From March 2016 to November 2019 mUM patients were included in the prospective Treat20Plus study and tumor was analyzed via a comprehensive molecular tumor analysis program...We documented a minor response in one patient, a mixed response in 2, and a stable disease in 9. One patient with 459 somatic mutations and a MBD4 mutation had a partial durable response under Nivolumab. The median duration of the clinical benefit was 10 months (6-17). Median PFS was 3.33 months (95% CI: 0-7.21).