Merck’s Welireg (belzutifan) plus Keytruda (pembrolizumab) gained FDA approval for adjuvant use in clear cell renal cell carcinoma, marking the first approval for a PD-1 and HIF-2 alpha inhibitor combination in the post-surgery setting. The agency cleared the regimen for adults at intermediate-high or high risk of recurrence following kidney-removal surgery. The approval builds on Litespark-022, Merck’s pivotal adjuvant study in which Welireg and Keytruda reduced the risk of disease recurrence, metastasis, or death by 28% versus Keytruda plus placebo. Merck cited a 74% versus 81% estimated disease-free survival rate in the respective arms, while overall survival data remain immature. For the biotech market, the decision extends Merck’s immunotherapy franchise into an earlier-stage RCC opportunity and intensifies competition in adjuvant oncology.