Schering AG of Germany – a unit of Bayer – has been granted approval in Australia to market its multiple sclerosis drug Betaferon for patients in the early stages of the disease.

Betaseron (interferon beta-1b is the company's biggest-selling product but has been facing increasing competition of late from other MS products, including rival interferons from Biogen Idec and Serono and Teva's Copaxone (glatiramer acetate).

Approval in early MS could be critical for Betaferon, as it could mean that it captures patients newly-diagnosed with the disease before its rivals, and so stand a greater chance that Betaferon will be used as their symptoms progress.

According to the new labelling, early stage MS patients are defined as those who have experienced one first attack and have a magnetic resonance imaging (MRI) scan that shows features consistent with MS. Approval of this use in Europe was granted in June, with the USA giving the go-ahead last month. It is also cleared for the new indication in Canada.

- Schering has also confirmed that it is in litigation with Novartis in the USA over the rights to manufacture Betaferon.