Mumbai, Sept. 1: In a setback to Dr Reddy’s Laboratories (DRL), a US district judge has barred Canadian company Apotex from selling the generic version of the best-selling blood thinner, Plavix.

Plavix is second to Pfizer’s Lipitor in global sales of prescription drugs.

While the court ruling means that Apotex cannot market the drug henceforth, the development is a disappointment for DRL as it was expected that the innovators will enter into an authorised generic agreement with DRL if the court gives its go-ahead for sale of the generic version. Authorised generics are generic versions of the branded drug, which can be produced with the innovator’s consent.

Such a business line is not new to DRL. In February, the company entered into the country’s first authorised generics deal with the US-based Merck to distribute and sell the generic versions of the latter’s Proscar and Zocor.

The court ruling would also mean that DRL will have to wait till 2011 for marketing Plavix when its patents expire. DRL had filed for an abbreviated new drug application (Anda) for Plavix way back in 2002.

Plavix, which recorded sales of around $6 billion in 2005, comes from the stable of Sanofi-Aventis. Bristol-Myers Squibb markets the drug in the US.

The drug is used by over 57 million Americans and it helps keep platelets in the blood from sticking together and forming clots, which can protect against heart attack or stroke.

In March, Sanofi-Aventis and Bristol-Myers Squibb entered into an agreement with Apotex.

Under the terms of the settlement, Apotex Inc will not sell the generic version of the drug until September 2011. As a compensation, Sanofi-Aventis and Bristol-Myers Squibb were supposed to pay an unspecified amount to Apotex.