(Reuters) - The U.S. Food and Drug Administration said on Wednesday it has approved the expanded use of Merck (NSE:PROR)’s cancer drug to treat two rare types of adrenal gland tumors.
The drug, Welireg, became the first FDA-approved oral treatment for pheochromocytoma and paraganglioma (PPGL), providing a convenient option for up to 2,000 patients diagnosed with these tumors in the United States each year.
The two tumor types affect the gland that release the adrenaline hormone, which triggers the body’s defense mechanism. Pheochromocytoma occurs in the center of the adrenal gland, whereas paraganglioma occurs in the nerve tissue in the adrenal glands and near certain blood vessels and nerves.
The tumors can be caused by certain genetic syndromes or mutations.
The regulator’s approval was based on a study in which Welireg showed an objective response rate of 20.6%. ORR is the percentage of people who have a partial response or complete response to the treatment within a certain period of time.
Welireg is approved in patients above the age of 12 whose cancer has spread to other parts of the body, or it cannot be removed surgically.
Surgery is typically used to treat PPGL. Other treatment options include Exelixis (NASDAQ:EXEL)’ drugs Cabometyx and Cometriq and the generic drug sunitinib, but they are used only to relieve symptoms.
The first drug approved for the disease was Lantheus (NASDAQ:LNTH)’ Azedra in 2018, but was discontinued in 2023 due to limited usage and costs associated with its manufacturing.
Merck’s Welireg is also approved for cancers associated with Von Hippel-Lindau Disease, and a type of kidney cancer called renal cell carcinoma.
Welireg brought in $509 million in sales for Merck last year.