Single-center experience of PD1 inhibition in metastatic uveal melanoma.

Abstract

87 Background: Metastatic uveal melanoma (MUM) is a rare histology with poor prognosis. Therapies used in cutaneous melanoma with success have limited to no efficacy in uveal melanoma. Limited data exists regarding the efficacy of PD-1 inhibition in this disease. Methods: Patients carrying a diagnosis of MUM that had been treated with any PD1 inhibitor at the Cleveland Clinic were analyzed. Median overall survival from the diagnosis of metastatic disease and from the start of PD-1 inhibition were calculated. RECIST 1.1 criteria were used to assess response to therapy. Results: 10 patients with MUM have been treated with a PD1 inhibitor. Mean age at initiation of PD1 inhibition was 74. Five (50%) were female. Median time from initial diagnosis to metastatic disease was 67 months (range, 5-204). All 6 patients with a genetic profiling result available were classified as poor risk either by cytogenetics or gene expression profiling. Median overall survival from diagnosis of metastatic disease was 24 months (range, 9-46). Six patients had also been treated with ipilimumab, 4 had prior treatment, 1 had PD-1 prior to ipilimumab, and one had concurrent treatment with combination ipilimumab/nivolumab. Adjunct local radiation occurred in 6 patients: 5 of the liver (4 embolization, 1 SBRT), one of osseous metastases. Median time on PD1 treatment was 2 months (range, 1-6). Two patients had SD, 6 PD, 3 have not yet been reevaluated. Median survival from initiation of PD1 inhibition was 9 months (range, 7-12). Adverse events were as expected from published experiences with PD-1 inhibition. All patients with median survival from initial diagnosis of metastatic disease over one year received both PD-1 and CTLA-4 inhibition as well as radiation. Conclusions: In this single center experience, no patients had tumor response to PD-1 inhibition. Combination therapies may be worth exploring in the treatment of MUM.