BetaferonR is effective in reducing relapse rate and MRI T2-weighted lesion frequency in MS
patients at the dose of 8 MIU on alternate days (THE IFNB MS Study Group, 1993). Relapse rate
is reduced by 30-35% (The IFNB MS Study Group, 1993), MRI activity is decreased up to 100% in
most cases (Stone et al 1995). In some patients, however, MRI activity still occurs or
reappears during treatment (Stone et al 1995). MRI activity has been demonstrated to
correlate with relapse occurrence (McFarland et al, 1992; Miller et al, 1996), and in some
patients relapses still occur during IFN beta treatment. In other patients relapses may occur
in association with the appearance, after 9-18 months of treatment, of anti-IFN beta NAB (The
IFNB M S Study Group, 1995).
This protocol hypothesizes that the dose of 12 MIU BetaferonR on alternate days has more
pronounced MRI and clinical effects in MS patients than that of 8 MIU. MS patients who do not
respond to 8 MIU may take advantage of a higher dose. We, therefore decided to assess MRI
effects after increasing the Betaferon dose (12 MIU) in RRMS patients showing a residual MRI
activity (at least one new Gd enhancing lesion) during six months of standard Betaferon dose
treatment (8 MIU).