In the study, (1) 107 eligible patients with completely resected, high-risk cutaneous melanoma were randomly assigned 2:1 (stratified by stage) to receive mRNA-4157 in combination with pembrolizumab or pembrolizumab alone. mRNA-4157 (1mg) was administered intramuscularly every 3 weeks for a total of 9 doses and pembrolizumab (200mg) intravenously was given every 3 weeks for up to 18 cycles. Safety was evaluated as a secondary endpoint. Recurrence free survival (RFS) in the overall intention-to-treat population was the primary end point. The primary analysis for RFS was specified to occur after all patients completed a minimum of 12 months on study and at least 40 RFS events were observed.
After 18 months, the patients who received the adjuvant therapy with the mRNA vaccine in combination with pembrolizumab had a 44% lower risk of death or relapse compared with those in the pembrolizumab-only group, without an increase in clinically meaningful adverse events. A phase III study will be initiated in patients with melanoma.
“It’s the best proof-of-principle that the field could have,” stated oncologist Ryan Sullivan, who was involved in the trial, run by the US pharmaceutical company Moderna. “If this was a negative trial, it would have been a disaster.”