Eisai has initiated a rolling submission to the US Food and Drug Administration (FDA) for approval of a more convenient version of its Alzheimer’s disease treatment Leqembi (lecanemab-irmb).
The biologics licence application (BLA) is for a subcutaneous autoinjector version of the drug that is currently infused.
A rolling submission allows a company to submit sections of an application as each one is completed, rather than waiting for the entire application to be finished. Eisai became eligible to apply via this pathway after winning fast track designation from the FDA, as per a 14 May press release.
Developed in partnership with Biogen, an intravenous (IV) form of Leqembi was approved in the US in July 2023. While the antibody-based therapy has made waves in the neurodegenerative disease space, its uptake has been hampered due to treatment logistics. Patients first require extensive imaging scans before taking the medication and often must travel to specialist sites for the infusion.
Eisai said in a Q3 FY 2023 earnings call that a total of 2,000 patients had been administered the treatment as of 26 January 2024. The company had set a target of 10,000 treated patients by the end of March.
Eisai and Biogen say the new autoinjector could be used to administer Leqembi at home and in medical facilities. If approved, the new formulation would be used as a 360mg dose for weekly maintenance dosing following a biweekly IV initiation phase. The two companies added that administering the under-the-skin injection requires less time compared to the original IV version.
Supporting the BLA is data from the Clarity AD (Study 301) open-label extension, along with modelling of observed data. Eisai and Biogen reported data at last year’s Clinical Trials on Alzheimer’s Disease annual meeting that demonstrated subcutaneous Leqembi worked just as well as the IV counterpart. Subcutaneous Leqembi cleared 14% more amyloid plaque in the brain in 71 patients compared to the original version. The drug works by targeting the buildup of amyloid plaques in the brain – a hallmark of Alzheimer’s disease and what is suggested as a cause of memory and cognition impairment.
The company was initially supposed to file this rolling BLA in March 2024, but the FDA requested more immunogenicity data, leading to a delay in filing.
However, Eisai and Biogen’s major competitor, Eli Lilly, is also facing delays with its Alzheimer’s therapy donanemab. It means that Eisai and Biogen currently enjoy market dominance in the Alzheimer’s disease treatment space. Biogen recently redirected all resources to Leqembi after cutting ties with its other Alzheimer’s asset Aduhelm (aducanumab-avwa).
Leqembi, which is also approved in Japan and China, is predicted to bring in global sales of $372m in 2024 according to GlobalData’s Pharma Intelligence Centre. The forecast for the drug is impressive, estimated to reel in $7.3bn by 2030.
GlobalData is the parent company of Pharmaceutical Technology.
Pricing could yet remain a hurdle for the drug’s long-term prospects. A year’s supply of the drug comes with a price tag of $26,600, and while Medicare said last year it would cover 80% of the drug’s $26,500 yearly price tag for eligible patients, a study has suggested this could cost the agency up to $5bn a year, demonstrating the possible healthcare burden.
