This is an explorative multi-centre, open label, non-comparative trial investigating whether it is possible to recover IFN-beta efficacy in breakthrough relapsing-remitting multiple sclerosis patients with high titres of neutralizing IFN-beta antibodies.
Prior to enrollment, treated MS subjects must have been on interferon-beta-1a or interferon-beta-1b for a minimum of 12 months and have reduced bioavailability as defined by the relative expression of MxA mRNA/GAPDH.
Subjects will complete a washout period with concurrent methylprednisolone 500mg PO daily for 3 days every month until they become Neutralizing Antibody negative. Subjects will then be challenged with AVONEX 30mcg IM weekly. Bioavailability will be measured every three months to determine return of biological activity. Clinical and MRI parameters, safety and tolerability will be compared to baseline to determine efficacy.
