Safety and clinical activity of ipilimumab in melanoma patients with brain metastases: retrospective analysis of data from a phase 2 trial.

Melanoma has a high propensity to metastasize to the brain, and this is often responsible for treatment failure in patients with advanced disease. Melanoma patients with brain metastases are usually excluded from clinical trials because of their expected survival of approximately 5 months. A growing body of evidence suggests that ipilimumab, a human monoclonal antibody that blocks cytotoxic T-lymphocyte antigen-4, has activity against melanoma brain metastases. We conducted a retrospective analysis of data from a phase II study of ipilimumab in advanced melanoma patients. Twelve of 115 patients randomized in the parent trial had stable brain metastases at baseline, as identified by an Independent Review Committee, and were evaluated for efficacy. Two of the 12 patients achieved a partial response and three had stable disease. Both patients with a partial response and one with stable disease were alive at the last follow-up, with survival time of more than 4 years. The median overall survival of the 12 patients was 14 months (range: 2.7-56.4+). An additional four patients with stable brain metastases at baseline were identified by a secondary Independent Review Committee reviewer, and were evaluated for safety. Central nervous system-related adverse events of grade 3-4, specifically cerebral edema and convulsion/seizure, occurred in two of 16 patients. Although the present study is limited by the fact that it is a retrospective analysis of a small number of patients, the results provide further evidence for the safety and efficacy of ipilimumab in melanoma patients with stable brain metastases.