A Study of TAK-411 in Adults With Chronic Inflammatory Demyelinating Polyradiculoneuropathy (CIDP)

CIDP is an autoimmune disease. This means that the body's germ fighting (immune) system attacks itself. In CIDP, the immune system attacks the protective covering around the nerves called myelin. Over time, these nerves lose their ability to send signals to the muscles in the body. This leads to muscle weakness and loss of sensation in arms and legs among other symptoms. Participants with CIDP can be treated with a protein called immunoglobulin (or IG). TAK-411 is a special type of immune globulin G (hsIgG) that has been chemically changed. It is made from IG that comes from human plasma. This study will test if TAK-411 can decrease inflammation and improve symptoms of CIDP. The main aim of this study is to check how TAK-411 affects the physical functioning of adults with CIDP when compared with results of the placebo group of a historical trial. Participants may be treated with TAK-411 for up to 1 year (51 weeks) and will be followed up for 3 weeks after last dose. During the study, participants may visit their study clinic up to approximately 21 times.