A phase III multi-institutional randomized study of immunization with the gp100: 209–217(210M) peptide followed by high-dose IL-2 compared with high-dose IL-2 alone in patients with metastatic melanoma

Abstract

CRA9011 Background: In a phase II study, 13 (42%) of 31 patients with metastatic melanoma receiving high-dose (HD) IL-2 plus gp100:209–217(210M) peptide experienced objective responses (S.A. Rosenberg, et al, Nature Medicine 4: 321–327, 1998). Other studies showed a lower response rate (RR) but no randomized studies have been done. Methods: A prospective randomized phase III trial was conducted at 21 centers with 185 patients. Eligibility: stage IV or locally advanced stage III cutaneous melanoma, HLA A0201, no brain metastases, eligible for HD IL-2, and no previous HD IL-2 or gp100:209–217(210M). Arm 1 received HD IL-2 alone (720,000 IU/kg/dose) and Arm 2 gp100:209–217(210M) peptide + Montanide ISA followed by HD IL-2. The primary objective was clinical response. Secondary objectives were toxicity, disease free/progression free survival, immunologic response and quality of life. Central HLA typing, pathology review, and blinded response assessment were done at the NIH. Central data monitoring was done by The EMMES Corp. and a Data Safety Monitoring Board. Results: Numbers of patients enrolled, treated, and evaluable for response in Arm 1 were 94, 93, and 93 respectively; in Arm 2 91, 86, and 86. Toxicities were consistent with HD IL-2 ± vaccine. Investigator assessed RR showed significant improvement in overall RR for Arm 2=22.1% vs 9.7% (P=0.0223, Chi-Square) and progression free survival (PFS) in favor of Arm 2=2.9 months (1.7–4.5) vs 1.6 (1.5–1.8) (P=0.0101). Median overall survival favors Arm 2=17.6 months (11.8–26.6) vs 12.8 (8.7–16.3) (P=0.0964). Blinded response review is ongoing. Conclusions: RR and PFS were superior with peptide vaccine and HD IL-2 compared to HD IL-2 alone. This represents the first evidence of clinical benefit of vaccination in patients with melanoma. [Table: see text]