Re: Vartanian T. An examination of the results of the EVIDENCE, INCOMIN, and phase III studies of interferon beta products in the treatment of multiple sclerosis. Clin Ther. 2003;25:105-118

Interferon-β1bfor multiple sclerosis

Interferon-beta1b (Betaseron/Betaferon) was the first approved therapy for relapsing-remitting multiple sclerosis. The US Food and Drug Administration has expanded the indication to include relapsing forms of multiple sclerosis which encompasses secondary-progressive multiple sclerosis if relapses are present. In one scientifically sound head-to-head comparison (Independent Comparison of Interferon trial), interferon-beta1b was shown to be clinically superior to low-dose interferon-beta1a (Avonex). Current studies are underway to compare it with a double dosage of interferon-beta1b [corrected] as well as glatiramer acetate. Neutralizing antibodies are more likely to occur with interferon-beta1b, but their clinical significance has shown conflicting and confusing results making the utility of measuring neutralizing antibodies uncertain. Up to 12 years of follow-up data suggest that the drug remains effective on T2 magnetic resonance imaging burden of disease in those who stay on therapy. Initially, the major problem with interferon-beta1b was a lack of tolerability due to high incidents of skin reactions and influenza-like side effects. Patient adherence has improved dramatically with the introduction of autoinjectors and protocol changes including initial dose escalation, prophylactic ibuprofen or acetaminophen, evening administration of drug and an attentive nurse support system. Interferon-beta1b remains a first-line treatment for relapsing-remitting multiple sclerosis and relapsing forms of secondary-progressive multiple sclerosis based on robust efficacy data and a long-term safety profile.

Interferon-β1bin multiple sclerosis

In 1993, interferon (IFN)-beta(1b) for subcutaneous injection became the first US FDA-approved immunomodulatory treatment for multiple sclerosis, a chronic inflammatory disease of the CNS. In this review of IFN-beta(1b), we first present a short introduction to multiple sclerosis and currently available therapeutics. We then summarize current knowledge about the biochemical structure of IFN-beta(1b), as well as pharmacokinetics and pharmacodynamics, including data on putative mechanisms underlying therapeutic as well as adverse effects. Furthermore, a critical review of ongoing and recently published clinical trials investigating IFN-beta(1b) in multiple sclerosis will be provided. Main topics are: trials investigating IFN-beta(1b) after a first clinical event, at higher dosages or in comparison to once-weekly subcutaneous IFN-beta(1a) injections, 16 years of long-term follow-up, IFN-beta(1b) in Japanese patients, the role of neutralizing antibodies, biomarkers for the prediction of therapy response, IFN-beta(1b) and pregnancy, and IFN-beta(1b) treatment of children with multiple sclerosis. Finally, we discuss how novel drugs, especially monoclonal antibodies and orally administered immunosuppressants, might soon challenge the position of this well-established agent on the multiple sclerosis therapeutics market.

Is multiple sclerosis a disease that requires frequent beta interferon dosing?

The three currently available beta interferon products for the treatment of patients with relapsing-remitting multiple sclerosis (RRMS) are administered according to different regimens. Placebo-controlled clinical trials support the efficacy of both alternate-day interferon beta-1b (Betaferon) and once-a-week interferon beta-1a (Avonex), but benefits to patients are probably dependent on the regimen used. Once-weekly administration, perceived to have fewer adverse events and greater convenience, may improve compliance, whereas frequent administration might enhance efficacy. However, more frequent administration is also associated with an increase in neutralising antibody (NAb) production, relative to once weekly treatment. The issue of NAbs is complex, and their clinical relevance, if any, has yet to be fully assessed. Pharmacological evidence suggests that the effects of beta interferon on a number of biological markers is maximised when administered every 48 hours. This might arise as a result of sustained activity in the intracellular molecular signalling pathways regulating beta interferon-induced gene expression. Some evidence suggests that the increase in biological effect at higher more frequent doses is mirrored by improvements in clinical and MRI outcome measures. Two recent comparative studies demonstrated significantly better clinical and magnetic resonance imaging outcomes in patients with RRMS receiving alternate-day high-dose interferon beta-1b (250 micro g subcutaneously) or three-times-weekly high-dose interferon beta-1a compared to those receiving once weekly low-dose interferon beta-1a (30 micro g intramuscularly). Despite some methodological drawbacks, these studies indicate that the benefits of high-dose frequently administered beta interferon on relapse rate are seen soon after beginning treatment. Therefore, it seems appropriate to begin the treatment of RRMS with this dosing regimen.