Clinically Important Benefits and Harms of Monoclonal Antibodies Targeting Amyloid for the Treatment of Alzheimer Disease: A Systematic Review and Meta-Analysis.
Level 1 - systematic review of randomized trials
Systematic review and meta-analysis of randomized controlled trials
PubMed 38253509 · doi:10.1370/afm.3050
What was done
A systematic review and random-effects meta-analysis evaluated the benefits and harms of anti-amyloid monoclonal antibodies in patients with Alzheimer dementia. Researchers searched PubMed, Cochrane CENTRAL, five trial registries, and reference lists for randomized controlled trials comparing an anti-amyloid antibody to placebo at doses used in phase 3 trials or FDA approval. Two independent reviewers extracted data on cognitive, functional, and safety outcomes. Mean differences were compared against established minimal clinically important difference (MCID) thresholds.
What was found
The analysis included 19 publications with 23,202 participants across 8 antibodies (including lecanemab, aducanumab, and donanemab). Small improvements favoring treatment were observed for ADAS-Cog-11 to -14 score (standardized mean difference = -0.07; 95% CI, -0.10 to -0.04), Mini Mental State Examination score (0.32 points; 95% CI, 0.13 to 0.50), Clinical Dementia Rating-Sum of Boxes score (mean difference = -0.18 points; 95% CI, -0.34 to -0.03), and combined functional scores (standardized mean difference = 0.09; 95% CI, 0.05 to 0.13). None of the changes exceeded the MCID. Harms included increased risks of amyloid-related imaging abnormalities (ARIA)-edema (relative risk [RR] = 10.29; number needed to harm [NNH] = 9), ARIA-hemorrhage (RR = 1.74; NNH = 13), and symptomatic ARIA-edema (RR = 24.3; NNH = 86).
Why it matters
This review evaluates statistical trial endpoints against clinical relevance standards, demonstrating that across the drug class, modest scale changes do not reach clinically meaningful thresholds for patients despite causing frequent imaging abnormalities.
Limits
The analysis pools multiple distinct antibody molecules that have differing binding targets and trial designs. The findings rely on specific MCID definitions from the literature, which may vary across clinical contexts. The abstract does not report study follow-up duration or individual trial risk-of-bias assessments.
Cited by
- supports There are currently no meaningful disease-modifying treatments for neurodegenerative diseases like Alzheimer's and Parkinson's disease that address the underlying disease process.