Merck Ends Development of Immunotherapy Drugs Vibostolimab and Favezelimab Amid Late-Stage Failures

Merck has decided to halt the development of vibostolimab for non-small cell lung cancer (NSCLC) after the treatment, in combination with Keytruda, failed to demonstrate significant efficacy in late-stage trials. The decision follows the Phase III KeyVibe-003 and KeyVibe-007 trials, which did not meet the set objectives for overall survival, prompting an independent Data Monitoring Committee to recommend their termination[1][2]. Additionally, these studies reported a higher incidence of immune-related adverse events when vibostolimab was combined with Keytruda compared to Keytruda alone[1][2]. This discontinuation is part of Merck's strategic reevaluation of its oncology pipeline[2].