Researchers publish Plavix genotype analysis

Researchers at University College London published a meta-analysis showing no significant association between cytochrome P450 2C19 (CYP2C19) genotype and cardiovascular events in patients receiving Plavix clopidogrel. The results appear to contradict a 2010 black box warning added to Plavix's label about diminished effectiveness in patients with a genetic variation that reduces functioning of the CYP2C19 liver enzyme. The warning says that Plavix patients with the variant exhibit higher cardiovascular event rates following acute coronary syndrome (ACS) or percutaneous coronary intervention (PCI) than patients with normal CYP2C19 function. Bristol-Myers Squibb Co. (NYSE:BMY) and Sanofi (Euronext:SAN; NYSE:SNY), which could not be reached for comment, co-market Plavix. FDA said in a statement that it is reviewing the paper but believes there is still cause for concern with respect to patients who are poor metabolizers of Plavix.

The meta-analysis included 42,016 patients from 32 studies that reported clopidogrel metabolism, platelet reactivity, cardiovascular events and bleeding, and information on CYP2C19 genotype. Data were published in the Journal of the American Medical Association. ...