Merck discontinues clinical development programs for vibostolimab, favezelimab

Separately, Merck has decided to end the favezelimab clinical development program, and will stop enrollment in the Phase 3 KEYFORM-008 trial evaluating the fixed-dose combination of favezelimab and pembrolizumab in patients with relapsed or refractory classical Hodgkin lymphoma (cHL) whose disease has progressed following prior anti-PD-1 therapy. Patients currently in this trial may continue on therapy until study completion. KEYFORM-008 is the only Phase 3 study in the KEYFORM clinical development program for which results are not available. The company has made this decision after a thorough evaluation of data from the favezelimab clinical program and will prioritize the development of other candidates in its comprehensive and diversified oncology pipeline. This decision is not based on any concerns about the safety of this fixed-dose combination.

Merck is informing study investigators for these clinical trials and advises patients to speak to their study team and physician regarding next steps and treatment options. Data analyses for the Phase 3 trials are ongoing, and the results will be shared with the scientific community, the Company said.

"Following a careful analysis of the data, the decision has been made to discontinue development of these candidates to prioritize other ongoing programs. We are grateful to all the patients, caregivers and investigators for their many contributions that made these studies possible," said Dr. Marjorie Green, senior vice president and head of oncology, global clinical development, Merck Research Laboratories. "We continue to pursue the most promising science with a focus on agents with the greatest potential to improve outcomes for more patients with cancer."