388,200,116
Property and equipment, net	679,606	627,614
Other assets	75,765	75,765
Total assets	334,190,841	388,903,495
Current liabilities:
Accounts payable	4,407,655	3,754,647
Accrued and other current liabilities	4,151,120	5,329,293
Accrued employee benefits	3,316,378	1,448,394
Total current liabilities	11,875,153	10,532,334
Long-term liabilities	2,875,612	2,868,622
Total liabilities	14,750,765	13,400,956
Stockholders' equity:
Common stock, $.0001 par value: 100,000,000 shares authorized; 43,427,344 and 43,292,906 shares issued and outstanding at September 30, 2017 and December 31, 2016, respectively	4,342	4,329
Additional paid-in capital	696,695,317	685,290,815
Accumulated deficit	(377,040,068)	(309,475,366)
Accumulated comprehensive loss	(219,515)	(317,239)
Total stockholders' equity	319,440,076	375,502,539
Total liabilities and stockholders' equity	$ 334,190,841	$ 388,903,495

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	43,427,344	43,292,906
Common stock, shares outstanding	43,427,344	43,292,906

Condensed Consolidated Statements of Operations (Unaudited) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Income Statement [Abstract]
Revenues	$ 30,754	$ 4,362	$ 240,782	$ 232,807
Costs and expenses:
Research and development	18,472,372	23,918,232	52,489,968	72,652,520
General and administrative	5,317,577	6,270,528	17,882,679	17,806,565
Total costs and expenses	23,789,949	30,188,760	70,372,647	90,459,085
Loss from operations	(23,759,195)	(30,184,398)	(70,131,865)	(90,226,278)
Interest expense		(12,260)		(12,260)
Interest income	884,763	763,949	2,564,747	2,129,927
Loss before provision for income taxes	(22,874,432)	(29,432,709)	(67,567,118)	(88,108,611)
Income tax benefit (expense)	4,016	(832,618)	2,416	(832,618)
Net loss	$ (22,870,416)	$ (30,265,327)	$ (67,564,702)	$ (88,941,229)
Net loss per common share:
Basic & Diluted	$ (0.53)	$ (0.70)	$ (1.56)	$ (2.06)
Weighted average number of common shares:
Basic & Diluted	43,424,387	43,253,429	43,410,072	43,229,087

Condensed Consolidated Statements of Comprehensive Loss (Unaudited) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement of Comprehensive Income [Abstract]
Net loss	$ (22,870,416)	$ (30,265,327)	$ (67,564,702)	$ (88,941,229)
Other comprehensive loss:
Unrealized gain (loss) on investment securities	96,312	(230,935)	97,724	419,288
Comprehensive loss	$ (22,774,104)	$ (30,496,262)	$ (67,466,978)	$ (88,521,941)

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($)	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Cash flows provided by (used in) operating activities
Net loss	$ (67,564,702)	$ (88,941,229)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	155,262	146,784
Share-based compensation expense	11,030,572	10,975,931
Issuance of common stock for services	143,159	171,059
Amortization of premiums on investment securities	401,056	420,275
Changes in operating assets and liabilities:
Accounts receivable	88,030	29,351
Prepaid expenses and other assets	(1,302,264)	3,997,852
Accounts payable	653,008	3,784,546
Accrued liabilities	653,169	5,641,847
Deferred rent	43,632	966,704
Net cash used in operating activities	(55,699,078)	(62,806,880)
Cash flows provided by (used in) investing activities
Purchases of investments	(274,674,730)	(320,098,309)
Maturities of investments	334,048,572	410,732,563
Purchases of property and equipment	(207,254)	(48,965)
Net cash provided by investing activities	59,166,588	90,585,289
Cash flows provided by financing activities
Proceeds from secured line of credit		125,000,000
Proceeds from stock option exercises	230,784	450,308
Net cash provided by financing activities	230,784	125,450,308
Net increase in cash and cash equivalents	3,698,294	153,228,717
Cash and cash equivalents at beginning of period	48,642,225	47,159,303
Cash and cash equivalents at end of period	$ 52,340,519	$ 200,388,020

Organization	9 Months Ended
Organization	Sep. 30, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization	1. Organization Intra-Cellular Therapies, Inc. (the “Company”), through its wholly-owned operating subsidiaries, ITI, Inc. (“ITI”) and ITI Limited, is a biopharmaceutical company focused on the discovery and clinical development of innovative, small molecule drugs that address underserved medical needs in neuropsychiatric and neurological disorders by targeting intracellular signaling mechanisms within the central nervous system (“CNS”). The Company’s lead product candidate, lumateperone, is in Phase 3 clinical development as a novel treatment for schizophrenia, bipolar depression and agitation associated with dementia, including Alzheimer’s disease. The Company was originally incorporated in the State of Delaware in August 2012 under the name “Oneida Resources Corp.” Prior to a reverse merger that occurred on August 29, 2013 (the “Merger”), Oneida Resources Corp. was a “shell” company registered under the Securities Exchange Act of 1934, as amended (the “Exchange Act”), with no specific business plan or purpose until it began operating the business of ITI, through the Merger transaction on August 29, 2013. ITI was incorporated in Delaware in May 2001 to focus primarily on the development of novel drugs for the treatment of neuropsychiatric and neurologic diseases and other disorders of the CNS. Effective upon the Merger, a wholly-owned subsidiary of the Company merged with and into ITI, and ITI continues as the operating subsidiary of the Company. In September 2016, the Company licensed certain intellectual property rights to its wholly-owned subsidiary, ITI Limited, which was formed in the third quarter of 2016. Although the license of intellectual property rights did not result in any gain or loss in the consolidated statements of operations, the $125 million of gain related to the transaction helped generate net taxable income for tax purposes in the U.S. and the Company utilized a portion of its available federal and state net operating loss carryforwards to offset the majority of this gain. Any taxes incurred related to intercompany transactions were treated as tax expense in the Company’s consolidated statement of operations. In addition to the license, the Company also entered into a research and development agreement with ITI Limited pursuant to which the Company will conduct research and development services related to the license agreement and charge ITI Limited for these services. On October 2, 2017 and October 5, 2017, the Company completed a public offering of common stock in which the Company sold 11,129,032 shares of common stock, which included the exercise of the underwriters’ option to purchase an additional 1,451,613 shares, at an offering price of $15.50 per share for aggregate gross proceeds of approximately $172 million. After deducting underwriting discounts, commissions and offering expenses, the net proceeds to the Company were approximately $162 million. In order to further its research projects and support its collaborations, the Company will require additional financing until such time, if ever, that revenue streams are sufficient to generate consistent positive cash flow from operations. Possible sources of funds include public or private sales of the Company’s equity securities, sales of debt securities, the incurrence of debt from commercial lenders, strategic collaborations, licensing a portion or all of the Company’s product candidates and technology and, to a lesser extent, grant funding. On September 2, 2016, the Company filed a universal shelf registration statement on Form S-3, which was declared effective by the Securities and Exchange Commission (the “SEC”) on September 14, 2016, on which the Company registered for sale up to $350 million of any combination of its common stock, preferred stock, debt securities, warrants, rights, purchase contracts and/or units from time to time and at prices and on terms that the Company may determine. After the public offering in October 2017, approximately $178 million of securities remain available for issuance under this shelf registration statement. This registration statement will remain in effect for up to three years from the initial effective date.

Summary of Significant Accounting Policies

9 Months Ended

Sep. 30, 2017

Accounting Policies [Abstract]

Summary of Significant Accounting Policies

2. Summary of Significant Accounting Policies

Basis of Presentation

The accompanying consolidated financial statements of Intra-Cellular Therapies, Inc. and its wholly own subsidiaries have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”). Any reference in these notes to applicable guidance is meant to refer to the authoritative United States generally accepted accounting principles set forth in the Accounting Standards Codification (“ASC”) and Accounting Standards Update (“ASU”) of the Financial Accounting Standards Board (“FASB”). All intercompany accounts and transactions have been eliminated in consolidation. The Company currently operates in one operating segment. Operating segments are defined as components of an enterprise about which separate discrete information is available for the chief operating decision maker, or decision making group, in deciding how to allocate resources and assessing performance. The Company views its operations and manages its business in one segment, which is discovering and developing drugs for the treatment of neurological and psychiatric disorders.

Use of Estimates

The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Although actual results could differ from those estimates, management does not believe that such differences would be material.

Cash and Cash Equivalents

The Company considers all highly liquid investments with a maturity of three months or less from the date of purchase to be cash equivalents. Cash and cash equivalents consist of checking accounts, money market accounts, money market mutual funds, and certificates of deposit with a maturity date of three months or less. The carrying values of cash and cash equivalents approximate the fair market value. Certificates of deposit, commercial paper, corporate notes and corporate bonds with a maturity date of more than three months are classified separately on the balance sheet.

Investment Securities

Investment securities consisted of the following (in thousands):


	September 30, 2017
	Amortized Cost		Unrealized Gains		Unrealized (Losses)			Estimated Fair Value
	(unaudited)
U.S. Government Agency Securities	$	89,980	$	—	$	(78	)	$	89,902
FDIC Certificates of Deposit (1)		12,555		—		—			12,555
Certificates of Deposit		13,500		—		—			13,500
Commercial Paper		40,730		1		(18	)		40,713
Corporate Notes/Bonds		119,236		5		(130	)		119,111

	$	276,001	$	6	$	(226	)	$	275,781


	December 31, 2016
	Amortized Cost		Unrealized Gains		Unrealized (Losses)			Estimated Fair Value
U.S. Government Agency Securities	$	67,199	$	1	$	(74	)	$	67,126
FDIC Certificates of Deposit (1)		20,740		1		—			20,741
Certificates of Deposit		64,500		—		—			64,500
Commercial Paper		67,352		11		(52	)		67,311
Corporate Notes/Bonds		115,985		—		(205	)		115,780

	$	335,776	$	13	$	(331	)	$	335,458

(1)	“FDIC Certificates of Deposit” consist of deposits that are less than $250,000.

The Company has classified all of its investment securities available-for-sale, including those with maturities beyond one year, as current assets on the consolidated balance sheets based on the highly liquid nature of the investment securities and because these investment securities are considered available for use in current operations. As of September 30, 2017 and December 31, 2016, the Company held $20.0 million and $47.9 million, respectively, of available-for-sale investment securities with contractual maturity dates more than one year and less than two years.

The Company monitors its investment portfolio for impairment quarterly or more frequently if circumstances warrant. In the event that the carrying value of an investment exceeds its fair value and the decline in value is determined to be other-than-temporary, the Company records an impairment charge within earnings attributable to the estimated credit loss. In determining whether a decline in the value of an investment is other-than-temporary, the Company evaluates currently available factors that may include, among others: (1) general market conditions; (2) the duration and extent to which fair value has been less than the carrying value; (3) the investment issuer’s financial condition and business outlook; and (4) the Company’s assessment as to whether it is more likely than not that the Company will be required to sell a security prior to recovery of its amortized cost basis.

As of September 30, 2017, the Company had approximately $41.3 million of investments that have been held for greater than one year which had a temporary impairment of approximately $41,000. As of December 31, 2016, the Company had approximately $25.5 million of investments that had been held for greater than one year which had a temporary impairment of approximately $25,000.

The Company attributes the unrealized losses on the available-for-sale securities as of September 30, 2017 and December 31, 2016 to the variability in related market interest rates. The Company does not intend to sell these securities, nor is it more likely than not that the Company will be required to sell them prior to the end of their contractual terms. Furthermore, the Company does not believe that these securities expose the Company to undue market risk or counterparty credit risk. As such, the Company does not consider these securities to be other-than-temporarily impaired.

Fair Value Measurements

The Company applies the fair value method under ASC Topic 820, Fair Value Measurements and Disclosures. ASC Topic 820 defines fair value, establishes a fair value hierarchy for assets and liabilities measured at fair value and requires expanded disclosures about fair value measurements. The ASC Topic 820 hierarchy ranks the quality and reliability of inputs, or assumptions, used in the determination of fair value and requires assets and liabilities carried at fair value to be classified and disclosed in one of the following categories based on the lowest level input used that is significant to a particular fair value measurement:

•

Level 1—Fair value is determined by using unadjusted quoted prices that are available in active markets for identical assets and liabilities.

•

Level 2—Fair value is determined by using inputs other than Level 1 quoted prices that are directly or indirectly observable. Inputs can include quoted prices for similar assets and liabilities in active markets or quoted prices for identical assets and liabilities in inactive markets. Related inputs can also include those used in valuation or other pricing models, such as interest rates and yield curves that can be corroborated by observable market data.

•

Level 3—Fair value is determined by inputs that are unobservable and not corroborated by market data. Use of these inputs involves significant and subjective judgments to be made by a reporting entity—e.g., determining an appropriate adjustment to a discount factor for illiquidity associated with a given security.

The Company evaluates financial assets and liabilities subject to fair value measurements on a recurring basis to determine the appropriate level at which to classify them each reporting period. This determination requires the Company to make subjective judgments as to the significance of inputs used in determining fair value and where such inputs lie within the ASC Topic 820 hierarchy.

The Company has no assets or liabilities that were measured using quoted prices for significant unobservable inputs (Level 3 assets and liabilities) as of September 30, 2017 and December 31, 2016. The carrying value of cash held in money market funds of approximately $21.5 million as of September 30, 2017 and $10.7 million as of December 31, 2016 is included in cash and cash equivalents and approximates market value based on quoted market price or Level 1 inputs.

The fair value measurements of the Company’s cash equivalents and available-for-sale investment securities are identified in the following tables (in thousands):


			Fair Value Measurements at Reporting Date Using
	September 30, 2017		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Money Market Funds	$	21,506	$	21,506	$	—	$	—
U.S. Government Agency Securities		89,902		—		89,902		—
FDIC Certificates of Deposit		12,555		—		12,555		—
Certificates of Deposit		26,000		—		26,000		—
Commercial Paper		40,713		—		40,713		—
Corporate Notes/Bonds		119,111		—		119,111		—

	$	309,787	$	21,506	$	288,281	$	—


			Fair Value Measurements at Reporting Date Using
	December 31, 2016		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Money Market Funds	$	10,724	$	10,724	$	—	$	—
U.S. Government Agency Securities		67,126		—		67,126		—
FDIC Certificates of Deposit		20,741		—		20,741		—
Certificates of Deposit		64,500		—		64,500		—
Commercial Paper		67,311		—		67,311		—
Corporate Notes/Bonds		115,780		—		115,780		—

	$	346,182	$	10,724	$	335,458	$	—

Financial Instruments

The Company considers the recorded costs of its financial assets and liabilities, which consist of cash equivalents, accounts receivable, prepaid expenses, accounts payable and accrued liabilities, to approximate their fair value because of their relatively short maturities at September 30, 2017 and December 31, 2016. Management believes that the risks associated with its financial instruments are minimal as the counterparties are various corporations, financial institutions and government agencies of high credit standing.

Concentration of Credit Risk

Cash equivalents are held with major financial institutions in the United States. Certificates of deposit held with banks may exceed the amount of insurance provided on such deposits. Generally, these deposits may be redeemed upon demand and, therefore, bear minimal risk.

Accounts Receivable

Accounts receivable that management has the intent and ability to collect are reported in the balance sheets at outstanding amounts, less an allowance for doubtful accounts. The Company writes off uncollectible receivables when the likelihood of collection is not probable.

The Company evaluates the collectability of accounts receivable on a regular basis. The allowance, if any, is based upon various factors including the financial condition and payment history of customers, an overall review of collections experience on other accounts and economic factors or events expected to affect future collections experience. No allowance was recorded as of September 30, 2017 and December 31, 2016, as the Company has a history of collecting on all of its accounts, including those with government agencies and collaborations funding its research.

Property and Equipment

Property and equipment is stated at cost and depreciated on a straight-line basis over estimated useful lives ranging from three to five years. Leasehold improvements are amortized using the straight-line method over the shorter of the estimated useful life of the assets or the term of the related lease. Expenditures for maintenance and repairs are charged to operations as incurred.

When indicators of possible impairment are identified, the Company evaluates the recoverability of the carrying value of its long-lived assets based on the criteria established in ASC Topic 360, Property, Plant and Equipment. The Company considers historical performance and anticipated future results in its evaluation of potential impairment. The Company evaluates the carrying value of those assets in relation to the operating performance of the business and undiscounted cash flows expected to result from the use of those assets. Impairment losses are recognized when carrying value exceeds the undiscounted cash flows, in which case management must determine the fair value of the underlying asset. No such impairment losses have been recognized to date.

Revenue Recognition

Revenue is recognized when all terms and conditions of the agreements have been met, including persuasive evidence of an arrangement, delivery has occurred or services have been rendered, price is fixed or determinable and collectability is reasonably assured. The Company is reimbursed for certain costs incurred on specified research projects under the terms and conditions of grants, collaboration agreements, and awards. The Company records the amount of reimbursement as revenues on a gross basis in accordance with ASC Topic 605-45, Revenue Recognition/Principal Agent Considerations. The Company is the primary obligor with respect to purchasing goods and services from third-party suppliers, is obligated to compensate the service provider for the work performed, and has discretion in selecting the supplier. Provisions for estimated losses on research grant projects and any other contracts are made in the period such losses are determined.

The Company has entered into arrangements involving the delivery of more than one element. Each required deliverable is evaluated to determine whether it qualifies as a separate unit of accounting. For the Company, this determination is generally based on whether the deliverable has “stand-alone value” to the customer. The Company adopted this accounting standard on a prospective basis for all Multiple-Deliverable Revenue Arrangements (“MDRAs”) entered into on or after January 1, 2011, and for any MDRAs that were entered into prior to January 1, 2011, but materially modified on or after that date.

The Company has adopted ASC Topic 605-28, Milestone Method. Under this guidance, the Company recognizes revenue contingent upon the achievement of a substantive milestone in its entirety in the period the milestone is achieved. Substantive milestone payments are recognized upon achievement of the milestone only if all of the following conditions are met:

•

The milestone payments are non-refundable;

•

Achievement of the milestone involves a degree of risk and was not reasonably assured at the inception of the arrangement;

•

Substantive effort on the Company’s part is involved in achieving the milestone;

•

The amount of the milestone payment is reasonable in relation to the effort expended or the risk associated with achievement of the milestone; and

•

A reasonable amount of time passes between the up-front license payment and the first milestone payment, as well as between each subsequent milestone payment.

Determination as to whether a payment meets the aforementioned conditions involves management’s judgment. If any of these conditions are not met, the resulting payment would not be considered a substantive milestone and, therefore, the resulting payment would be considered part of the consideration for the single unit of accounting and be recognized as revenue in accordance with the revenue models described above. In addition, the determination that one such payment was not a substantive milestone could prevent the Company from concluding that subsequent milestone payments were substantive milestones and, as a result, any additional milestone payments could also be considered part of the consideration for the single unit of accounting and would be recognized as revenue as such performance obligations are performed under either the proportional performance or straight-line methods, as applicable.

Research and Development

Except for payments made in advance of services, the Company expenses its research and development costs as incurred. For payments made in advance, the Company recognizes research and development expense as the services are rendered. Research and development costs primarily consist of salaries and related expenses for personnel and resources and the costs of clinical trials. Other research and development expenses include pre-clinical analytical testing, manufacturing of drug product, outside services, providers, materials and consulting fees.

Costs for certain development activities, such as clinical trials, are recognized based on an evaluation of the progress to completion of specific tasks using data such as subject enrollment, clinical site activations or information provided to the Company by its vendors with respect to their actual costs incurred. Payments for these activities are based on the terms of the individual arrangements, which may differ from the pattern of costs incurred, and are reflected in the financial statements as prepaid or accrued research and development expense, as the case may be.

As part of the process of preparing its financial statements, the Company is required to estimate its expenses resulting from its obligations under contracts with vendors, clinical research organizations and consultants and under clinical site agreements in connection with conducting clinical trials. The financial terms of these contracts are subject to negotiations, which vary from contract to contract and may result in payment flows that do not match the periods over which materials or services are provided under such contracts. The Company’s objective is to reflect the appropriate clinical trial expenses in its financial statements by matching those expenses with the period in which services are performed and efforts are expended. The Company accounts for these expenses according to the progress of the clinical trial as measured by subject progression and the timing of various aspects of the trial. The Company determines accrual estimates through financial models taking into account discussion with applicable personnel and outside service providers as to the progress or state of consummation of trials, or the services completed. During the course of a clinical trial, the Company adjusts its clinical expense recognition if actual results differ from its estimates. The Company makes estimates of its accrued expenses as of each balance sheet date based on the facts and circumstances known to it at that time. The Company’s clinical trial accruals are dependent upon the timely and accurate reporting of contract research organizations, clinical sites, and other third-party vendors. Although the Company does not expect its estimates to be materially different from amounts actually incurred, its understanding of the status and timing of services performed relative to the actual status and timing of services performed may vary and may result in it reporting amounts that are too high or too low for any particular period. For the three and nine months ended September 30, 2017 and 2016, there were no material adjustments to the Company’s prior period estimates of accrued expenses for clinical trials.

Income Taxes

Income taxes are accounted for using the liability method. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the year in which those temporary differences are expected to be recovered or settled.

The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. Valuation allowances are established when necessary to reduce net deferred tax assets to the amount expected to be realized. Income tax expense is the tax payable for the period and the change during the period in deferred tax assets and liabilities. The Company accounts for uncertain tax positions pursuant to ASC Topic 740 (previously included in FASB Interpretation No. 48, Accounting for Uncertainty in Income Taxes—an Interpretation of FASB Statement No. 109). Financial statement recognition of a tax position taken or expected to be taken in a tax return is determined based on a more-likely-than-not threshold of that position being sustained. If the tax position meets this threshold, the benefit to be recognized is measured as the tax benefit having the highest likelihood of being realized upon ultimate settlement with the taxing authority. The Company recognizes interest accrued related to unrecognized tax benefits and penalties in the provision for income taxes.

Comprehensive Income (Loss)

All components of comprehensive income (loss), including net income (loss), are reported in the financial statements in the period in which they are incurred. Comprehensive income (loss) is defined as the change in equity of a business enterprise during a period from transactions and other events and circumstances from non-owner sources. In accordance with accounting guidance, the Company presents the impact of any unrealized gains or (losses) on its investment securities in a separate statement of comprehensive income (loss) for each period.

Share-Based Compensation

Share-based payments are accounted for in accordance with the provisions of ASC Topic 718, Compensation—Stock Compensation. The fair value of share-based payments is estimated, on the date of grant, using the Black-Scholes-Merton option-pricing model (the “Black-Scholes model”). The resulting fair value is recognized ratably over the requisite service period, which is generally the vesting period of the option.

For all awards granted with time-based vesting conditions, expense is amortized using the straight-line attribution method. Share-based compensation expense recognized in the statements of operations for the three and nine months ended September 30, 2017 and 2016 is based on share-based awards ultimately expected to vest.

The Company utilizes the Black-Scholes model for estimating fair value of its stock options granted. Option valuation models, including the Black-Scholes model, require the input of subjective assumptions, and changes in the assumptions used can materially affect the grant date fair value of an award. These assumptions include the risk-free rate of interest, expected dividend yield, expected volatility and the expected life of the award.

Expected volatility rates are based on a combination of the historical volatility of the common stock of comparable publicly traded entities and the limited historical information about the Company’s common stock. The expected life of stock options is the period of time for which the stock options are expected to be outstanding. Given the limited historical exercise data, the expected life is determined using the “simplified method,” which defines expected life as the midpoint between the vesting date and the end of the contractual term.

The risk-free interest rates are based on the U.S. Treasury yield for a period consistent with the expected term of the option in effect at the time of the grant. The Company has not paid dividends to its stockholders since its inception and does not plan to pay cash dividends in the foreseeable future. Therefore, the Company has assumed an expected dividend rate of zero.

Prior to January 1, 2014, at which time there was no active market for the Company’s common stock, the exercise price of the stock options on the date of grant was determined and approved by the board of directors using several factors, including progress and milestones achieved in the Company’s business development and performance, the price per share of its convertible preferred stock offerings, and general industry and economic trends. In establishing the estimated fair value of the common stock, the Company considered the guidance set forth in American Institute of Certified Public Accountants Practice Guide, Valuation of Privately-Held-Company Equity Securities Issued as Compensation. For stock options granted on or after January 1, 2014, the exercise price was determined by using the closing market price of the Company’s common stock on the date of grant.

A restricted stock unit (“RSU”) is a stock award that entitles the holder to receive shares of the Company’s common stock as the award vests. The fair value of each RSU is based on the fair market value of the Company’s common stock on the date of grant. The Company has granted RSUs that vest in three equal annual installments provided that the employee remains employed with the Company.

Beginning in the first quarter of 2016, the Company granted time based RSUs that vest in three equal annual installments. In the first quarter of 2017, the Company granted additional time-based RSUs as well as performance-based RSUs, which vest based on the achievement of certain milestones that include (i) the submission of a new drug application (“NDA”) with the U.S. Food and Drug Administration (the “FDA”), (ii) the approval of the NDA by the FDA (the “Milestone RSU grants”) and (iii) the achievement of certain comparative shareholder returns against the Company’s peers (the “TSR RSU grants”). The Milestone RSU grants were valued at the closing price on March 8, 2017. The RSUs that vest upon the NDA submission will be amortized through December 31, 2018 based on the probable vesting date. The amortization of the expenses for RSUs related to the approval of the NDA will commence if and when the NDA filing has been approved through the last day of the calendar year in which the milestone is achieved. The TSR RSU grants were valued using the Monte Carlo Simulation method and will be amortized over the life of the RSU agreements which ends December 31, 2019. The Milestone RSU grants and TSR RSU grants are target based and the ultimate awards, if attained, could be the target amount or higher or lower than the target amount, depending on the timing or achievement of the goal. The Company is amortizing the expenses at the 100% targeted amount.

Under ASC Topic 718, the cumulative amount of compensation cost recognized for instruments classified as equity that ordinarily would result in a future tax deduction under existing tax law shall be considered to be a deductible difference in applying ASC Topic 740, Income Taxes. The deductible temporary difference is based on the compensation cost recognized for financial reporting purposes; however, these provisions currently do not impact the Company, as all the deferred tax assets have a full valuation allowance.

Since the Company had net operating loss carryforwards as of September 30, 2017 and 2016, no excess tax benefits for the tax deductions related to share-based awards were recognized in the statements of operations.

Equity instruments issued to non-employees for services are accounted for under the provisions of ASC Topic 718 and ASC Topic 505-50, Equity/Equity-Based Payments to Non-Employees. Accordingly, the estimated fair value of the equity instrument is recorded on the earlier of the performance commitment date or the date the required services are completed and are marked to market during the service period.

Loss Per Share

Basic net loss per common share is determined by dividing the net loss by the weighted-average number of common shares outstanding during the period, without consideration of common stock equivalents. Diluted net loss per share is computed by dividing the net loss by the weighted-average number of common stock equivalents outstanding for the period. The treasury stock method is used to determine the dilutive effect of the Company’s stock option grants and RSUs.

The following common stock equivalents were excluded in the calculation of diluted loss per share because their effect would be anti-dilutive as applied to the loss from operations for the three and nine months ended September 30, 2017 and 2016:

Three Months Ended

September 30,

Nine Months Ended

September 30,

2017

2016

2017

2016

Stock options

513,781

1,528,266

513,781

1,528,266

RSUs

84,640

39,420

83,710

38,844

Recently Issued Accounting Standards

In May 2014, the FASB issued ASC Update No. 2014-09, Revenue from Contracts with Customers (Topic 606), which has been subsequently updated. The purpose of Update No. 2014-09 is to provide enhancements to the quality and consistency of how revenue is reported while also improving comparability in the financial statements of companies using U.S. GAAP and International Financial Reporting Standards. The core principle requires entities to recognize revenue in a manner that depicts the transfer of goods or services to customers in amounts that reflect the consideration to which an entity expects to be entitled in exchange for those goods or services. FASB ASC Topic 606, as amended, becomes effective for annual periods beginning after December 15, 2017, at which point the Company plans to adopt the standard. The Company currently plans to adopt the standard using the “modified retrospective method.” Under that method, the Company will apply the standard to contracts whose performance has not been completed as of January 1, 2018, and recognize the cumulative effect of initially applying the standard as an adjustment to the opening balance of retained earnings.

The Company does not expect the adoption of this standard to result in a material impact to its financial statements. Upon adopting FASB ASC Topic 606, the Company will provide additional disclosures in the notes to the consolidated financial statements related to the relevant aspects of any revenue generating contracts that the Company has or into which the Company expects to enter.

In 2017, the Company is implementing new internal controls as part of its efforts to adopt the new revenue recognition standard. These internal controls include providing training to the Company’s finance team and holding regular meetings with the Company’s management and the Audit Committee of the Company’s Board of Directors to review and approve key decisions. Upon adoption, the Company expects to implement new internal controls related to its accounting policies and procedures. The Company will require new internal controls to address risks associated with applying the five-step model. Additionally, the Company will establish monitoring controls to identify sales arrangements and changes in the Company’s business environment that could impact its current accounting assessment. The Company expects to finalize its impact assessment and redesign impacted processes, policies and controls.

In January 2016, the FASB issued ASU No. 2016-01, Recognition and Measurement of Financial Assets and Financial Liabilities (“ASU 2016-01”). ASU 2016-01 eliminates the requirement to disclose the methods and significant assumptions used to estimate the fair value that is required to be disclosed for financial instruments measured at amortized cost on the balance sheet. The standard also clarifies the need to evaluate a valuation allowance on a deferred tax asset related to available-for-sale securities in combination with the Company’s other deferred tax assets. ASU 2016-01 is effective for annual reporting periods beginning after December 15, 2017. The adoption of this standard is not expected to have a material impact on the Company’s consolidated financial statements.

In February 2016, the FASB issued ASU No. 2016-02, Leases (“ASU 2016-02”). ASU 2016-02 allows the recognition of lease assets and lease liabilities by lessees for those leases classified as operating leases under previous GAAP. The classification criteria for distinguishing between finance leases and operating leases are substantially similar to the classification criteria for distinguishing between capital leases and operating leases in the previous leases guidance. ASU 2016-02 is effective for annual reporting periods beginning after December 15, 2018 and early adoption is permitted. The Company is currently analyzing the impact of ASU 2016-02 and, at this time, has not yet determined the impact of the new standard, if any, on the Company’s consolidated financial statements.

In March 2016, the FASB issued ASU No. 2016-09, Compensation—Stock Compensation (“ASU 2016-09”). ASU 2016-09 simplifies several areas of accounting for stock compensation, including simplification of the accounting for income taxes, classification of excess tax benefits on the Statement of Cash Flows and forfeitures. ASU 2016-09 is effective for annual reporting periods beginning after December 15, 2016. An entity that elects early adoption must adopt all of the amendments in the same period. The Company did not early adopt ASU 2016-09 as of and for the period ended December 31, 2016. As of January 1, 2017, the Company adopted ASU 2016-09 for the quarter ended March 31, 2017. Accordingly, the Company recognized previously unrecognized excess tax benefits of $7 million recorded as deferred tax assets with a corresponding offsetting full valuation allowance at the beginning of 2017, which yielded no tax impact.

Property and Equipment

9 Months Ended

Sep. 30, 2017

Property, Plant and Equipment [Abstract]

Property and Equipment

3. Property and Equipment

Property and equipment consist of the following:


	September 30, 2017			December 31, 2016
Computer equipment	$	33,584		$	39,095
Furniture and fixtures		292,423			292,423
Scientific equipment		2,987,778			2,844,865

		3,313,785			3,176,383

Less accumulated depreciation		(2,634,179	)		(2,548,769	)

	$	679,606		$	627,614

Depreciation expense for the nine months ended September 30, 2017 and 2016 was $155,262 and $146,784, respectively.

Share-Based Compensation

9 Months Ended

Sep. 30, 2017

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Share-Based Compensation

4. Share-Based Compensation

The Company’s Amended and Restated 2013 Equity Incentive Plan (the “Plan”) provides for the granting of stock-based awards, such as stock options, restricted common stock, RSUs and stock appreciation rights to employees, directors and consultants as determined by the Board of Directors. As of December 31, 2016, there were options to purchase 3,101,032 shares of common stock outstanding under the Plan. On June 16, 2015, the stockholders of the Company approved, at the Company’s 2015 Annual Meeting of Stockholders, an amendment to the Plan to increase the number of shares of common stock available for issuance under the plan by 3,100,000 shares, to increase by 100,000 shares the maximum number of shares available for the issuance of options, stock appreciation rights and other similar awards to any one participant in any calendar year for purposes of meeting the requirements for qualified performance-based compensation under Section 162(m) of the Internal Revenue Code of 1986, as amended (the “Code”), and to eliminate the evergreen provisions of the Plan under which 800,000 shares were automatically added to the plan on each of January 1, 2014 and 2015. Stock options granted under the Plan may be either incentive stock options (“ISOs”) as defined by the Code, or non-qualified stock options. The Board of Directors determines who will receive options, the vesting periods (which are generally two to three years) and the exercise prices of such options. Options have a maximum term of 10 years. The exercise price of ISOs granted under the Plan must be at least equal to the fair market value of the common stock on the date of grant.

Total stock-based compensation expense related to all of the Company’s share-based awards including stock options and RSUs to employees, directors and consultants recognized during three and nine months ended September 30, 2017 and 2016, was comprised of the following:


	Three Months Ended September 30,				Nine Months Ended September 30,
	2017		2016		2017		2016
Research and development	$	753,566	$	1,045,547	$	3,668,464	$	3,400,324
General and administrative		1,747,187		2,641,199		7,362,108		7,575,607

Total share-based compensation expense	$	2,500,753	$	3,686,746	$	11,030,572	$	10,975,931

The following table describes the weighted-average assumptions used for calculating the value of options granted during the nine months ended September 30, 2017 and September 30, 2016:


	2017			2016
Dividend yield		0	%		0	%
Expected volatility		87.4%-90.4	%		80	%
Weighted-average risk-free interest rate		2.1	%		1.7	%
Expected term		5.9 years			5.9 years

Information regarding the stock options activity, including with respect to grants to employees, directors and consultants as of September 30, 2017 and changes during the nine-month period then ended, are summarized as follows:


	Number of Shares			Weighted- Average Exercise Price Per Share		Weighted- Average Contractual Life
Outstanding at December 31, 2016 (audited)		3,101,032		$	19.63	7.2 years
Options granted (unaudited)		738,195		$	15.21	9.3 years
Options exercised (unaudited)		(99,750	)	$	2.55	3.4 years
Options canceled or expired (unaudited)		(128,830	)	$	25.83	8.5 years

Outstanding at September 30, 2017 (unaudited)		3,610,647		$	18.97	7.0 years

Vested or expected to vest at September 30, 2017 (unaudited)		3,610,647		$	18.97

Exercisable at September 30, 2017 (unaudited)		2,451,396		$	16.69	6.4 years

The fair value of an RSU is based on the closing price of the Company’s stock on the date of grant. Information regarding RSU activity, including with respect to grants to employees as of September 30, 2017 and changes during the nine-month period then ended, are summarized as follows:


	Number of Shares			Weighted-Average Grant Date Fair Value Per Share
Outstanding at December 31, 2016 (audited)		82,321		$	53.77
RSU’s granted in 2017 (unaudited)		154,922		$	15.73
RSU’s vested in 2017 (unaudited)		(26,256	)	$	53.63

RSU’s cancelled in 2017 (unaudited)		(18,297	)	$	26.80

Outstanding at September 30, 2017 (unaudited)		192,690		$	25.77

Information related to the Company’s Milestone RSU grants and the TSR RSU grants during the nine-month period ended September 30, 2017 are summarized as follows:


	Number of Shares			Weighted-Average Grant Date Fair Value Per Share
Outstanding at December 31, 2016 (unaudited)		—		$	—
RSU’s granted in 2017 (unaudited)		454,644		$	15.15

RSU’s cancelled in 2017 (unaudited)		(38,838	)	$	15.15

Outstanding at September 30, 2017 (unaudited)		415,806		$	15.15

The weighted average estimated fair value per share of the TSR RSUs granted in the nine months ended September 30, 2017 was $17.08, which was derived from a Monte Carlo simulation. Significant assumptions utilized in estimating the value of the awards granted include an expected dividend yield of 0%, a risk free rate of 1.6%, and expected volatility of 95.4%. The TSR RSUs granted in the nine months ended September 30, 2017, will entitle the grantee to receive a number of shares of the Company’s common stock determined over a three-year performance period ending and vesting on December 31, 2019, provided the grantee remains in the service of the Company on the settlement date. The Company expenses the cost of these awards ratably over the requisite service period. The number of shares for which the TSR RSUs will be settled will be a percentage of shares for which the award is targeted and will depend on the Company’s total shareholder return (as defined below), expressed as a percentile ranking of the Company’s total shareholder return as compared to the Company’s peer group (as defined below). The number of shares for which the TSR RSUs will be settled vary depending on the level of achievement of the goal. Total shareholder return is determined by dividing the average share value of the Company’s common stock over the 30 trading days preceding January 1, 2020 by the average share value of the Company’s common stock over the 30 trading days beginning on March 8, 2017, with a deemed reinvestment of any dividends declared during the performance period. The Company’s peer group includes 162 companies which comprise the Nasdaq Biotechnology Index, which was selected by the Compensation Committee of the Company’s Board of Directors and includes a range of biotechnology companies operating in several business segments.

The Company recognized non-cash stock-based compensation expense related to time based RSU’s for the three and nine months ending September 30, 2017 of approximately $368,000 and $1.5 million, respectively, as compared to $361,000 and $1.1 million, respectively, for the three and nine months ending September 30, 2016. As of September 30, 2017, there was $3.5 million of unrecognized compensation costs related to unvested time-based RSUs. Total expense for all RSUs, including the time-based and performance-based RSU grants for the three and nine months ending September 30, 2017 is approximately $787,000 and $2.6 million, respectively, as compared to $361,000 and $1.1 million, respectively, for the three and nine months ending September 30, 2016. As of September 30, 2017, there was $5.4 million of unrecognized compensation costs related to unvested Milestone RSU grants and TSR RSU grants.

Line of Credit	9 Months Ended
Line of Credit	Sep. 30, 2017
Debt Disclosure [Abstract]
Line of Credit	5. Line of Credit On September 30, 2016, the Company entered into a secured line of credit with a lender for an amount not to exceed $150.8 million. This line of credit was secured by approximately $150.8 million of collateral held by the lender. The interest on advances under this line of credit was fixed at LIBOR plus 2.991% on the date of advance. The Company borrowed $125.0 million on September 30, 2016 and repaid the entire amount on October 3, 2016. Interest expense under this secured line of credit was $12,260 for the quarter ended September 30, 2016. On October 6, 2016, the line of credit was terminated by the Company. The fair value of this line of credit was $125.0 million on September 30, 2016.

Collaborations and License Agreements	9 Months Ended
Collaborations and License Agreements	Sep. 30, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Collaborations and License Agreements	6. Collaborations and License Agreements The Bristol-Myers Squibb License Agreement On May 31, 2005, the Company entered into a worldwide, exclusive License Agreement with Bristol-Myers Squibb Company (“BMS”), pursuant to which the Company holds a license to certain patents and know-how of BMS relating to lumateperone and other specified compounds. The agreement was amended on November 3, 2010. The licensed rights are exclusive, except BMS retains rights in specified compounds in the fields of obesity, diabetes, metabolic syndrome and cardiovascular disease. However, BMS has no right to use, develop or commercialize lumateperone and other specified compounds in any field of use. The Company has the right to grant sublicenses of the rights conveyed by BMS. The Company is obliged under the agreement to use commercially reasonable efforts to develop and commercialize the licensed technology. The Company is also prohibited from engaging in the clinical development or commercialization of specified competitive compounds. Under the agreement, the Company made an upfront payment of $1.0 million to BMS, a milestone payment of $1.25 million in December 2013, and a milestone payment of $1.5 million in December 2014 following the initiation of the Company’s first Phase 3 clinical trial for lumateperone for patients with exacerbated schizophrenia. Possible milestone payments remaining total $12.0 million. Under the agreement, the Company may be obliged to make other milestone payments to BMS for each licensed product of up to an aggregate of approximately $14.75 million. The Company is also obliged to make tiered single digit percentage royalty payments on sales of licensed products. The Company is obliged to pay to BMS a percentage of non-royalty payments made in consideration of any sublicense. The agreement extends, and royalties are payable, on a country-by-country and product-by-product basis, through the later of ten years after first commercial sale of a licensed product in such country, expiration of the last licensed patent covering a licensed product, its method of manufacture or use, or the expiration of other government grants providing market exclusivity, subject to certain rights of the parties to terminate the agreement on the occurrence of certain events. On termination of the agreement, the Company may be obliged to convey to BMS rights in developments relating to a licensed compound or licensed product, including regulatory filings, research results and other intellectual property rights. In September 2016, the Company transferred certain of its rights under the agreement to its wholly owned subsidiary, ITI Limited. In connection with the transfer, the Company guaranteed ITI Limited’s performance of its obligations under the agreement.

Legal Matters	9 Months Ended
Legal Matters	Sep. 30, 2017
Commitments and Contingencies Disclosure [Abstract]
Legal Matters	7. Legal Matters On May 12, 2017, a purported class action lawsuit was filed against the Company and certain of its executive officers alleging violations of the Exchange Act and Rule 10b-5 promulgated thereunder. On May 26, 2017, a second purported class action lawsuit was filed against the Company and certain of its executive officers alleging violations of the Exchange Act and Rule 10b-5 promulgated thereunder. Each of these lawsuits was premised upon allegations that the defendants made false and misleading statements and/or omissions by failing to earlier disclose findings related to toxicity in animals treated with lumateperone. Additionally, the complaints alleged that, as a result of the foregoing, certain of the defendants’ statements about the Company’s business, operations, and prospects were materially false and misleading and/or lacked a reasonable basis. In July 2017, these two actions were consolidated into a single action and a purported individual investor in the Company was appointed as lead plaintiff to represent the proposed class. In September 2017, the parties filed a request that the consolidated action be voluntarily dismissed without prejudice. On November 2, 2017, the United States District Court for the Eastern District of New York granted the parties’ request to dismiss the action. The matter has now concluded.

Summary of Significant Accounting Policies (Policies)

9 Months Ended

Sep. 30, 2017

Accounting Policies [Abstract]

Basis of Presentation

Basis of Presentation

Use of Estimates

Use of Estimates

Cash and Cash Equivalents

Cash and Cash Equivalents

Investment Securities

Investment Securities

Investment securities consisted of the following (in thousands):


	September 30, 2017
	Amortized Cost		Unrealized Gains		Unrealized (Losses)			Estimated Fair Value
	(unaudited)
U.S. Government Agency Securities	$	89,980	$	—	$	(78	)	$	89,902
FDIC Certificates of Deposit (1)		12,555		—		—			12,555
Certificates of Deposit		13,500		—		—			13,500
Commercial Paper		40,730		1		(18	)		40,713
Corporate Notes/Bonds		119,236		5		(130	)		119,111

	$	276,001	$	6	$	(226	)	$	275,781


	December 31, 2016
	Amortized Cost		Unrealized Gains		Unrealized (Losses)			Estimated Fair Value
U.S. Government Agency Securities	$	67,199	$	1	$	(74	)	$	67,126
FDIC Certificates of Deposit (1)		20,740		1		—			20,741
Certificates of Deposit		64,500		—		—			64,500
Commercial Paper		67,352		11		(52	)		67,311
Corporate Notes/Bonds		115,985		—		(205	)		115,780

	$	335,776	$	13	$	(331	)	$	335,458

(1)	“FDIC Certificates of Deposit” consist of deposits that are less than $250,000.

Fair Value Measurements

Fair Value Measurements

•

Level 1—Fair value is determined by using unadjusted quoted prices that are available in active markets for identical assets and liabilities.

•

The fair value measurements of the Company’s cash equivalents and available-for-sale investment securities are identified in the following tables (in thousands):


			Fair Value Measurements at Reporting Date Using
	September 30, 2017		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Money Market Funds	$	21,506	$	21,506	$	—	$	—
U.S. Government Agency Securities		89,902		—		89,902		—
FDIC Certificates of Deposit		12,555		—		12,555		—
Certificates of Deposit		26,000		—		26,000		—
Commercial Paper		40,713		—		40,713		—
Corporate Notes/Bonds		119,111		—		119,111		—

	$	309,787	$	21,506	$	288,281	$	—


			Fair Value Measurements at Reporting Date Using
	December 31, 2016		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Money Market Funds	$	10,724	$	10,724	$	—	$	—
U.S. Government Agency Securities		67,126		—		67,126		—
FDIC Certificates of Deposit		20,741		—		20,741		—
Certificates of Deposit		64,500		—		64,500		—
Commercial Paper		67,311		—		67,311		—
Corporate Notes/Bonds		115,780		—		115,780		—

	$	346,182	$	10,724	$	335,458	$	—

Financial Instruments

Financial Instruments

Concentration of Credit Risk

Concentration of Credit Risk

Accounts Receivable

Accounts Receivable

Property and Equipment

Property and Equipment

Revenue Recognition

Revenue Recognition

•

The milestone payments are non-refundable;

•

Achievement of the milestone involves a degree of risk and was not reasonably assured at the inception of the arrangement;

•

Substantive effort on the Company’s part is involved in achieving the milestone;

•

The amount of the milestone payment is reasonable in relation to the effort expended or the risk associated with achievement of the milestone; and

•

A reasonable amount of time passes between the up-front license payment and the first milestone payment, as well as between each subsequent milestone payment.

Research and Development

Research and Development

Income Taxes

Income Taxes

Comprehensive Income (Loss)

Comprehensive Income (Loss)

Share-Based Compensation

Share-Based Compensation

Loss Per Share

Loss Per Share

Three Months Ended

September 30,

Nine Months Ended

September 30,

2017

2016

2017

2016

Stock options

513,781

1,528,266

513,781

1,528,266

RSUs

84,640

39,420

83,710

38,844

Recently Issued Accounting Standards

Recently Issued Accounting Standards

Summary of Significant Accounting Policies (Tables)

9 Months Ended

Sep. 30, 2017

Accounting Policies [Abstract]

Schedule of Investment Securities

Investment securities consisted of the following (in thousands):


	September 30, 2017
	Amortized Cost		Unrealized Gains		Unrealized (Losses)			Estimated Fair Value
	(unaudited)
U.S. Government Agency Securities	$	89,980	$	—	$	(78	)	$	89,902
FDIC Certificates of Deposit (1)		12,555		—		—			12,555
Certificates of Deposit		13,500		—		—			13,500
Commercial Paper		40,730		1		(18	)		40,713
Corporate Notes/Bonds		119,236		5		(130	)		119,111

	$	276,001	$	6	$	(226	)	$	275,781


	December 31, 2016
	Amortized Cost		Unrealized Gains		Unrealized (Losses)			Estimated Fair Value
U.S. Government Agency Securities	$	67,199	$	1	$	(74	)	$	67,126
FDIC Certificates of Deposit (1)		20,740		1		—			20,741
Certificates of Deposit		64,500		—		—			64,500
Commercial Paper		67,352		11		(52	)		67,311
Corporate Notes/Bonds		115,985		—		(205	)		115,780

	$	335,776	$	13	$	(331	)	$	335,458

(1)	“FDIC Certificates of Deposit” consist of deposits that are less than $250,000.

Schedule of Fair Value Measurements of Cash Equivalents and Available-for-Sale Investment Securities

The fair value measurements of the Company’s cash equivalents and available-for-sale investment securities are identified in the following tables (in thousands):


			Fair Value Measurements at Reporting Date Using
	September 30, 2017		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Money Market Funds	$	21,506	$	21,506	$	—	$	—
U.S. Government Agency Securities		89,902		—		89,902		—
FDIC Certificates of Deposit		12,555		—		12,555		—
Certificates of Deposit		26,000		—		26,000		—
Commercial Paper		40,713		—		40,713		—
Corporate Notes/Bonds		119,111		—		119,111		—

	$	309,787	$	21,506	$	288,281	$	—


			Fair Value Measurements at Reporting Date Using
	December 31, 2016		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Money Market Funds	$	10,724	$	10,724	$	—	$	—
U.S. Government Agency Securities		67,126		—		67,126		—
FDIC Certificates of Deposit		20,741		—		20,741		—
Certificates of Deposit		64,500		—		64,500		—
Commercial Paper		67,311		—		67,311		—
Corporate Notes/Bonds		115,780		—		115,780		—

	$	346,182	$	10,724	$	335,458	$	—

Common Stock Equivalents Excluded in Calculation of Diluted Loss Per Share

Three Months Ended

September 30,

Nine Months Ended

September 30,

2017

2016

2017

2016

Stock options

513,781

1,528,266

513,781

1,528,266

RSUs

84,640

39,420

83,710

38,844

- Definition

Tabular disclosure of available-for-sale securities which includes, but is not limited to, changes in the cost basis and fair value, fair value and gross unrealized gain (loss), fair values by type of security, contractual maturity and classification, amortized cost basis, contracts to acquire securities to be accounted for as available-for-sale, debt maturities, transfers to trading, change in net unrealized holding gain (loss) net of tax, continuous unrealized loss position fair value, aggregate losses qualitative disclosures, other than temporary impairment (OTTI) losses or other disclosures related to available for sale securities.

+ References + Details

Property and Equipment (Tables)

9 Months Ended

Sep. 30, 2017

Property, Plant and Equipment [Abstract]

Property and Equipment

Property and equipment consist of the following:


	September 30, 2017			December 31, 2016
Computer equipment	$	33,584		$	39,095
Furniture and fixtures		292,423			292,423
Scientific equipment		2,987,778			2,844,865

		3,313,785			3,176,383

Less accumulated depreciation		(2,634,179	)		(2,548,769	)

	$	679,606		$	627,614

Share-Based Compensation (Tables)

9 Months Ended

Sep. 30, 2017

Total Stock-Based Compensation Expense


	Three Months Ended September 30,				Nine Months Ended September 30,
	2017		2016		2017		2016
Research and development	$	753,566	$	1,045,547	$	3,668,464	$	3,400,324
General and administrative		1,747,187		2,641,199		7,362,108		7,575,607

Total share-based compensation expense	$	2,500,753	$	3,686,746	$	11,030,572	$	10,975,931

Weighted-Average Assumptions Used for Calculating Value of Options Granted

The following table describes the weighted-average assumptions used for calculating the value of options granted during the nine months ended September 30, 2017 and September 30, 2016:


	2017			2016
Dividend yield		0	%		0	%
Expected volatility		87.4%-90.4	%		80	%
Weighted-average risk-free interest rate		2.1	%		1.7	%
Expected term		5.9 years			5.9 years

Stock Option Activity


	Number of Shares			Weighted- Average Exercise Price Per Share		Weighted- Average Contractual Life
Outstanding at December 31, 2016 (audited)		3,101,032		$	19.63	7.2 years
Options granted (unaudited)		738,195		$	15.21	9.3 years
Options exercised (unaudited)		(99,750	)	$	2.55	3.4 years
Options canceled or expired (unaudited)		(128,830	)	$	25.83	8.5 years

Outstanding at September 30, 2017 (unaudited)		3,610,647		$	18.97	7.0 years

Vested or expected to vest at September 30, 2017 (unaudited)		3,610,647		$	18.97

Exercisable at September 30, 2017 (unaudited)		2,451,396		$	16.69	6.4 years

RSUs [Member]

Summary of Information Regarding RSU Activity

Information regarding RSU activity, including with respect to grants to employees as of September 30, 2017 and changes during the nine-month period then ended, are summarized as follows:


	Number of Shares			Weighted-Average Grant Date Fair Value Per Share
Outstanding at December 31, 2016 (audited)		82,321		$	53.77
RSU’s granted in 2017 (unaudited)		154,922		$	15.73
RSU’s vested in 2017 (unaudited)		(26,256	)	$	53.63

RSU’s cancelled in 2017 (unaudited)		(18,297	)	$	26.80

Outstanding at September 30, 2017 (unaudited)		192,690		$	25.77

Milestone and Total Shareholder Return Restricted Stock Units [Member]

Summary of Information Regarding RSU Activity

Information related to the Company’s Milestone RSU grants and the TSR RSU grants during the nine-month period ended September 30, 2017 are summarized as follows:


	Number of Shares			Weighted-Average Grant Date Fair Value Per Share
Outstanding at December 31, 2016 (unaudited)		—		$	—
RSU’s granted in 2017 (unaudited)		454,644		$	15.15

RSU’s cancelled in 2017 (unaudited)		(38,838	)	$	15.15

Outstanding at September 30, 2017 (unaudited)		415,806		$	15.15

Organization - Additional Information (Detail) - USD ($)		9 Months Ended
	Oct. 05, 2017	Sep. 30, 2017	Oct. 30, 2017	Sep. 14, 2016
Subsequent Event [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Securities remained available for issuance under the Company's shelf registration			$ 178,000,000
IPO [Member] \| Subsequent Event [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Initial public offering, Number of shares	11,129,032
Initial public offering, Price per share	$ 15.50
Initial public offering, Gross proceeds	$ 172,000,000
Initial public offering, Net proceeds	$ 162,000,000
Over-Allotment Option [Member] \| Subsequent Event [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Initial public offering, Number of shares	1,451,613
ITI Limited [Member] \| Intellectual Property [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Finite lived intangible assets transactional gain		$ 125,000,000
Maximum [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Universal shelf registration statement, effective date value				$ 350,000,000

Summary of Significant Accounting Policies - Additional Information (Detail)	3 Months Ended	9 Months Ended		12 Months Ended
	Mar. 31, 2016	Sep. 30, 2017 USD ($) Segment	Sep. 30, 2016 USD ($)	Dec. 31, 2016 USD ($)
Significant Accounting Policies [Line Items]
Number of operating segments \| Segment		1
Maturity of highly liquid investments		3 months
Maturity of certificates of deposit, commercial paper, corporate notes and corporate bonds		More than three months
Investment securities, available-for-sale		$ 275,781,285		$ 335,458,459
Investment securities, available for sale noncurrent		41,300,000		25,500,000
Investment securities, unrealized loss		41,000		25,000
Carrying value of cash held in money market funds		21,500,000		10,700,000
Allowance for accounts receivable		0		0
Impairment losses recognized		$ 0
Assumed expected dividend rate		0.00%	0.00%
Excess tax benefits for tax deductions		$ 0	$ 0
Significant Unobservable Inputs (Level 3) [Member]
Significant Accounting Policies [Line Items]
Assets measured using quoted prices		0		0
Liabilities measured using quoted prices		0		0
Adjustments for New Accounting Pronouncement [Member]
Significant Accounting Policies [Line Items]
Deferred tax assets		7,000,000
Contractual Maturity Dates More Than One Year and Less Than Two Years [Member]
Significant Accounting Policies [Line Items]
Investment securities, available-for-sale		$ 20,000,000		$ 47,900,000
RSUs [Member]
Significant Accounting Policies [Line Items]
Service period for granted RSUs, vest in annual installment	3 years	3 years
Percentage of amortization expenses	100.00%
Minimum [Member]
Significant Accounting Policies [Line Items]
Property and equipment, estimated useful life		3 years
Maximum [Member]
Significant Accounting Policies [Line Items]
Property and equipment, estimated useful life		5 years

Summary of Significant Accounting Policies - Schedule of Investment Securities (Detail) - USD ($)	Sep. 30, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 276,001,000	$ 335,776,000
Unrealized Gains	6,000	13,000
Unrealized (Losses)	(226,000)	(331,000)
Estimated Fair Value	275,781,285	335,458,459
FDIC Certificates of Deposit [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	12,555,000	20,740,000
Unrealized Gains		1,000
Estimated Fair Value	12,555,000	20,741,000
U.S. Government Agency Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	89,980,000	67,199,000
Unrealized Gains		1,000
Unrealized (Losses)	(78,000)	(74,000)
Estimated Fair Value	89,902,000	67,126,000
Certificates of Deposit [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	13,500,000	64,500,000
Estimated Fair Value	13,500,000	64,500,000
Commercial Paper [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	40,730,000	67,352,000
Unrealized Gains	1,000	11,000
Unrealized (Losses)	(18,000)	(52,000)
Estimated Fair Value	40,713,000	67,311,000
Corporate Notes/Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	119,236,000	115,985,000
Unrealized Gains	5,000
Unrealized (Losses)	(130,000)	(205,000)
Estimated Fair Value	$ 119,111,000	$ 115,780,000

Summary of Significant Accounting Policies - Schedule of Investment Securities (Parenthetical) (Detail) - USD ($)	Sep. 30, 2017	Dec. 31, 2016
FDIC Certificates of Deposit [Member] \| Maximum [Member]
Schedule of Available-for-sale Securities [Line Items]
Deposits under FDIC Certificates of Deposit	$ 250,000	$ 250,000

Summary of Significant Accounting Policies - Schedule of Fair Value Measurements of Cash Equivalents and Available-for-Sale Investment Securities (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Available-for-sale investment securities	$ 309,787	$ 346,182
Money Market Funds [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Available-for-sale investment securities	21,506	10,724
U.S. Government Agency Securities [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Available-for-sale investment securities	89,902	67,126
FDIC Certificates of Deposit [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Available-for-sale investment securities	12,555	20,741
Certificates of Deposit [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Available-for-sale investment securities	26,000	64,500
Commercial Paper [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Available-for-sale investment securities	40,713	67,311
Corporate Notes/Bonds [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Available-for-sale investment securities	119,111	115,780
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Available-for-sale investment securities	21,506	10,724
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] \| Money Market Funds [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Available-for-sale investment securities	21,506	10,724
Significant Other Observable Inputs (Level 2) [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Available-for-sale investment securities	288,281	335,458
Significant Other Observable Inputs (Level 2) [Member] \| U.S. Government Agency Securities [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Available-for-sale investment securities	89,902	67,126
Significant Other Observable Inputs (Level 2) [Member] \| FDIC Certificates of Deposit [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Available-for-sale investment securities	12,555	20,741
Significant Other Observable Inputs (Level 2) [Member] \| Certificates of Deposit [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Available-for-sale investment securities	26,000	64,500
Significant Other Observable Inputs (Level 2) [Member] \| Commercial Paper [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Available-for-sale investment securities	40,713	67,311
Significant Other Observable Inputs (Level 2) [Member] \| Corporate Notes/Bonds [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Available-for-sale investment securities	$ 119,111	$ 115,780

Summary of Significant Accounting Policies - Common Stock Equivalents Excluded in Calculation of Diluted Loss Per Share (Detail) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Number of anti-dilutive securities excluded from computation of earnings per share	513,781	1,528,266	513,781	1,528,266
RSUs [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Number of anti-dilutive securities excluded from computation of earnings per share	84,640	39,420	83,710	38,844

Property and Equipment - Property and Equipment (Detail) - USD ($)	Sep. 30, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Property plant and equipment, gross	$ 3,313,785	$ 3,176,383
Less accumulated depreciation	(2,634,179)	(2,548,769)
Property Plant and Equipment Net	679,606	627,614
Computer Equipment [Member]
Property, Plant and Equipment [Line Items]
Property plant and equipment, gross	33,584	39,095
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Property plant and equipment, gross	292,423	292,423
Scientific Equipment [Member]
Property, Plant and Equipment [Line Items]
Property plant and equipment, gross	$ 2,987,778	$ 2,844,865

Property and Equipment - Additional Information (Detail) - USD ($)	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Property, Plant and Equipment [Abstract]
Depreciation expense	$ 155,262	$ 146,784

Share-Based Compensation - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of stock options outstanding	3,610,647		3,610,647		3,101,032
Expected dividend yield			0.00%	0.00%
Risk free interest rate			2.10%	1.70%
Expected volatility				80.00%
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options, maximum term			10 years
Stock Options [Member] \| Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Incentive stock options (ISOs), vesting period			2 years
Stock Options [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Incentive stock options (ISOs), vesting period			3 years
Total Shareholder Return Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Incentive stock options (ISOs), vesting period			3 years
Weighted average grant date fair value of stock options granted			$ 17.08
Expected dividend yield			0.00%
Risk free interest rate			1.60%
Expected volatility			95.40%
Vesting date			Dec. 31, 2019
Terms of award			Total shareholder return is determined by dividing the average share value of the Company's common stock over the 30 trading days preceding January 1, 2020 by the average share value of the Company's common stock over the 30 trading days beginning on March 8, 2017, with a deemed reinvestment of any dividends declared during the performance period.
Time Based Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Non-cash stock-based compensation expense recognized	$ 368,000	$ 361,000	$ 1,500,000	$ 1,100,000
Unrecognized compensation costs related to unvested RSUs	3,500,000		3,500,000
RSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Non-cash stock-based compensation expense recognized	787,000	$ 361,000	2,600,000	$ 1,100,000
Milestone and Total Shareholder Return Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation costs related to unvested RSUs	$ 5,400,000		$ 5,400,000
2013 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of stock options outstanding					3,101,032
Number of shares of common stock available for issuance under the plan	3,100,000		3,100,000
Increase in maximum number of shares available for issuance of options, stock appreciation rights and other similar awards			100,000

Share-Based Compensation - Total Stock-Based Compensation Expense (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total share-based compensation expense	$ 2,500,753	$ 3,686,746	$ 11,030,572	$ 10,975,931
Research and Development [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total share-based compensation expense	753,566	1,045,547	3,668,464	3,400,324
General and Administrative [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total share-based compensation expense	$ 1,747,187	$ 2,641,199	$ 7,362,108	$ 7,575,607

Share-Based Compensation - Weighted-Average Assumptions Used for Calculating Value of Options Granted (Detail)	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Dividend yield	0.00%	0.00%
Expected volatility		80.00%
Expected volatility, minimum	87.40%
Expected volatility, maximum	90.40%
Weighted-average risk-free interest rate	2.10%	1.70%
Expected term	5 years 10 months 25 days	5 years 10 months 25 days

Share-Based Compensation - Stock Options Activity (Detail) - $ / shares	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Outstanding at beginning of period, Number of Shares	3,101,032
Options granted, Number of Shares	738,195
Options exercised, Number of Shares	(99,750)
Options canceled or expired, Number of Shares	(128,830)
Outstanding at end of period, Number of Shares	3,610,647	3,101,032
Vested or expected to vest at end of period, Number of Shares	3,610,647
Exercisable at end of period, Number of Shares	2,451,396
Outstanding at beginning of period, Weighted-Average Exercise Price	$ 19.63
Options granted, Weighted-Average Exercise Price	15.21
Options exercised, Weighted-Average Exercise Price	2.55
Options canceled or expired, Weighted-Average Exercise Price	25.83
Outstanding at end of period, Weighted-Average Exercise Price	18.97	$ 19.63
Vested or expected to vest at end of period, Weighted-Average Exercise Price	18.97
Exercisable at end of period, Weighted-Average Exercise Price	$ 16.69
Options granted, Weighted-Average Contractual Life	9 years 3 months 18 days
Options exercised, Weighted-Average Contractual Life	3 years 4 months 24 days
Options canceled or expired, Weighted-Average Contractual Life	8 years 6 months
Outstanding at end of period, Weighted-Average Contractual Life	7 years	7 years 2 months 12 days
Exercisable at end of period, Weighted-Average Contractual Life	6 years 4 months 25 days

Share-Based Compensation - Summary of Information Regarding RSU Activity (Detail) - RSUs [Member]	9 Months Ended
	Sep. 30, 2017 $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding at beginning of period, Number of Shares \| shares	82,321
RSU's granted, Number of Shares \| shares	154,922
RSU's vested, Number of Shares \| shares	(26,256)
RSU's cancelled, Number of Shares \| shares	(18,297)
Outstanding at end of period, Number of Shares \| shares	192,690
Outstanding at beginning of period, Weighted-Average Grant Date Fair Value \| $ / shares	$ 53.77
RSU's granted, Weighted-Average Grant Date Fair Value \| $ / shares	15.73
RSU's vested, Weighted-Average Grant Date Fair Value \| $ / shares	53.63
RSU's cancelled, Weighted-Average Grant Date Fair Value \| $ / shares	26.80
Outstanding at end of period, Weighted-Average Grant Date Fair Value \| $ / shares	$ 25.77

Share-Based Compensation - Summary of Information Regarding Milestone RSU grants and TSR RSU grants (Detail) - Milestone and Total Shareholder Return Restricted Stock Units [Member]	9 Months Ended
	Sep. 30, 2017 $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
RSU's granted, Number of Shares \| shares	454,644
RSU's cancelled, Number of Shares \| shares	(38,838)
Outstanding at end of period, Number of Shares \| shares	415,806
RSU's granted, Weighted-Average Grant Date Fair Value \| $ / shares	$ 15.15
RSU's cancelled, Weighted-Average Grant Date Fair Value \| $ / shares	15.15
Outstanding at end of period, Weighted-Average Grant Date Fair Value \| $ / shares	$ 15.15

Line of Credit - Additional Information (Detail) - USD ($)			3 Months Ended	9 Months Ended
	Oct. 03, 2016	Sep. 30, 2016	Sep. 30, 2016	Sep. 30, 2016
Line of Credit Facility [Line Items]
Interest expense			$ 12,260	$ 12,260
Secured Line of Credit [Member]
Line of Credit Facility [Line Items]
Line of credit maximum amount		$ 150,800,000	150,800,000	150,800,000
Line of credit, collateral amount held by the lender		150,800,000	150,800,000	150,800,000
Line of credit borrowed amount		$ 125,000,000	125,000,000	125,000,000
Repayment of line of credit	$ 125,000,000
Description of variable rate basis		LIBOR plus 2.991%
Interest expense			12,260
Line of credit fair value		$ 125,000,000	$ 125,000,000	$ 125,000,000
Secured Line of Credit [Member] \| London Interbank Offered Rate (LIBOR) [Member]
Line of Credit Facility [Line Items]
Variable interest rate		2.991%

Collaborations and License Agreements - Additional Information (Detail) - Collaborative Arrangement, Product [Member] - Bristol-Myers Squibb Company [Member] - USD ($)		1 Months Ended		9 Months Ended
	May 31, 2005	Dec. 31, 2014	Dec. 31, 2013	Sep. 30, 2017
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Company made an upfront payment	$ 1,000,000
Company made milestone payment		$ 1,500,000	$ 1,250,000
Company remaining milestone payment				$ 12,000,000
Obliged to make milestone payments				$ 14,750,000
License expiration period				Through the later of ten years after first commercial sale of a licensed product in such country, expiration of the last licensed patent covering a licensed product