Two experimental drugs do not appear to slow memory loss or mental decline in patients in the early stages of a rare, inherited form of Alzheimer's disease, according to initial results from a clinical trial.
The international phase 2 and 3 clinical trial separately evaluated the two drugs — solanezumab (Eli Lilly and Co.), and gantenerumab (Roche and its U.S. affiliate, Genentech) — in nearly 200 people with dominantly inherited Alzheimer's disease, also called autosomal dominant Alzheimer's disease.
People with this form of Alzheimer's suffer declines in memory and thinking skills starting in their 50s, 40s or even 30s.
The patients were followed for up to seven years, with an average of five years. Initial analysis suggests that neither drug achieved the primary outcome of the study, which was a slowing of mental decline as measured by thinking and memory tests.
"Although the drugs we evaluated were not successful, the trial will move us forward in understanding Alzheimer's," study director Dr. Randall Bateman, a professor of neurology at Washington University in St. Louis, said in a university news release.
The study can help guide future research into the disease, including the more common form that typically strikes after age 65, according to Bateman.
Alzheimer's-related brain changes that occur as the disease progresses are much the same in patients with the inherited, younger-onset and the late-onset forms of the disease, he explained.
Both forms have "silent" phases that begin up to two decades before symptoms appear. The disease process starts with the accumulation of plaques of the protein amyloid beta in the brain. The two drugs in the study were designed to target the protein.
A more detailed analysis of the trial's data will be presented for the first time April 2-5 at the Advances in Alzheimer's and Parkinson's Therapies annual meeting, in Vienna, Austria. Research presented at meetings is considered preliminary until published in a peer-reviewed journal.