What reliable treatments and approved drugs currently exist for Alzheimer’s disease?
Executive summary
Two categories of reliable, FDA‑approved treatments exist for Alzheimer’s disease today: longstanding symptomatic therapies that can modestly improve cognition or behavior, and a new class of anti‑amyloid monoclonal antibodies that have been shown to slow decline in people with early disease; both approaches have limits, specific eligibility rules and safety trade‑offs [1] [2] [3]. Symptom‑targeted drugs remain the mainstay for moderate‑to‑severe disease while lecanemab (Leqembi) and donanemab (Kisunla) now offer, for eligible patients, modest disease‑modifying effects when started in mild stages and after confirmation of amyloid pathology [4] [2] [3].
1. Symptom‑directed medicines that clinicians have relied on for years
Cholinesterase inhibitors and the NMDA antagonist memantine are the established, FDA‑approved medications used to treat cognitive symptoms and functional decline in Alzheimer’s disease, and while they do not cure the disorder they can slow decline or reduce confusion in some patients [1] [4]. Memantine (Namenda®) is explicitly approved for moderate to severe Alzheimer’s disease and can be given alone or with a cholinesterase inhibitor to address symptoms mediated by glutamate dysregulation [4]. National Alzheimer’s organizations and clinical summaries continue to categorize these drugs as symptomatic therapies rather than disease‑altering cures [1].
2. Anti‑amyloid monoclonal antibodies that modify disease in early stages
Two monoclonal antibodies—lecanemab (Leqembi®) and donanemab (Kisunla™)—have been approved by the FDA for adults with early symptomatic Alzheimer’s disease and are intended for people with mild cognitive impairment or mild dementia who have confirmed amyloid pathology [2] [3] [5]. Lecanemab was converted from accelerated to traditional approval after a confirmatory Phase 3 trial verified clinical benefit and is described by the FDA as the first amyloid‑directed antibody to achieve that conversion [2]. Donanemab received traditional approval based on trials showing statistically significant slowing of clinical decline over 18 months in populations with confirmed amyloid [3] [6].
3. How these new drugs work, who qualifies and how they’re given
Both lecanemab and donanemab target amyloid‑beta plaques and are administered intravenously on a schedule defined in their labeling—lecanemab by the regimen in its approval and donanemab as a once‑monthly IV infusion—with regulatory guidance stressing initiation only in the early, mild stages and after confirmation of elevated brain amyloid by PET or CSF testing [5] [3] [2]. Regulatory materials and Alzheimer organizations emphasize there are no safety or effectiveness data for starting these therapies outside the studied early‑stage population, meaning eligibility depends on diagnostic confirmation and disease stage [2] [5].
4. Magnitude of benefit and safety caveats
Clinical results show modest but measurable slowing of decline: donanemab reduced clinical decline by a roughly 22–35% relative measure in trial subsets over 18 months and lecanemab demonstrated verified clinical benefit in a large Phase 3 trial, but both are described as producing modest gains rather than halting disease [6] [2] [7]. Reporting and expert commentary caution about safety risks and practical limits—these therapies require specialized testing, infusion infrastructure and monitoring, and questions remain about which patients benefit most and for how long, with public reporting noting risks alongside the benefits [8] [9].
5. Treatments for neuropsychiatric symptoms and pipeline developments
For behavioral symptoms, the FDA has approved brexpiprazole (Rexulti®) for agitation associated with dementia due to Alzheimer’s as a specific indication, while other agents are used off‑label and clinicians are urged to try non‑drug strategies first [10] [9]. Meanwhile, companies are pursuing new approvals for agitation—Axsome’s AXS‑05 is under FDA Priority Review for Alzheimer’s‑related agitation with a regulatory action date in 2026—highlighting an active pipeline for symptomatic management [11] [12].
6. Bottom line: who benefits, and where the uncertainty lies
Reliable, FDA‑approved options now include traditional symptomatic drugs for mild‑to‑severe stages, a new set of anti‑amyloid monoclonals for carefully selected patients with early disease and at least one approved drug for agitation, but clinicians and patients must weigh modest average benefits, eligibility constraints (amyloid confirmation and disease stage), monitoring requirements and safety considerations when deciding on treatment [1] [2] [3] [10]. Reporting from regulators, advocacy groups and news outlets converges on cautious optimism: meaningful progress has arrived, but it is incremental and conditioned on careful patient selection and follow‑up [2] [13] [6].