Open Label Extension of Efgartigimod in Adults With Post-COVID-19 POTS

Open-Label Extension Study to Evaluate the Long-term Safety and Efficacy of Efgartigimod in Adult Patients With Post-COVID-19 Postural Orthostatic Tachycardia Syndrome (PC-POTS) Who Completed Study ARGX-113-2104

The OLE study aims to investigate the safety, efficacy, pharmacodynamics (PD), pharmacokinetics (PK), and immunogenicity of efgartigimod in participants with post-COVID-19 postural orthostatic.

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.

Inclusion Criteria:

1. The participant has completed the ARGX-113-2104 study without permanent discontinuation of IMP and agrees to directly roll over into the extension study without discontinuation of IMP.
2. The participant signs the informed consent form, and can comply with OLE study (ARGX-113-2105) protocol requirements.
3. The participant agrees to use contraceptives consistent with local regulations regarding the methods of contraception for those participating in clinical studies. Contraceptive requirements are provided.
4. Female participants of childbearing potential must have a negative urine pregnancy test at baseline before receiving IMP.

Exclusion Criteria:

1. The participant has a clinically significant condition, based on the judgement of the Study Investigator, eg, laboratory abnormalities, 12-lead ECG readings, concomitant medical disease(s), etc., which may place them at undue risk or confound interpretation of study data.
2. The participant intends to become pregnant or start breastfeeding during the study.