®) in the treatment of multiple sclerosis

Correspondence: Fabio Monzani Department of Internal Medicine, University of Pisa, Via Roma 67, 56126 Pisa, Italy Tel +39 050 993 490 Fax +39 050 553 235 Email [email protected] Abstract: Interferon (INF) β 1a 22 or 44 μg (Rebif ) administered s.c. 3 times a week (t.i.w) is a well established immunomodulating treatment for relapsing remitting multiple sclerosis (RRMS). This review focuses on its mechanisms of action, evidence of effi cacy, safety, and tolerability. Several pharmacodynamic properties explain the immunomodulatory actions of INF β 1a 22 or 44 μg s.c. t.i.w. Pivotal trials and post-marketing studies proved that the drug is effective in reducing disease activity and likely in slowing disease progression. Head-to-head comparative studies with other marketed INFs β in RRMS suggested a better therapeutic response associated with higher doses and frequency of administration of Rebif . Additional evidence indicated a benefi cial effect of INF β 1a in patients with clinically isolated syndromes (CIS) suggestive of MS, as treatment reduced time to conversion to clinically defi nite (CD) disease. Further, although the drug did not prove to slow time to progression there were benefi ts on relapseand MRI-related secondary outcome measures in secondary progressive (SP) MS. Pivotal trials, their cross-over extensions, and post-marketing studies consistently showed that INF β 1a 22 or 44 μg s.c. t.i.w. is safe and well tolerated, as adverse drug reactions are usually mild and manageable.