Alzheimer's drug shows positive results in mild cases

• Results help researchers target a cause of the disease
• Next research will start drugs in patients who are pre-symptomatic
• Alzheimer's is the only disease among top 10 without a treatment

BOSTON — Researchers announced Monday that an experimental Alzheimer's therapy has shown it slows the progression of the disease in people with mild cases, bringing them a "step closer" to finding the first treatment and to understanding a cause of the complex disease.

Academic researchers discussed the results of large studies on solanezumab, funded by Eli Lilly, and bapineuzumab, funded by Janssen Alzheimer Immunotherapy and Pfizer, at the American Neurological Association's 2012 Annual Meeting. The aim of both therapies is to remove beta amyloid from the brain. The sticky protein has long been thought to be a toxic substance that affects functioning of the brain — similar to how high cholesterol levels damage the heart.

The findings on solanezumab were presented today by the Alzheimer's Disease Cooperative Study.

"Alzheimer's research is very complicated," said Rachelle S. Doody, chair in Alzheimer's disease research at the Baylor College of Medicine in Houston and member of the ADCS. "But our committee is encouraged by the results of the solanezumab studies. They support amyloid as a target for future Alzheimer's research."

Until now, researchers have only been able to theorize about the mechanisms of the disease. Research is also being conducted on other possible causes, including inflammation and tau, tangles of proteins thought to disrupt communication among neurons' pathways.

"We are encouraged by the results,'' said Maria Carrillo, vice president of medical and scientific relations for the Alzheimer's Association, an advocacy group. "It's not the home run we wanted to see but this is the first time we've seen a slowing of cognitive decline."

A total of 2,052 patients were randomized to receive either solanezumab or a placebo every four weeks for 18 months. The data in the solanezumab studies showed positive results among subgroups ofpatients with mild Alzheimer's, reporting improvements of 34% in cognitive skills (memory and orientation in space and time). In daily functions (household chores), the improvement was 17%, considered not statistically significant. Lilly officials are discussing how to proceed with federal regulators. More detailed results will be reported at the end of this month, Lilly officials said. The FDA requires improvements be made in both cognitive and daily functioning skills in order to approve a drug for treatment.

In August, findings on bapineuzumab failed to show significant improvement in cognitive skills or daily functioning. Manufacturers have halted development of the drug while cademic researchers continue to examine the data.

On Monday, Reisa Sperling, director of the Center for Alzheimer's Research and Treatment at Brigham and Women's Hospital in Boston, reported positive results in bapineuzumab's ability to reduce beta amyloid, compared to those on the placebo.

"Hopefully, these new (biomarker) results from the bapineuzumab studies together with the clinical results from the solanezumab studies may provide a potential path forward for Alzheimer's research,'' said Sperling.

Treating patients with moderate disease symptoms might ultimately be ineffective in slowing the disease, researchers are finding. An August study in the New England Journal of Medicine reported that changes in the brain from Alzheimer's appear to begin as early as 25 years before symptoms appear. Upcoming research is designed to be conducted on people who are pre-symptomatic.

"The jury is still out,'' said Carrillo. "It could be that daily functioning would have improved at a higher percentage if given more time to improve. It makes sense the cognitive change has to come first. "