TOKYO and CAMBRIDGE, MA, August 30, 2025 - (JCN Newswire) - Eisai Co., Ltd. (Headquarters: Tokyo, CEO: Haruo Naito, “Eisai”) and Biogen Inc. (Nasdaq: BIIB, Headquarters: Cambridge, Massachusetts, CEO: Christopher A. Viehbacher, “Biogen”) announced today that the U.S. Food and Drug Administration (FDA) has approved the Biologics License Application (BLA) for once weekly lecanemab-irmb subcutaneous injection (U.S. brand name: LEQEMBI® IQLIKTM, pronounced “I Click”) for maintenance dosing. LEQEMBI IQLIK is a subcutaneous autoinjector (SC-AI) developed by Eisai, containing 360 mg/1.8 mL (200 mg/mL) that can be administered in approximately 15 seconds. LEQEMBI IQLIK autoinjector is indicated for maintenance dosing to treat Alzheimer's disease (AD) in patients with mild cognitive impairment (MCI) or mild dementia stage of disease(collectively referred to as early AD) in the U.S. After 18 months of LEQEMBI (lecanemab-irmb) intravenous(IV) treatment at 10 mg/kg every two weeks, patients may either continue IV infusions at 10 mg/kg once every four weeks or start the new weekly 360 mg subcutaneous injection using the LEQEMBI IQLIK autoinjector.

Clinical Trials Supporting Subcutaneous Maintenance Dosing Approval

• The BLA is based on LEQEMBI subcutaneous (SC) sub-studies of the Phase 3 Clarity AD open-label extension (OLE) trial in individuals with early AD, which evaluated a range of subcutaneous doses. Data shows that transitioning to the weekly LEQEMBI IQLIK autoinjector after 18 months of the initiation dose (10 mg/kg IV every two weeks) maintains clinical and biomarker benefits comparable to continued IV dosing.
• The safety of LEQEMBI IQLIK autoinjector was studied in over 600 patients at a range of doses as part of the Clarity AD OLE.
• 49 patients received a weekly 360 mg subcutaneous maintenance dose after at least 18 months of 10mg/kg IV every two weeks. Importantly, none of these patients experienced any local or systemic injection-related adverse events (AEs).
• Across all subcutaneous doses, the safety profile was similar to that of the IV maintenance treatment with one key difference: systemic reactions were much less common with subcutaneous dosing—less than 1% compared to approximately 26% with IV infusions. Approximately 11% of patients experienced mild-to-moderate local reactions (such as redness, swelling or itching at the injection site), which did not interfere with continued administration, and less than 1% had mild systemic symptoms such as headache, fever or fatigue.
• ARIA rates in patients who received a weekly 360 mg subcutaneous maintenance dose were similar to ARIA rates reported in patients who continued with the IV dose after 18 months and are similar to the background rates of ARIA in patients without treatment. ARIA is usually asymptomatic, although serious and life-threatening events can occur. ARIA can be fatal. Most ARIA with LEQEMBI occurs within the first 6 months of IV initiation treatment. 

Importance of Ongoing Treatment

AD is a progressive, relentless disease with amyloid beta (Aβ) and tau as hallmarks, caused by a continuous underlying neurotoxic process that begins before amyloid plaque removal and continues afterward(1,2,3). Only LEQEMBI fights AD in two ways – targeting both amyloid plaque and protofibrils*, which can impact tau downstream. Due to the reaccumulation of AD biomarkers and return to placebo rate of decline after therapy is stopped(4,5), maintenance treatment with once-weekly SC injection or once every four weeks of IV therapy offers patients options to continue slowing the disease progression and prolong the benefit of therapy, with the goal of helping patients maintain who they are for longer.

• In the Clarity AD core study, the mean change from baseline between the lecanemab IV once every 2 weeks treated group and the placebo group after 18 months was -0.45 (P=0.00005) on the primary endpoint of CDR-SB global cognitive and functional scale.
• To provide context, a change from 0.5 to 1 on the Clinical Dementia Rating (CDR) score domains of Memory, Community Affairs and Home/Hobbies reflects a shift from mild impairment to loss of independence. This can affect a person's ability to be left alone safely, recall recent events, participate in daily activities, manage household tasks, and engage in hobbies and intellectual interests(6,7).** 
• At 48 months of treatment through the Clarity AD core study and its OLE, data showed lecanemab demonstrated a reduction in cognitive decline measured by CDR-SB of -1.75 points compared to the expected decline observed in the Alzheimer's Disease Neuroimaging Initiative (ADNI)*2 cohort.
• Similarly, when benchmarked against the expected decline in the BioFINDER*3 cohort, lecanemab showed a reduction of -2.17 points measured by CDR-SB at the four-year mark.

Importance of SC Maintenance Option

To confirm the safe and effective use of LEQEMBI IQLIK in the expected use environments, additional studies were conducted, including a human factors (HF) study*4 and a tolerability assessment of the device. From the perspective of patients and care partners, benefits included the ability to use the device at home, shortening treatment time and to continue treatment without having to worry about visiting an infusion center. Healthcare providers reported that the device has the potential to provide a new option for patients who are responding well to LEQEMBI and should continue treatment. The SC formulation also has the potential to reduce healthcare resources associated with IV maintenance dosing, such as preparation for infusion and nurse monitoring, while increasing infusion capacity for new eligible patients to begin initiation treatment and streamlining the overall AD treatment pathway.

Patient Support Programs

Eisai is committed to ensuring that appropriate patients have access to LEQEMBI. In the U.S. Eisai offersseveral support programs to help patients and care partners. Dedicated Patient Navigators will work directlywith patients and families to navigate treatment and coverage for eligible and appropriate patients and to helpwith what to expect regarding insurance coverage, co-pay and patient access programs. Injection support willalso be available for LEQEMBI IQLIK patients. To learn more visit LEQEMBI.com, call 1-833-4-LEQEMBI (1-833-453-7362), Monday-Friday, 8 a.m. to 8 p.m. Eastern Time.

In addition, to support access to LEQEMBI for certain patients who need help paying for their medicines, Eisai’s Patient Assistance Program (PAP) will provide LEQEMBI and LEQEMBI IQLIK at no cost, for eligible uninsured and underinsured patients, including Medicare beneficiaries, who meet financial need and other program criteria.

LEQEMBI IQLIK will be launched on October 6, 2025 in the U.S. Click here to learn about how LEQEMBIIQLIK offers patient-centric early Alzheimer's care and our U.S. Pricing Approach.

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. 

For more details, please visit: https://www.eisai.com/news/2025/pdf/enews202559pdf.pdf

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