LONDON ¿ Serono SA, Europe¿s largest biotechnology company, has stepped up its war of words with Biogen Inc. over claims for their competing products for the treatment of multiple sclerosis.

The two are disputing a ruling of the court in Geneva, Serono¿s home town, requested by Biogen in a bid to prevent Serono from repeating claims that Serono¿s drug Rebif is better than Biogen¿s Avonex. Biogen claimed in a press release Saturday that the Geneva court had upheld an earlier injunction of June 21 barring Serono from making comparative claims about the efficacy of Rebif.

Serono put out its own release Sunday saying, ¿This press release by Biogen claiming victory is outrageous, egregious and completely misleading.¿

Serono¿s claim that Rebif is superior is based on the findings of a clinical trial conducted by Serono called the Evidence study, in which Avonex and Rebif were directly compared.

A Serono spokesman told BioWorld International, ¿The ruling reaffirms our right to give details of the Evidence study to clinicians, and, critically for us, the court agrees that the FDA did approve the parameters of the study, which Biogen claims it did not.¿

According to Serono, the court ruling (which was delivered in French) also affirmed that the Evidence study is a ¿serious and properly conducted scientific study, with the clear objective of showing the superiority of Rebif over Avonex on the agreed endpoints needed to gain access to the U.S. market in the context of the Orphan Drug Act.¿

Rebif is the largest selling treatment for multiple sclerosis in most markets apart from the U.S., where Biogen¿s Avonex has orphan drug status protecting it from competitors until 2003. Serono has been pushing the FDA to end Avonex¿s special status on the grounds that Rebif is more effective.