Immunocore presents three-year overall survival data from KIMMTRAK Phase 3 trial

Immunocore announces that the three-year overall survival data from the KIMMTRAK Phase 3 trial in previously untreated HLA-A*02:01 positive patients with metastatic uveal melanoma has been published in The New England Journal of Medicine, and presented as a late breaking abstract in a mini oral session at the European Society for Medical Oncology Congress 2023. In the Phase 3 trial follow up – the longest of any randomized trial for metastatic uveal melanoma – the three-year OS rate was 27% in the KIMMTRAK arm, versus 18% in the control arm. The median OS was 21.6 months on KIMMTRAK, versus 16.9 months on investigator’s choice. The OS Hazard Ratio avored KIMMTRAK, HR=0.68, over investigator’s choice. Overall response rate remained in favor of KIMMTRAK when compared with the control arm and the median duration of response for KIMMTRAK patients was 11.1 months. The rate of disease control was also higher in the KIMMTRAK arm versus the control arm. Over half of all patients treated with KIMMTRAK were treated beyond initial radiographic progression. The trial evaluated circulating tumor DNA clearance as a predictor of overall survival. ctDNA clearance on KIMMTRAK occurred in 37% of evaluable patients and was associated with longer OS. No new adverse events related to long-term KIMMTRAK treatment were observed. The rate of discontinuation due to treatment-related AEs continued to be lower in the KIMMTRAK arm than for the control arm. There were no treatment-related deaths. In a separate poster at the Congress, an analysis of the role of subsequent therapy from the Phase 3 trial in first-line mUM patients confirmed that the survival benefit mostly comes from KIMMTRAK treatment rather than subsequent therapy. A further poster included an analysis from the Phase 1b study in previously treated metastatic cutaneous melanoma patients, demonstrating the safety and activity of KIMMTRAK by BRAF mutation status. A third poster investigated the reprogramming effect of KIMMTRAK on immunosuppressive M2 macrophages from Phase 2 unresectable or metastatic uveal melanoma patients, as well as in vitro.