Study ARGX-113-2105 is a long-term, single-arm, open-label, multicenter extension of the ARGX-113-2104 study, designed to evaluate the long-term safety of efgartigimod IV in adult patients with PC-POTS. Participants will be enrolled from both active and placebo arms of the ARGX-113-2104 study and will receive efgartigimod IV 10 mg/kg in the extension study without knowledge of their prior treatment arm. To be eligible to enroll in this study, participants must have completed the 24-week treatment period of the ARGX-113-2104 study and must not have permanently discontinued the IMP in that study.
