72206 - Overall Survival after Isolated Hepatic Perfusion in Combination with Ipilimumab and Nivolumab in Patients with Uveal Melanoma (SCANDIUM II trial)

Abstract Introduction Uveal melanoma (UM) is a rare disease with a propensity for liver metastases and a poor prognosis. Isolated hepatic perfusion (IHP) using high-dose melphalan has demonstrated a 40% response rate in patients with liver metastases from UM, while the combination of ipilimumab 3 mg/kg and nivolumab 1 mg/kg (IPI3/NIVO1) yields response rates of 11-18%. However, the impact on overall survival (OS) of combining these treatments is unknown. Method This multicenter, open-label, randomized, controlled phase Ib trial enrolled patients with liver-dominant metastatic UM, randomized to receive either IHP with melphalan 1 mg/kg followed by combination immunotherapy (four cycles of IPI3/NIVO1) (Arm A) or one cycle of IPI3/NIVO1 before IHP followed by three cycles of IPI3/NIVO1 (Arm B). The primary endpoint was safey and has been reported previously, here we present data on overall survival. Result Eighteen patients were included, with 9 in each arm. Seventy-eight percent were treatment-naïve, and 72% had isolated liver metastases. Three patients did not undergo planned IHP. The overall response rate was 38%, with 57% in Arm A and 22% in Arm B, and a median response duration of 11.9 months. At a minimum 18-month follow-up, overall survival was 50%, with 56% in Arm A and 44% in Arm B. Median OS was 18.2 months in Arm A and 17.2 months in Arm B. Discussion The numerically higher response rate in Arm A warrants a randomized study designed to detect differences between IPI/NIVO with or without IHP.