Our review should provide some guidance to clinicians and patients. On the basis of high quality evidence, natalizumab and IFNß-1a (Rebif) are superior to all other treatments for preventing clinical relapses in RRMS in the short-term (24 months) compared to placebo. Moderate quality evidence supports a protective effect of natalizumab and IFNß-1a (Rebif) against disability progression in RRMS in the short-term compared to placebo. These treatments are associated with long-term serious adverse events and their benefit-risk balance might be unfavourable. IFNß-1b (Betaseron) and mitoxantrone probably decreased the odds of the participants with RRMS having relapses, compared with placebo (moderate quality of evidence). The benefit-risk balance with azathioprine is uncertain, however this agent might be effective in decreasing the odds of the participants with RRMS having relapses and disability progression over 24 to 36 months, compared with placebo. The lack of convincing efficacy data shows that IFNß-1a (Avonex), intravenous immunoglobulins, cyclophosphamide and long-term steroids have an unfavourable benefit-risk balance in RRMS. None of the included treatments are effective in decreasing disability progression in patients with progressive MS. It is important to consider that the clinical effects of all these treatments beyond two years are uncertain, a relevant point for a disease of 30 to 40 years duration. Direct head-to-head comparison(s) between natalizumab and IFNß-1a (Rebif) or between azathioprine and IFNß-1a (Rebif) should be top priority on the research agenda and follow-up of the trial cohorts should be mandatory.
Interferon beta-1b in secondary progressive MS: results from a 3-year controlled study.
To evaluate the efficacy and safety of interferon beta-1b (IFNbeta-1b) in subjects with secondary progressive multiple sclerosis (SPMS).
                This 3-year, multicenter, double-blind, placebo-controlled, randomized trial of IFNbeta-1b included 939 subjects from the United States and Canada with SPMS and Expanded Disability Status Scale (EDSS) scores ranging from 3.0 to 6.5. Subjects were randomly assigned to receive either placebo or IFNbeta-1b (250 microg or 160 microg/m2 body surface area), administered subcutaneously every other day. The primary outcome was time to progression by > or =1.0 EDSS point (0.5 point if EDSS score was 6.0 to 6.5 at entry) confirmed at 6 months. Secondary outcomes included mean change in EDSS score from baseline, relapse-related measures, MRI activity, and a standardized neuropsychological function test.
                There was no significant difference in time to confirmed progression of EDSS scores between placebo-treated patients and either of the IFNbeta-1b treatment groups. However, IFNbeta-1b treatment resulted in improvement on secondary outcome measures involving clinical relapses, newly active MRI lesions, and accumulated burden of disease on T2-weighted MRI. Effects were similar for both IFNbeta-1b treatment groups. Neutralizing antibodies to IFNbeta-1b were detected in 23% of 250-microg and 32% of 160-microg/m2 recipients, but their presence did not consistently affect clinical or MRI outcomes. IFNbeta-1b was also well tolerated at both doses.
                Although no treatment benefit was seen on the time to confirmed progression of disability, relapse- and MRI-related outcomes showed significant benefit with both dosing regimens tested, a result consistent with the outcomes of earlier clinical trials.