FDA Accepts BLA for Leqembi SC for Alzheimer's

Leqembi is indicated for the treatment of Alzheimer’s disease (AD) in patients with Mild Cognitive Impairment (MCI) or mild dementia stage of disease (collectively referred to as early AD). A Prescription Drug User Fee Act (PDUFA) action date is set for August 31, 2025.

The BLA is based on data from the Clarity AD (Study 301) open-label extension (OLE) and modeling of observed data. If Leqembi subcutaneous maintenance dosing is approved by the FDA, Leqembi will be the only treatment for AD that can be administered subcutaneously at home using an autoinjector (AI). The injection process is expected to take, on average, 15 seconds. As part of the SC-AI 360 mg weekly maintenance regimen, patients who have completed the biweekly intravenous (IV) initiation phase, exact period under discussion with the FDA, would receive weekly doses that are expected to maintain the clinical and biomarker benefits.

AD is a progressive, relentless disease caused by a continuous underlying neurotoxic process that begins before and continues after plaque deposition. .Only Leqembi  works to fight AD in two ways by continuously clearing protofibrils and rapidly clearing plaque. With continuous administration, Leqembi clears highly toxic protofibrils which can continue to cause neuronal injury even after amyloid-beta (Aβ) plaque has been cleared from the brain. Long-term three-year Leqembi data presented at the Alzheimer’s Association International Conference (AAIC) 2024 suggest that early and continuing treatment may prolong the benefit of therapy even after plaque is cleared from the brain.

The SC-AI is expected to be simple and easy for patients and their care partners to use, and may reduce the need for hospital or infusion site visits and nursing care for IV administration, which will make it easier to continue maintenance administration and may contribute to further simplifying the treatment pathway for AD.

Leqembi is approved in the U.S., Japan, China, South Korea, Hong Kong, Israel, UAE, Great Britain, Mexico, and Macau. In November 2024, the treatment received a positive opinion from the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency (EMA) recommending approval. Eisai has submitted applications for approval of lecanemab in 17 countries and regions. The accepted Eisai’s Supplemental Biologics License Application (sBLA) for monthly Leqermbi maintenance dosing in June 2024 and set a PDUFA action date for January 25, 2025.

Eisai serves as the lead for lecanemab’s development and regulatory submissions globally with Eisai and Biogen co-commercializing and co-promoting the product and Eisai having final decision-making authority.

* Protofibrils are believed to contribute to the brain injury that occurs with AD and are considered to be the most toxic form of Abeta, having a primary role in the cognitive decline associated with this progressive, debilitating condition.  Protofibrils cause injury to neurons in the brain, which in turn, can negatively impact cognitive function via multiple mechanisms, not only increasing the development of insoluble Abeta plaques but also increasing direct damage to brain cell membranes and the connections that transmit signals between nerve cells or nerve cells and other cells. It is believed the reduction of protofibrils may prevent the progression of AD by reducing damage to neurons in the brain and cognitive dysfunction.