Merck-Eisai Combo Wins FDA Approval for Advanced Kidney Cancer

The US Food and Drug Administration (FDA) has approved Merck's WELIREG (belzutifan) in combination with Eisai's LENVIMA (lenvatinib) for adults with advanced renal cell carcinoma (RCC) who have progressed after treatment with a PD-1 or PD-L1 inhibitor.

The approval marks a new treatment option for patients with advanced kidney cancer following immunotherapy, according to Merck and Eisai. WELIREG is an oral hypoxia-inducible factor-2 alpha (HIF-2α) inhibitor, while LENVIMA is an oral multiple receptor tyrosine kinase inhibitor (TKI).

The FDA decision is based on results from the Phase 3 LITESPARK-011 trial, which showed that the combination of WELIREG and LENVIMA significantly improved progression-free survival (PFS) compared to cabozantinib. The combination reduced the risk of disease progression or death by 26%, with a hazard ratio of 0.74.

The median PFS was 14.6 months with WELIREG plus LENVIMA, compared to 10.6 months with cabozantinib. The combination also produced a significantly higher objective response rate (ORR), at 53% versus 40% for cabozantinib.

The companies said additional results, including duration-of-response data, will be presented at the European Society for Medical Oncology (ESMO) Congress 2026 in Madrid, Spain. Dr. Robert Motzer, Principal Investigator and Genitourinary Medical Oncologist, Memorial Sloan Kettering Cancer Center, stated that this approval represents an important development for patients and their physicians.