Advancing treatment with interferon beta-1b (Betaferon/Betaseron) in the next decade--thinking beyond the standard dose.

Early therapeutic intervention with disease modifying agents in multiple sclerosis (MS) is recommended in an attempt to minimise damage to the central nervous system and improve clinical outcome. Interferon betas (IFN betas) are the most widely used approved therapies for MS at the present time. While optimal dosage and frequency of IFN administration is not fully known, evidence is growing that high-dose, high-frequency IFN beta may be the most effective regimen for controlling clinical activity and minimizing MRI lesion development for at least 1-2 years. Past experience demonstrates that commonly observed side-effects associated with IFN beta injections, such as flu-like symptoms and injection-site reactions, can be markedly reduced through a number of measures. Moreover, the incidence of these side-effects decreases with time. Taking these observations into account, it seems reasonable to consider increasing the maximum approved therapeutic dose of IFN beta-1b (Betaferon/Betaseron) in MS. It has recently been demonstrated that dose escalation of IFN beta-1b combined with pre-medication with ibuprofen enables doses as high as 500 microg every other day to be well tolerated. Further administration of IFN beta-1b (500 microg) in patients with hepatitis C revealed no safety or tolerability concerns, no unexpected or unusual symptoms and no relevant laboratory abnormalities during the 24-week treatment period. It is also noteworthy that the 500 microg dose produced a more marked increase in biological response markers (Mx protein) than that induced by the standard dose of IFN beta-1b, and that other studies have demonstrated similar effects on other such markers. Taken together, the available evidence provides a rationale for using an increased dose of IFN beta-1b in the treatment of MS. This will be investigated further in a new Phase III clinical trial (BEYOND).