Chronic Inflammatory Demyelinating Polyradiculoneuropathy (CIDP) is a condition where the immune system mistakenly attacks the myelin, the protective layer around nerves. This can cause weakness and numbness in the arms and legs. Immunoglobulin (IG) is a protein used to treat CIDP. This study is exploring if a new form of this protein, called TAK-411, can help reduce the inflammation and improve symptoms.

Participants in this study will take TAK-411 for up to 51 weeks (almost a year) and will have a follow-up for 3 weeks after their last dose. During this time, they may have to visit the study clinic up to 21 times.

• Study Duration: Participation is up to 54 weeks (51 weeks treatment + 3 weeks follow-up).
• Visits Required: Up to 21 visits to the study clinic.
• Eligibility: Must be 18 or older with a confirmed diagnosis of typical CIDP.

This study will check if TAK-411 can help people with CIDP better than past treatments. Participants will be closely monitored to ensure safety and effectiveness.