Patients with metastatic uveal melanomas have a poor prognosis. The targetable BRAF mutation is not present in this subset of melanoma. Response to chemotherapy is poor with no survival benefit. We report a retrospective case series of metastatic uveal melanoma patients treated with single agent and combination immunotherapy.
Retrospective data was retrieved from the Princess Alexandra Hospital and Greenslopes Private Hospital Oncology Units of metastatic uveal melanoma patients treated with immunotherapy. Response rate, progression free survival and overall survival were reviewed.
19 patients were identified, 13 were treated with pembrolizumab and 6 with combination ipilimumab and nivolumab. 7 of the 13 patients who received pembrolizumab had prior ipilimumab monotherapy as it was required to access compassionate access pembrolizumab. Median age was 63. Median follow up was 484 days. All patients had liver involvement except one with a mesenteric lymph node mass and pulmonary metastasis. Median overall survival was 257 days for the ipilimumab and nivolumab combination treatment group and 197 days for the pembrolizumab group. Progression free survival was 196 days for the ipilimumab and nivolumab combination treatment group and 105 days for the pembrolizumab group. Response rate was 0% for the 13 patients treated with pembrolizumab and 50% for the 6 patients treated with combination immunotherapy.
Single agent pembrolizumab demonstrated no clinically meaningful response in patients with metastatic uveal melanoma, consistent with other cases series. However the median survival for patients was significantly longer than expected despite the lack of response. Potentially prior exposure to ipilimumab in the single agent cohort would account for this finding. Even with small numbers, combination therapy would appear to have a clinically significant response rate. These data on combination therapy represent early follow up and the potential for a durable response from combination therapy warrants further investigation.