Real or imagined, the Leqembi barriers emerge

Even during a poor day’s trading in Japan, today’s 5% fall in Eisai stock seems notable. At least part of the reason lies in the unexpected boxed warning the FDA yesterday put on the US label of the group’s Alzheimer’s drug Leqembi, relating to risk of the brain swelling disorder Aria. This came as the regulator converted the drug’s accelerated approval into a full green light, which had been on the cards after last month’s unanimous adcom vote. The label had previously recommended regular MRIs to check for Aria. Another key aspect was how the FDA would deal with populations thought to be at particular risk, and in the event the full label has recommended genetic testing for ApoE4 status before starting a patient on Leqembi “to inform the risk of developing Aria”. On the plus side the Centers for Medicare & Medicaid Services said reimbursement would be broadened to coverage with evidence development with a registry, though the agency had already implied that it would do this in the event of full approval. SVB analysts reckon doctors had already been planning to treat patients accordingly, but with blockbuster sales at stake barriers to uptake are evidently a concern.