Alzheimer’s Drug Fails in Clinical Trial

Alzheimers disease drug did not improve function for people who had a genetic risk factor

(RxWiki News) The APoE4 gene increases the risk of Alzheimer’s disease (AD) and is thought to influence how quickly AD progresses, but a new drug failed to help people with this gene.

Pfizer recently reported that its new drug failed to work in phase 3 clinical trials. The drug did not improve cognition or functioning in people with mild-to-moderate AD who had the APoE4 gene. More trials are planned in people without the APoE4 gene.

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Pfizer is delaying release of the full details of the failed clinical trial, which are expected to be released at a scientific meeting in the near future.

The drug, called bapineuzumab, was developed as part of an alliance between Janssen Pharmaceuticals and Pfizer. It targets beta amyloid, a protein that is known to build-up in the brains of people with AD.

Phase 3 trials, the final phase of FDA approval trials, typically uses a large numbers of people, 1,000 to 3,000 people. In these types of trials, drugs are given to people with the disorder and they are monitored closely to see if the drug is working and if the drug is safe.

In the first completed phase 3 trial, patients who had APoE4 were given either bapineuzumab or placebo.

Those taking the new drug did not show any improvement on cognitive tests or measures of functioning compared to those taking placebo.

Additionally, people in this trial taking bapineuzumab had some serious side effects compared to placebo patients. Dehydration and a condition where fluid leaks out of the blood vessels in the brain occurred in about 1 percent of patients taking bapineuzumab.

Pfizer reported in their recent press release that three other phase 3 trials are planned, some in people who are not carriers of the APoE4 gene. 

People with AD and the APoE4 gene build-up beta amyloid plaques more quickly and often have more plaques than people with AD not carrying the APoE4 gene.  This may be why this trial targeted people who carry the gene.

However, Pfizer expects the drug to show different results in people who do not have APoE4.

In the recent press release, Steven J. Romano, MD, senior vice president, Medicines Development Group, Global Primary Care Business Unit, Pfizer Inc., said, “[A] more complete understanding of bapineuzumab and its potential utility in mild-to-moderate Alzheimer’s disease will be gained following the availability of additional data, including data from the soon-to-be available non-carrier [study].”

The Pfizer press release was published on the Pfizer website on July 23.

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Review Date: 
July 25, 2012