ADHERE REAL will assess the real-world effectiveness of subcutaneous (SC) efgartigimod PH20 at managing patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and describe their treatment journey and healthcare resource utilization.

CIDP is a rare, immune-mediated polyradiculoneuropathy, characterized by progressive muscle weakness and sensory dysfunction. Efgartigimod, a human immunoglobulin (Ig)G1 antibody Fc fragment, reduces IgG recycling by blocking the neonatal Fc receptor, reducing impact on CIDP pathophysiology.

In the registrational ADHERE trial, SC efgartigimod PH20 was well tolerated and reduced the risk of CIDP relapse vs placebo; however, a need exists to understand the real-world experiences of patients being treated with efgartigimod PH20.

This real-world, prospective, multicenter study will assess approximately 200 adult patients with CIDP across the United States and Germany. Country-specific protocols will ensure adherence to national regulations and requirements. Patients will be efgartigimod PH20-treatment-naïve at the time of screening but prescribed to initiate efgartigimod PH20 in routine clinical practice.

Clinical scores (including clinician-assessed and patient-reported outcomes) will be recorded regularly, and any CIDP treatment/dosage changes or CIDP relapses will be recorded.

Change over time in various scores, including adjusted Inflammatory Neuropathy Cause and Treatment and Timed Up and Go, will assess real-world effectiveness of efgartigimod PH20, and will be monitored via patient questionnaires, nurse assessments, and medical record review. Proportion of participants with CIDP relapse and proportion with evidence of clinical improvement will be assessed.

Assessment of patient treatment journeys will include historical data (i.e. disease course, comorbidities, CIDP treatment, any modifications, and the timing/rationale for these changes). Healthcare resource utilization will be assessed by frequency, duration, and reasons for healthcare provider follow-ups, emergency room visits, and hospitalizations.

This study will expand on the results of the registrational ADHERE trial, providing valuable real-world insights about the long-term use of efgartigimod treatment in patients with CIDP.