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

BACKGROUND: 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.
METHODS: Advanced melanoma patients who failed to previous treatment lines were treated with pembrolizumab 2 mg/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.
RESULTS: 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 14.0 months; 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 (3.5 m+ to 20.4 m+). 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.
CONCLUSION: 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.