Eisai and Biogen said Tuesday that they started an application for an under-the-skin maintenance dosing version of their Alzheimer’s treatment Leqembi.
The subcutaneous submission was expected earlier this spring, but Eisai said April 1 that the FDA requested more immunogenicity data. At the time, analysts called the delay “a technicality but still disappointing.” The FDA has now granted the medication a fast track designation.
An FDA approval for the auto-injectable subcutaneous version could open a new chapter for Leqembi by allowing patients to administer it at home or in medical facilities. The companies have gradually rolled out Leqembi since its accelerated approval in January 2023.
The accelerated approval of the IV formulation has since been converted to a traditional approval. But uptake of the drug has been slow due to a range of reasons, including restricted insurance coverage by public and private payers, getting hospitals adequately staffed and equipped, and making sure that patients get the scans they need to determine they have the memory-robbing disease.
The IV formulation has also been approved in Japan and China, and applications have been sent to regulators in Canada, Brazil, Australia and various regions of Europe and Asia.
If approved, the weekly subcutaneous version would be given after patients complete their biweekly IV initiation phase, Eisai said. The drugmaker believes the new formulation would keep clearing the toxic protofibrils that “can continue to cause neuronal injury even after the amyloid-beta plaque has been cleared from the brain.” The drug comes with warnings for potential amyloid-related imaging abnormalities, or ARIA, which could signal brain bleeding and swelling.