Patient-Reported Outcomes in Patients with Varying Clinical Disease Activity of Relapsing-Remitting Multiple Sclerosis in the DECIDE Study

Background: Relapses and disability progression (based on the Expanded Disability Status Scale [EDSS]) are typical relapsing-remitting MS (RRMS) clinical trial assessments. Relapses in RRMS patients can, but do not always, lead to confirmed disability progression (CDP). Patient-reported outcomes (PROs), such as the 29-item Multiple Sclerosis Impact Scale (MSIS-29) and the EQ-5D, are important for assessing the impact of MS on patient functioning and daily activities. PROs may provide information on the impact of RRMS beyond the tools typically used by physicians.

Objectives:  To evaluate PROs in RRMS patients grouped according to clinical disease activity based on CDP in the absence or presence of prior relapse in DECIDE.

Methods:  DECIDE was a randomized, double-blind, active-controlled study of daclizumab high-yield process (DAC HYP) 150mg subcutaneous every 4 wks vs interferon (IFN) beta-1a 30mcg intramuscular (IM) once weekly in RRMS. Patients were divided into 4 groups with increasing level of clinical disease activity: no relapses or CDP, relapses without CDP, CDP without prior relapses, and CDP with prior relapses (defined as onset of 24-wk CDP [≥1.0- or ≥1.5-point increase in EDSS score from baseline EDSS score ≥1.0 or 0.0, respectively, confirmed after 24 wks] within 90 days following a relapse). Mean change from baseline in MSIS-29 physical subscale (PHYS) score at Wk 96 was evaluated post hoc. Negative changes indicate improvement. MSIS-29 PSYCH and EQ-5D were also assessed.

Results:  At Wk 96, mean change in MSIS-29 PHYS for combined treatment groups was: −1.4 in patients with no relapses or CDP (n=1112); 1.3 in patients with relapses without CDP (n=528); 4.8 in patients with CDP without prior relapses (n=106); and 9.3 in patients with CDP with prior relapses (n=72). DAC HYP-treated patients generally reported numerically greater improvement or less worsening in MSIS-29 PHYS score vs IM IFN beta-1a-treated patients across disease activity subgroups, with greatest worsening in patients with CDP with prior relapses in both treatment groups. Similar patterns were observed with the other PRO measures.

Conclusions:  These findings were consistent with DECIDE clinical outcomes. PRO outcomes worsened as severity of clinical disease activity increased and DAC HYP showed greater improvement/less worsening in PROs across most clinical disease activity groups vs IM IFN beta-1a. PROs provided information on functional changes beyond that shown by clinical outcomes.