The long-running legal wrangle over patents covering Pfizer’s high blood pressure medicine Accupril (quinapril) has taken another turn after a US appeals court overturned a summary judgement favouring the New York-based giant, which blocked sales of Ranbaxy and Teva’s generic version of the drug.

Earlier this year [[30/03/05a]], a preliminary injunction was served against

Teva and Ranbaxy, which launched a version of the drug in December

2004, after a US district court held that Pfizer was likely to prevail in an ongoing patent infringement lawsuit. However, the appeals court has now sent the case back to a lower court for further review.

The reason given is that: “Teva has presented fact-based arguments in support of its enablement defence that are deserving of consideration by the district court,” but no further details were given.

Pfizer said the ruling has no commercial impact on the sale of Accupril, as a June 2004 injunction is still in place, yet Ranbaxy shares benefited from the announcement and Teva’s stock also rose, though this was principally due to the fact that the US Food and Drug Administration gave tentative approval to the Israeli company’s application to market a generic form of Procter & Gamble’s osteoporosis drug Actonel (risedronate).