A Study to Compare TAK-881 and HYQVIA in Adults With Chronic Inflammatory Demyelinating Polyradiculoneuropathy (CIDP)

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 study includes a screening phase, a ramp-up phase (if needed), a HYQVIA treatment phase, a TAK-881 treatment phase, and an extension phase. Participants who have been receiving cIGSC or IGIV prior to the study will enter a HYQVIA ramp-up phase, starting 1 to 2 weeks after their last pre-study cIGSC or IGIV dose. Participants already on HYQVIA at the time of screening will proceed directly to the treatment phase. After the TAK-881 dosing phase, participants will move on to the TAK-881 extension phase, with the preference for subsequent infusions in the extension phase to be administered by the participant or caregiver at home.