Efficacy, Safety, Pharmacokinetics, Pharmacodynamics, and Immunogenicity of Eculizumab in Chinese Adults With gMG

This post-approval study is an open-label, single-arm, multi-center study to evaluate the efficacy, safety, PK, PD, and immunogenicity of eculizumab in Chinese participants with refractory gMG. There will be 3 periods in this study: Screening Period (up to 4 weeks), Treatment Period (26 weeks, including an Induction Phase and a Maintenance Phase), and Safety Follow-up Period (8 weeks). The overall study duration for an individual participant is estimated to be up to 38 weeks. Approximately 15 participants will be enrolled in the study.

Inclusion criteria

• Diagnosis of MG must be made by the following tests:

• Positive serologic test for anti-AChR Abs as confirmed at Screening, and
• One of the following:

• Abnormal neuromuscular transmission demonstrated by repetitive nerve stimulation, or
• History of positive anticholinesterase test, eg, neostigmine test, or
• Participant has demonstrated improvement in MG signs on oral cholinesterase inhibitors as assessed by the treating physician
• MGFA Clinical Classification Class II to IV at Screening
• MG-ADL total score must be ≥ 6 at Screening and Day 1
• Participants who have:

• Failed treatment with 2 or more ISTs over one year (either in combination or as monotherapy), ie, continue to have impairment ADLs (persistent weakness, experience crisis, or unable to tolerate IST) despite ISTs or,
• Failed at least one IST and require chronic PE or IVIg to control symptoms, ie, participants who require PE or IVIg on a regular basis for the management of muscle weakness at least 2 cycles over last 12 months

Exclusion criteria

• Any untreated thymic malignancy, carcinoma, or thymoma
• History of thymectomy or any other thymic surgery within 6 months prior to Screening. Participants with a history of treated thymic malignancy or carcinoma are eligible if they meet all of the following conditions:

• Treatment completed > 5 years prior to the Screening Visit
• No recurrence within the 5 years prior to the Screening Visit
• No radiological indication of recurrence in a computed tomography (CT) or magnetic resonance imaging (MRI) scan, including administration of intravenous (IV) contrast, performed within 6 months of first dose on Day 1
• Weakness only affecting ocular or peri-ocular muscles (MGFA Class I)
• MG crisis at Screening (MGFA Class V). However, such participants may be rescreened with Alexion approval once they are treated and medically stable, in the opinion of the Investigator
• History of N meningitidis infection or unresolved meningococcal disease