The U.S. Food and Drug Administration (FDA) on Wednesday approved Merck & Co. Inc.’s (NYSE:MRK) Welireg (belzutifan) for adult and pediatric patients 12 years and older with locally advanced, unresectable, or metastatic pheochromocytoma or paraganglioma (PPGL).

This represents the first FDA approval of an oral therapy for PPGL, rare neuroendocrine tumors that can spread to other parts of the body.

Welireg received approval from the FDA and European Medicines Agency for adult patients with advanced renal cell carcinoma (RCC).

Also Read: Merck’s Q1 Earnings Beat Wall Street, Adjusts 2025 Profit Outlook As Tariffs May Result In Incremental Cost Of $200 Million

Efficacy was evaluated in LITESPARK-015, an open-label, multi-cohort trial.

The major efficacy outcome measure was objective response rate (ORR). Additional efficacy outcome measures were duration of response (DOR) and the number of patients who had a reduction in at least one antihypertensive medication by at least 50%, maintained for at least six months.

ORR was 26%. Median DOR was 20.4 months. Of the 60 patients on baseline antihypertensive medications, 19 (32%) had a reduction in at least one antihypertensive medication by at least 50% for at least six months.

The recommended belzutifan dose for adults is 120 mg administered orally once daily.

The recommended dose for pediatric patients 12 years and older is based on body weight. For pediatric patients weighing ≥ 40 kg, the dose is 120 mg orally once daily.

For pediatric patients weighing < 40 kg, the dose is 80 mg orally once daily.

In the first quarter of 2025, Welireg generated sales of $137 million, 62% year over year.

Price Action: MRK stock is down 3.45% at $73.98 at the last check on Wednesday.

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This article FDA Approves Merck's Kidney Cancer Drug For Rare Type Of Neuroendocrine Tumors originally appeared on Benzinga.com

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