Lecanemab, a new Alzheimer’s drug, performed highly in its recent phase 3 trial, but questions linger about possible health threats for older adults.
On Nov. 29, pharmaceutical company Eisai, who created lecanemab in collaboration with Biogen, announced the results of the phase three trial at the Clinical Trials on Alzheimer’s Disease Congress, concluding this week in San Francisco.
The trial results showed that lecanemab was able to slow participants’ cognitive decline by 27% in 18 months and fight amyloid plaques, which form when naturally occurring proteins clump together between neurons and disrupt their normal function.
The trial results showed that lecanemab was able to slow participants’ cognitive decline by 27%.
“The drug showed a slowing of decline of cognitive and functional abilities, and it had very tolerable potential side effects,” said Douglas Scharre, MD, a site principal investigator at The Ohio State University who worked on the lecanemab trials. “It is a disease-modifying therapy.”
However, some participants did not respond well to the drug, and in fact two deaths resulted from the study—including a man in his late 80s who died from a brain hemorrhage while taking lecanemab, as reported by STAT. The complication is reported to have been caused by a reaction between the Alzheimer’s drug and Eliquis, a blood thinner the participant was taking. However, Eisai said the Alzheimer’s drug cannot be directly linked to this death.
Another death occurred just before Eisai released the data from the phase three trial, as Science reported on Nov. 27. A 65-year-old woman in the study died from a brain hemorrhage while taking lecanemab. She suffered a stroke following the antibody infusion and was given a tissue plasminogen activator to treat it, which caused the hemorrhage.
“All the available safety information indicates that lecanemab therapy is not associated with an increased risk of death overall or from any specific cause,” Eisai told Science.
Aside from the deaths, Biogen reports some participants experienced other side effects, including infusion reactions, microhemorrhages, headaches and falls throughout the trials.
Still, some experts say the benefits of the drug outweigh the dangers.
“It is safe, as there are safety assessments in place to identify issues early,” Scharre said. “There was one more death in the placebo arm than in the lecanemab arm of the study.”
Howard Fillit, MD, co-founder and chief science officer for the Alzheimer’s Drug Discovery Foundation, echoed Scharre’s confidence in lecanemab:
“We are closer than ever to developing a new generation of drugs that targets the many causes of this devastating disease,” Fillit said in a press release. “While several media reports have called attention to safety concerns, the data shows lecanemab was generally well-tolerated. It will require close monitoring, particularly in patients at higher risk, such as those taking [blood thinners], but overall, I see these results as starting us down a promising path.”
On Jan. 6, 2023, the FDA is expected to decide whether or not to grant lecanemab priority approval, which speeds up the process of getting a new drug on the market.