Berlex, the US subsidiary of Germany’s Schering AG, is seeking to extend the approved uses for its multiple sclerosis drug Betaseron in the USA to include patients with the first clinical signs of the disease.

Betaseron (interferon beta-2b) is already approved to treat relapsing forms of multiple sclerosis to reduce the frequency of clinical exacerbations, i.e. patients who have established MS. The new indication would make it possible for doctors to prescribe Betaseron to patients who have experienced a first clinical demyelinating event, in which the myelin sheath surrounding a nerve is lost.

The aim would be to retard the disease as early as possible after diagnosis and try to delay a second exacerbation.

Observers said approval of the new labelling for Betaseron, which could come before the end of the year, could help the drug compete against its rivals in the MS arena by making it more likely to be used in newly-diagnosed patients. These would likely be maintained on the drug as their disease progressed, rather than switched to an alternative.

Betaseron is facing stiff competition from other interferon beta products, including Serono’s Rebif and Biogen IDEC’s Avonex (both interferon beta-1a), but has been fighting back in recent months, with global sales up 12% in the fourth quarter of 2005 to 240 million euros ($286m).

Schering earlier this week it is exercising its right to buy the exclusive rights to the drug from current US partner Chiron, as a result of the latter’s takeover by Novartis.