Dr Reddy's Laboratories has lost another major legal battle in the US, this time over Omeprezole, a generic heartburn drug, against the infringement of the patent held by Anglo-Swedish drug major AstraZeneca on Prilosec. AstraZeneca had sued Dr Reddy's and three other generic drug makers, in the District Court in New York, for infringing its patents on Prilosec which had a sales turnover of $3.70 billion in 2001 in the US alone.

The company had argued that the generic versions using the active ingredient Omeprezole had infringed both patents, `230 and `505, which deal with sub-coatings on the drug.

The District Judge, Barbara S Jones, has ruled that of the four generic drug makers, Dr Reddy's US subsidiary Cheminor and two other US companies, Andrx Corpn and Genpharm, had infringed the patents. But the judge held that the fourth, KUDCo, a unit of Schwarz Pharma of Germany, did not infringe the patents of AstraZeneca, because it used a different coating on the drug for which it had a patent until 2016. KUDCo's version of Prilosec had been approved by the US FDA as well.

While sources at Dr Reddy's confirmed reports from the US, they were unable to state the next course of action. It may be recalled that Dr Reddy's had sued the FDA in February this year for re-instatement of its 180-day marketing exclusivity for Omeprezole capsules. The FDA had granted the exclusivity to Andrx Corpn, the US generic drug maker, in November last year. DRL claimed that it had filed an ANDA for Omeprezole 40mg capsules in February 1999, following which AstraZeneca sued the company and other applicants for patent infringement. However, in May last year a New York court had ruled that the patent was not infringed by Dr Reddy's.

Dr Reddy's suit against the FDA is still pending though arguments in the case had been completed in June. The judge was apparently waiting for the verdict in the main case filed by AstraZeneca. How the latest judgement would impact Dr Reddy's suit against the FDA is not known.

Two months ago, Dr Reddy's had lost a battle in the District Court in New Jersey in a patent infringement case against the German pharmaceutical giant Bayer AG. The court had upheld the validity of Bayer's patent `444 on Ciprofloxacin, an anti-microbial drug. DRL had approval from the FDA to launch generic Ciprofloxacin in 100mg, 250mg, 500mg and 750mg in tablet form. Dr Reddy's now expects to launch the drug in the US market after Bayer's patent expires in December 2003.