Early treatment and dose optimisation BENEFIT and BEYOND.

The use of interferon beta (IFNbeta) in the treatment of multiple sclerosis (MS) has not changed greatly since its introduction. However, two new treatment paradigms have recently emerged-initiation of treatment as early in the course of the disease as possible and the use of higher doses with greater frequency to gain maximum therapeutic effect. The rationale for early treatment comes from evidence showing that early and irreversible pathology exists in very early stages of relapsing remitting MS (RRMS) often before significant disability is apparent and continues during remission. In addition, irreversible axonal damage begins early in the course of MS. Two relatively short-term studies indicate that it is possible to delay the onset of MS by early treatment with low-dose IFNbeta-1a. The BENEFIT (BEtaferon/Betaseron in Newly Emerging MS For Initial Treatment) study is being undertaken to investigate whether early intervention with a high-dose and more frequent administration of IFNbeta-1b (250 microg [8 MIU] every other day [eod]) has the ability to affect long-term clinical and magnetic resonance imaging (MRI) outcomes even more favourably. In addition, together with its follow-up study, BENEFIT will address the open question of long-term effects of early treatment on disease progression. Results from the pivotal IFNbeta-1b study, together with data from PRISMS (Prevention of Relapses and Disability by Interferon beta-1a Subcutaneously in Multiple Sclerosis) showed the presence of a dose-response relationship for IFNbeta in the treatment of RRMS. This finding was confirmed by the results of INCOMIN (INdependent COMparison of INterferons) and EVIDENCE (EVidence of Interferon Dose-response: European North American Comparative Efficacy), direct comparative studies of high-dose (250 microg IFNbeta-1b, 44 microg IFNbeta-1a), high-frequency versus lower dose (30 microg IFNbeta-1a) and less frequent IFNbeta regimens. Results from a pilot study in patients with RRMS have indicated that increasing the dose of IFNbeta-1b to 500 microg (16 MIU) had a more pronounced biological effect compared with the standard 250 microg dose. The BEYOND (Betaferon/Betaseron Efficacy Yielding Outcomes of a New Dose) study is being undertaken to investigate whether IFNbeta-1b 500 microg eod is superior to the standard 250 microg eod dose in treatment-naïve patients with RRMS. A third treatment arm will provide a comparison with glatiramer acetate 20mg subcutaneously once daily.