Anti-trust regulators in the USA are the latest group to launch an investigation into Bristol-Myers Squibb and Sanofi-Aventis’ controversial settlement with Canadian drugmaker Apotex last year that tried to delay a generic version of Plavix from hitting the market.

The US Federal Trade Commission has issued B-MS and partner Sanofi with a “civil investigative demand” requesting documents and information relating to the firm’s proposed settlement with Apotex of the high-profile patent litigation pending in a court in New York concerning the blockbuster antithrombotic Plavix (clopidogrel).

The sweetheart deal, which sought to keep the copycat version off the market until 2011, was invalidated by US lawmakers as anti-competitive and Apotex flooded the market with its generic clopidogrel for three weeks last summer before an injunction was put in place. However the series of events triggered a number of probes by legal authorities and in February, a prosecutor in New Jersey said B-MS did not violate securities laws in trying to delay generic Plavix. A separate criminal antitrust investigation by the US Justice Department is also pending.

B-MS and Sanofi said they intend to cooperate fully with the FTC investigation and the former added that “it is not possible at this time reasonably to assess” the outcome of the probe or of the investigation by the DoJ, “or their impact on the company". The firms are now waiting to see how the judge in the New York trial will rule on Apotex's request to declare the Plavix patent invalid and unenforceable and a decision could come as early as the end of April.

Switzerland approves Sanofi’s Acomplia

Meantime, Sanofi has received some welcome news regarding its anti-obesity drug Acomplia as Switzerland has given the treatment the green light.

The regulatory agency Swissmedic said that Acomplia (rimonabant) can now be prescribed, in conjunction with diet and exercise, for obese or overweight patients with at least one associated cardiovascular risk factor.