Having suffered a series of setbacks concerning its erythropoietin stimulating agents, Amgen thinks it finally has something to celebrate after a judge ruled that Roche’s new rival anaemia drug Mircera infringes one of the US biotechnology giant’s patents.

The US Federal District Court in Boston has ruled that Roche's Mircera (continuous erythropoietin receptor activator) will infringe Amgen's EPO pharmaceutical composition patent and has also granted summary judgment in favour of the latter firm on certain Roche defences against the patents-in-suit.

The case is going to trial on September 4, and Amgen says it continues to believe that its patents are valid and enforceable, and that Roche's peg-EPO product will infringe other patents relating to recombinant erythropoietin and its production. It added that Mircera “provides no clinical or patient benefit” to its own ESAs, Aranesp (darbepoetin alfa) and Epogen (epoetin alfa).

Amgen has suffered a knock from dwindling sales of Aranesp, leading the firm to announce job cuts of up to 14% of its workforce and the situation has not been helped by the effect of label changes, concerns over the safety of ESAs and changes in reimbursement in the USA. Therefore anything that can prevent a fresh competitor hitting the market would do Amgen the world of good.

However this early legal victory is not putting Roche off. Just last month, the European Commission backed Mircera for use in chronic kidney disease patients, although its hopes to get the drug onto the market in the USA were hit in May by the Food and Drug Administration only issuing an approvable letter for the compound.

As for the court battle with Amgen, the company issued a statement saying that “Roche remains confident in our position that all of the Amgen patents are invalid and not infringed. The trial has yet to begin. While we disagree with the judge on the matter of infringement, the ruling does not determine the ultimate validity of any Amgen patents”. One week to go but the gloves are already off.