SUPERNUS PHARMACEUTICALS, INC.

This Proxy Statement is furnished with the attached Notice of Annual Meeting on or about April 30, 2026, to each stockholder of record of Supernus Pharmaceuticals, Inc. (Supernus or the Company) as of the close of business on April 29, 2026 (the “Record Date”), in connection with the solicitation of proxies by the Board of Directors to be voted at the Annual Meeting of Stockholders (Annual Meeting) of the Company to be held virtually via a webcast on June 18, 2026, at 10:00 A.M. Eastern Daylight Time, and at any adjournment or adjournments thereof for the purposes stated below.

Only stockholders of record as of the close of business on the Record Date will be entitled to vote on all matters presented for vote at the Annual Meeting. At the close of business on April 29, 2026, the total number of shares of our common stock (Common Stock) outstanding was 58,039,721 shares. Each share of Common Stock will be entitled to one vote per share on all business to come before the Annual Meeting.