ICAD: Alzheimer's Studies Show Mixed Results
Phase 3 tarenflurbil study is disappointing, but studies of other agents suggest benefits
TUESDAY, July 29 (HealthDay News) -- Despite a phase 3 study showing that the anti-amyloid drug tarenflurbil is ineffective against Alzheimer's disease, studies of other agents show possible benefit, according to research presented this week at the 2008 Alzheimer's Association International Conference on Alzheimer's Disease in Chicago and published in The Lancet Neurology.
In one study, Robert C. Green, M.D., of the Boston University School of Medicine and colleagues conducted an 18-month multicenter phase 3 trial of tarenflurbil and found that the drug did not achieve statistical significance in either of its primary endpoints: improvements in cognition and activities of daily living.
In a second study, Jeffrey L. Cummings, M.D., of the David Geffen School of Medicine at UCLA and colleagues conducted a 12-week phase IIa trial of PBT2 -- which reduces the toxic form of amyloid -- and found that the drug significantly reduced levels of a protein biomarker for Alzheimer's disease and improved Trail Making Test Part B and Category Fluency Test scores. The study has been released early online in The Lancet Neurology. In a third study, Claude M. Wischik, M.D., of the University of Aberdeen in the United Kingdom and colleagues conducted a trial of methylthioninium chloride (remberTM)-- a tau aggregation inhibitor -- and found that the drug significantly improved cognitive function as measured by the ADAS-cog units in patients with moderate but not mild Alzheimer's disease.
"While the results of the trial were certainly disappointing, just because the Flurizan Phase III clinical trial failed, doesn't mean that other amyloid-targeted therapies in the clinical trial pipeline aren't valid," Samuel Gandy, M.D., Ph.D., chair of the Alzheimer's Association's Medical and Scientific Advisory Council, said in a statement. "We learn a great deal from every clinical study."
Several researchers in these studies report financial connections with pharmaceutical companies.