The purpose of this study is to evaluate the efficacy and safety of belzutifan monotherapy and belzutifan plus palbociclib combination therapy in participants with advanced clear-cell renal cell carcinoma (ccRCC) who experienced disease progression on or after receiving prior therapy. The study will establish the safety of belzutifan plus palbociclib and determine a recommended dosage of palbociclib for the combination therapy by ascending dose escalation.
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.