A Study to Assess Efficacy and Safety of Empasiprubart Versus IVIg in Adults With CIDP

The main purpose of this study is to compare empasiprubart and IVIg for treating people with CIDP. This study consists of a Part A where participants will either receive empasiprubart and a placebo resembling IVIg, or IVIg and a placebo resembling empasiprubart for 24 weeks (6 months). Following Part A, participants will enter Part B in which all participants will receive empasiprubart for 96 weeks (24 months). More information can be found here: https://clinicaltrials.argenx.com/emvigorate

Inclusion Criteria: * Meets criteria for CIDP based on EAN/PNS Task Force CIDP guidelines, second revision (2021) * Has either typical CIDP or 1 of the following CIDP variants: motor CIDP, multifocal CIDP (also known as Lewis-Sumner syndrome), focal CIDP, or distal CIDP * Has responded to IVIg in the past 5 years * Receiving treatment with IVIg within a standard optimal maintenance dosing regimen, with a minimum weekly IVIg dose of at least 0.125 g/kg * Has residual disability and active disease Exclusion Criteria: * Besides the indication under study, known autoimmune disease or any medical condition that would interfere with an accurate assessment of clinical symptoms of CIDP or puts the participant at undue risk, including polyneuropathy of other causes * Meets the criteria for possible or sensory CIDP based on EAN/PNS Task Force CIDP guidelines, second revision (2021) * Use of other long-acting immunomodulatory treatment