Additional Study Information: This study is a Phase 2b, Multi-center, Randomized, Quadruple-blind, Placebo-controlled Study of Batoclimab Treatment in Adult Participants with Active Chronic Inflammatory Demyelinating Polyneuropathy CIDP): patients who are being treated with batoclimab defined as intravenous immunoglobulin IVIg, subcutaneous immunoglobulin SCIg) or plasma exchange (PLEX) treatment and the drug is not FDA approved. The mechanism of action of batoclimab is to inhibit FcRn-mediated recycling of IgG antibodies thereby decreasing IgG including autoreactive IgG levels in the circulation. In Period 1, all participants will be randomized (1:1) to receive batoclimab 680 mg SC QW or batoclimab340 mg SC QW for 12 weeks. In Period 2, participants in the randomized withdrawal population will be randomized (1:1) to batoclimab340 mg SC QW or PBO for up to 24 weeks. Participants must be 18 years of age or greater at the time of signing the informed consent.