Schering AG is reportedly considering whether to buy all the rights to its top-selling drug, the multiple sclerosis therapy Betaferon/Betaseron (interferon beta-1b), which pulled in sales of 627 million euros ($757.5 million) in the first nine months of 2005.

Schering owns worldwide marketing rights to the drug, while its partner, US group Chiron, manufactures it for the USA for around 22% of global sales. Under the terms of their partnership, if Chiron is taken over by another firm, an event due to happen later this year when Swiss drug heavyweight Novartis plans to take over the reigns, Schering has first dibs on Chiron’s rights to the product.

According to media reports, industry observers are expecting that Schering will go ahead and buy the rights, but should the German group elect not to do so, Novartis will be able to produce and market the drug from 2008.

Betaferon’s future is looking pretty promising, especially after data, released late last year, showed that the drug slashed the risk of developing full-blown multiple sclerosis in early-stage patients by 50% - opening the door to a potentially much bigger market. "The data on Betaferon will improve therapy options for the treatment of newly emerging MS," Dr Joachim-Friedrich Kapp, Head of Specialised Therapeutics at Schering, commented at the time. "They demonstrate the importance of treating patients early on to provide rapid, early control of progression to definite multiple sclerosis."