Objective:

Characterize the pharmacokinetics (PK), pharmacodynamics (PD), efficacy, safety, and immunogenicity of intravenous ravulizumab in pediatric patients with anti-acetylcholine receptor antibody-positive (AChR-Ab+) generalized myasthenia gravis (gMG).

Background:

gMG is a rare, chronic autoimmune disorder characterized by impaired neuromuscular transmission and fatigable muscle weakness. In patients with AChR-Ab+ gMG, the neuromuscular junction is damaged by complement activation by anti-AChR antibodies. Ravulizumab is a complement component 5 (C5) inhibitor approved in the United States, European Union, and Japan for adults with AChR-Ab+ gMG. Ravulizumab has demonstrated immediate, complete, and sustained inhibition of terminal complement and is approved for adults with AChR-Ab+ gMG. Immune-specific treatments for children with AChR-Ab+ gMG are limited. We present the design of a study of the investigational drug, ravulizumab, in children with this disease.

Design/Methods:

This phase 3, open-label, single-arm study (NCT05644561) is enrolling ~ 12 patients aged 6 to < 18 years with AChR-Ab+ gMG from 8 countries globally to receive weight-based loading (day 1) and maintenance (day 15 and every 8 weeks [4 weeks if body weight < 20 kg] thereafter) ravulizumab doses. Eligible patients may be either naive to or experienced with complement inhibitors at screening. The study comprises a 4-week screening period, an 18-week primary evaluation period, and an extension period of up to 108 weeks. Primary outcomes will assess PK and PD using concentration data for serum ravulizumab and serum free C5 from day 1 pre-dose to week 18 pre-dose. Secondary outcomes will assess efficacy, quality of life, safety, and immunogenicity.

Results:

N/A

Conclusions:

This study will examine ravulizumab treatment in pediatric patients with AChR-Ab+ gMG.