X0508 4 2025-08-15 0001267565 COLLEGIUM PHARMACEUTICAL, INC COLL 0001276038 SANTINI GINO C/O COLLEGIUM PHARMACEUTICAL, INC. 100 TECHNOLOGY CENTER DRIVE STOUGHTON MA 02072 1 0 0 0 0 Common Stock 2025-08-15 4 M 0 15000 13.45 A 100447 D Common Stock 2025-08-15 4 S 0 5405 37.1912 D 95042 D Stock Option (Right to Purchase) 13.45 2025-08-15 4 M 0 15000 0 D 2025-09-10 Common Stock 15000 0 D The price reported in column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $37.17 to $37.31, 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. Exhibit 24.1 - Power of Attorney /s/ Colleen Tupper as Attorney-in-Fact for Gino Santini 2025-08-19