FDA approval expands Welireg to patients with renal cell carcinoma

Welireg was originally approved by the FDA in 2021 for a rare genetic condition. The latest approval allows the drug to be used in patients with advanced RCC that have previously received checkpoint inhibitors targeting programmed death receptor-1 (PD-1) or programmed death-ligand 1 (PD-L1) and blockers of vascular endothelial growth factor tyrosine kinase inhibitor (VEGF-TKI).

RCC is the most common form of kidney cancer and advanced forms are historically hard to treat​ with traditional chemotherapy. The arrival of checkpoint inhibitors and VEGF-TKI blockers is providing ever more options for patients with RCC.

However, more options are needed for patients whose cancer progresses after receiving these treatments, said a public release from MSD.

The approval decision was based on results from phase 3 trial named LITESPARK-005, where belzutifan boosted progression-free survival compared to the renal cell cancer therapy everolimus in patients whose cancer had progressed following treatment with a PD-1 or PD-L1 checkpoint inhibitor and a VEGF receptor targeted therapy.

“This approval of Welireg marks the first new therapeutic class available for eligible patients with advanced RCC in nearly a decade,” stated Marjorie Green, senior vice president and head of late-stage oncology, global clinical development, Merck Research Laboratories.

Welireg is an oral hypoxia-inducible factor-2 alpha (HIF-2α) inhibitor. MSD first got hold of the compound when it acquired the company Peloton Therapeutics in 2019 for up $2 billion.

The drug was first approved for the treatment of patients with von Hippel-Lindau (VHL) disease who require therapy for certain solid tumors, not requiring immediate surgery. MSD is also developing the drug for the treatment of more types of tumor including biliary tract, colorectal and endometrial cancer.