X0508 4 2025-08-13 0001267565 COLLEGIUM PHARMACEUTICAL, INC COLL 0001746251 Dreyer Scott C/O COLLEGIUM PHARMACEUTICAL, INC. 100 TECHNOLOGY CENTER DRIVE STOUGHTON MA 02072 0 1 0 0 EVP & Chief Commercial Officer 1 Common Stock 2025-08-13 4 M 0 4861 21.34 A 108474 D Common Stock 2025-08-13 4 S 0 4861 38.0335 D 103613 D Stock Option (Right to Purchase) 21.34 2025-08-13 4 M 0 4861 0 D 2030-02-05 Common Stock 4861 16389 D The transactions reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 28, 2024. The price reported in column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $38.00 to $38.10, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the U.S. 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. The option is fully vested and exercisable. /s/ Colleen Tupper as Attorney-In-Fact For Scott Dreyer 2025-08-15