Catalyst Pharmaceuticals (CPRX) 10-K 15 Mar 16 2015 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2015	Mar. 11, 2016	Jun. 30, 2015
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2015
Document Fiscal Year Focus	2,015
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		82,880,360
Entity Public Float			$ 316,734,842

Balance Sheets

Balance Sheets - USD ($)	Dec. 31, 2015	Dec. 31, 2014
Current Assets:
Cash and cash equivalents	$ 28,235,016	$ 9,096,778
Certificates of deposit	3,717,229	3,715,383
Short-term investments	26,444,150	26,462,962
Prepaid expenses and other current assets	1,504,738	4,552,698
Total current assets	59,901,133	43,827,821
Property and equipment, net	191,549	71,377
Deposits	8,888	8,888
Total assets	60,101,570	43,908,086
Current Liabilities:
Accounts payable	1,794,127	1,814,210
Accrued expenses and other liabilities	1,646,476	4,040,816
Total current liabilities	3,440,603	5,855,026
Accrued expenses and other liabilities, non-current	176,293	15,839
Warrants liability, at fair value	1,008,363	2,794,891
Total liabilities	$ 4,625,259	$ 8,665,756
Commitments and contingencies
Stockholders' equity:
Preferred stock, $0.001 par value, 5,000,000 shares authorized: none issued and outstanding at December 31, 2015 and 2014
Common stock, $0.001 par value, 150,000,000 and 100,000,000 shares authorized; 82,850,619 shares and 69,119,092 shares issued and outstanding at December 31, 2015 and 2014, respectively	$ 82,851	$ 69,119
Additional paid-in capital	145,469,078	105,015,871
Accumulated deficit	(90,075,618)	(69,842,660)
Total stockholders' equity	55,476,311	35,242,330
Total liabilities and stockholders' equity	$ 60,101,570	$ 43,908,086

Balance Sheets (Parenthetical)

Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2015	Dec. 31, 2014
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	100,000,000
Common stock, shares issued	82,850,619	69,119,092
Common stock, shares outstanding	82,850,619	69,119,092

Statements of Operations

Statements of Operations - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Statement [Abstract]
Revenues	$ 0	$ 0	$ 0
Operating costs and expenses:
Research and development	11,801,342	10,117,774	8,096,774
General and administrative	8,597,010	4,473,654	2,214,884
Total operating costs and expenses	20,398,352	14,591,428	10,311,658
Loss from operations	(20,398,352)	(14,591,428)	(10,311,658)
Other income, net	100,389	76,233	47,421
Change in fair value of warrants liability	65,005	(993,866)	(1,890,359)
Loss before income taxes	(20,232,958)	(15,509,061)	(12,154,596)
Provision for income taxes	0	0	0
Net loss	$ (20,232,958)	$ (15,509,061)	$ (12,154,596)
Net loss per share - basic and diluted	$ (0.25)	$ (0.24)	$ (0.27)
Weighted average shares outstanding - basic and diluted	80,858,393	64,142,534	45,452,447

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, 2012	$ 14,622,115	$ 41,421	$ 56,759,697	$ (42,179,003)
Issuance of common stock, net	14,095,194	8,850	14,086,344
Issuance of stock options for services	175,855		175,855
Exercise of warrants for common stock	4,652,684	3,862	4,648,822
Net loss	(12,154,596)			(12,154,596)
Ending 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)

Statements of Cash Flows

Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Operating Activities:
Net loss	$ (20,232,958)	$ (15,509,061)	$ (12,154,596)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	34,468	26,574	22,483
Stock-based compensation	1,585,458	777,969	175,855
Change in fair value of warrants liability	(65,005)	993,866	1,890,359
(Increase) decrease in:
Prepaid expenses and other current assets and deposits	(452,040)	(2,943,256)	(299,972)
Increase (decrease) in:
Accounts payable	(20,083)	963,421	(514,874)
Accrued expenses and other liabilities	1,134,939	2,748,704	1,005,071
Net cash used in operating activities	(18,015,221)	(12,941,783)	(9,875,674)
Investing Activities:
Capital expenditures	(23,465)	(57,323)	(9,432)
Proceeds (purchase) of short-term investments	18,812	(8,979,900)	(9,978,618)
Proceeds (purchase) of certificates of deposit	(1,846)	296,193	2,491,249
Net cash used in investing activities	(6,499)	(8,741,030)	(7,496,801)
Financing Activities:
Proceeds from issuance of common stock and warrants, net	34,873,869	26,725,130	14,071,694
Proceeds from exercise of warrants	1,895,738	1,316,503	4,083,300
Proceeds from exercise of options	390,351	522,000	23,500
Net cash provided by financing activities	37,159,958	28,563,633	18,178,494
Net increase (decrease) in cash and cash equivalents	19,138,238	6,880,820	806,019
Cash and cash equivalents - beginning of period	9,096,778	2,215,958	1,409,939
Cash and cash equivalents - end of period	28,235,016	9,096,778	2,215,958
Non-cash investing and financing activities:
Exercise of liability classified warrants for common stock	1,721,523	$ 18,537	$ 569,384
Non-cash incentive received from lessor	$ 131,175

Organization and Description of

Organization and Description of Business	12 Months Ended
	Dec. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Description of Business	1. Organization and Description of Business Catalyst Pharmaceuticals, Inc., formerly known as Catalyst Pharmaceutical Partners, 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), infantile spasms and Tourette’s Disorder. The Company 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, 2015. 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 (the 2014 Shelf Registration Statement) with the U.S. Securities and Exchange Commission (SEC) to sell up to $100 million of common stock. This registration statement (file No. 333-193699) was declared effective by the SEC on March 19, 2014. The Company has conducted two registered direct offerings under the 2014 Shelf Registration Statement. (See Note 11). While there can be no assurance, based on currently available information, the Company estimates that it currently has sufficient working capital to support its operations through the first quarter of 2017. The Company will require additional capital to support its operations in periods after the first quarter of 2017. 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, 2015
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. 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 $ 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 Fair Value Measurements at Reporting Date Using Balances as of Quoted Prices in Significant Significant Money market funds $ 7,053,310 $ 7,053,310 $ — $ — Certificates of deposit $ 3,715,383 $ — $ 3,715,383 $ — Short-term investments $ 26,462,962 $ 26,462,962 $ — $ — Warrants liability $ 2,794,891 $ — $ — $ 2,794,891 j. WARRANTS LIABILITY. k. RESEARCH AND DEVELOPMENT. l. STOCK-BASED COMPENSATION. For the years ended December 31, 2015, 2014 and 2013, the Company recorded stock-based compensation expense as follows: 2015 2014 2013 Research and development $ 378,548 $ 133,862 $ 84,728 General and administrative 1,206,910 644,107 91,127 Total stock-based compensation $ 1,585,458 $ 777,969 $ 175,855 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 threshold, the amount recognized in the financial statements is the largest benefit that has a greater than 50 percent likelihood of being realized upon ultimate settlement with the relevant tax authority. 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 2012. 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. 2015 2014 2013 Stock options to purchase common stock 4,250,000 3,884,610 3,428,906 Warrants to purchase common stock 2,407,663 3,585,924 4,848,620 Unvested restricted stock 53,334 80,000 — Potential equivalent common stock excluded 6,710,997 7,550,534 8,277,526 Potentially dilutive stock options to purchase common stock as of 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 stock options to purchase common stock as of December 31, 2013 have exercise prices ranging from $0.47 to $6.00. Potentially dilutive warrants to purchase common stock as of December 31, 2015, 2014 and 2013 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. Elimination of Certain Financial Reporting Requirements Including an Amendment to Variable Interest Entities Guidance in Topic 810, Consolidation In August 2014, the FASB issued ASU No. 2014-15, Presentation of Financial Statements—Going Concern (Subtopic 205-40): Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern. In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842)

Warrants Liability, at Fair Val

Warrants Liability, at Fair Value	12 Months Ended
	Dec. 31, 2015
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 input, the Company determined the 2011 warrants liability is most appropriately classified within Level 3 of the fair value hierarchy. This liability is subject to fair value mark-to-market adjustment each reporting period. The calculated value of the 2011 warrants liability was determined using the Black-Scholes option-pricing model with the following assumptions: December 31, 2015 December 31, 2014 Risk free interest rate 0.79 % 0.81 % Expected term 1.34 years 2.34 years Expected volatility 68 % 112 % 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, 2015, 2014 and 2013: 2015 2014 2013 Fair value, beginning of period $ 2,794,891 $ 1,819,562 $ 498,587 Issuance of warrants — — — Exercise of warrants (1,721,523 ) (18,537 ) (569,384 ) Change in fair value (65,005 ) 993,866 1,890,359 Fair value, end of period $ 1,008,363 $ 2,794,891 $ 1,819,562 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. During 2013, 256,000 of the 2011 warrants were exercised, with proceeds to the Company of $332,800. The Company recognizes the change in the fair value of the warrants liability as a non-operating income or loss in the accompanying statements of operations.

Prepaid Expenses and Other Curr

Prepaid Expenses and Other Current Assets	12 Months Ended
	Dec. 31, 2015
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: 2015 2014 Insurance recoverable (see Note 7) $ — $ 3,500,000 Prepaid research fees 915,194 571,428 Prepaid insurance 436,726 385,496 Prepaid pre-commercialization fees 90,248 4,065 Prepaid subscriptions fees 26,602 30,495 Prepaid offering costs — 20,029 Prepaid rent 1,252 10,870 Other 34,716 30,315 Total prepaid expenses and other current assets $ 1,504,738 $ 4,552,698

Property and Equipment

Property and Equipment	12 Months Ended
	Dec. 31, 2015
Property, Plant and Equipment [Abstract]
Property and Equipment	5. Property and Equipment Property and equipment, net consists of the following as of December 31: 2015 2014 Computer equipment $ 27,915 $ 95,754 Furniture and equipment 102,533 88,816 Leasehold improvements 131,175 — 261,623 184,570 Less: Accumulated depreciation (70,074 ) (113,193 ) Total property and equipment, net $ 191,549 $ 71,377 Depreciation expense was $34,468, $26,574 and $22,483, respectively, for the years ended December 31, 2015, 2014 and 2013.

Accrued Expenses and Other Liab

Accrued Expenses and Other Liabilities	12 Months Ended
	Dec. 31, 2015
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: 2015 2014 Accrued settlement liability (see Note 7) $ — $ 3,500,000 Accrued preclinical and clinical trial expenses 332,905 333,928 Accrued professional fees 330,490 43,973 Accrued compensation and benefits 894,846 31,956 Accrued license fees 52,500 115,000 Deferred rent and lease incentive 18,093 4,158 Other 17,642 11,801 Current accrued expenses and other liabilities 1,646,476 4,040,816 Deferred rent and lease incentive—non-current 176,293 15,839 Non-current accrued expenses and other liabilities 176,293 15,839 Total accrued expenses and other liabilities $ 1,822,769 $ 4,056,655 The accrued settlement liability of $3,500,000 as of December 31, 2014 is related to the securities class action lawsuit settlement, as disclosed with more particularity in Note 7. The settlement amount was covered by the Company’s insurance carrier; therefore, there was a corresponding insurance recoverable recorded in “Prepaid Expenses and Other Current Assets” in the accompanying balance sheet as of December 31, 2014.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2015
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 operating lease agreement for its corporate office. The lease has free and escalating rent payment provisions. The Company recognizes rent expense under such lease on a straight-line basis over the term of the lease. As of December 31, 2015, future minimum lease payments under the operating lease agreement are as follows: 2016 $ 185,244 2017 207,421 2018 213,644 2019 220,053 2020 226,655 Thereafter 453,478 $ 1,506,495 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 costs were funded and paid by the landlord through lease incentives. The lease incentives are being amortized over the term of the lease as a reduction of rent expense. The lease provides for fixed increases in minimum annual rent payments, as well as rent free periods. The total amount of rental payments due over the lease term is being charged to rent expense on the straight-line method over the term of the lease. The differences between rent expense recorded and the amount paid is credited or charged to accrued expenses and other liabilities in the accompanying balance sheets. Rent expense was $129,727, $90,163 and $69,930 respectively, for the years ended December 31, 2015, 2014 and 2013. Obligations under capital leases are not significant. For commitments related to the Company’s license agreements with BioMarin (defined below) and Northwestern (defined below), see Note 8. Securities Class Action Lawsuit In October 2013 and November 2013, three securities class action lawsuits were filed against the Company and certain of its executive officers and directors seeking unspecified damages in the U.S. District Court for the Southern District of Florida (the Court). These complaints, which were substantially identical, purported to state a claim for violation of federal securities laws on behalf of a class of those who purchased the Company’s common stock between October 31, 2012 and October 18, 2013. Two of the cases were voluntarily dismissed by the plaintiffs and the Court granted the Company’s motion to dismiss on the third case on January 3, 2014. However, the Court granted leave to the plaintiffs to file an amended complaint within 20 days. On January 23, 2014, the plaintiffs filed an amended complaint against the Company and one of its executive officers seeking unspecified damages. The amended complaint purported to state a claim for alleged misrepresentations regarding the development of Firdapse ® Following a mediation in October 2014 conducted by an independent mediator, the Company entered into a memorandum of understanding (MOU) with the lead plaintiffs in the class action lawsuit to settle the lawsuit. The settlement was then reduced to a formal stipulation of settlement between the parties to the lawsuit, which was filed with the Court on November 21, 2014. The settlement was approved by the Court in March 2015 and became final on April 16, 2015. The Company paid $3.5 million to settle this matter, all of which was paid by the Company’s insurance carrier. Under the settlement, the defendants, and various of their related persons and entities, received a full release of all claims that were or could have been brought in the action, as well as all claims that arise out of, are based upon, or relate to the allegations, transactions, facts, representations, omissions or other matters involved in the action related in any way to the purchase or acquisition of the Company’s securities by class members during the class period. The settlement contains no admission of any liability or wrongdoing on the part of the defendants, each of whom continues to deny all of the allegations against each of them and believe that the claims were without merit. Because the full amount of the settlement payment was paid by the Company’s insurance carrier, the settlement did not have a material adverse effect on the Company’s financial position or results of operations. There were no opt outs from the settlement.

Agreements

Agreements	12 Months Ended
	Dec. 31, 2015
Text Block [Abstract]
Agreements	8. Agreements a. LICENSE AGREEMENT WITH NORTHWESTERN UNIVERSITY. 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 took over a Phase 3 Trial previously being conducted by BioMarin evaluating Firdapse ® As part of the License Agreement, the Company has 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, 2015
Related Party Transactions [Abstract]
Related Party Transactions	9. Related Party Transactions The Company has entered into consulting agreements with one of the Company’s directors and members of the Company’s Scientific Advisory Board. During the years ended December 31, 2015, 2014 and 2013, the Company paid approximately $55,000, $10,000 and $10,000, respectively, in consulting fees to related parties. The Company has an employment agreement with its Chief Executive Officer. Under this agreement, the CEO will receive an annual base salary of approximately $471,000 in 2016, and may earn bonus compensation of up to 50% of his salary based on performance. This agreement expires in November 2016.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Income Taxes	10. Income Taxes As of December 31, 2015 and 2014, the Company had deferred tax assets of approximately $34,309,000 and $24,895,000, respectively, of which approximately $28,682,000 and $22,898,000 represent United States federal and state net operating loss carryforwards and start-up costs. The remaining temporary differences represent non-deductible stock option and equity expense. The related deferred tax asset has a 100% valuation allowance as of December 31, 2015 and 2014, as the Company believes it is more likely than not that the deferred tax asset will not be realized. The change in valuation allowance was approximately $9,414,000, $5,508,000 and $3,796,000 in 2015, 2014 and 2013, respectively. There are no other significant temporary differences. The net operating loss carry-forwards of approximately $49,922,000 as of December 31, 2015 will expire at various dates beginning in 2023 and ending in 2035. 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 35% due to the valuation allowance and because the Company had no taxable income.

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2015
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, 2015 and 2014. No shares of preferred stock were outstanding at December 31, 2015 and 2014. 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, 2015 and 2014, 82,850,619 and 69,119,092 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 (the 2014 Shelf Registration Statement) with the SEC to sell up to $100 million of shares of common stock. This registration statement (file No. 333-193699) was declared effective by the SEC on March 19, 2014. The Company has to date conducted the following sales of its securities under the 2014 Shelf Registration Statement: (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, 2015, there is approximately $33.8 million available for future sale under the 2014 Shelf Registration Statement. If the Company’s public float (the market value of its common stock held by non-affiliate stockholders) were to fall below $75 million, the Company would be subject to a further limitation under which it could sell no more than one-third (1/3) of its public float during any 12-month period. Further, the number of shares that the Company can sell at any one time may be limited under certain circumstances to 20% of the outstanding common stock under applicable NASDAQ marketplace rules. Warrant Exercises During the years ended December 31, 2015, 2014 and 2013, the Company issued an aggregate of 1,178,261, 1,262,296 and 3,862,250 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, $1,316,503 and $4,083,300, 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 of a share of Series A Junior Preferred Stock at a purchase price of $7.80, subject to adjustment. 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. The Rights will expire on September 20, 2016, unless earlier redeemed or exchanged.

Stock Compensation Plans

Stock Compensation Plans	12 Months Ended
	Dec. 31, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock Compensation Plans	12. Stock Compensation Plans The Company issues 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, 2014, no shares remain available for future issuance under the 2006 Plan. Under the 2014 Plan, 4,000,000 shares were reserved for issuance and as of December 31, 2015, 1,050,000 shares remain available for future issuance. Stock Options 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, 2015 and 2014, options to purchase 265,000 and 580,000 shares of the Company’s common stock were exercised with gross proceeds to the Company of $390,351 and $522,000, respectively. Further, during the years ended December 31, 2015 and 2014, options to purchase 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 761,600 and 119,709 shares of the Company’s common stock, respectively. During the year ended December 31, 2013, options to purchase 50,000 shares of the Company’s common stock were exercised, with gross proceeds to the Company of $23,500. During the years ended December 31, 2015, 2014 and 2013 the Company recorded non-cash stock-based compensation expense related to stock options totaling $1,510,018, $767,838 and $175,855, respectively. During the year ended December 31, 2015, the Company granted seven-year options to purchase an aggregate of 1,760,000 shares 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. During the year ended December 31, 2013, the Company granted five-year options to purchase an aggregate of 115,000 shares, respectively, 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, 2015 is summarized as follows: Number of Weighted Weighted Aggregate Outstanding at beginning of year 3,884,610 $ 1.50 Granted 1,760,000 3.02 Exercised (1,249,608 ) 0.95 Forfeited or cancelled (145,002 ) 3.30 Expired — — Outstanding at end of year 4,250,000 $ 2.23 4.75 $ 2,589,800 Exercisable at end of year 2,036,663 $ 1.38 2.93 $ 2,517,634 Other information pertaining to stock option activity during the years ended December 31, 2015, 2014 and 2013 was as follows: 2015 2014 2013 Weighted-average fair value of granted stock options $ 2.13 $ 2.41 $ 0.48 Total fair value of vested stock options $ 1,307,895 $ 409,476 $ 166,633 Total intrinsic value of exercised stock options $ 3,311,599 $ 1,339,100 $ 17,975 The following table summarizes information about the Company’s options outstanding at December 31, 2015: Options Outstanding Options Exercisable Range of Exercise Prices Number Weighted Weighted Number Weighted Weighted $0.47 950,000 1.97 $ 0.47 925,000 1.96 $ 0.47 $0.85 to $2.35 535,000 1.20 $ 1.13 508,333 1.11 $ 1.10 $2.53 1,140,000 7.00 $ 2.53 120,000 7.00 $ 2.53 $2.62 to $3.12 1,060,000 5.69 $ 3.10 483,330 5.66 $ 3.12 $3.34 to $4.64 565,000 6.47 $ 3.97 0 0.00 $ 0.00 4,250,000 4.75 $ 2.23 2,036,663 2.93 $ 1.38 As of December 31, 2015, there was approximately $4,290,447 of unrecognized compensation expense related to non-vested stock option awards granted under the Plans. That cost is expected to be recognized over a weighted average period of approximately 2.3 years. 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. The Company estimates the expected option life for options granted to employees and directors based upon the simplified method. Under this method, the expected life is presumed to be the mid-point between the vesting date and the end of the contractual term. The Company will continue to use the simplified method until it has sufficient historical exercise data to estimate the expected life of the options. The risk-free interest rate assumption is based upon the U.S. Treasury yield curve appropriate for the estimated life of the stock options awards. The expected dividend rate is zero. Stock–based compensation expense also includes an estimate, which the Company makes at grant date, of the number of awards that are expected to be forfeited. The Company revises this estimate in subsequent periods if actual forfeitures differ from those estimates. Assumptions used during the years were as follows: Year ended December 31, 2015 2014 2013 Risk free interest rate 1.00% to 2.13% 1.18% to 2.03% 0.45% to 0.53% Expected term 3 to 7 years 3 to 7 years 3 years Expected volatility 102% 115% 137% 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. There was no restricted stock unit activity during 2013. Restricted stock unit activity during 2015 and 2014 was as follows: 2015 2014 Number of Weighted Number of Weighted Nonvested balance at beginning of year 80,000 $ 2.83 — $ — Granted — — 80,000 — Vested (26,666 ) 2.83 — 2.83 Forfeited — — — — Nonvested balance at end of year 53,334 $ 2.83 80,000 $ 2.83 During the years ended December 31, 2015, 2014 and 2013, the Company recorded non-cash stock-based compensation expense related to restricted stock units totaling $75,440, $10,131 and $0, respectively.

Benefit Plan

Benefit Plan	12 Months Ended
	Dec. 31, 2015
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 annual compensation to the plan. The Company has elected to make discretionary matching contributions of employee contributions up to 4% of an employee’s gross salary. For the years ended December 31, 2015, 2014 and 2013, the Company’s matching contributions were approximately $69,000, $44,000 and $30,000, respectively.

Quarterly Financial Information

Quarterly Financial Information (unaudited)	12 Months Ended
	Dec. 31, 2015
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, 2015 and 2014: 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 ) Quarter Ended March 31, June 30, 2014 September 30, December 31, Revenues $ — $ — $ — $ — Loss from operations (3,508,365 ) (2,990,173 ) (4,109,029 ) (3,983,861 ) Change in fair value of warrants liability (335,514 ) (223,591 ) (906,787 ) 472,026 Net loss (3,811,119 ) (3,198,020 ) (5,009,892 ) (3,490,030 ) Loss per share — basic and diluted $ (0.07 ) $ (0.05 ) $ (0.07 ) $ (0.05 ) 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.

Subsequent Event

Subsequent Event	12 Months Ended
	Dec. 31, 2015
Subsequent Events [Abstract]
Subsequent Event	15. Subsequent Event Subsequent to year end, during February 2016, the Company received a “Refusal to File” letter from the FDA regarding its NDA for Firdapse ® ® ®

Basis of Presentation and Sig22

Basis of Presentation and Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2015
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.
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 $ 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 Fair Value Measurements at Reporting Date Using Balances as of Quoted Prices in Significant Significant Money market funds $ 7,053,310 $ 7,053,310 $ — $ — Certificates of deposit $ 3,715,383 $ — $ 3,715,383 $ — Short-term investments $ 26,462,962 $ 26,462,962 $ — $ — Warrants liability $ 2,794,891 $ — $ — $ 2,794,891
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, 2015, 2014 and 2013, the Company recorded stock-based compensation expense as follows: 2015 2014 2013 Research and development $ 378,548 $ 133,862 $ 84,728 General and administrative 1,206,910 644,107 91,127 Total stock-based compensation $ 1,585,458 $ 777,969 $ 175,855
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 threshold, the amount recognized in the financial statements is the largest benefit that has a greater than 50 percent likelihood of being realized upon ultimate settlement with the relevant tax authority. 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 2012. 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. 2015 2014 2013 Stock options to purchase common stock 4,250,000 3,884,610 3,428,906 Warrants to purchase common stock 2,407,663 3,585,924 4,848,620 Unvested restricted stock 53,334 80,000 — Potential equivalent common stock excluded 6,710,997 7,550,534 8,277,526 Potentially dilutive stock options to purchase common stock as of 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 stock options to purchase common stock as of December 31, 2013 have exercise prices ranging from $0.47 to $6.00. Potentially dilutive warrants to purchase common stock as of December 31, 2015, 2014 and 2013 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. Elimination of Certain Financial Reporting Requirements Including an Amendment to Variable Interest Entities Guidance in Topic 810, Consolidation In August 2014, the FASB issued ASU No. 2014-15, Presentation of Financial Statements—Going Concern (Subtopic 205-40): Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern. In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842)

Basis of Presentation and Sig23

Basis of Presentation and Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2015
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 $ 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 Fair Value Measurements at Reporting Date Using Balances as of Quoted Prices in Significant Significant Money market funds $ 7,053,310 $ 7,053,310 $ — $ — Certificates of deposit $ 3,715,383 $ — $ 3,715,383 $ — Short-term investments $ 26,462,962 $ 26,462,962 $ — $ — Warrants liability $ 2,794,891 $ — $ — $ 2,794,891
Stock-Based Compensation Expense	For the years ended December 31, 2015, 2014 and 2013, the Company recorded stock-based compensation expense as follows: 2015 2014 2013 Research and development $ 378,548 $ 133,862 $ 84,728 General and administrative 1,206,910 644,107 91,127 Total stock-based compensation $ 1,585,458 $ 777,969 $ 175,855
Potential Shares Excluded from Determination of Basic and Diluted Net Loss Per Share	p. NET INCOME (LOSS) PER SHARE. 2015 2014 2013 Stock options to purchase common stock 4,250,000 3,884,610 3,428,906 Warrants to purchase common stock 2,407,663 3,585,924 4,848,620 Unvested restricted stock 53,334 80,000 — Potential equivalent common stock excluded 6,710,997 7,550,534 8,277,526

Warrants Liability, at Fair V24

Warrants Liability, at Fair Value (Tables)	12 Months Ended
	Dec. 31, 2015
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, 2015, 2014 and 2013: 2015 2014 2013 Fair value, beginning of period $ 2,794,891 $ 1,819,562 $ 498,587 Issuance of warrants — — — Exercise of warrants (1,721,523 ) (18,537 ) (569,384 ) Change in fair value (65,005 ) 993,866 1,890,359 Fair value, end of period $ 1,008,363 $ 2,794,891 $ 1,819,562
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, 2015 December 31, 2014 Risk free interest rate 0.79 % 0.81 % Expected term 1.34 years 2.34 years Expected volatility 68 % 112 % Expected dividend yield 0 % 0 % Expected forfeiture rate 0 % 0 %

Prepaid Expenses and Other Cu25

Prepaid Expenses and Other Current Assets (Tables)	12 Months Ended
	Dec. 31, 2015
Text Block [Abstract]
Prepaid Expenses	Prepaid expenses and other current assets consist of the following as of December 31: 2015 2014 Insurance recoverable (see Note 7) $ — $ 3,500,000 Prepaid research fees 915,194 571,428 Prepaid insurance 436,726 385,496 Prepaid pre-commercialization fees 90,248 4,065 Prepaid subscriptions fees 26,602 30,495 Prepaid offering costs — 20,029 Prepaid rent 1,252 10,870 Other 34,716 30,315 Total prepaid expenses and other current assets $ 1,504,738 $ 4,552,698

Property and Equipment (Tables)

Property and Equipment (Tables)	12 Months Ended
	Dec. 31, 2015
Property, Plant and Equipment [Abstract]
Property and Equipment, Net	Property and equipment, net consists of the following as of December 31: 2015 2014 Computer equipment $ 27,915 $ 95,754 Furniture and equipment 102,533 88,816 Leasehold improvements 131,175 — 261,623 184,570 Less: Accumulated depreciation (70,074 ) (113,193 ) Total property and equipment, net $ 191,549 $ 71,377

Accrued Expenses and Other Li27

Accrued Expenses and Other Liabilities (Tables)	12 Months Ended
	Dec. 31, 2015
Payables and Accruals [Abstract]
Schedule of Accrued Expenses and Other Liabilities	Accrued expenses and other liabilities consist of the following as of December 31: 2015 2014 Accrued settlement liability (see Note 7) $ — $ 3,500,000 Accrued preclinical and clinical trial expenses 332,905 333,928 Accrued professional fees 330,490 43,973 Accrued compensation and benefits 894,846 31,956 Accrued license fees 52,500 115,000 Deferred rent and lease incentive 18,093 4,158 Other 17,642 11,801 Current accrued expenses and other liabilities 1,646,476 4,040,816 Deferred rent and lease incentive—non-current 176,293 15,839 Non-current accrued expenses and other liabilities 176,293 15,839 Total accrued expenses and other liabilities $ 1,822,769 $ 4,056,655

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Future Minimum Lease Payments under Operating Lease Agreement	As of December 31, 2015, future minimum lease payments under the operating lease agreement are as follows: 2016 $ 185,244 2017 207,421 2018 213,644 2019 220,053 2020 226,655 Thereafter 453,478 $ 1,506,495

Stock Compensation Plans (Table

Stock Compensation Plans (Tables)	12 Months Ended
	Dec. 31, 2015
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, 2015 is summarized as follows: Number of Weighted Weighted Aggregate Outstanding at beginning of year 3,884,610 $ 1.50 Granted 1,760,000 3.02 Exercised (1,249,608 ) 0.95 Forfeited or cancelled (145,002 ) 3.30 Expired — — Outstanding at end of year 4,250,000 $ 2.23 4.75 $ 2,589,800 Exercisable at end of year 2,036,663 $ 1.38 2.93 $ 2,517,634
Schedule of Other Information Pertaining to Stock Option Activity	Other information pertaining to stock option activity during the years ended December 31, 2015, 2014 and 2013 was as follows: 2015 2014 2013 Weighted-average fair value of granted stock options $ 2.13 $ 2.41 $ 0.48 Total fair value of vested stock options $ 1,307,895 $ 409,476 $ 166,633 Total intrinsic value of exercised stock options $ 3,311,599 $ 1,339,100 $ 17,975
Summary of Company's Stock Options Outstanding	The following table summarizes information about the Company’s options outstanding at December 31, 2015: Options Outstanding Options Exercisable Range of Exercise Prices Number Weighted Weighted Number Weighted Weighted $0.47 950,000 1.97 $ 0.47 925,000 1.96 $ 0.47 $0.85 to $2.35 535,000 1.20 $ 1.13 508,333 1.11 $ 1.10 $2.53 1,140,000 7.00 $ 2.53 120,000 7.00 $ 2.53 $2.62 to $3.12 1,060,000 5.69 $ 3.10 483,330 5.66 $ 3.12 $3.34 to $4.64 565,000 6.47 $ 3.97 0 0.00 $ 0.00 4,250,000 4.75 $ 2.23 2,036,663 2.93 $ 1.38
Summary of Stock Options Awards Based on Certain Assumptions	Assumptions used during the years were as follows: Year ended December 31, 2015 2014 2013 Risk free interest rate 1.00% to 2.13% 1.18% to 2.03% 0.45% to 0.53% Expected term 3 to 7 years 3 to 7 years 3 years Expected volatility 102% 115% 137% Expected dividend yield — % — % — % Expected forfeiture rate — % — % — %
Summary of Restricted Stock Unit Activity	Restricted stock unit activity during 2015 and 2014 was as follows: 2015 2014 Number of Weighted Number of Weighted Nonvested balance at beginning of year 80,000 $ 2.83 — $ — Granted — — 80,000 — Vested (26,666 ) 2.83 — 2.83 Forfeited — — — — Nonvested balance at end of year 53,334 $ 2.83 80,000 $ 2.83

Quarterly Financial Informati30

Quarterly Financial Information (unaudited) (Tables)	12 Months Ended
	Dec. 31, 2015
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, 2015 and 2014: 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 ) Quarter Ended March 31, June 30, 2014 September 30, December 31, Revenues $ — $ — $ — $ — Loss from operations (3,508,365 ) (2,990,173 ) (4,109,029 ) (3,983,861 ) Change in fair value of warrants liability (335,514 ) (223,591 ) (906,787 ) 472,026 Net loss (3,811,119 ) (3,198,020 ) (5,009,892 ) (3,490,030 ) Loss per share — basic and diluted $ (0.07 ) $ (0.05 ) $ (0.07 ) $ (0.05 )

Organization and Description 31

Organization and Description of Business - Additional Information (Detail) - 2014 Shelf Registration Statement [Member]	12 Months Ended
	Dec. 31, 2015Offerings	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

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, 2015USD ($)Segment$ / sharesshares	Dec. 31, 2014USD ($)$ / sharesshares	Dec. 31, 2013$ / 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 | $		$ 194,386	$ 19,997
Stock option exercise price range, Minimum		$ 0.47	$ 0.47	$ 0.47
Stock option exercise price range, Maximum		$ 4.64	$ 3.12	6
Number of reportable segment | Segment		1
October 28, 2011 Warrants [Member] | 2010 Shelf Registration Statement [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	1,242,174
Leasehold Improvements [Member]
Summary Of Basis Of Presentation And Significant Accounting Policies [Line Items]
Useful life of assets		7 years
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] | 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] | 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, 2015	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Certificates of deposit	$ 3,717,229	$ 3,715,383
Short-term investments	26,444,150	26,462,962
Warrants liability	1,008,363	2,794,891
Money Market Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market funds	25,157,601	7,053,310
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	26,444,150	26,462,962
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	25,157,601	7,053,310
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	3,715,383
Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Warrants liability	$ 1,008,363	$ 2,794,891

Basis of Presentation and Sig34

Basis of Presentation and Significant Accounting Policies - Stock-Based Compensation Expense (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation	$ 1,585,458	$ 777,969	$ 175,855
Research and Development [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation	378,548	133,862	84,728
General and Administrative [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation	$ 1,206,910	$ 644,107	$ 91,127

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, 2015	Dec. 31, 2014	Dec. 31, 2013
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential equivalent common stock excluded	6,710,997	7,550,534	8,277,526
Options to Purchase Common Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential equivalent common stock excluded	4,250,000	3,884,610	3,428,906
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	3,585,924	4,848,620
Unvested Restricted Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential equivalent common stock excluded	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, 2015	Dec. 31, 2014	Dec. 31, 2013
Class of Warrant or Right [Line Items]
Recognition of warrants fair value at date of issuance		$ 0	$ 0	$ 0
Proceeds from exercise of warrants		$ 1,895,738	$ 1,316,503	$ 4,083,300
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		478,261	12,696	256,000
Proceeds from exercise of warrants		$ 621,739	$ 16,504	$ 332,800

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, 2015	Dec. 31, 2014
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Risk free interest rate	0.79%	0.81%
Expected term	1 year 4 months 2 days	2 years 4 months 2 days
Expected volatility	68.00%	112.00%
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, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Fair Value Disclosures [Abstract]
Fair value, beginning of period				$ 2,794,891				$ 1,819,562	$ 2,794,891	$ 1,819,562	$ 498,587
Issuance of warrants									0	0	0
Exercise of warrants									(1,721,523)	(18,537)	(569,384)
Change in fair value	$ (389,596)	$ (521,731)	$ (333,956)	$ 1,180,278	$ (472,026)	$ 906,787	$ 223,591	$ 335,514	(65,005)	993,866	1,890,359
Fair value, end of period	$ 1,008,363				$ 2,794,891				$ 1,008,363	$ 2,794,891	$ 1,819,562

Prepaid Expenses and Other Cu39

Prepaid Expenses and Other Current Assets - Prepaid Expenses (Detail) - USD ($)	Dec. 31, 2015	Dec. 31, 2014
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Insurance recoverable		$ 3,500,000
Prepaid research fees	$ 915,194	571,428
Prepaid insurance	436,726	385,496
Prepaid pre-commercialization fees	90,248	4,065
Prepaid subscription fees	26,602	30,495
Prepaid offering costs		20,029
Prepaid rent	1,252	10,870
Other	34,716	30,315
Total prepaid expenses and other current assets	$ 1,504,738	$ 4,552,698

Property and Equipment - Proper

Property and Equipment - Property and Equipment, Net (Detail) - USD ($)	Dec. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 261,623	$ 184,570
Less: Accumulated depreciation	(70,074)	(113,193)
Total property and equipment, net	191,549	71,377
Computer Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	27,915	95,754
Furniture and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	102,533	$ 88,816
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 131,175

Property and Equipment - Additi

Property and Equipment - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Property, Plant and Equipment [Abstract]
Depreciation expenses	$ 34,468	$ 26,574	$ 22,483

Accrued Expenses and Other Li42

Accrued Expenses and Other Liabilities - Schedule of Accrued Expenses and Other Liabilities (Detail) - USD ($)	Dec. 31, 2015	Dec. 31, 2014
Payables and Accruals [Abstract]
Accrued settlement liability		$ 3,500,000
Accrued preclinical and clinical trial expenses	$ 332,905	333,928
Accrued professional fees	330,490	43,973
Accrued compensation and benefits	894,846	31,956
Accrued license fees	52,500	115,000
Deferred rent and lease incentive	18,093	4,158
Other	17,642	11,801
Current accrued expenses and other liabilities	1,646,476	4,040,816
Deferred rent and lease incentive - non-current	176,293	15,839
Non-current accrued expenses and other liabilities	176,293	15,839
Total accrued expenses and other liabilities	$ 1,822,769	$ 4,056,655

Accrued Expenses and Other Li43

Accrued Expenses and Other Liabilities - Additional Information (Detail)	Dec. 31, 2014USD ($)
Payables and Accruals [Abstract]
Accrued settlement liability	$ 3,500,000

Commitments and Contingencies -

Commitments and Contingencies - Future Minimum Lease Payments under Operating Lease Agreement (Detail)	Dec. 31, 2015USD ($)
Commitments and Contingencies Disclosure [Abstract]
2,016	$ 185,244
2,017	207,421
2,018	213,644
2,019	220,053
2,020	226,655
Thereafter	453,478
Total	$ 1,506,495

Commitments and Contingencies45

Commitments and Contingencies - Additional Information (Detail)	1 Months Ended		2 Months Ended	12 Months Ended
	Mar. 31, 2015USD ($)ft²	Oct. 31, 2013Lawsuits	Nov. 30, 2013Lawsuits	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)Lawsuits	Dec. 31, 2013USD ($)
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				$ 129,727	$ 90,163	$ 69,930
Number of lawsuits filed | Lawsuits		3	3
Number of lawsuits dismissed | Lawsuits					2
Date of dismissal of lawsuits					Jan. 3, 2014
Number of days granted to plaintiffs to file an amended complaint				20 days
Settlement liability agreement date				April 16, 2015
Settlement amount				$ (3,500,000)

Agreements - Northwestern Unive

Agreements - Northwestern University - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
License Agreement [Line Items]
Accrued license fees	$ 52,500	$ 115,000
Northwestern License Agreement [Member]
License Agreement [Line Items]
License fee paid	406,590
Accrued license fees	52,500	$ 115,000
Future milestone payment	$ 300,000

Agreements - Biomarin - Additio

Agreements - Biomarin - Additional Information (Detail) - License Agreement with BioMarin [Member] - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	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	$ 3,100,000
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 ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Consulting Agreements [Member]
Related Party Transaction [Line Items]
Consulting fees to Company officer and members of the Scientific Advisory Board	$ 55,000	$ 10,000	$ 10,000
CEO Employment Agreement [Member]
Related Party Transaction [Line Items]
Annual base salary of CEO	$ 471,000
Expiration date of employment agreement	2016-11
CEO potential performance based bonus compensation as a percentage of base salary	50.00%

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Deferred tax assets	$ 34,309,000	$ 24,895,000
Net operating loss carryforward and start-up costs	$ 28,682,000	$ 22,898,000
Valuation allowance	100.00%	100.00%
Change in valuation allowance	$ 9,414,000	$ 5,508,000	$ 3,796,000
Net operating loss carryforwards	$ 49,922,000
Net operating loss carryforwards expiration date	Beginning in 2023 and ending in 2035
Effective tax rate	0.00%
Statutory rate	35.00%

Stockholders' Equity (Preferred

Stockholders' Equity (Preferred Stock and Common Stock) - Additional Information (Detail) - $ / shares	Dec. 31, 2015	Dec. 31, 2014
Equity [Abstract]
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares outstanding	0	0
Common stock, shares authorized	150,000,000	100,000,000
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares issued	82,850,619	69,119,092
Common stock, shares outstanding	82,850,619	69,119,092

Stockholders' Equity (2014 Shel

Stockholders' Equity (2014 Shelf Registration Statement) - Additional Information (Detail) - 2014 Shelf Registration Statement [Member] - USD ($)	Feb. 04, 2015	Apr. 03, 2014	Dec. 31, 2015	Jan. 31, 2014
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
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%
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 (Warrant E

Stockholders' Equity (Warrant Exercises) - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Equity [Abstract]
Issuance of common stock for warrant exercises	1,178,261	1,262,296	3,862,250
Proceeds from exercise of warrants	$ 1,895,738	$ 1,316,503	$ 4,083,300

Stockholders' Equity (Stockhold

Stockholders' Equity (Stockholder Rights Plan) - Additional Information (Detail) - Stockholder Rights Plan [Member]	Sep. 20, 2011$ / shares
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

Stock Compensation Plans - Addi

Stock Compensation Plans - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option contractual term	2 years 11 months 5 days
Number of stock options exercised	1,249,608
Proceeds from exercise of options	$ 390,351	$ 522,000	$ 23,500
Stock options granted	1,760,000
Expected dividend rate	0.00%	0.00%	0.00%
Options to Purchase Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of stock options exercised	265,000	580,000	50,000
Proceeds from exercise of options	$ 390,351	$ 522,000	$ 23,500
Number of stock options exercised cashless	984,608	185,000
Shares issued for cashless option exercise	761,600	119,709
Non-cash stock-based compensation expense	$ 1,510,018	$ 767,838	$ 175,855
Stock option granted, contractual term	7 years		5 years
Stock options granted	1,760,000	1,305,000	115,000
Unrecognized compensation expense related to non-vested stock option awards granted under the Plan	$ 4,290,447
Expected remaining weighted average vesting period	2 years 3 months 18 days
Expected dividend rate	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	4,000,000
Common stock shares available for future issuance under the Plan	1,050,000
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Non-cash stock-based compensation expense	$ 75,440	$ 10,131	$ 0
Minimum [Member] | Options to Purchase Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option granted, contractual term		5 years
Minimum [Member] | Restricted Stock Units (RSUs) [Member] | Two Thousand Fourteen Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share based compensation, vesting period	3 years
Minimum [Member] | Stock Options [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
Maximum [Member] | Options to Purchase Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option granted, contractual term		7 years
Maximum [Member] | Restricted Stock Units (RSUs) [Member] | Two Thousand Fourteen Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share based compensation, vesting period	4 years
Maximum [Member] | Stock Options [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

Stock Compensation Plans - Summ

Stock Compensation Plans - Summary of Stock Option Activity under the Company's Plan (Detail)	12 Months Ended
	Dec. 31, 2015USD ($)$ / sharesshares
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Number of options, Outstanding at beginning of year | shares	3,884,610
Number of options, Granted | shares	1,760,000
Number of options, Exercised | shares	(1,249,608)
Number of options, Forfeited or cancelled | shares	(145,002)
Number of options, Expired | shares	0
Number of options, Outstanding at end of year | shares	4,250,000
Number of options, Exercisable at end of year | shares	2,036,663
Weighted average exercise price, Outstanding at beginning of year | $ / shares	$ 1.50
Weighted average exercise price, Granted | $ / shares	3.02
Weighted average exercise price, Exercised | $ / shares	0.95
Weighted average exercise price, Forfeited or cancelled | $ / shares	3.30
Weighted average exercise price, Expired | $ / shares	0
Weighted average exercise price, Outstanding at end of year | $ / shares	2.23
Weighted average exercise price, Exercisable at end of year | $ / shares	$ 1.38
Weighted Average Remaining Contractual Term (Years), Outstanding at end of year	4 years 9 months
Weighted Average Remaining Contractual Term (Years), Exercisable at end of year	2 years 11 months 5 days
Aggregate Intrinsic value, Outstanding at end of year | $	$ 2,589,800
Aggregate Intrinsic value, Exercisable at end of year | $	$ 2,517,634

Stock Compensation Plans - Sche

Stock Compensation Plans - Schedule of Other Information Pertaining to Stock Option Activity (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Weighted average fair value of granted stock options	$ 2.13	$ 2.41	$ 0.48
Total fair value of vested stock options	$ 1,307,895	$ 409,476	$ 166,633
Total intrinsic value of exercised stock options	$ 3,311,599	$ 1,339,100	$ 17,975

Stock Compensation Plans - Su57

Stock Compensation Plans - Summary of Company's Stock Options Outstanding (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
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	$ 3.12	$ 6
Number Outstanding, Options Outstanding	4,250,000
Weighted Average Remaining Contractual Life (Years), Options Outstanding	4 years 9 months
Weighted Average Exercise Price, Options Outstanding	$ 2.23
Number Exercisable Options Exercisable	2,036,663
Weighted Average Remaining Contractual Life (Years), Options Exercisable	2 years 11 months 5 days
Weighted Average Exercise Price, Options Exercisable	$ 1.38
$0.47 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of Exercise Prices	$ 0.47
Number Outstanding, Options Outstanding	950,000
Weighted Average Remaining Contractual Life (Years), Options Outstanding	1 year 11 months 19 days
Weighted Average Exercise Price, Options Outstanding	$ 0.47
Number Exercisable Options Exercisable	925,000
Weighted Average Remaining Contractual Life (Years), Options Exercisable	1 year 11 months 16 days
Weighted Average Exercise Price, Options Exercisable	$ 0.47
$0.85 to $2.35 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of Exercise Prices Lower Range	0.85
Range of Exercise Prices Upper Range	$ 2.35
Number Outstanding, Options Outstanding	535,000
Weighted Average Remaining Contractual Life (Years), Options Outstanding	1 year 2 months 12 days
Weighted Average Exercise Price, Options Outstanding	$ 1.13
Number Exercisable Options Exercisable	508,333
Weighted Average Remaining Contractual Life (Years), Options Exercisable	1 year 1 month 10 days
Weighted Average Exercise Price, Options Exercisable	$ 1.10
$2.53 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of Exercise Prices	$ 2.53
Number Outstanding, Options Outstanding	1,140,000
Weighted Average Remaining Contractual Life (Years), Options Outstanding	7 years
Weighted Average Exercise Price, Options Outstanding	$ 2.53
Number Exercisable Options Exercisable	120,000
Weighted Average Remaining Contractual Life (Years), Options Exercisable	7 years
Weighted Average Exercise Price, Options Exercisable	$ 2.53
$2.62 to $3.12 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of Exercise Prices Lower Range	2.62
Range of Exercise Prices Upper Range	$ 3.12
Number Outstanding, Options Outstanding	1,060,000
Weighted Average Remaining Contractual Life (Years), Options Outstanding	5 years 8 months 9 days
Weighted Average Exercise Price, Options Outstanding	$ 3.10
Number Exercisable Options Exercisable	483,330
Weighted Average Remaining Contractual Life (Years), Options Exercisable	5 years 7 months 28 days
Weighted Average Exercise Price, Options Exercisable	$ 3.12
$3.34 to $4.64 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of Exercise Prices Lower Range	3.34
Range of Exercise Prices Upper Range	$ 4.64
Number Outstanding, Options Outstanding	565,000
Weighted Average Remaining Contractual Life (Years), Options Outstanding	6 years 5 months 19 days
Weighted Average Exercise Price, Options Outstanding	$ 3.97
Number Exercisable Options Exercisable	0
Weighted Average Remaining Contractual Life (Years), Options Exercisable	0 years
Weighted Average Exercise Price, Options Exercisable	$ 0

Stock Compensation Plans - Su58

Stock Compensation Plans - Summary of Stock Options Awards Based on Certain Assumptions (Detail)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk free interest rate, Minimum	1.00%	1.18%	0.45%
Risk free interest rate, Maximum	2.13%	2.03%	0.53%
Expected term			3 years
Expected volatility	102.00%	115.00%	137.00%
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	3 years	3 years
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term	7 years	7 years

Stock Compensation Plans - Su59

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

Benefit Plan - Additional Infor

Benefit Plan - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
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	$ 69,000	$ 44,000	$ 30,000

Quarterly Financial Informati61

Quarterly Financial Information (Unaudited) - Schedule of Quarterly Financial Information (Detail) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Quarterly Financial Information Disclosure [Abstract]
Revenues	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0
Loss from operations	(6,191,679)	(5,017,428)	(4,897,330)	(4,291,915)	(3,983,861)	(4,109,029)	(2,990,173)	(3,508,365)	(20,398,352)	(14,591,428)	(10,311,658)
Change in fair value of warrants liability	389,596	521,731	333,956	(1,180,278)	472,026	(906,787)	(223,591)	(335,514)	65,005	(993,866)	(1,890,359)
Net loss	$ (5,815,158)	$ (4,449,038)	$ (4,558,503)	$ (5,410,259)	$ (3,490,030)	$ (5,009,892)	$ (3,198,020)	$ (3,811,119)	$ (20,232,958)	$ (15,509,061)	$ (12,154,596)
Loss per share - basic and diluted	$ (0.07)	$ (0.05)	$ (0.06)	$ (0.07)	$ (0.05)	$ (0.07)	$ (0.05)	$ (0.07)	$ (0.25)	$ (0.24)	$ (0.27)