- Study participant with severe weakness affecting oropharyngeal or respiratory muscles, or who has myasthenic crisis or impending crisis at Screening or Baseline - Study participant has a known hypersensitivity to any components of the Investigational Medicinal Product (IMP) or other anti-neonatal-Fc receptor (FcRn) medications - Study participant with any active or untreated thymoma - Study participant has a history of thymectomy within 6 months prior to Screening - Study participant has a clinically relevant active infection (eg, sepsis, pneumonia, or abscess) in the opinion of the Investigator, or had a serious infection (resulting in hospitalization or requiring parenteral antibiotic treatment) within 6 weeks prior to the first dose of IMP - Study participant has received a live vaccination within 4 weeks prior to Baseline or intends to have a live vaccination during the course of the study