Even though newer monoclonal antibodies are available for Alzheimer’s disease, there are limits on the number of older adults who can receive them, a recent study published in Neurology finds.
Researchers studied newer monoclonal antibody medications on the market including lecanemab (Leqembi, Eisai) and aducanumab (Aduhelm, Biogen). The team looked at the clinical trial criteria to see which people were eligible for lecanemab. It drew conclusions based on 237 people from the Mayo Clinic Study of Aging (MCSA) database.
The people in the study all had mild cognitive impairment or mild dementia with increased amyloid in the brain. All of the people were between 50 and 90 years old. Of the people studied, only 112 — or 47% — were candidates for lecanemab. After applying other criteria, only 19 people, or 8%, would be eligible. When researchers modified that criteria to include people with mild cognitive impairment and didn’t account for other required memory and thinking tests, 17.4% were candidates.
Then the researchers looked at who could get aducanumab based on a trial, too. The scientists found that 44% of the patients in the MCSA database would meet the trial’s standards to get the medication. When the researchers added that trial’s exclusion criteria — stroke, high blood pressure and cardiovascular disease — just 5% would be eligible.
“There is hope that these new therapies for Alzheimer’s disease may slow progression of the disease for many people, although the fact remains that the drugs have only been studied in people with the earliest forms of the disease,” Maria Vassilaki, MD, senior author and assistant professor of epidemiology at Mayo Clinic, said.
“Our study estimates that only a small percentage of older people with early cognitive impairment because of AD may be eligible to be treated with monoclonal antibodies for amyloid-ß in the brain,” Vassilaki said.
People who were included in the lecanemab trial had specific scores on cognitive tests, and a body mass index (BMI) between 17 and 35. For aducanumab, people were between 50 and 85, and had specific scores on cognitive tests. People with multiple health factors were excluded. Older Black and Hispanic people were not adequately represented in the trials, Vassilaki said.
“Our study results show only a small percentage of people with early Alzheimer’s disease may be eligible to receive treatment, mostly because of chronic health conditions and brain scan abnormalities common in older adults,” Vassilaki said.
The US Food and Drug Administration gave accelerated approval for lecanemab in January 2023 and issued traditional approval in July 2023. The FDA approved aducanumab in 2021, but phase 4 studies still need to confirm its benefit — they’re expected in 2030.
