Primary Immune Thrombocytopenia (ITP)
Conditions
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. More information can be found here: https://clinicaltrials.argenx.com/advancenext
Interventions
BIOLOGICALEfgartigimod IV
Intravenous infusion of efgartigimod
OTHERPlacebo IV
Intravenous infusion of placebo
Sponsors
argenx
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* 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
Exclusion criteria
* 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.
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Extent of disease control, defined as the number of cumulative weeks during the 24-week Double-Blinded Treatment Period with platelet counts of at least 50 × 10^9/L | Up to 24 weeks |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| 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 | — |
| 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 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 | — |
| 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 | — |
| 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 with an IWG response during the DBTP | Up to 24 weeks | International Working Group (IWG) |
| 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 at study week 5 of the DBTP | Up to 20 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 | — |
| 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 | Up to 76 weeks | — |
| 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 | — |
| 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 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 | — |
| 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 | — |
| In participants receiving placebo IV in the DBTP, the proportion of participants achieving 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 | — |
| 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 | — |
| 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 | — |
| Occurrence rate of rescue ITP therapy | Up to 76 weeks | — |
| Proportion of participants with reduction in concurrent ITP therapy during the OLTP1 | Up to 52 weeks | — |
| Incidence and severity of bleeding, assessed by the ITP Bleeding Scale (IBLS) | Up to 76 weeks | — |
| Incidence of AEs (including AEs of clinical interest) and SAEs | Up to 136 weeks | AE = adverse event; SAE = serious adverse event; An adverse event of clinical interest is a pre-specified medically significant event that has the potential to be causally associated with the study drug. |
| Incidence of ADA against efgartigimod in serum over time | Up to 136 weeks | ADA = antidrug antibodies |
| Incidence of NAb against efgartigimod in serum over time | Up to 136 weeks | NAb = Neutralizing antibodies |
| Efgartigimod Cmax over time | Up to 136 weeks | — |
| Percent change from baseline in total IgG levels in serum over time | Up to 136 weeks | IgG = immunoglobulin G |
Countries
Austria, Bulgaria, China, Croatia, Czechia, France, Germany, Hungary, Ireland, Italy, Poland, Portugal, Romania, Serbia, Spain, United Kingdom, United States
Contacts
CONTACTSabine Coppieters, MD
Outcome results
None listed