FDA approval makes Alzheimer’s treatment easier with subcutaneous lecanemab
Weekly autoinjector option may reduce burden of IV infusions for early Alzheimer’s patients
The FDA has approved a weekly subcutaneous (under the skin) formulation of lecanemab (Leqembi Iqlik, Eisai/Biogen) for maintenance treatment in patients with early Alzheimer’s disease.
Data show that switching from IV infusions to the autoinjector maintains clinical benefit while reducing infusion-related side effects.
Study Details:
Lecanemab, marketed as Leqembi, is an anti-amyloid antibody already FDA-approved for treating early Alzheimer’s disease in patients with mild cognitive impairment or mild dementia. Until now, treatment required biweekly intravenous infusions at 10 mg/kg, followed by monthly infusions after the first 18 months.
The new subcutaneous formulation was evaluated in the open-label extension of the phase 3 Clarity AD trial, which demonstrated sustained disease-modifying benefit over 4 years with continuous treatment.
Methodology:
Patients who had completed 18 months of IV lecanemab were given the option to continue IV dosing every 4 weeks or transition to a weekly 360 mg subcutaneous autoinjector. Researchers tracked clinical outcomes, biomarker responses, and safety over time, comparing both groups.
Key Findings:
Subcutaneous lecanemab maintained the same clinical and biomarker benefits as IV maintenance dosing.
Systemic infusion reactions were significantly less common (<1% with subcutaneous vs 26% with IV).
Local injection-site reactions occurred in ~11% of patients, typically mild and non-disruptive.
Rates of amyloid-related imaging abnormalities (ARIA), a known risk with lecanemab, remained similar across both groups, with most occurring during initial IV treatment.
Implications for Practice:
For patients and caregivers, the availability of a weekly autoinjector may substantially reduce the logistical burden of Alzheimer’s treatment, shifting care closer to a model similar to diabetes or GLP-1 medications.
For clinicians, it represents a practical option that maintains efficacy while improving tolerability and convenience.
Experts highlight this approval as a step toward broader at-home treatment delivery and potential combination therapies tailored to individual biomarker profiles, signaling the next stage of precision medicine in Alzheimer’s disease.