Welireg (belzutifan)
Q2 2026 sales $271M, up 67%; approved with Keytruda for adjuvant kidney cancer in 2026.
The numbers
What it is
Belzutifan, an oral HIF-2 alpha inhibitor for advanced renal cell carcinoma and other tumors. The 2026 Keytruda combination approval for adjuvant clear cell renal cell carcinoma widens its use.
Why it matters to the stock. Welireg shows Merck can grow a newer oncology brand alongside Keytruda, and the adjuvant label extends its time in patients.
News
FDA approves Welireg with Keytruda or Keytruda Qlex for adjuvant clear cell kidney cancer
The FDA approved Welireg (belzutifan) in combination with Keytruda or Keytruda Qlex for adjuvant treatment of adults with clear cell renal cell carcinoma at intermediate-high or high risk of recurrence after nephrectomy.
Welireg plus Keytruda cuts recurrence or death risk 28% in kidney cancer trial LITESPARK-022
Merck reported that adding Welireg to Keytruda reduced the risk of disease recurrence, metastasis or death by 28% versus Keytruda plus placebo in patients with earlier-stage clear cell kidney cancer at intermediate-high or high risk of recurrence.