What Anti-Amyloid Drugs Are FDA Approved?

October 10, 2025 •

3 min read

According to the Alzheimer's Association, millions of Americans are affected by Alzheimer's, and recent breakthroughs have led to the approval of several new therapies aimed at the underlying pathology. This article explores what anti-amyloid drugs are FDA approved, detailing their mechanism of action, key clinical data, and safety profiles for treating early-stage Alzheimer's disease.

Quick Summary

The FDA has granted traditional approval to lecanemab (Leqembi) and donanemab (Kisunla) for early Alzheimer's disease, while the previously approved aducanumab (Aduhelm) was later discontinued.

Key Points

FDA Approval for Anti-Amyloid Drugs: The FDA has granted traditional approval to two anti-amyloid drugs for early-stage Alzheimer's: lecanemab (Leqembi) and donanemab (Kisunla).
Discontinuation of Aducanumab: The first anti-amyloid drug, aducanumab (Aduhelm), received a controversial accelerated approval in 2021 but was discontinued by its manufacturer in 2024.
Mechanism of Action: Both lecanemab and donanemab are monoclonal antibodies that target and clear amyloid-beta plaques from the brain, potentially slowing the progression of the disease.
Clinical Efficacy: Clinical trials demonstrated that both lecanemab and donanemab can slow cognitive decline in patients with mild cognitive impairment or mild dementia due to Alzheimer's.
Risk of ARIA: All anti-amyloid monoclonal antibodies carry a boxed warning for Amyloid-Related Imaging Abnormalities (ARIA), which can cause brain swelling or small bleeds, requiring careful MRI monitoring.
Indication: These therapies are intended for patients with early-stage Alzheimer's disease who have confirmed amyloid plaques in their brains.
Dosage and Administration: Lecanemab and donanemab are administered intravenously (IV) on specific schedules.

The Anti-Amyloid Approach to Alzheimer's Disease

For decades, Alzheimer's disease (AD) research has focused on the amyloid hypothesis, which posits that the accumulation of sticky beta-amyloid plaques in the brain is a central driver of the disease's progression. This build-up is thought to trigger a cascade of events leading to the formation of tau tangles, nerve cell death, and, ultimately, cognitive decline. Anti-amyloid drugs, specifically monoclonal antibodies, are designed to target and clear these plaques, offering a disease-modifying approach rather than just symptomatic relief. While older medications focused on symptom management, these newer therapies aim to slow the underlying disease process itself, representing a significant shift in treatment strategy.

The Rise of Monoclonal Antibodies

Monoclonal antibodies are laboratory-produced molecules engineered to mimic the body's immune system by targeting a specific antigen. In the case of anti-amyloid drugs, the antibodies bind to beta-amyloid proteins.

FDA Approved Anti-Amyloid Drugs

Two anti-amyloid monoclonal antibody therapies have traditional FDA approval for treating early-stage Alzheimer's disease. Lecanemab (Leqembi) received traditional approval in July 2023, targeting amyloid-beta protofibrils and showing a slowing of cognitive decline in trials. It is administered via IV infusion on a specific schedule. Donanemab (Kisunla) received traditional approval in July 2024, targeting established beta-amyloid plaques. The Phase 3 TRAILBLAZER-ALZ 2 trial showed it slowed clinical decline in early symptomatic AD. It is administered via IV infusion on a specific schedule, and treatment may stop once amyloid levels are below a threshold. Both are approved for patients with mild cognitive impairment or mild dementia with confirmed amyloid pathology.

The History and Discontinuation of Aducanumab

Aducanumab (Aduhelm) was the first anti-amyloid drug to receive accelerated approval in June 2021. Its approval was controversial, based on amyloid plaque reduction despite conflicting evidence of meaningful clinical benefit. Limited adoption and insurance coverage, along with mixed efficacy data, led to the manufacturer discontinuing the drug in early 2024 for commercial reasons.

Comparison of FDA-Approved Anti-Amyloid Drugs


Feature	Lecanemab (Leqembi)	Donanemab (Kisunla)	Aducanumab (Aduhelm)
FDA Approval Status	Traditional (July 2023)	Traditional (July 2024)	Discontinued (2024)
Target	Amyloid-beta protofibrils	N3pG-modified beta-amyloid plaques	General amyloid-beta plaques
Administration	IV infusion on a specific schedule	IV infusion on a specific schedule, can be stopped based on amyloid levels	IV infusion on a specific schedule
Confirmed Efficacy	Yes, slowed cognitive decline in early AD	Yes, slowed cognitive decline in early AD	Conflicting data, minimal clinical benefit
Risk of ARIA	Yes, included in boxed warning	Yes, included in boxed warning	Yes, noted in prescribing info

Safety Concerns: Amyloid-Related Imaging Abnormalities (ARIA)

A significant shared risk for these anti-amyloid therapies is Amyloid-Related Imaging Abnormalities (ARIA). ARIA refers to brain swelling (ARIA-E) or small brain bleedings (ARIA-H) that can occur during treatment.

Monitoring: Regular MRI scans are required during treatment to monitor for ARIA.
Symptoms: ARIA can be asymptomatic but may cause symptoms like headache or confusion. Severe or life-threatening hemorrhages are rare.
Risk Factors: The risk is higher for individuals with the APOE4 gene.

Conclusion: The Future of Anti-Amyloid Therapy

The traditional FDA approvals of lecanemab and donanemab are significant advancements, offering new options to slow the progression of early Alzheimer's. These therapies represent progress from the earlier experience with aducanumab, highlighting the importance of robust clinical data and ongoing safety monitoring for ARIA. For more information on amyloid-targeting treatments and Alzheimer's disease research, you can visit the Alzheimer's Association.

Frequently Asked Questions

While both are anti-amyloid drugs, lecanemab (Leqembi) and donanemab (Kisunla) target slightly different forms of amyloid and have different dosing schedules. Lecanemab targets protofibrils, whereas donanemab targets established plaques and is administered on a schedule that may allow for a stop in treatment once plaques are cleared.

No, anti-amyloid drugs are not a cure for Alzheimer's disease. They are disease-modifying therapies designed to slow the rate of cognitive and functional decline in patients with early-stage Alzheimer's, but they do not reverse existing damage.

These therapies are typically indicated for patients in the early stages of Alzheimer's disease, specifically those with mild cognitive impairment or mild dementia, and who have confirmed amyloid-beta pathology in their brains through testing like a PET scan or spinal tap.

ARIA stands for Amyloid-Related Imaging Abnormalities, which are side effects involving temporary brain swelling (ARIA-E) or microhemorrhages (ARIA-H). To manage ARIA, patients undergo periodic MRI scans, especially during the initial treatment period. The risk is elevated in individuals with the APOE4 gene.

Aducanumab was discontinued due to commercial reasons, stemming from its controversial accelerated approval, mixed efficacy data, high cost, and limited patient adoption. Concerns over its clinical benefit and safety compared to its cost also led to limited insurance coverage.

Lecanemab (Leqembi) and donanemab (Kisunla) are both administered intravenously (IV). They are given on specific schedules as prescribed by a healthcare professional.

No. The Cleveland Clinic explicitly states that patients should not take more than one anti-amyloid therapy simultaneously, as their combined safety and efficacy have not been studied.