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# FDA Full Approval for Eisai’s Leqembi
- URL: https://www.fdaweb.com/fda-full-approval-for-eisais-leqembi/
- Published: 2023-07-10T12:00:00.000Z
- Updated: 2026-09-14T18:42:57.000Z
- Author: David McFarland
- Tags: Drugs, #legacy-id-D5154824

FDA has converted from accelerated approval to full approval Eisai’s Alzheimer’s disease drug Leqembi (lecanemab-irmb). The drug received accelerated approval in January. FDA [says](https://www.fda.gov/news-events/press-announcements/fda-converts-novel-alzheimers-disease-treatment-traditional-approval?ref=fdaweb.com) it was converted to traditional approval following a determination that a confirmatory trial verified clinical benefit, making it the first drug in its class to be converted to full approval.

The agency statement says the drug works by reducing amyloid plaques that form in the brain, which the statement says is a “defining pathophysiological feature of the disease.”

Leqembi’s efficacy was evaluated in the Phase 3 CLARITY AD trial, FDA says. In the trial, treatment was initiated in patients with mild cognitive impairment or mild dementia stage of disease, it says.

“Leqembi demonstrated a statistically significant and clinically meaningful reduction of decline from baseline to 18 months on the primary endpoint,” FDA says. “Statistically significant differences between treatment groups were also demonstrated on all secondary endpoints.” The primary and secondary endpoints involved dementia, cognition, and activities of daily living rating scales.

The agency’s Peripheral and Central Nervous System Drug Advisory Committee discussed the confirmatory study on 6/9 and voted that the study results verified the benefit of Leqembi for the intended use.

The statement says Leqembi’s most common side effects were headache, infusion-related reactions, and amyloid-related imaging abnormalities, which most commonly present as temporary swelling in areas of the brain seen in imaging studies.

The labeling says Leqembi should be initiated in patients with mild cognitive impairment or mild dementia stage of Alzheimer’s. It says there are no safety or effectiveness data on initiating treatment at earlier or later stages of the disease than were studied.