Chronic Inflammatory Demyelinating Polyradiculoneuropathy (CIDP)

The main purpose of the study is to determine the correct dose of empasiprubart in adolescent participants. It also aims to evaluate if empasiprubart may work and how safe it is for the use in children living with CIDP. The study consists of an open label treatment phase where participants will receive empasiprubart for up to 27 months approximately. After the final dose of empasiprubart, participants will enter a safety follow-up period for up to 14 months approximately. The overall study duration for each participant is up to 43 months. More information can be found here: clinicaltrials.argenx.com/emlight

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.

The main aim of this study is to evaluate the pharmacokinetic (PK) comparability between TAK-881 and HYQVIA subcutaneous (SC) administration for maintenance therapy of CIDP. The participants who are already receiving intravenous immunoglobulin G (IGIV), conventional subcutaneous intravenous immunoglobulin G (cIGSC), or HYQVIA will be treated with the same dose equivalent as their prior IG treatment with HYQVIA for 20 weeks followed by TAK-881 for 24 weeks. Participants will need to visit the clinic every 3 or 4 weeks until they enter the extension phase. In the extension phase, home infusions are allowed, and visits will occur between every 12 weeks and 24 weeks.

The main aims of this study are to understand why adults with Chronic Inflammatory Demyelinating Polyradiculoneuropathy (CIDP) chose a certain treatment, why they changed to HyQvia from another therapy, how satisfied they are with HyQvia and their previous treatment, how their work productivity and activity is impacted and learn about their CIDP signs and symptoms. Other aims are to collect information on any medical problems or side effects during the treatment with HyQvia, learn how effective treatment of CIDP with HyQvia is and understand details on the use of HyQvia in standard clinical routine as well on the need for healthcare intervention (such as emergency room visits or hospital visits or stays). During the study, data will be collected from medical records already available, interviews with participants at study start and study completion and via questionnaires completed by participants. Participants will be treated as per the doctor's or the clinic's routine.