Eisai’s investigational Alzheimer's drug lecanemab appeared to erase amyloid plaques in 4/5 of trial participants and slow cognitive decline for people with early-stage Alzheimer’s disease in Phase 2B trials. Optimistic about the drug's efficacy, the company has initiated its submission for accelerated FDA approval.
The biotechnology company Eisai Co., Ltd. announced a rolling submission for accelerated approval from the Food and Drug Administration for their anti-amyloid Alzheimer’s treatment, lecanemab. In a Phase 2B trial, lecanemab reduced amyloid plaques while also slowing cognitive decline in early-stage Alzheimer’s disease (AD) — showing potential to modify the course of the disease.
In June 2021, lecanemab received a Breakthrough Therapy designation from the FDA, which exists to help expedite the development and review for treatments to severe, life-threatening conditions. In a next step, this accelerated approval track would speed up the review of lecanemab, with the ultimate goal of getting effective, approved Alzheimer’s treatments into patients’ hands sooner.
“For many years, Eisai has endeavored to understand the anxieties of people living with AD and has been conducting research and development of novel therapies,” Haruo Naito, chief executive officer at Eisai Co., Ltd. said in a press statement. “As part of our human health care mission, we are committed to bringing new medicines to people living with AD and their families as early as possible.”
The antibody-based treatment lecanemab works similarly to the recently approved anti-amyloid drug Aduhelm (aducanumab). In Alzheimer’s, beta-amyloid proteins accumulate as plaques in the brain, causing progressive cell death and inflammation. Drug developers believe that if these amyloid plaques are responsible for Alzheimer’s progression and symptoms, removing them could improve cognitive outcomes.
For Eisai’s Phase 2B study, 856 people diagnosed with mild cognitive impairment because of Alzheimer’s, as well as those with early Alzheimer’s who were confirmed to have amyloid plaques in their brain, were recruited.
After 18 months, lecanemab reduced amyloid pathology in the brain with 4/5 of participants becoming “amyloid negative” — that means when an expert looks at the results of brain scans, amyloid pathology is no longer visible.
In addition, the clearance of amyloid correlated with a slower cognitive decline across different cognitive scales including the Alzheimer’s Disease Composite Score, the Clinical Dementia Rating-Sum-of-Boxes, and Alzheimer Disease Assessment Scale-Cognitive Subscale. Results were published a peer-reviewed scientific journal.
About one in 10 people experienced the side effect of mild brain inflammation — amyloid-related imaging abnormalities-edema/effusion (ARIA-E) — which was also observed in Aduhelm’s drug trials.
The Phase 3 trial, called Clarity AD, has already enrolled 1,795 people with AD. Once the results of this study are complete and analyzed, lecanemab may receive full approval from the FDA.
Though mired in controversy, the approval of Aduhelm opened the door for testing and improving anti-amyloid-based treatments for Alzheimer’s. Lecanemab’s trials so far seem to bolster evidence that amyloid plaques are connected to Alzheimer’s-related cognitive decline.
“Based on the efficacy and safety results of the Phase 2B study and preliminary results from the open-label extension study, I am optimistic about the potential lecanemab may have as a treatment choice for patients with early Alzheimer’s to ameliorate the otherwise inevitable decline they face,” said Dr. Jeffrey Cummings, lecanemab manuscript author, and director at the Chambers-Grundy Center for Transformative Neuroscience, University of Nevada Las Vegas.
If the FDA greenlights lecanemab, it will become the second disease-modifying drug approved for treating Alzheimer’s in the U.S.