A judge in the USA has ruled that groups of Bristol-Myers Squibb shareholders can sue the firm over its handling of the high-profile patent dispute and settlement in 2006 concerning the bloodthinner blockbuster Plavix.

The case refers to disclosures B-MS made while settling patent litigation with Canadian generic firm Apotex over Plavix (clopidogrel). In his ruling, Judge Paul Crotty stated that two pension funds, the Ontario Teachers Pension Plan Board and the Minneapolis Firefighters' Relief Association, “have plausibly pleaded” that B-MS’ statements about the deal with Apotex “were rendered misleading by the failure to include relevant information about the nature of the settlement negotiations and the terms of the settlement agreement”.

The judge went on to say that the "plaintiffs have adequately alleged that a reasonable investor would have considered the undisclosed information material in making investment decisions." Judge Crotty added the shareholders had "plausibly alleged that B-MS' silence with regard to the details of the Apotex settlement made its public statements misleading or false”.

The pension funds had claimed that the New York-based drugmaker announced a deal with Apotex in March 2006 but did not disclose that it had agreed to limitations on damages and other provisions. B-MS says that its efforts to settle with the Canadian firm "were at all times full, fair and accurate" and that it "intends to vigorously defend itself as this litigation proceeds."

B-MS and partner Sanofi-Aventis sued Apotex for patent infringement in March 2002 but a statutory stay of the latter’s application with the US Food and Drug Administration to make a generic form expired in 2005, prompting Apotex to start selling its copycat version of Plavix. The attempted settlement was rejected a year later and in May 2007 B-MS pleaded guilty on two counts of making false statements to the US Federal Trade Commission concerning the botched settlement and agreed to pay a $1 million fine.