Merck's Welireg Expands Indication for Advanced Kidney Cancer

Merck's Welireg label has been expanded by the FDA for an additional indication in advanced renal cell carcinoma (RCC), the most common type of adult kidney cancer.

The approval is for the drug to be used in combination with Eisai's Lenvima, and it comes after data from a phase III trial showed that the regimen reduced the risk of disease progression or death by 26%.

The FDA approval adds to Welireg's existing indications in RCC, including as a monotherapy for certain patients following treatment with both a PD-1/PD-L1 inhibitor and a VEGF-TKI.

Merck reported $470 million in sales from Welireg in the first half of 2026, up 57% year-over-year, driven by higher demand in the US and continued launch uptake in international markets.