Eisai Biogen’s LEQEMBI Subcutaneous Autoinjector Wins NMPA Priority Review in China

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

ItemDetail
CompaniesEisai Co., Ltd. (global development lead) × Biogen Inc. (NASDAQ: BIIB)
AgencyNMPA (China)
AssetLEQEMBI (lecanemab) – Anti-amyloid beta (Aβ) protofibril antibody
FormulationSubcutaneous autoinjector (SC-AI)
Review StatusPriority Review designated
China LaunchIV formulation approved June 2024; SC-AI under review
US StatusSC-AI approved September 2025

Product Profile & Administration Evolution

FeatureIV Formulation (Current)SC-AI (Pending)Patient Impact
AdministrationIntravenous infusion (bi-weekly)Subcutaneous autoinjector (bi-weekly)Home administration eliminates 4-6 hour clinic visits
SettingHospital infusion centerHome or caregiver-administeredReduced healthcare system burden; improved access for rural patients
Dosing FrequencyEvery 2 weeksEvery 2 weeksMaintained efficacy with convenience upgrade
Amyloid TargetAβ protofibrils (most toxic species)Same mechanismProven disease-modifying efficacy (Clarity AD trial)

Commercial Structure & China Strategy

ResponsibilityPartyStrategic Rationale
Global Development & RegulatoryEisai (final decision authority)Integrated Alzheimer’s expertise; Clarity AD trial leadership
China CommercializationEisai lead with Biogen supportEisai’s 20+ year China presence and neurology relationships
Co-PromotionBiogen participationLeverages 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

FactorMarket Impact
China Alzheimer’s Burden>10 million patients; fastest-aging population globally; diagnosis rates rising with biomarker availability
LEQEMBI IV UptakeFirst disease-modifying Alzheimer’s therapy in China; SC-AI addresses infusion capacity constraints in tier-2/3 cities
Donanemab CompetitionEli Lilly’s rival amyloid antibody approved in China January 2025; SC formulation critical differentiator for adherence and access
Reimbursement PathwayNRDL inclusion for IV formulation 2024; SC-AI likely premium pricing for administration convenience

Development & Launch Timeline

PhaseActivityTimeline
CurrentNMPA Priority Review ongoingQ1-Q2 2026
ApprovalSC-AI marketing authorization anticipatedH2 2026
LaunchHome administration training and distribution rollout2026-2027
ExpansionPotential 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