Efficacy and Safety Study of Nipocalimab for Adults With Chronic Inflammatory Demyelinating Polyneuropathy (CIDP)

Inclusion Criteria: * Adults greater than or equal to (\>=) 18 years of age at the time of consent and as applicable, must also meet the legal age of consent in the jurisdiction in which the study is taking place * Diagnosed with Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) according to criteria of the European Academy of Neurology/Peripheral Nerve Society (EAN/PNS) 2021, progressing or relapsing forms. CIDP diagnosis to be adjudicated by independent committee during screening period * Inflammatory Neuropathy Cause and Treatment (INCAT) disability score between 2 and 9 at the Run-In Baseline visit for participants entering Run-In, or Stage A Baseline visit for participants directly entering Stage A. Participants with an INCAT score of 2 at trial entry must have this score exclusively from the leg disability score * Fulfilling any of the following treatment conditions: a) Currently treated with oral corticosteroids (CS) less than or equal to (\<=) 20 milligrams (mg)/day; or b) Currently treated with pulsed CS, and/or intravenous immunoglobulin (IVIg) or subcutaneous immunoglobulin (SCIg) and the participant is willing to discontinue no later than the run-in baseline visit; or c) Currently treated with oral CS greater than (\>) 20 mg/day and the participant is willing to taper to \<=20 mg/day during the run-in period; or d) Without previous treatment (treatment naive); or treatment with CS and/or IVIg or SCIg discontinued at least 3 months prior to screening (untre…