Catalyst Pharmaceuticals (CPRX) 10-K 15 Mar 17 2016 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2016	Mar. 10, 2017	Jun. 30, 2016
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2016
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	FY
Trading Symbol	CPRX
Entity Registrant Name	CATALYST PHARMACEUTICALS, INC.
Entity Central Index Key	1,369,568
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		82,972,316
Entity Public Float			$ 54,581,032

Balance Sheets

Balance Sheets - USD ($)	Dec. 31, 2016	Dec. 31, 2015
Current Assets:
Cash and cash equivalents	$ 13,893,064	$ 28,235,016
Certificates of deposit		3,717,229
Short-term investments	26,512,753	26,444,150
Prepaid expenses and other current assets	1,047,944	1,504,738
Total current assets	41,453,761	59,901,133
Property and equipment, net	244,204	191,549
Deposits	8,888	8,888
Total assets	41,706,853	60,101,570
Current Liabilities:
Accounts payable	933,176	1,794,127
Accrued expenses and other liabilities	1,161,359	1,646,476
Total current liabilities	2,094,535	3,440,603
Accrued expenses and other liabilities, non-current	181,162	176,293
Warrants liability, at fair value	122,226	1,008,363
Total liabilities	2,397,923	4,625,259
Commitments and contingencies
Stockholders' equity:
Preferred stock, $0.001 par value, 5,000,000 shares authorized: none issued and outstanding at December 31, 2016 and 2015
Common stock, $0.001 par value, 150,000,000 shares authorized; 82,972,316 shares and 82,850,619 shares issued and outstanding at December 31, 2016 and 2015, respectively	82,972	82,851
Additional paid-in capital	147,374,028	145,469,078
Accumulated deficit	(108,148,070)	(90,075,618)
Total stockholders' equity	39,308,930	55,476,311
Total liabilities and stockholders' equity	$ 41,706,853	$ 60,101,570

Balance Sheets (Parenthetical)

Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2016	Dec. 31, 2015
Statement of Financial Position [Abstract]
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	150,000,000	150,000,000
Common stock, shares issued	82,972,316	82,850,619
Common stock, shares outstanding	82,972,316	82,850,619

Statements of Operations

Statements of Operations - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Statement [Abstract]
Revenues	$ 0	$ 0	$ 0
Operating costs and expenses:
Research and development	11,369,941	11,801,342	10,117,774
General and administrative	7,910,260	8,597,010	4,473,654
Total operating costs and expenses	19,280,201	20,398,352	14,591,428
Loss from operations	(19,280,201)	(20,398,352)	(14,591,428)
Other income, net	321,612	100,389	76,233
Change in fair value of warrants liability	886,137	65,005	(993,866)
Loss before income taxes	(18,072,452)	(20,232,958)	(15,509,061)
Provision for income taxes	0	0	0
Net loss	$ (18,072,452)	$ (20,232,958)	$ (15,509,061)
Net loss per share - basic and diluted	$ (0.22)	$ (0.25)	$ (0.24)
Weighted average shares outstanding - basic and diluted	82,875,281	80,858,393	64,142,534

Statement of Stockholders' Equi

Statement of Stockholders' Equity - USD ($)	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Accumulated Deficit [Member]
Beginning Balance at Dec. 31, 2013	$ 21,391,252	$ 54,133	$ 75,670,718	$ (54,333,599)
Issuance of common stock, net	26,725,130	13,024	26,712,106
Issuance of stock options for services	767,838		767,838
Amortization of restricted stock for services	10,131		10,131
Exercise of warrants for common stock	1,335,040	1,262	1,333,778
Exercise of stock options for common stock	522,000	700	521,300
Net loss	(15,509,061)			(15,509,061)
Ending Balance at Dec. 31, 2014	35,242,330	69,119	105,015,871	(69,842,660)
Issuance of common stock, net	34,873,869	11,527	34,862,342
Issuance of stock options for services	1,510,018		1,510,018
Amortization of restricted stock for services	75,440		75,440
Exercise of warrants for common stock	3,617,261	1,178	3,616,083
Exercise of stock options for common stock	390,351	1,027	389,324
Net loss	(20,232,958)			(20,232,958)
Ending Balance at Dec. 31, 2015	55,476,311	82,851	145,469,078	(90,075,618)
Issuance of stock options for services	1,760,591		1,760,591
Amortization of restricted stock for services	75,494		75,494
Exercise of stock options for common stock	68,986	94	68,892
Net loss	(18,072,452)			(18,072,452)
Ending Balance at Dec. 31, 2016	$ 39,308,930	82,972	147,374,028	$ (108,148,070)
Issuance of common stock, net		$ 27	$ (27)

Statements of Cash Flows

Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Operating Activities:
Net loss	$ (18,072,452)	$ (20,232,958)	$ (15,509,061)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	43,406	34,468	26,574
Stock-based compensation	1,836,085	1,585,458	777,969
Change in fair value of warrants liability	(886,137)	(65,005)	993,866
(Increase) decrease in:
Prepaid expenses and other current assets and deposits	456,794	(452,040)	(2,943,256)
Increase (decrease) in:
Accounts payable	(860,951)	(20,083)	963,421
Accrued expenses and other liabilities	(480,248)	1,134,939	2,748,704
Net cash used in operating activities	(17,963,503)	(18,015,221)	(12,941,783)
Investing Activities:
Capital expenditures	(96,061)	(23,465)	(57,323)
Proceeds (purchase) of short-term investments	(68,603)	18,812	(8,979,900)
Proceeds (purchase) of certificates of deposit	3,717,229	(1,846)	296,193
Net cash provided by (used in) investing activities	3,552,565	(6,499)	(8,741,030)
Financing Activities:
Proceeds from issuance of common stock and warrants, net		34,873,869	26,725,130
Payment of employee withholding tax related to stock-based compensation	(11,265)
Proceeds from exercise of warrants		1,895,738	1,316,503
Proceeds from exercise of options	80,251	390,351	522,000
Net cash provided by financing activities	68,986	37,159,958	28,563,633
Net increase (decrease) in cash and cash equivalents	(14,341,952)	19,138,238	6,880,820
Cash and cash equivalents - beginning of period	28,235,016	9,096,778	2,215,958
Cash and cash equivalents - end of period	$ 13,893,064	28,235,016	9,096,778
Non-cash investing and financing activities:
Exercise of liability classified warrants for common stock		1,721,523	$ 18,537
Non-cash incentive received from lessor		$ 131,175

Organization and Description of

Organization and Description of Business	12 Months Ended
	Dec. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Description of Business	1. Organization and Description of Business Catalyst Pharmaceuticals, Inc. (the Company) is a development-stage biopharmaceutical company focused on developing and commercializing innovating therapies for people with rare debilitating diseases, including Lambert-Eaton Myasthenic Syndrome (LEMS), Congenital Myasthenic Syndromes (CMS) and infantile spasms. The Company (f/k/a Catalyst Pharmaceutical Partners, Inc.) was incorporated in Delaware in July 2006. It is the successor by merger to Catalyst Pharmaceutical Partners, Inc., a Florida corporation, which commenced operations in January 2002. Since inception, the Company has devoted substantially all of its efforts to business planning, research and development, recruiting management and technical staff, acquiring operating assets and raising capital. The Company’s primary focus is on the development and commercialization of its drug candidates. The Company has incurred operating losses in each period from inception through December 31, 2016. The Company has been able to fund its cash needs to date through several public and private offerings of its common stock and warrants, through government grants, and through an investment by a strategic purchaser. See Note 11. Capital Resources On January 31, 2014, the Company filed a Shelf Registration Statement on Form S-3 No. 333-193699) On December 23, 2016, the Company filed a Shelf Registration Statement on Form S-3 No. 333-215315) While there can be no assurance, based on currently available information, the Company estimates that it currently has sufficient resources to support its operations for at least the next 12 months. The Company may raise required funds in the future through public or private equity offerings, debt financings, corporate collaborations, governmental research grants or other means. The Company may also seek to raise new capital to fund additional product development efforts, even if it has sufficient funds for its planned operations. Any sale by the Company of additional equity or convertible debt securities could result in dilution to the Company’s current stockholders. There can be no assurance that any such required additional funding will be available to the Company at all or available on terms acceptable to the Company. Further, to the extent that the Company raises additional funds through collaborative arrangements, it may be necessary to relinquish some rights to the Company’s drug candidates or grant sublicenses on terms that are not favorable to the Company. If the Company is not able to secure additional funding when needed, the Company may have to delay, reduce the scope of, or eliminate one or more research and development programs, which could have an adverse effect on the Company’s business.

Basis of Presentation and Signi

Basis of Presentation and Significant Accounting Policies	12 Months Ended
	Dec. 31, 2016
Accounting Policies [Abstract]
Basis of Presentation and Significant Accounting Policies	2. Basis of Presentation and Significant Accounting Policies a. USE OF ESTIMATES. b. CASH AND CASH EQUIVALENTS. c. CERTIFICATES OF DEPOSIT. d. SHORT-TERM INVESTMENTS. e. PREPAID EXPENSES AND OTHER CURRENT ASSETS. pre-commercialization f. PROPERTY AND EQUIPMENT. g. OPERATING LEASES. h. FAIR VALUE OF FINANCIAL INSTRUMENTS. i. FAIR VALUE MEASUREMENTS. Level 1 inputs utilize quoted prices (unadjusted) in active markets for identical assets or liabilities that the Company has the ability to access at the measurement date. Level 2 inputs are inputs other than quoted prices included in Level 1 that are observable for the asset or liability, either directly or indirectly. Level 2 inputs may include quoted prices for similar assets and liabilities in active markets, as well as inputs that are observable for the asset or liability (other than quoted prices), such as interest rates, foreign exchange rates, and yield curves that are observable at commonly quoted intervals. Level 3 inputs are unobservable inputs for the asset or liability, which are typically based on an entity’s own assumptions, as there is little, if any, related market activity. In instances where the determination of the fair value measurement is based on inputs from different levels of the fair value hierarchy, the level in the fair value hierarchy within which the entire fair value measurement falls is based on the lowest level input that is significant to the fair value measurement in its entirety. The Company’s assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment, and considers factors specific to the asset or liability. Fair Value Measurements at Reporting Date Using Balances as of Quoted Prices in Significant Significant Money market funds $ 13,395,759 $ 13,395,759 $ — $ — Short-term investments $ 26,512,753 $ 26,512,753 $ — $ — Warrants liability $ 122,226 $ — $ — $ 122,226 Fair Value Measurements at Reporting Date Using Balances as of Quoted Prices in Significant Significant Money market funds $ 25,157,601 $ 25,157,601 $ — $ — Certificates of deposit $ 3,717,229 $ — $ 3,717,229 $ — Short-term investments $ 26,444,150 $ 26,444,150 $ — $ — Warrants liability $ 1,008,363 $ — $ — $ 1,008,363 j. WARRANTS LIABILITY. k. RESEARCH AND DEVELOPMENT. l. STOCK-BASED COMPENSATION. For the years ended December 31, 2016, 2015 and 2014, the Company recorded stock-based compensation expense as follows: 2016 2015 2014 Research and development $ 590,857 $ 378,548 $ 133,862 General and administrative 1,245,228 1,206,910 644,107 Total stock-based compensation $ 1,836,085 $ 1,585,458 $ 777,969 m. CONCENTRATION OF CREDIT RISK. n. INCOME TAXES. The Company recognizes the financial statement benefit of a tax position only after determining that the relevant tax authority would more likely than not sustain the position following an audit. For tax positions meeting the more-likely-than-not The Company is subject to income taxes in the U.S. federal jurisdiction and various state jurisdictions. Tax regulations within each jurisdiction are subject to the interpretation of the related tax laws and regulations and require significant judgment to apply. The Company is not subject to U.S. federal, state and local tax examinations by tax authorities for years before 2013. If the Company were to subsequently record an unrecognized tax benefit, associated penalties and tax related interest expense would be reported as a component of income tax expense. o. COMPREHENSIVE INCOME (LOSS). p. NET INCOME (LOSS) PER SHARE. 2016 2015 2014 Stock options to purchase common stock 4,660,000 4,250,000 3,884,610 Warrants to purchase common stock 2,407,663 2,407,663 3,585,924 Unvested restricted stock 26,667 53,334 80,000 Potential equivalent common stock excluded 7,094,330 6,710,997 7,550,534 Potentially dilutive stock options to purchase common stock as of both December 31, 2016 and December 31, 2015, have exercise prices ranging from $0.47 to $4.64. Potentially dilutive stock options to purchase common stock as of December 31, 2014, have exercise prices ranging from $0.47 to $3.12. Potentially dilutive warrants to purchase common stock as of December 31, 2016, 2015 and 2014 have exercise prices ranging from $1.04 to $2.08 and expire in periods between May 2017 and August 2017. q. SEGMENT INFORMATION. r. RECLASSIFICATIONS. s. RECENTLY ISSUED ACCOUNTING STANDARDS. No. 2014-15, 205-40): Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) 2016-02 In March, 2016, the FASB issued ASU No. 2016-09, Compensation—Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting

Warrants Liability, at Fair Val

Warrants Liability, at Fair Value	12 Months Ended
	Dec. 31, 2016
Text Block [Abstract]
Warrants Liability, at Fair Value	3. Warrants Liability, at Fair Value The Company allocated approximately $1.3 million of proceeds from its October 2011 registered direct offering to the fair value of common stock purchase warrants issued in connection with the offering that are classified as a liability (the 2011 warrants). The 2011 warrants are classified as a liability because of provisions in such warrants that allow for the net cash settlement of such warrants in the event of certain fundamental transactions (as defined in the warrant agreement). The valuation of the 2011 warrants is determined using the Black-Scholes Model. This model uses inputs such as the underlying price of the shares issued when the warrant is exercised, volatility, risk free interest rate and expected life of the instrument. The Company has determined that the 2011 warrants liability should be classified within Level 3 of the fair value hierarchy by evaluating each input for the Black-Scholes Model against the fair value hierarchy criteria and using the lowest level of input as the basis for the fair value classification. There are six inputs: closing price of the Company’s common stock on the day of evaluation; the exercise price of the warrants; the remaining term of the warrants; the volatility of the Company’s common stock; annual rate of dividends; and the risk-free rate of return. Of those inputs, the exercise price of the warrants and the remaining term are readily observable in the warrants agreement. The annual rate of dividends is based on the Company’s historical practice of not granting dividends. The closing price of the Company’s common stock would fall under Level 1 of the fair value hierarchy as it is a quoted price in an active market. The risk-free rate of return is a Level 2 input, while the historical volatility is a Level 3 input in accordance with the fair value accounting guidance. Since the lowest level input is a Level 3, the Company determined the 2011 warrants liability is most appropriately classified within Level 3 of the fair value hierarchy. This liability is subject to a fair value mark-to-market December 31, 2016 December 31, 2015 Risk free interest rate 0.85 % 0.79 % Expected term 0.33 years 1.34 years Expected volatility 100 % 68 % Expected dividend yield 0 % 0 % Expected forfeiture rate 0 % 0 % The following table rolls forward the fair value of the Company’s warrants liability activity for the years ended December 31, 2016, 2015 and 2014: 2016 2015 2014 Fair value, beginning of period $ 1,008,363 $ 2,794,891 $ 1,819,562 Issuance of warrants — — — Exercise of warrants — (1,721,523 ) (18,537 ) Change in fair value (886,137 ) (65,005 ) 993,866 Fair value, end of period $ 122,226 $ 1,008,363 $ 2,794,891 During 2016, none of the 2011 warrants were exercised. During 2015, 478,261 of the 2011 warrants were exercised, with proceeds to the Company of $621,739. During 2014, 12,696 of the 2011 warrants were exercised, with proceeds to the Company of $16,504. The Company recognizes the change in the fair value of the warrants liability as a non-operating

Prepaid Expenses and Other Curr

Prepaid Expenses and Other Current Assets	12 Months Ended
	Dec. 31, 2016
Text Block [Abstract]
Prepaid Expenses and Other Current Assets	4. Prepaid Expenses and Other Current Assets Prepaid expenses and other current assets consist of the following as of December 31: 2016 2015 Prepaid research fees $ 334,565 $ 915,194 Prepaid insurance 598,909 436,726 Prepaid pre-commercialization 35,500 90,248 Prepaid subscriptions fees 22,770 26,602 Prepaid rent 19,756 1,252 Other 36,444 34,716 Total prepaid expenses and other current assets $ 1,047,944 $ 1,504,738

Property and Equipment

Property and Equipment	12 Months Ended
	Dec. 31, 2016
Property, Plant and Equipment [Abstract]
Property and Equipment	5. Property and Equipment Property and equipment, net consists of the following as of December 31: 2016 2015 Computer equipment $ 27,915 $ 27,915 Furniture and equipment 177,061 102,533 Leasehold improvements 152,708 131,175 357,684 261,623 Less: Accumulated depreciation (113,480 ) (70,074 ) Total property and equipment, net $ 244,204 $ 191,549 Depreciation expense was $43,406, $34,468, and $26,574, respectively, for the years ended December 31, 2016, 2015 and 2014.

Accrued Expenses and Other Liab

Accrued Expenses and Other Liabilities	12 Months Ended
	Dec. 31, 2016
Payables and Accruals [Abstract]
Accrued Expenses and Other Liabilities	6. Accrued Expenses and Other Liabilities Accrued expenses and other liabilities consist of the following as of December 31: 2016 2015 Accrued preclinical and clinical trial expenses $ 623,855 $ 332,905 Accrued professional fees 102,673 330,490 Accrued compensation and benefits 264,237 894,846 Accrued license fees 152,500 52,500 Deferred rent and lease incentive 18,094 18,093 Other — 17,642 Current accrued expenses and other liabilities 1,161,359 1,646,476 Deferred rent and lease incentive—non-current 181,162 176,293 Non-current 181,162 176,293 Total accrued expenses and other liabilities $ 1,342,521 $ 1,822,769

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	7. Commitments and Contingencies The Company has contracted with drug manufacturers and other vendors, including clinical research organizations (CRO) overseeing the clinical trials of the Company’s drug candidates, to assist in the execution of the Company’s preclinical and clinical trials, analysis, and the preparation of material necessary for the submission of new drug applications (NDAs) and abbreviated new drug applications (ANDAs) with the U.S. Food and Drug Administration (FDA). The contracts are cancelable at any time, but obligate the Company to reimburse the providers for any time or costs incurred through the date of termination. The Company has executed a non-cancellable 2017 $ 207,421 2018 213,644 2019 220,053 2020 226,655 2021 233,454 Thereafter 220,023 $ 1,321,250 In March 2015, the Company amended the lease to its corporate offices to obtain additional space for its expanding operations. The Company now leases approximately 5,200 square feet and the lease term now expires on 2022, although the Company has the right to terminate the lease in November 2017 based on the payment of an early termination fee. In connection with the expansion, approximately $131,000 of tenant build-out There are no obligations under capital leases. For commitments related to the Company’s license agreements with BioMarin (defined below) and Northwestern (defined below), see Note 8.

Agreements

Agreements	12 Months Ended
	Dec. 31, 2016
Text Block [Abstract]
Agreements	8. Agreements a. LICENSE AGREEMENT WITH NORTHWESTERN UNIVERSITY. CPP-115. Under the license agreement with Northwestern, the Company is responsible for continued research and development of any resulting product candidates. As of December 31, 2016, the Company has paid $411,590 in connection with the license and has accrued license fees of $152,500 and $52,500 as of December 31, 2016, and 2015, respectively, in the accompanying balance sheets for expenses, maintenance fees and milestones. In addition, the Company is obligated to pay certain milestone payments in future years relating to clinical development activities with respect to CPP-115, CPP-115 b. LICENSE AGREEMENT WITH NEW YORK UNIVERSITY AND THE FEINSTEIN INSTITUTE FOR MEDICAL RESEARCH. c LICENSE AGREEMENT WITH BIOMARIN ® ® ® As part of the License Agreement, the Company agreed: (i) to pay BioMarin royalties for seven years from the first commercial sale of Firdapse ® ® ® ® ® On April 15, 2014, effective as of April 8, 2014, the Company and BioMarin entered into Amendment No. 1 to the License Agreement, amending in certain respects the License Agreement, dated October 26, 2012. The amendment related to purchases of additional product by the Company from BioMarin, the sharing of data between the parties with respect to clinical trials and studies undertaken by each party and the payment terms for certain joint studies. d. AGREEMENTS FOR DRUG DEVELOPMENT, PRECLINICAL AND CLINICAL STUDIES

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2016
Related Party Transactions [Abstract]
Related Party Transactions	9. Related Party Transactions During the years ended December 31, 2016, 2015 and 2014, the Company paid approximately $10,000, $10,000, and $10,000, respectively, in consulting fees to members of the Company’s Scientific Advisory Board. During 2015, the Company entered into a consulting agreement with one of its directors to serve as interim chief commercial officer during the period that the Company sought to fill that position. The consulting arrangement ended in September 2015 and the director received a total of $45,000 in consulting fees for those services. The Company has an employment agreement with its Chief Executive Officer. Under this agreement, the CEO will receive an annual base salary of approximately $485,000 in 2017. This agreement expires in November 2018.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Income Taxes	10. Income Taxes Due to the ongoing operating losses and the inability to recognize any income tax benefit, there is no provision for income taxes in any period presented in these financial statements. Since inception, the Company has only generated pretax losses. The reconciliation of income tax expense (benefit) computed at the statutory federal income tax rate of 34% to amounts included in the statements of operations is as follows: 2016 2015 2014 Statutory rate 34.0 % 34.0 % 34.0 % State tax 3.4 % 3.6 % 3.7 % Valuation allowance (44.7 )% (37.7 )% (35.5 )% Tax credit 6.16 % 0.0 % 0.0 % Other 1.14 % 0.1 % (2.2 )% 0.0 % 0.0 % 0.0 % Deferred tax assets and liabilities reflect the net tax effects of net operating loss and tax credit carryovers and the temporary differences between the carrying amounts of assets and liabilities for financial reporting and the amounts used for income tax purposes. Significant components of the Company’s deferred tax assets as of December 31, 2016 and 2015 are as follows: 2016 2015 Net operating loss $ 21,050,217 $ 18,684,232 Start-up 12,823,113 9,997,709 Tax credits 6,960,838 3,167,766 Deferred compensation 1,555,425 2,368,352 Other 207,133 90,705 Gross deferred tax asset 42,596,726 34,308,764 Valuation allowance (42,596,726 ) (34,308,764 ) Net deferred tax assets $ 0 $ 0 The Company’s deferred tax assets have been fully offset by a valuation allowance at December 31, 2016 and 2015 because the Company believes that it is more likely than not that the deferred tax asset will not be realized. The increase in the valuation allowance on the deferred tax assets was $8,287,962 and $9,413,647 for the years ended December 31, 2016 and 2015, respectively. At December 31, 2016 and 2015, respectively, the Company had net operating loss carryforwards of approximately $56.3 million and $49.9 million available to reduce future taxable income, if any. The net operating loss carryforwards will expire at various dates beginning in 2023 and ending in 2036. If an ownership change, as defined under Internal Revenue Code Section 382, occurs, the use of these carry-forwards may be subject to limitation. The effective tax rate of 0% in all periods presented differs from the statutory rate of 34% due to the valuation allowance and because the Company had no taxable income. Beginning in 2010, the Company has received several orphan drug designations by the FDA for products currently under development. The orphan drug designations allow the Company to claim increased federal tax credits for certain research and development activities. No interest or penalties were accrued through December 31, 2016. The Company’s policy is to recognize any related interest or penalties in income tax expense. The Company is not subject to U.S federal, state and local tax examinations by tax authorities for any years before 2013. The Company is not currently under income tax examinations by any tax authorities.

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2016
Equity [Abstract]
Stockholders' Equity	11. Stockholders’ Equity Preferred Stock The Company has 5,000,000 shares of authorized preferred stock, $0.001 par value per share at December 31, 2016 and 2015. No shares of preferred stock were outstanding at December 31, 2016 and 2015. Common Stock During 2015, the Company’s stockholders approved an increase in the Company’s authorized common stock par value $0.001 per share, from 100,000,000 shares to 150,000,000 shares. At December 31, 2016 and 2015, 82,972,316 and 82,850,619 shares, respectively, of common stock were issued and outstanding. Each holder of common stock is entitled to one vote of each share of common stock held of record on all matters on which stockholders generally are entitled to vote. 2014 Shelf Registration Statement On January 31, 2014, the Company filed a Shelf Registration Statement on Form S-3 No. 333-193699) (a) On April 3, 2014, the Company filed a prospectus supplement and offered for sale 13,023,750 shares of its common stock at a price of $2.21 per share in an underwritten public offering. The Company received gross proceeds in the public offering of approximately $28.8 million before underwriting commission and incurred expenses of approximately $2.1 million. (b) On February 4, 2015, the Company filed a prospectus supplement and offered for sale 11,500,000 shares of its common stock at a price of $3.25 per share in an underwritten public offering. The Company received gross proceeds in the public offering of approximately $37.4 million before underwriting commission and incurred expenses of approximately $2.5 million. As of December 31, 2016, there is approximately $33.8 million available for future sale under the 2014 Shelf Registration Statement. 2016 Shelf Registration Statement On December 23, 2016, the Company filed a Shelf Registration Statement on Form S-3 No. 333-215315) If the Company’s public float (the market value of its common stock held by non-affiliate one-third 12-month Warrant Exercises No warrants were exercised during the year ended December 31, 2016. For the years ended December 31, 2015, and 2014, the Company issued an aggregate of 1,178,261 and 1,262,296 shares of its authorized but unissued common stock upon the exercise of previously issued common stock purchase warrants, raising gross proceeds of $1,895,738 and $1,316,503, respectively. Stockholder Rights Plan On September 20, 2011, the Board of Directors approved the Company’s adoption of a Stockholder Rights Plan. Under the Plan, a dividend of one preferred share purchase right (a Right) was declared for each share of common stock of the Company that was outstanding on October 7, 2011. Each Right entitles the holder to purchase from the Company one one-hundredth The Rights trade automatically with the common stock and will not be exercisable until a person or group has become an “acquiring person” by acquiring 17.5% or more of the Company’s outstanding common stock, or a person or group commences, or publicly announces a tender offer that will result in such a person or group owning 17.5% or more of the Company’s outstanding common stock. Upon announcement that any person or group has become an acquiring person, each Right will entitle all rightholders (other than the acquiring person) to purchase, for the exercise price of $7.80, a number of shares of the Company’s common stock having a market value equal to twice the exercise price. Rightholders would also be entitled to purchase common stock of the acquiring person having a value of twice the exercise price if, after a person had become an acquiring person, the Company were to enter into certain mergers or other transactions. If any person becomes an acquiring person, the Board of Directors may, at its option and subject to certain limitations, exchange one share of common stock for each Right. The Rights have certain anti-takeover effects, in that they would cause substantial dilution to a person or group that attempts to acquire a significant interest in the Company on terms not approved by the Board of Directors. In the event that the Board of Directors determines a transaction to be in the best interests of the Company and its stockholders, the Board of Directors may redeem the Rights for $0.001 per share at any time prior to a person or group becoming an acquiring person. On September 19, 2016, the Board of Directors unanimously approved, and on the same date the Company entered into Amendment No. 1 to the Stockholders Rights Plan (the “Amendment”). Under the terms of the Amendment, the outside expiration date of the rights plan has been extended from September 20, 2016 to September 20, 2019. Additionally, as part of the Amendment, the Board adopted a Certificate of Designation, Preferences and Rights of Series A Junior Participating Preferred Stock of the Company to increase the number of shares of Series A Junior Participating Preferred Stock of the Company available for issuance under the Rights Plan from 500,000 shares to 1.5 million shares.

Stock Compensation Plans

Stock Compensation Plans	12 Months Ended
	Dec. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock Compensation Plans	12. Stock Compensation Plans Stock Options The Company may issue stock options, restricted stock, stock appreciation rights and restricted stock units (collectively, the “Awards”) to employees, directors, consultants and scientific advisors of the Company under the 2006 and 2014 Stock Incentive Plans (the 2006 Plan and the 2014 Plan or collectively, the Plans). At December 31, 2016, no shares remain available for future issuance under the 2006 Plan. Under the 2014 Plan, 6,000,000 shares were reserved for issuance and as of December 31, 2016, 2,076,667 shares remain available for future issuance. The Company has granted stock options to employees, officers, directors, scientific advisors and consultants generally at exercise prices equal to the market price of the common stock at grant date. Option awards generally vest over a period of 1 to 3 years of continuous service and have contractual terms from 5 to 7 years. Certain awards provide for accelerated vesting if there is a change in control. The Company issues new shares as shares are required to be delivered upon exercise of outstanding stock options. During the years ended December 31, 2016, 2015, and 2014, options to purchase 75,000, 265,000, and 580,000 shares of the Company’s common stock were exercised with gross proceeds to the Company of $80,251, $390,351, and $522,000, respectively. Further, during the years ended December 31, 2016, 2015, and 2014, options to purchase 50,000, 984,608, and 185,000 shares of the Company’s common stock were exercised on a “cashless” basis, resulting in the issuance of an aggregate of 20,030, 761,600, and 119,709 shares of the Company’s common stock, respectively. During the years ended December 31, 2016, 2015 and 2014 the Company recorded non-cash During the years ended December 31, 2016 and 2015, the Company granted seven-year options to purchase an aggregate of 1,285,000 and 1,760,000 shares, respectively, of the Company’s common stock to certain of the Company’s officers, employees, directors, and consultants. During the year ended December 31, 2014, the Company granted five and seven-year options to purchase an aggregate of 1,305,000 shares of the Company’s common stock to certain of the Company’s officers, employees, directors and consultants. Stock option activity under the Company’s Plans for the year ended December 31, 2016 is summarized as follows: Number of Weighted Weighted Aggregate Outstanding at beginning of year 4,250,000 $ 2.23 Granted 1,285,000 0.94 Exercised (125,000 ) 0.83 Forfeited or cancelled (360,000 ) 3.06 Expired (390,000 ) 1.07 Outstanding at end of year 4,660,000 $ 1.94 4.66 $ 805,900 Exercisable at end of year 2,386,663 $ 2.02 3.44 $ 515,500 Other information pertaining to stock option activity during the years ended December 31, 2016, 2015 and 2014 was as follows: 2016 2015 2014 Weighted–average fair value of granted stock options $ 0.62 $ 2.13 $ 2.41 Total fair value of vested stock options $ 1,634,562 $ 1,307,895 $ 409,476 Total intrinsic value of exercised stock options $ 42,000 $ 3,311,599 $ 1,339,100 The following table summarizes information about the Company’s options outstanding at December 31, 2016: Options Outstanding Options Exercisable Range of Number Weighted Weighted Number Weighted Weighted $0.47 to $0.63 900,000 0.95 $ 0.47 875,000 0.95 $ 0.47 $0.64 to $0.82 1,060,000 6.45 $ 0.79 — — — $0.83 to $2.67 1,260,000 5.65 $ 2.38 603,333 5.25 $ 2.41 $2.68 to $3.23 1,035,000 4.67 $ 3.11 751,665 4.67 $ 3.11 $3.24 to $4.64 405,000 5.03 $ 3.87 156,665 4.43 $ 3.94 4,660,000 4.66 $ 1.94 2,386,663 3.44 $ 2.02 As of December 31, 2016, there was approximately $2,320,289 of unrecognized compensation expense related to non-vested The Company utilizes the Black-Scholes option-pricing model to determine the fair value of stock options on the date of grant. This model derives the fair value of stock options based on certain assumptions related to the expected stock price volatility, expected option life, risk-free interest rate and dividend yield. Expected volatility is based on reviews of historical volatility of the Company’s common stock. The estimated expected option life is based upon estimated employee exercise patterns and considers whether and the extent to which the options are in-the-money. mid-point Assumptions used during the years were as follows: Year ended December 31, 2016 2015 2014 Risk free interest rate 0.76% to 2.15 % 1.00% to 2.13 % 1.18% to 2.03 % Expected term 2 to 6 years 3 to 7 years 3 to 7 years Expected volatility 100 % 102 % 115 % Expected dividend yield — % — % — % Expected forfeiture rate — % — % — % Restricted Stock Units Under the 2014 Plan, participants may be granted restricted stock units, each of which represents a conditional right to receive shares of common stock in the future. The restricted stock units granted under this plan generally vest ratably over a three to four-year period. Upon vesting, the restricted stock units will convert into an equivalent number of shares of common stock. The amount of expense relating to the restricted stock units is based on the closing market price of the Company’s common stock on the date of grant and is amortized on a straight-line basis over the requisite service period. Restricted stock unit activity during 2016, 2015, and 2014 was as follows: 2016 2015 2014 Number of Weighted Number of Weighted Number of Weighted Nonvested balance at beginning of year 53,334 $ 2.83 80,000 $ 2.83 — $ — Granted — — — — 80,000 — Vested (26,667 ) 2.83 (26,666 ) 2.83 — 2.83 Forfeited — — — — — — Nonvested balance at end of year 26,667 $ 2.83 53,334 $ 2.83 80,000 $ 2.83 During the years ended December 31, 2016, 2015 and 2014, the Company recorded non-cash

Benefit Plan

Benefit Plan	12 Months Ended
	Dec. 31, 2016
Compensation and Retirement Disclosure [Abstract]
Benefit Plan	13. Benefit Plan The Company maintains an employee savings plan pursuant to Section 401(k) of the Internal Revenue Code covering all eligible employees. Subject to certain dollar limits, eligible employees may contribute up to 15% of their pre-tax

Quarterly Financial Information

Quarterly Financial Information (unaudited)	12 Months Ended
	Dec. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Information (unaudited)	14. Quarterly Financial Information (unaudited) The following table presents unaudited supplemental quarterly financial information for the years ended December 31, 2016 and 2015: Quarter Ended March 31, 2016 June 30, 2016 September 30, December 31, Revenues $ — $ — $ — $ — Loss from operations (6,237,536 ) (4,814,452 ) (3,914,014 ) (4,314,199 ) Change in fair value of warrants liability 733,356 152,783 (106,948 ) 106,946 Net loss $ (5,386,237 ) $ (4,568,914 ) $ (3,953,981 ) $ (4,163,320 ) Loss per share—basic and diluted $ (0.07 ) $ (0.06 ) $ (0.05 ) $ (0.05 ) Quarter Ended March 31, June 30, 2015 September 30, December 31, Revenues $ — $ — $ — $ — Loss from operations (4,291,915 ) (4,897,330 ) (5,017,428 ) (6,191,679 ) Change in fair value of warrants liability (1,180,278 ) 333,956 521,731 389,596 Net loss $ (5,410,259 ) $ (4,558,503 ) $ (4,449,038 ) $ (5,815,158 ) Loss per share—basic and diluted $ (0.07 ) $ (0.06 ) $ (0.05 ) $ (0.07 ) Quarterly basic and diluted net loss per common share were computed independently for each quarter and do not necessarily total to the full year basic and diluted net loss per common share.

Basis of Presentation and Sig21

Basis of Presentation and Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2016
Accounting Policies [Abstract]
USE OF ESTIMATES	a. USE OF ESTIMATES.
CASH AND CASH EQUIVALENTS	b. CASH AND CASH EQUIVALENTS.
CERTIFICATES OF DEPOSIT	c. CERTIFICATES OF DEPOSIT.
SHORT-TERM INVESTMENTS	d. SHORT-TERM INVESTMENTS.
PREPAID EXPENSES AND OTHER CURRENT ASSETS	e. PREPAID EXPENSES AND OTHER CURRENT ASSETS. pre-commercialization
PROPERTY AND EQUIPMENT	f. PROPERTY AND EQUIPMENT.
OPERATING LEASES	g. OPERATING LEASES.
FAIR VALUE OF FINANCIAL INSTRUMENTS	h. FAIR VALUE OF FINANCIAL INSTRUMENTS.
FAIR VALUE MEASUREMENTS	i. FAIR VALUE MEASUREMENTS. Level 1 inputs utilize quoted prices (unadjusted) in active markets for identical assets or liabilities that the Company has the ability to access at the measurement date. Level 2 inputs are inputs other than quoted prices included in Level 1 that are observable for the asset or liability, either directly or indirectly. Level 2 inputs may include quoted prices for similar assets and liabilities in active markets, as well as inputs that are observable for the asset or liability (other than quoted prices), such as interest rates, foreign exchange rates, and yield curves that are observable at commonly quoted intervals. Level 3 inputs are unobservable inputs for the asset or liability, which are typically based on an entity’s own assumptions, as there is little, if any, related market activity. In instances where the determination of the fair value measurement is based on inputs from different levels of the fair value hierarchy, the level in the fair value hierarchy within which the entire fair value measurement falls is based on the lowest level input that is significant to the fair value measurement in its entirety. The Company’s assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment, and considers factors specific to the asset or liability. Fair Value Measurements at Reporting Date Using Balances as of Quoted Prices in Significant Significant Money market funds $ 13,395,759 $ 13,395,759 $ — $ — Short-term investments $ 26,512,753 $ 26,512,753 $ — $ — Warrants liability $ 122,226 $ — $ — $ 122,226 Fair Value Measurements at Reporting Date Using Balances as of Quoted Prices in Significant Significant Money market funds $ 25,157,601 $ 25,157,601 $ — $ — Certificates of deposit $ 3,717,229 $ — $ 3,717,229 $ — Short-term investments $ 26,444,150 $ 26,444,150 $ — $ — Warrants liability $ 1,008,363 $ — $ — $ 1,008,363
WARRANTS LIABILITY	j. WARRANTS LIABILITY.
RESEARCH AND DEVELOPMENT	k. RESEARCH AND DEVELOPMENT.
STOCK-BASED COMPENSATION	l. STOCK-BASED COMPENSATION. For the years ended December 31, 2016, 2015 and 2014, the Company recorded stock-based compensation expense as follows: 2016 2015 2014 Research and development $ 590,857 $ 378,548 $ 133,862 General and administrative 1,245,228 1,206,910 644,107 Total stock-based compensation $ 1,836,085 $ 1,585,458 $ 777,969
CONCENTRATION OF CREDIT RISK	m. CONCENTRATION OF CREDIT RISK.
INCOME TAXES	n. INCOME TAXES. The Company recognizes the financial statement benefit of a tax position only after determining that the relevant tax authority would more likely than not sustain the position following an audit. For tax positions meeting the more-likely-than-not The Company is subject to income taxes in the U.S. federal jurisdiction and various state jurisdictions. Tax regulations within each jurisdiction are subject to the interpretation of the related tax laws and regulations and require significant judgment to apply. The Company is not subject to U.S. federal, state and local tax examinations by tax authorities for years before 2013. If the Company were to subsequently record an unrecognized tax benefit, associated penalties and tax related interest expense would be reported as a component of income tax expense.
COMPREHENSIVE INCOME (LOSS)	o. COMPREHENSIVE INCOME (LOSS).
NET INCOME (LOSS) PER SHARE	p. NET INCOME (LOSS) PER SHARE. 2016 2015 2014 Stock options to purchase common stock 4,660,000 4,250,000 3,884,610 Warrants to purchase common stock 2,407,663 2,407,663 3,585,924 Unvested restricted stock 26,667 53,334 80,000 Potential equivalent common stock excluded 7,094,330 6,710,997 7,550,534 Potentially dilutive stock options to purchase common stock as of both December 31, 2016 and December 31, 2015, have exercise prices ranging from $0.47 to $4.64. Potentially dilutive stock options to purchase common stock as of December 31, 2014, have exercise prices ranging from $0.47 to $3.12. Potentially dilutive warrants to purchase common stock as of December 31, 2016, 2015 and 2014 have exercise prices ranging from $1.04 to $2.08 and expire in periods between May 2017 and August 2017.
SEGMENT INFORMATION	q. SEGMENT INFORMATION.
RECLASSIFICATIONS	r. RECLASSIFICATIONS.
RECENTLY ISSUED ACCOUNTING STANDARDS	s. RECENTLY ISSUED ACCOUNTING STANDARDS. No. 2014-15, 205-40): Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) 2016-02 In March, 2016, the FASB issued ASU No. 2016-09, Compensation—Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting

Basis of Presentation and Sig22

Basis of Presentation and Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2016
Accounting Policies [Abstract]
Fair Value Measurement Specific to Assets or Liability	The Company’s assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment, and considers factors specific to the asset or liability. Fair Value Measurements at Reporting Date Using Balances as of Quoted Prices in Significant Significant Money market funds $ 13,395,759 $ 13,395,759 $ — $ — Short-term investments $ 26,512,753 $ 26,512,753 $ — $ — Warrants liability $ 122,226 $ — $ — $ 122,226 Fair Value Measurements at Reporting Date Using Balances as of Quoted Prices in Significant Significant Money market funds $ 25,157,601 $ 25,157,601 $ — $ — Certificates of deposit $ 3,717,229 $ — $ 3,717,229 $ — Short-term investments $ 26,444,150 $ 26,444,150 $ — $ — Warrants liability $ 1,008,363 $ — $ — $ 1,008,363
Stock-Based Compensation Expense	For the years ended December 31, 2016, 2015 and 2014, the Company recorded stock-based compensation expense as follows: 2016 2015 2014 Research and development $ 590,857 $ 378,548 $ 133,862 General and administrative 1,245,228 1,206,910 644,107 Total stock-based compensation $ 1,836,085 $ 1,585,458 $ 777,969
Potential Shares Excluded from Determination of Basic and Diluted Net Loss Per Share	p. NET INCOME (LOSS) PER SHARE. 2016 2015 2014 Stock options to purchase common stock 4,660,000 4,250,000 3,884,610 Warrants to purchase common stock 2,407,663 2,407,663 3,585,924 Unvested restricted stock 26,667 53,334 80,000 Potential equivalent common stock excluded 7,094,330 6,710,997 7,550,534

Warrants Liability, at Fair V23

Warrants Liability, at Fair Value (Tables)	12 Months Ended
	Dec. 31, 2016
Summary of Company's Warrants Liability Activity	The following table rolls forward the fair value of the Company’s warrants liability activity for the years ended December 31, 2016, 2015 and 2014: 2016 2015 2014 Fair value, beginning of period $ 1,008,363 $ 2,794,891 $ 1,819,562 Issuance of warrants — — — Exercise of warrants — (1,721,523 ) (18,537 ) Change in fair value (886,137 ) (65,005 ) 993,866 Fair value, end of period $ 122,226 $ 1,008,363 $ 2,794,891
Warrants Liability, at Fair Value [Member]
Summary of Assumptions Used in Black-Scholes Model to Calculate Fair Value of Warrants Liability	The calculated value of the 2011 warrants liability was determined using the Black-Scholes option-pricing model with the following assumptions: December 31, 2016 December 31, 2015 Risk free interest rate 0.85 % 0.79 % Expected term 0.33 years 1.34 years Expected volatility 100 % 68 % Expected dividend yield 0 % 0 % Expected forfeiture rate 0 % 0 %

Prepaid Expenses and Other Cu24

Prepaid Expenses and Other Current Assets (Tables)	12 Months Ended
	Dec. 31, 2016
Text Block [Abstract]
Prepaid Expenses and Other Current Assets	Prepaid expenses and other current assets consist of the following as of December 31: 2016 2015 Prepaid research fees $ 334,565 $ 915,194 Prepaid insurance 598,909 436,726 Prepaid pre-commercialization 35,500 90,248 Prepaid subscriptions fees 22,770 26,602 Prepaid rent 19,756 1,252 Other 36,444 34,716 Total prepaid expenses and other current assets $ 1,047,944 $ 1,504,738

Property and Equipment (Tables)

Property and Equipment (Tables)	12 Months Ended
	Dec. 31, 2016
Property, Plant and Equipment [Abstract]
Property and Equipment, Net	Property and equipment, net consists of the following as of December 31: 2016 2015 Computer equipment $ 27,915 $ 27,915 Furniture and equipment 177,061 102,533 Leasehold improvements 152,708 131,175 357,684 261,623 Less: Accumulated depreciation (113,480 ) (70,074 ) Total property and equipment, net $ 244,204 $ 191,549

Accrued Expenses and Other Li26

Accrued Expenses and Other Liabilities (Tables)	12 Months Ended
	Dec. 31, 2016
Payables and Accruals [Abstract]
Schedule of Accrued Expenses and Other Liabilities	Accrued expenses and other liabilities consist of the following as of December 31: 2016 2015 Accrued preclinical and clinical trial expenses $ 623,855 $ 332,905 Accrued professional fees 102,673 330,490 Accrued compensation and benefits 264,237 894,846 Accrued license fees 152,500 52,500 Deferred rent and lease incentive 18,094 18,093 Other — 17,642 Current accrued expenses and other liabilities 1,161,359 1,646,476 Deferred rent and lease incentive—non-current 181,162 176,293 Non-current 181,162 176,293 Total accrued expenses and other liabilities $ 1,342,521 $ 1,822,769

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Future Minimum Lease Payments under Operating Lease Agreement	As of December 31, 2016, future minimum lease payments under the operating lease agreement are as follows: 2017 $ 207,421 2018 213,644 2019 220,053 2020 226,655 2021 233,454 Thereafter 220,023 $ 1,321,250

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Reconciliation of Income Tax Expense (Benefit) Computed at Statutory Federal Income Tax Rate	The reconciliation of income tax expense (benefit) computed at the statutory federal income tax rate of 34% to amounts included in the statements of operations is as follows: 2016 2015 2014 Statutory rate 34.0 % 34.0 % 34.0 % State tax 3.4 % 3.6 % 3.7 % Valuation allowance (44.7 )% (37.7 )% (35.5 )% Tax credit 6.16 % 0.0 % 0.0 % Other 1.14 % 0.1 % (2.2 )% 0.0 % 0.0 % 0.0 %
Components of Deferred Tax Assets	Significant components of the Company’s deferred tax assets as of December 31, 2016 and 2015 are as follows: 2016 2015 Net operating loss $ 21,050,217 $ 18,684,232 Start-up 12,823,113 9,997,709 Tax credits 6,960,838 3,167,766 Deferred compensation 1,555,425 2,368,352 Other 207,133 90,705 Gross deferred tax asset 42,596,726 34,308,764 Valuation allowance (42,596,726 ) (34,308,764 ) Net deferred tax assets $ 0 $ 0

Stock Compensation Plans (Table

Stock Compensation Plans (Tables)	12 Months Ended
	Dec. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock option activity under the Company's Plans	Stock option activity under the Company’s Plans for the year ended December 31, 2016 is summarized as follows: Number of Weighted Weighted Aggregate Outstanding at beginning of year 4,250,000 $ 2.23 Granted 1,285,000 0.94 Exercised (125,000 ) 0.83 Forfeited or cancelled (360,000 ) 3.06 Expired (390,000 ) 1.07 Outstanding at end of year 4,660,000 $ 1.94 4.66 $ 805,900 Exercisable at end of year 2,386,663 $ 2.02 3.44 $ 515,500
Schedule of Other Information Pertaining to Stock Option Activity	Other information pertaining to stock option activity during the years ended December 31, 2016, 2015 and 2014 was as follows: 2016 2015 2014 Weighted–average fair value of granted stock options $ 0.62 $ 2.13 $ 2.41 Total fair value of vested stock options $ 1,634,562 $ 1,307,895 $ 409,476 Total intrinsic value of exercised stock options $ 42,000 $ 3,311,599 $ 1,339,100
Summary of Company's Stock Options Outstanding	The following table summarizes information about the Company’s options outstanding at December 31, 2016: Options Outstanding Options Exercisable Range of Number Weighted Weighted Number Weighted Weighted $0.47 to $0.63 900,000 0.95 $ 0.47 875,000 0.95 $ 0.47 $0.64 to $0.82 1,060,000 6.45 $ 0.79 — — — $0.83 to $2.67 1,260,000 5.65 $ 2.38 603,333 5.25 $ 2.41 $2.68 to $3.23 1,035,000 4.67 $ 3.11 751,665 4.67 $ 3.11 $3.24 to $4.64 405,000 5.03 $ 3.87 156,665 4.43 $ 3.94 4,660,000 4.66 $ 1.94 2,386,663 3.44 $ 2.02
Summary of Stock Options Awards Based on Certain Assumptions	Assumptions used during the years were as follows: Year ended December 31, 2016 2015 2014 Risk free interest rate 0.76% to 2.15 % 1.00% to 2.13 % 1.18% to 2.03 % Expected term 2 to 6 years 3 to 7 years 3 to 7 years Expected volatility 100 % 102 % 115 % Expected dividend yield — % — % — % Expected forfeiture rate — % — % — %
Summary of Restricted Stock Unit Activity	Restricted stock unit activity during 2016, 2015, and 2014 was as follows: 2016 2015 2014 Number of Weighted Number of Weighted Number of Weighted Nonvested balance at beginning of year 53,334 $ 2.83 80,000 $ 2.83 — $ — Granted — — — — 80,000 — Vested (26,667 ) 2.83 (26,666 ) 2.83 — 2.83 Forfeited — — — — — — Nonvested balance at end of year 26,667 $ 2.83 53,334 $ 2.83 80,000 $ 2.83

Quarterly Financial Informati30

Quarterly Financial Information (unaudited) (Tables)	12 Months Ended
	Dec. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
Schedule of Quarterly Financial Information	The following table presents unaudited supplemental quarterly financial information for the years ended December 31, 2016 and 2015: Quarter Ended March 31, 2016 June 30, 2016 September 30, December 31, Revenues $ — $ — $ — $ — Loss from operations (6,237,536 ) (4,814,452 ) (3,914,014 ) (4,314,199 ) Change in fair value of warrants liability 733,356 152,783 (106,948 ) 106,946 Net loss $ (5,386,237 ) $ (4,568,914 ) $ (3,953,981 ) $ (4,163,320 ) Loss per share—basic and diluted $ (0.07 ) $ (0.06 ) $ (0.05 ) $ (0.05 ) Quarter Ended March 31, June 30, 2015 September 30, December 31, Revenues $ — $ — $ — $ — Loss from operations (4,291,915 ) (4,897,330 ) (5,017,428 ) (6,191,679 ) Change in fair value of warrants liability (1,180,278 ) 333,956 521,731 389,596 Net loss $ (5,410,259 ) $ (4,558,503 ) $ (4,449,038 ) $ (5,815,158 ) Loss per share—basic and diluted $ (0.07 ) $ (0.06 ) $ (0.05 ) $ (0.07 )

Organization and Description 31

Organization and Description of Business - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2016USD ($)Offerings	Dec. 23, 2016USD ($)	Jan. 31, 2014USD ($)
Organization And Description Of Business [Line Items]
Maximum dollar amount of common stock to be issued under shelf registration statement			$ 100,000,000
Number of direct offering under 2014 shelf registration | Offerings	2
Maximum dollar amount of common stock to be issued under shelf registration statement		$ 33,800,000
2014 Shelf Registration Statement [Member]
Organization And Description Of Business [Line Items]
Maximum dollar amount of common stock to be issued under shelf registration statement			$ 100,000,000
Value of common stock available for future sale	$ 33,800,000
Expiry date of common stock remaining under the shelf registration statement	Mar. 19, 2017

Basis of Presentation and Sig32

Basis of Presentation and Significant Accounting Policies - Additional Information (Detail)	1 Months Ended	12 Months Ended
	Oct. 31, 2011shares	Dec. 31, 2016USD ($)Segment$ / sharesshares	Dec. 31, 2015USD ($)$ / sharesshares	Dec. 31, 2014USD ($)$ / shares
Summary Of Basis Of Presentation And Significant Accounting Policies [Line Items]
Maximum maturity period of cash and cash equivalent		Three months
Deferred rent and lease incentive in accrued expenses and other liabilities | $		$ 199,256	$ 194,386
Stock option exercise price range, Minimum		$ 0.47	$ 0.47	$ 0.47
Stock option exercise price range, Maximum		$ 4.64	$ 4.64	$ 3.12
Number of reportable segment | Segment		1
Trading Securities [Member] | Other Income, Net [Member]
Summary Of Basis Of Presentation And Significant Accounting Policies [Line Items]
Unrealized gain (loss) | $		$ 58,861	$ (29,430)	$ (18,316)
October 28, 2011 Warrants [Member]
Summary Of Basis Of Presentation And Significant Accounting Policies [Line Items]
Warrants issued in offering | shares	1,523,370
Warrants outstanding | shares		763,913	763,913
October 28, 2011 Warrants [Member] | Warrants Liability, at Fair Value [Member]
Summary Of Basis Of Presentation And Significant Accounting Policies [Line Items]
Warrants Expiration Date		May 2, 2017
Computer Equipment [Member]
Summary Of Basis Of Presentation And Significant Accounting Policies [Line Items]
Useful life of assets		3 years
Minimum [Member]
Summary Of Basis Of Presentation And Significant Accounting Policies [Line Items]
Maturity period of certificates of deposit		3 months
Minimum amortization period of compensation cost on straight line basis		1 year
Potentially dilutive warrants to purchase common stock		$ 1.04	$ 1.04	$ 1.04
Minimum [Member] | Leasehold Improvements [Member]
Summary Of Basis Of Presentation And Significant Accounting Policies [Line Items]
Useful life of assets		5 years
Minimum [Member] | Furniture and Equipment [Member]
Summary Of Basis Of Presentation And Significant Accounting Policies [Line Items]
Useful life of assets		3 years
Maximum [Member]
Summary Of Basis Of Presentation And Significant Accounting Policies [Line Items]
Maturity period of certificates of deposit			1 year
Minimum amortization period of compensation cost on straight line basis		3 years
Potentially dilutive warrants to purchase common stock		$ 2.08	$ 2.08	$ 2.08
Maximum [Member] | Leasehold Improvements [Member]
Summary Of Basis Of Presentation And Significant Accounting Policies [Line Items]
Useful life of assets		7 years
Maximum [Member] | Furniture and Equipment [Member]
Summary Of Basis Of Presentation And Significant Accounting Policies [Line Items]
Useful life of assets		6 years

Basis of Presentation and Sig33

Basis of Presentation and Significant Accounting Policies - Fair Value Measurement Specific to Assets or Liability (Detail) - USD ($)	Dec. 31, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Certificates of deposit		$ 3,717,229
Short-term investments	$ 26,512,753	26,444,150
Warrants liability	122,226	1,008,363
Money Market Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market funds	13,395,759	25,157,601
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	26,512,753	26,444,150
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Money Market Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market funds	13,395,759	25,157,601
Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Certificates of deposit		3,717,229
Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Warrants liability	$ 122,226	$ 1,008,363

Basis of Presentation and Sig34

Basis of Presentation and Significant Accounting Policies - Stock-Based Compensation Expense (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation	$ 1,836,085	$ 1,585,458	$ 777,969
Research and Development [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation	590,857	378,548	133,862
General and Administrative [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation	$ 1,245,228	$ 1,206,910	$ 644,107

Basis of Presentation and Sig35

Basis of Presentation and Significant Accounting Policies - Potential Shares Excluded from Determination of Basic and Diluted Net Loss Per Share (Detail) - shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential equivalent common stock excluded	7,094,330	6,710,997	7,550,534
Options to Purchase Common Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential equivalent common stock excluded	4,660,000	4,250,000	3,884,610
Warrants Liability, at Fair Value [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential equivalent common stock excluded	2,407,663	2,407,663	3,585,924
Unvested Restricted Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential equivalent common stock excluded	26,667	53,334	80,000

Warrants Liability, at Fair V36

Warrants Liability, at Fair Value - Additional Information (Detail) - USD ($)	1 Months Ended	12 Months Ended
	Oct. 31, 2011	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Class of Warrant or Right [Line Items]
Recognition of warrants fair value at date of issuance		$ 0	$ 0	$ 0
Number of warrants exercised during the period		0	1,178,261	1,262,296
Proceeds from exercise of warrants			$ 1,895,738	$ 1,316,503
October 28, 2011 Warrants [Member] | Warrants Liability, at Fair Value [Member]
Class of Warrant or Right [Line Items]
Recognition of warrants fair value at date of issuance	$ 1,300,000
Number of warrants exercised during the period		0	478,261	12,696
Proceeds from exercise of warrants			$ 621,739	$ 16,504

Warrants Liability, at Fair V37

Warrants Liability, at Fair Value - Summary of Assumptions Used in Black-Scholes Model to Calculate Fair Value of Warrants Liability (Detail) - Warrants Liability, at Fair Value [Member]	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Risk free interest rate	0.85%	0.79%
Expected term	3 months 29 days	1 year 4 months 2 days
Expected volatility	100.00%	68.00%
Expected dividend yield	0.00%	0.00%
Expected forfeiture rate	0.00%	0.00%

Warrants Liability, at Fair V38

Warrants Liability, at Fair Value - Summary of Company's Warrants Liability Activity (Detail) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Fair value, beginning of period				$ 1,008,363				$ 2,794,891	$ 1,008,363	$ 2,794,891	$ 1,819,562
Issuance of warrants									0	0	0
Exercise of warrants										(1,721,523)	(18,537)
Change in fair value	$ (106,946)	$ 106,948	$ (152,783)	$ (733,356)	$ (389,596)	$ (521,731)	$ (333,956)	$ 1,180,278	(886,137)	(65,005)	993,866
Fair value, end of period	$ 122,226				$ 1,008,363				$ 122,226	$ 1,008,363	$ 2,794,891

Prepaid Expenses and Other Cu39

Prepaid Expenses and Other Current Assets - Prepaid Expenses and Other Current Assets (Detail) - USD ($)	Dec. 31, 2016	Dec. 31, 2015
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Prepaid research fees	$ 334,565	$ 915,194
Prepaid insurance	598,909	436,726
Prepaid pre-commercialization fees	35,500	90,248
Prepaid subscriptions fees	22,770	26,602
Prepaid rent	19,756	1,252
Other	36,444	34,716
Total prepaid expenses and other current assets	$ 1,047,944	$ 1,504,738

Property and Equipment - Proper

Property and Equipment - Property and Equipment, Net (Detail) - USD ($)	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 357,684	$ 261,623
Less: Accumulated depreciation	(113,480)	(70,074)
Total property and equipment, net	244,204	191,549
Computer Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	27,915	27,915
Furniture and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	177,061	102,533
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 152,708	$ 131,175

Property and Equipment - Additi

Property and Equipment - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment [Abstract]
Depreciation expenses	$ 43,406	$ 34,468	$ 26,574

Accrued Expenses and Other Li42

Accrued Expenses and Other Liabilities - Schedule of Accrued Expenses and Other Liabilities (Detail) - USD ($)	Dec. 31, 2016	Dec. 31, 2015
Payables and Accruals [Abstract]
Accrued preclinical and clinical trial expenses	$ 623,855	$ 332,905
Accrued professional fees	102,673	330,490
Accrued compensation and benefits	264,237	894,846
Accrued license fees	152,500	52,500
Deferred rent and lease incentive	18,094	18,093
Other		17,642
Current accrued expenses and other liabilities	1,161,359	1,646,476
Deferred rent and lease incentive-non-current	181,162	176,293
Non-current accrued expenses and other liabilities	181,162	176,293
Total accrued expenses and other liabilities	$ 1,342,521	$ 1,822,769

Commitments and Contingencies -

Commitments and Contingencies - Future Minimum Lease Payments under Operating Lease Agreement (Detail)	Dec. 31, 2016USD ($)
Commitments and Contingencies Disclosure [Abstract]
2,017	$ 207,421
2,018	213,644
2,019	220,053
2,020	226,655
2,021	233,454
Thereafter	220,023
Total	$ 1,321,250

Commitments and Contingencies44

Commitments and Contingencies - Additional Information (Detail)	1 Months Ended	12 Months Ended
	Mar. 31, 2015USD ($)ft²	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)
Commitments and Contingencies Disclosure [Abstract]
Area of leased property | ft²	5,200
Lease expiration year	2,022
Right to terminate lease date	2017-11
Tenant build-out costs	$ 131,000
Rent expense		$ 201,920	$ 129,727	$ 90,163
Obligations under capital leases		$ 0

Agreements - Northwestern Unive

Agreements - Northwestern University - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
License Agreement [Line Items]
Accrued license fees	$ 152,500	$ 52,500
Northwestern License Agreement [Member]
License Agreement [Line Items]
License fee paid	411,590
Accrued license fees	152,500	$ 52,500
Future milestone payment	$ 300,000

Agreements - BioMarin - Additio

Agreements - BioMarin - Additional Information (Detail) - License Agreement with BioMarin [Member] - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Oct. 26, 2012
License Agreement [Line Items]
Date on which strategic collaboration is entered into	Oct. 26, 2012
Investment pursuant to strategic collaboration			$ 5,000,000
Royalty agreement period	7 years
Net sales royalty threshold	$ 100,000,000
Milestone payment due upon NDA acceptance	2,600,000
Milestone payment due upon NDA approval	7,200,000
Costs paid for Firdapse joint studies	$ 3,800,000	$ 3,800,000
Minimum [Member]
License Agreement [Line Items]
Percentage of royalty on net sales	7.00%
Maximum [Member]
License Agreement [Line Items]
Percentage of royalty on net sales	10.00%

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Detail) - USD ($)	1 Months Ended	12 Months Ended
	Sep. 30, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
CEO Employment Agreement [Member]
Related Party Transaction [Line Items]
Annual base salary of CEO		$ 485,000
Expiration date of employment agreement		2018-11
Consulting Agreements [Member]
Related Party Transaction [Line Items]
Consulting fees to Company officer and members of the Scientific Advisory Board	$ 45,000	$ 10,000	$ 10,000	$ 10,000

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Statutory rate	34.00%	34.00%	34.00%
Increase in valuation allowance on deferred tax assets	$ 8,287,962	$ 9,413,647
Net operating loss carryforwards	$ 56,300,000	$ 49,900,000
Net operating loss carryforwards expiration date	Beginning in 2023 and ending in 2036.
Effective tax rate	0.00%	0.00%	0.00%
Interest or penalties accrued	$ 0

Income Taxes - Schedule of Reco

Income Taxes - Schedule of Reconciliation of Income Tax Expense (Benefit) Computed at Statutory Federal Income Tax Rate (Detail)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Statutory rate	34.00%	34.00%	34.00%
State tax	3.40%	3.60%	3.70%
Valuation allowance	(44.70%)	(37.70%)	(35.50%)
Tax credit	6.16%	0.00%	0.00%
Other	1.14%	0.10%	(2.20%)
Reconciliation of income tax expense (benefit)	0.00%	0.00%	0.00%

Income Taxes - Components of De

Income Taxes - Components of Deferred Tax Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Components of Deferred Tax Assets [Abstract]
Net operating loss	$ 21,050,217	$ 18,684,232
Start-up cost	12,823,113	9,997,709
Tax credits	6,960,838	3,167,766
Deferred compensation	1,555,425	2,368,352
Other	207,133	90,705
Gross deferred tax asset	42,596,726	34,308,764
Valuation allowance	(42,596,726)	(34,308,764)
Net deferred tax assets	$ 0	$ 0

Stockholders' Equity (Preferred

Stockholders' Equity (Preferred Stock and Common Stock) - Additional Information (Detail)	Dec. 31, 2016Vote$ / sharesshares	Dec. 31, 2015$ / sharesshares	Dec. 31, 2014shares
Equity [Abstract]
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, par value | $ / shares	$ 0.001	$ 0.001
Preferred stock, shares outstanding	0	0
Common stock, shares authorized	150,000,000	150,000,000	100,000,000
Common stock, par value | $ / shares	$ 0.001	$ 0.001
Common stock, shares issued	82,972,316	82,850,619
Common stock, shares outstanding	82,972,316	82,850,619
Number of votes entitled for each share of common stock | Vote	1

Stockholders' Equity (2014 Shel

Stockholders' Equity (2014 Shelf Registration Statement) - Additional Information (Detail) - USD ($)	Feb. 04, 2015	Apr. 03, 2014	Dec. 31, 2016	Jan. 31, 2014
Stockholders' Equity [Line Items]
Maximum dollar amount of common stock to be issued under shelf registration statement				$ 100,000,000
2014 Shelf Registration Statement [Member]
Stockholders' Equity [Line Items]
Maximum dollar amount of common stock to be issued under shelf registration statement				$ 100,000,000
Value of common stock available for future sale			$ 33,800,000
Expiry date of common stock remaining under the shelf registration statement			Mar. 19, 2017
Underwritten Public Offering [Member]
Stockholders' Equity [Line Items]
Number of common stock sold in offering	11,500,000	13,023,750
Common stock issued, price per share	$ 3.25	$ 2.21
Gross proceeds from issuance of common stock	$ 37,400,000	$ 28,800,000
Offering expenses	$ 2,500,000	$ 2,100,000

Stockholders' Equity (2016 Shel

Stockholders' Equity (2016 Shelf Registration Statement) - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 23, 2016	Jan. 31, 2014
Stockholders' Equity [Line Items]
Maximum dollar amount of common stock to be issued under shelf registration statement			$ 100,000,000
2016 Shelf Registration Statement [Member]
Stockholders' Equity [Line Items]
Maximum dollar amount of common stock to be issued under shelf registration statement		$ 33,800,000
Value of public float below which agreed limitation arise	$ 75,000,000
Maximum percentage of outstanding shares that company can sell under shelf registration statement	20.00%

Stockholders' Equity (Warrant E

Stockholders' Equity (Warrant Exercises) - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Equity [Abstract]
Number of warrants exercised during the period	0	1,178,261	1,262,296
Issuance of common stock for warrant exercises		1,178,261	1,262,296
Proceeds from exercise of warrants		$ 1,895,738	$ 1,316,503

Stockholders' Equity (Stockhold

Stockholders' Equity (Stockholder Rights Plan) - Additional Information (Detail) - $ / shares	Sep. 19, 2016	Sep. 20, 2011	Dec. 31, 2016
Series A Preferred Stock [Member]
Stockholders' Equity [Line Items]
Preferred share purchase right price		$ 7.80
Series A Preferred Stock [Member] | Certificate of Designation [Member]
Stockholders' Equity [Line Items]
Junior participating preferred stock shares issued available for issuance under rights agreement, initial			500,000
Junior participating preferred stock shares issued available for issuance under rights agreement, amended			1,500,000
Stockholder Rights Plan [Member]
Stockholders' Equity [Line Items]
Warrants exercise price		$ 7.80
Minimum percentage of outstanding stock acquired by a person or group to trigger Shareholder Rights Plan		17.50%
Stockholders Rights Plan redemption price of right		$ 0.001
Class of warrant or right expiration date	Sep. 20, 2016
Class of warrant or right expiration date, Extended	Sep. 20, 2019

Stock Compensation Plans - Addi

Stock Compensation Plans - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option contractual term	3 years 5 months 9 days
Number of stock options exercised	125,000
Proceeds from exercise of stock options	$ 80,251	$ 390,351	$ 522,000
Stock options granted	1,285,000
Expected dividend rate	0.00%	0.00%	0.00%
2014 Stock Incentive Plan [Member] | Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock shares reserved for issuance under the Plan	6,000,000
Common stock shares available for future issuance under the Plan	2,076,667
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Non-cash stock-based compensation expense	$ 75,494	$ 75,440	$ 10,131
Restricted Stock Units (RSUs) [Member] | Minimum [Member] | Two Thousand Fourteen Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share based compensation, vesting period	3 years
Restricted Stock Units (RSUs) [Member] | Maximum [Member] | Two Thousand Fourteen Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share based compensation, vesting period	4 years
Stock Option [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share based compensation, vesting period	1 year
Stock option contractual term	5 years
Stock Option [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share based compensation, vesting period	3 years
Stock option contractual term	7 years
Options to Purchase Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of stock options exercised	75,000	265,000	580,000
Proceeds from exercise of stock options	$ 80,251	$ 390,351	$ 522,000
Non-cash stock-based compensation expense	$ 1,760,591	$ 1,510,018	$ 767,838
Stock option granted, contractual term	7 years	7 years
Stock options granted	1,285,000	1,760,000	1,305,000
Unrecognized compensation expense related to non-vested stock option awards granted under the Plan	$ 2,320,289
Expected remaining weighted average vesting period	4 years 7 months 28 days
Expected dividend rate	0.00%
Options to Purchase Common Stock [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option granted, contractual term			5 years
Options to Purchase Common Stock [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option granted, contractual term			7 years
Options to Purchase Common Stock [Member] | Cashless Basis [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of stock options exercised	50,000	984,608	185,000
Shares issued for cashless option exercise	20,030	761,600	119,709

Stock Compensation Plans - Summ

Stock Compensation Plans - Summary of Stock Option Activity under the Company's Plan (Detail)	12 Months Ended
	Dec. 31, 2016USD ($)$ / sharesshares
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Number of options, Outstanding at beginning of year | shares	4,250,000
Number of options, Granted | shares	1,285,000
Number of options, Exercised | shares	(125,000)
Number of options, Forfeited or cancelled | shares	(360,000)
Number of options, Expired | shares	(390,000)
Number of options, Outstanding at end of year | shares	4,660,000
Number of options, Exercisable at end of year | shares	2,386,663
Weighted average exercise price, Outstanding at beginning of year | $ / shares	$ 2.23
Weighted average exercise price, Granted | $ / shares	0.94
Weighted average exercise price, Exercised | $ / shares	0.83
Weighted average exercise price, Forfeited or cancelled | $ / shares	3.06
Weighted average exercise price, Expired | $ / shares	1.07
Weighted average exercise price, Outstanding at end of year | $ / shares	1.94
Weighted average exercise price, Exercisable at end of year | $ / shares	$ 2.02
Weighted Average Remaining Contractual Term (Years), Outstanding at end of year	4 years 7 months 28 days
Weighted Average Remaining Contractual Term (Years), Exercisable at end of year	3 years 5 months 9 days
Aggregate Intrinsic value, Outstanding at end of year | $	$ 805,900
Aggregate Intrinsic value, Exercisable at end of year | $	$ 515,500

Stock Compensation Plans - Sche

Stock Compensation Plans - Schedule of Other Information Pertaining to Stock Option Activity (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Weighted-average fair value of granted stock options	$ 0.62	$ 2.13	$ 2.41
Total fair value of vested stock options	$ 1,634,562	$ 1,307,895	$ 409,476
Total intrinsic value of exercised stock options	$ 42,000	$ 3,311,599	$ 1,339,100

Stock Compensation Plans - Su59

Stock Compensation Plans - Summary of Company's Stock Options Outstanding (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of Exercise Prices Lower Range	$ 0.47	$ 0.47	$ 0.47
Range of Exercise Prices Upper Range	$ 4.64	$ 4.64	$ 3.12
Number Outstanding, Options Outstanding	4,660,000
Weighted Average Remaining Contractual Life (Years), Options Outstanding	4 years 7 months 28 days
Weighted Average Exercise Price, Options Outstanding	$ 1.94
Number Exercisable Options Exercisable	2,386,663
Weighted Average Remaining Contractual Life (Years), Options Exercisable	3 years 5 months 9 days
Weighted Average Exercise Price, Options Exercisable	$ 2.02
$0.47 to $0.63 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of Exercise Prices Lower Range	0.47
Range of Exercise Prices Upper Range	$ 0.63
Number Outstanding, Options Outstanding	900,000
Weighted Average Remaining Contractual Life (Years), Options Outstanding	11 months 12 days
Weighted Average Exercise Price, Options Outstanding	$ 0.47
Number Exercisable Options Exercisable	875,000
Weighted Average Remaining Contractual Life (Years), Options Exercisable	11 months 12 days
Weighted Average Exercise Price, Options Exercisable	$ 0.47
$0.64 to $0.82 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of Exercise Prices Lower Range	0.64
Range of Exercise Prices Upper Range	$ 0.82
Number Outstanding, Options Outstanding	1,060,000
Weighted Average Remaining Contractual Life (Years), Options Outstanding	6 years 5 months 12 days
Weighted Average Exercise Price, Options Outstanding	$ 0.79
$0.83 to $2.67 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of Exercise Prices Lower Range	0.83
Range of Exercise Prices Upper Range	$ 2.67
Number Outstanding, Options Outstanding	1,260,000
Weighted Average Remaining Contractual Life (Years), Options Outstanding	5 years 7 months 24 days
Weighted Average Exercise Price, Options Outstanding	$ 2.38
Number Exercisable Options Exercisable	603,333
Weighted Average Remaining Contractual Life (Years), Options Exercisable	5 years 3 months
Weighted Average Exercise Price, Options Exercisable	$ 2.41
$2.68 to $3.23 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of Exercise Prices Lower Range	2.68
Range of Exercise Prices Upper Range	$ 3.23
Number Outstanding, Options Outstanding	1,035,000
Weighted Average Remaining Contractual Life (Years), Options Outstanding	4 years 8 months 1 day
Weighted Average Exercise Price, Options Outstanding	$ 3.11
Number Exercisable Options Exercisable	751,665
Weighted Average Remaining Contractual Life (Years), Options Exercisable	4 years 8 months 1 day
Weighted Average Exercise Price, Options Exercisable	$ 3.11
$3.24 to $4.64 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of Exercise Prices Lower Range	3.24
Range of Exercise Prices Upper Range	$ 4.64
Number Outstanding, Options Outstanding	405,000
Weighted Average Remaining Contractual Life (Years), Options Outstanding	5 years 11 days
Weighted Average Exercise Price, Options Outstanding	$ 3.87
Number Exercisable Options Exercisable	156,665
Weighted Average Remaining Contractual Life (Years), Options Exercisable	4 years 5 months 5 days
Weighted Average Exercise Price, Options Exercisable	$ 3.94

Stock Compensation Plans - Su60

Stock Compensation Plans - Summary of Stock Options Awards Based on Certain Assumptions (Detail)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk free interest rate, Minimum	0.76%	1.00%	1.18%
Risk free interest rate, Maximum	2.15%	2.13%	2.03%
Expected volatility	100.00%	102.00%	115.00%
Expected dividend yield	0.00%	0.00%	0.00%
Expected forfeiture rate	0.00%	0.00%	0.00%
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term	2 years	3 years	3 years
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term	6 years	7 years	7 years

Stock Compensation Plans - Su61

Stock Compensation Plans - Summary of Restricted Stock Unit Activity (Detail) - Restricted Stock Units (RSUs) [Member] - $ / shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Schedule Of Restricted Stock Activity [Line Items]
Nonvested balance at beginning of year	53,334	80,000
Granted			80,000
Vested	(26,667)	(26,666)
Forfeited	0	0	0
Nonvested balance at end of year	26,667	53,334	80,000
Nonvested Weighted Average Grant Date Fair Value balance at beginning of year	$ 2.83	$ 2.83
Weighted Average Grant Date Fair Value, Granted	0	0	$ 0
Weighted Average Grant Date Fair Value, Vested	2.83	2.83	2.83
Weighted Average Grant Date Fair Value, Forfeited	0	0	0
Nonvested Weighted Average Grant Date Fair Value balance at end of year	$ 2.83	$ 2.83	$ 2.83

Benefit Plan - Additional Infor

Benefit Plan - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Compensation and Retirement Disclosure [Abstract]
Employees contribution of pre-tax annual compensation	15.00%
Discretionary matching contributions of employee contributions of an employee's gross salary	4.00%
Contributions	$ 59,000	$ 69,000	$ 44,000

Quarterly Financial Informati63

Quarterly Financial Information (Unaudited) - Schedule of Quarterly Financial Information (Detail) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Revenues	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0
Loss from operations	(4,314,199)	(3,914,014)	(4,814,452)	(6,237,536)	(6,191,679)	(5,017,428)	(4,897,330)	(4,291,915)	(19,280,201)	(20,398,352)	(14,591,428)
Change in fair value of warrants liability	106,946	(106,948)	152,783	733,356	389,596	521,731	333,956	(1,180,278)	886,137	65,005	(993,866)
Net loss	$ (4,163,320)	$ (3,953,981)	$ (4,568,914)	$ (5,386,237)	$ (5,815,158)	$ (4,449,038)	$ (4,558,503)	$ (5,410,259)	$ (18,072,452)	$ (20,232,958)	$ (15,509,061)
Loss per share - basic and diluted	$ (0.05)	$ (0.05)	$ (0.06)	$ (0.07)	$ (0.07)	$ (0.05)	$ (0.06)	$ (0.07)	$ (0.22)	$ (0.25)	$ (0.24)