French drugmaker Sanofi-Aventis suffered a series of setbacks over the past week involving two of its key products, and a highly awaited pipeline drug, as the firm scrapped plans for its rumored merger deal with Bristol-Myers Squibb. Today, the firm announced that the FDA has extended by three months its decision on whether to approve the highly anticipated developmental weight loss drug Acomplia. Sanofi-Aventis said the new action date by the FDA would now be July 27. The company initially expected to be able to begin selling Acomplia in the US in the second quarter of 2006 but the FDA asked for additional information about the drug last year pushing the expected approval date back to April 2007.The drugmaker did not give any reason for the FDA’s decision to extend the review period. Sanofi-Aventis has forecast sales of Acomplia at $3 billion, assuming it wins US approval. The drug has been on sale in Europe since last summer. On Monday, the FDA called on Sanofi-Aventis to revise its product labeling for its antibiotic Ketek, restricting use of the drug only to treat pneumonia and not less serious bacterial infections such as bronchitis and sinusitis, as previously indicated. “The agency has determined that the balance benefits and risks no longer support approval of the drugs for these indications,” the FDA said in a statement. The FDA also said Ketek’s labeling would bear a strong new “black box” warning, the strongest of its kind, outlining the drug’s risks and safe use. The warning states that Ketek should not be used in patients with myasthenia gravis, a disease that causes muscle weakness. The labeling changes are in line with the December recommendations of an FDA advisory committee which suggested Ketek should no longer be marketed for bronchitis or sinusitis. Ketek labeling already warns of the drug’s risk to the liver. An FDA review released in December cited 13 reports of liver failure in patients treated with the drug. The FDA announcement on Ketek’s labeling changes occurred on the eve of a House subcommittee hearing on drug safety to examine irregularities in the approval of Ketek. The FDA’s handling of Ketek is also under investigation by the Senate.Sanofi-Aventis said in a statement the company would inform healthcare professionals about the revisions through a “Dear Healthcare Professional” letter, sales force educational communications and the posting of updated prescribing information on company and product Web sites.In another product-related setback, a California court on Friday invalidated Sanofi-Aventis’ US patent on its top-selling product, the blockbuster blood thinner Lovenox.The decision marked a victory for Amphastar Pharmaceuticals and Teva Pharmaceutical Industries, which are seeking to launch generic versions of Lovenox. Despite their court victory, Amphastar and Teva face difficulties in getting their versions of Lovenox approved by the FDA. The drug, derived from pig intestines, requires a complex manufacturing process that is difficult to replicate. Lovenox is also under threat by generic drugmaker Momenta Pharmaceuticals, which has reportedly teamed with Novartis’ generics unit Sandoz. Sanofi-Aventis said in a statement that it is “currently evaluating its options for further legal recourse” and will continue to “vigorously defend its intellectual property rights.” In addition to Lovenox, Sanofi-Aventis is also defending its second best-selling product, the jointly marketed antiplatelet agent Plavix, in a US court. Sanofi-Aventis markets Plavix with Bristol-Myers Squibb. Worldwide sales of Lovenox for 2005 were $2.5 billion. Global sales of Plavix were $3.8 billion in 2005.Earlier last week, Sanofi-Aventis won FDA priority review for a new indication for Lovenox. The FDA will review Lovenox for treatment of patients suffering acute ST-segment elevation myocardial infarction (STEMI). STEMI is a heart attack in which an artery is generally completely blocked for enough time to cause heart muscle damage. The blockage is caused by blood clot formation in the heart arteries. Sanofi-Aventis said it also submitted the drug for the new indication in European countries including the UK, Spain, France, Germany and Italy. Lovenox is currently approved by the FDA for seven indications for the prophylaxis and treatment of thromboembolic disease. Meanwhile, rumored talks of a merger between Sanofi-Aventis and Bristol-Myers Squibb have been called off, according to a weekend report from The Times of London. Citing no sources, the report stated that Sanofi-Aventis ended its merger discussions due to disagreements over share price and legal disputes surrounding a court challenge to the US patent for Plavix. A pre-merger deal was thought to have been signed last month, according to an unsourced story in French financial newsletter La Lettre de l’Expansion. The acquisition of Bristol-Myers Squibb would have propelled France’s Sanofi-Aventis ahead of Pfizer as the biggest pharmaceutical company by sales and pushed GlaxoSmithKline into third place. Bristol-Myers has retained the investment bank Lehman Brothers to work alongside its existing bankers, Citigroup and Morgan Stanley, to advise it on its strategic options. Sources told The Times that no sale process was under way at present.