Combined low-dose ipilimumab and pembrolizumab after sequential ipilimumab and pembrolizumab failure in advanced melanoma

With the wide use of anti-PD-1 therapy, an increasing number of patients progress under treatment. Combined immunotherapy with anti-CTLA-4 and anti-PD-1 antibodies induces higher response rates as first-line treatment in comparison to single-agent therapy, however, with substantial toxicity since the combination of ipilimumab (3 mg/kg) and nivolumab (1 mg/kg) induced 55% grade 3/4 treatment-related adverse events and treatment discontinuation rates of 39%. In this case series, we investigated the efficacy and toxicity of the combined immunotherapy with low-dose ipilimumab (1 mg/kg) plus pembrolizumab (2 mg/kg) in patients with metastatic melanoma with progressive disease under sequential monotherapy with both agents. All patients had received at least three lines of treatment, 78% of patients were M1c, and 67% had brain metastases. Stable disease was observed in 3 out of 9 patients with a median overall survival of 8 months after double checkpoint inhibition. No treatment-related grade 3/4 adverse events occurred, and none of the patients needed to discontinue the treatment due to toxicity. Further trials are needed to investigate combined immunotherapy as rescue treatment in heavily pre-treated melanoma patients to find optimal dosage in regard to outcome and toxicity. (C) 2016 Elsevier Ltd. All rights reserved.