What new Alzheimer’s drugs received FDA or EMA approvals in 2024–2025 and how effective are they?
This fact-check may be outdated. Consider refreshing it to get the most current information.
Executive summary
In 2024–2025 the main new U.S. approval was Kisunla (donanemab-azbt), granted traditional FDA approval July 2, 2024; regulatory decisions in Europe were mixed, with lecanemab (Leqembi) receiving a contested path and EMA reconsideration in late 2024 while donanemab faced a negative EMA decision in 2025 (FDA press release; EMA developments cited) [1] [2] [3] [4]. Donanemab’s pivotal trial showed modest slowing of clinical decline (iADRS difference 2.92 points at Week 76) and substantial amyloid removal but carried notable safety risks—about 24% ARIA‑E in an earlier trial and routine MRI monitoring is recommended [5] [2] [1].
1. What was actually approved and when — a short timeline
The FDA approved Kisunla (donanemab‑azbt) for treatment of early symptomatic Alzheimer’s disease (mild cognitive impairment and mild dementia with confirmed amyloid) in July 2024, as announced in FDA summaries and press materials [1] [2]. The European regulatory path diverged: lecanemab/Leqembi had a contentious 2023–2024 review with a late 2024 CHMP re‑examination leading to a positive opinion for some patient subgroups, while EMA decisions on donanemab have included negative opinions prompting disappointment from U.S. advocates [3] [4] [6].
2. How effective are these new drugs — what the trials show
Donanemab’s approval rested on a large phase 3 trial (TRAILBLAZER‑ALZ‑2 / Study 1) showing a statistically significant slowing of decline on the Integrated Alzheimer’s Disease Rating Scale (iADRS): a 2.92‑point benefit versus placebo at Week 76, plus component benefits on ADAS‑Cog13 and ADCS‑iADL [2]. Journal reviews and reporting characterize these anti‑amyloid monoclonal antibodies as “modestly” slowing cognitive and functional decline, a phrase used in contemporary coverage of lecanemab and donanemab to signal clinically meaningful but not curative effects [7] [3]. Independent analyses place the clinical effect size as durable but moderate compared with the progressive course of untreated disease [8] [3].
3. Safety tradeoffs — ARIA and monitoring burdens
Donanemab removes amyloid plaques and reduces phosphorylated tau217, but carries risk of amyloid‑related imaging abnormalities (ARIA): an earlier trial reported ARIA‑E in about 24% of treated patients (mostly radiographic and mild–moderate), prompting label changes to mitigate risk via altered titration and MRI monitoring [5] [2]. Regulatory and clinical commentary emphasize black‑box‑level safety concerns for this drug class and the need for infrastructure—frequent MRI scans, specialist centers, and careful patient selection—which limits rollout and strains health systems [5] [7] [9].
4. Who benefits and who’s left out
Approvals were restricted to early symptomatic patients with confirmed amyloid pathology—meaning diagnostic confirmation (PET or validated biomarkers) is required to identify eligible patients [2] [10]. Advocacy groups welcomed FDA action but also warned that trial populations underrepresent many communities and that access will be constrained by clinic capacity, cost, and insurance coverage [11] [7]. Available sources do not detail specific long‑term outcomes beyond the trial windows nor do they provide robust subgroup effectiveness for underrepresented populations (not found in current reporting).
5. Regulatory disagreement and what it signals
FDA and EMA decisions have not been uniform: the FDA granted approval to donanemab while the EMA initially declined lecanemab before reversing course for select patients, and later EMA decisions about donanemab drew criticism from advocacy groups [3] [4]. That split reflects different risk‑benefit thresholds, evidentiary demands for clinical meaningfulness, and varying tolerance for safety signals—an implicit regulatory conservatism in Europe versus a more permissive U.S. stance documented in contemporary analyses [3] [12].
6. Bigger picture — modest progress, large system costs
Experts frame 2024 as a “learning year” for Alzheimer’s therapeutics: new anti‑amyloid monoclonal antibodies demonstrate proof that amyloid removal can slow decline, but effects are moderate and accompanied by significant monitoring and cost burdens [8] [9]. The field is pivoting toward biomarkers, earlier interventions, and combination strategies; regulators have issued new guidance to streamline early‑AD drug development while maintaining biomarker rigor [10].
Limitations: this report uses only the supplied sources and therefore cannot speak to unpublished data, real‑world effectiveness post‑market, or later regulatory changes beyond these citations (limitation noted).