Game-Changer in Alzheimer’s Care: Lecanemab SC-AI Gets FDA Approval

Key Update on Lecanemab:

On 29^th August 2025, US FDA Approved Lecanemab Subcutaneous Autoinjector (SC-AI), Marking First At-Home Treatment for Alzheimer Disease

Key takeaways

• Enhanced accessibility and convenience: The approval of the subcutaneous autoinjector (branded as Leqembi Iqlik) provides a weekly, at-home maintenance treatment option for early Alzheimer's disease (AD) patients. This significantly reduces the burden of regular, time-consuming visits to infusion centres for patients and their caregivers.
• Bioequivalent efficacy: Sub-studies of the Phase 3 Clarity AD trial's open-label extension showed that the subcutaneous autoinjector maintains clinical and biomarker benefits comparable to continued intravenous (IV) dosing. Patients can switch to the autoinjector after an initial 18-month IV treatment period.
• Improved tolerability and reduced systemic reactions: While the overall safety profile is similar to the IV formulation, the subcutaneous injection resulted in significantly fewer systemic injection-related adverse events, such as fever or chills. Localized injection-site reactions (e.g., redness, swelling) were mild and did not impede administration.
• New monitoring guidance for ARIA: The FDA has updated its recommendations for Lecanemab, now suggesting an MRI scan before the third infusion of the drug to catch early cases of Amyloid-Related Imaging Abnormalities (ARIA-E), a key safety risk. 

KOL opinions

• Maria C. Carrillo, PhD (Alzheimer's Association): Praises the approval as "continued progress" in AD treatment, noting the evolution of amyloid-targeting antibodies and the importance of improved drug delivery methods.
• Howard Fillit, MD (Alzheimer's Drug Discovery Foundation): Calls the shift to subcutaneous dosing a "crucial step" toward greater accessibility for patients. He also emphasizes that "subcutaneous delivery is more than an upgrade—it’s a gateway to the next generation of Alzheimer's care" through multi-modal combination therapies.

Key implications:

• Patient empowerment and adherence: The at-home administration model will empower patients and caregivers, potentially leading to higher treatment uptake and better long-term adherence, which is crucial for maximizing the clinical benefits of these therapies.
• Resource optimization: Healthcare systems will see reduced strain on infusion centers and nursing staff, freeing up resources for earlier-stage patients or those requiring initial IV treatment.
• Competitive pressure for donanemab: Eli Lilly's donanemab (Kisunla) will face increased market pressure from the more convenient administration of the lecanemab autoinjector, particularly for patients prioritizing ease of use over donanemab's less frequent monthly infusion schedule. This could accelerate the development of a home-administered version of donanemab as well. The market share of lecanemab is anticipated to be >60% in the monoclonal antibodies treatment for early Alzheimer’s treatment in 2026.
• Facilitating combination therapy: The easier administration of the lecanemab autoinjector opens the door for future combination therapies. As one KOL noted, this is a "gateway" to multi-modal regimens that target different disease mechanisms, such as both amyloid and tau pathology, from the patient's home.
• Continued focus on safety and monitoring: The updated MRI protocols for both lecanemab and donanemab highlight that despite treatment improvements, careful monitoring for ARIA remains a cornerstone of safety management for anti-amyloid treatments. This will continue to be a key consideration for clinicians and healthcare systems.
• Subcutaneous uptake is projected to be significant: Of the patients receiving treatment in the model, nearly half (49.4%, or 31,093 patients) were projected to opt for the new subcutaneous autoinjector (SC-AI) for maintenance dosing. This indicates a strong patient and caregiver preference for the convenience of at-home administration once the initial IV phase is complete.
• Reduced logistical and financial burden on patients and caregivers
  • Substantial per-patient savings: A four-year societal perspective model estimates that the SC-AI would yield an average per-patient saving of $72,891 to $80,925 compared to IV administration. This represents an annual savings of $18,223 to $20,231 per patient, depending on the willingness-to-pay threshold used for the quality-adjusted life-year (QALY) calculation.
  • Primary drivers of savings: These savings are broken down into three key areas:
    • Treatment costs: An estimated $40,638 reduction in costs per patient over four years. This is driven partly by eliminating drug wastage that occurs with weight-based IV dosing and the lower required maintenance dose in the SC regimen.
    • Administration time costs: A $8,151 decrease in costs associated with administration time, reflecting the shorter time required for home injection versus infusion center visits.
    • Quality of Life (QOL) related costs: The largest component of the savings is an estimated $24,102 to $32,136 reduction in QOL-related expenses. This quantifies the value of reducing the immense burden on caregivers and improving the overall quality of life for both patients and their families by eliminating the need for frequent, time-consuming infusion appointments.