Serono's high-dose interferon-β-1a ['Rebif'] is more effective than Biogen's lower-dose formulation ['Avonex'] in the treatment of relapsing-remitting multiple sclerosis, according to results from the EVIDENCE*study presented at the Annual Meeting of the American Academy of Neurology [Denver, US; April 2002]. Data from 48 weeks' follow-up supported the conclusions drawn from the 24-week results of the study. At week 48, 62% of 'Rebif' recipients, compared with 52% of patients treated with 'Avonex', remained free of relapses.'This is a highly significant result for physicians and patients',commented presenter Dr Hillel Panitch from the University of Vermont College of Medicine, US. Moreover, analysis of the 24-week data showed that corticosteroid use for relapses, and also the proportion of active MRI scans, was significantly reduced in 'Rebif', compared with 'Avonex', recipients.