An Observational Study of Multiple Sclerosis (MS) Patients Starting or Restarting Baseline Treatment With Interferon Beta 1a After the Use of Escalation Treatment With Mitoxantrone

This was an open-label, multicentric, prospective, post-marketing surveillance (PMS) study to investigate whether baseline treatment with high-dose interferon beta 1a (Rebif 44 μg x 3 ), administered at a high frequency, leads to maintenance of stabilisation of the course of the disease in MS subjects previously treated with mitoxantrone. The previous mitoxantrone treatment of the included MS subjects was conducted in the course of a so-called escalation according to the immunomodulatory escalation treatment plan. An additional important aspect of the problem was the collection of safety and tolerance data during the observation phase.