FDA Accelerates Approval of a New Alzheimer’s Disease Drug, Leqembi

Based on the results of a double-blind, placebo-controlled, the FDA granted the accelerated approval of Leqembi for Alzheimer’s disease, making it the second approved medication targeting the pathophysiology of the illness. The approval on January 6, 2023, marked another milestone in Alzheimer’s disease care.

The study, which laid the foundation for accelerated approval, recruited 856 patients with Alzheimer's disease who had mild cognitive impairment or mild dementia with amyloid beta pathology. Throughout the study, researchers determined that there was a dose- and time-dependency between the medication and the presence of beta-amyloid plaques.

A 10 mg/kg infusion of Leqembi every two weeks yielded statistically significant reductions in brain amyloid plaques compared to the original levels. Concurrently, the group receiving the placebo experienced no reduction in plaque.

Despite the positive results associated with the medication, the FDA warns against some side effects, including amyloid-related imaging abnormalities (ARIA), which are linked to swelling in the brain. These symptoms often resolve themselves but, in some cases, can cause headaches, confusion, visual changes, nausea, seizures, and more. Providers are also encouraged to monitor patients for flu-like symptoms, nausea, vomiting, and blood pressure changes associated with the infusion process.

“Alzheimer’s disease immeasurably incapacitates the lives of those who suffer from it and has devastating effects on their loved ones,” said Billy Dunn, MD, director of the Office of Neuroscience in the FDA’s Center for Drug Evaluation and Research, in the press release. “This treatment option is the latest therapy to target and affect the underlying disease process of Alzheimer’s, instead of only treating the symptoms of the disease.”

It is estimated that approximately 6.5 million people in the United States have Alzheimer’s disease, accounting for 60–80% of all dementia cases. The WHO estimates that the global dementia incidence is 55 million, with many sources, including Alzheimer's Disease International, estimating that the number will double every 20 years. These statistics indicate a significant need for additional treatments, such as Leqembi and other recently approved therapies, for Alzheimer’s Disease and other neurodegenerative disorders.

Providers can now prescribe this medication to eligible patients, being mindful to monitor and report any side effects or adverse reactions. As the rollout of this medicine begins, the FDA will closely monitor the outcomes and await the results of phase IV confirmatory trials required after accelerated approval. Future research may consider testing this medication in later-stage Alzheimer's patients.