EU gives Welireg a restrained thumbs up

With HIF2α inhibition in focus, courtesy of Gilead's decision not to take up rights to Arcus's casdatifan, Merck & Co's rival Welireg was notable on Tuesday for having added EU approvals to its earlier US green lights. However, it won't go unnoticed that the EMA is being rather tougher than the FDA, which in December 2023 was happy to give Welireg formal approval in renal cancer ahead of its PDUFA date, and in spite of the lack of an overall survival benefit in the supporting Litespark-005 study. Perhaps the most obvious difference in the regulators' stances is that the EMA has only seen it fit to give the drug a conditional approval, which must be renewed yearly pending data from Litespark-004, a first-line study, and another unnamed trial. Unlike the FDA, the EMA has also mandated the failure of two VEGF kinase inhibitors, not just one, in the renal cancer indication. It is of course positive that HIF2α inhibition remains an approvable pharmacology, and the shortcomings of Welireg highlight the need for better molecules; but for Arcus it's unfortunate that Gilead doesn't think casdatifan is such a molecule.

A tale of two agencies: Welireg's approvals

Note: VHL=Von Hippel-Lindau. Source: Merck & Co and prescribing information.