Shares in Sanofi-Aventis rose yesterday after the French drugmaker said that a Canadian court had rejected a challenge from generics manufacturer, Apotex, on the patent covering its top-selling clot busting agent, Plavix (clopidogrel).

Apotex first challenged the patent back in 2003, but the court in Ottawa has asserted that, amongst other things, the firm had infringed the Plavix patent. Sanofi-Aventis’ share price rose by more than 4% to a new year-high in New York yesterday as investors welcomed the news. Many observers see this trial as key to paving the way ahead for the generic challenge that is currently pending in the US [[09/12/04e]].

Apotex and Dr Reddy’s Laboratories have been challenging the Plavix patent since 2002 [[04/04/02b]]. Although Dr Reddy’s claims that three patents covering Plavix in the USA are invalid, and has filed for approval of its generic formulation, Sanofi-Aventis asserts that the central patent covering the compound in this market does not expire until 2011. April 8 has been set for the submission of the “pre-trial” order [[25/02/05g]].