MRK's sNDA for Welireg in Rare Tumors Gets FDA's Priority Tag

Core Viewpoint - Merck's supplemental new drug application for Welireg has been accepted by the FDA, seeking approval for treating advanced pheochromocytoma and paraganglioma, marking a significant step in addressing a gap in treatment options for these rare tumors [1][5]. Regulatory Updates - The FDA has granted a priority review for the sNDA, with a decision expected on May 26, 2025 [2]. - The sNDA is based on data from the phase II LITESPARK-015 study, focusing on objective response rate and duration of response [2]. - The European Medicines Agency's CHMP has recommended conditional approval for Welireg for two indications, with a final decision expected in the first quarter of 2025 [8][9]. Market Performance - Merck's stock has decreased by 19.2% over the past year, contrasting with a 2.2% decline in the industry [4]. - Welireg generated sales of $349 million in the first nine months of 2024, driven by increased uptake for advanced RCC [10]. Product Development - Welireg is currently approved for advanced renal cell carcinoma and certain tumors associated with von Hippel-Lindau disease, and if approved for advanced PPGL, it will be the only treatment available for this condition in the U.S. [5]. - Merck is exploring Welireg as a monotherapy and in combination with other therapies for various rare cancer indications [9].