Critical evaluation of real-world evidence of repurposable medicines in the Alzheimer's disease drug development pipeline using a target trial emulation

INTRODUCTION: Repurposing Food and Drug Administration (FDA)-approved drugs could accelerate treatment development for Alzheimer's disease (AD). METHODS: Using the MarketScan claims database (2011 to 2020), we applied a trial emulation approach in two base cohorts: (1) individuals with mild cognitive impairment (MCI cohort) and (2) individuals aged ≥70 years (over-70 cohort). We evaluated drugs represented in clinical trials for AD, comparing them with same-class or active comparators. Covariate-adjusted hazard ratios (HRs) were estimated using inverse-probability-weighted Cox models. RESULTS: A total of 6 out of 38 (16%) drugs in the MCI cohort and 10 out of 53 (19%) drugs in the over-70 cohort were associated with a lower AD incidence versus same-class comparators. Active comparator analyses indicated that bupropion (vs escitalopram; HR 0.57, 95% confidence interval [CI] [0.49, 0.66]), trazodone (vs sertraline; HR 0.82, 95% CI [0.74, 0.91]), venlafaxine (vs escitalopram; 0.72, 95% CI [0.62, 0.84]), and zolpidem (vs lorazepam; HR 0.69, 95% CI [0.56, 0.85]) were associated with a lower AD incidence in the MCI cohort; these four plus liraglutide were associated with a lower incidence of AD dementia in the over-70 cohort (vs metformin; HR 0.74, 95% CI [0.59, 0.93]). DISCUSSION: This is the first comprehensive set of trial emulations for FDA-approved drugs that are represented in AD trials. Findings may inform future trial designs. Highlights: Repurposing FDA-approved drugs originally developed for other diseases could accelerate treatment development for AD. We identified repurposable drugs that are in current or complete clinical trials of AD and emulated trials for these agents using a large-scale insurance claims-based database. Among 54 drugs evaluated, 6/38 (16%) drugs in the MCI cohort and 10/53 (19%) in the over-70 cohort were associated with reduced AD incidence versus same-class comparators. Active comparator analyses indicated that bupropion, trazodone, venlafaxine, and zolpidem were associated with reduced AD incidence in the MCI cohort; these four plus liraglutide were associated with a lower incidence of AD dementia in the over-70 cohort. A minority of repurposed table drugs that are in current or completed clinical trials for AD and meet criteria for inclusion in this study showed no effect in our trial emulation studies. This is the first comprehensive set of trial emulations for FDA-approved drugs that are represented in AD trials. Building on our findings, integrating real-world evidence can inform future trials and accelerate drug development for AD.