FDA Grants Priority Review to Leqembi for Traditional Approval

The FDA has accepted Eisai’s supplemental biologics license application (sBLA) for Biogen/Eisai’s Leqembi (lecanemab-irmb) to convert the accelerated approval to a traditional approval to treat patients with Alzheimer’s disease. The FDA has assigned a Prescription Drug User Fee Act (PDUFA) action date of July 6, 2023. The FDA is currently planning to hold an advisory committee but has not yet announced the date of the meeting.

Last week, the Institute for Clinical and Economic Review (ICER), in an updated evidence report, calculated a health-benefit price benchmark (HBPB) of between $8,900 and $21,500 per year, which is lower than the Leqembi’s wholesale acquisition cost of $26,500 a year. ICER analysts said that Leqembi would need a 66% to 19% discount from its wholesale acquisition cost to fall within commonly used cost-effectiveness thresholds.

Related: Updated ICER Analysis Shows Leqembi Still Not Cost-Effective

The FDA issued an accelerated approval for Leqembi in January 2023. Leqembi it is a humanized immunoglobulin gamma 1 (IgG1) monoclonal antibody approved to treat patients with mild cognitive impairment or mild dementia. The accelerated approval was based on phase 2 data that demonstrated that Leqembi reduced the accumulation of amyloid plaque in the brain. The FDA has determined that the results of phase 3 Clarity AD can serve as the confirmatory study.

Clarity AD was an 18-month trial that enrolled 1,795 people aged 50 to 90, and results were presented at the 2022 Clinical Trials on Alzheimer’s Disease (CTAD) conference. The modified intention-to-treat population included 1,734 participants with 859 in the Leqembi group and 875 in the placebo group. Leqembi slowed decline of cognitive function by 26% on the AD Assessment Scale - Cognitive Subscale 14 at 18 months. In the AD Composite Score, Leqembi slowed disease progression by 24% at 18 months.

But Leqembi resulted in infusion-related reactions in 26.4% of the patients and amyloid-related imaging abnormalities with edema or effusions in 12.6% of patients. Serious adverse events occurred in 14.0% of the participants in the Leqembi group and 11.3% of those in the placebo group. The most commonly reported serious adverse events were infusion-related reactions. Adverse events leading to discontinuation of the trial agent occurred in 6.9% of the participants in the Leqembi group and 2.9% of those in the placebo group.