71691 - Long-term overall survival after isolated liver perfusion with melphalan in patients with isolated liver metastases of uveal melanoma (SCANDIUM trial)

Introduction Uveal melanoma, a rare subtype of melanoma, often spreads to the liver, resulting in poor prognosis with limited treatment options. The SCANDIUM trial investigated the efficacy of isolated hepatic perfusion (IHP) with high-dose melphalan compared to investigators choice of treatment for patients with liver metastases from uveal melanoma. We have previously reported superior response rates and progression-free survival with IHP, although overall survival (OS) at 24 months did not reach statistical significance. Here we present extended OS follow-up data. Method In this phase III trial, treatment-naïve nordic patients with isolated liver metastases from uveal melanoma were randomized between 2013 and 2021 to receive either IHP or best alternative care in a 1:1 ratio, with no crossover allowed. All IHP treatments were performed at Sahlgrenska University hospital. Result Patients were randomized to IHP (n=43) or control (n=44). In the IHP group, 89% underwent the procedure. The control group received chemotherapy (49%), immunotherapy (39%) or localized treatment interventions (9%). The overall response rate in the IHP group was 40%, with a median response duration of 13.7 months. At a minimum 36-month follow-up, the 3-year OS rate was 18.6% in the IHP group compared to 9.1% in the control group (p=0.23). The 5-year OS rate was 16.3% versus 6.8%, respectively. Median OS was 21.4 months in the IHP group and 17.3 months in the control group (p=0.11, log-rank test). Discussion Extended analysis of the SCANDIUM trial confirms the long-term efficacy of one-time IHP treatment compared to best alternative care for isolated liver metastases from uveal melanoma.