Pfizer and Bristol Myers Squibb's blood thinner apixaban beat aspirin in a study that may open the door to a multi-billion dollar-a-year market to prevent clots. Meanwhile, rival drug Xarelto made by Bayer delivered good results in dissolving potentially clots in the legs as well as preventing new ones--without causing either excessive bleeding or liver problems.
Apixaban, a Factor Xa inhibitor, was studied in the double-blind, randomized Averroes trial that recruited 5,600...