Pembrolizumab for advanced melanoma: experience from the Spanish Expanded Access Program

Abstract

The programmed death (PD-1) inhibitor pembrolizumab has been recently approved for the treatment of advanced melanoma. We evaluated the clinical activity of pembrolizumab in melanoma patients treated under the Spanish Expanded Access Program. Advanced melanoma patients who failed to previous treatment lines were treated with pembrolizumab 2mg/kg every three weeks. Patients with brain metastases were not excluded if they were asymptomatic. Data were retrospectively collected from 21 centers in the Spanish Melanoma Group. Sixty-seven advanced melanoma patients were analyzed. Most patients were stage M1c (73.1%), had high LDH levels (55.2%) and had ECOG PS 1 or higher (59.7%). For cutaneous melanoma patients, median overall survival was 14.0months; the 18-month overall survival rate was 47.1%. Overall response rate was 27%, including three patients with complete responses (6.5%). Median response duration was not reached, with 83.3% of responses ongoing (3.5m+ to 20.4m+). From ten patients included with brain metastases, four (40%) had an objective response, two (20%) of them achieved a complete response. Significant prognostic factors for overall survival were LDH level, ECOG PS and objective response. There were no serious adverse events. Although this was a heavily pretreated cohort, pembrolizumab activity at the approved dose and schedule was confirmed in the clinical setting with long-term responders, also including patients with brain metastases.