Members of a US Food and Drug Administration (FDA) advisory committee have unanimously concluded that a postmarketing study confirms the benefit of the Alzheimer’s drug lecanemab (Leqembi; Eisai Inc), paving the way for traditional approval.
“Overall, the study demonstrated clearly that this is an effective treatment,” said acting chair Robert C. Alexander, MD, chief scientific officer, Alzheimer’s Prevention Initiative, Banner Alzheimer’s Institute, and research professor, Department of Psychiatry, University of Arizona College of Medicine, Phoenix, during the meeting.
An intravenous infusion targeting amyloid beta, lecanemab received accelerated FDA approved earlier this year for the treatment of early Alzheimer’s disease (AD). The company was required to complete a confirmatory study to verify and describe the product’s clinical benefit.
The Peripheral and Central Nervous System Drugs Advisory Committee met to discuss this phase 3 study (CLARITY-AD). The multicenter, double-blind study included 1795 patients (mean age, 71 years) who had mild cognitive impairment due to AD or mild AD dementia.
Study participants had a broad range of comorbidities, and many were concomitantly receiving other medications. Black people were underrepresented in the study at just 3% of the total cohort.
Patients were randomly assigned to receive placebo or lecanemab 10 mg/kg biweekly. In addition to a placebo-controlled period and safety follow-up, the study has an ongoing extension phase of up to 4 years.
The study met its primary endpoint, showing a highly statistically significant 27% less decline on the Clinical Dementia Rating-Sum of Boxes at 18 months (difference in adjusted mean: -0.45; 95% CI, -0.67 to -0.23; P = .00005).
This was supported by a significant 26% difference on the AD Assessment Scale–Cognitive Subscale with 14 tasks (ADAS-Cog 14).
The drug also affected function, with a 37% decrease compared to placebo on the AD Cooperative Study–Activities of Daily Living Scale for Mild Cognitive Impairment.
Committee members heard that the results signal delays in disease progression by about 5 months, giving patients more time to live independently and participate in hobbies and interests.
Patients who received the active drug also experienced quality-of-life benefits. Compared to patients who received placebo, those who took lecanemab had 49% less decline as measured with the European Quality of Life–5 Dimensions scale and 56% less decline as measured by the Quality of Life in AD scale, and caregivers reported less burden.
Lecanemab also affected biomarkers of amyloid, tau, and neurodegeneration, providing a biological basis for the treatment effects consistent with slowing of disease progression.
All six committee members agreed by vote that the study provides evidence of clinical benefit. They variously descried the study and results as “robust,” “compelling,” “well conducted,” “clear and consistent,” and “clinically meaningful.”
In the active treatment group, there was a higher incidence of amyloid-related imaging abnormalities (ARIAs), which can be serious and life-threatening but are usually asymptomatic. In this study, most ARIAs had resolved by 3 months.
Deaths occurred in 0.8% of the placebo and 0.7% of the treatment group. Dean Follmann, PhD, assistant director for biostatistics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, noted that the numbers of deaths and serious adverse events were “quite similar” in the two groups.
“And for serious ARIA, there was an imbalance favoring placebo, but overall, these were pretty rare,” he said.
Committee members discussed the risk/benefit profile for three subgroups of patients ― those with apolipoprotein E 4 (ApoeE-4) allele, patients taking an anticoagulant, and those with cerebral amyloid angiopathy (CAA).
In the ApoeE-4 group, the study’s primary endpoint did not favor the drug, but secondary endpoints did.
“I think the general feeling [for ApoeE-4 status] is that the risk/benefit still remains favorable, especially when looking across multiple endpoints,” said Alexander.
However, some members supported recommending genetic testing before initiating the drug.
The views were more diverse for the use of lecanemab in the presence of an anticoagulant, which may increase the risk for cerebral hemorrhage. Some committee members strongly recommended that these patients not receive lecanemab, while others highlighted the need for more information, owing to uncertainties about the risks.
With respect to CAA, most members supported the idea of considering use of the drug in the presence of this condition, but only after discussing the risks with patients and their families and in the presence of a robust reporting system.
An Alzheimer’s Association representative was in attendance during the public hearing portion of the meeting to express support for traditional approval of lecanemab for people with early AD.
The Association strongly favors full Medicare coverage for FDA-approved AD treatments. The Centers for Medicare & Medicaid Services (CMS) has determined that AD treatments receiving traditional FDA approval will be covered if clinicians register and enter data in a registry.
“While this is an important signal that CMS wants to improve access to FDA-approved treatments, registry as a condition of coverage is an unnecessary and potentially harmful barrier,” said the Alzheimer’s Association in a press release following the meeting.