This study is a substudy being conducted under one pembrolizumab umbrella master study KEYMAKER-U04. The substudy will consist of 2 parts. Part 1 will evaluate the efficacy and safety of coformulated favezelimab/pembrolizumab plus EV and coformulated vibostolimab/pembrolizumab plus EV relative to pembrolizumab plus EV. There will be no comparison of coformulated favezelimab/pembrolizumab plus EV versus coformulated vibostolimab/pembrolizumab plus EV. If ORR and/or DRR are substantially better on coformulated favezelimab/pembrolizumab plus EV and/or coformulated vibostolimab/pembrolizumab plus EV compared with pembrolizumab plus EV, after evaluation of the totality of data, the sponsor might consider Part 2 (expansion) to further characterize the efficacy and safety of the treatment arms under study.
Phase 1 trials primarily test safety and dosing in a small number of participants (typically 20–100). Results do not yet speak to efficacy. FDA approval is typically many years away from this stage.
Phase 2 trials begin testing efficacy in a larger patient group (100–300). This is often where biotech binary events occur — positive Phase 2 data can significantly advance a company's pipeline narrative, while failures can be terminal for a program.
Enrollment is complete. The trial is in its follow-up or data collection phase — a readout may occur on or near the primary completion date.
Merck & Co (MRK) is the sponsoring company for this trial. BiotechSign currently grades this company F (35/100) based on composite catalyst signals across its full pipeline. This trial is one data point in that overall catalyst picture.