HARTFORD — One of the most popular working theories about Alzheimer’s disease is that it’s caused by plaques in the brain called amyloids, so many of the drugs being tested to fight Alzheimer’s have focused on removing those plaques. While other drugs have shown promise in fighting the development of these plaques, none have been proven to work on improving the symptoms of the disease, specifically by slowing patients’ cognitive decline.
BAN2401 is one of those drugs, and like many before, it was feared to not work on symptoms, until researchers got some surprising results from a phase II study. Those results have some people hopeful that it could be the future of fighting the disease, but there are still plenty of reasons to be skeptical.
Dr. Michael White, from the UConn School of Pharmacy, said BAN2401 did show an ability to fight those amyloids.
“This one actually has the ability to be able to reduce those plaques, not just slow its progression, but reduce the plaques that have already formed if you use it in early-stage disease,” he said.
The eye-popping part of the study revealed, at the highest dose tested, BAN2401 showed a 30 percent reduction in cognitive decline, a finding that would be remarkable if it can be replicated in other trials.
“If it turns out to be true, this could be the beginning of a new lead that could have this compound and then many others get in to the game,” Dr. White said.
There are some concerns about both the studyand the results.
BAN2401, as expected, showed an appropriate dose-response when fighting the plaques – roughly translated, dose-response means seeing proportionately more of an effect when you use more of a drug. That proportion wasn’t there when it came to improving actual symptoms.
While the highest-dose worked tremendously on symptoms, the lower doses didn’t work at all.
“In this trial, it was the highest dose that gave these impressive benefits, but no real dose response with any of the other doses, so that’s atypical,” White said.
There are several possibilities why.
White said it may be the case that the highest dose is actually the threshold level for effectiveness, meaning it could end up being the smallest dose at which BAN2401 is effective. It also could be the case that the popular theory about the mechanism behind Alzheimer’s is wrong – perhaps those amyloids aren’t the cause of the disease, but just a sign of the disease.
White also found a discrepancy in how the groups were selected for the study. He said that some Alzheimer’s patients have a particular gene variant that causes a much more rapid decline in symptoms, and those types of patients were under-represented in the group that received the largest dose and showed improvement.
“Was it because the drug was being more effective at that higher dose, or was it because they looked at a population that was going to have a slower decline anyway?” he asked.
BAN2401 is anticipated to graduate to phase III testing in the future, during which researchers can more closely study that highest dose