Reuters reports that the launch of a generic version of blockbuster drug Plavix would cause "irreparable injury" if it did not stop, a lawyer for Bristol-Myers Squibb Co. and Sanofi-Aventis told a federal judge last Friday. The companies are seeking a preliminary injunction to halt sales by Canadian drug maker Apotex Inc., which last week shook up the industry by launching its generic of the $4 billion-a-year blood-clot treatment far earlier than analysts had expected. The hearing is part of the latest, and perhaps final, effort by Bristol-Myers to maintain its grip on its top-selling product, which accounts for an estimated 30 percent of profits. The company and Sanofi-Aventis are locked in a battle with Apotex over the drug''s patent. Bristol-Myers and Sanofi-Aventis also asked to recall supplies of the generic already in the marketplace. Privately-held Apotex, which launched its generic on August 8, is believed to have shipped huge amounts of its product after a settlement between it and the two larger drug makers collapsed late last month. Under the collapsed settlement, Apotex would have delayed its launch for years in exchange for compensation from Bristol-Myers and Sanofi-Aventis, which still claim the generic infringes a Plavix patent. The U.S. Department of Justice began a criminal antitrust investigation of the settlement, including a raid on the office files of Bristol-Myers Chief Executive Peter Dolan, only days before the settlement fell through.