X0306 4 2022-12-22 0001267565 COLLEGIUM PHARMACEUTICAL, INC COLL 0001448914 Heffernan Michael Thomas C/O COLLEGIUM PHARMACEUTICAL, INC. 100 TECHNOLOGY CENTER DRIVE STOUGHTON MA 02072 1 0 0 0 Common Stock 2022-12-22 4 M 0 237 16.150 A 28260 D Common Stock 2022-12-22 4 S 0 237 23.0 D 28023 D Common Stock 2022-12-23 4 M 0 4989 16.150 A 33012 D Common Stock 2022-12-23 4 S 0 4989 23.0 D 28023 D Common Stock 2022-12-27 4 M 0 15995 16.150 A 44018 D Common Stock 2022-12-27 4 S 0 15995 23.63 D 28023 D Common Stock 2022-12-27 4 M 0 3820 16.150 A 31843 D Common Stock 2022-12-27 4 S 0 3820 24.16 D 28023 D Stock Option (Right to Purchase) 16.150 2022-12-22 4 M 0 237 0 D 2026-01-20 Common Stock 237 24804 D Stock Option (Right to Purchase) 16.150 2022-12-23 4 M 0 4989 0 D 2026-01-20 Common Stock 4989 19815 D Stock Option (Right to Purchase) 16.150 2022-12-27 4 M 0 15995 0 D 2026-01-20 Common Stock 15995 3820 D Stock Option (Right to Purchase) 16.150 2022-12-27 4 M 0 3820 0 D 2026-01-20 Common Stock 3820 0 D The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on November 10, 2022. The price reported in column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $23.00 to $23.03, 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 (the "SEC"), upon request, full information regarding the number of shares sold at each separate price within the range set forth in footnote (2). The price reported in column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $23.00 to $23.99, inclusive. The reporting person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the SEC, upon request, full information regarding the number of shares sold at each separate price within the range set forth in footnote (3). The price reported in column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $24.00 to $24.25, inclusive. The reporting person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the SEC, upon request, full information regarding the number of shares sold at each separate price within the range set forth in footnote (4). The option, initially representing a right to purchase a total of 109,005 shares, is fully vested and exercisable. /s/ Colleen Tupper as Attorney-In-Fact For Michael T. Heffernan 2022-12-27