Impact of peginterferon beta-1a and disease factors on quality of life in multiple sclerosis

Background The Phase III ADVANCE study has shown clinical benefits for peginterferon beta-1a 125 μg dosed every 2 weeks versus placebo at 1 year in patients with relapsing-remitting multiple sclerosis (MS). This study assessed the impact of peginterferon beta-1a and disease factors on health-related quality of life (HRQoL) using data from ADVANCE. Methods HRQoL was assessed at baseline and 12, 24, and 48 weeks using the 29-item Multiple Sclerosis Impact Scale (MSIS-29) and other generic HRQoL measures. Changes in scores from baseline within each group and differences in mean change from baseline between groups were evaluated. Post-hoc mixed-effects repeated measures analyses were performed to assess the impact of confirmed disability progression and relapses, and the interactions of treatment and these MS events on HRQoL. Predictors with p≥0.1 were excluded from the final models, unless they were clinically meaningful. Results Relapses and confirmed disability progression were major drivers of HRQoL. When comparing week 48 to baseline, in placebo-treated patients (n=500), confirmed disability progression was associated with a 6.0-point worsening (p<0.0001) of MSIS-29 physical scores, relative to a 1.9-point worsening (p=0.044) with peginterferon beta-1a every 2 weeks (n=512). Such findings were observed consistently with other generic HRQoL measures. Additionally, having a recent relapse (≤ days before the HRQoL assessment) was associated with a 10.0-point worsening (p<) of MSIS-29 psychological scores in placebo-treated patients, compared with a 3.5-point (p=0.031) worsening with peginterferon beta-1a every 2 weeks. Conclusion Treatment with peginterferon beta-1a could help to improve or maintain HRQoL in addition to clinical outcomes. Trial registration: ClinicalTrials.gov: NCT00906399.