Medco Health Solutions is launching a head-to-head clinical trial of two blood thinners to see whether a genetic subset of patients taking the well-established Plavix (clopidogrel, Bristol-Myers Squibb/Sanofi-Aventis) can achieve comparable outcomes to those on new contender Effient (prasugrel, Eli Lilly/Daiichi Sankyo), which is more effective overall but also more expensive.

The trial is part of the US-based pharmacy benefit manager’s Genetics for Generics strategy, which aims to optimise clinical outcomes from generic drugs while lowering healthcare costs. Plavix, the third biggest-selling medicine in the US market (2008 sales: US$4.9 billion) is facing generic competition in late 2011 when its patent expires.

The Genotype-Guided Comparison of Clopidogrel and Prasugrel Outcomes Study (GeCCO) will enrol more than 14,000 acute coronary syndrome patients who have been newly prescribed Plavix or Effient.

The trial will compare the effectiveness of the two drugs by measuring the rate of cardiovascular deaths, non-fatal heart attacks and non-fatal strokes over a six-month period. Enrolment will start this autumn and is scheduled to end in mid-2011, with the results of the GeCCO study to be presented by early 2012.

Specifically, the trial will look at whether the 70-75% of patients who were born with a normally functioning CYP2C19 gene, and are hence ‘extensive metabolisers’ of clopidogrel, have comparable outcomes to patients on prasugrel. The Lilly/Daiichi drug has shown superior efficacy to, but a higher risk of bleeding than, clopidogrel in head-to-head clinical trials.

To date, though, none of these trials has limited the study population to patients with a properly functioning CYP2C19 gene, Medco noted. The GeCCO study “could have important patient safety ramifications and significant cost implications for health plans that pay for these drugs”, it said.

Trials such as these “are necessary to show how innovation can derive greater value from what we spend on healthcare”, commented Michael Leavitt, former US secretary of health and human services. “Personalised medicine is the new frontier in making medication safer and more effective. What we learn from this study, and others like it, will save lives and money.”