Exhibit 99.1 Collegium Reports First Quarter 2024 Financial Results – Generated Q1’24 Net Revenue of $144.9 Million – – Delivered Q1’24 Record Belbuca® Revenue of$50.7 Million; Total Prescriptions Up 4.2% Year-over-Year – – Achieved Q1’24 GAAP Net Income of $27.7 Million vs. Q1’23 GAAP Net Loss of$(17.4) Million – – Delivered Q1’24 Adjusted EBITDA of $92.4 Million, Up 5$35.0 Million Accelerated Share Repurchase Program – – Reaffirmed Full-Year 2024 Guidan ...