"Encouraging" Alzheimer's news: Biogen Idec's drug aducanumab has been shown to slow mental decline in patients with early or mild Alzheimer's disease in a small drug trial, the full results of which were released Friday. The New York Times reports 166 patients were randomly given low to high doses of the drug (meant to eliminate amyloid plaque in the brain) or a placebo. Experts say the trial was designed to assess aducanumab's safety rather than effects, but the drug proved to be the first to both ease plaque and slow cognitive decline, Forbes reports. "It would be kind of hard to get those kind of results by chance," a doctor says. Another adds the drug was "impressive" when taken in the highest dose. Over a year, placebo patients fell 3.14 points on a 30-point cognition scale, while those taking the highest dose dropped 0.58 points. Patients on a middle dose slid 0.75 points.
Researchers caution, however, that taking the drug, also known as BIIB037, in the highest dose led to swelling in the brain at a higher rate than with other drugs in its class. About 55% of high-dose patients with the genetic variant ApoE4 reported the side effect, compared to 17% without the variant; the side effect hit 11% of middle-dose patients without the variant. Some 22% of patients also reported headaches, the Wall Street Journal reports. Many believe amyloid plaque causes dementia, yet other drugs designed to prevent or remove the plaque have failed. To boost the chance of success, Biogen used an imaging technique to ensure patients had plaque in their brains. Researchers note that other drugs that looked promising in early trials proved ineffective in larger ones; Biogen is now planning a trial of 1,000 patients. Forbes reports that a positive result could push the drug to market by 2020. (A doctor claims his simple, three-step test could predict Alzheimer's, and ultrasound has also shown potential in restoring memories.)