DOW JONES NEWSWIRES Pfizer Inc. (PFE) and Medivation Inc. (MDVN) said that their investigational Alzheimer's treatment unexpectedly failed to meet cognition and global functioning efficacy goals in late-stage trials. Both companies will be reviewing the trial data to determine the next steps regarding the treatment, called dimebon. Shares of Medivation, which has no products on the market, were down 69% at $12.47 in recent premarket trading. Pfizer fell 1.4% at $17.35. The trial included 598 patients with mild-to-moderate Alzheimer's disease, who received either 20-milligram doses of dimebon, 5-milligram doses or a placebo over six months. Previous data showed that dimebon had potential for improved and longer-lasting effects than current treatments, along with reduced side effects. Dimebon is the subject of many other studies that could prove successful, and the drug also has shown effectiveness in another degenerative disease of the brain, Huntington's disease. Medivation also has a prostate cancer treatment, partnering with Astellas Pharma Inc. (4503.TO, ALPMY), and is developing a follow-up to dimebon that it fully owns. About 5.3 million people have Alzheimer's disease in the U.S., and it is the sixth-leading cause of death, according to The Alzheimer's Association. -By Tess Stynes, Dow Jones Newswires; 212-416-2481; Tess.Stynes@dowjones.com;
