Open-label Uncontrolled Trial to Evaluate Pharmacokinetics, Pharmacodynamics, Safety, and Activity of Efgartigimod in Children From 2 to Less Than 18 Years of Age With Generalized Myasthenia Gravis
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.
• Eligible participants should have an unsatisfactory response (efficacy and/or safety) to immunosuppressants, steroids or acetylcholinesterase (AChE) inhibitors and should be on stable concomitant gMG therapy of adequate duration before screening.
• Positive serologic test for acetylcholine receptor (anti-AChR) antibodies at screening (for younger participants (\<15kg) historical values can be used).
• Contraceptive use should be consistent with local regulations regarding the methods of contraception for those participating in clinical trials. A subject is of childbearing potential if, in the opinion of the investigator, he/she is biologically capable of having children and is sexually active.
‣ Male participants: Male participants must agree to not donate sperm from of providing informed consent/assent until they have completed the trial.
⁃ Female participants: Female adolescents of childbearing potential must have a negative serum pregnancy test at screening and a negative urine pregnancy test at baseline before investigational medicinal product (IMP) can be administered.