Merck provided an update on the open-label arm of the non-registrational Phase 2 KeyVibe-002 trial. KeyVibe-002 is evaluating MK-7684A, a coformulation of vibostolimab, an anti-TIGIT therapy, and pembrolizumab (KEYTRUDA(R)), Merck's anti-PD-1 therapy, with or without docetaxel for the treatment of patients with metastatic non-small cell lung cancer (NSCLC) with progressive disease after treatment with immunotherapy and platinum-doublet chemotherapy. KeyVibe-002, a partially blinded study, was designed with two primary objectives: 1) to evaluate the efficacy of MK-7684A alone compared with docetaxel, a standard of care; and 2) in a blinded assessment, evaluate the efficacy of adding MK-7684A to docetaxel compared with docetaxel alone.

Results from the open-label arm of the study evaluating MK-7684A alone showed that the coformulation did not reach statistical significance for the primary endpoint of progression-free survival (PFS) and was numerically less effective compared with docetaxel. Merck is notifying study investigators that patients in this arm of the study should be switched to a standard of care, unless their physician considers the patient is benefitting from MK-7684A alone. The blinded arms of the study will continue to further evaluate MK-7684A with docetaxel versus docetaxel alone.

The safety profile of MK-7684A was consistent with that observed for vibostolimab and pembrolizumab in previously reported studies, with no new safety signals observed. Results will be presented at an upcoming medical meeting once further data from the blinded study arms are available. Merck has an extensive clinical development program evaluating the safety and efficacy of MK-7684A alone and in combination with other agents in over 4,000 patients.

Ongoing Phase 3 studies in lung cancer include KeyVibe-003, KeyVibe-006, KeyVibe-007 and KeyVibe-008, as well as KeyVibe-010 in melanoma.