Scientists extract recent drug trials to tackle Alzheimer's earlier than ever before

Alzheimer's therapeutic trials have gotten bad press lately, but it is not all gloom and doom. As evident at the 5th Clinical Trials in Alzheimer's Disease (CTAD) conference, held 29-31 October in the Principality of Monaco, scientists keep extracting new data from recent drug trials to gear up for a round of new ones that aim to tackle Alzheimer's earlier than ever before. The Alzheimer Research Forum, an online resource specializing in Alzheimer's and related diseases, reported on event highlights.

At CTAD, the latest news on immunotherapies was most anticipated. Bapineuzumab and solanezumab are monoclonal antibodies that target Aβ, the principal component of the senile plaques found in brains of people with AD. Both fell short of their main goal in recent phase 3 trials. New data at CTAD confirms that solanezumab slowed mental decline up to 35 percent in the mildest group of patients. Bapineuzumab knocked down protein markers of brain cell death in the cerebrospinal fluid, but slightly hastened brain shrinkage. The hints of benefit for solanezumab offer hope for patients treated in early stages of the disease. Researchers continue to analyze both data sets to learn all they can about why these drugs failed in some aspects and succeeded in others. "These datasets are very large, and have more to tell us," said Paul Aisen of the University of California, San Diego.

Researchers also discussed the best ways to conduct trials targeting earlier stages of Alzheimer's, perhaps even before symptoms begin. The conference highlighted plans to refine the tools and designs necessary for this. Presenters pointed out the need to study younger age groups in clinical trials, because it is difficult to distinguish normal cognitive changes from those related to dementia in people over 85. Others suggested researchers administer cognitive tests more and avoid tests that people master with practice. Practice effects can make it difficult to separate improvements due to drugs over those that occur on placebo.

For data analysis, some scientists are adopting Bayesian statistics—the type that gained recent fame when it was used to correctly predict the U.S. Presidential election. This approach allows investigators to adapt trials as they are underway. Used successfully in cancer, adaptive methods could reveal the optimum dose of a drug by testing far fewer patients and in less time than is currently done, researchers say.

Alzforum's CTAD coverage highlights how drug regulatory agencies are evolving their stance on AD, trials of a new anti-inflammatory drug in people who are genetically at-risk of AD, the use of electroencephalography to monitor drug efficacy in trials, a sneak peak at European trials trying to prevent AD with lifestyle changes, and a look at the possible health economics of a goal researchers have been after, that is, a treatment that slows the course of AD, not just its symptoms.