Immune Thrombocytopenia (ITP) is a rare, serious autoimmune disease that can worsen over time. ITP occurs when the immune system mistakenly attacks and destroys the blood-clotting cells in the body (called platelets). Bleeding can occur when platelet levels are low in the blood. If the platelet count is very low, the bleeding can be serious. Bleeding can occur from the skin, brain, and other body parts. If ITP lasts for 12 months or more after the doctor first tells you that you have ITP, it’s called chronic ITP.

The Advance Junior study is designed to evaluate how the investigational study drug* may work (also known as efficacy) and how safe it is for the use in children living with chronic ITP. The study will evaluate the investigational study drug compared to a placebo.

*The investigational study drug, efgartigimod, is not approved by any regulatory agency for use in pediatric patients living with chronic ITP as efficacy and safety have not been established. 

A child may be eligible to participate if they: 

• Are between the ages of 12 and 18
• Have ITP and have had it for more than 12 months
• Have received prior ITP treatments

For the first 24 weeks of treatment, the study will compare the investigational study drug to a placebo. Later in the study, all participants will take the active study drug.

This study has 4 phases:

• Screening (up to 2 weeks): To see if the participant meets the requirements to take part in the study.
• Double-blinded treatment phase (24 weeks):
  • Participant will receive infusions once weekly or every other week of either the study drug or placebo.
  • Treatments are given through an IV in your arm (intravenously).
  • Two out of 3 participants will receive the study drug, and 1 out of 3 will receive placebo. 
• Follow-up phase (8 weeks): There will be a final study visit 8 weeks after the last dose of the study drug to check on participants health.

Study participants who completed the Advance Junior may choose to enroll in the open label extension safety study, where the study participant will receive the investigational study drug and continue to be monitored for safety.