Catalyst Pharmaceuticals (CPRX) 10-K 16 Mar 20 2019 FY Annual report Financial data

Cover Page

Cover Page - USD ($)	12 Months Ended
	Dec. 31, 2019	Mar. 12, 2020	Jun. 30, 2019
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Entity Registrant Name	CATALYST PHARMACEUTICALS, INC.
Entity Central Index Key	0001369568
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity Filer Category	Accelerated Filer
Trading Symbol	CPRX
Entity Emerging Growth Company	false
Entity Small Business	true
Entity Address, State or Province	FL
Entity Interactive Data Current	Yes
Title of 12(b) Security	Common Stock
Security Exchange Name	NASDAQ
Entity Common Stock, Shares Outstanding		103,408,699
Entity Public Float			$ 367,949,157

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Current Assets:
Cash and cash equivalents	$ 89,511,710	$ 16,559,400
Short-term investments	5,007,050	36,922,213
Accounts receivable, net	10,536,997
Inventory	1,956,792	56,012
Prepaid expenses and other current assets	4,351,074	1,649,781
Total current assets	111,363,623	55,187,406
Investments	0	5,008,243
Operating lease right-of-use asset	793,252
Property and equipment, net	210,467	245,425
Deposits	8,888	8,888
Total assets	112,376,230	60,449,962
Current Liabilities:
Accounts payable	4,117,447	2,337,367
Accrued expenses and other liabilities	19,981,295	7,173,987
Total current liabilities	24,098,742	9,511,354
Accrued expenses and other liabilities, non-current	0	154,799
Operating lease liability, net of current portion	647,532
Total liabilities	24,746,274	9,666,153
Commitments and contingencies
Stockholders' equity:
Preferred stock, $0.001 par value, 5,000,000 shares authorized: none issued and outstanding at December 31, 2019 and 2018	0
Common stock, $0.001 par value, 150,000,000 shares authorized; 103,397,033 shares and 102,739,257 shares issued and outstanding at December 31, 2019 and 2018, respectively	103,397	102,739
Additional paid-in capital	216,205,678	211,265,279
Accumulated deficit	(128,688,624)	(160,563,961)
Accumulated other comprehensive income (loss)	9,505	(20,248)
Total stockholders' equity	87,629,956	50,783,809
Total liabilities and stockholders' equity	$ 112,376,230	$ 60,449,962

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2019	Dec. 31, 2018
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	103,397,033	102,739,257
Common stock, shares outstanding	103,397,033	102,739,257

Consolidated Statements of Oper

Consolidated Statements of Operations and Comprehensive Income (Loss) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Revenues:
Revenues	$ 102,306,337
Revenues		$ 500,000
Operating costs and expenses:
Cost of sales	14,759,139
Research and development	18,842,752	19,919,204
Selling, general and administrative	36,881,187	15,875,961
Total operating costs and expenses	70,483,078	35,795,165
Other income, net	1,585,774	1,291,651
Operating income (loss)	31,823,259	(35,295,165)
Net income (loss) before income taxes	33,409,033	(34,003,514)
Provision for income taxes	1,533,696
Net income (loss)	$ 31,875,337	$ (34,003,514)
Net income (loss) per share:
Basic	$ 0.31	$ (0.33)
Diluted	$ 0.30	$ (0.33)
Weighted average shares outstanding:
Basic	102,944,316	102,633,884
Diluted	106,020,936	102,633,884
Net income (loss)	$ 31,875,337	$ (34,003,514)
Other comprehensive income (loss):
Unrealized gain (loss) on available-for-sale securities	29,753	(20,248)
Comprehensive income (loss)	31,905,090	(34,023,762)
Product [Member]
Revenues:
Revenues	102,306,337
Collaborative Arrangement Product Agreement [Member]
Revenues:
Revenues	$ 0
Revenues		$ 500,000

Consolidated Statement of Chang

Consolidated Statement of Changes in Stockholders' Equity - USD ($)	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Gain (Loss) [Member]
Beginning Balance at Dec. 31, 2017	$ 80,963,812	$ 102,549	$ 207,421,710	$ (126,560,447)
Issuance of common stock, net	10,549	3	10,546
Issuance of stock options for services	3,535,647		3,535,647
Exercise of stock options for common stock	297,563	187	297,376
Other comprehensive gain (loss)	(20,248)				$ (20,248)
Net income (loss)	(34,003,514)			(34,003,514)
Ending Balance at Dec. 31, 2018	50,783,809	102,739	211,265,279	(160,563,961)	(20,248)
Issuance of stock options for services	3,780,086		3,780,086
Exercise of stock options for common stock	1,116,242	658	1,115,584
Amortization of restricted stock for services	44,729		44,729
Other comprehensive gain (loss)	29,753				29,753
Net income (loss)	31,875,337			31,875,337
Ending Balance at Dec. 31, 2019	$ 87,629,956	$ 103,397	$ 216,205,678	$ (128,688,624)	$ 9,505

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Operating Activities:
Net income (loss)	$ 31,875,337	$ (34,003,514)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation	54,327	37,978
Amortization of right-of-use asset	243,399
Stock-based compensation	3,824,815	3,550,644
Change in accrued interest and accretion of discount on investments	(290,805)	(443,139)
(Increase) decrease in:
Accounts receivable, net	(10,536,997)
Inventory	(1,900,780)	(56,012)
Prepaid expenses and other current assets and deposits	(2,701,293)	(476,037)
Increase (decrease) in:
Accounts payable	1,780,080	391,792
Accrued expenses and other liabilities	12,540,197	4,850,743
Operating lease liability	(276,807)
Net cash provided by (used in) operating activities	34,611,473	(26,147,545)
Investing Activities:
Purchases of property and equipment	(19,369)	(92,018)
Purchases of investments	(34,725,401)	(36,790,854)
Proceeds from maturities and sales of investments	71,969,365	21,800,000
Net cash provided by (used in) investing activities	37,224,595	(15,082,872)
Financing Activities:
Payment of employee withholding tax related to stock-based compensation	0	(4,448)
Proceeds from exercise of stock options	1,116,242	297,563
Net cash provided by (used in) financing activities	1,116,242	293,115
Net increase (decrease) in cash and cash equivalents	72,952,310	(40,937,302)
Cash and cash equivalents - beginning of period	16,559,400	57,496,702
Cash and cash equivalents - end of period	89,511,710	16,559,400
Non-cash investing and financing activities:
Unrealized gain (loss) on available-for-sale securities	$ 29,753	$ (20,248)

Organization and Description of

Organization and Description of Business	12 Months Ended
	Dec. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Description of Business	1. Organization and Description of Business. Catalyst Pharmaceuticals, Inc. and subsidiary (collectively, the “Company”) is a biopharmaceutical company focused on developing and commercializing innovati ve On November 28, 2018, the U.S. Food and Drug Administration, or FDA, granted approval of Firdapse ® ® 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, raising capital, and selling its product. The Company incurred operating losses in each period from inception, and started reporting operating income during the year ended December 31, 2019. The Company has been able to fund its cash needs to date through several public and private offerings of its securities and from revenues from its product sales. See Note 11 (Stockholders’ Equity). Capital Resources 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 from the issuance date of this Form 10-K. 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 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, 2019
Accounting Policies [Abstract]
Basis of Presentation and Significant Accounting Policies	2. Basis of Presentation and Significant Accounting Policies. a. PRINCIPLES OF CONSOLIDATION , b. USE OF ESTIMATES. principles generally accepted in the U.S . (U.S. GAAP) requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Actual results could differ from those estimates. c. CASH AND CASH EQUIVALENTS. d. INVESTMENTS. Short-Term Bond Fund The short-term bond fund was a ity U.S. Treasuries U.S. Treasuries are classified as available-for-sale available-for-sale Available-for-sale non-current available-for-sale comprehensive income (loss) and and comprehensive income (loss). available-for-sale available-for-sale ( Investments). e. ACCOUNTS RECEIVABLE, NET. trade discounts , f. INVENTORY. Inventories are stated at the lower of cost or net realizable value with cost determined under the first-in-first-out (FIFO) cost method. Inventories consist of raw materials and supplies, work in process and finished goods. Costs to be capitalized as inventories primarily include third party manufacturing costs and other overhead costs. The Company began capitalizing inventories post FDA approval of Firdapse ® on November 28, 2018 as the related costs were expected to be recoverable through the commercialization of the product. Costs incurred prior to the FDA approval of Firdapse ® were recorded as research and development expenses in prior years’ consolidated statements of operations and comprehensive income (loss). If information becomes available that suggests that inventories may not be realizable, the Company may be required to expense a portion or all of the previously capitalized inventories. As of December 31, 2019 inventory consisted mainly of raw materials, work-in-process and finished goods. As of December 31, 2018, inventory consisted mainly of packaging and labeling costs. Products that have been approved by the FDA or other regulatory authorities, such as Firdapse ® ® The Company evaluates for potential excess inventory by analyzing current and future product demand relative to the remaining product shelf life. The Company builds demand forecasts by considering factors such as, but not limited to, overall market potential, market share, market acceptance, and patient usage. g. PREPAID EXPENSES AND OTHER CURRENT ASSETS. pre-clinical h. PROPERTY AND EQUIPMENT , NET . i. FAIR VALUE OF FINANCIAL INSTRUMENTS. j. 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 Assets/Liabilities (Level 1) Significant (Level 2) Significant Unobservable (Level 3) Cash and cash equivalents: Money market funds $ 23,963,617 $ 23,963,617 $ — $ — U.S. Treasuries $ 59,932,200 $ $ 59,932,200 $ Short-term investments : U.S. Treasuries $ 5,007,050 $ — $ 5,007,050 $ — Balances as of Quoted Prices in Assets/Liabilities Significant (Level 2) Significant (Level 3) Cash and cash equivalents: Money market funds $ 14,462,087 $ 14,462,087 $ — $ — Short-term investments: Short-term bond fund $ 26,541,349 $ 26,541,349 $ — $ — U.S. Treasuries $ 10,380,864 $ — $ 10,380,864 $ — Investments: U.S. Treasuries $ 5,008,243 $ — $ 5,008,243 $ — k OPERATING LEASES. right-of-use Operating lease ROU assets and operating lease liabilities are recognized based on the present value of the future minimum lease payments over the lease term at commencement date. As the Company’s leases do not provide an implicit rate, the Company uses its incremental borrowing rate based on the information available at commencement date in determining the present value of future payments. The operating lease ROU asset also includes any lease payments made and excludes lease incentives and initial direct costs incurred. The Company’s lease terms do not include options to extend or terminate the lease as it is not reasonably certain that it will exercise these options. Lease expense for minimum lease payments is recognized on a straight-line basis over the lease term. The Company has lease agreements with lease and non-lease l. REVENUE RECOGNITION. ® ® ® ® ® To determine revenue recognition for arrangements that are within the scope of Topic 606, the Company performs the following five steps: (i) identify the contract(s) with a customer, (ii) identify the performance obligations in the contract, (iii) determine the transaction price, (iv) allocate the transaction price to the performance obligations in the contract, and (v) recognize revenue when (or as) the entity satisfies a performance obligation. The Company only applies the five-step model to arrangements that meet the definition of a contract under Topic 606, including when it is probable that the Company will collect the consideration it is entitled to in exchange for the goods or services it transfers to the customer. At contract inception, once the contract is determined to be within the scope of Topic 606, the Company assesses the goods or services promised within each contract and determines those that are performance obligations and assesses whether each promised good or service is distinct. The Company then recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligation when (or as) the performance obligation is satisfied. For a complete discussion of accounting for product revenue, see Product Revenue, Net below. The Company also may Product Revenue, Net: ® the ® The Company recognizes revenue on product sales when the Customer obtains control of the Company’s product, which occurs at a point in time (upon delivery). Product revenue is recorded net of applicable reserves for variable consideration, including discounts and allowances. The Company’s payment terms range between 15 and 30 days. Shipping and handling costs for product shipments occur prior to the customer obtaining control of the goods, and are recorded in cost of sales. If taxes should be collected from the Customer relating to product sales and remitted to governmental authorities, they will be excluded from revenue. The Company expenses incremental costs of obtaining a contract when incurred, if the expected amortization period of the asset that the Company would have recognized is one year or less. However, no such costs were incurred during the year ended December 31, 2019. As of December 31, 2019, all of the Company’s sales are to its Customer. Reserves for Variable Consideration: The amount of variable consideration which is included in the transaction price may be constrained, and is included in the net sales price only to the extent that it is probable that a significant reversal in the amount of the cumulative revenue recognized under the contract will not occur in a future period. The Company’s analyses also contemplated application of the constraint in accordance with the guidance, under which it determined a material reversal of revenue would not occur in a future period for the estimates detailed below as of December 31, 2019 and, therefore, the transaction price was not reduced further during the year ended December 31, 2019. Actual amounts of consideration ultimately received may differ from the Company’s estimates. If actual results in the future vary from the Company’s estimates, the Company will adjust these estimates, which would affect net product revenue and earnings in the period such variances become known. Trade Discounts and Allowances: ® cons o Funded Co-pay co-pay commercially-insured co-pay ® C Product Returns: Provider Chargebacks and Discounts: , Government Rebates: Bridge and Patient Assistance Programs: ® pre-established ® ® ® ® , by applicable law Revenues from Collaborative Arrangement: ® the Nonrefundable upfront license fees are recognized upon receipt as persuasive evidence of an arrangement exists, the price to the collaborator is fixed or determinable and collectability is reasonably assured. The collaborative agreement provides for a milestone payment upon achievement of development and regulatory events . The Company accounts for milestone payments in accordance with the provisions of Accounting Standards Update (ASU) No. 2010-17, Revenue Recognition – Milestone Method (“Milestone Method of Accounting”) . The Company recognizes consideration that is contingent upon the achievement of a milestone in its entirety as revenue in the period in which the milestone is achieved only if the milestone is substantive in its entirety. A milestone is considered substantive when it meets all of the following criteria: 1. The consideration is commensurate with either the entity’s performance to achieve the milestone or the enhancement of the value of the delivered item(s) as a result of a specific outcome resulting from the entity’s performance to achieve the milestone; 2. The consideration relates solely to past performance; and 3. The consideration is reasonable relative to all of the deliverables and payment terms within the arrangement. A milestone is defined as an event (i) that can only be achieved based in whole or in part on either the entity’s performance or on the occurrence of a specific outcome resulting from the entity’s performance, (ii) for which there is substantive uncertainty at the date the arrangement is entered into that the event will be achieved, and (iii) that would result in additional payments being due to the vendor. The Company believes that achievement of the milestone will be substantive and there will be no substantive uncertainty once the milestone is achieved. Since the Company will receive royalty reports 60 days after quarter end, royalty revenue from sales of collaboration products by our collaborators will be recognized in the quarter following the quarter in which the corresponding sales occurred. As of December 31, 2019 and 2018, there was no royalty revenue from sales of the collaborative product. Refer to Note 7 ( ) m. RESEARCH AND DEVELOPMENT. , n. STOCK-BASED COMPENSATION o. CONCENTRATION OF RISK. The financial instruments that potentially subject the Company to concentration of credit risk are cash equivalents (i.e., money market funds), investments and accounts receivable, net. The Company places its cash and cash The Company sells its product in the United States through an exclusive distributor (its Customer) to specialty pharmacies. Therefore, its distributor and specialty pharmacies account for all of its trade receivables and net product revenues. The creditworthiness of its Customer is continuously monitored, and the Company has internal policies regarding customer credit limits. The Company estimates an allowance for doubtful accounts primarily based on the credit worthiness of its Customer, historical payment patterns, aging of receivable balances and general economic conditions. The Company currently has a single product with limited commercial sales experience, which makes it difficult to evaluate its current business, predict its future prospects and forecast financial performance and growth. The Company has invested a significant portion of its efforts and financial resources in the development and commercialization of the lead product, Firdapse ® ® ® The Company relies exclusively on third parties to formulate and manufacture Firdapse ® and its drug candidates. The commercialization of Firdapse ® and any other drug candidates, if approved, could be stopped, delayed or made less profitable if those third parties fail to provide sufficient quantities of product or fail to do so at acceptable quality levels or prices. The Company does not intend to establish its own manufacturing facilities. The Company is using the same third-party contractors to manufacture, supply, store and distribute drug supplies for clinical trials and for the commercialization of Firdapse ® . If the Company is unable to continue its relationships with one or more of these third-party contractors, it could experience delays in the development or commercialization efforts as it locates and qualifies new manufacturers. The Company intends to rely on one or more third-party contractors to manufacture the commercial supply of its drugs. p. ROYALTIES. with ( ) q. 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 2016 On December 22, 2017, the U.S. government enacted comprehensive tax legislation commonly referred to as the Tax Cuts and Jobs Act (the “Tax Act”). The Tax Act makes broad and complex changes to the U.S. tax code, including, but not limited to : one-time r. COMPREHENSIVE INCOME (LOSS). available-for-sale s. NET INCOME (LOSS) PER COMMON SHARE Diluted net income ( ) ( ) The following table reconciles basic and diluted weighted average common shares: For the Years Ended 2019 2018 Basic weighted average common shares outstanding 102,944,316 102,633,884 Effect of dilutive securities: Common stock issuable upon the exercise of stock options 3,076,620 — Diluted weighted average common shares outstanding 106,020,936 102,633,884 Outstanding common stock equivalents totaling approximately 4.6 million, were excluded from the calculation of diluted net income (loss) per common share for the year ended December 31, 2019 as their effect would be anti-dilutive. For the year ended December 31, 2018, approximately 10.5 million shares of outstanding stock options were excluded from the calculation of diluted net loss per common share because a net loss was reported in this period and therefore their effect was anti-dilutive. Potentially dilutive options to purchase common stock as of December 31, 2019 had exercise prices ranging from $0.79 to $4.20. Potentially dilutive options to purchase common stock as of December 31, 2018 had exercise prices ranging from $0.79 to $4.64. t. SEGMENT INFORMATION. u. RECLASSIFICATIONS. v. RECENTLY ISSUED ACCOUNTING STANDARDS. No. 2016-02, No. 2016-02 2016-02 right-of-use ( O L ases) In June 2018, the FASB issued ASU No. 2018-07, No. 2018-07 2018-07 In June 2016, the FASB issued ASU No. 2016-13, available-for-sale adopted The adoption of this standard did not have a material impact on the Company’s consolidated financial statements

Investments

Investments	12 Months Ended
	Dec. 31, 2019
Investments, Debt and Equity Securities [Abstract]
Investments	3. Investments. Available-for-sale Estimated Gross Gross Amortized At December 31, 2019: U.S. Treasuries - Cash equivalents $ 59,932,200 $ 2,042 $ — $ 59,930,158 U.S. Treasuries - S 5,007,050 7,463 — 4,999,587 Total $ 64,939,250 $ 9,505 $ — $ 64,929,745 At December 31, 2018: U.S. Treasuries - ST $ 10,380,864 $ — $ (1,835 ) $ 10,382,699 U.S. Treasuries - LT 5,008,243 — (18,413 ) 5,026,656 Total $ 15,389,107 $ — $ (20,248 ) $ 15,409,355 There were no realized gains or losses from available-for-sale The Company did not hold any securities in an unrealized loss position for more than 12 months as of December 31, 2019. The estimated fair values of available-for-sale 2019 Due in one year or less $ 64,939,250

Prepaid Expenses and Other Curr

Prepaid Expenses and Other Current Assets	12 Months Ended
	Dec. 31, 2019
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: 2019 2018 Prepaid manufacturing costs $ 1,526,013 $ — Prepaid insurance 1,263,129 800,261 Prepaid subscriptions fees 501,251 170,552 Prepaid research fees 481,057 358,209 Prepaid commercialization expenses 62,959 17,030 Other 516,665 303,729 Total prepaid expenses and other current assets $ 4,351,074 $ 1,649,781

Operating Leases

Operating Leases	12 Months Ended
	Dec. 31, 2019
Disclosure of Operating Leases [Abstract]
Operating Leases	5. Operating Leases. The Company has operating lease agreements for its corporate office. The leases include options to extend the leases for up to 1 year and options to terminate the lease within 1 year. There are no obligations under finance leases. The components of lease expense were as follows: For the Year Operating lease cost $ 296,316 Supplemental cash flow information related to leases was as follows: December 31, 2019 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows $ 329,725 Right-of-use Operating leases $ 21,220 Supplemental balance sheet information related to leases was as follows: December 31, 2019 Operating lease right-of-use $ 793,252 Other current liabilities $ 300,518 Operating lease liabilities, net of current portion 647,532 Total operating lease liabilities $ 948,050 Weighted average remaining lease term 2.9 years Weighted average discount rate 4.81 % Remaining payments of lease liabilities as of December 31, 2019 were as follows: 2020 $ 339,605 2021 349,788 2022 329,662 Total lease payments 1,019,055 Less imputed interest (71,005 ) Total $ 948,050 Rent expense was $242,155 for the year ended December 31, 2018.

Accrued Expenses and Other Liab

Accrued Expenses and Other Liabilities	12 Months Ended
	Dec. 31, 2019
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: 2019 2018 Accrued preclinical and clinical trial expenses $ 1,183,513 $ 821,633 Accrued professional fees 1,241,526 1,311,061 Accrued compensation and benefits 3,064,645 1,941,449 Accrued license fees 8,751,991 3,000,000 Accrued purchases 1,313,310 — Accrued contributions 1,535,000 — Operating lease liability 300,518 — Accrued variable consideration 884,764 — Deferred rent and lease incentive — Income tax payable 1,533,696 — Other 172,332 66,436 Current accrued expenses and other liabilities 19,981,295 7,173,987 Lease liability – non-current 647,532 — Deferred rent and lease incentive—non-current — 154,799 Non-current accrued expenses and other liabilities 647,532 154,799 Total accrued expenses and other liabilities $ 20,628,827 $ 7,328,786

Collaborative Arrangement

Collaborative Arrangement	12 Months Ended
	Dec. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Collaborative Arrangement	7. Collaborative Arrangement. In December 2018, the Company entered into a collaboration and license agreement ( C ® Under the Collaboration, Endo assumes all development, manufacturing, clinical, regulatory, sales and marketing costs under the collaboration, while the Company is responsible for exercising commercially reasonable efforts to develop, or cause the development of, a final finished, stable dosage form of generic Sabril ® Under the terms of the Collaboration, the Company has received an up-front a milestone payment, and a sharing of defined net profits upon commercialization from Endo consisting of a mid-double digit percent of net sales of generic Sabril ® . The Company has also agreed to a sharing of certain development expenses. Unless terminated earlier in accordance with its terms, the collaboration continues in effect until the date that is ten years following the commercial launch of the product. The collaborative agreement provides for a $2.0 million milestone payment on the commercial launch of the product by Par . As of December 31, 2019 and 2018, no milestone payments have been earned. Revenues from collaborative arrangement were $0 and $500,000 (for upfront license fees) for the years ended December 31, 2019 and 2018, respectively. Total expenses incurred, net, in connection with the collaboration agreement for the years ended December 31, 2019 and December 31, 2018 were $65,061 and $0, and have been included in research and development expenses in the accompanying consolidated statements of operations.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	8. Commitments and Contingencies. In 2018, the Company became aware that certain patents granted to Northwestern University (which patents have been licensed by Northwestern to a third party) for a new GABA aminotransferase inhibitor were developed from CPP-115, CPP-115 In May 2019, the FDA approved an NDA for Jacobus Pharmaceuticals for Ruzurgi ® (3,4-DAP), ® ® ® ® ® off-label The Company believes that the FDA’s approval of Ruzurgi ® ® ® Additionally, from time to time the Company may become involved in legal proceedings arising in the ordinary course of business. Except as set forth above, the Company believes that there is no other litigation pending at this time that could have, individually or in the aggregate, a material adverse effect on its results of operations, financial condition or cash flows.

Agreements

Agreements	12 Months Ended
	Dec. 31, 2019
Text Block [Abstract]
Agreements	9. Agreements. a. LICENSE AGREEMENT WITH BIOMARIN (FIRDAPSE ® ) ® the licensor for seven years from the first commercial sale of Firdapse ® ® On May 29, 2019, the Company entered into an amendment to its license agreement for Firdapse ® ® Subsequent to year-end, b. AGREEMENTS FOR DRUG MANUFACTURING, DEVELOPMENT, PRECLINICAL AND CLINICAL STUDIES.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Income Taxes	10. Income Taxes. Due to the Company’s historical operating losses and the inability to recognize any income tax benefit, there was no provision for income taxes in the preceding period presented in these financial statements. Commencing in 2019, the Company has recorded income taxes on their pretax income using an e ffective The income tax expense for the years ended December 31, 2019 and 2018 consist s 2019 2018 Current $ 1,533,696 $ — Deferred — — $ 1,533,696 $ — The reconciliation of income tax expense (benefit) computed at the statutory federal income tax rate of 21% to amounts included in the statements of operations is as follows: 2019 2018 Statutory rate 21.0 % 21.0 % State tax 6.5 % 4.2 % Valuation allowance (20.9 ) % (25.9 )% Federal rate change 0.0 % 0.0 % Tax credit (2.5 ) % 1.4 % Other 0.5 % (0.7 )% 4.6 % 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, 2019 and 2018 are as follows: 2019 2018 Net operating loss $ 10,645,128 $ 19,867,591 Start-up s 12,894,926 13,861,147 Tax credits 14,320,860 12,625,275 Deferred compensation 3,183,767 1,919,434 Inventory 229,050 — Other 355,023 109,779 Gross deferred tax asset 41,628,754 48,383,226 Valuation allowance (41,628,754 ) (48,383,226 ) Net deferred tax assets $ — $ — The Company has evaluated the positive and negative evidence bearing upon the realizability of its deferred tax assets. As of December 31, 2019, and December 31, 2018, based on the Company’s history of operating losses, the Company has concluded that it is more likely than not that the benefit of its deferred tax assets will not be realized. Accordingly, the Company has provided a full valuation allowance for deferred tax assets including NOL and tax credit carryover as of December 31, 2019 and December 31, 2018. The valuation allowance decreased by $6.8 million and increased by million during 2019 and 2018, respectively. At December 31, 2019 and 2018, respectively, the Company had net operating loss carryforwards and other credits of approximately $41.5 million and $79.0 million available to reduce future taxable income, if any. The net operating loss carryforwards will expire at various dates beginning in 20 24 of 80% of 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. The tax credit carryforwards will expire at various dates beginning in 2032 and ending in 2040. Utilization of certain of the Company’s NOL and tax credit carryforwards in the United States is subject to annual limitation due to the ownership change limitations provided by Sections 382 and 383 of the Internal Revenue Code and similar state provisions. Such an annual limitation may result in the expiration of certain NOLs and tax credits before future utilization. The Company is currently conducting a study of the availability for use of its net operating loss carryforwards and other credits under Section 382 of the Internal Revenue Code. The results of this study could impact the amounts of net operating losses and other credits that the Company has available for use in future periods and the timing of their use. No interest or penalties were accrued through December 31, 201 9 2016. However, authorities can examine net operating loss carryforwards incurred prior to 2016 to the extent utilized in subsequent periods with open statutes. The Company is not currently under income tax examinations by any tax authorities.

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2019
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 , Common Stock The Company has 150,000,000 shares of authorized common stock, par value $0.001 per share. At December 31, 2019 and 2018, 103,397,033 and 102,739,257 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. 2016 Shelf Registration Statement On December 23, 2016, the Company filed a shelf Registration Statement on Form S-3 No. 333-215315) On January 9, 2020, the 2016 Shelf Registration Statement expired. 2017 Shelf Registration Statement On July 12, 2017, the Company filed a universal shelf Registration Statement on Form S-3 No. 333-219259) On November 28, 2017, the Company filed a prospectus supplement and offered for sale 16,428,572 shares of its common stock at a price of $3.50 per share in an underwritten public offering under the 2017 Shelf Registration. The Company received gross proceeds in the public offering of approximately $57.5 million before underwriting commission and incurred expenses of approximately $3.7 million. At December 31, 2019, there is approximately $92.5 million available for future sale under the 2017 Shelf Registration Statement. Stockholder Rights Plan On September 20, 2011, the Board of Directors approved the Company’s adoption of a Stockholder Rights Plan. Under the Stockholders’ Rights 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 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. On August 28, 2019, the Board of Directors unanimously adopted Amendment No. 2 to the Stockholders’ Rights Plan extending the outside expiration date of the rights plan to September 20, 2022.

Stock Compensation

Stock Compensation	12 Months Ended
	Dec. 31, 2019
Share-based Payment Arrangement [Abstract]
Stock Compensation	12. Stock Compensation. For the years ended December 31, 2019 and 2018, the Company recorded stock-based compensation expense as follows: 2019 2018 Research and development $ 1,137,596 $ 1,079,230 Selling, general and administrative 2,687,219 2,471,414 Total stock-based compensation $ 3,824,815 $ 3,550,644 The Company may issue stock options, restricted stock, stock appreciation rights and restricted stock units (collectively, the “Awards”) to employees, directors, and consultants of the Company under the 2014 and 2018 Stock Incentive Plans (the 2014 Plan and the 2018 Plan or collectively, the Plans). At December 31, 2019, no shares remain available for future issuance under the 2014 Plan. Under the 2018 Plan, 7,500,000 shares were reserved for issuance and as of December 31, 2019, 1,596,271 shares remain available for future issuance. Stock Options The Company has granted stock options to employees, officers, directors, 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 5 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, 2019 and 2018, options to purchase 654,332 and 186,665 shares of the Company’s common stock were exercised with gross proceeds to the Company of $1,116,242 and $297,563, respectively. Further, during the year ended December 31, 2019, options to purchase 6,666 shares of the Company’s common stock were exercised on a “cashless” basis, resulting in the issuance of an aggregate of 3,444 shares of the Company’s common stock, respectively. During the year ended December 31, 2018, no options to purchase shares of the Company’s common stock were exercised on a “cashless” basis. During the years ended December 31, 2019 and 2018 the Company recorded non-cash During the years ended December 31, 2019 and 2018, the Company granted seven-year options to purchase an aggregate of 2,183,500 and 5,882,500 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, 2019 is summarized as follows: Number of Weighted Weighted Aggregate Outstanding at beginning of year 10,532,500 $ 2.54 Granted 2,183,500 4.54 Exercised or released (660,998 ) 1.72 Forfeited or cancelled (511,668 ) 2.73 Expired (65,000 ) 3.90 Outstanding at end of year 11,478,334 $ 2.95 4.89 $ 11,590,899 Exercisable at end of year 5,844,819 $ 2.41 3.87 $ 8,084,671 Other information pertaining to stock option activity during the years ended December 31, 2019 and 2018 was as follows: 2019 2018 Weighted–average fair value of granted stock options $ 2.69 $ 1.93 Total fair value of vested stock options $ 3,864,995 $ 2,193,294 Total intrinsic value of exercised stock options $ 1,899,862 $ 274,864 The following table summarizes information about the Company’s options outstanding at December 31, 2019: Options Outstanding Options Exercisable Range of Exercise Prices Number Weighted Weighted Number Weighted Weighted $0.79 to $2.17 2,139,000 3.83 $ 1.05 1,757,332 3.73 $ 1.01 $2.18 to $2.43 2,350,000 5.97 $ 2.25 983,324 5.97 $ 2.24 $2.44 to $3.38 2,345,334 3.07 $ 2.88 1,919,996 2.46 $ 2.86 $3.39 to $4.07 2,592,500 5.17 $ 3.82 1,019,167 5.11 $ 3.85 $4.08 to $6.63 2,051,500 6.54 $ 4.74 165,000 2.48 $ 4.18 11,478,334 4.89 $ 2.95 5,844,819 3.87 $ 2.41 As of December 31, 2019, there was approximately $9.9 million 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: December 31, December 31, Risk free interest rate 1.51% to 2.53 % 2.09% to 2.88 % Expected term 4.5 years 0 to 7 years Expected volatility 75.5 % 82 % Expected dividend yield — % — % Expected forfeiture rate — % — % Restricted Stock Units Under the 2018 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-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 2019 was as follows: 2019 Number of Restricted Weighted Average Nonvested balance at beginning of year — $ — Granted 352,500 4.64 Vested — — Forfeited — — Nonvested balance at end of year 352,500 $ 4.64 No restricted stock units were granted or outstanding During the year ended December 31, 2019, the Company recorded non-cash Common Stock No shares of common stock were granted during the year ended December 31, 2019. During the year ended December 31, 2018, the Company granted 3,094 net shares of common stock to an employee as compensation. The Company recorded stock-based compensation related to common stock issued to an employee totaling approximately $15,000, during the year ended December 31, 2018.

Benefit Plan

Benefit Plan	12 Months Ended
	Dec. 31, 2019
Retirement Benefits [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, 2019
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, 2019 and 2018: Quarter Ended March 31, 2019 June 30, 2019 September 30, 2019 December 31, 2019 Revenues $ 12,448,438 $ 28,837,900 $ 30,897,444 $ 30,122,555 Income (loss) from operations $ (987,769 ) $ 10,959,189 $ 13,845,152 $ 8,006,687 Net income (loss) $ (644,503 ) $ 10,959,948 $ 13,630,179 $ 7,929,713 Net income (loss) per share – basic $ (0.01 ) $ 0.11 $ 0.13 $ 0.08 Net income (loss) per share – diluted $ (0.01 ) $ 0.10 $ 0.13 $ 0.07 Quarter Ended March 31, 2018 June 30, 2018 September 30, 2018 December 31, 2018 Revenues $ — $ — $ — $ 500,000 Loss from operations $ (5,933,440 ) $ (6,335,855 ) $ (8,182,603 ) $ (14,843,267 ) Net loss $ (5,699,892 ) $ (5,965,140 ) $ (7,838,873 ) $ (14,499,609 ) Net loss per share – basic and diluted $ (0.06 ) $ (0.06 ) $ (0.08 ) $ (0.14 ) Quarterly basic and diluted net income (loss) per common share were computed independently for each quarter and do not necessarily total to the full year basic and diluted net income (loss) per common share.

Basis of Presentation and Sig_2

Basis of Presentation and Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
PRINCIPLES OF CONSOLIDATION.	a. PRINCIPLES OF CONSOLIDATION ,
USE OF ESTIMATES	b. USE OF ESTIMATES. principles generally accepted in the U.S . (U.S. GAAP) requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Actual results could differ from those estimates.
CASH AND CASH EQUIVALENTS	c. CASH AND CASH EQUIVALENTS.
INVESTMENTS	d. INVESTMENTS. Short-Term Bond Fund The short-term bond fund was a ity U.S. Treasuries U.S. Treasuries are classified as available-for-sale available-for-sale Available-for-sale non-current available-for-sale comprehensive income (loss) and and comprehensive income (loss). available-for-sale available-for-sale ( Investments).
ACCOUNTS RECEIVABLE, NET	e. ACCOUNTS RECEIVABLE, NET. trade discounts ,
INVENTORY	f. INVENTORY. Inventories are stated at the lower of cost or net realizable value with cost determined under the first-in-first-out (FIFO) cost method. Inventories consist of raw materials and supplies, work in process and finished goods. Costs to be capitalized as inventories primarily include third party manufacturing costs and other overhead costs. The Company began capitalizing inventories post FDA approval of Firdapse ® on November 28, 2018 as the related costs were expected to be recoverable through the commercialization of the product. Costs incurred prior to the FDA approval of Firdapse ® were recorded as research and development expenses in prior years’ consolidated statements of operations and comprehensive income (loss). If information becomes available that suggests that inventories may not be realizable, the Company may be required to expense a portion or all of the previously capitalized inventories. As of December 31, 2019 inventory consisted mainly of raw materials, work-in-process and finished goods. As of December 31, 2018, inventory consisted mainly of packaging and labeling costs. Products that have been approved by the FDA or other regulatory authorities, such as Firdapse ® ® The Company evaluates for potential excess inventory by analyzing current and future product demand relative to the remaining product shelf life. The Company builds demand forecasts by considering factors such as, but not limited to, overall market potential, market share, market acceptance, and patient usage.
PREPAID EXPENSES AND OTHER CURRENT ASSETS	g. PREPAID EXPENSES AND OTHER CURRENT ASSETS. pre-clinical
PROPERTY AND EQUIPMENT, NET	h. PROPERTY AND EQUIPMENT , NET .
FAIR VALUE OF FINANCIAL INSTRUMENTS	i. FAIR VALUE OF FINANCIAL INSTRUMENTS.
FAIR VALUE MEASUREMENTS	j. 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 Assets/Liabilities (Level 1) Significant (Level 2) Significant Unobservable (Level 3) Cash and cash equivalents: Money market funds $ 23,963,617 $ 23,963,617 $ — $ — U.S. Treasuries $ 59,932,200 $ $ 59,932,200 $ Short-term investments : U.S. Treasuries $ 5,007,050 $ — $ 5,007,050 $ — Balances as of Quoted Prices in Assets/Liabilities Significant (Level 2) Significant (Level 3) Cash and cash equivalents: Money market funds $ 14,462,087 $ 14,462,087 $ — $ — Short-term investments: Short-term bond fund $ 26,541,349 $ 26,541,349 $ — $ — U.S. Treasuries $ 10,380,864 $ — $ 10,380,864 $ — Investments: U.S. Treasuries $ 5,008,243 $ — $ 5,008,243 $ —
OPERATING LEASES	k OPERATING LEASES. right-of-use Operating lease ROU assets and operating lease liabilities are recognized based on the present value of the future minimum lease payments over the lease term at commencement date. As the Company’s leases do not provide an implicit rate, the Company uses its incremental borrowing rate based on the information available at commencement date in determining the present value of future payments. The operating lease ROU asset also includes any lease payments made and excludes lease incentives and initial direct costs incurred. The Company’s lease terms do not include options to extend or terminate the lease as it is not reasonably certain that it will exercise these options. Lease expense for minimum lease payments is recognized on a straight-line basis over the lease term. The Company has lease agreements with lease and non-lease
REVENUE RECOGNITION	l. REVENUE RECOGNITION. ® ® ® ® ® To determine revenue recognition for arrangements that are within the scope of Topic 606, the Company performs the following five steps: (i) identify the contract(s) with a customer, (ii) identify the performance obligations in the contract, (iii) determine the transaction price, (iv) allocate the transaction price to the performance obligations in the contract, and (v) recognize revenue when (or as) the entity satisfies a performance obligation. The Company only applies the five-step model to arrangements that meet the definition of a contract under Topic 606, including when it is probable that the Company will collect the consideration it is entitled to in exchange for the goods or services it transfers to the customer. At contract inception, once the contract is determined to be within the scope of Topic 606, the Company assesses the goods or services promised within each contract and determines those that are performance obligations and assesses whether each promised good or service is distinct. The Company then recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligation when (or as) the performance obligation is satisfied. For a complete discussion of accounting for product revenue, see Product Revenue, Net below. The Company also may Product Revenue, Net: ® the ® The Company recognizes revenue on product sales when the Customer obtains control of the Company’s product, which occurs at a point in time (upon delivery). Product revenue is recorded net of applicable reserves for variable consideration, including discounts and allowances. The Company’s payment terms range between 15 and 30 days. Shipping and handling costs for product shipments occur prior to the customer obtaining control of the goods, and are recorded in cost of sales. If taxes should be collected from the Customer relating to product sales and remitted to governmental authorities, they will be excluded from revenue. The Company expenses incremental costs of obtaining a contract when incurred, if the expected amortization period of the asset that the Company would have recognized is one year or less. However, no such costs were incurred during the year ended December 31, 2019. As of December 31, 2019, all of the Company’s sales are to its Customer. Reserves for Variable Consideration: The amount of variable consideration which is included in the transaction price may be constrained, and is included in the net sales price only to the extent that it is probable that a significant reversal in the amount of the cumulative revenue recognized under the contract will not occur in a future period. The Company’s analyses also contemplated application of the constraint in accordance with the guidance, under which it determined a material reversal of revenue would not occur in a future period for the estimates detailed below as of December 31, 2019 and, therefore, the transaction price was not reduced further during the year ended December 31, 2019. Actual amounts of consideration ultimately received may differ from the Company’s estimates. If actual results in the future vary from the Company’s estimates, the Company will adjust these estimates, which would affect net product revenue and earnings in the period such variances become known. Trade Discounts and Allowances: ® cons o Funded Co-pay co-pay commercially-insured co-pay ® C Product Returns: Provider Chargebacks and Discounts: , Government Rebates: Bridge and Patient Assistance Programs: ® pre-established ® ® ® ® , by applicable law Revenues from Collaborative Arrangement: ® the Nonrefundable upfront license fees are recognized upon receipt as persuasive evidence of an arrangement exists, the price to the collaborator is fixed or determinable and collectability is reasonably assured. The collaborative agreement provides for a milestone payment upon achievement of development and regulatory events . The Company accounts for milestone payments in accordance with the provisions of Accounting Standards Update (ASU) No. 2010-17, Revenue Recognition – Milestone Method (“Milestone Method of Accounting”) . The Company recognizes consideration that is contingent upon the achievement of a milestone in its entirety as revenue in the period in which the milestone is achieved only if the milestone is substantive in its entirety. A milestone is considered substantive when it meets all of the following criteria: 1. The consideration is commensurate with either the entity’s performance to achieve the milestone or the enhancement of the value of the delivered item(s) as a result of a specific outcome resulting from the entity’s performance to achieve the milestone; 2. The consideration relates solely to past performance; and 3. The consideration is reasonable relative to all of the deliverables and payment terms within the arrangement. A milestone is defined as an event (i) that can only be achieved based in whole or in part on either the entity’s performance or on the occurrence of a specific outcome resulting from the entity’s performance, (ii) for which there is substantive uncertainty at the date the arrangement is entered into that the event will be achieved, and (iii) that would result in additional payments being due to the vendor. The Company believes that achievement of the milestone will be substantive and there will be no substantive uncertainty once the milestone is achieved. Since the Company will receive royalty reports 60 days after quarter end, royalty revenue from sales of collaboration products by our collaborators will be recognized in the quarter following the quarter in which the corresponding sales occurred. As of December 31, 2019 and 2018, there was no royalty revenue from sales of the collaborative product. Refer to Note 7 ( )
RESEARCH AND DEVELOPMENT	m. RESEARCH AND DEVELOPMENT. ,
STOCK-BASED COMPENSATION	n. STOCK-BASED COMPENSATION
CONCENTRATION OF CREDIT RISK	o. CONCENTRATION OF RISK. The financial instruments that potentially subject the Company to concentration of credit risk are cash equivalents (i.e., money market funds), investments and accounts receivable, net. The Company places its cash and cash The Company sells its product in the United States through an exclusive distributor (its Customer) to specialty pharmacies. Therefore, its distributor and specialty pharmacies account for all of its trade receivables and net product revenues. The creditworthiness of its Customer is continuously monitored, and the Company has internal policies regarding customer credit limits. The Company estimates an allowance for doubtful accounts primarily based on the credit worthiness of its Customer, historical payment patterns, aging of receivable balances and general economic conditions. The Company currently has a single product with limited commercial sales experience, which makes it difficult to evaluate its current business, predict its future prospects and forecast financial performance and growth. The Company has invested a significant portion of its efforts and financial resources in the development and commercialization of the lead product, Firdapse ® ® ® The Company relies exclusively on third parties to formulate and manufacture Firdapse ® and its drug candidates. The commercialization of Firdapse ® and any other drug candidates, if approved, could be stopped, delayed or made less profitable if those third parties fail to provide sufficient quantities of product or fail to do so at acceptable quality levels or prices. The Company does not intend to establish its own manufacturing facilities. The Company is using the same third-party contractors to manufacture, supply, store and distribute drug supplies for clinical trials and for the commercialization of Firdapse ® . If the Company is unable to continue its relationships with one or more of these third-party contractors, it could experience delays in the development or commercialization efforts as it locates and qualifies new manufacturers. The Company intends to rely on one or more third-party contractors to manufacture the commercial supply of its drugs.
ROYALTIES	p. ROYALTIES. with ( )
INCOME TAXES	q. 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 2016 On December 22, 2017, the U.S. government enacted comprehensive tax legislation commonly referred to as the Tax Cuts and Jobs Act (the “Tax Act”). The Tax Act makes broad and complex changes to the U.S. tax code, including, but not limited to : one-time
COMPREHENSIVE INCOME (LOSS)	r. COMPREHENSIVE INCOME (LOSS). available-for-sale
NET INCOME (LOSS) PER COMMON SHARE	s. NET INCOME (LOSS) PER COMMON SHARE
SEGMENT INFORMATION	t. SEGMENT INFORMATION.
RECLASSIFICATIONS	u. RECLASSIFICATIONS.
RECENTLY ISSUED ACCOUNTING STANDARDS	v. RECENTLY ISSUED ACCOUNTING STANDARDS. No. 2016-02, No. 2016-02 2016-02 right-of-use ( O L ases)

Basis of Presentation and Sig_3

Basis of Presentation and Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Fair Value Measurement Specific to Assets or Liability	Fair Value Measurements at Reporting Date Using Balances as of Quoted Prices in Assets/Liabilities (Level 1) Significant (Level 2) Significant Unobservable (Level 3) Cash and cash equivalents: Money market funds $ 23,963,617 $ 23,963,617 $ — $ — U.S. Treasuries $ 59,932,200 $ $ 59,932,200 $ Short-term investments : U.S. Treasuries $ 5,007,050 $ — $ 5,007,050 $ — Balances as of Quoted Prices in Assets/Liabilities Significant (Level 2) Significant (Level 3) Cash and cash equivalents: Money market funds $ 14,462,087 $ 14,462,087 $ — $ — Short-term investments: Short-term bond fund $ 26,541,349 $ 26,541,349 $ — $ — U.S. Treasuries $ 10,380,864 $ — $ 10,380,864 $ — Investments: U.S. Treasuries $ 5,008,243 $ — $ 5,008,243 $ —
Basic and Dilutive Weighted Average Common Shares	The following table reconciles basic and diluted weighted average common shares: For the Years Ended 2019 2018 Basic weighted average common shares outstanding 102,944,316 102,633,884 Effect of dilutive securities: Common stock issuable upon the exercise of stock options 3,076,620 — Diluted weighted average common shares outstanding 106,020,936 102,633,884

Investments (Tables)

Investments (Tables)	12 Months Ended
	Dec. 31, 2019
Investments, Debt and Equity Securities [Abstract]
Summary of Available-for-Sale Investments by Security type	Available-for-sale Estimated Gross Gross Amortized At December 31, 2019: U.S. Treasuries - Cash equivalents $ 59,932,200 $ 2,042 $ — $ 59,930,158 U.S. Treasuries - S 5,007,050 7,463 — 4,999,587 Total $ 64,939,250 $ 9,505 $ — $ 64,929,745 At December 31, 2018: U.S. Treasuries - ST $ 10,380,864 $ — $ (1,835 ) $ 10,382,699 U.S. Treasuries - LT 5,008,243 — (18,413 ) 5,026,656 Total $ 15,389,107 $ — $ (20,248 ) $ 15,409,355
Estimated Fair Values of Available for Sale Securities	The estimated fair values of available-for-sale 2019 Due in one year or less $ 64,939,250

Prepaid Expenses and Other Cu_2

Prepaid Expenses and Other Current Assets (Tables)	12 Months Ended
	Dec. 31, 2019
Text Block [Abstract]
Prepaid expenses and other current assets	Prepaid expenses and other current assets consist of the following as of December 31: 2019 2018 Prepaid manufacturing costs $ 1,526,013 $ — Prepaid insurance 1,263,129 800,261 Prepaid subscriptions fees 501,251 170,552 Prepaid research fees 481,057 358,209 Prepaid commercialization expenses 62,959 17,030 Other 516,665 303,729 Total prepaid expenses and other current assets $ 4,351,074 $ 1,649,781

Operating Leases (Tables)

Operating Leases (Tables)	12 Months Ended
	Dec. 31, 2019
Disclosure of Operating Leases [Abstract]
Lease, Cost	The components of lease expense were as follows: For the Year Operating lease cost $ 296,316
Schedule of Supplemental Cash Flow Information Related To Lease	Supplemental cash flow information related to leases was as follows: December 31, 2019 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows $ 329,725 Right-of-use Operating leases $ 21,220
Schedule of Supplemental Balance Sheet related To Lease	Supplemental balance sheet information related to leases was as follows: December 31, 2019 Operating lease right-of-use $ 793,252 Other current liabilities $ 300,518 Operating lease liabilities, net of current portion 647,532 Total operating lease liabilities $ 948,050 Weighted average remaining lease term 2.9 years Weighted average discount rate 4.81 %
Lessee, Operating Lease, Liability, Maturity	Remaining payments of lease liabilities as of December 31, 2019 were as follows: 2020 $ 339,605 2021 349,788 2022 329,662 Total lease payments 1,019,055 Less imputed interest (71,005 ) Total $ 948,050

Accrued Expenses and Other Li_2

Accrued Expenses and Other Liabilities (Tables)	12 Months Ended
	Dec. 31, 2019
Payables and Accruals [Abstract]
Schedule of Accrued Expenses and Other Liabilities	Accrued expenses and other liabilities consist of the following as of December 31: 2019 2018 Accrued preclinical and clinical trial expenses $ 1,183,513 $ 821,633 Accrued professional fees 1,241,526 1,311,061 Accrued compensation and benefits 3,064,645 1,941,449 Accrued license fees 8,751,991 3,000,000 Accrued purchases 1,313,310 — Accrued contributions 1,535,000 — Operating lease liability 300,518 — Accrued variable consideration 884,764 — Deferred rent and lease incentive — Income tax payable 1,533,696 — Other 172,332 66,436 Current accrued expenses and other liabilities 19,981,295 7,173,987 Lease liability – non-current 647,532 — Deferred rent and lease incentive—non-current — 154,799 Non-current accrued expenses and other liabilities 647,532 154,799 Total accrued expenses and other liabilities $ 20,628,827 $ 7,328,786

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Schedule of income tax expense	The income tax expense for the years ended December 31, 2019 and 2018 consist s 2019 2018 Current $ 1,533,696 $ — Deferred — — $ 1,533,696 $ —
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 21% to amounts included in the statements of operations is as follows: 2019 2018 Statutory rate 21.0 % 21.0 % State tax 6.5 % 4.2 % Valuation allowance (20.9 ) % (25.9 )% Federal rate change 0.0 % 0.0 % Tax credit (2.5 ) % 1.4 % Other 0.5 % (0.7 )% 4.6 % 0.0 %
Components of deferred tax assets	Significant components of the Company’s deferred tax assets as of December 31, 2019 and 2018 are as follows: 2019 2018 Net operating loss $ 10,645,128 $ 19,867,591 Start-up s 12,894,926 13,861,147 Tax credits 14,320,860 12,625,275 Deferred compensation 3,183,767 1,919,434 Inventory 229,050 — Other 355,023 109,779 Gross deferred tax asset 41,628,754 48,383,226 Valuation allowance (41,628,754 ) (48,383,226 ) Net deferred tax assets $ — $ —

Stock Compensation (Tables)

Stock Compensation (Tables)	12 Months Ended
	Dec. 31, 2019
Share-based Payment Arrangement [Abstract]
Stock-Based Compensation Expense	For the years ended December 31, 2019 and 2018, the Company recorded stock-based compensation expense as follows: 2019 2018 Research and development $ 1,137,596 $ 1,079,230 Selling, general and administrative 2,687,219 2,471,414 Total stock-based compensation $ 3,824,815 $ 3,550,644
Stock option activity under the Company's Plans	Stock option activity under the Company’s Plans for the year ended December 31, 2019 is summarized as follows: Number of Weighted Weighted Aggregate Outstanding at beginning of year 10,532,500 $ 2.54 Granted 2,183,500 4.54 Exercised or released (660,998 ) 1.72 Forfeited or cancelled (511,668 ) 2.73 Expired (65,000 ) 3.90 Outstanding at end of year 11,478,334 $ 2.95 4.89 $ 11,590,899 Exercisable at end of year 5,844,819 $ 2.41 3.87 $ 8,084,671
Schedule of Other Information Pertaining to Stock Option Activity	Other information pertaining to stock option activity during the years ended December 31, 2019 and 2018 was as follows: 2019 2018 Weighted–average fair value of granted stock options $ 2.69 $ 1.93 Total fair value of vested stock options $ 3,864,995 $ 2,193,294 Total intrinsic value of exercised stock options $ 1,899,862 $ 274,864
Summary of Company's Stock Options Outstanding	The following table summarizes information about the Company’s options outstanding at December 31, 2019: Options Outstanding Options Exercisable Range of Exercise Prices Number Weighted Weighted Number Weighted Weighted $0.79 to $2.17 2,139,000 3.83 $ 1.05 1,757,332 3.73 $ 1.01 $2.18 to $2.43 2,350,000 5.97 $ 2.25 983,324 5.97 $ 2.24 $2.44 to $3.38 2,345,334 3.07 $ 2.88 1,919,996 2.46 $ 2.86 $3.39 to $4.07 2,592,500 5.17 $ 3.82 1,019,167 5.11 $ 3.85 $4.08 to $6.63 2,051,500 6.54 $ 4.74 165,000 2.48 $ 4.18 11,478,334 4.89 $ 2.95 5,844,819 3.87 $ 2.41
Summary of Stock Options Awards Based on Certain Assumptions	Assumptions used during the years were as follows: December 31, December 31, Risk free interest rate 1.51% to 2.53 % 2.09% to 2.88 % Expected term 4.5 years 0 to 7 years Expected volatility 75.5 % 82 % Expected dividend yield — % — % Expected forfeiture rate — % — %
Summary of Restricted Stock Unit Activity	Restricted stock unit activity during 2019 was as follows: 2019 Number of Restricted Weighted Average Nonvested balance at beginning of year — $ — Granted 352,500 4.64 Vested — — Forfeited — — Nonvested balance at end of year 352,500 $ 4.64

Quarterly Financial Informati_2

Quarterly Financial Information (unaudited) (Tables)	12 Months Ended
	Dec. 31, 2019
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, 2019 and 2018: Quarter Ended March 31, 2019 June 30, 2019 September 30, 2019 December 31, 2019 Revenues $ 12,448,438 $ 28,837,900 $ 30,897,444 $ 30,122,555 Income (loss) from operations $ (987,769 ) $ 10,959,189 $ 13,845,152 $ 8,006,687 Net income (loss) $ (644,503 ) $ 10,959,948 $ 13,630,179 $ 7,929,713 Net income (loss) per share – basic $ (0.01 ) $ 0.11 $ 0.13 $ 0.08 Net income (loss) per share – diluted $ (0.01 ) $ 0.10 $ 0.13 $ 0.07 Quarter Ended March 31, 2018 June 30, 2018 September 30, 2018 December 31, 2018 Revenues $ — $ — $ — $ 500,000 Loss from operations $ (5,933,440 ) $ (6,335,855 ) $ (8,182,603 ) $ (14,843,267 ) Net loss $ (5,699,892 ) $ (5,965,140 ) $ (7,838,873 ) $ (14,499,609 ) Net loss per share – basic and diluted $ (0.06 ) $ (0.06 ) $ (0.08 ) $ (0.14 )

Basis of Presentation and Sig_4

Basis of Presentation and Significant Accounting Policies - Additional Information (Detail) $ / shares in Units, shares in Millions	12 Months Ended
	Dec. 31, 2019USD ($)SecuritiesSegment$ / sharesshares	Dec. 31, 2018USD ($)$ / sharesshares
Summary Of Basis Of Presentation And Significant Accounting Policies [Line Items]
Maximum maturity period of cash and cash equivalent	three months
Minimum amortization period of compensation cost on straight line basis	1 year
Maximum Amortization Period Of Compensation Cost On Straight Line Basis	5 years
Stock option exercise price range, Minimum | $ / shares	$ 0.79	$ 0.79
Stock option exercise price range, Maximum | $ / shares	$ 4.20	$ 4.64
Lease Expiration Date	Nov. 30, 2022
Trading Securities, Realized Gain (Loss)	$ 80,045
Trading Securities Sales		$ 0
Potential equivalent common stock excluded | shares	4.6	10.5
Number of trading securities | Securities	0
Number of Reportable Segments | Segment	1
Statutory rate	21.00%	21.00%
Generic Equivalent Commercially Sold [Member]
Summary Of Basis Of Presentation And Significant Accounting Policies [Line Items]
Potential unearned milestone payment to be received	$ 2,000,000
Collaborative Arrangement Product Agreement [Member]
Summary Of Basis Of Presentation And Significant Accounting Policies [Line Items]
Upfront license fees	$ 0	$ 500,000
U.S. federal corporate tax rate [Member]
Summary Of Basis Of Presentation And Significant Accounting Policies [Line Items]
Statutory rate	21.00%
Furniture and Equipment [Member]
Summary Of Basis Of Presentation And Significant Accounting Policies [Line Items]
Useful life of assets	5 years
Other Income, Net [Member]
Summary Of Basis Of Presentation And Significant Accounting Policies [Line Items]
Unrealized gain(loss),trading securities	$ 0	$ (29,430)
Minimum [Member] | Computer Equipment [Member]
Summary Of Basis Of Presentation And Significant Accounting Policies [Line Items]
Useful life of assets	3 years
Minimum [Member] | Leasehold Improvements [Member]
Summary Of Basis Of Presentation And Significant Accounting Policies [Line Items]
Useful life of assets	4 years
Maximum [Member] | Computer Equipment [Member]
Summary Of Basis Of Presentation And Significant Accounting Policies [Line Items]
Useful life of assets	5 years
Maximum [Member] | Leasehold Improvements [Member]
Summary Of Basis Of Presentation And Significant Accounting Policies [Line Items]
Useful life of assets	7 years

Basis of Presentation and Sig_5

Basis of Presentation and Significant Accounting Policies - Fair Value Measurement Specific to Assets or Liability (Detail) - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	$ 0	$ 5,008,243
Short-Term Bond Fund [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments Fair Value Disclosure		26,541,349
U.S. Treasuries [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments Fair Value Disclosure	59,932,200	10,380,864
Investments	5,007,050	5,008,243
Money Market Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market funds	23,963,617	14,462,087
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Short-Term Bond Fund [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments Fair Value Disclosure		26,541,349
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	23,963,617	14,462,087
Significant Other Observable Inputs (Level 2) [Member] | U.S. Treasuries [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments Fair Value Disclosure	59,932,200	10,380,864
Investments	5,007,050	$ 5,008,243
Significant Other Observable Inputs (Level 2) [Member] | Money Market Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market funds	0
Significant Other Observable Inputs (Level 3) [Member] | Money Market Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market funds	$ 0

Basis of Presentation and Sig_6

Basis of Presentation and Significant Accounting Policies - Schedule Of Reconcile Basic And Dilutive Weighted Average Common Shares (Details) - shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Accounting Policies [Abstract]
Basic weighted average common shares outstanding	102,944,316	102,633,884
Effect of dilutive securities:
Common stock issuable upon the exercise of stock options	3,076,620
Diluted weighted average common shares outstanding	106,020,936	102,633,884

Investments - Additional Inform

Investments - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Realized gains losses from available for sale securities	$ 0	$ 0

Investment - Summary of Availab

Investment - Summary of Available-for-Sale Investments by Security type (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Net Investment Income [Line Items]
Amortized cost	$ 64,929,745	$ 15,409,355
Gross Unrealized Gains	9,505
Gross Unrealized Losses	0	(20,248)
Estimated Fair Value	64,939,250	15,389,107
U.S. Treasuries - ST [Member]
Net Investment Income [Line Items]
Amortized cost		10,382,699
Gross Unrealized Losses		(1,835)
Estimated Fair Value		10,380,864
U.S. Treasuries - LT [Member]
Net Investment Income [Line Items]
Amortized cost	4,999,587	5,026,656
Gross Unrealized Gains	7,463
Gross Unrealized Losses	0	(18,413)
Estimated Fair Value	5,007,050	$ 5,008,243
US Treasury Bond Securities Cash Equivalents [Member]
Net Investment Income [Line Items]
Amortized cost	59,930,158
Gross Unrealized Gains	2,042
Gross Unrealized Losses	0
Estimated Fair Value	$ 59,932,200

Investment - Estimated Fair Val

Investment - Estimated Fair Values of Available for Sale Securities (Detail) - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Estimated Fair Value	$ 64,939,250	$ 15,389,107

Prepaid Expenses and Other Cu_3

Prepaid Expenses and Other Current Assets - Prepaid Expenses and Other Current Assets (Detail) - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Prepaid manufacturing costs	$ 1,526,013
Prepaid insurance	1,263,129	$ 800,261
Prepaid subscriptions fees	501,251	170,552
Prepaid research fees	481,057	358,209
Prepaid commercialization expenses	62,959	17,030
Other	516,665	303,729
Total prepaid expenses and other current assets	$ 4,351,074	$ 1,649,781

Operating Leases - Operating Le

Operating Leases - Operating Leases (Detail)	12 Months Ended
	Dec. 31, 2019USD ($)
Disclosure of Operating Leases [Abstract]
Operating lease cost	$ 296,316

Operating Leases - Schedule of

Operating Leases - Schedule of Supplemental Cash Flow Information Related To Lease (Detail)	12 Months Ended
	Dec. 31, 2019USD ($)
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows	$ 329,725
Right-of-use assets obtained in exchange for lease obligations:
Operating leases	$ 21,220

Operating Leases -Schedule of S

Operating Leases -Schedule of Supplemental Balance Sheet related To Lease (Detail)	Dec. 31, 2019USD ($)
Disclosure of Operating Leases [Line Items]
Operating lease right-of-use assets	$ 793,252
Other current liabilities	300,518
Operating lease liabilities, net of current portion	647,532
Total operating lease liabilities	$ 948,050
Weighted average remaining lease term	2 years 10 months 24 days
Weighted average discount rate	4.81%

Operating Leases -Lessee, Opera

Operating Leases -Lessee, Operating Lease, Liability, Maturity (Detail)	Dec. 31, 2019USD ($)
Disclosure of Operating Leases [Line Items]
2020	$ 339,605
2021	349,788
2022	329,662
Total lease payments	1,019,055
Less imputed interest	(71,005)
Total	$ 948,050

Operating Leases - Additional

Operating Leases - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Disclosure of Operating Leases [Line Items]
Finance Lease Obligations	$ 0
Lessor, Operating Lease, Option to Extend	1 year
Lessor, Operating Lease, Option to Terminate	1 year
Rent expense		$ 242,155

Accrued Expenses and Other Li_3

Accrued Expenses and Other Liabilities - Schedule of Accrued Expenses and Other Liabilities (Detail) - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Payables and Accruals [Abstract]
Accrued preclinical and clinical trial expenses	$ 1,183,513	$ 821,633
Accrued professional fees	1,241,526	1,311,061
Accrued compensation and benefits	3,064,645	1,941,449
Accrued license fees	8,751,991	3,000,000
Accrued purchases	1,313,310
Accrued contributions	1,535,000
Operating lease liability	300,518
Accrued variable consideration	884,764
Deferred rent and lease incentive	0	33,408
Income tax payable	1,533,696
Other	172,332	66,436
Current accrued expenses and other liabilities	19,981,295	7,173,987
Lease liability - non-current	647,532
Deferred rent and lease incentive - non-current	0	154,799
Non-current accrued expenses and other liabilities	647,532	154,799
Total accrued expenses and other liabilities	$ 20,628,827	$ 7,328,786

Collaborative Arrangement - Add

Collaborative Arrangement - Additional Information (Detail) - USD ($)	3 Months Ended	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Collaborative Arrangement [Line Items]
Period of collaboration agreement		10 years
Upfront License Fee	$ 500,000		$ 500,000
Expenses In Connection With Collaborative Arrangement		$ 18,842,752	19,919,204
Collaborative Arrangement [Member]
Collaborative Arrangement [Line Items]
Milestone payments		2,000,000
Milestone payments income		0	0
Upfront License Fee		0	500,000
Expenses In Connection With Collaborative Arrangement		$ 65,061	$ 0

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail)	1 Months Ended
	May 21, 2019USD ($)
Settlement Agreement [Member] | Other Income [Member]
Commitments [Line Items]
Litigation Settlement Received	$ 100,000

Agreements - Additional Informa

Agreements - Additional Information (Detail) - License Agreement with BioMarin [Member] $ in Millions	12 Months Ended
	Dec. 31, 2019USD ($)
License Agreement [Line Items]
Date on which strategic collaboration is entered into	Oct. 26, 2012
Royalty agreement period	7 years
Net sales royalty threshold	$ 100
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%

Income Taxes - Schedule of inco

Income Taxes - Schedule of income tax expense (Detail)	12 Months Ended
	Dec. 31, 2019USD ($)
Income Tax Disclosure [Abstract]
Current	$ 1,533,696
Deferred	0
Total income tax expense	$ 1,533,696

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Increase (decrease) in valuation allowance on deferred tax assets	$ (6,800,000)	$ 9,200,000
Net operating loss carryforwards	$ 41,500,000	79,000,000
Net operating loss carryforwards expiration date	Beginning in 2024 and ending in 2037
Tax credit carryforwards expiration date	beginning in 2032 and ending in 2040
Percentage of limited utilization of taxable income per year	80.00%
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, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Statutory rate	21.00%	21.00%
State tax	6.50%	4.20%
Valuation allowance	(20.90%)	(25.90%)
Federal rate change	0.00%	0.00%
Tax credit	(2.50%)	1.40%
Other	0.50%	(0.70%)
Reconciliation of income tax expense (benefit)	4.60%	0.00%

Income Taxes - Components of De

Income Taxes - Components of Deferred Tax Assets (Detail) - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Components of Deferred Tax Assets [Abstract]
Net operating loss	$ 10,645,128	$ 19,867,591
Start-up costs	12,894,926	13,861,147
Tax credits	14,320,860	12,625,275
Deferred compensation	3,183,767	1,919,434
Inventory	229,050
Other	355,023	109,779
Gross deferred tax asset	41,628,754	48,383,226
Valuation allowance	(41,628,754)	(48,383,226)
Net deferred tax assets	$ 0	$ 0

Stockholders' Equity (Preferred

Stockholders' Equity (Preferred Stock and Common Stock) - Additional Information (Detail)	Dec. 31, 2019Vote$ / sharesshares	Dec. 31, 2018$ / sharesshares
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
Common stock, par value | $ / shares	$ 0.001	$ 0.001
Common stock, shares issued	103,397,033	102,739,257
Common stock, shares outstanding	103,397,033	102,739,257
Number of votes entitled for each share of common stock | Vote	1

Stockholders' Equity (2016 Shel

Stockholders' Equity (2016 Shelf Registration Statement) - Additional Information (Detail)	Dec. 23, 2016USD ($)
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

Stockholders' Equity (2017 Shel

Stockholders' Equity (2017 Shelf Registration Statement) - Additional Information (Detail) - USD ($)	Nov. 28, 2017	Dec. 31, 2019	Jul. 12, 2017
Underwritten Public Offering [Member]
Stockholders' Equity [Line Items]
Number of common stock sold in offering	16,428,572
Common stock issued, price per share	$ 3.50
Gross proceeds from issuance of common stock	$ 57,500,000
Offering expenses	$ 3,700,000
2017 Shelf Registration Statement [Member]
Stockholders' Equity [Line Items]
Maximum dollar amount of securities to be issued under shelf registration statement			$ 150,000,000
Value of common stock available for future sale		$ 92,500,000

Stockholders' Equity (Stockhold

Stockholders' Equity (Stockholder Rights Plan) - Additional Information (Detail) - $ / shares	Sep. 19, 2016	Sep. 20, 2011	Dec. 31, 2019
Series A Preferred Stock [Member]
Stockholders Equity [Line Items]
Preferred Stock Purchase 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 - Stock-Base

Stock Compensation - Stock-Based Compensation Expense (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation	$ 3,824,815	$ 3,550,644
Research and Development [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation	1,137,596	1,079,230
Selling, General and Administrative [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation	$ 2,687,219	$ 2,471,414

Stock Compensation - Additional

Stock Compensation - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of stock options exercised	660,998
Proceeds from exercise of stock options	$ 1,116,242	$ 297,563
Common stock unit granted	2,183,500
Stock option contractual term	3 years 10 months 13 days
Expected dividend rate	0.00%	0.00%
Employee [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock unit granted		3,094
Non-cash stock-based compensation expense		$ 15,000
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	5 years
Stock option contractual term	7 years
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Non-cash stock-based compensation expense	$ 44,729	$ 0
Two Thousand Eighteen 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	7,500,000
Common stock shares available for future issuance under the Plan	1,596,271
Two Thousand Eighteen Stock Incentive Plan [Member] | Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share based compensation, vesting period	3 years
2014 Stock Incentive Plan [Member] | Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock shares available for future issuance under the Plan	0
Options to Purchase Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of stock options exercised	654,332	186,665
Proceeds from exercise of stock options	$ 1,116,242	$ 297,563
Stock option granted, contractual term	7 years	7 years
Common stock unit granted	2,183,500	5,882,500
Unrecognized compensation expense related to non-vested stock compensation awards granted under the Plan	$ 9,900,000
Expected remaining weighted average vesting period	2 years 3 months 29 days
Non-cash stock-based compensation expense	$ 3,780,086	$ 3,535,647
Expected dividend rate	0.00%
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	6,666	0
Shares issued for cashless option exercise	3,444

Stock Compensation - Summary of

Stock Compensation - Summary of Stock Option Activity under the Company's Plan (Detail)	12 Months Ended
	Dec. 31, 2019USD ($)$ / sharesshares
Share-based Payment Arrangement [Abstract]
Number of options, Outstanding at beginning of year | shares	10,532,500
Number of options, Granted | shares	2,183,500
Number of options, Exercised or released | shares	(660,998)
Number of options, Forfeited or cancelled | shares	(511,668)
Number of options, Expired | shares	(65,000)
Number of options, Outstanding at end of year | shares	11,478,334
Number of options, Exercisable at end of year | shares	5,844,819
Weighted average exercise price, Outstanding at beginning of year | $ / shares	$ 2.54
Weighted average exercise price, Granted | $ / shares	4.54
Weighted average exercise price, Exercised or released | $ / shares	1.72
Weighted average exercise price, Forfeited or cancelled | $ / shares	2.73
Weighted average exercise price, Expired | $ / shares	3.90
Weighted average exercise price, Outstanding at end of year | $ / shares	2.95
Weighted average exercise price, Exercisable at end of year | $ / shares	$ 2.41
Weighted Average Remaining Contractual Term (Years), Outstanding at end of year	4 years 10 months 20 days
Weighted Average Remaining Contractual Term (Years), Exercisable at end of year	3 years 10 months 13 days
Aggregate Intrinsic value, Outstanding at end of year | $	$ 11,590,899
Aggregate Intrinsic value, Exercisable at end of year | $	$ 8,084,671

Stock Compensation - Schedule o

Stock Compensation - Schedule of Other Information Pertaining to Stock Option Activity (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Share-based Payment Arrangement [Abstract]
Weighted-average fair value of granted stock options	$ 2.69	$ 1.93
Total fair value of vested stock options	$ 3,864,995	$ 2,193,294
Total intrinsic value of exercised stock options	$ 1,899,862	$ 274,864

Stock Compensation - Summary _2

Stock Compensation - Summary of Company's Stock Options Outstanding (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of Exercise Prices Lower Range	$ 0.79	$ 0.79
Range of Exercise Prices Upper Range	$ 4.20	$ 4.64
Number Outstanding, Options Outstanding	11,478,334
Weighted Average Remaining Contractual Life (Years), Options Outstanding	4 years 10 months 20 days
Weighted Average Exercise Price, Options Outstanding	$ 2.95
Number Exercisable Options Exercisable	5,844,819
Weighted Average Remaining Contractual Life (Years), Options Exercisable	3 years 10 months 13 days
Weighted Average Exercise Price, Options Exercisable	$ 2.41
$0.79 to $2.17 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of Exercise Prices Lower Range	0.79
Range of Exercise Prices Upper Range	$ 2.17
Number Outstanding, Options Outstanding	2,139,000
Weighted Average Remaining Contractual Life (Years), Options Outstanding	3 years 9 months 29 days
Weighted Average Exercise Price, Options Outstanding	$ 1.05
Number Exercisable Options Exercisable	1,757,332
Weighted Average Remaining Contractual Life (Years), Options Exercisable	3 years 8 months 23 days
Weighted Average Exercise Price, Options Exercisable	$ 1.01
$2.18 to $2.43 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of Exercise Prices Lower Range	2.18
Range of Exercise Prices Upper Range	$ 2.43
Number Outstanding, Options Outstanding	2,350,000
Weighted Average Remaining Contractual Life (Years), Options Outstanding	5 years 11 months 19 days
Weighted Average Exercise Price, Options Outstanding	$ 2.25
Number Exercisable Options Exercisable	983,324
Weighted Average Remaining Contractual Life (Years), Options Exercisable	5 years 11 months 19 days
Weighted Average Exercise Price, Options Exercisable	$ 2.24
$2.44 to $3.38 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of Exercise Prices Lower Range	2.44
Range of Exercise Prices Upper Range	$ 3.38
Number Outstanding, Options Outstanding	2,345,334
Weighted Average Remaining Contractual Life (Years), Options Outstanding	3 years 25 days
Weighted Average Exercise Price, Options Outstanding	$ 2.88
Number Exercisable Options Exercisable	1,919,996
Weighted Average Remaining Contractual Life (Years), Options Exercisable	2 years 5 months 15 days
Weighted Average Exercise Price, Options Exercisable	$ 2.86
$3.39 to $4.07 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of Exercise Prices Lower Range	3.39
Range of Exercise Prices Upper Range	$ 4.07
Number Outstanding, Options Outstanding	2,592,500
Weighted Average Remaining Contractual Life (Years), Options Outstanding	5 years 2 months 1 day
Weighted Average Exercise Price, Options Outstanding	$ 3.82
Number Exercisable Options Exercisable	1,019,167
Weighted Average Remaining Contractual Life (Years), Options Exercisable	5 years 1 month 9 days
Weighted Average Exercise Price, Options Exercisable	$ 3.85
$4.08 to $6.63 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of Exercise Prices Lower Range	4.08
Range of Exercise Prices Upper Range	$ 6.63
Number Outstanding, Options Outstanding	2,051,500
Weighted Average Remaining Contractual Life (Years), Options Outstanding	6 years 6 months 14 days
Weighted Average Exercise Price, Options Outstanding	$ 4.74
Number Exercisable Options Exercisable	165,000
Weighted Average Remaining Contractual Life (Years), Options Exercisable	2 years 5 months 23 days
Weighted Average Exercise Price, Options Exercisable	$ 4.18

Stock Compensation - Summary _3

Stock Compensation - Summary of Stock Options Awards Based on Certain Assumptions (Detail)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk free interest rate, Minimum	1.51%	2.09%
Risk free interest rate, Maximum	2.53%	2.88%
Expected volatility	75.50%	82.00%
Expected dividend yield	0.00%	0.00%
Expected forfeiture rate	0.00%	0.00%
Expected term	4 years 6 months
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term		0 years
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term		7 years

Stock Compensation - Summary _4

Stock Compensation - Summary of Restricted Stock Unit Activity (Detail) - Restricted Stock Units (RSUs) [Member]	12 Months Ended
	Dec. 31, 2019$ / sharesshares
Schedule Of Restricted Stock Activity [Line Items]
Nonvested balance at beginning of year | shares	0
Granted | shares	352,500
Vested | shares	0
Forfeited | shares	0
Nonvested balance at end of year | shares	352,500
Nonvested Weighted Average Grant Date Fair Value balance at beginning of year | $ / shares	$ 0
Weighted Average Grant Date Fair Value, Granted | $ / shares	4.64
Weighted Average Grant Date Fair Value, Vested | $ / shares	0
Weighted Average Grant Date Fair Value, Forfeited | $ / shares	0
Nonvested Weighted Average Grant Date Fair Value balance at end of year | $ / shares	$ 4.64

Benefit Plan - Additional Infor

Benefit Plan - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Retirement Benefits [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	$ 268,000	$ 123,000

Quarterly Financial Informati_3

Quarterly Financial Information (Unaudited) - Schedule of Quarterly Financial Information (Detail) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Revenues	$ 30,122,555	$ 30,897,444	$ 28,837,900	$ 12,448,438					$ 102,306,337
Revenues					$ 500,000					$ 500,000
Income (Loss) from operations	8,006,687	13,845,152	10,959,189	(987,769)	(14,843,267)	$ (8,182,603)	$ (6,335,855)	$ (5,933,440)	31,823,259	(35,295,165)
Net income (loss)	$ 7,929,713	$ 13,630,179	$ 10,959,948	$ (644,503)	$ (14,499,609)	$ (7,838,873)	$ (5,965,140)	$ (5,699,892)	$ 31,875,337	$ (34,003,514)
Net income (loss) per share - basic	$ 0.08	$ 0.13	$ 0.11	$ (0.01)					$ 0.31	$ (0.33)
Net income (loss) per share – diluted	$ 0.07	$ 0.13	$ 0.10	$ (0.01)					$ 0.30	$ (0.33)
Net loss per share – basic and diluted					$ (0.14)	$ (0.08)	$ (0.06)	$ (0.06)