Catalyst Pharmaceuticals (CPRX) 10-Q 9 Nov 21 2021 Q3 Quarterly report Financial data

Cover Page

Cover Page - shares	9 Months Ended
	Sep. 30, 2021	Nov. 05, 2021
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2021
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q3
Entity Registrant Name	CATALYST PHARMACEUTICALS, INC.
Entity Central Index Key	0001369568
Current Fiscal Year End Date	--12-31
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		103,117,579
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 Quarterly Report	true
Document Transition Report	false
Entity File Number	001-33057

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Current Assets:
Cash and cash equivalents	$ 154,836	$ 130,237
Short-term investments	19,956	10,041
Accounts receivable, net	6,625	5,987
Inventory	6,950	4,651
Prepaid expenses and other current assets	4,428	8,328
Total current assets	192,795	159,244
Operating lease right-of-use asset	3,093
Property and equipment, net	951	130
Deferred tax assets	26,400	32,971
Deposits	9	9
Total assets	223,248	192,354
Current Liabilities:
Accounts payable	2,752	4,256
Accrued expenses and other liabilities	17,862	18,500
Total current liabilities	20,614	22,756
Operating lease liability, net of current portion	3,973
Total liabilities	24,587	22,756
Commitments and contingencies (Note 10)
Stockholders' equity:
Preferred stock, $0.001 par value, 5,000,000 shares authorized: none issued and outstanding at September 30, 2021 and December 31, 2020	0
Common stock, $0.001 par value, 200,000,000 shares authorized; 103,153,459 shares and 103,781,641 shares issued and outstanding at September 30, 2021 and December 31, 2020, respectively	103	104
Additional paid-in capital	231,165	223,168
Accumulated deficit	(32,544)	(53,705)
Accumulated other comprehensive income (loss)	(63)	31
Total stockholders' equity	198,661	169,598
Total liabilities and stockholders' equity	$ 223,248	$ 192,354

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2021	Dec. 31, 2020
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	200,000,000
Common stock, shares issued	103,153,459	103,781,641
Common stock, shares outstanding	103,153,459	103,781,641

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Revenues:
Total revenues	$ 35,954	$ 29,317	$ 102,524	$ 88,058
Operating costs and expenses:
Cost of sales	$ 5,310	$ 3,879	$ 14,536	$ 12,170
Cost, Product and Service [Extensible List]	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember
Research and development	$ 4,487	$ 3,749	$ 11,944	$ 12,322
Selling, general and administrative	12,153	9,985	36,401	30,881
Total operating costs and expenses	21,950	17,613	62,881	55,373
Operating income	14,004	11,704	39,643	32,685
Other income, net	68	33	211	481
Net income before income taxes	14,072	11,737	39,854	33,166
Income tax provision (benefit)	3,743	(31,603)	9,681	(30,380)
Net income	$ 10,329	$ 43,340	$ 30,173	$ 63,546
Net income per share:
Basic	$ 0.10	$ 0.42	$ 0.29	$ 0.61
Diluted	$ 0.10	$ 0.41	$ 0.28	$ 0.60
Weighted average shares outstanding:
Basic	103,196,550	103,535,431	103,470,762	103,452,025
Diluted	107,843,196	106,316,241	107,476,175	106,386,617
Net income	$ 10,329	$ 43,340	$ 30,173	$ 63,546
Other comprehensive income:
Unrealized gain (loss) on available-for-sale securities	(26)	(5)	(94)	(16)
Comprehensive income	10,303	43,335	30,079	63,530
Product Revenue, Net [Member]
Revenues:
Total revenues	35,890	29,167	99,731	87,908
License and other [Member]
Revenues:
Total revenues	$ 64	$ 150	$ 2,793	$ 150

CONSOLIDATED STATEMENTS OF CHAN

CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (unaudited) - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Gain (Loss) [Member]
Beginning Balance at Dec. 31, 2019	$ 87,630	$ 103	$ 216,206	$ (128,689)	$ 10
Beginning Balance (shares) at Dec. 31, 2019		103,397,000
Issuance of stock options for services	1,384		1,384
Exercise of stock options for common stock	26		26
Exercise of stock options for common stock (shares)		12,000
Amortization of restricted stock for services	136		136
Other comprehensive gain (loss)	74				74
Net income	10,426			10,426
Ending Balance at Mar. 31, 2020	99,676	$ 103	217,752	(118,263)	84
Ending Balance (shares) at Mar. 31, 2020		103,409,000
Beginning Balance at Dec. 31, 2019	87,630	$ 103	216,206	(128,689)	10
Beginning Balance (shares) at Dec. 31, 2019		103,397,000
Net income	63,546
Ending Balance at Sep. 30, 2020	156,628	$ 103	221,674	(65,143)	(6)
Ending Balance (shares) at Sep. 30, 2020		103,648,000
Beginning Balance at Mar. 31, 2020	99,676	$ 103	217,752	(118,263)	84
Beginning Balance (shares) at Mar. 31, 2020		103,409,000
Issuance of stock options for services	1,627		1,627
Exercise of stock options for common stock	36		36
Exercise of stock options for common stock (shares)		13,000
Amortization of restricted stock for services	167		167
Other comprehensive gain (loss)	(85)				(85)
Net income	9,780			9,780
Ending Balance at Jun. 30, 2020	111,201	$ 103	219,582	(108,483)	(1)
Ending Balance (shares) at Jun. 30, 2020		103,422,000
Issuance of stock options for services	1,346		1,346
Exercise of stock options for common stock	631		631
Exercise of stock options for common stock (shares)		215,000
Amortization of restricted stock for services	132		132
Issuance of common stock upon vesting of restricted stock units, net	(17)		(17)
Issuance of common stock upon vesting of restricted stock units, net (shares)		11,000
Other comprehensive gain (loss)	(5)				(5)
Net income	43,340			43,340
Ending Balance at Sep. 30, 2020	156,628	$ 103	221,674	(65,143)	(6)
Ending Balance (shares) at Sep. 30, 2020		103,648,000
Beginning Balance at Dec. 31, 2020	169,598	$ 104	223,168	(53,705)	31
Beginning Balance (shares) at Dec. 31, 2020		103,782,000
Issuance of stock options for services	1,442		1,442
Exercise of stock options for common stock	188		188
Exercise of stock options for common stock (shares)		90,000
Amortization of restricted stock for services	129		129
Repurchase of common stock	(293)			(293)
Repurchase of common stock (shares)		(67,000)
Other comprehensive gain (loss)	(76)				(76)
Net income	7,663			7,663
Ending Balance at Mar. 31, 2021	178,651	$ 104	224,927	(46,335)	(45)
Ending Balance (shares) at Mar. 31, 2021		103,805,000
Beginning Balance at Dec. 31, 2020	$ 169,598	$ 104	223,168	(53,705)	31
Beginning Balance (shares) at Dec. 31, 2020		103,782,000
Repurchase of common stock (shares)	(1,749,746)
Net income	$ 30,173
Ending Balance at Sep. 30, 2021	198,661	$ 103	231,165	(32,544)	(63)
Ending Balance (shares) at Sep. 30, 2021		103,153,000
Beginning Balance at Mar. 31, 2021	178,651	$ 104	224,927	(46,335)	(45)
Beginning Balance (shares) at Mar. 31, 2021		103,805,000
Issuance of stock options for services	1,388		1,388
Exercise of stock options for common stock	271		271
Exercise of stock options for common stock (shares)		83,000
Amortization of restricted stock for services	130		130
Repurchase of common stock	(3,668)	$ (1)		(3,667)
Repurchase of common stock (shares)		(733,000)
Issuance of common stock upon vesting of restricted stock units, net	(17)		(17)
Issuance of common stock upon vesting of restricted stock units, net (shares)		7,000
Other comprehensive gain (loss)	8				8
Net income	12,181			12,181
Ending Balance at Jun. 30, 2021	188,944	$ 103	226,699	(37,821)	(37)
Ending Balance (shares) at Jun. 30, 2021		103,162,000
Issuance of stock options for services	1,380		1,380
Exercise of stock options for common stock	2,955	$ 1	2,954
Exercise of stock options for common stock (shares)		941,000
Amortization of restricted stock for services	132		132
Repurchase of common stock	$ (5,053)	$ (1)		(5,052)
Repurchase of common stock (shares)	(949,746)	(950,000)
Other comprehensive gain (loss)	$ (26)				(26)
Net income	10,329			10,329
Ending Balance at Sep. 30, 2021	$ 198,661	$ 103	$ 231,165	$ (32,544)	$ (63)
Ending Balance (shares) at Sep. 30, 2021		103,153,000

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS (unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Operating Activities:
Net income	$ 30,173	$ 63,546
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation	159	73
Stock-based compensation	4,601	4,792
Deferred taxes	6,571	(31,347)
Change in accrued interest and accretion of discount on investments	(9)	(12)
Reduction in the carrying amount of right-of-use asset	216	781
(Increase) decrease in:
Accounts receivable, net	(638)	4,665
Inventory	(2,299)	(2,791)
Prepaid expenses and other current assets and deposits	3,900	(1,263)
Increase (decrease) in:
Accounts payable	(1,504)	(2,112)
Accrued expenses and other liabilities	(916)	(3,570)
Operating lease liability	942	(833)
Net cash provided by (used in) operating activities	41,196	31,929
Investing Activities:
Purchases of property and equipment	(980)	(11)
Purchases of investments	(10,000)	(10,000)
Proceeds from maturities and sales of investments		5,000
Net cash provided by (used in) investing activities	(10,980)	(5,011)
Financing Activities:
Payment of employee withholding tax related to stock-based compensation	(17)	(17)
Proceeds from exercise of stock options	3,414	693
Repurchase of common stock	(9,014)
Net cash provided by (used in) financing activities	(5,617)	676
Net increase (decrease) in cash and cash equivalents	24,599	27,594
Cash and cash equivalents—beginning of period	130,237	89,512
Cash and cash equivalents—end of period	154,836	117,106
Supplemental disclosures of cash flow information:
Cash paid for income taxes	1,438	2,195
Non-cash investing and financing activities:
Unrealized gain (loss) on available-for-sale securities	(94)	$ (16)
Operating lease liabilities arising from obtaining right-of-use assets	$ 3,309

Organization and Description of

Organization and Description of Business	9 Months Ended
	Sep. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Description of Business	1. Organization and Description of Business. Catalyst Pharmaceuticals, Inc. and subsidiary (collectively, the “Company”) is a commercial-stage patient-centric biopharmaceutical company focused on in-licensing, 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 substanti a Capital Resources While there can be no assurance, based on currently available information, the Company estimates that it has sufficient resources to support its planned operations for at least the next 12 months from the issuance date of this Form 10-Q. The Company may raise 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 and if 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 numerous aspects of the coronavirus (COVID-19)

Basis of Presentation and Signi

Basis of Presentation and Significant Accounting Policies	9 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
Basis of Presentation and Significant Accounting Policies	2. Basis of Presentation and Significant Accounting Policies. a. INTERIM FINANCIAL STATEMENTS. 10-Q In the opinion of management, the accompanying unaudited interim consolidated financial statements of the Company contain all adjustments (consisting of only normal recurring adjustments) necessary to present fairly the financial position of the Company as of the dates and for the periods presented. Accordingly, these consolidated statements should be read in conjunction with the financial statements and notes thereto for the year ended December 31, 2020 included in the 2020 Annual Report on Form 10-K b. PRINCIPLES OF CONSOLIDATION c. USE OF ESTIMATES. d. CASH AND CASH EQUIVALENTS. e. INVESTMENTS The short-term bond funds and U.S. Treasuries held at September 30, 2021 are classified as available-for-sale securities. The short-term bond funds are classified as current assets, which reflects management’s intention to use the proceeds from the sale of these investments to fund the Company’s operations, as necessary. The Company classifies U.S. Treasuries with stated maturities of greater than three months and less than one year in short-term investments. U.S. Treasuries with stated maturities greater than one year are classified as non-current investments in the Company’s consolidated balance sheets. non-current The Company records available-for-sale available-for-sale available-for-sale available-for-sale f. ACCOUNTS RECEIVABLE, NET. g. INVENTORY. work-in-process first-in, ® ® work-in work-in-process 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. h. PREPAID EXPENSES AND OTHER CURRENT ASSETS. Prepaid expenses and other current assets consist primarily of prepaid manufacturing, prepaid tax, prepaid insurance, prepaid subscription fees, prepaid research fees, prepaid commercialization expenses, amounts due from collaborative and license arrangements and prepaid conference and travel expenses. Prepaid research fees consist of advances for the Company’s product development activities, including contracts for pre-clinical studies, clinical trials and studies, regulatory affairs and consulting. Prepaid manufacturing consists of advances for the Company’s drug manufacturing activities. Such advances are recorded as expense as the related goods are received or the related services are performed. i. FAIR VALUE OF FINANCIAL INSTRUMENTS. p 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 (in thousands) Balances Quoted Prices in Significant Significant Cash and cash equivalents: Money market funds $ 38,925 $ 38,925 $ — $ — U.S. Treasuries $ 104,995 $ 104,995 $ — $ — Short-term investments: Short-term bond funds $ 19,956 $ 19,956 $ — $ — Balances Quoted Prices in Significant Significant Cash and cash equivalents: Money market funds $ 15,674 $ 15,674 $ — $ — U.S. Treasuries $ 104,994 $ — $ 104,994 $ — Short-term investments: Short-term bond funds $ 10,041 $ 10,041 $ — $ — k. OPERATING LEASES. right-of-use non-lease l. SHARE REPURCHASES. The Company accounts for share repurchases by charging the excess of the repurchase price over the repurchased common stock’s par value entirely to accumulated deficit. All repurchased shares are retired and become authorized but unissued shares. The Company accrues for the shares purchased under the share repurchase plan based on the trade date. The Company may terminate or modify its share repurchase program at any time. m. REVENUE RECOGNITION. Product Revenues: The Company recognizes revenue when its customer obtains title of the promised goods, in an amount that reflects the consideration to which the Company expects to be entitled in exchange for these goods. The Company had contracts with customers until the FDA approved Firdapse ® in . Subsequent to receiving FDA approval, the Company entered into an arrangement with distributor (the “Customer”), which is the exclusive distributor of Firdapse ® in the United States. The Customer subsequently resells Firdapse ® to a small group of exclusive specialty pharmacies (“SPs”) whose dispensing activities for patients with specific payors may result in government-mandated or privately negotiated rebate obligations for the Company with respect to the purchase of Firdapse ® . 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 collaborative and license agreements. Collaborative and license agreement payments may include nonrefundable fees at the inception of the agreements, contingent payments for specific achievements designated in the agreements, and/or net profit-sharing payments on sales of products resulting from the collaborative and license arrangements. For a complete discussion of accounting for collaborative and licensing arrangements, see Revenues from Collaboration and Licensing 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 o During the three and nine months ended September 30, 2021 and 2020, principally all of the Company’s sales of Firdapse ® Reserves for Variable Consideration: Revenue from product sales is recorded at the net sales price (transaction price), which includes estimates of variable consideration for which reserves are established. Components of variable consideration include trade discounts and allowances, prompt payment discounts, product returns, provider chargebacks and discounts, government rebates, and other incentives, such as voluntary patient assistance, and other allowances that are offered within contracts between the Company and its Customer, payors, and other indirect customers relating to the Company’s sale of its products. These reserves, as d e 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 September 30, 2021 and, therefore, the transaction price was not reduced further during the three and nine months ended September 30, 2021 and 2020. 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: Consistent with industry practice, the Company offers the SPs and its distributor limited product return rights for damaged and expiring product, provided it is within a specified period around the product expiration date as set forth in the applicable individual distribution agreement. The Company estimates the amount of its product sales that may be returned by its Customer and records this estimate as a reduction of revenue in the period the related product revenue is recognized. The Company currently estimates product return liabilities using available industry data and its own sales information, including its visibility into the inventory remaining in the distribution channel. These payments are considered payable to the third-party vendor and the related reserve is recorded in the same period the related revenue is recognized, resulting in a reduction of product revenue and the establishment of a current liability which is included in accrued expenses and other current liabilities in the consolidated balance sheets. The Company has an insignificant amount of returns to date and believes that returns of its products will continue to be minimal. Provider Chargebacks and Discounts: Government Rebates: Bridge and Patient Assistance Programs: ® pre-established ® ® ® ® Revenues from Collaboration and Licensing Arrangements: The Company analyzes license and collaboration arrangements pursuant to FASB ASC Topic 808, Collaborative Arrangement Guidance and Consideration, (“Topic 808”) to assess whether such arrangements, or transactions between arrangement participants, involve joint operating activities performed by parties that are both active participants in the activities and exposed to significant risks and rewards dependent on the commercial success of such activities or are more akin to a vendor-customer relationship. In making this evaluation, the Company considers whether the activities of the collaboration are considered to be distinct and deemed to be within the scope of the collaborative arrangement guidance or if they are more reflective of a vendor-customer relationship and, therefore, within the scope of Topic 606. This assessment is performed throughout the life of the arrangement based on changes in the responsibilities of all parties in the arrangement. For elements of collaboration arrangements that are not accounted for pursuant to guidance in Topic 606, an appropriate recognition method is determined and applied consistently, generally by analogy to the revenue from contracts with customers guidance. Pursuant to Topic 606, for arrangements or transactions between arrangement participants determined to be within the scope of the contracts with customers guidance, the Company performs the following steps to determine the appropriate amount of revenue to be recognized as the Company fulfills its obligations: (i) identification of the promised goods or services in the contract; (ii) determination of whether the promised goods or services are performance obligations including whether they are distinct in the context of the contract; (iii) measurement of the transaction price, including the constraint on variable consideration; (iv) allocation of the transaction price to the performance obligations based on estimated selling prices; and (v) recognition of revenue when (or as) the Company satisfies each performance obligation. The Company evaluates the performance obligations promised in the contract that are based on goods and services that will be transferred to the customer and determines whether those obligations are both (i) capable of being distinct and (ii) distinct in the context of the contract. Goods or services that meet these criteria are considered distinct performance obligations. The Company estimates the transaction price based on the amount expected to be received for transferring the promised goods or services in the contract. The consideration may include fixed consideration or variable consideration. The 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. At the inception of each arrangement that includes variable consideration, the Company evaluates the amount of potential transaction price and the likelihood that the transaction price will be received. The Company utilizes either the most likely amount method or expected value method to estimate the a m Revenue is recognized when, or as, the Company satisfies a performance obligation by transferring a promised good or service to a customer. An asset is transferred when, or as, the customer obtains control of that asset. After contract inception, the transaction price is reassessed at every period end and updated for changes such as resolution of uncertain events. Any change in the overall transaction price is allocated to the performance obligations based on the same methodology used at contract inception. The Company recognizes sales-based royalties or net profit-sharing when the later of (a) the subsequent sale occurs, or (b) the performance obligation to which the sales-based royalty or net profit-sharing has been allocated has been satisfied. 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. Refer to Note 9 (Collaboration and Licensing Arrangements), for further discussion on the Company’s collaborative and licensing arrangements. n. RESEARCH AND DEVELOPMENT. o. STOCK-BASED COMPENSATION. one p. CONCENTRATION OF RISK. The Company sells its product in the United States through an exclusive distributor (its Customer) to SPs. Therefore, its distributor and SPs account for principally 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 ® ® ® q. ROYALTIES. r. 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 s. COMPREHENSIVE INCOME. available-for-sale t. NET INCOME PER COMMON SHARE. Diluted net income per common share is computed by dividing net income 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 Three Months Ended For the Nine Months Ended 2021 2020 2021 2020 Basic weighted average common shares outstanding 103,196,550 103,535,431 103,470,762 103,452,025 Effect of dilutive securities 4,646,646 2,780,810 4,005,413 2,934,592 Diluted weighted average common shares outstanding 107,843,196 106,316,241 107,476,175 106,386,617 Outstanding common stock equivalents totaling approximately 2.6 million and 5.3 million, were excluded from the calculation of diluted net income per common share for the three and nine months ended September 30, 2021 as their effect would be anti-dilutive. For the three and nine months ended September 30, 2020, approximately 5.4 million and 4.8 million shares of common stock equivalents were excluded from the calculation of diluted net income per common share as their effect would be anti-dilutive. u. RECLASSIFICATIONS. v. RECENTLY ISSUED ACCOUNTING STANDARDS. 2019-12, Income Taxes: Simplifying the Accounting for Income Taxes step-up

Investments

Investments	9 Months Ended
	Sep. 30, 2021
Investments, Debt and Equity Securities [Abstract]
Investments	3. Investments. Available-for-sale Estimated Gross Gross Amortized At September 30, 2021: U.S. Treasuries – Cash equivalents $ 104,995 $ — $ — $ 104,995 Short-term bond funds 19,956 — (63 ) 20,019 Total $ 124,951 $ — $ (63 ) $ 125,014 At December 31, 2020: U.S. Treasuries – Cash equivalents $ 104,994 $ 2 $ — $ 104,992 Short-term bond funds 10,041 29 — 10,012 Total $ 115,035 $ 31 $ — $ 115,004 There were no realized gains or losses from available-for-sale The estimated fair values of available-for-sale September 30, 2021 Due in one year or less $ 124,951

Inventory, net

Inventory, net	9 Months Ended
	Sep. 30, 2021
Inventory Disclosure [Abstract]
Inventory, net	4. Inventory, net. Inventory, net consists of the following (in thousands): September 30, 2021 December 31, 2020 Raw materials $ 1,112 $ — Work-in-process 4,847 3,555 Finished goods 991 1,096 Total inventory, net $ 6,950 $ 4,651

Prepaid Expenses and Other Curr

Prepaid Expenses and Other Current Assets	9 Months Ended
	Sep. 30, 2021
Text Block [Abstract]
Prepaid Expenses and Other Current Assets	5. Prepaid Expenses and Other Current Assets. Prepaid expenses and other current assets consist of the following (in thousands): September 30, 2021 December 31, 2020 Prepaid manufacturing costs $ 2,233 $ 3,328 Prepaid tax 13 1,368 Prepaid insurance 231 1,285 Prepaid subscription fees 689 729 Prepaid research fees 523 453 Prepaid commercialization expenses 90 199 Due from collaborative and licensing arrangements 197 437 Prepaid conference and travel expenses 224 83 Other 228 446 Total prepaid expenses and other current assets $ 4,428 $ 8,328

Operating Leases

Operating Leases	9 Months Ended
	Sep. 30, 2021
Disclosure of Operating Leases [Abstract]
Operating Leases	6. Operating Lease. The Company has an operating lease agreement for its corporate office. The lease includes an option to extend the lease for up to 5 years and options to terminate the lease within 6 and 7.6 years. 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 increased from approximately 7,800 square feet of space to approximately 10,700 square feet of space. The amended lease commenced in March 2021 when construction of the asset was completed and space became available for use. Consequently, the Company recorded the effects of the amended lease during Q1 2021. 17 The components of lease expense were as follows (in thousands): For the three For the nine Operating lease cost $ 108 $ 272 Supplemental cash flow information related to leases was as follows: September 30, 2021 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows $ 29 Right-of-use Operating leases $ 58 Supplemental balance sheet information related to leases was as follows: Operating lease right-of-use $ 3,093 Other current liabilities $ 278 Operating lease liabilities, net of current portion 3,973 Total operating lease liabilities $ 4,251 Remaining lease term 9.6 years Discount rate 4.51 % Remaining payments of lease liabilities as of September 30, 2021 were as follows (in thousands): 2021 (remaining three months) $ 80 2022 492 2023 506 2024 522 2025 537 Thereafter 3,150 Total lease payments 5,287 Less: imputed interest (1,036 ) Total $ 4,251 Rent expense was approximately $0.1 million and $0.3 million for the three and nine months ended September 30, 2021, respectively, and $0.1 million and $0.3 million for the three and nine months ended September 30, 2020, respectively.

Property and Equipment, net

Property and Equipment, net	9 Months Ended
	Sep. 30, 2021
Property, Plant and Equipment [Abstract]
Property and Equipment, net	7. Property and Equipment, net. Property and equipment, net consists of the following (in thousands): September 30, 2021 December 31, 2020 Computer equipment $ 51 $ 51 Furniture and equipment 203 242 Leasehold improvements 939 177 Less: Accumulated depreciation (242 ) (340 ) Total property and equipment, net $ 951 $ 130

Accrued Expenses and Other Liab

Accrued Expenses and Other Liabilities	9 Months Ended
	Sep. 30, 2021
Payables and Accruals [Abstract]
Accrued Expenses and Other Liabilities	8. Accrued Expenses and Other Liabilities. Accrued expenses and other liabilities consist of the following (in thousands): September 30, 2021 December 31, 2020 Accrued preclinical and clinical trial expenses $ 487 $ 585 Accrued professional fees 1,978 1,884 Accrued compensation and benefits 2,647 3,991 Accrued license fees 9,105 10,373 Accrued purchases 1,483 258 Accrued contributions — 310 Operating lease liability 278 29 Accrued variable consideration 1,439 964 Accrued income tax 335 — Other 110 106 Current accrued expenses and other liabilities 17,862 18,500 Lease liability—non-current 3,973 — Non-current 3,973 — Total accrued expenses and other liabilities $ 21,835 $ 18,500

Collaboration and Licensing Arr

Collaboration and Licensing Arrangements	9 Months Ended
	Sep. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Collaborative and Licensing Arrangements	9. Collaboration and Licensing Arrangements. Endo 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 terms of the Collaboration, the Company has received an up-front mid-double ® The Company evaluated the license agreement with Endo to determine whether it is a collaborative arrangement for purposes of Topic 808. As the Company shares in the significant risks and rewards, the Company has concluded that this is a collaborative arrangement. As developing a final finished dosage form of a generic product in exchange for consideration is not an output of the Company’s ongoing activities, Endo does not represent a contract with a customer. However, Topic 808 does not provide guidance on the recognition of consideration exchanged or accounting for the obligations that may arise between the parties. The Company concluded that ASC Topic 730, Research and Development The collaborative agreement included a nonrefundable upfront license fee that was recognized upon receipt following execution of the collaborative arrangement for vigabatrin tablets. The collaborative agreement provides for a $2.0 million milestone payment on the commercial launch of the product by Par. As of September 30, 2021 and 2020, no milestone payments have been earned. There were no revenues from this collaborative arrangement for the three or nine months ended September 30, 2021 or 2020. Total expenses incurred, net, in connection with the collaborative agreement for the three and nine months ended September 30, 2021 were approximately $0 and KYE Pharmaceuticals 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, Catalyst granted KYE an exclusive license to commercialize and market Firdapse ® ® Under the terms of the agreement, the Company will receive an up-front e ® mid-double-digit ® Although this agreement is in form identified as a collaborative agreement, the Company has concluded for accounting purposes that it represents a contract with a customer. This is because the Company grants to KYE a license and provides supply of Fi r ® The collaborative agreement included a nonrefundable upfront license fee that was recognized upon transfer of the license based on a determination that the right is provided as the intellectual property exists at the point in time in which the license is granted. Under the arrangement, the Company will receive profit-sharing reports within nine days after quarter end from the collaborator. Revenue from sales of collaboration products by the Company’s collaborator will be recognized in the quarter in which the sales occurred. Revenues from the arrangement with KYE for the three or nine months ended September 30, 2021 were material. Revenue is included in product revenue, net and license and other revenue in the accompanying consolidated statements of operations and comprehensive income. Expenses incurred, net have been included in selling, general and administrative expenses in the accompanying consolidated statements of operations and comprehensive income. DyDo Pharma, Inc. On June 28, 2021, the Company entered into a license agreement with DyDo Pharma, Inc. (DyDo), for the development and commercialization of Firdapse ® Under the agreement, DyDo has joint rights to develop Firdapse ® Under the terms of the agreement, the Company has earned an up-front ® The Company has concluded that this license agreement will be accounted for pursuant to Topic 606. The agreement included a nonrefundable upfront license fee that was recognized upon the effective date of the agreement as the intellectual property exists at the point in time in which the right to the license is granted. The Company determined the granting of the right to the license is distinct from the supply of Firdapse ® Additionally, the agreement includes sales-based milestones in which the license is deemed to be the predominant item to which these milestones relate. Revenue will be recognized when the later of (a) the subsequent sale occurs, or (b) the performance obligation to which the sales-based royalty has been allocated has been satisfied. Variable consideration related to regulatory milestones is fully constrained and only recognized when the uncertainty is subsequently resolved. For clinical and commercial supply of the product, the Company will recognize revenue when the Customer obtains control of the Company’s product, which will occur at a point in time which is generally at time of shipment. Revenue from the arrangement with DyDo for the three and nine months ended September 30, 2021 was approximately $0 and million, respectively, relating to the nonrefundable upfront license fee and is included in license and other revenue in the accompanying consolidated statements of operations and comprehensive income. As of September 30, 2021, milestone payments have been earned and there has been no clinical or commercial supply of ®

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2021
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	10. Commitments and Contingencies. In May 2019, the FDA approved a New Drug Application (NDA) for Jacobus Pharmaceuticals for Ruzurgi ® (3,4-DAP), ® ® ® ® off-label ® off-label The Company believes that the FDA’s approval of Ruzurgi ® ® ® 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 appealed the District Court’s decision to the Eleventh Circuit Court of Appeals. The case was fully briefed, and oral argument was held in March 2021. On September 30, 2021, a three-judge panel of judges on the Eleventh Circuit Court of Appeals issued a unanimous decision overturning the District Court’s decision. The court adopted the Company’s argument that the FDA’s approval of Ruzurgi ® ® ® On August 10, 2020, Health Canada issued a Notice of Compliance (NOC) to Medunik for Ruzurgi ® ® ® ® On June 3, 2021, the Company announced a positive decision in this proceeding that quashed the NOC previously issued for Ruzurgi ® ® ® re-issued ® 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	9 Months Ended
	Sep. 30, 2021
Text Block [Abstract]
Agreements	11. Agreements. a. LICENSE AGREEMENT FOR FIRDAPSE ® ® ® ® On May 29, 2019, the Company and BioMarin entered into an amendment to the Company’s 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.

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2021
Income Tax Disclosure [Abstract]
Income Taxes	12. Income Taxes. The Company’s effective income tax rate was 24.3% and 2.8% for the nine months ended September 30, 2021 and 2020, respectively. The difference in the effective rates between periods is driven by the release of the Company’s valuation allowance against deferred taxes in the third quarter of 2020. Differences in the effective tax and the statutory federal income tax rate of 21% are driven by state income taxes and anticipated annual permanent differences and offset by the orphan drug credit claimed. The Company had no uncertain tax positions as of September 30, 2021 and December 31, 2020.

Stockholders' Equity

Stockholders' Equity	9 Months Ended
	Sep. 30, 2021
Equity [Abstract]
Stockholders' Equity	13. Stockholders’ Equity. Preferred Stock The Company has 5,000,000 shares of authorized preferred stock, $0.001 par value per share, at September 30, 2021 and December 31, 2020. No shares of preferred stock were outstanding at September 30, 2021 and December 31, 2020. Common Stock The Company has 200,000,000 shares of authorized common stock, par value $0.001 per share. At September 30, 2021 and December 31, 2020, 103,153,459 and 103,781,641 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. Share Repurchases In March 2021, the Company’s Board of Directors approved a share repurchase program that authorizes the repurchase of up to $40 million of the Company’s common stock, pursuant to a repurchase plan under Rule 10b-18 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)

Stock Compensation

Stock Compensation	9 Months Ended
	Sep. 30, 2021
Share-based Payment Arrangement [Abstract]
Stock Compensation	14. Stock Compensation. For the three and nine months ended September 30, 2021 and 2020, the Company recorded stock-based compensation expense as follows (in thousands): Three months ended Nine months ended 2021 2020 2021 2020 Research and development $ 428 $ 399 $ 1,193 $ 1,239 Selling, general and administrative 1,084 1,079 3,408 3,553 Total stock-based compensation $ 1,512 $ 1,478 $ 4,601 $ 4,792 Stock Options As of September 30, 2021, there were outstanding stock options to purchase 13,162,504 shares of common stock, of which stock options to purchase 7,956,962 shares of common stock were exercisable as of September 30, 2021. During the three and nine months ended September 30, 2021, the Company granted seven During the three and nine months ended September 30, 2020, the Company granted seven During the three and nine months ended September 30, 2021, options to purchase 941,164 shares and 1,114,494 shares, respectively, of the Company’s common stock were exercised, with proceeds of $3.0 million and $3.4 million respectively, to the Company. During the three and nine months ended September 30, 2020, options to purchase 215,097 shares and 240,096 shares, respectively, of the Company’s common stock were exercised, with proceeds of $0.6 million and $0.7 million respectively, to the Company. As of September 30, 2021, there was approximately $8 million of unrecognized compensation expense related to non-vested Restricted Stock Units There were no grants of restricted stock units to employees or directors during the three or nine months ended September 30, 2021. The Company granted zero and 30,000 restricted stock units during the three and nine months ended September 30, 2020, respectively. During the three and nine months ended September 30, 2021, the Company recorded non-cash non-cash a As of September 30, 2021, there was approximately $0.6 million of unrecognized compensation expense related to non-vested

Basis of Presentation and Sig_2

Basis of Presentation and Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
INTERIM FINANCIAL STATEMENTS	a. INTERIM FINANCIAL STATEMENTS. 10-Q In the opinion of management, the accompanying unaudited interim consolidated financial statements of the Company contain all adjustments (consisting of only normal recurring adjustments) necessary to present fairly the financial position of the Company as of the dates and for the periods presented. Accordingly, these consolidated statements should be read in conjunction with the financial statements and notes thereto for the year ended December 31, 2020 included in the 2020 Annual Report on Form 10-K
PRINCIPLES OF CONSOLIDATION.	b. PRINCIPLES OF CONSOLIDATION
USE OF ESTIMATES	c. USE OF ESTIMATES.
CASH AND CASH EQUIVALENTS	d. CASH AND CASH EQUIVALENTS.
INVESTMENTS	e. INVESTMENTS The short-term bond funds and U.S. Treasuries held at September 30, 2021 are classified as available-for-sale securities. The short-term bond funds are classified as current assets, which reflects management’s intention to use the proceeds from the sale of these investments to fund the Company’s operations, as necessary. The Company classifies U.S. Treasuries with stated maturities of greater than three months and less than one year in short-term investments. U.S. Treasuries with stated maturities greater than one year are classified as non-current investments in the Company’s consolidated balance sheets. non-current The Company records available-for-sale available-for-sale available-for-sale available-for-sale
ACCOUNTS RECEIVABLE, NET	f. ACCOUNTS RECEIVABLE, NET.
INVENTORY	g. INVENTORY. work-in-process first-in, ® ® work-in work-in-process 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	h. PREPAID EXPENSES AND OTHER CURRENT ASSETS. Prepaid expenses and other current assets consist primarily of prepaid manufacturing, prepaid tax, prepaid insurance, prepaid subscription fees, prepaid research fees, prepaid commercialization expenses, amounts due from collaborative and license arrangements and prepaid conference and travel expenses. Prepaid research fees consist of advances for the Company’s product development activities, including contracts for pre-clinical studies, clinical trials and studies, regulatory affairs and consulting. Prepaid manufacturing consists of advances for the Company’s drug manufacturing activities. Such advances are recorded as expense as the related goods are received or the related services are performed.
FAIR VALUE OF FINANCIAL INSTRUMENTS	i. FAIR VALUE OF FINANCIAL INSTRUMENTS. p
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 (in thousands) Balances Quoted Prices in Significant Significant Cash and cash equivalents: Money market funds $ 38,925 $ 38,925 $ — $ — U.S. Treasuries $ 104,995 $ 104,995 $ — $ — Short-term investments: Short-term bond funds $ 19,956 $ 19,956 $ — $ — Balances Quoted Prices in Significant Significant Cash and cash equivalents: Money market funds $ 15,674 $ 15,674 $ — $ — U.S. Treasuries $ 104,994 $ — $ 104,994 $ — Short-term investments: Short-term bond funds $ 10,041 $ 10,041 $ — $ —
OPERATING LEASES	k. OPERATING LEASES. right-of-use non-lease
SHARE REPURCHASES	l. SHARE REPURCHASES. The Company accounts for share repurchases by charging the excess of the repurchase price over the repurchased common stock’s par value entirely to accumulated deficit. All repurchased shares are retired and become authorized but unissued shares. The Company accrues for the shares purchased under the share repurchase plan based on the trade date. The Company may terminate or modify its share repurchase program at any time.
REVENUE RECOGNITION	m. REVENUE RECOGNITION. Product Revenues: The Company recognizes revenue when its customer obtains title of the promised goods, in an amount that reflects the consideration to which the Company expects to be entitled in exchange for these goods. The Company had contracts with customers until the FDA approved Firdapse ® in . Subsequent to receiving FDA approval, the Company entered into an arrangement with distributor (the “Customer”), which is the exclusive distributor of Firdapse ® in the United States. The Customer subsequently resells Firdapse ® to a small group of exclusive specialty pharmacies (“SPs”) whose dispensing activities for patients with specific payors may result in government-mandated or privately negotiated rebate obligations for the Company with respect to the purchase of Firdapse ® . 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 collaborative and license agreements. Collaborative and license agreement payments may include nonrefundable fees at the inception of the agreements, contingent payments for specific achievements designated in the agreements, and/or net profit-sharing payments on sales of products resulting from the collaborative and license arrangements. For a complete discussion of accounting for collaborative and licensing arrangements, see Revenues from Collaboration and Licensing 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 o During the three and nine months ended September 30, 2021 and 2020, principally all of the Company’s sales of Firdapse ® Reserves for Variable Consideration: Revenue from product sales is recorded at the net sales price (transaction price), which includes estimates of variable consideration for which reserves are established. Components of variable consideration include trade discounts and allowances, prompt payment discounts, product returns, provider chargebacks and discounts, government rebates, and other incentives, such as voluntary patient assistance, and other allowances that are offered within contracts between the Company and its Customer, payors, and other indirect customers relating to the Company’s sale of its products. These reserves, as d e 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 September 30, 2021 and, therefore, the transaction price was not reduced further during the three and nine months ended September 30, 2021 and 2020. 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: Consistent with industry practice, the Company offers the SPs and its distributor limited product return rights for damaged and expiring product, provided it is within a specified period around the product expiration date as set forth in the applicable individual distribution agreement. The Company estimates the amount of its product sales that may be returned by its Customer and records this estimate as a reduction of revenue in the period the related product revenue is recognized. The Company currently estimates product return liabilities using available industry data and its own sales information, including its visibility into the inventory remaining in the distribution channel. These payments are considered payable to the third-party vendor and the related reserve is recorded in the same period the related revenue is recognized, resulting in a reduction of product revenue and the establishment of a current liability which is included in accrued expenses and other current liabilities in the consolidated balance sheets. The Company has an insignificant amount of returns to date and believes that returns of its products will continue to be minimal. Provider Chargebacks and Discounts: Government Rebates: Bridge and Patient Assistance Programs: ® pre-established ® ® ® ® Revenues from Collaboration and Licensing Arrangements: The Company analyzes license and collaboration arrangements pursuant to FASB ASC Topic 808, Collaborative Arrangement Guidance and Consideration, (“Topic 808”) to assess whether such arrangements, or transactions between arrangement participants, involve joint operating activities performed by parties that are both active participants in the activities and exposed to significant risks and rewards dependent on the commercial success of such activities or are more akin to a vendor-customer relationship. In making this evaluation, the Company considers whether the activities of the collaboration are considered to be distinct and deemed to be within the scope of the collaborative arrangement guidance or if they are more reflective of a vendor-customer relationship and, therefore, within the scope of Topic 606. This assessment is performed throughout the life of the arrangement based on changes in the responsibilities of all parties in the arrangement. For elements of collaboration arrangements that are not accounted for pursuant to guidance in Topic 606, an appropriate recognition method is determined and applied consistently, generally by analogy to the revenue from contracts with customers guidance. Pursuant to Topic 606, for arrangements or transactions between arrangement participants determined to be within the scope of the contracts with customers guidance, the Company performs the following steps to determine the appropriate amount of revenue to be recognized as the Company fulfills its obligations: (i) identification of the promised goods or services in the contract; (ii) determination of whether the promised goods or services are performance obligations including whether they are distinct in the context of the contract; (iii) measurement of the transaction price, including the constraint on variable consideration; (iv) allocation of the transaction price to the performance obligations based on estimated selling prices; and (v) recognition of revenue when (or as) the Company satisfies each performance obligation. The Company evaluates the performance obligations promised in the contract that are based on goods and services that will be transferred to the customer and determines whether those obligations are both (i) capable of being distinct and (ii) distinct in the context of the contract. Goods or services that meet these criteria are considered distinct performance obligations. The Company estimates the transaction price based on the amount expected to be received for transferring the promised goods or services in the contract. The consideration may include fixed consideration or variable consideration. The 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. At the inception of each arrangement that includes variable consideration, the Company evaluates the amount of potential transaction price and the likelihood that the transaction price will be received. The Company utilizes either the most likely amount method or expected value method to estimate the a m Revenue is recognized when, or as, the Company satisfies a performance obligation by transferring a promised good or service to a customer. An asset is transferred when, or as, the customer obtains control of that asset. After contract inception, the transaction price is reassessed at every period end and updated for changes such as resolution of uncertain events. Any change in the overall transaction price is allocated to the performance obligations based on the same methodology used at contract inception. The Company recognizes sales-based royalties or net profit-sharing when the later of (a) the subsequent sale occurs, or (b) the performance obligation to which the sales-based royalty or net profit-sharing has been allocated has been satisfied. 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. Refer to Note 9 (Collaboration and Licensing Arrangements), for further discussion on the Company’s collaborative and licensing arrangements.
RESEARCH AND DEVELOPMENT	n. RESEARCH AND DEVELOPMENT.
STOCK-BASED COMPENSATION	o. STOCK-BASED COMPENSATION. one
CONCENTRATION OF RISK	p. CONCENTRATION OF RISK. The Company sells its product in the United States through an exclusive distributor (its Customer) to SPs. Therefore, its distributor and SPs account for principally 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	q. ROYALTIES.
INCOME TAXES	r. 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
COMPREHENSIVE INCOME	s. COMPREHENSIVE INCOME. available-for-sale
NET INCOME PER COMMON SHARE	t. NET INCOME PER COMMON SHARE. Diluted net income per common share is computed by dividing net income 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 Three Months Ended For the Nine Months Ended 2021 2020 2021 2020 Basic weighted average common shares outstanding 103,196,550 103,535,431 103,470,762 103,452,025 Effect of dilutive securities 4,646,646 2,780,810 4,005,413 2,934,592 Diluted weighted average common shares outstanding 107,843,196 106,316,241 107,476,175 106,386,617 Outstanding common stock equivalents totaling approximately 2.6 million and 5.3 million, were excluded from the calculation of diluted net income per common share for the three and nine months ended September 30, 2021 as their effect would be anti-dilutive. For the three and nine months ended September 30, 2020, approximately 5.4 million and 4.8 million shares of common stock equivalents were excluded from the calculation of diluted net income per common share as their effect would be anti-dilutive.
RECLASSIFICATIONS	u. RECLASSIFICATIONS.
RECENTLY ISSUED ACCOUNTING STANDARDS	v. RECENTLY ISSUED ACCOUNTING STANDARDS. 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)	9 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
Fair Value Measurement Specific to Assets or Liability	Fair Value Measurements at Reporting Date Using (in thousands) Balances Quoted Prices in Significant Significant Cash and cash equivalents: Money market funds $ 38,925 $ 38,925 $ — $ — U.S. Treasuries $ 104,995 $ 104,995 $ — $ — Short-term investments: Short-term bond funds $ 19,956 $ 19,956 $ — $ — Balances Quoted Prices in Significant Significant Cash and cash equivalents: Money market funds $ 15,674 $ 15,674 $ — $ — U.S. Treasuries $ 104,994 $ — $ 104,994 $ — Short-term investments: Short-term bond funds $ 10,041 $ 10,041 $ — $ —
Basic and Dilutive Weighted Average Common Shares	The following table reconciles basic and diluted weighted average common shares: For the Three Months Ended For the Nine Months Ended 2021 2020 2021 2020 Basic weighted average common shares outstanding 103,196,550 103,535,431 103,470,762 103,452,025 Effect of dilutive securities 4,646,646 2,780,810 4,005,413 2,934,592 Diluted weighted average common shares outstanding 107,843,196 106,316,241 107,476,175 106,386,617

Investments (Tables)

Investments (Tables)	9 Months Ended
	Sep. 30, 2021
Investments, Debt and Equity Securities [Abstract]
Summary of Available-for-Sale Investments by Security type	Available-for-sale Estimated Gross Gross Amortized At September 30, 2021: U.S. Treasuries – Cash equivalents $ 104,995 $ — $ — $ 104,995 Short-term bond funds 19,956 — (63 ) 20,019 Total $ 124,951 $ — $ (63 ) $ 125,014 At December 31, 2020: U.S. Treasuries – Cash equivalents $ 104,994 $ 2 $ — $ 104,992 Short-term bond funds 10,041 29 — 10,012 Total $ 115,035 $ 31 $ — $ 115,004
Estimated Fair Values of Available for Sale Securities	The estimated fair values of available-for-sale September 30, 2021 Due in one year or less $ 124,951

Inventory, net (Tables)

Inventory, net (Tables)	9 Months Ended
	Sep. 30, 2021
Inventory Disclosure [Abstract]
Summary of current inventory	Inventory, net consists of the following (in thousands): September 30, 2021 December 31, 2020 Raw materials $ 1,112 $ — Work-in-process 4,847 3,555 Finished goods 991 1,096 Total inventory, net $ 6,950 $ 4,651

Prepaid Expenses and Other Cu_2

Prepaid Expenses and Other Current Assets (Tables)	9 Months Ended
	Sep. 30, 2021
Text Block [Abstract]
Prepaid expenses and other current assets	Prepaid expenses and other current assets consist of the following (in thousands): September 30, 2021 December 31, 2020 Prepaid manufacturing costs $ 2,233 $ 3,328 Prepaid tax 13 1,368 Prepaid insurance 231 1,285 Prepaid subscription fees 689 729 Prepaid research fees 523 453 Prepaid commercialization expenses 90 199 Due from collaborative and licensing arrangements 197 437 Prepaid conference and travel expenses 224 83 Other 228 446 Total prepaid expenses and other current assets $ 4,428 $ 8,328

Operating Leases (Tables)

Operating Leases (Tables)	9 Months Ended
	Sep. 30, 2021
Disclosure of Operating Leases [Abstract]
Lease, Cost	The components of lease expense were as follows (in thousands): For the three For the nine Operating lease cost $ 108 $ 272
Schedule of Supplemental Cash Flow Information Related To Lease	Supplemental cash flow information related to leases was as follows: September 30, 2021 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows $ 29 Right-of-use Operating leases $ 58
Schedule of Supplemental Balance Sheet related To Lease	Supplemental balance sheet information related to leases was as follows: Operating lease right-of-use $ 3,093 Other current liabilities $ 278 Operating lease liabilities, net of current portion 3,973 Total operating lease liabilities $ 4,251 Remaining lease term 9.6 years Discount rate 4.51 %
Lessee, Operating Lease, Liability, Maturity	Remaining payments of lease liabilities as of September 30, 2021 were as follows (in thousands): 2021 (remaining three months) $ 80 2022 492 2023 506 2024 522 2025 537 Thereafter 3,150 Total lease payments 5,287 Less: imputed interest (1,036 ) Total $ 4,251

Property and Equipment, net (Ta

Property and Equipment, net (Tables)	9 Months Ended
	Sep. 30, 2021
Property, Plant and Equipment [Abstract]
Summary of Property and Equipment, net	Property and equipment, net consists of the following (in thousands): September 30, 2021 December 31, 2020 Computer equipment $ 51 $ 51 Furniture and equipment 203 242 Leasehold improvements 939 177 Less: Accumulated depreciation (242 ) (340 ) Total property and equipment, net $ 951 $ 130

Accrued Expenses and Other Li_2

Accrued Expenses and Other Liabilities (Tables)	9 Months Ended
	Sep. 30, 2021
Payables and Accruals [Abstract]
Schedule of Accrued Expenses and Other Liabilities	Accrued expenses and other liabilities consist of the following (in thousands): September 30, 2021 December 31, 2020 Accrued preclinical and clinical trial expenses $ 487 $ 585 Accrued professional fees 1,978 1,884 Accrued compensation and benefits 2,647 3,991 Accrued license fees 9,105 10,373 Accrued purchases 1,483 258 Accrued contributions — 310 Operating lease liability 278 29 Accrued variable consideration 1,439 964 Accrued income tax 335 — Other 110 106 Current accrued expenses and other liabilities 17,862 18,500 Lease liability—non-current 3,973 — Non-current 3,973 — Total accrued expenses and other liabilities $ 21,835 $ 18,500

Stock Compensation (Tables)

Stock Compensation (Tables)	9 Months Ended
	Sep. 30, 2021
Share-based Payment Arrangement [Abstract]
Stock-Based Compensation Expense	For the three and nine months ended September 30, 2021 and 2020, the Company recorded stock-based compensation expense as follows (in thousands): Three months ended Nine months ended 2021 2020 2021 2020 Research and development $ 428 $ 399 $ 1,193 $ 1,239 Selling, general and administrative 1,084 1,079 3,408 3,553 Total stock-based compensation $ 1,512 $ 1,478 $ 4,601 $ 4,792

Basis of Presentation and Sig_4

Basis of Presentation and Significant Accounting Policies - Additional Information (Detail) - USD ($) shares in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Mar. 31, 2021	Dec. 31, 2020
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
Potential equivalent common stock excluded	2.6	5.4	5.3	4.8
Non current investments	$ 0		$ 0			$ 0
Common Stock [Member] | Share Purchase Program [Member]
Summary Of Basis Of Presentation And Significant Accounting Policies [Line Items]
Share repurchase authorized amount					$ 40,000,000

Basis of Presentation and Sig_5

Basis of Presentation and Significant Accounting Policies - Fair Value Measurement Specific to Assets or Liability (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	$ 19,956	$ 10,041
Short-Term Bond Fund [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	19,956	10,041
U.S. Treasuries [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	104,995	104,994
Money Market Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	38,925	15,674
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	19,956	10,041
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | U.S. Treasuries [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	104,995
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	$ 38,925	15,674
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

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	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Weighted Average Number of Shares Outstanding Reconciliation [Abstract]
Basic weighted average common shares outstanding	103,196,550	103,535,431	103,470,762	103,452,025
Effect of dilutive securities	4,646,646	2,780,810	4,005,413	2,934,592
Dilutive weighted average common shares outstanding	107,843,196	106,316,241	107,476,175	106,386,617

Investments - Additional Inform

Investments - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Investments, Debt and Equity Securities [Abstract]
Realized gains losses from available for sale securities	$ 0	$ 0	$ 0	$ 0

Investment - Summary of Availab

Investment - Summary of Available-for-Sale Investments by Security type (Detail) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Net Investment Income [Line Items]
Amortized cost	$ 125,014	$ 115,004
Gross Unrealized Gains	0	31
Gross Unrealized Losses	(63)
Estimated Fair Value	124,951	115,035
U.S. Treasuries – Cash equivalents [Member]
Net Investment Income [Line Items]
Amortized cost	104,995	104,992
Gross Unrealized Gains	0	2
Estimated Fair Value	104,995	104,994
Short-term bond funds [Member]
Net Investment Income [Line Items]
Amortized cost	20,019	10,012
Gross Unrealized Gains		29
Gross Unrealized Losses	(63)
Estimated Fair Value	$ 19,956	$ 10,041

Investment - Estimated Fair Val

Investment - Estimated Fair Values of Available for Sale Securities (Detail) $ in Thousands	Sep. 30, 2021USD ($)
Investments, Debt and Equity Securities [Abstract]
Due in one year or less	$ 124,951

Inventory, net - Summary Of Cur

Inventory, net - Summary Of Current Inventory (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Inventory [Line Items]
Raw materials	$ 1,112
Work-in-process	4,847	$ 3,555
Finished goods	991	1,096
Total inventory, net	$ 6,950	$ 4,651

Prepaid Expenses and Other Cu_3

Prepaid Expenses and Other Current Assets - Prepaid Expenses and Other Current Assets (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Prepaid manufacturing costs	$ 2,233	$ 3,328
Prepaid tax	13	1,368
Prepaid insurance	231	1,285
Prepaid subscription fees	689	729
Prepaid research fees	523	453
Prepaid commercialization expenses	90	199
Due from collaborative and licensing arrangements	197	437
Prepaid conference and travel expenses	224	83
Other	228	446
Total prepaid expenses and other current assets	$ 4,428	$ 8,328

Operating Leases - Operating Le

Operating Leases - Operating Leases (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2021
Disclosure of Operating Leases [Abstract]
Operating lease cost	$ 108	$ 272

Operating Leases - Schedule of

Operating Leases - Schedule of Supplemental Cash Flow Information Related To Lease (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2021USD ($)
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows	$ 29
Right-of-use assets obtained in exchange for lease obligations:
Operating leases	$ 58

Operating Leases -Schedule of S

Operating Leases -Schedule of Supplemental Balance Sheet related To Lease (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Disclosure of Operating Leases [Line Items]
Operating lease right-of-use assets	$ 3,093
Other current liabilities	278	$ 29
Operating lease liabilities, net of current portion	3,973
Total operating lease liabilities	$ 4,251
Remaining lease term	9 years 7 months 6 days
Discount rate	4.51%

Operating Leases -Lessee, Opera

Operating Leases -Lessee, Operating Lease, Liability, Maturity (Detail) $ in Thousands	Sep. 30, 2021USD ($)
Disclosure of Operating Leases [Line Items]
2021 (remaining three months)	$ 80
2022	492
2023	506
2024	522
2025	537
Thereafter	3,150
Total lease payments	5,287
Less imputed interest	(1,036)
Total	$ 4,251

Operating Leases - Additional

Operating Leases - Additional Information (Detail) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021USD ($)	Sep. 30, 2020USD ($)	Sep. 30, 2021USD ($)ft²	Sep. 30, 2020USD ($)
Disclosure of Operating Leases [Line Items]
Finance Lease Obligations | $	$ 0		$ 0
Lessor, Operating Lease, Option to Extend			5 years
Rent expense | $	$ 100	$ 100	$ 300	$ 300
Before agreement of company leased spaces | ft²			7,800
After agreement of company leased spaces | ft²			10,700
Maximum [Member]
Disclosure of Operating Leases [Line Items]
Lessor, Operating Lease, Option to Terminate			7.6
Minimum [Member]
Disclosure of Operating Leases [Line Items]
Lessor, Operating Lease, Option to Terminate			6

Property and Equipment, Net - S

Property and Equipment, Net - Summary Of Property and Equipment, Net (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Less: Accumulated depreciation	$ (242)	$ (340)
Total property and equipment, net	951	130
Computer Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	51	51
Furniture and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	203	242
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 939	$ 177

Accrued Expenses and Other Li_3

Accrued Expenses and Other Liabilities - Schedule of Accrued Expenses and Other Liabilities (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Payables and Accruals [Abstract]
Accrued preclinical and clinical trial expenses	$ 487	$ 585
Accrued professional fees	1,978	1,884
Accrued compensation and benefits	2,647	3,991
Accrued license fees	9,105	10,373
Accrued purchases	1,483	258
Accrued contributions		310
Operating lease liability	278	29
Accrued variable consideration	1,439	964
Accrued income tax	335
Other	110	106
Current accrued expenses and other liabilities	17,862	18,500
Lease liability—non-current	3,973
Non-current accrued expenses and other liabilities	3,973
Total accrued expenses and other liabilities	$ 21,835	$ 18,500

Collaboration and Licensing A_2

Collaboration and Licensing Arrangements - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Collaborative Arrangements [Line Items]
Period of collaboration agreement			10 years
Expenses In Connection With Collaborative Arrangement	$ 4,487,000	$ 3,749,000	$ 11,944,000	$ 12,322,000
DyDo Pharma, Inc [Member]
Collaborative Arrangements [Line Items]
Milestone payments income			0
Revenues	0		2,700,000
Collaborative Arrangement [Member]
Collaborative Arrangements [Line Items]
Milestone payments			2,000,000
Milestone payments income			0	0
Expenses In Connection With Collaborative Arrangement		0		4,200
Revenues	0	$ 0	0	$ 0
Endo Collaboration [Member]
Collaborative Arrangements [Line Items]
Expenses In Connection With Collaborative Arrangement	0		45,000
KYE Pharmaceuticals Collaboration [Member] | Selling, General and Administrative Expenses [Member]
Collaborative Arrangements [Line Items]
Revenues from collaborative arrangements	$ 0		$ 0

Agreements - Additional Informa

Agreements - Additional Information (Detail) $ in Millions	9 Months Ended
	Sep. 30, 2021USD ($)
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 - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Income Tax Disclosure [Line Items]
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	$ 0	$ 0		$ 0
Effective Income Tax Rate Reconciliation, Percent		24.30%	2.80%
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%

Stockholders' Equity (Preferred

Stockholders' Equity (Preferred Stock and Common Stock) - Additional Information (Detail) $ / shares in Units, $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2021USD ($)Vote$ / sharesshares	Jun. 30, 2021shares	Mar. 31, 2021USD ($)shares	Sep. 30, 2021USD ($)Vote$ / sharesshares	Dec. 31, 2020$ / sharesshares
Stockholders Equity [Line Items]
Preferred stock, shares authorized	5,000,000			5,000,000	5,000,000
Preferred stock, par value | $ / shares	$ 0.001			$ 0.001	$ 0.001
Preferred stock, shares outstanding	0			0	0
Common stock, shares authorized	200,000,000			200,000,000	200,000,000
Common stock, par value | $ / shares	$ 0.001			$ 0.001	$ 0.001
Common stock, shares issued	103,153,459			103,153,459	103,781,641
Common stock, shares outstanding	103,153,459			103,153,459	103,781,641
Number of votes entitled for each share of common stock | Vote	1			1
Share Repurchased During The Period Shares	949,746			1,749,746
Average purchase price per share | $ / shares	$ 5.32			$ 5.15
Payment to acquire shares | $	$ 5,100			$ 9,014
Common Stock [Member]
Stockholders Equity [Line Items]
Common stock, shares authorized	200,000,000			200,000,000	200,000,000
Common stock, par value | $ / shares	$ 0.001			$ 0.001	$ 0.001
Common stock, shares issued	103,153,459			103,153,459	103,781,641
Common stock, shares outstanding	103,153,459			103,153,459	103,781,641
Share Repurchased During The Period Shares	950,000	733,000	67,000
Share Purchase Program [Member] | Common Stock [Member]
Stockholders Equity [Line Items]
Share repurchase authorized amount | $			$ 40,000

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

Stock Compensation - Stock-Base

Stock Compensation - Stock-Based Compensation Expense (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation	$ 1,512	$ 1,478	$ 4,601	$ 4,792
Research and Development [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation	428	399	1,193	1,239
Selling, General and Administrative [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation	$ 1,084	$ 1,079	$ 3,408	$ 3,553

Stock Compensation - Additional

Stock Compensation - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Proceeds from exercise of stock options			$ 3,414	$ 693
Stock options to purchase shares of common stock	13,162,504		13,162,504
Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted, expiration Period	7 years	7 years	7 years	7 years
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense related to non-vested stock compensation awards granted under the Plan	$ 600		$ 600
Expected remaining weighted average vesting period			1 year 2 months 26 days
Non-cash stock-based compensation expense	$ 100	$ 100	$ 400	$ 400
Common stock granted	0			30,000
Options to Purchase Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of stock options exercised	941,164	215,097	1,114,494	240,096
Proceeds from exercise of stock options	$ 3,000	$ 600	$ 3,400	$ 700
Common stock unit granted	400,000	10,000	1,030,000	1,005,000
Unrecognized compensation expense related to non-vested stock compensation awards granted under the Plan	$ 8,000		$ 8,000
Expected remaining weighted average vesting period			2 years 1 month 24 days
Non-cash stock-based compensation expense	$ 1,400	$ 1,300	$ 4,200	$ 4,400
Stock options to purchase shares of common stock	7,956,962		7,956,962