De patienter, der fik lægemidlet, havde i gennemsnit 0, 84 attakker pr. år, mens de patienter, der fik placebo, havde 1, 27 attakker pr. år.
In patients with relapsing remitting MS, Betaferon was more effective than placebo in reducing the number of annual relapses: patients receiving the medicine had on average 0.84 relapses a year, when patients on placebo had 1.27.