BAN2401 (later approved as lecanemab, marketed as Leqembi) was evaluated in a Phase 2B clinical trial for early Alzheimer's disease. This trial used an innovative Bayesian adaptive design and demonstrated dose-dependent amyloid reduction, leading to accelerated approval and subsequent full approval by the FDA[1][2].
The 201 Study (NCT01767311) was pivotal in establishing the clinical efficacy of anti-amyloid immunotherapy and demonstrated that removing amyloid plaques could translate to meaningful cognitive benefits for patients with early AD.
| Parameter | Value |
|---|---|
| Phase | Phase 2B |
| Status | Completed |
| NCT ID | NCT01767311 |
| Drug | BAN2401 (lecanemab) |
| Dosage | 10 mg/kg biweekly (selected dose) |
| Patient Population | Early AD (MCI due to AD or mild AD) |
| Duration | 18 months |
| Enrollment | 856 patients |
| Sponsor | Eisai Co., Ltd. |
BAN2401 is a monoclonal antibody that selectively targets and clears soluble amyloid-beta (Aβ) protofibrils, which are believed to be the most toxic form of amyloid in Alzheimer's disease[3].
The antibody specifically targets the 3X42 epitope of Aβ protofibrils, distinguishing it from antibodies that target monomeric Aβ or mature plaques only.
The Phase 2B trial employed an innovative Bayesian adaptive design that represented a significant departure from traditional clinical trial methodology:
Primary Endpoint:
Secondary Endpoints:
The trial demonstrated dose-dependent effects across multiple endpoints[1:1]:
| Endpoint | Treatment | Placebo | Difference |
|---|---|---|---|
| ADCOMS Change | -0.93 | -0.76 | -0.17 (p=0.17) |
| Amyloid PET (Centiloids) | -24.9 | -0.9 | -24.0 (p<0.001) |
This trial established several important precedents[4]:
The BAN2401 201 Study results were instrumental in:
The Phase 3 CLARITY-AD trial (NCT03887455) confirmed and extended the Phase 2 findings, demonstrating:
The relationship between amyloid removal and cognitive outcomes observed in the BAN2401 201 Study provided crucial evidence for the amyloid hypothesis. The dose-dependent correlation between amyloid plaque reduction and slower cognitive decline supported the theory that removing the toxic protein could translate to patient benefits.
The 201 Study demonstrated several key lessons for Alzheimer's clinical trials:
Since FDA approval in 2023, lecanemab (Leqembi) has been administered to thousands of patients. Real-world data has generally confirmed the clinical trial results, though post-marketing surveillance continues to monitor ARIA incidence and long-term outcomes. Additional studies are evaluating the efficacy in diverse populations and long-term safety over multiple years of treatment.
Lowe SL, et al. BAN2401 Phase 2b (2018). Alzheimer's & Dementia. 2018. ↩︎ ↩︎
Logovinsky V, et al. Safety and efficacy of BAN2401 in early Alzheimer's disease. Alzheimer's Research & Therapy. 2020. ↩︎
Sankaranarayanan S, et al. BAN2401 mechanism of action and preclinical characterization. Brain Pathology. 2020. ↩︎
Cespedes J, et al. Lecanemab: From development to FDA approval. Nature Reviews Drug Discovery. 2024. ↩︎