PHILADELPHIA — Twenty months ago, the small biotech company Anavex announced that an experimental pill for Alzheimer’s disease helped slow cognitive decline on three common tests used to study the progress of dementia. But a new analysis suggests the results of that study are mixed.
At the Alzheimer’s Association International Conference on Sunday, data from the Phase 2b/3 study showed that the drug, called blarcamesine, only passed one of its two primary endpoints, and with more modest benefits than the company originally suggested.
The company said that medium and high doses of the drug, taken daily for 48 weeks, both produced a statistically significant 2-point difference on a 70-point cognition scale called ADAS-Cog13 — one of the study’s primary endpoints. But the drug was not better than placebo on the study’s other primary endpoint, a scale called ADCS-ADL.
And although Anavex said it enrolled 508 patients in the study, 46 of these patients were missing in the baseline results, and only about 310 patients were included in the final analysis. Scientists not involved in the study characterized the apparent 40% dropout rate as unusually high.
Dizziness, confusion, fatigue, anxiety, lethargy and balance issues were among the side effects more common in people taking the drug.
Marwan SabbaghMarwan Sabbagh, a neurologist at the Barrow Neurological Institute and chair of the New York company’s scientific advisory board, presented the results. He said the drug activates autophagy, the process that cells use to clean up debris, and that its mechanism could be complementary to the recently approved amyloid-targeting antibodies.
When Endpoints News asked Sabbagh about the discrepancy between the new data and the earlier results presented at another Alzheimer’s conference in late 2022, Sabbagh declined to comment and diverted all questions to Anavex. But the company’s scientific leaders couldn’t give a clear answer either.
The company’s head of research and development, Juan Carlos Lopez-Talavera, said he wasn’t able to explain the differences because he only joined the company in recent months. Kun Jin, who joined Anavex as head of biostatistics in March 2023 after working as a neurology statistician at the FDA, said more details would be published in a peer-reviewed journal in the future — something the company has promised for nearly two years.
In an email, a company spokesperson said that the discrepancy was because the new analysis looks at the medium and high doses separately, while the prior analysis combined them. The new analysis will be used for submission to the European Medicines Agency in the fourth quarter.
Anavex came under scrutiny after those original results were released, in part because it altered its primary endpoints.
The company is testing its drug in other neurological diseases too, and has tried to spin negative results from a trial in Rett syndrome. Multiple class action lawsuits have been filed against the company.