A Study of Efgartigimod Intravenous Infusion in Children 12 to Under 18 Years with Chronic Immune Thrombocytopenia (ITP) Evaluating Pharmacokinetics and Pharmacodynamics

What this Trial Is About

Researchers are evaluating the appropriate dose of efgartigimod given by intravenous infusion for young patients aged 12 to under 18 years who have chronic immune thrombocytopenia (ITP), a condition that affects platelet counts. This study is a randomized, double-blinded, placebo-controlled trial followed by an open-label phase, designed to better understand how efgartigimod works in this pediatric population. Participants are randomly assigned in a 2:1 ratio to receive either efgartigimod IV or a placebo IV during the double-blinded treatment period lasting up to 24 weeks. After this, all participants receive efgartigimod IV during the first year of an open-label treatment period (OLTP1). Those who complete OLTP1 can continue into a second open-label treatment year (OLTP2). After OLTP2, participants enter an approximately 8-week follow-up period without the study drug, with total participation lasting up to about 138 weeks. Throughout the study, participants will undergo regular blood tests to measure efgartigimod levels and total IgG in the blood. Researchers will also monitor platelet counts, bleeding events, and immune responses to the treatment. Quality of life and fatigue will be assessed using questionnaires. Safety will be closely tracked through the study and follow-up periods. This detailed monitoring helps researchers understand the treatment's effects and long-term impact on pediatric patients with chronic ITP.

A Study of Efgartigimod IV in Participants From 12 Years to Less Than 18 Years of Age With Chronic Immune Thrombocytopenia (ITP)