Ipilimumab in the treatment of uveal melanoma: The Memorial Sloan-Kettering Cancer Center experience.

Abstract

8549 Background: Ipilimumab (ipi) is an antibody that blocks cytotoxic T-lymphocyte antigen-4 (CTLA-4) and improves overall survival in patients (pts) with metastatic melanoma. Uveal melanoma (UM) is a rare and biologically unique disease subtype with no known effective systemic therapy. Ipi has proven efficacy in cutaneous melanoma (CM), but limited data exists regarding its activity in UM. We reviewed our single-institutional experience with ipi in advanced UM. Methods: After IRB approval, the MSKCC melanoma database was queried for patients with metastatic UM treated with ipi between 03/08-01/12. Radiographic response by RECIST and immune-related response criteria (irRC) was assessed by a single radiologist blinded to clinical outcomes. Immune-related adverse events (irAEs), survival and absolute lymphocyte count (ALC) were also evaluated. Results: 20 pts were identified: the median age was 61yrs (range 46-83), 55% were male, 85% had liver metastases, 60% had elevated LDH, and pts reported a median of 1 prior therapies (range 0-5). Pts received a median of 4 doses (range 1-16) of ipi. Response rates (RR) by irRC at 12 and 24 wks are listed below. Among pts with stable disease (SD) at 12 wks, the median time to progression was 30.6 wks (range 19.6-83), with one partial response (PR) occurring after 24 wks (overall RR 10%). Responses were observed in lung, liver and peritoneal metastases. Pts with an ALC ≥ 1.0 at 7 wks had a trend toward a higher clinical benefit (CB= CR + PR + SD) than pts with ALC < 1.0 (5/12 [42%] vs 0/5 [0%]; p= .09), consistent with prior studies in CM. To date, median survival for the group is 8.6 mos (95% CI, 3.5-NR), with two ongoing PRs (3+ yrs and 24+ wks). Reported irAEs include rash/pruritis (10/20), hepatitis (1/20), colitis (1/20), pancreatitis (1/20) and uveitis (1/20). Conclusions: Ipi has potential for benefit in pts with advanced UM; RR and irAE rates are similar to those observed in pts with advanced CM. Further evaluation of ipi in the treatment of UM, including identification of potential biomarkers of CB, is warranted. [Table: see text]