A Study to Assess the Efficacy, Safety, and Tolerability of BIIB080 in Participants With Mild Cognitive Impairment (MCI) Due to Alzheimer's Disease (AD) or Mild Alzheimer's Disease Dementia

• Status: Not yet recruiting
• Trial end date: 2026-12-14
• Target enrollment: 0
• Participant gender: All

Summary

The primary objective of the study is to characterize the dose-response for change from Baseline to Week 76 using Clinical Dementia Rating-Sum of Boxes (CDR-SB). The secondary objectives of the study are to test the superiority of at least one dose arm of BIIB080 versus placebo in change from Baseline to Week 76 using CDR-SB, to evaluate the efficacy of BIIB080 versus placebo in change from Baseline to Week 76 and to evaluate the safety and tolerability of BIIB080 in participants with mild cognitive impairment (MCI) due to Alzheimer's disease (AD) or with mild AD dementia.

• Phase: Phase 2
• Accepts Healthy Volunteers?: No

Details

• Lead Sponsor: Biogen

Criteria

Key Inclusion Criteria:

• Must meet all of the clinical criteria for MCI due to AD or mild AD dementia according to the National Institute on Aging at National Institutes of Health and the Alzheimer's Association (NIA-AA) and must have the following at Screening Visit 1:

1. Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) Delayed Memory Index score of ≤85, indicative of objective evidence of memory impairment

2. CDR global score of 0.5 for MCI due to AD or 0.5 or 1 for mild AD dementia

3. MMSE score of 22 to 30 (inclusive)

4. CDR Memory Box score of ≥0.5

• Evidence of amyloid pathology as measured by positive emission tomography (PET) or cerebrospinal fluid (CSF) sampling

Key Exclusion Criteria:

• Known allergy to BIIB080 or a history of hypersensitivity to any of the inactive ingredients in the drug product

• Previous participation in this study or previous studies with BIIB080

• Use of non-disease-modifying AD medications (including but not limited to donepezil, rivastigmine, galantamine, tacrine, and memantine) at doses that have not been stable for at least 8 weeks prior to Screening Visit 1 and during the screening period up to Study Day 1

• Prior participation in any active or passive immunotherapy study targeting Aβ, unless documentation of receipt of placebo is available

• Prior participation in any passive immunotherapy study targeting tau, unless the last administration occurred 6 months or 5 half-lives, whichever is sooner, prior to Screening or documentation of receipt of placebo is available

• Participation in any study involving an investigational treatment targeting tau that is not an immunotherapy, unless documentation of receipt of placebo is available

• Participation in a study of any other agent(s) [including gene therapy] not included in exclusion criteria 4, 5, and 6 with a purported disease-modifying effect in AD, unless documentation of receipt of placebo is available

• Current use or previous use of medications with a purported disease-modifying effect in AD, outside of investigational studies

• Any vaccination given within 10 days prior to Day -1. Coronavirus disease 2019 (COVID-19) vaccinations using RNA or deoxyribonucleic acid (DNA) technology are allowed during the study, as well as other types of immunization/vaccination/booster, except during the 10 days before and after clinic visits

• Contraindications to having a brain magnetic resonance imaging (MRI) [e.g., MRI-incompatible pacemaker; MRI-incompatible aneurysm clips, artificial heart valves, or other metal foreign body; claustrophobia that cannot be medically managed]. If the MRI compatibility of implanted devices is unknown, the participant must be excluded from the study

• Current enrollment or a plan to enroll in any interventional clinical study in which an investigational treatment or approved therapy for investigational use is administered within 52 weeks prior to the Baseline Visit

NOTE: Other protocol defined Inclusion/Exclusion criteria may apply