Durability of response in metastatic melanoma patients after combined treatment with radiation therapy and ipilimumab

We previously reported a prospective trial evaluating the safety and efficacy of combining ipilimumab and radiation therapy in patients with metastatic melanoma. Herein, we provide a long-term update on patients with complete response (CR) or partial response (PR). We continued to follow these patients with serial imaging including computed tomography, PET or MRI. Two of the three patients with CR are still alive and without evidence of melanoma but with chronic treatment-induced hypophysitis. The third patient died of hepatocellular carcinoma, but with no evidence of melanoma. Among the three patients with PR, two achieved CR after pembrolizumab monotherapy. This long-term follow up reveals the striking durability of the CRs, which appears to correlate with a grade 2–3 hypophysitis.