The manufacturers of bapineuzumab, Wyeth and Elan announced on Tuesday that the experimental drug for Alzheimer's disease patients that showed promise in Phase II clinical trials was into the final-stage trials.   

The Madison, New Jersey based Wyeth and its Irish partner Elan stated that a Phase 2 clinical trial of Alzheimer's treatment Bapineuzumab had yielded "encouraging preliminary findings."

In the Tuesday release, the drug makers claimed that bapineuzumab improved cognitive functioning in a subset of patients, those who did not carry a genetic variation called ApoE4. Noncarriers make up 40 to 70 percent of Alzheimer’s patients.

Anton Porsteinsson, director of Alzheimer's Disease Care at the University of Rochester Medical Center and one of the study's investigators said that the experimental drug showed promise in a comparative study conducted on the patients taking bapineuzumab and those taking placebo.

According to Porsteinsson, adverse side effects were reported in both placebo and drug groups. However, ankle swelling, which was reported in the drug group, was more common in ApoE4 carriers and those taking higher doses of the drug.

Bapineuzumab is designed to fight beta amyloid, a toxic protein that clumps together in the brains of Alzheimer's patients. It is considered the most promising of the Wyeth’s 23 Alzheimer’s products.