FDA clears two Welireg supplements for Merck's belzutifan, both approved September 24, 2026

The FDA approved two supplemental submissions for Welireg (belzutifan), sponsored by Merck Sharp Dohme, with a submission status date of 2026-09-24.

One supplement, numbered 17, was classified as a labeling submission. It carried standard review priority and was approved, with an updated label and medication guide dated September 28, 2026.¹

The second, numbered 13, was classified as an efficacy submission. It also carried standard review priority and was approved, with documentation including an updated label dated September 28, 2026 and an approval letter of the same date.²

Both supplements were filed under application number NDA215383. The labeling supplement, numbered 17, was marked "AP" for approved status.¹ The efficacy supplement, numbered 13, was also marked "AP" for approved status.²

Welireg is formulated as an oral tablet. The product contains belzutifan as its active ingredient at a strength of 40MG.¹ The same 40MG oral tablet formulation applies to the efficacy supplement filing.²

The FDA drug application records do not specify what clinical or labeling changes prompted either supplement beyond their classification as labeling and efficacy submissions respectively.