Exhibit 99.1 Collegium Reports Record Fourth Quarter and Full-Year 2023 Financial Results – Generated Record Quarterly and Full-Year Net Revenue of $149.7 Million and $566.8 Million – – Achieved Quarterly and Full-Year GAAP Net Income of $31.9 Million and $48.2 Million – – Delivered Record Quarterly and Full-Year Adjusted EBITDA of $104.2 Million and $367.0 Million – – Ended 2023 with Cash, Cash Equivalents and Marketable Securities of $310.5 Million – – Conference Call Scheduled for Today at 4:30 p.m. ET – ...