A study showing an experimental Alzheimer’s drug slowed cognitive decline was eagerly received by patients and their families awaiting new treatments to fight the progressive disease that has no known cure, but two deaths among trial patients have raised questions about its safety.
A second clinical trial patient, a 65-year-old woman, recently died from a brain hemorrhage while receiving treatment as part of a study for Eisai and Biogen’s Alzheimer’s drug, lecanemab, tampering some of the enthusiasm surrounding the drug, according to a case report obtained by Science.
Lecanemab is intended to treat the disease by targeting a type of plaque in the brain made up of the protein beta-amyloid, which accumulates in the brains of Alzheimer’s patients and is thought to cause memory and cognitive problems.
The woman who received lecanemab as part of the trial suffered a stroke and was given treatment to clear her blood clots, but died several days later.
Another patient that was a part of the study died in June after experiencing brain bleeding. One of the study’s investigators concluded that the death was related to the drug, according to documents obtained by STAT.
Eisai told the Washington Examiner in a statement that it couldn’t provide information on specific patients, but said available safety data suggests that the drug does not increase one’s risk of death.
“It can be difficult to determine what contributed to the death in any given patient, in particular when they are elderly, have multiple medical problems, and may have recently received a concomitant treatment or intervention for an acute condition,” the company said. “All the available safety information indicates that lecanemab therapy is not associated with an increased risk of death overall or from any specific cause.”
Renewed worries over the drug’s safety come as Eisai and Biogen are set to present the full results from its Phase 3 study at an Alzheimer’s conference on Tuesday, which may provide more insight on the matter.
The pharmaceutical companies reported back in September that lecanemab reduced cognitive and functional decline by 27% in the test group, compared to those on a placebo treatment, over 18 months in a Phase 3 study of nearly 1,800 participants in the early stages of Alzheimer’s. The drug has been granted priority review by the Food and Drug Administration, meaning the agency is expected to decide whether it should be authorized within six months by Jan. 6, 2023, instead of the typical ten months.
The results were met with excitement and some skepticism among those in the Alzheimer’s community, as previous anti-amyloid antibody treatments have had mixed results.
“These are the most encouraging results in clinical trials treating the underlying causes of Alzheimer’s to date,” the Alzheimer’s Association said in a statement back in September. “These results indicate lecanemab may give people more time at or near their full abilities to participate in daily life.”
Earlier this month, results from a trial testing another Alzheimer’s drug candidate from Roche, gantenerumab, showed that it did not have any substantive cognitive and functional changes among patients in the early stages of the disease.
Biogen’s Aduhelm, the first new therapy approved for Alzheimer’s in nearly two decades, has also faced challenges on the market since it was authorized last year amid concerns over its effectiveness.