AstraZeneca bets on a blood drug with multibillion-dollar potential

AstraZeneca (AZN) has had a good week with its anticlotting drug Brilinta (ticagrelor). It impressed many observers by announcing positive results of a late-stage head-to-head study and a mid-stage study for Brilinta, and on Thursday, it said it had filed for Food and Drug Administration approval. Brilinta could be on the way to becoming a megablockbuster drug.

Study results for the experimental drug -- which fights acute coronary syndrome -- were first presented Sunday. For the study's 8,430 sickest patients, those taking the drug suffered fewer serious cardiovascular events (or deaths) than those taking Plavix, from Bristol-Myers Squibb (BMY) and Sanofi-Aventis (SNY).