Treating Alzheimer's with Lecanemab: A Clinical Guide
A new drug called lecanemab (Leqembi®) has been approved for the treatment of Alzheimer's disease in the United States. The drug is specifically intended to be used in patients with early Alzheimer's disease, which means they have mild cognitive impairment due to Alzheimer's disease or mild Alzheimer's dementia, and confirmed brain amyloid pathology.
Dr. Aisen recently contributed to the paper “Lecanemab: Appropriate Use Recommendations”, in the Journal of Prevention of Alzheimer's Disease. This paper discusses the appropriate use recommendations (AURs) for lecanemab. These AURs are intended to help guide clinicians in administering the drug safely and effectively in real-world clinical practice.
What is Lecanemab?
Lecanemab is a monoclonal antibody therapy, which means it works by targeting and removing a specific type of protein, called amyloid, from the brain. This protein is believed to play a role in the development and progression of Alzheimer's disease.
While lecanemab has been approved for use, it's important to remember that it is not a cure for Alzheimer's disease. Instead, it's a tool that can help manage the symptoms and slow down the progression of the disease.
Eligible Patients for Lecanemab
In order to qualify for Lecanemab, a positive amyloid biomarker must be present. This could either be elevated amyloid on PET (positron emission tomography) imaging or elevated phosphorylated tau and low Aβ42 level in the CSF (cerebrospinal fluid). These biomarkers help to establish that abnormal amyloid, which is the target of anti-amyloid monoclonal antibodies like lecanemab, is present in the patient's brain.
However, not everyone with a positive amyloid biomarker is a candidate for lecanemab treatment. The phase 2 and phase 3 studies for lecanemab excluded patients who were outside a specific age range of 50-90 years old. Additionally, participants with other unstable medical conditions, stroke or transient ischemic attacks, bleeding disorders, or seizures in the previous 12 months were also excluded from the phase 3 trial. Those with depression who scored >8 on the Geriatric Depression Scale or had a body mass index (BMI) greater than 35 or less than 17 were also excluded from both the phase 2 and 3 studies.
Lecanemab Treatment
Lecanemab is administered through an intravenous line every other week and dosing is weight-adjusted. The infusion takes approximately one hour, and patients are observed for three hours after the first infusion to monitor for infusion reactions. MRIs are recommended after specific infusions and for APOE4 carriers to detect and manage ARIA symptoms. Heightened vigilance is needed for APOE4 carriers and homozygotes, and after 12 months of treatment, MRIs should be guided by patient symptoms and prior MRI findings.
Side Effects and Risks
While the safety and efficacy of lecanemab have been demonstrated in clinical trials, there are some potential side effects associated with lecanemab, including amyloid-related imaging abnormalities (ARIA) and infusion reactions. The AURs provide monitoring guidelines for these events to help clinicians manage them effectively.
Lecanemab offers hope to those with MCI
While this is an exciting step forward in Alzheimer’s disease research, lecanemab is not a cure for Alzheimer's disease, and like any medication, it comes with potential risks and benefits. Clinicians and patients must work together to understand the potential benefits and risks associated with this treatment and develop a plan that works best for each patient's individual needs.
Ultimately, the approval of lecanemab offers new hope for the treatment of Alzheimer's disease and while there is still much to be learned about the drug and how it can be used safely and effectively, the AURs provide guidance for clinicians to help them use the drug in a way that maximizes its benefits while minimizing its risks.