Test drug slows progression of protein tied to Alzheimer's

Researchers used advanced imaging technology to measure levels of amyloid in 28 patients taking bapineuzumab or a placebo, according to the report in the journal Lancet Neurology. The study was too small to demonstrate whether the drug improved mental function.

The results show investigators can track levels of amyloid as patients are treated for Alzheimer's disease, potentially identifying and speeding development of new drugs, said lead researcher Juha Rinne, a neurologist from the University of Turku in Finland. Currently, amyloid levels are measured at autopsy, the only way to definitively diagnose the disease that affects 30 million people worldwide, he said.

"This is the first time the effect of an Alzheimer's disease drug on the pathological changes in the brain was demonstrated in living patients," Rinne said in a telephone interview. "This treatment reduced the amyloid burden in patients with Alzheimer's disease as compared to those patients who were on placebo."

The study was funded by Ireland's Elan Corp., which sold its share of bapineuzumab to New Brunswick, New Jersey-based Johnson & Johnson last year, and Wyeth, which was bought by New York-based Pfizer in October. Elan holds 49.9 percent of the Johnson & Johnson company that acquired bapineuzumab, allowing it to share any profits and royalty payments the drug generates.