In the ongoing fight to treat Alzheimer’s disease, the U.S. Food and Drug Administration (FDA) approved the drug Leqembi as a possible treatment on Jan. 6. Leqembi is the second drug of a new category of approved medications to treat the disease, according to a press release from the FDA. The approval is under the FDA’s Accelerated Approval pathway, which approves drugs for serious conditions where there is an unmet medical need.
“Alzheimer’s disease immeasurably incapacitates the lives of those who suffer from it,” says Billy Dunn, 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.”
While this may sound like promising news, you may be wondering: What is this drug and how does it slow cognitive decline?
Leqembi’s Main Trial
The drug targets the “fundamental pathophysiology” of Alzheimer’s, or the changes seen at a cellular level. Leqembi works to reduce the amount of beta-amyloid present in the brain, which is a main identifier of Alzheimer’s.
Plaques can form in the brain when pieces of beta-amyloid, a protein, clump together. Excessive buildup blocks cell-to-cell signaling at synapses in the brain, as well as other neurological functions, resulting in Alzheimer’s disease.
In a study of 856 participants with Alzheimer’s, researchers provided treatment to patients that suffered from mild cognitive impairment or the mild dementia stage of Alzheimer’s. Of note, the participants had to have the presence of amyloid beta pathology.
The results of the study showed a statistically significant reduction in the amount of amyloid beta plague in patients who received the treatment when compared to the placebo group. The placebo group saw no reduction.
Read more: Alzheimer’s Drug Approval Sparks a Firestorm
Limitations of Leqembi
While the approval of Leqembi is exciting news, the drug, like many other newly-approved medications, comes with side effects and certain drawbacks.
According to the press release, prescription information for Leqembi includes a warning for amyloid-related imaging abnormalities (ARIA). While ARIA typically has no symptoms, serious and life-threatening events related to Leqembi may occur because of it. These events include swelling in the brain or small patches of bleeding in or on the surface of the brain.
The most common side effects of Leqembi were infusion-related reactions, including flu-like symptoms, nausea, vomiting and changes in blood pressure. Headaches were also common to the drug.
Leqembi is also only meant to treat patients with mild cognitive impairment or those in the mild dementia stage of Alzheimer’s disease. Because this was the only population studied in Leqembi’s clinical trials, it cannot be prescribed to patients outside of this population. There is currently no data on the effectiveness of treating patients in earlier or later stages of the disease.