US FDA Approves New Drug to Treat Alzheimer's Disease

Jace Dela Cruz, Tech Times 10 January 2023, 07:01 pm

The US Food and Drug Administration (FDA) has approved a new drug that treats Alzheimer's disease through the Accelerated Approval pathway, as per the agency's press release on Jan. 6.

The new drug called Leqembi (lecanemab-irmb) is the second in a newly-approved class of medications for Alzheimer's disease that addresses its basic pathophysiology.

"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," Billy Dunn, director of the Office of Neuroscience in FDA Center for Drug Evaluation and Research, said in a statement.

(Photo : Steve Buissinne/ Pixabay)

Accelerated Approval Pathway

Alzheimer's is a progressive brain disorder that affects around 6.5 million people in the US. It gradually impairs memory skills and the capacity to perform simple tasks.

FDA's Accelerated Approval process enables the agency to approve medications for serious conditions especially when a medical need is not addressed and an existing drug is proven to have an impact on a surrogate endpoint that is likely to reap clinical benefits for patients. This pathway ultimately allowed for the approval of Leqembi.

The agency expects to receive more data once the findings of the Phase 3 randomized, controlled clinical trial for the drug are complete.

The patients have undergone treatment once they have been confirmed to have amyloid beta pathology and mild dementia.

Results of the Treatment

Patients taking the recommended dose of lecanemab experienced a significant, dose- and time-dependent reduction in amyloid beta plaque.

They took 10 mg/kg every two weeks, and compared to the placebo arm, which did not experience any reduction in amyloid beta plaque, they experienced a statistically significant decrease in brain amyloid plaque from baseline to Week 79.

These findings led to Leqembi's expedited approval, which is justified by the reported decline in amyloid-beta plaque levels, a sign of Alzheimer's disease.

The amount of amyloid beta plaque in the brain was measured using positron emission tomography (PET) imaging to compare the levels in a composite of brain regions predicted to be adversely impacted by the pathology of Alzheimer's disease to regions expected to be unaffected by such pathology.

Warning Label

FDA notes that Leqembi carries a warning label for amyloid-related imaging abnormalities (ARIA), which occur in antibodies from this class.

ARIA is normally asymptomatic, however, it can occasionally result in fatal cases. The most typical sign of ARIA is a brief enlargement of certain brain regions, which normally goes away on its own and may be followed by microscopic bleeding spots on or inside the brain.

On the other hand, some people could encounter symptoms like migraines, disorientation, dizziness, seizures, changes in vision, and nausea, according to FDA.

Leqembi also carries the risk of infusion-related responses, which can result in flu-like symptoms, vomiting, nausea, and fluctuations in blood pressure.

FDA said that the most reported side effects of the new drug include headaches, infusion-related reactions, and ARIA.

According to the labeling, the drug should be given to individuals with moderate cognitive impairment or mild dementia stage of the disease - the population examined in Leqembi's clinical trials.

Additionally, the labeling notes that there are no safety or efficacy data regarding the start of treatment at earlier or later stages of the disease than were examined.