The FDA has granted Priority Review to new applications for belzutifan (Welireg) combined with Pembrolizumab (Keytruda). A decision is expected by June 19, 2026. The application is based on results from the Phase 3 LITESPARK-022 study.
The trial included 1,841 patients with clear cell renal cell carcinoma (ccRCC) at high risk of recurrence after kidney surgery. Patients received pembrolizumab plus daily belzutifan for about one year, or pembrolizumab plus placebo. The combination reduced the risk of cancer returning or death by 28% compared with pembrolizumab alone. At 30 months, 75.8% of patients in the combination group were disease-free, compared with 68.6% in the pembrolizumab-only group. Overall survival data are still early and not yet statistically significant.
Side effects were more common with the combination treatment. Nearly all patients (96.6%) experienced treatment-related side effects, compared with 80.7% in the control group. About 10.2% of patients stopped treatment due to side effects, compared with 7.3% in the pembrolizumab-only group.