Catalyst Pharmaceuticals (CPRX) 10-K 15 Mar 21 2020 FY Annual report Financial data

Cover Page

Cover Page - USD ($)	12 Months Ended
	Dec. 31, 2020	Mar. 11, 2021	Jun. 30, 2020
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2020
Document Fiscal Year Focus	2020
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	false
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		103,824,973
Entity Tax Identification Number	76-0837053
Entity Incorporation, State or Country Code	DE
Entity Address, Address Line One	355 Alhambra Circle
Entity Address, Address Line Two	Suite 801
Entity Address, City or Town	Coral Gables
Entity Address, Postal Zip Code	33134
City Area Code	305
Local Phone Number	420-3200
Document Annual Report	true
Document Transition Report	false
Entity File Number	001-33057
Entity Public Float			$ 444,887,344
ICFR Auditor Attestation Flag	true

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Current Assets:
Cash and cash equivalents	$ 130,237,109	$ 89,511,710
Short-term investments	10,041,068	5,007,050
Accounts receivable, net	5,987,426	10,536,997
Inventory	4,650,600	1,956,792
Prepaid expenses and other current assets	8,327,771	4,351,074
Total current assets	159,243,974	111,363,623
Operating lease right-of-use asset		793,252
Property and equipment, net	129,800	210,467
Deferred tax assets	32,971,264
Deposits	8,888	8,888
Total assets	192,353,926	112,376,230
Current Liabilities:
Accounts payable	4,256,020	4,117,447
Accrued expenses and other liabilities	18,500,267	19,981,295
Total current liabilities	22,756,287	24,098,742
Operating lease liability, net of current portion		647,532
Total liabilities	22,756,287	24,746,274
Commitments and contingencies (Note 8)
Stockholders' equity:
Preferred stock, $0.001 par value, 5,000,000 shares authorized: none issued and outstanding at December 31, 2020 and 2019	0
Common stock, $0.001 par value, 200,000,000 and 150,000,000 shares authorized; 103,781,641 shares and 103,397,033 shares issued and outstanding at December 31, 2020 and 2019, respectively	103,782	103,397
Additional paid-in capital	223,168,149	216,205,678
Accumulated deficit	(53,705,624)	(128,688,624)
Accumulated other comprehensive income (loss)	31,332	9,505
Total stockholders' equity	169,597,639	87,629,956
Total liabilities and stockholders' equity	$ 192,353,926	$ 112,376,230

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2020	Dec. 31, 2019
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	200,000,000	150,000,000
Common stock, shares issued	103,781,641	103,397,033
Common stock, shares outstanding	103,781,641	103,397,033

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (LOSS) (unaudited) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenues:
Product revenue, net	$ 118,740,617	$ 102,306,337
Revenue, Product and Service [Extensible List]	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember
Revenues from collaborative arrangements	$ 332,186		$ 500,000
Total revenues	119,072,803	$ 102,306,337	$ 500,000
Operating costs and expenses:
Cost of sales	$ 17,039,157	$ 14,759,139
Cost, Product and Service [Extensible List]	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember
Research and development	$ 16,496,715	$ 18,842,752	$ 19,919,204
Selling, general and administrative	44,233,754	36,881,187	15,875,961
Total operating costs and expenses	77,769,626	70,483,078	35,795,165
Operating income (loss)	41,303,177	31,823,259	(35,295,165)
Other income, net	586,897	1,585,774	1,291,651
Net income (loss) before income taxes	41,890,074	33,409,033	(34,003,514)
Income tax provision (benefit)	(33,092,926)	1,533,696	0
Net income (loss)	$ 74,983,000	$ 31,875,337	$ (34,003,514)
Net income (loss) per share:
Basic	$ 0.72	$ 0.31	$ (0.33)
Diluted	$ 0.71	$ 0.30	$ (0.33)
Weighted average shares outstanding:
Basic	103,512,913	102,944,316	102,633,884
Diluted	106,242,273	106,020,936	102,633,884
Net income (loss)	$ 74,983,000	$ 31,875,337	$ (34,003,514)
Other comprehensive income (loss):
Unrealized gain (loss) on available-for-sale securities	21,827	29,753	(20,248)
Comprehensive income (loss)	$ 75,004,827	$ 31,905,090	$ (34,023,762)

CONSOLIDATED STATEMENTS OF CHAN

CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (unaudited) - 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)
Beginning Balance (shares) at Dec. 31, 2017		102,549,498
Issuance of common stock, net	10,549	$ 3	10,546
Issuance of common stock, net (shares)		3,094
Issuance of stock options for services	3,535,647		3,535,647
Exercise of stock options for common stock	297,563	$ 187	297,376
Exercise of stock options for common stock (shares)		186,665
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)
Ending Balance (shares) at Dec. 31, 2018		102,739,257
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
Exercise of stock options for common stock (shares)		657,776
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
Ending Balance (shares) at Dec. 31, 2019		103,397,033
Issuance of stock options for services	5,694,120		5,694,120
Exercise of stock options for common stock	$ 758,130	$ 282	757,848
Exercise of stock options for common stock (shares)	281,762	281,762
Amortization of restricted stock for services	$ 566,803		566,803
Issuance of common stock upon vesting of restricted stock units, net	(56,197)	$ 103	(56,300)
Issuance of common stock upon vesting of restricted stock units, net (Share)		102,846
Other comprehensive gain (loss)	21,827				21,827
Net income (loss)	74,983,000			74,983,000
Ending Balance at Dec. 31, 2020	$ 169,597,639	$ 103,782	$ 223,168,149	$ (53,705,624)	$ 31,332
Ending Balance (shares) at Dec. 31, 2020		103,781,641

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS (unaudited) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Operating Activities:
Net income (loss)	$ 74,983,000	$ 31,875,337	$ (34,003,514)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation	92,065	54,327	37,978
Amortization of right-of-use asset	793,252	243,399
Stock-based compensation	6,260,923	3,824,815	3,550,644
Deferred taxes	(32,971,264)
Change in accrued interest and accretion of discount on investments	(12,191)	(290,805)	(443,139)
(Increase) decrease in:
Accounts receivable, net	4,549,571	(10,536,997)
Inventory	(2,693,808)	(1,900,780)	(56,012)
Prepaid expenses and other current assets and deposits	(3,976,697)	(2,701,293)	(476,037)
Increase (decrease) in:
Accounts payable	138,573	1,780,080	391,792
Accrued expenses and other liabilities	(1,209,280)	12,540,197	4,850,743
Operating lease liability	(919,280)	(276,807)
Net cash provided by (used in) operating activities	45,034,864	34,611,473	(26,147,545)
Investing Activities:
Purchases of property and equipment	(11,398)	(19,369)	(92,018)
Purchases of investments	(10,000,000)	(34,725,401)	(36,790,854)
Proceeds from maturities and sales of investments	5,000,000	71,969,365	21,800,000
Net cash provided by (used in) investing activities	(5,011,398)	37,224,595	(15,082,872)
Financing Activities:
Payment of employee withholding tax related to stock-based compensation	(56,197)		(4,448)
Proceeds from exercise of stock options	758,130	1,116,242	297,563
Net cash provided by (used in) financing activities	701,933	1,116,242	293,115
Net increase (decrease) in cash and cash equivalents	40,725,399	72,952,310	(40,937,302)
Cash and cash equivalents – beginning of period	89,511,710	16,559,400	57,496,702
Cash and cash equivalents – end of period	130,237,109	89,511,710	16,559,400
Supplemental disclosures of cash flow information:
Cash paid for income taxes	2,785,497
Non-cash investing and financing activities:
Unrealized gain (loss) on available-for-sale securities	$ 21,827	$ 29,753	$ (20,248)

Organization and Description of

Organization and Description of Business	12 Months Ended
	Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Description of Business	1. Organization and Descript i Catalyst Pharmaceuticals, Inc. and subsidiary (collectively, the “Company”) is a commercial-stage biopharmaceutical company focused on developing and commercializing innovative therapies for people with rare debilitating, chronic neuromuscular and neurological diseases, including Lambert-Eaton Myasthenic Syndrome (LEMS) and Anti-MuSK antibody positive myasthenia gravis (MuSK-MG). The Company (f/k/a Catalyst Pharmaceutical Partners, Inc.) was incorporated in Delaware in July 2006. It is the successor by merger to Catalyst Pharmaceutical Partners, Inc., a Florida corporation, which commenced operations in January 2002. On November 28, 2018, the U.S. Food and Drug Administration, or FDA, granted approval of Firdapse ® ® On August 6, 2020, the Company announced that Canada’s national healthcare regulatory agency, Health Canada, has approved 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 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 drug 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. Risks and Uncertainties There are many uncertainties regarding the novel coronavirus (COVID-19) COVID-19 COVID-19

Basis of Presentation and Signi

Basis of Presentation and Significant Accounting Policies	12 Months Ended
	Dec. 31, 2020
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. c. CASH AND CASH EQUIVALENTS. d. INVESTMENTS. The short-term bond funds and U.S. Treasuries held at December 3 1 available-for-sale non-current The Company records available-for-sale available-for-sale available-for-sale The Company previously owned a short-term bond fund that was classified as trading securities. Trading securities are recorded at fair value based on the closing market price of the security. For trading securities, the Company recognized realized gains and losses and unrealized gains and losses to earnings. At December 31, 2020 and 2019, there were no investments classified as trading securities, as the Company sold its interest in the short-term bond fund classified as trading securities in 2019 . e. ACCOUNTS RECEIVABLE, NET. Accounts receivable are recorded net of customer allowance for distribution fees, trade discounts, prompt payment discounts, chargebacks and expected credit losses. Allowances for distribution fees, trade discounts, prompt payment discounts and chargebacks are based on contractual terms. The Company estimates the allowance for expected credit losses based on existing contractual payment terms, actual payment patterns of its customer and customer circumstances. At December 31, 2020 and 2019, the Company determined that an allowance for expected credit losses was not required. No accounts were written off during the periods presented. f. INVENTORY . work-in-process Cost is determined using a standard cost method, which approximates actual cost, and assumes a first-in, first out (FIFO) flow of goods. 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, 2020 and 2019, inventory consisted mainly of work-in-process and finished goods. 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. three four 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 December 31, 2020 Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Cash and cash equivalents: Money market funds $ 15,673,626 $ 15,673,626 $ — $ — U.S. Treasuries $ 104,994,400 $ — $ 104,994,400 $ — Short-term investments: Short-term bond funds $ 10,041,068 $ 10,041,068 $ — $ — Balances as of December 31, 2019 Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (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 $ — k. OPERATING LEASES. right-of-use non-lease l. REVENUE RECOGNITION. ® ® ® ® To determine revenue recognition for arrangements that are within the scope of Accounting Standards Codification (“ASC”) Topic 606 – Revenue from Contracts with Customers (“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 generate revenues from payments received under a collaborative agreement. Collaborative agreement payments may include nonrefundable fees at the inception of the agreements, contingent payments for specific achievements designated in the collaborative agreements, and/or net profit-sharing payments on sales of products resulting from a collaborative arrangement. For a complete discussion of accounting for collaborative arrangements, see Revenues from Collaborative Arrangements below. Product Revenue, Net: ® ® 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 or upon dispense to patient). 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 years ended December 31, 2020 and 2019. During the years ended December 31, 2020 and 2019, all of the Company’s sales of Firdapse ® Reserves for Variable Consideration: These estimates take into consideration a range of possible outcomes which are probability-weighted in accordance with the expected value method in Topic 606 for relevant factors such as current contractual and statutory requirements, specific known market events and trends, industry data, and forecasted customer buying and payment patterns. Overall, these reserves reflect the Company’s best estimates of the amount of consideration to which it is entitled based on the terms of the respective underlying contracts. 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 contemplates 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, 2020 and, therefore, the transaction price was not reduced further during the years ended December 31, 2020 and 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: ® Prompt Payment Discounts: Funded Co-pay co-pay co-pay ® Product Returns: Provider Chargebacks and Discounts: Government Rebates: Bridge and Patient Assistance Programs: ® pre-established ® ® ® ® Revenues from Collaborative Arrangements: ® ® net-profit Nonrefundable upfront license fees are recognized upon receipt or over time based on a determination of whether access to the Company’s intellectual property is throughout the license period, or whether the right is provided as the intellectual property exists as the point in time in which the license is granted. In the third quarter of 2020, an upfront fee was earned under the collaboration agreement for the commercialization of Firdapse ® The collaborative agreements provide for milestone payments upon achievement of development and regulatory events. The Company accounts for milestone payments as variable consideration in accordance with Topic 606. The Company recognizes sales-based sales-based In arrangements where the Company does not deem the collaborator to be a customer, payments to and from the collaborator are presented in the statement of operations based on the nature of the Company’s business operations, the nature of the arrangement, including the contractual terms, and the nature of the payments. Under the arrangements, the Company will receive profit-sharing reports 60 days after quarter end from one collaborator, and within nine days after quarter end from the other collaborator. Since the Company will receive these reports 60 days after quarter end, profit-sharing revenue from sales of collaboration products by the Company’s collaborator will be recognized in the quarter following the quarter in which the corresponding sales occurred. In instances where profit-sharing reports are received within nine days after quarter end, revenue from sales of collaboration products by the Company’s collaborator will be recognized in the quarter in which the sales occurred. For the year ended December 31, 2020, there was profit-sharing revenue of approximately $ from sales of the collaborative product in Canada. For the years ended December , and , there was profit-sharing revenue from sales of the collaborative product. Refer to Note 7 (Collaborative Arrangements), for further discussion on the Company’s collaborative arrangements. m. RESEARCH AND DEVELOPMENT. n. STOCK-BASED COMPENSATION. The Company recognizes expense in the consolidated statements of operations and comprehensive income (loss) for the fair value of all stock-based payments to employees, directors and consultants, including grants of stock options and other share-based awards. For stock options, the Company uses the Black-Scholes option valuation model, the single-option award approach, and the straight-line attribution method. one o. CONCENTRATION OF RISK. 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 expected credit loss 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 ® ® ® p. ROYALTIES. 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 On March 27, 2020, the Coronavirus Aid, Relief, and Economic Security (CARES) Act was signed into law making several changes to the Internal Revenue Code. The changes include, but are not limited to: increasing the limitation on the amount of deductible interest expense, allowing companies to carryback certain net operating losses, and increasing the amount of net operating loss carryforwards that corporations can use to offset taxable income. The tax law changes in the CARES Act did not have a material impact on the Company’s income tax provision. r. COMPREHENSIVE INCOME (LOSS). available-for-sale s. NET INCOME (LOSS) PER COMMON SHARE. Diluted net income (loss) per common share is computed by dividing net income (loss) by the weighted average number of common shares outstanding, increased by the assumed conversion of other potentially dilutive securities during the period. The following table reconciles basic and diluted weighted average common shares: For the Years Ended December 31, 2020 2019 2018 Basic weighted average common shares outstanding 103,512,913 102,944,316 102,633,884 Effect of dilutive securities 2,729,360 3,076,620 — Diluted weighted average common shares outstanding 106,242,273 106,020,936 102,633,884 Outstanding common stock equivalents totaling approximately 7.1 million and 4.6 million, were excluded from the calculation of diluted net income (loss) per common share for the years ended December 31, 2020 and 2019, respectively, 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, 2020, 2019 and 2018 had exercise prices ranging from $0.79 to $3.95, $0.79 to $4.20 and $0.79 to $4.64, respectively. t. SEGMENT INFORMATION. u. RECLASSIFICATIONS. v. RECENTLY ISSUED ACCOUNTING STANDARDS. In November 2018, the FASB issued ASU 2018-18, Collaborative Arrangements (Topic 808) 2014-09 2018-18 In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments — Credit Losses (Topic 326), Measurement of Credit Losses on Financial Instruments available-for-sale In August 2018, the FASB issued ASU 2018-15, Intangibles – Goodwill and Other – Internal-Use 350-40), internal-use internal-use 350-40 The Securities and Exchange Commission, or SEC, issued a final rule on November 19, 2020, adopting amendments to Regulation S-K In December 2019, the FASB issued ASU 2019-12, Income Taxes: Simplifying the Accounting for Income Taxes step-up

Investments

Investments	12 Months Ended
	Dec. 31, 2020
Investments, Debt and Equity Securities [Abstract]
Investments	3. Investments. Available-for-sale Estimated Fair Value Gross Unrealized Gains Gross Unrealized Losses Amortized Cost At December 31, 2020: U.S. Treasuries - Cash equivalents $ 104,994,400 $ 2,709 $ — $ 104,991,691 Bond Funds - ST 10,041,068 28,623 — 10,012,445 Total $ 115,035,468 $ 31,332 $ — $ 115,004,136 At December 31, 2019: U.S. Treasuries - Cash equivalents $ 59,932,200 $ 2,042 $ — $ 59,930,158 U.S. Treasuries - ST 5,007,050 7,463 — 4,999,587 Total $ 64,939,250 $ 9,505 $ — $ 64,929,745 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, 2020. The estimated fair values of available-for-sale 2020 Due in one year or less $ 115,035,468

Prepaid Expenses and Other Curr

Prepaid Expenses and Other Current Assets	12 Months Ended
	Dec. 31, 2020
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: 2020 2019 Prepaid manufacturing costs $ 3,327,610 $ 1,526,013 Prepaid tax 1,368,464 — Prepaid insurance 1,285,104 1,263,129 Prepaid subscriptions fees 729,065 501,251 Prepaid research fees 453,034 481,057 Prepaid commercialization expenses 199,095 62,959 Due from collaborative arrangements 436,784 — Other 528,615 516,665 Total prepaid expenses and other current assets $ 8,327,771 $ 4,351,074

Operating Leases

Operating Leases	12 Months Ended
	Dec. 31, 2020
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 Company entered into an agreement in May 2020 that amended its lease for its office facilities. Under the amended lease, the Company’s leased space will increase from approximately 7,800 square feet of space to approximately 10,700 square feet of space. The amended lease commenced in early 2021 when construction of the asset was completed and space became available for use. Consequently, the Company will record the effects of the amended lease during Q1 2021 which will be material to the Company’s consolidated financial statements. The lease disclosures for the year ended December 31, 2020 in these financial statements have been adjusted for the modification of the current lease. For the Year Ended December 31, 2020 Operating lease cost $ 261,736 Supplemental cash flow information related to leases was as follows: December 31, 2020 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows $ 339,605 Right-of-use Operating leases $ 55,801 Supplemental balance sheet information related to leases was as follows: December 31, 2020 Operating lease right-of-use $ — Other current liabilities $ 28,772 Operating lease liabilities, net of current portion — Total operating lease liabilities $ 28,772 Weighted average remaining lease term 0.1 years Weighted average discount rate 3.68 % Remaining payments of lease liabilities as o f 2021 $ 28,860 2022 — Total lease payments 28,860 Less imputed interest (88 ) Total $ 28,772 Rent expense was $278,753, $318,346 and $242,155 for the years ended December 31, 2020, 2019 and 2018.

Accrued Expenses and Other Liab

Accrued Expenses and Other Liabilities	12 Months Ended
	Dec. 31, 2020
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: 2020 2019 Accrued preclinical and clinical trial expenses $ 584,502 $ 1,183,513 Accrued professional fees 1,883,880 1,241,526 Accrued compensation and benefits 3,991,056 3,064,645 Accrued license fees 10,372,642 8,751,991 Accrued purchases 258,067 1,313,310 Accrued contributions 310,000 1,535,000 Operating lease liability 28,772 300,518 Accrued variable consideration 964,316 884,764 Accrued income tax — 1,533,696 Other 107,032 172,332 Current accrued expenses and other liabilities 18,500,267 19,981,295 Lease liability – non-current — 647,532 Non-current — 647,532 Total accrued expenses and other liabilities $ 18,500,267 $ 20,628,827

Collaborative Arrangements

Collaborative Arrangements	12 Months Ended
	Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Collaborative Arrangements	7. Collaborative Arrangements In December 2018, the Company entered into a collaboration and license agreement (Collaboration) with Endo, for the further development and commercialization of generic Sabril ® 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 mid-double-digit ® ten The collaborative agreement provides for a $2.0 million milestone payment on the commercial launch of the product by Par. As of December 31, 2020, 2019, and 2018, no milestone payments have been earned. Revenues from collaborative arrangement with Endo for years ended December 31, 2020, 2019, and 2018 were $0, $0 and $500,000 (for upfront license fees). Total expenses incurred, net, in connection with the collaborative agreement with Endo for years ended December 31, 2020, 2019, and 2018 were approximately respectively. These expenses have been included in research and development expenses in the accompanying consolidated statements of operations and comprehensive income (loss). In August 2020, the Company entered into a collaboration and license agreement with KYE Pharmaceuticals Inc (KYE), for the commercialization of Firdapse ® Under the agreement, KYE assumes all selling and marketing costs under the collaboration, while the Company is responsible for supply of Firdapse ® Under the terms of the agreement, the Company will receive an up-front payment, received payment upon transfer of Marketing Authorization and delivery of commercial product, received payment for supply of Firdapse®, will receive milestone payments, and a sharing of defined net profits upon commercialization from KYE consisting of a mid-double-digit percent of net sales of Firdapse®. 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 Revenues from arrangement with KYE for the year ended December 31, 2020 were approximately $332,000 . Total expenses incurred, net, in connection with the agreement with KYE for the year ended December 31, 2020 were approximately These expenses have been included in selling, general and administrative expenses in the accompanying consolidated statements of operations and comprehensive income (loss). The agreement provides for event-based payments subject to achievement of specified development, regulatory and sales-based milestones.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2020
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 payment on May 21, 2019, which is reported as income in other income, net in the consolidated statement of operations and comprehensive income (loss). The Company is also entitled to receive certain contingent compensation that will be reported when and if received. In May 2019, the FDA approved a New Drug Application (NDA) for Jacobus Pharmaceuticals for Ruzurgi ® ® ® ® ® ® The Company believes that the FDA’s approval of Ruzurgi ® alleged ® sought ® On July 30, 2020, the Magistrate Judge considering the Company’s lawsuit against the FDA filed a Report and Recommendation in which she recommended to the District Judge handling the case that she grant the FDA’s and Jacobus’ motions for summary judgment and deny the Company’s motion for summary judgment. On September 29, 2020, the District Judge adopted the Report and Recommendation of the Magistrate Judge, granted the FDA’s and Jacobus’s motions for summary judgment, and dismissed the Company’s case. The Company has appealed the decision to the Eleventh Circuit Court of Appeals. There can be no assurance as to the outcome of this lawsuit. On August 10, 2020, Health Canada issued a Notice of Compliance (NOC) to Medunik for Ruzurgi ® ® ® Monograph clearly references pivotal nonclinical carcinogenicity and reproductive toxicity data for amifampridine phosphate developed by the Company. As such, the Company believes that its data was relied upon to establish the nonclinical safety profile 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, 2020
Text Block [Abstract]
Agreements	9. Agreements. a. LICENSE AGREEMENT WITH BIOMARIN (FIRDAPSE ® ). ® ® ® for the duration of any regulatory exclusivity within a territory and 3.5% for territories in any calendar year in territories without regulatory exclusivity On May 29, 2019, the Company entered into an amendment to its license agreement for Firdapse ® ® In January 2020, the Company was advised that BioMarin has transferred certain rights under the license agreement to SERB S.A. b. AGREEMENTS FOR DRUG MANUFACTURING, DEVELOPMENT, PRECLINICAL AND CLINICAL STUDIES. The

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Income Taxes	10. Income Taxes. The Company is subject to income taxes in the U.S. federal jurisdiction and various states jurisdictions. For the year ended December 31, 2018, due to the Company’s historical operating losses and the inability to recognize any income tax benefit, there was no provision for income taxes presented in these financial statements for that respective period. Commencing in 2019, the Company has recorded income taxes on their pretax income using an effective tax rate. The income tax expense (benefit) for the years ended December 31, 2020, 2019, and 2018 consists of: 2020 2019 2018 Current $ (121,662 ) $ 1,533,696 $ — Deferred (32,971,264 ) — — $ (33,092,926 ) $ 1,533,696 $ — The reconciliation of i 2020 2019 2018 Statutory rate 21.0 % 21.0 % 21.0 % State tax 2.2 % 6.5 % 4.2 % Valuation allowanc e (99.4 )% (20.9 )% (25.9 )% Tax credit (2.4 )% (2.5 )% 1.4 % Othe r (0.4 )% 0.5 % (0.7 )% (79.0 )% 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, 2020 and 2019 are as follows: 2020 2019 Net operating loss $ 2,319,848 $ 10,645,128 Start-up 11,203,034 12,894,926 Tax credits 15,615,681 14,320,860 Deferred compensation 3,889,133 3,183,767 Inventory 212,045 229,050 Prepaid expenses (398,979 ) — Other 130,502 355,023 Gross deferred tax asset 32,971,264 41,628,754 Valuation allowance — (41,628,754 ) Net deferred tax assets $ 32,971,264 $ — The Company has evaluated the positive and negative evidence bearing upon the realizability of its deferred tax assets. As of December 31, 2020, the Company determined that there is sufficient positive evidence to conclude that it is more likely than not that the above deferred taxes of approximately $33.0 million are realizable. Accordingly, the Company has released the full valuation allowance for deferred tax assets including net operating loss December 31, 2020. The valuation allowance released over the course of the year ended December 31, 2020 was At December 31, 2020 and 2019, respectively, the Company had federal net operating loss carryforwards of approximately The federal net operating loss carryforwards are expected to be utilized within the next year. Additionally, at December 31, 2020 and 2019, respectively, the Company had state net operating loss carryforwards of approximately $42 million and $52 million available to reduce future Florida taxable income. The state During 2020, the Company completed an analysis to determine whether, as a result of prior ownership changes, the utilization of certain net operating loss and orphan drug tax credit carryforwards would be subject to annual limitations under Sections 382 and 383 of the Internal Revenue Code and similar state provisions. In this analysis, the Company determined that the total net operating loss and orphan drug tax credit carryforwards are fully utilizable. Thus, the deferred tax assets were adjusted accordingly. 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 orphan drug credit carryforwards will expire at various dates beginning in 2031. No interest or penalties were accrued through December 31, 2020. The Company’s policy is to recognize any related interest or penalties in income tax expense. The Company is not currently under income tax examinations by any tax authorities.

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2020
Equity [Abstract]
Stockholders' Equity	11. Stockholders’ Equity. Preferred Stock The Company has 5,000,000 shares of authorized preferred stock, $0.001 par value per share, at December 31, 2020 and 2019. No shares of preferred stock were outstanding at December 31, 2020 and 2019. Common Stock On August 20, 2020, the Company’s stockholders approved an increase in the Company’s authorized common stock par value $0.001 per share, from 150,000,000 shares to 200,000,000 shares. At December 31, 2020 and 2019, 103,781,641 and 103,397,033 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. 2020 Shelf Registration Statement On July 23, 2020, the Company filed a shelf registration statement with the SEC to sell up to $200 million of common stock, preferred stock, warrants to purchase common stock, debt securities and units consisting of one or more of such securities (the “2020 Shelf Registration Statement”). The 2020 Shelf Registration Statement (file no. 333-240052) 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 October 7, 2011. Each Right entitles the holder to purchase from the Company one one-hundredth The Rights trade automatically with the common stock and will not be exercisable until a person or group has become an “acquiring person” by acquiring 17.5% or more of the Company’s outstanding common stock, or a person or group commences, or publicly announces a tender offer that will result in such a person or group owning 17.5% or more of the Company’s outstanding common stock. Upon announcement that any person or group has become an acquiring person, each Right will entitle all rightholders (other than the acquiring person) to purchase, for the exercise price of $7.80, a number of shares of the Company’s common stock having a market value equal to twice the exercise price. Rightholders would also be entitled to purchase common stock of the acquiring person having a value of twice the exercise price if, after a person had become an acquiring person, the Company were to enter into certain mergers or other transactions. If any person becomes an acquiring person, the Board of Directors may, at its option and subject to certain limitations, exchange one share of common stock for each Right. The Rights have certain anti-takeover effects, in that they would cause substantial dilution to a person or group that attempts to acquire a significant interest in the Company on terms not approved by the Board of Directors. In the event that the Board of Directors determines a transaction to be in the best interests of the Company and its stockholders, the Board of Directors may redeem the Rights for $0.001 per share at any time prior to a person or group becoming an acquiring person. On September 19, 2016, the Board of Directors unanimously approved, and on the same date the Company entered into Amendment No. 1 to the Stockholders Rights Plan (the “Amendment”). Under the terms of the Amendment, the outside expiration date of the rights plan was On August 28, 2019, the Board of Directors unanimously adopted Amendment No. 2 to the Stockholders’ Rights Plan further extending the outside expiration date of the rights plan to September 20, 2022.

Stock Compensation

Stock Compensation	12 Months Ended
	Dec. 31, 2020
Share-based Payment Arrangement [Abstract]
Stock Compensation	12. Stock Compensation. For the years ended December 31, 2020, 2019 and 2018, the Company recorded stock-based compensation expense as follows: 2020 2019 2018 Research and development $ 1,585,202 $ 1,137,596 $ 1,079,230 Selling, general and administrative 4,675,721 2,687,219 2,471,414 Total stock-based compensation $ 6,260,923 $ 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, 2020, no shares remain available for future issuance under the 2014 Plan. Under the 2018 Plan, 10,000,000 shares were reserved for issuance and as of December 31, 2020, 1,856,008 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 3 years of continuous service and have contractual terms of 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, 2020, 2019, and 2018, options to purchase 281,762, 654,332 and 186,665 shares , respectively, During years and 2018, During the years ended December 31, 2020, 2019, and 2018 the Company recorded non-cash During the years ended December 31, 2020, 2019, and 2018, the Company granted seven-year Stock option activity under the Company’s Plans for the year ended December 31, 2020 is summarized as follows: Number of Options Weighted Average Exercise Price Weighted Average Remaining Contractual Term (in years) Aggregate Intrinsic Value Outstanding at beginning of year 11,478,334 $ 2.95 Granted 2,715,000 3.75 Exercised or released (281,762 ) 2.69 Forfeited or cancelled (160,668 ) 3.84 Expired (357,235 ) 3.38 Outstanding at end of year 13,393,669 $ 3.10 4.42 $ 8,237,645 Exercisable at end of year 7,926,136 $ 2.64 3.38 $ 7,381,601 Other information pertaining to stock option activity during the years ended December 31, 2020, 2019, and 2018 was as follows: 2020 2019 2018 Weighted–average fair value of granted stock options $ 2.33 $ 2.69 $ 1.93 Total fair value of vested stock options $ 5,311,616 $ 3,864,995 $ 2,193,294 Total intrinsic value of exercised stock options $ 325,102 $ 1,899,862 $ 274,864 As of December 31, 2020, there was approximately $10.02 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, 2020 December 31, 2019 December 31, 2018 Risk free interest rate 0.24% to 1.64 % 1.51% to 2.53 % 2.09% to 2.88 % Expected term 4.5 years 4.5 years 0 to 7 years Expected volatility 80.5% to 83.7 % 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 2020 Number of Stock Units Weighted Average Grant Date Fair Value Nonvested balance at beginning of year 352,500 $ 4.64 Granted 30,000 4.70 Vested (117,495 ) 4.64 Forfeited (29,334 ) 4.64 Nonvested balance at end of year 235,671 $ 4.65 During the year ended December 31, 2019, 352,500 r During the year ended December 31, 2020 and 2019, the Company recorded non-cash Common Stock No shares of common stock were granted during the year ended December 31, 2020 or 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, 2020
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

Basis of Presentation and Sig_2

Basis of Presentation and Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
PRINCIPLES OF CONSOLIDATION.	a. PRINCIPLES OF CONSOLIDATION.
USE OF ESTIMATES	b. USE OF ESTIMATES.
CASH AND CASH EQUIVALENTS	c. CASH AND CASH EQUIVALENTS.
INVESTMENTS	d. INVESTMENTS. The short-term bond funds and U.S. Treasuries held at December 3 1 available-for-sale non-current The Company records available-for-sale available-for-sale available-for-sale The Company previously owned a short-term bond fund that was classified as trading securities. Trading securities are recorded at fair value based on the closing market price of the security. For trading securities, the Company recognized realized gains and losses and unrealized gains and losses to earnings. At December 31, 2020 and 2019, there were no investments classified as trading securities, as the Company sold its interest in the short-term bond fund classified as trading securities in 2019 .
ACCOUNTS RECEIVABLE, NET	e. ACCOUNTS RECEIVABLE, NET. Accounts receivable are recorded net of customer allowance for distribution fees, trade discounts, prompt payment discounts, chargebacks and expected credit losses. Allowances for distribution fees, trade discounts, prompt payment discounts and chargebacks are based on contractual terms. The Company estimates the allowance for expected credit losses based on existing contractual payment terms, actual payment patterns of its customer and customer circumstances. At December 31, 2020 and 2019, the Company determined that an allowance for expected credit losses was not required. No accounts were written off during the periods presented.
INVENTORY	f. INVENTORY . work-in-process Cost is determined using a standard cost method, which approximates actual cost, and assumes a first-in, first out (FIFO) flow of goods. 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, 2020 and 2019, inventory consisted mainly of work-in-process and finished goods. 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. three four
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 December 31, 2020 Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Cash and cash equivalents: Money market funds $ 15,673,626 $ 15,673,626 $ — $ — U.S. Treasuries $ 104,994,400 $ — $ 104,994,400 $ — Short-term investments: Short-term bond funds $ 10,041,068 $ 10,041,068 $ — $ — Balances as of December 31, 2019 Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (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 $ —
OPERATING LEASES	k. OPERATING LEASES. right-of-use non-lease
REVENUE RECOGNITION	l. REVENUE RECOGNITION. ® ® ® ® To determine revenue recognition for arrangements that are within the scope of Accounting Standards Codification (“ASC”) Topic 606 – Revenue from Contracts with Customers (“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 generate revenues from payments received under a collaborative agreement. Collaborative agreement payments may include nonrefundable fees at the inception of the agreements, contingent payments for specific achievements designated in the collaborative agreements, and/or net profit-sharing payments on sales of products resulting from a collaborative arrangement. For a complete discussion of accounting for collaborative arrangements, see Revenues from Collaborative Arrangements below. Product Revenue, Net: ® ® 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 or upon dispense to patient). 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 years ended December 31, 2020 and 2019. During the years ended December 31, 2020 and 2019, all of the Company’s sales of Firdapse ® Reserves for Variable Consideration: These estimates take into consideration a range of possible outcomes which are probability-weighted in accordance with the expected value method in Topic 606 for relevant factors such as current contractual and statutory requirements, specific known market events and trends, industry data, and forecasted customer buying and payment patterns. Overall, these reserves reflect the Company’s best estimates of the amount of consideration to which it is entitled based on the terms of the respective underlying contracts. 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 contemplates 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, 2020 and, therefore, the transaction price was not reduced further during the years ended December 31, 2020 and 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: ® Prompt Payment Discounts: Funded Co-pay co-pay co-pay ® Product Returns: Provider Chargebacks and Discounts: Government Rebates: Bridge and Patient Assistance Programs: ® pre-established ® ® ® ® Revenues from Collaborative Arrangements: ® ® net-profit Nonrefundable upfront license fees are recognized upon receipt or over time based on a determination of whether access to the Company’s intellectual property is throughout the license period, or whether the right is provided as the intellectual property exists as the point in time in which the license is granted. In the third quarter of 2020, an upfront fee was earned under the collaboration agreement for the commercialization of Firdapse ® The collaborative agreements provide for milestone payments upon achievement of development and regulatory events. The Company accounts for milestone payments as variable consideration in accordance with Topic 606. The Company recognizes sales-based sales-based In arrangements where the Company does not deem the collaborator to be a customer, payments to and from the collaborator are presented in the statement of operations based on the nature of the Company’s business operations, the nature of the arrangement, including the contractual terms, and the nature of the payments. Under the arrangements, the Company will receive profit-sharing reports 60 days after quarter end from one collaborator, and within nine days after quarter end from the other collaborator. Since the Company will receive these reports 60 days after quarter end, profit-sharing revenue from sales of collaboration products by the Company’s collaborator will be recognized in the quarter following the quarter in which the corresponding sales occurred. In instances where profit-sharing reports are received within nine days after quarter end, revenue from sales of collaboration products by the Company’s collaborator will be recognized in the quarter in which the sales occurred. For the year ended December 31, 2020, there was profit-sharing revenue of approximately $ from sales of the collaborative product in Canada. For the years ended December , and , there was profit-sharing revenue from sales of the collaborative product. Refer to Note 7 (Collaborative Arrangements), for further discussion on the Company’s collaborative arrangements.
RESEARCH AND DEVELOPMENT	m. RESEARCH AND DEVELOPMENT.
STOCK-BASED COMPENSATION	n. STOCK-BASED COMPENSATION. The Company recognizes expense in the consolidated statements of operations and comprehensive income (loss) for the fair value of all stock-based payments to employees, directors and consultants, including grants of stock options and other share-based awards. For stock options, the Company uses the Black-Scholes option valuation model, the single-option award approach, and the straight-line attribution method. one
CONCENTRATION OF CREDIT RISK	o. CONCENTRATION OF RISK. 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 expected credit loss 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 ® ® ®
ROYALTIES	p. ROYALTIES.
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 On March 27, 2020, the Coronavirus Aid, Relief, and Economic Security (CARES) Act was signed into law making several changes to the Internal Revenue Code. The changes include, but are not limited to: increasing the limitation on the amount of deductible interest expense, allowing companies to carryback certain net operating losses, and increasing the amount of net operating loss carryforwards that corporations can use to offset taxable income. The tax law changes in the CARES Act did not have a material impact on the Company’s income tax provision.
COMPREHENSIVE INCOME (LOSS)	r. COMPREHENSIVE INCOME (LOSS). available-for-sale
NET INCOME (LOSS) PER COMMON SHARE	s. NET INCOME (LOSS) PER COMMON SHARE. Diluted net income (loss) per common share is computed by dividing net income (loss) by the weighted average number of common shares outstanding, increased by the assumed conversion of other potentially dilutive securities during the period. The following table reconciles basic and diluted weighted average common shares: For the Years Ended December 31, 2020 2019 2018 Basic weighted average common shares outstanding 103,512,913 102,944,316 102,633,884 Effect of dilutive securities 2,729,360 3,076,620 — Diluted weighted average common shares outstanding 106,242,273 106,020,936 102,633,884 Outstanding common stock equivalents totaling approximately 7.1 million and 4.6 million, were excluded from the calculation of diluted net income (loss) per common share for the years ended December 31, 2020 and 2019, respectively, 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, 2020, 2019 and 2018 had exercise prices ranging from $0.79 to $3.95, $0.79 to $4.20 and $0.79 to $4.64, respectively.
SEGMENT INFORMATION	t. SEGMENT INFORMATION.
RECLASSIFICATIONS	u. RECLASSIFICATIONS.
RECENTLY ISSUED ACCOUNTING STANDARDS	v. RECENTLY ISSUED ACCOUNTING STANDARDS. In November 2018, the FASB issued ASU 2018-18, Collaborative Arrangements (Topic 808) 2014-09 2018-18 In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments — Credit Losses (Topic 326), Measurement of Credit Losses on Financial Instruments available-for-sale In August 2018, the FASB issued ASU 2018-15, Intangibles – Goodwill and Other – Internal-Use 350-40), internal-use internal-use 350-40 The Securities and Exchange Commission, or SEC, issued a final rule on November 19, 2020, adopting amendments to Regulation S-K In December 2019, the FASB issued ASU 2019-12, Income Taxes: Simplifying the Accounting for Income Taxes step-up

Basis of Presentation and Sig_3

Basis of Presentation and Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Fair Value Measurement Specific to Assets or Liability	Fair Value Measurements at Reporting Date Using Balances as of December 31, 2020 Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Cash and cash equivalents: Money market funds $ 15,673,626 $ 15,673,626 $ — $ — U.S. Treasuries $ 104,994,400 $ — $ 104,994,400 $ — Short-term investments: Short-term bond funds $ 10,041,068 $ 10,041,068 $ — $ — Balances as of December 31, 2019 Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (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 $ —
Basic and Dilutive Weighted Average Common Shares	The following table reconciles basic and diluted weighted average common shares: For the Years Ended December 31, 2020 2019 2018 Basic weighted average common shares outstanding 103,512,913 102,944,316 102,633,884 Effect of dilutive securities 2,729,360 3,076,620 — Diluted weighted average common shares outstanding 106,242,273 106,020,936 102,633,884

Investments (Tables)

Investments (Tables)	12 Months Ended
	Dec. 31, 2020
Investments, Debt and Equity Securities [Abstract]
Summary of Available-for-Sale Investments by Security type	Available-for-sale Estimated Fair Value Gross Unrealized Gains Gross Unrealized Losses Amortized Cost At December 31, 2020: U.S. Treasuries - Cash equivalents $ 104,994,400 $ 2,709 $ — $ 104,991,691 Bond Funds - ST 10,041,068 28,623 — 10,012,445 Total $ 115,035,468 $ 31,332 $ — $ 115,004,136 At December 31, 2019: U.S. Treasuries - Cash equivalents $ 59,932,200 $ 2,042 $ — $ 59,930,158 U.S. Treasuries - ST 5,007,050 7,463 — 4,999,587 Total $ 64,939,250 $ 9,505 $ — $ 64,929,745
Estimated Fair Values of Available for Sale Securities	The estimated fair values of available-for-sale 2020 Due in one year or less $ 115,035,468

Prepaid Expenses and Other Cu_2

Prepaid Expenses and Other Current Assets (Tables)	12 Months Ended
	Dec. 31, 2020
Text Block [Abstract]
Prepaid expenses and other current assets	Prepaid expenses and other current assets consist of the following as of December 31: 2020 2019 Prepaid manufacturing costs $ 3,327,610 $ 1,526,013 Prepaid tax 1,368,464 — Prepaid insurance 1,285,104 1,263,129 Prepaid subscriptions fees 729,065 501,251 Prepaid research fees 453,034 481,057 Prepaid commercialization expenses 199,095 62,959 Due from collaborative arrangements 436,784 — Other 528,615 516,665 Total prepaid expenses and other current assets $ 8,327,771 $ 4,351,074

Operating Leases (Tables)

Operating Leases (Tables)	12 Months Ended
	Dec. 31, 2020
Disclosure of Operating Leases [Abstract]
Lease, Cost	The components of lease expense for the old leased space were as follows: For the Year Ended December 31, 2020 Operating lease cost $ 261,736
Schedule of Supplemental Cash Flow Information Related To Lease	Supplemental cash flow information related to leases was as follows: December 31, 2020 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows $ 339,605 Right-of-use Operating leases $ 55,801
Schedule of Supplemental Balance Sheet related To Lease	Supplemental balance sheet information related to leases was as follows: December 31, 2020 Operating lease right-of-use $ — Other current liabilities $ 28,772 Operating lease liabilities, net of current portion — Total operating lease liabilities $ 28,772 Weighted average remaining lease term 0.1 years Weighted average discount rate 3.68 %
Lessee, Operating Lease, Liability, Maturity	Remaining payments of lease liabilities as o f 2021 $ 28,860 2022 — Total lease payments 28,860 Less imputed interest (88 ) Total $ 28,772

Accrued Expenses and Other Li_2

Accrued Expenses and Other Liabilities (Tables)	12 Months Ended
	Dec. 31, 2020
Payables and Accruals [Abstract]
Schedule of Accrued Expenses and Other Liabilities	Accrued expenses and other liabilities consist of the following as of December 31: 2020 2019 Accrued preclinical and clinical trial expenses $ 584,502 $ 1,183,513 Accrued professional fees 1,883,880 1,241,526 Accrued compensation and benefits 3,991,056 3,064,645 Accrued license fees 10,372,642 8,751,991 Accrued purchases 258,067 1,313,310 Accrued contributions 310,000 1,535,000 Operating lease liability 28,772 300,518 Accrued variable consideration 964,316 884,764 Accrued income tax — 1,533,696 Other 107,032 172,332 Current accrued expenses and other liabilities 18,500,267 19,981,295 Lease liability – non-current — 647,532 Non-current — 647,532 Total accrued expenses and other liabilities $ 18,500,267 $ 20,628,827

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Schedule of income tax expense	The income tax expense (benefit) for the years ended December 31, 2020, 2019, and 2018 consists of: 2020 2019 2018 Current $ (121,662 ) $ 1,533,696 $ — Deferred (32,971,264 ) — — $ (33,092,926 ) $ 1,533,696 $ —
Reconciliation of income tax expense (Benefit) computed at statutory federal income tax rate	The reconciliation of i 2020 2019 2018 Statutory rate 21.0 % 21.0 % 21.0 % State tax 2.2 % 6.5 % 4.2 % Valuation allowanc e (99.4 )% (20.9 )% (25.9 )% Tax credit (2.4 )% (2.5 )% 1.4 % Othe r (0.4 )% 0.5 % (0.7 )% (79.0 )% 4.6 % 0.0 %
Components of deferred tax assets	Significant components of the Company’s deferred tax assets as of December 31, 2020 and 2019 are as follows: 2020 2019 Net operating loss $ 2,319,848 $ 10,645,128 Start-up 11,203,034 12,894,926 Tax credits 15,615,681 14,320,860 Deferred compensation 3,889,133 3,183,767 Inventory 212,045 229,050 Prepaid expenses (398,979 ) — Other 130,502 355,023 Gross deferred tax asset 32,971,264 41,628,754 Valuation allowance — (41,628,754 ) Net deferred tax assets $ 32,971,264 $ —

Stock Compensation (Tables)

Stock Compensation (Tables)	12 Months Ended
	Dec. 31, 2020
Share-based Payment Arrangement [Abstract]
Stock-Based Compensation Expense	For the years ended December 31, 2020, 2019 and 2018, the Company recorded stock-based compensation expense as follows: 2020 2019 2018 Research and development $ 1,585,202 $ 1,137,596 $ 1,079,230 Selling, general and administrative 4,675,721 2,687,219 2,471,414 Total stock-based compensation $ 6,260,923 $ 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, 2020 is summarized as follows: Number of Options Weighted Average Exercise Price Weighted Average Remaining Contractual Term (in years) Aggregate Intrinsic Value Outstanding at beginning of year 11,478,334 $ 2.95 Granted 2,715,000 3.75 Exercised or released (281,762 ) 2.69 Forfeited or cancelled (160,668 ) 3.84 Expired (357,235 ) 3.38 Outstanding at end of year 13,393,669 $ 3.10 4.42 $ 8,237,645 Exercisable at end of year 7,926,136 $ 2.64 3.38 $ 7,381,601
Schedule of Other Information Pertaining to Stock Option Activity	Other information pertaining to stock option activity during the years ended December 31, 2020, 2019, and 2018 was as follows: 2020 2019 2018 Weighted–average fair value of granted stock options $ 2.33 $ 2.69 $ 1.93 Total fair value of vested stock options $ 5,311,616 $ 3,864,995 $ 2,193,294 Total intrinsic value of exercised stock options $ 325,102 $ 1,899,862 $ 274,864
Summary of Stock Options Awards Based on Certain Assumptions	Assumptions used during the years were as follows: December 31, 2020 December 31, 2019 December 31, 2018 Risk free interest rate 0.24% to 1.64 % 1.51% to 2.53 % 2.09% to 2.88 % Expected term 4.5 years 4.5 years 0 to 7 years Expected volatility 80.5% to 83.7 % 75.5 % 82 % Expected dividend yield — % — % — % Expected forfeiture rate — % — % — %
Summary of Restricted Stock Unit Activity	Restricted stock unit activity during 2020 was as follows:​​​​​​​ 2020 Number of Stock Units Weighted Average Grant Date Fair Value Nonvested balance at beginning of year 352,500 $ 4.64 Granted 30,000 4.70 Vested (117,495 ) 4.64 Forfeited (29,334 ) 4.64 Nonvested balance at end of year 235,671 $ 4.65

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, 2020USD ($)Segment$ / sharesshares	Dec. 31, 2019USD ($)$ / 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	3 years
Stock option exercise price range, Minimum | $ / shares	$ 0.79	$ 0.79	$ 0.79
Stock option exercise price range, Maximum | $ / shares	$ 3.95	$ 4.20	$ 4.64
Trading Securities, Realized Gain (Loss)		$ 80,045	$ 0
Trading securities, realized or unrealized gain (loss)	$ 0
Potential equivalent common stock excluded | shares	7.1	4.6	10.5
Trading securities	$ 0	$ 0
Number of Reportable Segments | Segment	1
Canada [Member]
Summary Of Basis Of Presentation And Significant Accounting Policies [Line Items]
Revenue from collaborative product	$ 33,000	0	$ 0
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, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	$ 10,041,068	$ 5,007,050
Short-Term Bond Fund [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments Fair Value Disclosure		5,007,050
Short-term investments	10,041,068
U.S. Treasuries [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	104,994,400	59,932,200
Money Market Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	15,673,626	23,963,617
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]
Short-term investments	10,041,068
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]
Cash and cash equivalents	15,673,626	23,963,617
Significant Other Observable Inputs (Level 2) [Member] | Short-Term Bond Fund [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments Fair Value Disclosure		5,007,050
Significant Other Observable Inputs (Level 2) [Member] | U.S. Treasuries [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	$ 104,994,400	$ 59,932,200

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, 2020	Dec. 31, 2019	Dec. 31, 2018
Weighted Average Number of Shares Outstanding Reconciliation [Abstract]
Basic weighted average common shares outstanding	103,512,913	102,944,316	102,633,884
Effect of dilutive securities	2,729,360	3,076,620
Dilutive weighted average common shares outstanding	106,242,273	106,020,936	102,633,884

Investments - Additional Inform

Investments - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Realized gains losses from available for sale securities	$ 0	$ 0	$ 0

Investment - Summary of Availab

Investment - Summary of Available-for-Sale Investments by Security type (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Net Investment Income [Line Items]
Amortized cost	$ 115,004,136	$ 64,929,745
Gross Unrealized Gains	31,332	9,505
Gross Unrealized Losses
Estimated Fair Value	115,035,468	64,939,250
U.S. Treasuries - ST [Member]
Net Investment Income [Line Items]
Amortized cost		4,999,587
Gross Unrealized Gains		7,463
Estimated Fair Value		5,007,050
U.S Treasury Bond Securities Cash Equivalents [Member]
Net Investment Income [Line Items]
Amortized cost	104,991,691	59,930,158
Gross Unrealized Gains	2,709	2,042
Estimated Fair Value	104,994,400	$ 59,932,200
Bond Funds – ST [Member]
Net Investment Income [Line Items]
Amortized cost	10,012,445
Gross Unrealized Gains	28,623
Estimated Fair Value	$ 10,041,068

Investment - Estimated Fair Val

Investment - Estimated Fair Values of Available for Sale Securities (Detail) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Investments, Debt and Equity Securities [Abstract]
Estimated Fair Value	$ 115,035,468	$ 64,939,250

Prepaid Expenses and Other Cu_3

Prepaid Expenses and Other Current Assets - Prepaid Expenses and Other Current Assets (Detail) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Prepaid manufacturing costs	$ 3,327,610	$ 1,526,013
Prepaid tax	1,368,464
Prepaid insurance	1,285,104	1,263,129
Prepaid subscriptions fees	729,065	501,251
Prepaid research fees	453,034	481,057
Prepaid commercialization expenses	199,095	62,959
Due from collaborative arrangements	436,784	0
Other	528,615	516,665
Total prepaid expenses and other current assets	$ 8,327,771	$ 4,351,074

Operating Leases - Operating Le

Operating Leases - Operating Leases (Detail)	12 Months Ended
	Dec. 31, 2020USD ($)
Disclosure of Operating Leases [Abstract]
Operating lease cost	$ 261,736

Operating Leases - Schedule of

Operating Leases - Schedule of Supplemental Cash Flow Information Related To Lease (Detail)	12 Months Ended
	Dec. 31, 2020USD ($)
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows	$ 339,605
Right-of-use assets obtained in exchange for lease obligations:
Operating leases	$ 55,801

Operating Leases -Schedule of S

Operating Leases -Schedule of Supplemental Balance Sheet related To Lease (Detail) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Disclosure of Operating Leases [Line Items]
Operating lease right-of-use assets		$ 793,252
Other current liabilities	$ 28,772	300,518
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	us-gaap:OtherAccruedLiabilitiesCurrent
Operating lease liabilities, net of current portion		$ 647,532
Total operating lease liabilities	$ 28,772
Weighted average remaining lease term	1 month 6 days
Weighted average discount rate	3.68%

Operating Leases -Lessee, Opera

Operating Leases -Lessee, Operating Lease, Liability, Maturity (Detail)	Dec. 31, 2020USD ($)
Disclosure of Operating Leases [Line Items]
2021	$ 28,860
2022
Total lease payments	28,860
Less imputed interest	(88)
Total	$ 28,772

Operating Leases - Additional

Operating Leases - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2020USD ($)ft²	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)
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 | $	$ 278,753	$ 318,346	$ 242,155
Before agreement of company leased spaces | ft²	7,800
After agreement of company leased spaces | ft²	10,700

Accrued Expenses and Other Li_3

Accrued Expenses and Other Liabilities - Schedule of Accrued Expenses and Other Liabilities (Detail) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Payables and Accruals [Abstract]
Accrued preclinical and clinical trial expenses	$ 584,502	$ 1,183,513
Accrued professional fees	1,883,880	1,241,526
Accrued compensation and benefits	3,991,056	3,064,645
Accrued license fees	10,372,642	8,751,991
Accrued purchases	258,067	1,313,310
Accrued contributions	310,000	1,535,000
Operating lease liability	28,772	300,518
Accrued variable consideration	964,316	884,764
Accrued income tax		1,533,696
Other	107,032	172,332
Current accrued expenses and other liabilities	18,500,267	19,981,295
Lease liability - non-current		647,532
Non-current accrued expenses and other liabilities		647,532
Total accrued expenses and other liabilities	$ 18,500,267	$ 20,628,827

Collaborative Arrangement - Add

Collaborative Arrangement - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Collaborative Arrangements [Line Items]
Period of collaboration agreement	10 years
Expenses In Connection With Collaborative Arrangement	$ 16,496,715	$ 18,842,752	$ 19,919,204
Revenues	119,072,803	102,306,337	500,000
Collaborative Arrangement [Member]
Collaborative Arrangements [Line Items]
Milestone payments	2,000,000
Milestone payments income	0	0	0
Expenses In Connection With Collaborative Arrangement	4,254	65,061	0
Revenues	$ 0	$ 0	$ 500,000
Collaborative Arrangement [Member] | KYE Pharmaceuticals [Member] | CA [Member]
Collaborative Arrangements [Line Items]
Period of collaboration agreement	10 years
Revenues	$ 332,000
Collaborative Arrangement [Member] | KYE Pharmaceuticals [Member] | CA [Member] | Selling, General and Administrative Expenses [Member]
Collaborative Arrangements [Line Items]
Expenses In Connection With Collaborative Arrangement	$ 257,500

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) $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)
License Agreement [Line Items]
Percentage of royalty on net sales	3.50%
License Agreement with BioMarin [Member]
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
License Agreement with BioMarin [Member] | Minimum [Member]
License Agreement [Line Items]
Percentage of royalty on net sales	7.00%
License Agreement with BioMarin [Member] | 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) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Current	$ (121,662)	$ 1,533,696	$ 0
Deferred	(32,971,264)	0	0
Total income tax expense	$ (33,092,926)	$ 1,533,696	$ 0

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Line Items]
Deferred tax assets recognised in income statement	$ (32,971,264)	$ 0	$ 0
Increase (decrease) in valuation allowance on deferred tax assets	41,600,000
Net operating loss carryforwards	$ 3,000,000	45,000,000
Net operating loss carryforwards expiration date	beginning in 2033
Interest or penalties accrued	$ 0
Tax credit carryforwards expiration date	2031 years
State and Local Jurisdiction [Member]
Income Tax Disclosure [Line Items]
Net operating loss carryforwards	$ 42,000,000	$ 52,000,000

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, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Statutory rate	21.00%	21.00%	21.00%
State tax	2.20%	6.50%	4.20%
Valuation allowance	(99.40%)	(20.90%)	(25.90%)
Tax credit	(2.40%)	(2.50%)	1.40%
Other	(0.40%)	0.50%	(0.70%)
Reconciliation of income tax expense (benefit)	(79.00%)	4.60%	0.00%

Income Taxes - Components of De

Income Taxes - Components of Deferred Tax Assets (Detail) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Components of Deferred Tax Assets [Abstract]
Net operating loss	$ 2,319,848	$ 10,645,128
Start-up costs	11,203,034	12,894,926
Tax credits	15,615,681	14,320,860
Deferred compensation	3,889,133	3,183,767
Inventory	212,045	229,050
Prepaid expenses	(398,979)	0
Other	130,502	355,023
Gross deferred tax asset	32,971,264	41,628,754
Valuation allowance	0	(41,628,754)
Net deferred tax assets	$ 32,971,264	$ 0

Stockholders' Equity (Preferred

Stockholders' Equity (Preferred Stock and Common Stock) - Additional Information (Detail)	Dec. 31, 2020Vote$ / sharesshares	Dec. 31, 2019$ / sharesshares
Stockholders Equity [Line Items]
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	200,000,000	150,000,000
Common stock, par value | $ / shares	$ 0.001	$ 0.001
Common stock, shares issued	103,781,641	103,397,033
Common stock, shares outstanding	103,781,641	103,397,033
Number of votes entitled for each share of common stock | Vote	1

Stockholders' Equity (2020 Shel

Stockholders' Equity (2020 Shelf Registration Statement) - Additional Information (Detail) $ in Millions	Jul. 23, 2020USD ($)
2020 Shelf Registration Statement [Member]
Stockholders' Equity [Line Items]
Maximum dollar amount of common stock to be issued under shelf registration statement	$ 200

Stockholders' Equity (Stockhold

Stockholders' Equity (Stockholder Rights Plan) - Additional Information (Detail) - $ / shares	Sep. 19, 2016	Sep. 20, 2011	Dec. 31, 2020
Series A Preferred Stock [Member]
Stockholders Equity [Line Items]
Preferred Stock Purchase Price		$ 7.80
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, Extended	Sep. 20, 2019
Certificate Of Designation [Member] | Series A Preferred Stock [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

Stock Compensation - Stock-Base

Stock Compensation - Stock-Based Compensation Expense (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation	$ 6,260,923	$ 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	1,585,202	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	$ 4,675,721	$ 2,687,219	$ 2,471,414

Stock Compensation - Additional

Stock Compensation - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of stock options exercised	281,762
Proceeds from exercise of stock options	$ 758,130	$ 1,116,242	$ 297,563
Common stock unit granted	2,715,000
Stock option contractual term	3 years 4 months 17 days
Expected dividend rate	0.00%
Non Vested Outstanding		352,500
Non Vested granted		352,500
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]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option contractual term	7 years
Stock Option [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share based compensation, vesting period	1 year
Stock Option [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share based compensation, vesting period	3 years
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Non-cash stock-based compensation expense	$ 566,803	$ 44,729
Non Vested Outstanding	235,671	352,500
Non Vested granted	30,000
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	10,000,000
Common stock shares available for future issuance under the Plan	1,856,008
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
Options to Purchase Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of stock options exercised	281,762	654,332	186,665
Proceeds from exercise of stock options	$ 758,130	$ 1,116,242	$ 297,563
Stock option granted, contractual term	7 years	7 years	7 years
Common stock unit granted	2,715,000	2,183,500	5,882,500
Unrecognized compensation expense related to non-vested stock compensation awards granted under the Plan	$ 10,020,000
Expected remaining weighted average vesting period	2 years 4 months 6 days
Non-cash stock-based compensation expense	$ 5,694,120	$ 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
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, 2020USD ($)$ / sharesshares
Share-based Payment Arrangement [Abstract]
Number of options, Outstanding at beginning of year | shares	11,478,334
Number of options, Granted | shares	2,715,000
Number of options, Exercised or released | shares	(281,762)
Number of options, Forfeited or cancelled | shares	(160,668)
Number of options, Expired | shares	(357,235)
Number of options, Outstanding at end of year | shares	13,393,669
Number of options, Exercisable at end of year | shares	7,926,136
Weighted average exercise price, Outstanding at beginning of year | $ / shares	$ 2.95
Weighted average exercise price, Granted | $ / shares	3.75
Weighted average exercise price, Exercised or released | $ / shares	2.69
Weighted average exercise price, Forfeited or cancelled | $ / shares	3.84
Weighted average exercise price, Expired | $ / shares	3.38
Weighted average exercise price, Outstanding at end of year | $ / shares	3.10
Weighted average exercise price, Exercisable at end of year | $ / shares	$ 2.64
Weighted Average Remaining Contractual Term (Years), Outstanding at end of year	4 years 5 months 1 day
Weighted Average Remaining Contractual Term (Years), Exercisable at end of year	3 years 4 months 17 days
Aggregate Intrinsic value, Outstanding at end of year | $	$ 8,237,645
Aggregate Intrinsic value, Exercisable at end of year | $	$ 7,381,601

Stock Compensation - Schedule o

Stock Compensation - Schedule of Other Information Pertaining to Stock Option Activity (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based Payment Arrangement [Abstract]
Weighted-average fair value of granted stock options	$ 2.33	$ 2.69	$ 1.93
Total fair value of vested stock options	$ 5,311,616	$ 3,864,995	$ 2,193,294
Total intrinsic value of exercised stock options	$ 325,102	$ 1,899,862	$ 274,864

Stock Compensation - Summary _2

Stock Compensation - Summary of Stock Options Awards Based on Certain Assumptions (Detail)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk free interest rate, Minimum	0.24%	1.51%	2.09%
Risk free interest rate, Maximum	1.64%	2.53%	2.88%
Expected volatility		75.50%	82.00%
Expected dividend yield	0.00%
Expected forfeiture rate	0.00%
Expected term	4 years 6 months	4 years 6 months
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility	80.50%
Expected term			0 years
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility	83.70%
Expected term			7 years

Stock Compensation - Summary _3

Stock Compensation - Summary of Restricted Stock Unit Activity (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Schedule Of Restricted Stock Activity [Line Items]
Nonvested balance at beginning of year	352,500
Granted		352,500
Nonvested balance at end of year		352,500
Restricted Stock Units (RSUs) [Member]
Schedule Of Restricted Stock Activity [Line Items]
Nonvested balance at beginning of year	352,500
Granted	30,000
Vested	117,495
Forfeited	29,334
Nonvested balance at end of year	235,671	352,500
Nonvested Weighted Average Grant Date Fair Value balance at beginning of year	$ 4.64
Weighted Average Grant Date Fair Value, Granted	4.70
Weighted Average Grant Date Fair Value, Vested	4.64
Weighted Average Grant Date Fair Value, Forfeited	4.64
Nonvested Weighted Average Grant Date Fair Value balance at end of year	$ 4.65	$ 4.64

Benefit Plan - Additional Infor

Benefit Plan - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2020	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	$ 465,000	$ 268,000	$ 123,000