Eisai Responds to Claims Linking Patient Death to Lecanemab (Updated)

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An investigator in the Phase III trial for Biogen and Eisai’s experimental Alzheimer's drug lecanemab is attributing a patient’s death to the treatment. 

The unnamed study investigator said the death occurred in June following bleeding in the brain, and determined it was related to lecanemab, according to STAT News, which broke the story Friday. 

Eisai, for its part, pointed to other possible factors such as multiple falls, a heart attack and mini stroke-like events.  

Libby Holman, senior director of product communications at Eisai U.S. did not confirm nor deny the investigator’s claim, in a written statement to BioSpace.

“Our studies are assessed by Eisai as well as independent data safety monitoring boards (DSMBs), comprised of external experts,” Holman said. “Eisai and the DSMBs review the safety data on an ongoing basis ... All the available safety information indicates that lecanemab therapy is not associated with an increased risk of death overall or from any specific cause." 

Holman confirmed the allegation of the patient’s death was related to ARIA, adding that “the independent DSMB completed a review of all ARIA-related safety data.”

BioSpace reached out to Biogen for comment and was forwarded to the Eisai communications team. 

Amyloid-related imaging abnormalities (ARIA) has been the primary serious adverse event connected with Biogen’s approved Alzheimer’s treatment, Aduhelm. In November, Biogen revealed it was investigating the death of a 75-year-old woman who died of ARIA while receiving Aduhelm.

ARIA, which includes cerebral edema, is associated with headache, confusion, nausea and gait disturbances. It is a known adverse event associated with anti-amyloid antibodies, a class that also includes lecanemab. Aduhelm’s label contains a warning to physicians to monitor for ARIA-E but not to necessarily remove patients from the drug.

Lecanemab sparked a new wave of optimism in the Alzheimer’s R&D space when Biogen and Eisai announced the drug had slowed disease progression in a Phase III trial. The new reports of the patient’s death have tempered this some, as Biogen’s shares took a hit in pre-market trading Friday.

In results the partners called “highly statistically significant” data from the CLARITY AD study showed lecanemab reduced the clinical decline of patients with mild to moderate Alzheimer’s by 27% compared to placebo after 18 months. This was based on the Clinical Dementia Rating-Sum of Boxes (CDR-SB) assessment. The experimental treatment slowed the loss of memory and thinking skills, according to the companies.

The rate of ARIA-H (ARIA cerebral microhemorrhages, cerebral macrohemorrhages, and superficial siderosis) was 17% in the lecanemab group compared to 8.7% in the placebo group. The ARIA-E rate was 12.5% in the lecanemab group and 1.7% in the placebo group.

"In the Phase II study, the rate of death in patients receiving lecanemab was no more frequent than in patients receiving placebo," Holman said in the statement. 

“Eisai promptly communicates important safety information to sites, investigators and subjects through a variety of appropriate mechanisms including investigator communications, Independent Review Board communications and Informed Consent Form revisions,” she added.