Rebif® Quality of Life (RebiQoL): A randomized, multicenter, Phase IIIb study evaluating quality-of-life measures in patients receiving the serum-free formulation of subcutaneous interferon beta-1a for the treatment of relapsing forms of multiple sclerosis

Background: In clinical studies, treatment with subcutaneous interferon beta-1a (IFN beta-1a) has been shown to reduce relapse rates and slow the progression of physical disability in patients with relapsing forms of multiple sclerosis (MS). A formulation of subcutaneous IFN beta-1a has been developed that is free of fetal bovine serum and human serum albumin. Objective: To evaluate (a) the impact on quality of life (QoL) and treatment satisfaction of transitioning from the original formulation of subcutaneous IFN beta-1a to the serum-free formulation in patients with relapsing forms of MS; and (b) the impact of dose titration versus non-titration during the transition on tolerability and patterns of analgesic use. QoL was measured by the Multiple Sclerosis Treatment Concerns Questionnaire Global Side Effects (GSE) score. Methods: Patients who had received the original formulation of IFN beta-1a subcutaneously for >= 24 weeks were randomized to receive the serum-free formulation of IFN beta-1a 44 mu g subcutaneously three times weekly for 12 weeks, with or without a dose titration over a 4-week period. After week 12, patients continued to receive serum-free subcutaneous IFN beta-1a during a safety extension phase until they completed between 84 and 112 weeks of treatment. The primary endpoint was the percentage change from baseline to week 12 in GSE score in all patients. Results: A total of 232 patients were randomized (titrated n=113; non-titrated n=119). The mean percent change (improvement) from baseline to week 12 in the GSE score was 5.0% (p<0.001 for mean change in GSE score from baseline); this change was similar between titrated and nontitrated patients and met criteria for non-inferiority to the original formulation. Adverse event (AE) incidence and use of analgesics for the treatment of flu-like symptoms (FLS) were less common in the titrated group. Few patients (<2%) discontinued due to AEs during weeks 0 to 12. Conclusion: Patients with relapsing forms of MS who transitioned from original-formulation subcutaneous IFN beta-1a to serum-free subcutaneous IFN beta-1a had overall improved QoL scores at 12 weeks of treatment. Titration during the transition resulted in a lower requirement for analgesic treatment of FLS and fewer AEs. (C) 2012 Elsevier B.V. All rights reserved.