The purpose of this trial is to investigate the PK, PD, safety, and activity of efgartigimod IV in children and adolescents aged from 2 to less than 18 years of age with gMG.
Trial details include:
* The maximum trial duration for each individual participant will be approximately 28 weeks * The treatment duration will be 8 weeks for the dose-confirmatory part (Part A) and 18 weeks for the treatment response-confirmatory part (Part B)
Ability of the participant and/or his/her legally authorized representative to understand the requirements of the trial and provide written informed consent/assent, if applicable (including consent/assent for the use and disclosure of research-related health information), willingness and ability to comply with the trial protocol procedures (including attending the required trial visits).
Male or female participants between 2 to less than 18 years of age at the time of providing informed consent/assent. Age groups are enrolled in a staggered fashion respectively: 6 participants in the 12 to less than 18 years of age group followed by 6 participants in the 2 to less than 12 years of age group at the time of providing informed consent/assent.
Diagnosed with Generalized Myasthenia Gravis (gMG) with confirmed documentation
Meeting the clinical criteria as defined by the Myasthenia Gravis Foundation of America (MGFA) class II, III, and IVa.
Participants with MGFA class I, IVb, and V.
Female adolescents of childbearing potential: Pregnancy or lactation, or the participant intends to become pregnant during the trial or within 90 days after the last dose of IMP.
Clinically significant uncontrolled active or chronic bacterial, viral, or fungal infection at screening.
Any other known autoimmune disease that, in the opinion of the investigator, would interfere with an accurate assessment of clinical symptoms of myasthenia gravis or put the participant at undue risk.
Single group
Efgartigimod IV
Biological/VaccineIntravenous infusion of Efgartigimod
Efgartigimod concentrations as input for compartmental, model-driven analysis to determine (age and size dependency of) Clearance (CL)
Blood samples will be collected from each participant for measurement of serum concentrations of efgartigimod
Efgartigimod concentrations as input for compartmental, model-driven analysis to determine (age and size dependency of) Volume of Distribution (Vd)
Blood samples will be collected from each participant for measurement of serum concentrations of efgartigimod
Total Immunoglobulin G (IgG) levels as input for pharmacokinetics (PK) and pharmacodynamics (PD) modeling analysis
Total Immunoglobulin G levels will be measured from blood samples
Anti-acetylcholine receptors antibodies (AChR-Ab) as input for pharmacokinetics (PK) and pharmacodynamics (PD) modeling analysis
Total Immunoglobulin G (IgG) levels will be measured from blood samples
Incidence and severity of adverse events (AEs), serious adverse events (SAEs) and adverse events of special interest (AESIs)
Efgartigimod serum concentrations from blood samples
Absolute values of levels of total Immunoglobulin G (IgG) from blood samples
Change from baseline of levels of total Immunoglobulin G (IgG) from blood samples
