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 asapplicable, must also meet the legal age of consent in the jurisdiction in which thestudy is taking place

• Diagnosed with Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) according tocriteria of the European Academy of Neurology/Peripheral Nerve Society (EAN/PNS) 2021, progressing or relapsing forms. CIDP diagnosis to be adjudicated byindependent committee during screening period

• Inflammatory Neuropathy Cause and Treatment (INCAT) disability score between 2 and 9at the Run-In Baseline visit for participants entering Run-In, or Stage A Baselinevisit for participants directly entering Stage A. Participants with an INCAT scoreof 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 oralcorticosteroids (CS) less than or equal to (<=) 20 milligrams (mg)/day; or b)Currently treated with pulsed CS, and/or intravenous immunoglobulin (IVIg) orsubcutaneous immunoglobulin (SCIg) and the participant is willing to discontinue nolater than the run-in baseline visit; or c) Currently treated with oral CS greaterthan (>) 20 mg/day and the participant is willing to taper to <=20 mg/day during therun-in period; or d) Without previous treatment (treatment naive); or treatment withCS and/or IVIg or SCIg discontinued at least 3 months prior to screening (untreated)

• Active disease as determined by CIDP Disease Activity Status (CDAS) score >= 3

• Other protocol-defined inclusion criteria will apply

Exclusion Criteria:

• Has a history of severe and/or uncontrolled hepatic (example,viral/alcoholic/autoimmune hepatitis/cirrhosis and/or metabolic liver disease),gastrointestinal, renal, pulmonary, cardiovascular, psychiatric, neurological ormusculoskeletal disorder, hypertension and/or any other medical or uncontrolledautoimmune disorder(s) (example, diabetes mellitus) or clinically significantabnormalities in screening laboratory that, might interfere with the participantsfull participation in the study, or might jeopardize the safety of the participantor the validity of the study results

• Pure sensory CIDP or chronic immune sensory polyradiculopathy (CISP) (EAN/PNSdefinition)

• Any other disease that could better explain the participant's signs and symptoms,such as significant persisting neurological deficits from stroke or central nervoussystem (CNS) trauma or peripheral neuropathy from another cause such as connectivetissue disease or systemic lupus erythematosus

• Polyneuropathy of other causes, including the following: Multifocal motor neuropathy (MMN); Monoclonal gammopathy of uncertain significance with antimyelin associatedglycoprotein (anti-MAG) immunoglobulin M (IgM) antibodies; Hereditary motorneuropathy; Hereditary neuropathy with liability to pressure palsies (HNPP);Polyneuropathy, organomegaly, endocrinopathy, monoclonal protein and skin changesyndromes; Lumbosacral radiculoplexus neuropathy; Polyneuropathy most likely due todiabetes mellitus; Polyneuropathy most likely due to systemic illnesses; Drug- ortoxin-induced polyneuropathy Note: A concomitant polyneuropathy of other causes (example, a mild, stable diabetic polyneuropathy) is not necessarily exclusionary ifchronic inflammatory demyelinating polyneuropathy (CIDP) is confirmed as the maindiagnosis, as determined by the investigator and confirmed by the adjudicationcommittee

• Has known allergies, hypersensitivity, or intolerance to nipocalimab or itsexcipients

• Other protocol-defined exclusion criteria will apply