X0508 4 2026-03-05 0 0001356576 SUPERNUS PHARMACEUTICALS, INC. SUPN 0001256088 GEMAYEL GEORGES C/O SUPERNUS PHARMACEUTICALS, INC., 9715 KEY WEST AVENUE ROCKVILLE MD 20850 1 0 0 0 0 Common Stock 2026-03-05 4 S 0 10000 53.71 D 28159 D Common Stock 2026-03-06 4 M 0 7905 25.30 A 36064 D Common Stock 2026-03-06 4 S 0 8787 53 D 27277 D Director Stock Option (Right to Buy) 25.30 2026-03-06 4 M 0 7905 0 D 2018-02-24 2027-02-24 Common Stock 7905 0 D The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $53.50 to $54.15. The Reporting Person undertakes to provide to Supernus Pharmaceuticals, Inc. ("Supernus"), any security holder of Supernus, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote to this Form 4. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $53.00 to $53.03. The Reporting Person undertakes to provide to Supernus, any security holder of Supernus, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote to this Form 4. /s/ Timothy C. Dec, as attorney-in-fact 2026-03-09