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

argenx

Status and phase: Enrolling; Phase 3; Phase 2

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

Treatments: Biological: Efgartigimod IV; Other: Placebo IV

Study type: Interventional

Funder types: Industry

Identifiers

NCT07194850

ARGX-113-2409

2025-521055-23-00 (EU Trial (CTIS) Number)

Details and patient eligibility

About

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

Enrollment: 24 estimated patients

Sex: All

Ages: 12 to 17 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• 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

Exclusion criteria

• 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

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Quadruple Blind

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24 participants in 2 patient groups, including a placebo group

Efgartigimod IV

Experimental group

Description:

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

Treatment:

Biological: Efgartigimod IV

Placebo IV

Placebo Comparator group

Description:

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

Treatment:

Other: Placebo IV

Biological: Efgartigimod IV