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.
Systemic recombinant human interferon-beta treatment of relapsing-remitting multiple sclerosis: pilot study analysis and six-year follow-up.
A pilot study was undertaken to test the safety and establish the side effect profile of recombinant human interferon-beta 1b (Betaseron, Berlex Laboratories, Richmond, CA), in patients with relapsing-remitting multiple sclerosis (RRMS). During the initial dose finding period (24 weeks), five groups of 6 patients each were treated by subcutaneous injection three times each week with either 0.8, 4, 8, or 16 million units (mU) of Betaseron or placebo (WHO Standard). Although some side effects were noted in all groups, a dose-related trend in reduction of exacerbation frequency and side-effect profile was noted. Patients given 16 mU had no exacerbations during the initial dosing period, but associated side effects led to dose reduction or dropout. An 8 mU dose was selected for further study after 24 weeks, and continuous dosing at 8 mU in 15 patients has now exceeded 6 years. Side effects abated over time. Neutralizing antibody developed in most patients, but titers were variable, fluctuated independently of clinical course, and tended to fall with prolonged treatment. A dose-dependent rise in neopterin levels was observed during the initial dosing period. This pilot study has demonstrated responsiveness to Betaseron, shown a stable safety profile over time, and established guidelines for a dosing regimen to evaluate and optimize further the efficacy of Betaseron in RRMS.