Merck (MSD) will end the Keytruda and investigational anti-TIGIT antibody coformulation arm of a phase 3 melanoma trial following a high rate of patient discontinuation.
The KeyVibe-010 trial is evaluating a combo of vibostolimab, an anti-TIGIT antibody and Keytruda, Merck’s blockbuster anti-PD-1 therapy, compared to Keytruda alone, as adjuvant treatment for patients with resected high-risk melanoma (stage IIB-IV). However, at pre-planned analysis, data showed that it was unlikely that the combo arm would meet its primary endpoint of recurrence-free survival, primarily due to immune-mediated adverse experiences.
Merck is now unblinding the study and recommending that the patients in the combo arm be offered the option to be treated with Keytruda alone.
Vibostolimab 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. Merck has been studying the vibostolimab-Keytruda combo alone and along with other agents in over 3,000 patients.
Back in December, Merck reported that the combo plus chemo failed to reach statistical significance in a phase 2 metastatic non-small cell lung cancer trial, despite extending median progression-free survival by 2.4 months compared to chemo alone.
