![FDA approved belzutifan (Welireg) over a computer rendering 0f a tumor on a kidney.](http:http://assets.medpagetoday.net/media/images/107xxx/107885.jpg?width=0.8)
The for previously treated advanced renal cell carcinoma (RCC), the agency announced on Thursday.
Belzutifan is indicated for RCC patients with disease progression after a PD-1/L1 checkpoint inhibitor and a VEGF inhibitor, standard first-line options for this disease. Belzutifan, a hypoxia-inducible factor (HIF)-2α inhibitor, was previously approved only for von Hippel-Lindau-associated tumors.
Efficacy and safety data from LITESPARK-005 supported the new indication. The open-label trial randomized 746 patients who had progressed following a checkpoint inhibitor and a VEGF tyrosine kinase inhibitor (TKI) to once-daily treatment with either belzutifan or everolimus (Afinitor).
"Despite recent progress in the treatment of advanced RCC, there is yet to be an option specifically approved for patients whose disease progresses following a PD-1 or PD-L1 inhibitor and a TKI therapy," said investigator Toni Choueiri, MD, of the Dana-Farber Cancer Institute in Boston, in a from drugmaker Merck. "This approval of belzutifan introduces a meaningful new treatment option for certain patients, as belzutifan reduced the risk of disease progression or death compared to everolimus."
In the trial, belzutifan reduced the risk for progression or death by 25% versus everolimus (HR 0.75, 95% CI 0.63-0.90), though median progression-free survival values were an identical 5.6 months in both arms. Belzutifan also induced a higher objective response rate (22% vs 4%), including complete responses in 3% versus none in the everolimus-treated arm.
While overall survival results "were immature at the current analysis, with 59% of deaths reported, no trend towards a detriment was observed," according to the FDA. Furthermore, "a descriptive analysis of patient-reported symptom and functional outcomes was supportive of improved tolerability for belzutifan compared to everolimus."
In total, 6% of patients permanently discontinued the HIF-2α inhibitor due to toxicity.
Common adverse events (AEs) in patients treated with belzutifan included fatigue; musculoskeletal pain; decreases in hemoglobin, sodium, and lymphocytes; and increases in creatinine, potassium, and liver enzymes.
Serious AEs occurred in 38% of patients who received belzutifan, including hypoxia (7%), anemia (5%), pneumonia (3.5%), hemorrhage (3%), and pleural effusion (2.2%). Fatal adverse reactions occurred in 3.2% of patients who received belzutifan, including sepsis and hemorrhage (0.5% each).
The contains a boxed warning that exposure to belzutifan during pregnancy can cause embryo-fetal harm, and that the drug can render some hormonal contraceptives ineffective. Other warnings include risks for hypoxia and anemia. Belzutifan is contraindicated for patients on UGT2B17 or CYP2C19 inhibitors.