A Study to Assess the Efficacy and Safety of Efgartigimod IV in Adult Participants With Primary Immune Thrombocytopenia
- Conditions
- Primary Immune Thrombocytopenia (ITP)
- Interventions
- Biological: Efgartigimod IVOther: Placebo IV
- Registration Number
- NCT06544499
- Lead Sponsor
- argenx
- Brief Summary
The main purpose of this study is to look at the effect (efficacy) and safety of efgartigimod IV in participants with primary immune thrombocytopenia (ITP). After an up to 2 weeks screening period, eligible participants will be randomized in a 2:1 ratio to receive either efgartigimod IV or placebo IV, respectively during the double-blinded treatment period (DBTP). At the end of the treatment period (up to 24 weeks), all participants will receive efgartigimod IV during the first 52-week open-label treatment period (OLTP1). At the end of the first OLTP1, participants may begin a second 52-week 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.
- Detailed Description
Not available
Recruitment & Eligibility
- Status
- RECRUITING
- Sex
- All
- Target Recruitment
- 63
- Is at least 18 years of age and the local legal age of consent for clinical studies when signing the informed consent form (ICF).
- Has documented baseline mean platelet count of <30 x 10^9/L before randomization
- Has a documented duration of primary immune thrombocytopenia (ITP) of more than 12 months on the date of informed consent form (ICF) signature.
- Has documented prior ITP treatment with at least 1 of the following treatments: corticosteroids, intravenous immunoglobulin (IVIg), anti-D immunoglobulin, thrombopoietin receptor agonist (TPO-RAs), or rituximab.
- Has documented insufficient response to a prior ITP treatment (the specific criteria can be found in the protocol).
- Has documented prior response defined as 1 platelet count of ≥50 × 109/L to at least 1 of the following ITP treatments in the 3 years before the date of ICF signature: prednisone, dexamethasone, other or nonspecified corticosteroids, IVIg, or anti-D immunoglobulin
- Other than the indication under study, known autoimmune disease or any medical condition that would interfere with an accurate assessment of clinical symptoms of ITP, confound the results of the study or put the participant at undue risk.
- Secondary ITP
- Nonimmune thrombocytopenia
- Autoimmune hemolytic anemia
- ITP-associated critical or severe bleeding The complete list of criteria can be found in the protocol.
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- PARALLEL
- Arm && Interventions
Group Intervention Description Efgartigimod IV Efgartigimod IV Participants receiving efgartigimod IV during the double-blinded treatment period and the open-label treatment period(s) Placebo IV Efgartigimod IV Participants receiving placebo IV during the double-blinded treatment period and receiving efgartigimod IV during the open-label treatment period(s) Placebo IV Placebo IV Participants receiving placebo IV during the double-blinded treatment period and receiving efgartigimod IV during the open-label treatment period(s)
- Primary Outcome Measures
Name Time Method Extent of disease control, defined as the number of cumulative weeks during the Double-Blinded Treatment Period with platelet counts of at least 50 × 10^9/L Up to 24 weeks
- Secondary Outcome Measures
Name Time Method Proportion of participants achieving a platelet count of at least 50 × 10^9/L on at least 4 occasions at any time until study week 12 during the DBTP Up to 12 weeks Proportion of participants achieving platelet counts of at least 50 × 10^9/L for at least 4 of the 6 study visits between study weeks 19 and 24 of the DBTP Up to 6 weeks Time to response, defined as the time to achieve 2 consecutive platelet counts of at least 50 × 10^9/L at any time during the DBTP up to 24 weeks Proportion of participants achieving a platelet counts of at least 50 × 10^9/L for at least 8 of the 12 study visits between weeks 13 and 24 of the DBTP Up to 12 weeks Extent of disease control, defined as the number of cumulative weeks with platelet counts of at least 50 × 10^9/L Up to 76 weeks Proportion of participants achieving platelet counts of at least 50 × 10^9/L for at least 6 of the 8 study visits between study weeks 17 and 24 of the DBTP Up to 8 weeks Proportion of participants with an IWG response during the DBTP Up to 24 weeks International Working Group (IWG)
Overall platelet count response, defined as the proportion of participants achieving a platelet count of at least 50 × 10^9/L on at least 4 occasions during the first 52 weeks of treatment with efgartigimod IV Up to 52 weeks Mean change from baseline in platelet count at each study visit Up to 76 weeks Proportion of participants who achieve a sustained platelet count response, defined as achieving platelet counts of at least 50 × 10^9/L for at least 4 occasions during 6-week intervals Up to 76 weeks Proportion of participants achieving a platelet counts of at least 50 × 10^9/L for at least 8 of the 12 study visits between weeks 13 and 24 of the OLTP1 Up to 12 weeks Proportion of participants with reduction in concurrent ITP therapy during the OLTP1 Up to 52 weeks Incidence of antidrug antibodies (ADA) against efgartigimod in serum over time Up to 136 weeks Incidence of NAb against efgartigimod in serum over time Up to 136 weeks Proportion of participants with initial response, defined as a platelet count of at least 30 × 10^9/L and a 2-fold increase from baseline in platelet count from study week 5 of the DBTP Up to 20 weeks In participants with baseline platelet counts <15 × 10^9/L, the percentage of weeks with platelet counts of at least 30 × 10^9/L and at least 20 × 10^9/L above baseline Up to 76 weeks In participants receiving placebo IV in the DBTP, proportion of participants who achieve sustained platelet count response, defined as achieving platelet counts of at least 50 × 10^9/L for at least 6 of 8 visits between weeks 17 and 24 of the OLTP1 Up to 8 weeks Occurrence rate of rescue ITP therapy Up to 76 weeks Incidence and severity of bleeding, assessed by the ITP Bleeding Scale (IBLS) Up to 76 weeks Time to achieve a platelet count of at least 30 × 10^9/L and a 2-fold increase from baseline in platelet count during the DBTP Up to 24 weeks The percentage of weeks with platelet counts of at least 30 × 10^9/L and at least 20 × 10^9/L above baseline Up to 76 weeks Number of cumulative weeks during the DBTP with platelet counts of at least 30 × 10^9/L and ≥20 × 10^9/L above baseline Up to 24 weeks Number of cumulative weeks during the DBTP with platelet counts of at least 30 × 10^9/L and at least 20 × 10^9/L above baseline in participants with baseline platelet counts of <15 × 10^9/L Up to 24 weeks Extent of disease control, defined as the percentage of weeks with platelet counts of at least 50 × 10^9/L Up to 76 weeks In participants receiving placebo IV in the DBTP, the extent of disease control, defined as the number of cumulative weeks with platelet counts of at least 50 × 10^9/L during the first 24 weeks of treatment with efgartigimod IV Up to 24 weeks Percent change from baseline in total IgG levels in serum over time Up to 136 weeks Incidence of AEs of clinical interest Up to 136 weeks Efgartigimod Cmax over time Up to 136 weeks
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Trial Locations
- Locations (23)
University of Southern California Norris Comprehensive Cancer Center
🇺🇸Los Angeles, California, United States
Krankenhaus der Elisabethinen Linz GmbH
🇦🇹Linz, Austria
St James's Hospital - Cancer Clinical Trials Office
🇮🇪Dublin, Ireland
Azienda ULSS 7 Pedemontana
🇮🇹Bassano del Grappa, Italy
Universita Degli Studi Di Firenze - Azienda Ospedaliero-Universitaria Careggi (AOUC)
🇮🇹Firenze, Italy
AO Maggiore Della Carita
🇮🇹Novara, Italy
U.O.C. Ematologia Ospedale Santa Maria delle Croci
🇮🇹Ravenna, Italy
AO Ordine Mauriziano di Torino
🇮🇹Torino, Italy
Azienda Sanitaria Universitaria Integrata
🇮🇹Trieste, Italy
Pratia Onkologia Katowice
🇵🇱Katowice, Poland
Complejo Hospitalario Universitario A Coruna
🇪🇸La Coruna, Spain
University Hospitals Coventry and Warwickshire NHS Trust
🇬🇧Coventry, United Kingdom
Glasgow Royal Infirmary - North Glasgow University Hospital Division
🇬🇧Glasgow, United Kingdom
Barts and the London Pathology & Pharmacy Building - Barts Health NHS Trust
🇬🇧London, United Kingdom
Hammersmith Hospital, Imperial College School Of Medicine - Imperial College Healthcare NHS Trust
🇬🇧London, United Kingdom
Royal Cornwall Hospital (RCH)
🇬🇧Truro, United Kingdom
Regional Cancer Care Associates, LLC (RCCA)
🇺🇸Little Silver, New Jersey, United States
Clinical Research Alliance Inc.
🇺🇸Westbury, New York, United States
University Hospital Prof. Dr. Stoyan Kirkovich AD
🇧🇬Stara Zagora, Bulgaria
Hospital Universitario Ramon y Cajal
🇪🇸Madrid, Spain
Hospital General Universitario Morales Meseguer
🇪🇸Murcia, Spain
University Hospital Quironsalud Madrid
🇪🇸Pozuelo de Alarcon, Spain
Hospital Clinico Universitario - University of Valencia
🇪🇸Valencia, Spain