- Patients who are randomized to their current standard-of-care IFN-β therapy for the first 6 months of the study must be willing to receive their treatment via the formulation provided in the study (i.e., Rebif 44 μg in a prefilled syringe or Betaferon/Betaseron 0.25 mg in single-use vials of lyophilized powder accompanied by a prefilled single-use diluent syringe).