[Use of interferon-β in the treatment of multiple sclerosis].

Interferon-β (IFNβ) products are widely used as first-line treatment for multiple sclerosis and have well-established benefit-risk profiles over the short- and long-term. Commercially available agents in Japan include subcutaneous IFNβ-1β (Betaferon) and intramuscular IFNβ-1a(Avonex). Although these IFNβ products differ in dosage, frequency of administration and rout of delivery, both reduce relapse rate by about 30% and new lesion activity by about 65%. In addition, IFNβ products were shown to reduce the disability progression. However, clinical studies have also demonstrated that a subset of patients respond poorly to IFNβ treatment. Thus, it is an important strategy to identify the patients who have suboptimal treatment responses early, before disability ensures, as measured by combination of clinical data and MRI measures of disease activity.