What recent disease‑modifying Alzheimer's treatments have been approved by regulators?
Executive summary
Three monoclonal antibody treatments that target amyloid-beta have been approved by U.S. regulators in recent years: aducanumab (Aduhelm) in 2021, lecanemab (Leqembi) in 2023 with updated maintenance dosing approved in 2025, and donanemab (marketed as Kisunla) in 2024 — all indicated for early symptomatic Alzheimer’s with confirmed amyloid pathology and shown to modestly slow clinical decline in trials [1] [2] [3] [4].
1. The new class on the block: anti‑amyloid immunotherapies now bear regulatory approval
Regulators have moved to approve monoclonal antibodies that remove or reduce amyloid plaques in the brain, marking a strategic shift toward disease‑modifying therapy rather than purely symptomatic treatment; the literature and advocacy summaries describe lecanemab and donanemab as the two anti‑amyloid immunotherapies approved in 2023 and 2024 respectively [5] [6], with aducanumab noted as an earlier related approval in 2021 [1].
2. Lecanemab (Leqembi): traditional approval, maintenance dosing refinements
Lecanemab received full FDA approval for early Alzheimer’s disease after trials showed plaque clearance and slowed cognitive decline, and regulators later approved a once‑every‑four‑weeks maintenance dosing option following the initial biweekly regimen based on clinical and extension data showing maintained benefit with continued treatment [2] [3].
3. Donanemab (Kisunla): a second antibody earns its label in 2024
Eli Lilly’s donanemab, marketed as Kisunla, was approved by the FDA in mid‑2024 for people with early symptomatic Alzheimer’s and confirmed amyloid pathology after randomized trials demonstrated a statistically significant slowing of clinical decline on integrated scales over 76 weeks [4] [7], with regulatory documents citing specific cognitive and functional score benefits [4].
4. How much do these drugs change the course of disease? The modest but meaningful effect sizes
Across pivotal trials, the new antibodies have produced modest slowing of decline — reported as roughly 20–30 percent reductions in rate of clinical deterioration depending on the drug and outcome measure — with sources describing lecanemab slowing decline by about 26–30% on key scales and donanemab showing approximately 22% slower decline in the principal study cited at approval [6] [8] [7].
5. Eligibility and logistics: not a universal prescription; diagnostic gates and monitoring
Regulatory approvals have been limited to early‑stage patients who demonstrate elevated brain amyloid, meaning prescriptions typically require biomarker confirmation (amyloid PET or FDA‑cleared blood tests) and ongoing safety monitoring such as periodic MRIs because the therapies are given by infusion and carry safety considerations that clinics must manage [9] [2].
6. The larger landscape and unanswered questions
While these three approvals represent the first disease‑modifying options that alter Alzheimer’s biology and have reshaped treatment discussions [5] [6], the field still contends with open questions about long‑term outcomes, optimal patient selection, safety in broader populations, access barriers, and whether upcoming oral or combinatory approaches will change standards of care [10] [11] [9]. Sources document a robust pipeline and note that many candidate therapies across different mechanisms are advancing through trials, signaling that current approvals are early milestones rather than an endpoint [10] [12].