Eisai Co., Ltd. and Biogen Inc. (NASDAQ: BIIB) announced that the Biologics License Application (BLA) for LEQEMBI (lecanemab) subcutaneous autoinjector (SC-AI) has been granted Priority Review by China’s National Medical Products Administration (NMPA). The home-administered anti-amyloid Alzheimer’s therapy, already approved in the US (September 2025), would reduce clinic visit burden for Chinese patients with mild cognitive impairment and mild dementia due to Alzheimer’s disease.
Regulatory Milestone
Item
Detail
Companies
Eisai Co., Ltd. (global development lead) × Biogen Inc. (NASDAQ: BIIB)
IV formulation approved June 2024; SC-AI under review
US Status
SC-AI approved September 2025
Product Profile & Administration Evolution
Feature
IV Formulation (Current)
SC-AI (Pending)
Patient Impact
Administration
Intravenous infusion (bi-weekly)
Subcutaneous autoinjector (bi-weekly)
Home administration eliminates 4-6 hour clinic visits
Setting
Hospital infusion center
Home or caregiver-administered
Reduced healthcare system burden; improved access for rural patients
Dosing Frequency
Every 2 weeks
Every 2 weeks
Maintained efficacy with convenience upgrade
Amyloid Target
Aβ protofibrils (most toxic species)
Same mechanism
Proven disease-modifying efficacy (Clarity AD trial)
Commercial Structure & China Strategy
Responsibility
Party
Strategic Rationale
Global Development & Regulatory
Eisai (final decision authority)
Integrated Alzheimer’s expertise; Clarity AD trial leadership
China Commercialization
Eisai lead with Biogen support
Eisai’s 20+ year China presence and neurology relationships
Co-Promotion
Biogen participation
Leverages Biogen’s rare disease and neurology infrastructure
Priority Review Significance: NMPA accelerated timeline (typically 6-12 months vs. standard 12-18 months) reflects high unmet need in Alzheimer’s and regulatory alignment with US FDA approval
Market Context & Strategic Implications
Factor
Market Impact
China Alzheimer’s Burden
>10 million patients; fastest-aging population globally; diagnosis rates rising with biomarker availability
LEQEMBI IV Uptake
First disease-modifying Alzheimer’s therapy in China; SC-AI addresses infusion capacity constraints in tier-2/3 cities
Donanemab Competition
Eli Lilly’s rival amyloid antibody approved in China January 2025; SC formulation critical differentiator for adherence and access
Reimbursement Pathway
NRDL inclusion for IV formulation 2024; SC-AI likely premium pricing for administration convenience
Development & Launch Timeline
Phase
Activity
Timeline
Current
NMPA Priority Review ongoing
Q1-Q2 2026
Approval
SC-AI marketing authorization anticipated
H2 2026
Launch
Home administration training and distribution rollout
2026-2027
Expansion
Potential indication expansion to preclinical AD (AHEAD study)
2027+
Forward‑Looking Statements This brief contains forward‑looking statements regarding LEQEMBI SC-AI NMPA approval timelines, China market penetration for subcutaneous Alzheimer’s therapy, and Eisai-Biogen commercial execution. Actual results may differ due to NMPA review delays, reimbursement negotiation outcomes, and competitive dynamics with donanemab and emerging anti-tau therapies.-Fineline Info & Tech