Eisai and Biogen have initiated a rolling submission to the U.S. Food and Drug Administration (FDA) for a subcutaneous (SC) formulation of lecanemab-irmb (Leqembi) for weekly maintenance dosing in patients with early Alzheimer's disease. This new formulation aims to simplify administration and improve patient convenience.
The rolling submission is supported by data from the Phase 3 Clarity AD study. Lecanemab is currently approved for intravenous (IV) administration every two weeks, indicated for treating Alzheimer's disease in patients with mild cognitive impairment or mild dementia.
Potential Benefits of Subcutaneous Lecanemab
The SC formulation, administered via an autoinjector, offers several potential advantages over the IV formulation:
- Simplified Administration: The autoinjector allows for easier administration at home or in medical facilities, reducing the time required for each dose.
- Reduced Hospital Visits: By enabling at-home administration, the SC formulation may decrease the need for frequent hospital visits and post-administration care.
- Improved Convenience: Weekly maintenance dosing with the SC formulation is designed to be more convenient for both patients and caregivers.
Eisai's initial target of 10,000 patients on Leqembi by the end of 2023 was hampered by the challenges associated with IV administration, with only 2,000 patients undergoing treatment. The SC formulation could address these logistical hurdles.
Maintenance of Effective Drug Concentrations
The proposed regimen involves patients completing the bi-weekly IV initiation phase, followed by weekly SC doses of 360 mg. This approach aims to maintain effective drug concentrations of Leqembi, sustaining the clearance of amyloid-beta (Aβ) protofibrils, considered the most toxic form of Aβ plaque. These protofibrils can cause ongoing neuronal injury even after Aβ plaque removal.
Lecanemab's Journey and Market Impact
Lecanemab received breakthrough therapy designation in July 2021 and full FDA approval in July 2023. Despite being better received than aducanumab (Aduhelm), lecanemab has faced challenges in achieving significant market success. Following the discontinuation of aducanumab in January 2024, Biogen shifted its focus to lecanemab and other pipeline treatments like BIIB080 and BIIB113.
Biogen CEO Chris Viehbacher noted that aducanumab paved the way for a new class of drugs and reinvigorated investments in the field, emphasizing the importance of continuous innovation in Alzheimer's treatment.
