Aims: We report updated survival and clinical activity in initially enrolled cohorts and activity by BRAF MT status in a phase I trial of concurrent and sequenced NIVO + IPI. Methods: MEL patients (n=53) with ≤3 prior therapies received concurrent NIVO + IPI (i.v.), every 3 weeks for 4 doses, followed by NIVO every 3 weeks for 4 doses. At week 24, NIVO + IPI continued every 12 weeks for 8 doses in patients with disease control and no dose-limiting toxicity. Tumour responses were evaluated by World Health Organisation (WHO) and immune-related criteria.
Results: Patient characteristics included 55% with stage M1c on study entry and 45% with prior systemic therapy. On concurrent therapy cohorts, across doses, 1- and 2-years overall survival (OS) rates were 85% and 79%, aggregate clinical activity rate (ACAR) was 72% with more complete responses 9/53 (17%) compared to previous reports. ACAR among patients with BRAF mutant status was 67% (8/12) and 72% (28/39) among BRAF wildtype. By week 36, 42% demonstrated ≥80% tumour reduction. Median duration of response (DOR) was not reached. Of 22 pts with objective response, 20 (91%) had DOR ≥24 wk (range: 31, 141). Treatment-related adverse events were as reported previously: grade 3-4, 62% of patients; most common: increased lipase(19%) and AST (13%). Data for sequenced cohorts showed a median OS of 13 months and ACAR of 52%; there was similar activity in patients regardless of tumour BRAF MT status. Conclusions: Concurrent NIVO + IPI therapy showed encouraging survival and a manageable safety profile in advanced MEL patients. Responses were observed regardless of BRAF MT status and were durable in the majority of patients. Phase 2 and 3 trials investigating concurrent NIVO+IPI in MEL patients are currently underway and the NIVO+IPI combination is also being investigated in other tumour types.