BMS wins six more months for Plavix

Bristol-Myers Squibb (BMS) and sanofi-aventis (S-A) have won an additional six months of US marketing exclusivity for their blood-thinner Plavix (clopidogrel bisulfate), which is the world's second-best-selling drug and brought in $9.1bn in global sales in 2009, with $5.6bn of that total generated in the US.

The companies have been granted the additional exclusivity through the US Food and Drug Administration's (FDA) paediatric exclusivity programme. The programme awards drug manufacturers an additional six months without generic competition in return for conducting paediatric studies of their products at the agency's request, as data on medicines in children is often scarce.

In this case, the FDA requested that the companies study Plavix in infants with heart defects. The study, which was conducted by BMS and enrolled more than 900 babies, failed to show a benefit for the drug. However, the paediatric exclusivity programme rewards companies for conducting studies whether or not the outcome is successful.

Plavix had been scheduled to lose patent exclusivity and become vulnerable to lower-cost generics by November of this year. However, because paediatric exclusivity attaches to the end of existing patent periods rather than running concurrently, the FDA will now hold off on allowing generics to come to market until May 17, 2012.

The extension on the exclusivity of the mega-blockbuster drug is a bright spot for BMS and S-A, both of which are struggling with the effects of generic competition for other key products. S-A's deep vein thrombosis treatment Lovenox (enoxaparin) recently lost its US exclusivity, and Bristol-Myers has five major products that will go off patent before 2015.