Merck’s Welireg meets Phase 3 primary endpoint in renal cell carcinoma

Merck announced topline results from LITESPARK-005, the first positive Phase 3 trial investigating Welireg, Merck’s oral hypoxia-inducible factor-2 alpha inhibitor. LITESPARK-005 is evaluating Welireg for the treatment of adult patients with advanced renal cell carcinoma – RCC – that has progressed following PD-1/L1 checkpoint inhibitor and vascular endothelial growth factor-tyrosine kinase inhibitor therapies. In the trial, Welireg showed a statistically significant and clinically meaningful improvement in progression-free survival compared to everolimus. A statistically significant improvement in the trial’s key secondary endpoint of objective response rate was also demonstrated. A trend toward improvement in overall survival, a dual primary endpoint, was observed; however, this result did not reach statistical significance. OS will be tested at a subsequent analysis. The safety profile of Welireg in this trial was consistent with that observed in previously reported studies. Results will be presented at an upcoming medical meeting and shared with regulatory authorities. Welireg was the first HIF-2alpha inhibitor therapy approved in the U.S. and is currently approved in the U.S., Great Britain, Canada and several other countries for the treatment of adult patients with von Hippel-Lindau disease who require therapy for associated RCC, central nervous system hemangioblastomas, or pancreatic neuroendocrine tumors, not requiring immediate surgery.