Merck’s Welireg for PPGL approved by FDA

Merck (MRK) announced the FDA has approved Welireg – belzutifan -, Merck’s oral hypoxia-inducible factor-2 alpha inhibitor, for the treatment of adult and pediatric patients 12 years and older with locally advanced, unresectable, or metastatic pheochromocytoma or paraganglioma – PPGL -. Pheochromocytoma and paraganglioma are rare tumors that come from the same tissue, but pheochromocytoma form in the adrenal gland and paraganglioma form outside the adrenal gland. These tumors can be caused by certain genetic syndromes or mutations. The approval is based on data from the single-arm LITESPARK-015 clinical trial, where the primary endpoint was objective response rate. Additional efficacy outcome measures included duration of response and time to response.