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

NCT07194850 | Recruiting Phase 2 DMC FDA Drug

• 2 other identifiers: ARGX-113-24092025-521055-23-00
• Study Type: interventional
• Target: 24
• Locations: 5 countries
• Sites: 8

Brief Summary

The main purpose of this study is to confirm the correct dose of efgartigimod IV for treating patients aged 12 to younger than 18 years with chronic immune thrombocytopenia (ITP). The study consists of a double-blinded treatment period (DBTP) in which the participants will be randomized in a 2:1 ratio to receive either efgartigimod IV or placebo IV. At the end of the treatment period (up to 24 weeks), all participants will receive efgartigimod IV during the first year open-label treatment period (OLTP1). At the end of the first OLTP1, participants may begin a second year (OLTP2). After the OLTP2, the participants will enter a follow-up period (approximately 8 weeks) while off study drug. The participants will be in the study for up to 138 weeks. More information can be found here: https://clinicaltrials.argenx.com/advancejunior

Conditions

Immune Thrombocytopenia (ITP); ITP - Immune Thrombocytopenia; ITP; Immune Thrombocytopenic Purpura; Immune Thrombocytopenic Purpura ( ITP ); Idiopathic Thrombocytopenic Purpura; Idiopathic Thrombocytopenic Purpura (ITP)

Outcome Measures

Primary Outcomes (2)

• Efgartigimod serum concentrations in the DBTP

  Up to 24 weeks

• Total IgG levels in the DBTP

  Up to 24 weeks

Secondary Outcomes (11)

• Efgartigimod serum concentrations over time during the DBTP

  Up to 24 weeks

• Percent change from baseline in total IgG levels in serum over time during the DBTP

  Up to 24 weeks

• Incidence of AEs, SAEs and AEs leading to IMP discontinuation

  Up to 136 weeks

• Sustained platelet count response between study weeks 19 and 24 of the DBTP and in OLTP1 for participants receiving placebo in the DBTP

  Up to 48 weeks

• Extent of disease control during the DBTP and during the first 24 weeks of OLTP1 for those participants receiving placebo in the DBTP

  Up to 48 weeks

Study Arms (2)

Efgartigimod IV

EXPERIMENTAL

Participants receiving efgartigimod IV during the double-blinded treatment period and the open-label treatment period(s)

Biological: Efgartigimod IV

Placebo IV

PLACEBO COMPARATOR

Participants receiving placebo IV during the double-blinded treatment period and receiving efgartigimod IV during the open-label treatment period(s)

Biological: Efgartigimod IV; Other: Placebo IV

Interventions

Efgartigimod IV BIOLOGICAL

Intravenous infusion of efgartigimod

Efgartigimod IV; Placebo IV

Placebo IV OTHER

Intravenous infusion of placebo

Placebo IV

Eligibility Criteria

• Age: 12 Years - 17 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17)

You may qualify if:

• Is aged 12 to less than 18 years when completing the informed consent process
• Has a documented duration of primary ITP of more than 12 months on the date the informed consent process is complete
• Has documented prior ITP treatment with at least 1 of the following treatments: corticosteroids, IVIg, anti-D immunoglobulin, thrombopoietin receptor agonist (TPO-RAs), or rituximab.
• Has documented prior response, defined as 1 platelet count of ≥50 × 10\^9/L to at least 1 of the following ITP treatments: prednisone, other or nonspecified corticosteroids, IVIg, or anti-D immunoglobulin
• Has documented insufficient response to a prior ITP treatment with corticosteroids, IVIg, anti-D immunoglobulin, TPO-RAs, rituximab, or splenectomy
• Has documented mean platelet count of less than 30 x10\^9/L

You may not qualify if:

• Secondary ITP according to the following definition by the International Working Group (IWG): all forms of immune-mediated thrombocytopenia except primary ITP
• Nonimmune thrombocytopenia
• ITP-associated critical or severe bleeding
• History of hereditary thrombocytopenia

Sponsors & Collaborators

• argenx: lead

Study Sites (8)

Gaslini Children's Hospital

Genoa, 16147, Italy

RECRUITING

Uniwersytecki Szpital Dzieciecy w Lublinie

Lublin, 20-093, Poland

RECRUITING

Institutul Clinic Fundeni

Bucharest, 022328, Romania

RECRUITING

Hospital Universitari Vall d'Hebron

Barcelona, 08035, Spain

RECRUITING

Hospital Sant Joan de Deu Barcelona

Esplugues de Llobregat, 08950, Spain

RECRUITING

Hospital Infantil Universitario Nino Jesus (HIUNJS)

Madrid, 28009, Spain

RECRUITING

Hospital Materno-Infantil Universitario Gregorio Maranon

Madrid, 28009, Spain

RECRUITING

Cardiff and Vale NHS Trust - University Hospital of Wales (UHW)

Cardiff, CF14 4XW, United Kingdom

RECRUITING

Related Links

• Study website

MeSH Terms

Conditions

Purpura, Thrombocytopenic, Idiopathic

Condition Hierarchy (Ancestors)

Purpura, Thrombocytopenic; Purpura; Blood Coagulation Disorders; Hematologic Diseases; Hemic and Lymphatic Diseases; Thrombotic Microangiopathies; Thrombocytopenia; Blood Platelet Disorders; Cytopenia; Hemorrhagic Disorders; Autoimmune Diseases; Immune System Diseases; Hemorrhage; Pathologic Processes; Pathological Conditions, Signs and Symptoms; Skin Manifestations; Signs and Symptoms

Central Study Contacts

Sabine Coppieters, MD

CONTACT

857-350-4834; clinicaltrials@argenx.com

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: RANDOMIZED
• Masking: QUADRUPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: September 19, 2025
• First Posted: September 26, 2025
• Study Start: October 20, 2025
• Primary Completion (Estimated): October 1, 2028
• Study Completion (Estimated): October 1, 2030
• Last Updated: April 20, 2026

Record last verified: 2026-04

Data Sharing

• IPD Sharing: Will not share

Locations

ES (4); RO (1); IT (1); GB (1); PL (1)