A Pilot Study of Efgartigimod for Immune-mediated Thrombotic Thrombocytopenic Purpura (iTTP) (NCT06831058) | Clinical Trial Compass
RecruitingPhase 2
A Pilot Study of Efgartigimod for Immune-mediated Thrombotic Thrombocytopenic Purpura (iTTP)
United States15 participantsStarted 2025-05-01
Plain-language summary
Immune-mediated Thrombotic thrombocytopenic purpura (iTTP) is a rare, autoimmune disorder characterized by life-threatening episodes of thrombocytopenia, microangiopathic hemolytic anemia and organ damage. Patients have an unpredictable course punctuated by relapses associated with autoantibody-mediated (primarily IgG) depletion of ADAMTS13, a key regulator of coagulation. ADAMTS13 deficiency during remission has been associated with increased risk of relapse, but also, and potentially more devastating, ischemic stroke.
Until recently, it was presumed that rituximab (a monoclonal antibody targeting B cells) improved relapse-free survival in most patients, but this was based on findings from very small studies. Given concern about stroke and relapse risk, preventive immunosuppression with rituximab has also recently come into practice for patients with falling ADAMTS13 activity (ADAMTS13-relapse). It is expected that following efgartigimod therapy, there will be a rise in ADAMTS13 activity to the normal range that will be sustained during the treatment period. Following withdrawal of therapy, it is expected that most participants will experience a fall in ADAMTS13 activity, demonstrating the safety and efficacy in efgartigimod to reliably but temporarily reduce pathogenic antibodies. This would demonstrate the potential efficacy for efgartigimod as a maintenance therapy to safely prevent relapse of iTTP to be further explored in a larger efficacy study.
Who can participate
Age range
18 Years
Sex
ALL
See this in plain English?
AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
Inclusion criteria
. Subject must provide a signed informed consent form
. Subject is 18 years or older at the time of screening
. Subject has a prior history of iTTP as defined by the presence of ADAMTS13 activity \< 10% with ADAMTS13 antibodies or inhibitor, thrombocytopenia (platelet count \< 100) and microangiopathic hemolytic anemia (defined by the presence of schistocytes on blood smear)
. Subject is in clinical remission from iTTP (normal platelet count) for at least 90 days
. Subject has ADAMTS13 activity \< 70% and \> 30% on 2 separate occasions separate by at least 7 days
. Subject is at least 6 months from last dose of rituximab or other intravenous immunosuppression
Questions worth asking your doctor
Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.
1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?
Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.
Questions for the trial coordinator
The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.
1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?
A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.
What they're measuring
1
safety of efgartigimod by the incidence of relapse
Timeframe: 8 weeks post-intervention
2
safety and tolerability of efgartigimodhistorical rituximab arm
Timeframe: 8 weeks post-intervention
3
efficacy of efgartigimod to achieve a normal ADAMTS13 activity by Day 60 of the study
Timeframe: 60 days
4
efficacy of efgartigimod to prevent the need for other preemptive therapy to rescue severe ADAMTS13 deficiency
. If taking other oral immunosuppressants, no change in dose for at least 60 days
. Female subjects of childbearing potential must present with a negative pregnancy test and agree to employ highly effective birth control measures for duration of study.
Exclusion criteria
. Subject has been diagnosed with cTTP
. Subject has been exposed to another investigational product within 30 days prior to enrollment or is scheduled to participate in another clinical study involving investigational product or investigational device during the course of the study
. Subject is unable to understand the nature, scope, and possible consequences of the study.
. Subject is pregnant or lactating
. Subject has a known life-threatening hypersensitivity reaction to efgartigimod