Tuesday, September 11 11:58:18
Data from two large studies of Pfizer Inc and Johnson and Johnson's Alzheimer's drug, bapineuzumab, show the treatment reduced underlying markers of the disease in some patients, suggesting the failed medication might work at an earlier stage.
The findings, presented at a European neurology meeting in Stockholm, followed the companies' announcement last month that they were scrapping large-scale clinical trials of the drug after it failed to improve memory or thinking skills in patients with mild to moderate Alzheimer's.
Many researchers had long expected bapineuzumab to fail this test because they believe Alzheimer's starts years before memory problems become apparent.
But they have been eagerly awaiting the so-called biomarker results - measurements of fluids and tissues in the body - to see if the drug hit its biological targets, suggesting it could work in at an earlier stage of the disease.
These biomarker results show that compared with the subjects who were give a placebo, bapineuzumab significantly reduced the amount of the protein beta amyloid on the brain scans of patients with a gene mutation that increases their risk of Alzheimer's.
The drug also significantly reduced the amount of a toxic form of the protein tau in spinal fluid, a sign of brain cell death, compared with patients who were given a placebo.
However, MRI tests showed patients in the treatment and placebo groups had a similar loss of brain volume.
Dr. Reisa Sperling of Harvard Medical School and Brigham and Women's Hospital, who presented results of a study of patients who carry the ApoE4 gene mutation, said the findings were not a "home run in biomarkers," but they are encouraging.
"I am happy there is evidence that we are having some effect on the disease process in the brain," she said in a telephone interview from Stockholm.
"I am very interested in moving towards a much earlier stage of Alzheimer's disease in which we might be able to impact the biology at time when we might prevent symptoms."
The results of a second trial of patients who were not carriers of the ApoE4 mutation, presented by Dr. Stephen Salloway of Brown University in Providence, Rhode Island, showed no improvements in any of these biomarkers. However, the follow-up study only included 39 patients and was likely too small to show much of an effect, Salloway said. (C ) Reuters