The aim of this study is to learn more about the following treatment options in adults with CIDP: * Subcutaneous self-infusion with HyQvia. * Intravenous infusion with Gammagard/Kiovig. Gammagard and Kiovig are the brand names for the same immunoglobulin compound. The study is in two parts. In Part 1, participants receive either HyQvia or a placebo subcutaneously. In Part 2 (only for participants who have a CIPD relapse during Part 1), participants will receive Gammagard Liquid/Kiovig intravenously. US participants will receive Gamunex-C. The first SC infusion will be given in the study clinic. The remaining SC infusions may be given in the study clinic or the participant's home. This will be decided by the study doctor and whether the participant or their caregiver can do the self-infusion.
Participants will receive HYQVIA/HyQvia SC which contains both Immune Globulin Infusion 10% (Human) (IGI, 10%) and recombinant human hyaluronidase (rHuPH20).
Participants will receive placebo solution (0.25% human albumin in Lactated Ringer's solution) and rHuPH20.
Participants will receive GAMMAGARD LIQUID/KIOVIG
Participants will receive GAMUNEX®-C
Ciudad Autonoma Buenos Aires, Buenos Aires, Argentina
Ciudad Autonoma Buenos Aires, Argentina
Ciudad Autonoma Buenos Aires, Argentina
Ciudad Autonoma Buenos Aires, Argentina