Interferon beta-1a and beta-1b for treatment of multiple sclerosis

Abstract

In their thoroughly planned and well done study, Luca Durelli and colleagues (April 27, p 1453)1Durelli L Verdun E Barbero P et al.Everyother-day interferon beta-1b versus once-weekly interferon beta-1a for multiple sclerosis: results of a 2-year prospective randomised multicentre study (INCOMIN).Lancet. 2002; 359: 1453-1460Summary Full Text Full Text PDF PubMed Scopus (489) Google Scholar compare every-other-day interferon beta-1b with weekly interferon beta-1a for treatment of relapsing-remitting multiple sclerosis.In the MRI groups, patients on interferon beta-1a seem to have more proton density lesions, enhancing lesions, and T1 hypointense lesions at baseline. I would like to know whether these imbalances were corrected for when calculating the significance of differences during the trial.Durelli and colleagues state that no analysis of the results was done before the end of 2000. However, the 1-year results were presented in spring, 2001.2Durelli L Ferrero B Oggero A et al.A multicentre trial comparing clinical and MRI efficacy of Interferon beta-1a and beta-1b in multiple sclerosis.J Neurol. 2001; 248: 62Google Scholar Since the study was unblinded, I wonder what effect the early presentation had on the continuing assessment of patients, at least in the 2nd year of the study, for number of relapses and confirmed score on expanded disability status scale. I also do not understand how this 1-year analysis is compatible with the investigators' statement that no interim analysis was planned and data were not monitored during the trial. Was there, therefore, no external quality control of the data provided by the participating centres, as is generally expected in studies done according to good clinical practice guidelines.3ICH E6 consolidated guideline on good clinical practice: CPMP/ICH/135/95. European Agency for the Evaluation of Medicinal Products (EMEA), London1997Google Scholar In their thoroughly planned and well done study, Luca Durelli and colleagues (April 27, p 1453)1Durelli L Verdun E Barbero P et al.Everyother-day interferon beta-1b versus once-weekly interferon beta-1a for multiple sclerosis: results of a 2-year prospective randomised multicentre study (INCOMIN).Lancet. 2002; 359: 1453-1460Summary Full Text Full Text PDF PubMed Scopus (489) Google Scholar compare every-other-day interferon beta-1b with weekly interferon beta-1a for treatment of relapsing-remitting multiple sclerosis. In the MRI groups, patients on interferon beta-1a seem to have more proton density lesions, enhancing lesions, and T1 hypointense lesions at baseline. I would like to know whether these imbalances were corrected for when calculating the significance of differences during the trial. Durelli and colleagues state that no analysis of the results was done before the end of 2000. However, the 1-year results were presented in spring, 2001.2Durelli L Ferrero B Oggero A et al.A multicentre trial comparing clinical and MRI efficacy of Interferon beta-1a and beta-1b in multiple sclerosis.J Neurol. 2001; 248: 62Google Scholar Since the study was unblinded, I wonder what effect the early presentation had on the continuing assessment of patients, at least in the 2nd year of the study, for number of relapses and confirmed score on expanded disability status scale. I also do not understand how this 1-year analysis is compatible with the investigators' statement that no interim analysis was planned and data were not monitored during the trial. Was there, therefore, no external quality control of the data provided by the participating centres, as is generally expected in studies done according to good clinical practice guidelines.3ICH E6 consolidated guideline on good clinical practice: CPMP/ICH/135/95. European Agency for the Evaluation of Medicinal Products (EMEA), London1997Google Scholar Interferon beta-1a and beta-1b for treatment of multiple sclerosisAuthor's reply Full-Text PDF