Lecanemab's Real-World Use Reveals Scarce Side Effects in Alzheimer's Patients
In the realm of Alzheimer's disease, where a cure remains elusive, new treatments like lecanemab are making headway. This medication, marketed as Leqembi, earned FDA approval in 2023 to address the relentless advance of this type of dementia.
Like any drug, lecanemab comes with its share of potential side effects. Among these are headaches, dizziness, muscle aches, and blurred vision, but perhaps the most concerning is amyloid-related imaging abnormalities (ARIA). ARIA arises when there's swelling or bleeding in the brain, a potentially serious condition that's possible with lecanemab treatment.
In late 2022, a study published the outcomes from the Clarity AD phase 3 clinical trial. It aimed to evaluate the safety and efficiency of lecanemab for individuals with early-stage Alzheimer's disease. There, researchers reported low instances of ARIA; only 0.8% of participants experienced ARIA-E (edema/effusion), and 0.7% showed signs of ARIA-H (hemorrhage/hemosiderin deposition).
A fresh study confirmed those Clarity AD findings. Published recently, it reported that significant adverse events—such as ARIA—were uncommon and manageable in the real-world setting where lecanemab was used for those in the earliest stages of Alzheimer's disease.
What Exactly is Lecanemab?
For this study, scientists enrolled 234 individuals with early Alzheimer's symptoms, with an average age of 74. These participants were treated with lecanemab at the outpatient specialty memory clinic, Washington University Memory Diagnostic Center.
In her explanation to Medical News Today, Barbara Joy Snider, MD, PhD, a professor of neurology at WashU Medicine and affiliated with the Knight Alzheimer's Disease Research Center, described lecanemab as an antibody. An essential component of the immune system, antibodies like lecanemab are designed to target specific points and are manufactured before being administered to patients. They're used across a range of conditions.
The Dance between Lecanemab and Amyloid Proteins
Lecanemab was created to recognize particular types of amyloid proteins. These proteins can become misshapen in the body, interfering with brain activity and forming clumps called plaques. In Alzheimer's disease, such amyloid misfolding can be one of the initial steps leading to memory loss and dementia.
According to Snider, participants who received lecanemab for 18 months had about a 25-30% slower decline in their memory and thinking compared to those who didn't receive the medication. This decline, however, wasn't reversed or completely halted by lecanemab. Instead, it was significantly slowed down. Moreover, imaging studies showed that the drug reduced and in some instances cleared the amyloid plaques in the brain.
In the concluded study, researchers observed that 1.8% of participants in the earliest stage of Alzheimer's disease developed ARIA symptoms, compared to 27% of those with mild Alzheimer's disease. Encouragingly, the effects of ARIA in most patients disappeared within a few months, and no fatalities occurred.
The emergence of ARIA in just 1.8% of patients at the earliest stage of Alzheimer's disease further underscores the significance of early diagnosis. Those with very mild symptoms may benefit more from therapies like lecanemab (offering a 40-50% slowing of decline instead of the 25-30% encountered in individuals with mild symptoms).
More Research Needed to Identify ARIA Risk
John Dickson, MD, PhD, a neurologist at Massachusetts General Hospital, weighed in on the study's findings. He noted that, in his observation, ARIA incidents in patients treated with lecanemab have been manageable in specialist care centers. The risk of ARIA is often the deciding factor in eligible patients' decisions about whether to pursue treatment with anti-amyloid therapy or not.
Since this study involved a relatively small patient cohort, additional research is essential to back up the findings with larger patient samples and extended observation periods. As for future research, scientists should focus on identifying patients who are more likely to experience ARIA. By doing so, clinicians could provide patients with more personalized recommendations based on their individual risk profiles.
The Balancing Act: Benefits vs Side Effects
Experts emphasize that while the approval of lecanemab offers hope for Alzheimer's patients, the potential for serious side effects necessitates careful consideration. Effective patient selection, monitoring, and open dialogue about benefits and risks are vital. By identifying those most likely to benefit from lecanemab and least likely to experience severe side effects, physicians can offer the best possible treatment options for their patients.
- Lecanemab, an antibody designed to target specific types of amyloid proteins, is a new treatment for Alzheimer's disease that was approved by the FDA in 2023 to address dementia.
- Despite its potential benefits, lecanemab comes with various side effects, including headaches, dizziness, muscle aches, blurred vision, and amyloid-related imaging abnormalities (ARIA).
- Studies have shown that significant adverse events, such as ARIA, are uncommon and manageable in the real-world setting, particularly for seniors in the earliest stages of Alzheimer's disease.
- Researchers believe that early diagnosis and treatment with therapies like lecanemab could result in a 40-50% slowing of decline in symptoms, compared to the 25-30% seen in individuals with mild symptoms.
- While the emergence of ARIA remains a concern, further research is needed to identify patients who are more likely to experience this condition and provide personalized recommendations based on individual risk profiles. This balancing act between benefits and side effects will be essential to optimizing treatment outcomes for Alzheimer's patients.
