GSK profits hit by copycat drugs

Glaxosmithkline, the UK's largest pharmaceutical company, yesterday moved to shore up patents on its bestselling drug as it unveiled financial results ravaged by the arrival of copycat competitors to three previous blockbusters.

Glaxosmithkline, the UK's largest pharmaceutical company, yesterday moved to shore up patents on its bestselling drug as it unveiled financial results ravaged by the arrival of copycat competitors to three previous blockbusters.

The company said it planned to re-file US patents covering the combination of molecules behind Advair, the asthma treatment known in the UK as Seretide, which had sales of £6.5m a day in the first six months of the year.

A UK court ruled similar patents invalid in this country earlier this year. Advair is a combination of two existing drugs, and the High Court decided the idea of combining them was "obvious".

Jean-Pierre Garnier, GSK's chief executive, said there would be a "minefield" of patent issues around Advair after 2008, when the main ingredients lose protection in the US, the world's most lucrative drugs market. The combination patents are part of an effort to extend exclusivity on the drug into the next decade.

"We didn't like the way the patent was written. In order to win these cases you need a tightly defined set of claims and we thought these could be improved," Dr Garnier said.

A 22 per cent rise in sales of Advair in the first half of the year outstripped most City forecasts, and Dr Garnier said that although prescription growth had stalled over the spring, the product was growing strongly again.

Its success helped mitigate sliding sales of three previous blockbusters which have lost patent protection in the past 18 months and now face copycat competition. The three are: Paxil, the antidepressant sold as Seroxat in the UK; Wellbutrin, another antidepressant; and the antibiotic Augmentin.

Group turnover fell 6 per cent to £10bn and profits dipped 10 per cent to £3.2bn, but GSK shares rose 17p to 1,088p yesterday as Dr Garnier insisted the company would return to growth before the end of the year.