Cognitive effects seen as transient for Alzheimer’s drug atabecestat

Research should continue

Robert Vassar, PhD, of Northwestern University, Chicago, who was not a coauthor on the study, also expressed a desire for BACE inhibitor research to continue.

“It is my view that the cognitive worsening of atabecestat and the other BACE inhibitors was caused by overinhibition of the enzyme related to functions of certain BACE substrates in the brain,” Dr. Vassar commented. “A major question is whether a lower dose of BACE inhibitor – achieving about 30% inhibition – could be safe and lower amyloid-beta enough to delay onset in people still without symptoms. The good news of this study is that the atabecestat-related cognitive worsening is reversible, leaving open the possibility of low-dose prevention trials.”

Dr. Vassar noted that, with both doses of atabecestat, Dr. Sperling and colleagues did not see changes in neurofilament light or total tau, two biomarkers of neurodegeneration, but did report decreases in phosphorylated tau (p181 tau), a marker of disease progression, compared with placebo.

“This indicates that atabecestat did not cause neurodegeneration and in fact moved p181 tau in the beneficial direction for Alzheimer’s disease. Perhaps if it were not for the liver toxicity, the trial may have been completed and other Alzheimer’s disease biomarkers may have changed in the beneficial direction as well,” Dr. Vassar said.

Dr. Sperling and colleagues’ study was sponsored by Janssen, the manufacturer of atabecestat. Dr. Sperling disclosed receiving research funding from Janssen and other drug makers, while nearly all the study’s coauthors reported being directly employed by the sponsor or receiving industry funding. Dr. Aisen disclosed personal fees from several manufacturers and past fees from the sponsor. Dr. Vassar disclosed consulting and other financial relationships with biotechnology companies that did not include this study’s sponsor.