SUPERNUS PHARMACEUTICALS, INC.

Evaluation of Disclosure Controls and Procedures

We maintain disclosure controls and procedures required by Rule 13a-15(e) and 15d-15(e) of the Securities Exchange Act of 1934, as amended, or the Exchange Act. Our disclosure controls and procedures are designed to provide reasonable assurance that the information required to be disclosed by us in the reports we file or submit under the Exchange Act has been appropriately recorded, processed, summarized, and reported within the time periods specified in the Securities and Exchange Commission's rules and forms and that such information is accumulated and communicated to our management, including our CEO and CFO, to allow timely decisions regarding required disclosure.

We conducted an evaluation of the effectiveness of the design and operation of our disclosure controls and procedures as of September 30, 2025, the end of the period covered by this report. Based on that evaluation, under the supervision and with the participation of our management, including our CEO and CFO, we concluded that our disclosure controls and procedures are effective as of September 30, 2025.

Changes in Internal Control over Financial Reporting

Our management, including our CEO and CFO, evaluated changes in our internal control over financial reporting that occurred during the quarter ended September 30, 2025.

During the quarter ended September 30, 2025, the Company completed its acquisition of Sage Therapeutics, Inc. (Sage). Other than the implementation of 1) controls related to the accounting of the Sage Acquisition, 2) integrating the Sage business where certain controls will be evaluated and may change, and 3) the related financial statement reporting, there have been no changes in our internal control over financial reporting that materially affected, or are reasonably likely to materially affect, our internal control over financial reporting.