Randomization and masking
Randomization within the double‐blind phase was performed using an interactive web response system with central randomization. Patients were randomly assigned (1:1:1) to receive batoclimab 680 mg/week (two syringes each containing 2 mL study drug), batoclimab 340 mg/week (one syringe containing 2 mL study drug and 1 syringe containing 2 mL matched placebo), or placebo alone (two syringes each containing 2 mL matched placebo). The same formulation was used for matched placebo as for batoclimab, but without the active ingredient. An unblinded medical monitor reviewed IgG, albumin, total protein, alkaline phosphatase, and anti‐AChR antibody data after screening on an ongoing basis for safety. However, to maintain blinding, investigators, study site personnel, and patients remained blinded to these data throughout both the double‐blind phase and OLE study.