SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM10-Q (Mark One)☒QUARTERLY REPORT PURSUANT TO SECTION13 OR 15(d)OF THE SECURITIESEXCHANGE ACT OF 1934 For the quarterly period endedMarch 31, 2025 ☐TRANSITION REPORT PURSUANT TO SECTION13 OR 15(d)OF THE SECURITIESEXCHANGE ACT OF 1934 For the transition period fromtoCommission File Number:001-35518 SUPERNUS PHARMACEUTICALS,INC. (Exact name of registrant as specified in its charter) (301)838-2500(Registrant’s telephone number, including area code) Indicate by check mark whether the registrant: (1)has filed all reports required to be filed by Section13 or 15(d)of the SecuritiesExchange Act of 1934 during the preceding 12months (or for such shorter period that the registrant was required to file such reports), Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submittedpursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the ☒YesNo☐ Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smallerreporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period forcomplying with any new or revised financial accounting standards provided pursuant to Section13(a)of the Exchange Act.o Indicate by check mark whether the registrant is a shell company (as defined in Rule12b-2 of the Exchange Act).☐Yes☒NoSecurities registered pursuant to Section12(b)of the Exchange Act PARTI — FINANCIAL INFORMATIONItem1. Unaudited Condensed Consolidated Financial StatementsCondensed Consolidated Balance SheetsCondensed Consolidated Statements ofEarnings (Loss)Condensed Consolidated Statements of Comprehensive Earnings (Loss)Condensed Consolidated Statements of Changes in Stockholders' EquityCondensed Consolidated Statements of Cash FlowsNotes to Condensed Consolidated Financial StatementsItem2. Management’s Discussion and Analysis of Financial Condition and Results of OperationsItem3. Quantitative and Qualitative Disclosures about Market RiskItem4. Controls and ProceduresPARTII — OTHER INFORMATIONItem1. Legal ProceedingsItem1A. Risk FactorsItem2. Unregistered Sales of Equity Securities and Use of ProceedsItem3. Defaults Upon Senior SecuritiesItem4. Mine Safety DisclosuresItem5. Other InformationItem6. ExhibitsSIGNATURES Supernus Pharmaceuticals,Inc.Condensed Consolidated Balance Sheets(in thousands, except share data) Supernus Pharmaceuticals,Inc.Condensed Consolidated Statements of Changes in Stockholders’ Equity Supernus Pharmaceuticals,Inc.Condensed Consolidated Statements of Cash Flows(in thousands) Table of Contents Supernus Pharmaceuticals,Inc.Notes to Condensed Consolidated Financial Statements (unaudited) 1.Business Organization Supernus Pharmaceuticals, Inc. (the Company, seeConsolidationin Note 2,Summary of Significant Accounting Policies) is abiopharmaceutical company focused on developing and commercializing products for the treatment of central nervous system (CNS)diseases. The Company's diverse neuroscience portfolio includes approved treatments for attention-deficit hyperactivity disorder(ADHD), dyskinesia in Parkinson's Disease (PD) patients receiving levodopa-based therapy, hypomobility in PD, epilepsy, migraine, The Company haseightcommercial products that it markets: Qelbree, GOCOVRI, Oxtellar XR, Trokendi XR,APOKYN, XADAGO, MYOBLOC and ONAPGOONAPGO (apomorphine hydrochloride) injection as the first and only subcutaneous apomorphine infusion device for the treatment ofmotor fluctuations in adults with advanced PD. ONAPGO was launched in April 2025.®®® 2.Summary of Significant Accounting Policies The Company’s unaudited condensed consolidated financial statements have been prepared in accordance with therequirements of the U.S. Securities and Exchange Commission (SEC) for interim financial information. As permitted under GenerallyAccepted Accounting Principles in the United States (U.S. GAAP), certain notes and other information have been omitted from the interim unaudited condensed consolidated financial statements presented in this Quarterly Report on Form10-Q. Therefore, theseunaudited condensed consolidated financial statements should be read in conjunction with the Company’s most recent Annual Reporton Form10-K, for the year ended December31, 2024, filed with the SEC. In management’s opinion, the unaudited condensed consolidated financial statements include all normal and recurringadjustments necessary for a fair presentation of the Company’s financial position, results of operations, and cash flows. The results of The Company, which is primarily located in the U.S., operates inoneoperating segment. Reclassifications The prior yea