Merck announced the discontinuation of the vibostolimab and pembrolizumab coformulation arm of the Phase 3 KeyVibe-010 trial.

The trial is evaluating the investigational coformulation of vibostolimab, an anti-TIGIT antibody, and pembrolizumab (KEYTRUDA), Merck’s anti-PD-1 therapy, compared to KEYTRUDA alone, as adjuvant treatment for patients with resected high-risk melanoma (Stage IIB-IV).

At a pre-planned analysis, data showed that the primary endpoint of recurrence-free survival (RFS) met the pre-specified futility criteria. A higher rate of discontinuation of all adjuvant therapy by patients in the coformulation arm versus the KEYTRUDA-only arm, primarily due to immune-mediated adverse experiences, rendered it highly unlikely that the trial could achieve a statistically significant improvement in RFS.

Based on the recommendation of an independent Data Monitoring Committee (DMC), Merck is unblinding the study and recommends that patients receiving the vibostolimab and pembrolizumab coformulation be offered the option to be treated with KEYTRUDA monotherapy. Data analysis from this study is ongoing. Results will be shared with the scientific community and communicated to regulatory agencies.

“Through our clinical development program, we continue to ask the tough questions in an effort to fully explore the potential of novel coformulations and combinations that build on the foundation of KEYTRUDA, with a goal to improve upon current standards of care and help even more patients with cancer,” said Dr. Marjorie Green, senior vice president and head of oncology, global clinical development, Merck Research Laboratories. “We are grateful to the patients and investigators for their participation and will leverage insights from this trial as we rapidly advance our diverse pipeline of novel mechanisms, including further study of this coformulation in lung cancer.”

Vibostolimab is Merck’s investigational anti-TIGIT antibody that restores antitumor activity by blocking the TIGIT receptor from binding to its ligands (CD112 and CD155), thereby activating T lymphocytes that help destroy tumor cells.