GENERIC THREAT TO AUGMENTIN IN UK

SmithKline Beecham is facing a potential challenge to an important patent for its Augmentin (amoxicillin plus clavulanic acid) antibiotic from Norton Healthcare. The UK patent for clavulanic acid expires in April 1995 in the UK (2002 in the USA), but a formulation patent provides further protection beyond this date.

It is this formulation patent that Norton, a subsidiary of US company Ivax, is challenging. The company is seeking to have the patent revoked on the grounds of obviousness, ie no inventive step, and will also challenge the patent in other appropriate countries, according Lehman Brothers. Norton has already had successful patent challenges in the UK against Marion Merrell Dow over Seldane (terfenadine) and Bayer over Adalat (nifedipine). Augmentin's UK sales account for less than 1% of SB's world sales.