Study-data conflicts complicate Plavix research

Clinical data proliferation, while shining light into previously dark drug development corners, also is complicating the trial manager's job. And some may even be thinking that too much data is a clinician's curse.

Take the case of Plavix. The anticoagulant was awarded a black box warning last spring, following data that showed mutations in the CYP2C19 gene affect patient response to the drug and puts some of them at increased risk for heart attack and stroke. Then came the CYP2C19 genetic variant test to screen out those who might be so affected.

Given pending pipeline competition, Plavix makers Sanofi-Aventis and Bristol-Myers Squibb undertook another study. They found that, regardless of CYP2C19 genotype, the drug reduced the rate of cardiovascular death, MI and stroke in certain patients compared with placebo.

So, do the variants influence outcomes? And what effect does the conflicting data have on patient treatment?

The manufacturer-sponsored trial result likely throws into question decisions made since the black box warning appeared, says GenomeWeb. Resources budgeted for CYP2C19 testing may now be on the high side, if such testing is necessary at all.

- here's the article

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