Merck & Co., Inc. — Welireg FDA Review (NDA/BLA 215383, 2026)
Merck & Co., Inc. · 2026 · FDA Review (Drugs@FDA) · company profile →
Report summary
Merck & Co., Inc. received FDA approval for WELIREG (belzutifan) on December 14, 2023, for VHL-associated tumors and advanced renal cell carcinoma (RCC). The advanced RCC approval, based on the LITESPARK-005 trial, compared belzutifan to everolimus in patients previously treated with PD-1/PD-L1 inhibitors and VEGF-TKIs. Belzutifan demonstrated statistically significant improvements in progression-free survival (PFS) and objective response rate (ORR) compared to everolimus, with a favorable safety profile. While overall survival (OS) data was immature, it trended positively. The FDA agreed with the study design, including everolimus as a comparator, and found the clinical data reliable. A postmarketing commitment requires final OS analysis from LITESPARK-005. The approval package details drug information, clinical pharmacology, and adverse reactions, with no REMS required.
Key findings — cited to the page
| Fatigue (All Grades) | 64 % | LITESPARK-004 · p.14 |
| Nausea (All Grades) | 31 % | LITESPARK-004 · p.14 |
| Decreased hemoglobin (Grade 3 events) | 7 % | WELIREG (belzutifan) · p.12 |
| Hypoxia (Grade 3 events) | 10 % | WELIREG (belzutifan) · p.13 |
| Headache (All Grades) | 39 % | LITESPARK-004 · p.14 |
| Dizziness (All Grades) | 38 % | LITESPARK-004 · p.14 |
| Weight increased (Grade 3-4) | 1.6 % | LITESPARK-004 · p.14 |
| Decreased hemoglobin (all grades) | 93 % | WELIREG (belzutifan) · p.12 |
| Decreased hemoglobin (all grades) | 88 % | WELIREG (belzutifan) · p.12 |
| Decreased hemoglobin (Grade 3 events) | 29 % | WELIREG (belzutifan) · p.12 |
| Fatigue (Grade 3-4) | 5 % | LITESPARK-004 · p.14 |
| Constipation (All Grades) | 13 % | LITESPARK-004 · p.14 |
Source: Merck & Co., Inc. ↗ · License: US Government public domain. Summary and findings are extracted from the published document; every figure cites its page. Informational only — not investment advice. Explore the Oncology library →