OBJECTIVES: Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) is a rare autoimmune disorder characterized by distal/proximal weakness and/or sensory deficits. The objective was to analyze the effect of efgartigimod on treatment convenience, effectiveness and overall satisfaction in CIDP patients.

METHODS: ADHERE is the largest CIDP trial conducted in which efficacy of efgartigimod was demonstrated. In the open-label stage A, all patients (n=322) received efgartigimod for up to 12 weeks or until evidence of clinical Improvement (=response). Only responders were randomized in stage B, and received efgartigimod (n=111) or placebo (n=110) for up to 48 weeks or until evidence of clinical deterioration.

The Treatment Satisfaction Questionnaire for Medication (TSQM-9) assessed treatment convenience, effectiveness and overall satisfaction, with scores ranging 0-100. We compared the TSQM-9 scores of responders at the start of the run-in stage (corresponding to the prior treatment), last assessment of stage A and last assessment of stage B.

RESULTS: Between run-in and the last assessment of stage A, the mean treatment effectiveness and satisfaction score improved from 54.1(SE=1.6) to 63.9(SE=1.5) and from 55.6(SE=1.7) to 67.1(SE=1.5), respectively. During stage B, the mean effectiveness and satisfaction score remained at a similar level in the treatment group (effectiveness: 62.4,SE=2.2 to 63.6,SE=2.4; satisfaction: 65.4,SE=2.1 to 66.2,SE=2.4), while a worsening was observed in the placebo group (effectiveness: 65.5,SE=2.1 to 61.2,SE=2.4; satisfaction: 68.9,SE=2.0 to 63.5,SE=2.5).

For patients with IVIg/SCIg as prior treatment, the mean convenience score improved from 49.5(SE=2.4) to 65.8(SE=2.0) between run-in and the last assessment of stage A, while for patients with corticosteroids as prior treatment, the mean convenience score decreased slightly from 61.8(SE=2.6) to 58.1(SE=2.2).

CONCLUSIONS: CIDP patients responding to efgartigimod show an increase in patient-reported treatment effectiveness and overall treatment satisfaction compared to their prior treatment. Further efgartigimod treatment confirmed the stabilization of these findings, whereas a trend of worsening was observed in the placebo group.