AstraZeneca has launched a legal battle against Orion following the Finnish firm’s decision to sell generic versions of two of the Anglo-Swedish drugmaker’s best-selling products.

The drugs major has filed complaints to the Helsinki District Court concerning Orion’s versions of the antipsychotic Seroquel (quetiapine), which is already being sold as Ketpinor for 40% less than the original, and the prostate cancer treatment Casodex (bicalutamide). Finnish newspaper Helsingin Sanomat noted that Orion has a licence to sell the latter but it has not given a date for its introduction yet.

AstraZeneca believes that Seroquel has patent protection until 2012, and Casodex is covered for another year in Finland and is asking the court to decide whether Orion has infringed manufacturing patents on the two drugs. However, the newspaper reports that requests to stop sales of the drugs have been dismissed until Orion has responded to the complaint.

It appears that Orion has managed to take advantage of loopholes in Finland’s patent legislation. Pekka Kaivola, Orion's head of sales, told Helsingin Sanomat that the firm is working within the guidelines of laws which state that before 1995 it was only possible to protect the manufacturing process, and Orion insists that its versions of the two drugs are made in a different way from that used by AstraZeneca.

Mr Kaivola said that since 2003, Orion has introduced more than ten new generic products each year and has made sure that there are no patent problems.