Comparative injection-site pain and tolerability of subcutaneous serum-free formulation of interferonβ-1a versus subcutaneous interferonβ-1b: results of the randomized, multicenter, Phase IIIb REFORMS study

Background In patients with relapsing–remitting multiple sclerosis (RRMS), subcutaneous (sc) interferon (IFN)β-1a and IFNβ-1b have been shown to reduce relapse rates. A formulation of IFNβ-1a has been produced without fetal bovine serumand without human serum albuminas an excipient(not currently approved for use in the US). The objectives of this study were to evaluate tolerability, injection-site redness, subject-reportedsatisfaction with therapy, and clinical safety and efficacy of the serum-free formulation of IFNβ-1a versus IFNβ-1b in IFNβ-treatment-naive patients with RRMS. The objectives of the extension phase were to evaluate long-term safety and tolerability of IFNβ-1a.