The newly FDA approved Alzheimer’s treatment Leqembi is ready at Abington Neurological Associates in Abington, PA., on Tuesday, November 7, 2023.
Hannah Yoon | The Washington Post | Getty Images
The breakthrough Alzheimer’s drug Leqembi slowed disease progression in patients over three years, demonstrating the necessity for them to remain on the treatment long run, in line with recent data released Tuesday by Japanese drugmaker Eisai.
The study results on Leqembi, which Eisai shares with Biogen, also found that a patient’s Alzheimer’s disease worsens after they stop treatment. Rates of opposed unwanted side effects related to Leqembi, including brain bleeding and swelling, dropped after six months of treatment, Dr. Lynn Kramer, Eisai’s chief clinical officer of deep human biology learning, told CNBC.
That decline is critical: Those unwanted side effects within the brain have raised concerns amongst some doctors and are the major reason a European drug regulator really helpful against approving Leqembi last week.
The study is the longest available efficacy and safety data up to now on Leqembi, which has had a bumpy rollout within the U.S. since winning regulatory approval last summer because of bottlenecks related to diagnostic test requirements and regular brain scans, amongst other issues. Eisai released 24-month data on Leqembi in November.
Eisai presented the findings on Tuesday on the Alzheimer’s Association International Conference in Philadelphia, the world’s largest meeting for dementia research. The outcomes are a primary glimpse at what Alzheimer’s patients’ future could appear like on therapies akin to Leqembi, which is currently taken twice a month through an infusion.
The drug is a monoclonal antibody that targets toxic plaques within the brain called amyloid, an indicator of Alzheimer’s, to slow the progression of the disease during its early stages. Leqembi also works by clearing protofibrils, the constructing blocks of amyloid plaque.
The info demonstrates the importance of early and sustained treatment for people living with the notoriously hard-to-treat brain disorder — even after a drug clears a patient’s amyloid plaque.
“Continuing treatment is essential in the event you would really like to take care of cognition and functionality longer,” Kramer said.
While Leqembi isn’t a cure, “in the event you start early enough, it might probably offer you years of profit,” he said.
Kramer added that Eisai believes patients can eventually switch to a maintenance dose of Leqembi after roughly 18 to 24 months of treatment, which might be a less frequent or more convenient method to take the drug over a protracted period.
Eisai and Biogen are looking for regulatory approval for a once-monthly infusion of Leqembi, with a call expected in January. The drugmakers also aim to bring to the market an injectable type of Leqembi that patients can take at home once every week.
“Those two things will change the paradigm, make it easier for the patient, make it easier for the entire medical system,” Kramer said in an interview.
Nearly 7 million Americans have the condition, the fifth-leading reason behind death for adults over 65, in line with the Alzheimer’s Association. By 2050, the variety of Alzheimer’s patients is projected to rise to almost 13 million within the U.S.
Long-term study details
The outcomes are based on prolonged research on certain participants in mid-stage and late-stage trials on Leqembi.
One phase three trial, called Clarity AD, examined three different groups of patients for 36 months.
One group of participants took Leqembi for the complete three years, while one other received a placebo for the primary 18 months before switching to Eisai’s drug for a similar length of time. Eisai observed a final group of patients outside of the trial who didn’t receive any treatment over three years.
Tek Image/science Photo Library | Science Photo Library | Getty Images
Patients who began Leqembi early continued to learn from the drug over three years, showing a slower rate of cognitive decline in comparison with the opposite two groups, in line with an Eisai presentation.
The difference in cognitive decline between the “early start” Leqembi group and patients who didn’t receive anything throughout the study period grew larger between 18 and 36 months, in line with Kramer.
Leqembi “interrupts the natural progression of the disease, and it has an effect an increasing number of,” he said, adding that “the sooner you catch it, the higher.”
Patients who began on a placebo saw a slower rate of cognitive decline after switching to Leqembi on the 18-month mark. But their Alzheimer’s disease was still worse than the group that began Leqembi earlier through the 36 months.
A sub-study of the trial partly examined patients with no or very low levels of one other protein that builds up within the brain called tau, which is taken into account a marker of Alzheimer’s severity. Individuals with low levels of that protein are at the sooner stages of the disease.
After three years on Leqembi, 59% of individuals with no or very low tau levels didn’t see their Alzheimer’s progress in any respect, in line with the presentation. Somewhat over half of that patient population actually saw their condition improve.
Meanwhile, one phase two trial, called Study 201, examined patients who temporarily stopped treatment with Leqembi.
For 18 months, one group of participants took Leqembi and one other received a placebo. The groups then took nothing during a spot period of two years on average before all patients began treatment with Leqembi for an additional 18 months.
Leqembi’s positive effect on a patient’s disease was maintained even after they stopped treatment, in line with the presentation.
However the rate of cognitive decline in patients who stopped Leqembi reverted to the speed of people that had taken a placebo throughout the gap period. That shows that even when amyloid plaque is removed, the disease continues to progress when a patient stops Leqembi, Eisai said in a release.
“The concept is, in the event you stop, you worsen,” Kramer said.
