GSK loses battle on Augmentin patents

The world's number two drug maker, GlaxoSmithKline, has failed in its attempt to reinstate patents on its best-selling antibiotic.

The company appealed against last year's US court ruling which invalidated a string of patents on the way it makes Augmentin, and allowed rivals to launch cut-price copies of the drug. It admitted yesterday that the US Court of Appeals had refused to overturn the ruling.

Augmentin's sales this year so far are down 35 per cent and the latest judgment will be a relief for the three generic drug makers - Teva of Israel, India's Ranbaxy and Geneva, a division of the Swiss giant Novartis - which risked serious damages if their early victory was reversed.

GSK said yesterday it was unlikely to press the patent issue further, but it continues to pursue Ranbaxy and Teva in a separate legal case. It accuses the pair of formulating their version of Augmentin using a strain of bacteria which, it claimed, was stolen from GSK laboratories by a disgruntled employee 14 years ago.

The market has long since given up on GSK reclaiming lost sales of its original Augmentin, and indeed the company's shares were up yesterday. The company is concentrating on marketing newer versions of the drug, a pill for children and an extended-release version for adults. The new products account for just over a third of GSK's Augmentin sales.