LEQEMBI: A Breakthrough in Alzheimer's Treatment

LEQEMBI is the only FDA-approved anti-amyloid therapy that potentially could offer the convenience of a subcutaneous injection with at-home administration option.

TOKYO and CAMBRIDGE, Mass., Jan. 13, 2025 /PRNewswire/ -- Eisai Co., Ltd. (Headquarters: Tokyo, CEO: Haruo Naito, "Eisai") and Biogen Inc. (Nasdaq: BIIB, Corporate headquarters: Cambridge, Massachusetts, CEO: Christopher A. Viehbacher, "Biogen") announced today that the U.S. Food and Drug Administration (FDA) has accepted Eisai's Biologics License Application (BLA) for lecanemab-irmb (U.S. brand name: LEQEMBI®) subcutaneous autoinjector (SC-AI) for weekly maintenance dosing. 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 US FDA accepted Eisai's Supplemental Biologics License Application (sBLA) for monthly LEQEMBI IV 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 Aβ, 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 Aβ 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 that the reduction of protofibrils may prevent the progression of AD by reducing damage to neurons in the brain and cognitive dysfunction.

INDICATION

LEQEMBI® [(lecanemab-irmb) 100 mg/mL injection for intravenous use] is indicated for the treatment of Alzheimer's disease (AD). Treatment with LEQEMBI should be initiated in patients with mild cognitive impairment (MCI) or mild dementia stage of disease, the population in which treatment was initiated in clinical trials.

IMPORTANT SAFETY INFORMATION

WARNING: AMYLOID-RELATED IMAGING ABNORMALITIES (ARIA)

CONTRAINDICATION

LEQEMBI is contraindicated in patients with serious hypersensitivity to lecanemab-irmb or to any of the excipients of LEQEMBI. Reactions have included angioedema and anaphylaxis.

WARNINGS AND PRECAUTIONS

AMYLOID-RELATED IMAGING ABNORMALITIES Medications in this class, including LEQEMBI, can cause ARIA-E, which can be observed on MRI as brain edema or sulcal effusions, and ARIA-H, which includes microhemorrhage and superficial siderosis. ARIA can occur spontaneously in patients with AD, particularly in patients with MRI findings suggestive of cerebral amyloid angiopathy (CAA).

Reported ARIA symptoms may include headache, confusion, visual changes, dizziness, nausea, and gait difficulty. Symptoms usually resolve over time.

Incidence of ARIA

Symptomatic ARIA occurred in 3% and serious ARIA symptoms in 0.7% with LEQEMBI. Clinical ARIA symptoms resolved in 79% of patients during the period of observation.

Risk Factors of ARIA and ICH

ApoE ε4 Carrier Status: Of the patients taking LEQEMBI, 16% were ApoE ε4 homozygotes. Symptomatic ARIA-E occurred in 9% of ApoE ε4 homozygotes vs 2% of heterozygotes.

ADVERSE REACTIONS

The most common adverse reactions reported in ≥5% with LEQEMBI and ≥2% higher than placebo were infusion-related reactions, headache, and nausea/vomiting.

Please see full Prescribing Information for LEQEMBI, including Boxed WARNING.

Notes to Editors

1. About lecanemab (LEQEMBI®)

Lecanemab is the result of a strategic research alliance between Eisai and BioArctic. It is a humanized immunoglobulin gamma 1 (IgG1) monoclonal antibody directed against aggregated soluble (protofibril) and insoluble forms of amyloid-beta (Aβ).

2. About the Collaboration between Eisai and Biogen for AD

Eisai and Biogen have been collaborating on the joint development and commercialization of AD treatments since 2014.

3. About the Collaboration between Eisai and BioArctic for AD

Since 2005, Eisai and BioArctic have had a long-term collaboration regarding the development and commercialization of AD treatments.

4. About Eisai Co., Ltd.

Eisai's Corporate Concept is "to give first thought to patients and people in the daily living domain, and to increase the benefits that health care provides."

5. About Biogen

Founded in 1978, Biogen is a leading biotechnology company that pioneers innovative science to deliver new medicines to transform patients' lives.

Biogen Safe Harbor

This news release contains forward-looking statements, including about the potential clinical effects of lecanemab.

References

SOURCE Eisai Inc.