The U.S. Food and Drug Administration has approved a once-weekly autoinjector version of Eisai's Alzheimer's drug Leqembi (lecanemab), introducing the first at-home dosing option for amyloid-based Alzheimer's therapy. The new injection, branded as Leqembi IQLIK, represents a significant advancement in treatment accessibility for patients managing early-stage Alzheimer's disease.
Treatment Administration and Availability
The 360mg autoinjector will be available to early Alzheimer's patients who are transitioning to maintenance dosing after completing 18 months of intravenous treatment administered every two weeks. Leqembi IQLIK is scheduled to launch in the US in October 2025, offering patients the convenience of self-administration at home.
The FDA approved the autoinjector as an alternative option for maintenance dosing of the beta-amyloid blocker. Currently, patients on maintenance therapy receive once-monthly intravenous infusions at a dose of 10mg/kg, a regimen that was approved by the FDA in February 2025.
Clinical Efficiency and Patient Benefits
The autoinjector dramatically reduces treatment time, requiring just 15 seconds for injection compared to the one hour typically needed for intravenous infusions. This efficiency improvement addresses key logistical challenges that have hampered Leqembi's uptake, particularly infusion logistics and capacity constraints.
According to Eisai and commercial partner Biogen, the autoinjector's approval allows patients to receive therapy at home while on maintenance doses, eliminating the need for visits to infusion centers. The pen's availability for a subset of patients also increases infusion capacity, enabling new patients to begin treatment more readily.
Regulatory Development and Clinical Evidence
The FDA's approval was based on results from the Phase III CLARITY AD study, which demonstrated no efficacy difference between patients switching to the autoinjector pen after 18 months of initial dosing. The regulatory pathway faced some delays, as Eisai was initially scheduled to file the biologics license application in March 2024, but the FDA requested additional immunogenicity data. The company eventually initiated the rolling submission in May 2024.
Market Position and Competitive Landscape
Leqembi represents the spearhead in a new generation of Alzheimer's drugs designed to slow disease progression. While Eisai and Biogen initially enjoyed market dominance following Leqembi's approval in 2023, competition emerged when Eli Lilly received FDA approval for Kisunla (donanemab) in 2024.
The two drugs target different aspects of beta-amyloid pathology. Leqembi targets small chains of linked-up beta-amyloid proteins called protofibrils, preventing amyloid buildup, while Kisunla specifically targets beta-amyloid plaques.
Commercial Challenges and Outlook
Both drug manufacturers have encountered uptake challenges due to high treatment costs. Reimbursement regulators across many countries have declined coverage, citing concerns that administration costs do not justify the clinical benefits. Eisai has acknowledged particularly slow uptake in the US, attributed to infusion logistics and diagnosis constraints.
Despite these challenges, Eisai projects Leqembi will generate ¥250 billion to ¥280 billion ($1.7 billion to $1.9 billion) in sales during its 2027 fiscal year. Independent analysis by GlobalData's Pharma Intelligence Center forecasts sales of $1.5 billion in 2027 and $2.2 billion in 2028.
