Correlation of immune response with clinical outcomes in melanoma patients receiving adjuvant therapy of pegylated interferon alpha-2b combined with gp100 peptide vaccine.

3026 Background: Vaccination using tumor-associated antigen peptides alone has shown limited clinical benefit. Preclinical studies have demonstrated interferon-alpha promotes vaccine-induced tumor-specific T-cell responses. Our randomized 3-arm study explored the optimal biological dosing (OBD) schedule of pegylated IFN-alpha-2b (PEG-IFN) when combined with gp100 vaccine in patients (pts) with resected melanoma, while demonstrating safety with acceptable toxicity. Methods: After definitive surgical resection, melanoma pts were randomized into 1 of 3 PEG-IFN arms [Induction Phase (6 mcg/kg/wk)/Maintenance Phase (3 mcg/kg/wk)]: (1) Arm 1: 4 wk/20 wk; (2) Arm 2: 8 wk/16 wk; (3) Arm 3:12 wk/12 wk. All pts were vaccinated with gp100209-2M every 3 wk x 8. Toxicity and gp100-specific T-cell responses were assessed every 3 wk. Results: 30 pts (8 stage II, 22 stage III) were enrolled and treated in 3 arms (11 Arm 1, 9 Arm 2, 10 Arm 3). All 3 dosing schedules were found to be safe and well tolerated. Despite PEG-IF...