Cochrane Review Reignites Long-Running Scientific Battle Over Alzheimer’s Amyloid Drugs

A newly released Cochrane review has reopened one of the most contentious debates in modern medicine: whether amyloid-targeting drugs for Alzheimer’s disease deliver benefits meaningful enough to justify their costs and risks. The analysis arrives as the field simultaneously absorbs fresh data from another Elevidys gene therapy trial and watches federal regulators reconsider their stance on compounded peptide therapies.

The Cochrane review, produced by the internationally respected evidence-synthesis organization that sets the gold standard for medical meta-analyses, pooled data from multiple randomized controlled trials of anti-amyloid antibodies. Its authors found that while these drugs demonstrably reduce amyloid plaque burden in the brain and produce statistically significant improvements on cognitive scales such as the Clinical Dementia Rating-Sum of Boxes, the magnitude of those improvements may not cross the minimum threshold patients and caregivers would perceive as meaningful. The review also drew attention to the well-documented risk of amyloid-related imaging abnormalities, or ARIA, which can manifest as brain swelling or microhemorrhages and has been linked to patient deaths in clinical trials.

The findings have reignited a schism that has divided neurologists, geriatricians, and health economists since the FDA’s controversial 2021 approval of Aduhelm, the first amyloid-targeting antibody, which was ultimately withdrawn from the market. Leqembi, co-developed by Eisai and Biogen, received traditional approval in 2023, followed by Eli Lilly’s Kisunla in 2024. Medicare currently covers both treatments, with annual drug costs ranging roughly $26,000 to $32,000 before accounting for required MRI monitoring and infusion logistics. Proponents argue that even modest slowing of decline offers value to patients in the earliest stages of Alzheimer’s, while critics contend that the benefits are clinically imperceptible and the safety profile unacceptable given the price.

Beyond Alzheimer’s, the broader biotech landscape faces its own reckonings. Sarepta’s Elevidys, the first gene therapy approved for Duchenne muscular dystrophy, has come under intensified scrutiny following patient deaths reported earlier this year, complicating interpretation of new efficacy data. Meanwhile, the FDA’s reconsideration of compounded peptides signals potential shifts in how the agency polices a booming market that includes semaglutide and tirzepatide copies, as well as newer research peptides marketed through wellness clinics. How regulators balance access, safety, and pharmaceutical industry exclusivity will shape patient options heading into 2026.