Single Institution Experience of Ipilimumab 3 mg/kg with Sargramostim (GM-CSF) in Metastatic Melanoma

Abstract

Ipilimumab, 10 mg/kg with sargramostim (GM-CSF; GM), improved overall survival (OS) and safety of patients with advanced melanoma over ipilimumab in a randomized phase II trial. The FDA-approved dose of ipilimumab of 3 mg/kg has not been assessed with GM (IPI-GM). Consecutive patients treated with IPI-GM at a single institution were reviewed. Treatment included ipilimumab every 3 weeks × 4 and GM, 250-μg s.c. injection days 1 to 14 of each ipilimumab cycle. Efficacy, clinical characteristics, toxicities, and blinded radiology review of tumor burden were evaluated. Thirty-two patients were identified with 25 (78%) having immune-related response criteria (irRC) measurable disease and 41% with central nervous system metastases. A total of 88.6% of GM doses were administered. Response rate by irRC and disease control rate at 12 weeks were 20% and 44%, respectively (median follow-up 37 weeks). Immune-related adverse events (irAE) were observed in 10 (31.3%) patients, with 3 (9.4%) grade 3 events. Patients with grade 3 irAEs had prior autoimmunity, advanced age, and poor performance status. The median OS from first dose of ipilimumab was 41 weeks. Ipi-GM treatment is feasible and in this poor-risk advanced melanoma population, efficacy appeared similar but safety appeared improved relative to historical ipilimumab alone.