Induction therapy for patients with multiple sclerosis: why? When? How?

The concept of induction treatment followed by long-term maintenance treatment in multiple sclerosis (MS) has attracted considerable attention. The combination of mitoxantrone as the induction therapy followed by an immunomodulatory drug (e.g., interferon beta or glatiramer acetate) as the maintenance therapy is of particular interest. This approach is suitable for patients with particularly aggressive disease, characterised by frequent relapses with incomplete recovery and the accumulation of focal lesions visible on magnetic resonance imaging. A long-term study has shown that a short (6 month) course of mitoxantrone followed by maintenance therapy with an immunomodulatory drug brings about a rapid reduction in disease activity and subsequent sustained disease control for at least 5 years. Furthermore, randomised studies have demonstrated that induction with mitoxantrone followed by maintenance treatment affords better disease control than monotherapy with an interferon beta. Natalizumab is also effective in patients with very active MS, but has a propensity to result in rebound inflammatory disease activity on withdrawal. More recently, a mere 5-day course of 12-mg intravenous perfusions of alemtuzumab was found to bring long-term clinical benefits in early relapsing MS patients at risk of developing severe systemic autoimmune disease within the space of a few years.