This is a multi-center, open Label, non-comparative Phase IV trial. Eligible Patients will receive treatment with Interferon-beta-1a (AVONEX) 30mcg I.M. once weekly for up to 12 months.
In the wash-out period prior to commencing treatment with AVONEX, patients will receive treatment with intermittent Methylprednisolone 500 mg PO Daily for three consecutive days at monthly intervals.
The patients will be examined clinically and laboratory tests will be performed at screening (month -1) and after 3, 9, and 15 months.
Neutralizing antibody(NAb)titres and Binding antibody(BAb)titres as well as MxA protein levels will be evaluated at screening/baseline (month -1/0) and after 3, 6, 9, 12, and 15 months.
