Extension Study of Maintenance Treatment With Subcutaneous Immunoglobulin (IgPro20) for Chronic Inflammatory Demyelinating Polyneuropathy (CIDP)

Multicenter, Open-label Extension Study to Investigate the Long-term Safety and Efficacy of IgPro20 in Maintenance Treatment of Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) in Subjects Completing Study IgPro20_3003

This study is an extension study to the pivotal study IgPro20_3003 (NCT01545076). The purpose of this extension study is to investigate the long-term treatment of CIDP with IgPro20, with regard to safety and efficacy.

Subjects who have completed subcutaneous (SC) Week 25 or were successfully rescued from a CIDP relapse during the SC Treatment Period of pivotal study IgPro20_3003 (NCT01545076) will have the option to receive open-label low-dose IgPro20 (0.2 g/kg bodyweight [bw]) weekly for up to 48 weeks. Subjects relapsing on low-dose IgPro20 will either return to high-dose IgPro20 (0.4 g/kg) immediately or be discontinued, depending on investigator's judgment. Subjects returning to high-dose IgPro20 will continue on high-dose until they have completed a total of 48 weeks of IgPro20 treatment. If subjects do not successfully recover from CIDP relapse within 4 weeks, they will be withdrawn.

The treatment duration will be up to 48 weeks, followed by a completion visit (week 49).

Inclusion Criteria:

• Subjects having completed the pivotal study IgPro20_3003 (SC Week 25) or successfully rescued from a CIDP relapse during the SC Treatment Period of pivotal study IgPro20_3003 (NCT01545076).
• Written informed consent for study participation obtained before undergoing any study-specific procedures.

Exclusion Criteria:

• Subject is unable to directly transition from study IgPro20_3003.
• New medical condition and/or social behavior (ie, alcohol, drug, or medication abuse) during participation in study IgPro20_3003 that in the judgment of the investigator could increase risk to the subject, interfere with the evaluation of investigational medicinal product, and/or conduct of the study.