Merck's First-in-Class HIF-2α Inhibitor Welireg Demonstrates Positive Phase III Results in Advanced Renal Cell Carcinoma

On October 28, MSD (MRK.US) announced two pieces of news: 1) The Phase III LITESPARK-011 trial evaluating the dual oral therapy Welireg (belzutifan) in combination with lenvatinib for the treatment of advanced renal cell carcinoma patients whose disease progressed after prior anti-PD-1/L1 therapy met one of its primary endpoints of progression-free survival (PFS). Belzutifan is an orally administered hypoxia-inducible factor-2α (HIF-2α) inhibitor pioneered by MSD.

In the pre-specified interim analysis, the combination of beguotifan and lenvatinib demonstrated a statistically significant and clinically meaningful improvement in PFS compared to cabozantinib. This combination therapy also showed a statistically significant improvement in the key secondary endpoint of objective response rate (ORR) compared to cabozantinib.

Renal Cell Carcinoma (RCC) is the most common type of kidney cancer, with approximately nine out of ten kidney cancer diagnoses being RCC. In 2022, there were about 435,000 new cases of kidney cancer diagnosed globally, and around 156,000 people died from the disease. The incidence of RCC in men is roughly twice that in women. Most cases of renal cell carcinoma are discovered incidentally during imaging tests for other abdominal conditions. Approximately 30% of kidney cancer patients are diagnosed at an advanced stage.