French drugmaker Sanofi-Aventis was forced to slash its 2006 earnings growth forecast to just 2% this morning, a far cry from the 12% predicted just last month, as generic competition in the USA to its blockbuster blood thinner Plavix (clopidogrel) could substantially eat into the firm’s profits.

The move was sparked by a court ruling in the USA last night which, although granting Sanofi-Aventis and partner Bristol-Myers Squibb’s request to barr the sale of Canadian group Apotex’ copycat drug until the pending patent lawsuit is resolved, stopped short of ordering a recall of the latter’s generic already on the market.

“Based on information circulating on the market, it is possible that prior to the imposition of the injunction Apotex had already sold sufficient quantities in the US to satisfy substantially all market demand through the end of 2006,'' Sanofi explained in a statement.

As the battle hots up, Apotex said it will appeal yesterday's ruling, but Sanofi and B-MS are adamant that the generic infringes their intellectual property rights, and say they will vigorously defend their drug, which brings in US sales of around $2.7 billion a year.

Earlier this year, B-MS and Sanofi-Aventis actually joined forces with Apotex under an agreement whereby the Canadian firm would agree not to launch a rival version before 2011 in return for an undisclosed sum. But this did not sit well with US regulators, concerned over the anti-competitiveness of such 'sweetheart' deals, so the deal was scrapped and Apotex went ahead and launched its generic anyway.

To lose the world's second biggest drug ahead of patent expiry would likely substantially hurt the companies' forecasts, particularly B-MS which has just turned the corner of one tumultuous period in its history and last week was looking forward to "a period of sustained sales and earnings growth over several years, beginning 2007," with new product revenues outweighing dramatic losses for several drugs, including its once top-seller Pravachol (pravastatin).

A new trial for the patent litigation has been set for January 22, 2007.