The experimental drug lecanemab has shown to slow the progression of cognitive decline by 27% in patients with early-stage Alzheimer's disease, according to a study published this week in the New England Journal of Medicine.


"These findings show that lecanemab holds promise for people with early Alzheimer's disease, with significant slowing of decline and a reasonable safety profile," the study's principal investigator, Dr. Christopher H. Van Dyck.


Van Dyck is director of the Alzheimer's Disease Research Unit and professor of psychiatry, neurology, and neuroscience at Yale University School of Medicine.

The Van Dyck researchers said in the study that the drug lecanemab "reduced amyloid markers in early Alzheimer's disease and led to slightly less decline in cognitive function and function than placebo at 18 months – but was associated with adverse effects."

Pharmaceutical companies Eisai Co. Ltd. and Biogen Inc., developed the drug.




The drug is a monoclonal antibody — it disrupts the formation of amyloid plaque, which, according to experts, is considered the main culprit of Alzheimer's disease.


"Associated with less clinical decline"

The study included 1,795 participants who had early Alzheimer's disease.


According to the study, 898 of the participants received lecanemab while 897 received a placebo at 235 sites in North America, Asia and Europe from March 2019 to March 2021.

Participants received lecanemab intravenously every two weeks for 18 months.


"Analyses at 18 months showed dose- and time-dependent clearance of amyloid with lecanemab, and the drug was associated with less clinical decline than placebo in some measures," the researchers said in the published study.


The lecanemab-treated group reflected a slower progression of cognitive decline.


The investigators relied on an instrument that measures cognitive impairment. It's called the Clinical Dementia Rating-Sum of Boxes (CDR-SB) – it tracks participants' progress.


The mean baseline score was approximately 3.2 in both the lecanemab and placebo groups. A score of 0.5 to 6 is consistent with early Alzheimer's, according to the researchers.

After 18 months of treatment, the mean score in the lecanemab group increased by 1.21 points, compared with patients in the placebo group, who increased their score by 1.66 points.


The lecanemab-treated group reflected a slower progression of cognitive decline.


Some participants experienced adverse events, the researchers noted.

About 20% of patients taking lecanemab experienced brain swelling or bleeding in the brain, according to the study.


Lecanemab is expected to be approved by the FDA in early 2023.
Eisai said there were two deaths, although they were not believed to be linked to lecanemab.


Alzheimer's Discovery Drug Foundation (ADDF) officials said in a statement that lecanemab, which is expected to be approved by the FDA in early 2023, represents a positive step in the treatment of the disease and "welcome news for the millions of patients and families living with Alzheimer's."


Dr. Howard Fillit, co-founder and chief scientific officer at ADDF, also said in a statement: "But this is only the beginning of stopping Alzheimer's disease. We have a lot of room to go from the 27% slowdown [that] lecanemab offers to our goal of slowing cognitive decline by 100 %."


The ADDF statement says that amyloid-removing drugs are part of the solution to Alzheimer's disease.

However, further development of a new generation of drugs that can target specific pathologies that contribute to the disease is needed.



The Alzheimer's Association said it was encouraged by the global clinical trial of lecanemab.


"Unique drug combinations tailored to each patient's underlying pathology are the answer and our best hope to provide patients with long-term relief from this insidious and progressive disease," Fillit said in a released statement.


The Alzheimer's Association also issued a statement regarding the results of the third phase of the trial. |

On its website, the group said it was encouraged by the global clinical trial of lecanemab.


She said the study "confirms that this treatment can significantly alter the course of the disease in people in the earliest stages of Alzheimer's disease. The Alzheimer's Association is calling for expedited approval of lecanemab by the Food and Drug Administration."


The organization also noted in part: "These peer-reviewed published results show that lecanemab will give patients more time to engage in daily life and live independently. This could mean many more months of appreciation for their spouse, children and grandchildren."



"Statistically significant does not always mean practically significant, especially not in the setting of significant risks."


Dr. Marzena Gieniusz, medical program director of the Alzheimer's and Dementia Care (ADC) program at Northwell Health in Long Island, New York, commented on the findings.


Dr. Gieniusz, who was not involved in the study, said she was excited to see a statistically significant difference between the lecanemab and placebo groups in the study — but cautioned that more research on the drug is needed.


"Statistically significant does not always mean practically significant, especially not in the setting of significant risks that were noted in the study, as well as risks that were not yet apparent—including the potential for increased hospitalizations, unnecessary interventions, etc."

Gieniusz also told Fox News Digital, "While I'm happy to see the results so far, I want to learn more, including safety and efficacy, before I can meaningfully explore and weigh the practical risks, benefits and alternatives of this drug."

Van Dyck of the Alzheimer's Research Unit told Fox News Digital that more research is currently underway — and that researchers need participants.


"The next steps in our evaluation of this treatment will certainly be to move to asymptomatic, at-risk individuals even sooner." (A preclinical Alzheimer's trial has been ongoing since 2019, but is behind in enrollment.)


Van Dyck said he was "optimistic" that "the results will stimulate interest and enrollment and allow us to complete this important study."



Van Dyck also said he was "optimistic" that "the results will stimulate interest and enrollment and allow us to complete this important study. In addition to the important effects on early symptomatic AD, we would like to know if this can be substantially expanded to treat individuals before much damage is done and significant symptoms begin to appear."


According to the Alzheimer's Association, there is also a potential cost issue due to a Center for Medicare and Medicaid Services (CMS) policy that could block access to the treatment if approved by the FDA.