ClinicalTrials.gov record NCT06831058

A Pilot Study of Efgartigimod for Immune-mediated Thrombotic Thrombocytopenic Purpura (iTTP)

Record copied from ClinicalTrials.gov: Oct 10, 2026AI summaries generated: Jul 27, 2026

A Pilot Study of Efgartigimod for Immune-mediated Thrombotic Thrombocytopenic Purpura (iTTP)

StatusRecruitingThe study is currently enrolling participants. Only the study team can say whether a particular person can join.
Study typeInterventionalA study in which researchers assign participants to one or more interventions, such as a drug, procedure, device, behavioural programme or other approach, to measure their effects.
PhasePhase 2A study that tests whether a treatment has the intended effect and continues to check safety, usually in a larger group than phase 1.
Age18 years old and older
SexAll
LocationUnited States
AI summaryWhat this study is about, in plain languageShow ▾Hide ▴

AI-written from the registry record, not the study's own wording. May contain errors or omissions. Check the registry text on this page and the original record ↗ before acting on it.

This is a Phase 2, open-label pilot study giving weekly intravenous efgartigimod to adults with immune-mediated TTP who are in clinical remission but have reduced ADAMTS13 activity. Treatment is given for 8 weeks with monitoring of ADAMTS13 and safety, followed by an 8-week observational period or until treatment failure. Outcomes will be compared with a historical group of patients treated with rituximab.

What it is studying. The study tests whether weekly IV efgartigimod can increase ADAMTS13 activity, reduce pathogenic ADAMTS13 antibodies, and evaluates safety by measuring relapse rates and adverse events compared with a historical rituximab-treated cohort.

What the researchers hope to learn. Measure safety and tolerability of efgartigimod; determine whether efgartigimod normalizes ADAMTS13 activity by Day 60; assess reduction in ADAMTS13 antibody levels; compare relapse rate and use of rescue (preemptive) therapy and the speed of ADAMTS13 activity rise with historical rituximab data.

What this study is about

The study's own summary, as published on ClinicalTrials.gov. Underlined terms have a short explanation.

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.

Interventions being studied

Being studied in this trial does not mean the treatment or procedure is approved or available for this condition.

Drug
  • efgartigimod

Eligibility

The criteria exactly as listed on ClinicalTrials.gov. Only the study team can say whether they apply to you.

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
  • 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.
  • Sexually active male subjects must agree to use an effective method of contraception for the duration of the 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

Study description and what participation involves

The registry record has no detailed description beyond the summary above.

AI summaryWhat participation may involve, in plain languageShow ▾Hide ▴

AI-written from the registry record, not the study's own wording. May contain errors or omissions. Check the registry text on this page and the original record ↗ before acting on it.

Receive weekly intravenous efgartigimod infusions with monitoring of ADAMTS13 activity during an 8‑week treatment period. Have repeated blood tests to check ADAMTS13 levels and safety, plus monitoring for adverse events. After treatment, be followed for an additional 8 weeks (or until treatment failure). Pregnancy testing and contraception requirements apply, and participants must not join other investigational drug studies during this study.

How the study is structured. An open-label, single-group Phase 2 treatment study: participants receive intravenous efgartigimod once weekly for 8 weeks, have regular laboratory and safety monitoring, then are followed for about 8 more weeks; results are compared to historical rituximab-treated patients.

Questions you could ask

These questions are suggestions for a conversation with the study team or your own clinician, not advice.

  • The listed sites are in United States. Is any of them reachable for me, and does the study help with travel?
  • Which of the eligibility criteria would need to be checked with tests before I could join?

More on thrombotic thrombocytopenic purpura

Clinical trials18 trials listed for thrombotic thrombocytopenic purpuraEvery trial the registry lists for thrombotic thrombocytopenic purpura, with recruitment status, phase and sites, updated from ClinicalTrials.gov.See all trials →Research updatesWhat changed in thrombotic thrombocytopenic purpura researchLatest monthly update: September 2026. Includes: Caplacizumab use. New research summarized each month in plain language, with links to every source paper.Read the latest update →

Important dates

Study start
May 1, 2025
Primary completion
May 1, 2028 (estimated)
Study completion
May 1, 2028 (estimated)
Target enrollment
15 participants (estimated)
Last updated on registry
Jun 11, 2026
Data verified
Oct 10, 2026

Sponsor and research team

The lead sponsor funds and oversees the trial. A pharmaceutical or biotech company sponsor typically means the study is testing that company's drug or device; a hospital, university, or government agency usually indicates investigator-initiated or publicly funded research.

Lead sponsor
University of Minnesota

Central study contact

If you're interested in participating, the central contact can answer general questions about the study — including eligibility requirements and how to find a recruiting site near you. Actual eligibility is determined by the site's medical team.

Participating sites (1)

Terms used on this page · explanations by MedicalUpdates.ai

relapse
A condition that improved with treatment and has since returned or worsened.
informed consent form
The process of explaining a study, including its risks and what participation involves, so that a person can decide freely whether to take part. Consent is usually documented in writing, and a participant can choose to leave the study later.
immunosuppressants
A medicine that reduces the activity of the immune system. Studies of autoimmune conditions often require a stable dose, a prior failure, or a washout of such medicines.
childbearing potential
Studies often ask participants who could become pregnant, or could father a child, to use contraception during the study and for a period afterwards, because the effect of the treatment on a pregnancy is unknown.
investigational product
A treatment that is being tested and has not been approved for this use. It may be approved for a different condition. Being studied does not mean it works or is available outside the study.
enrollment
The number of participants a study plans to include, or has included. 'Estimated' means the planned number; 'actual' means the number who joined.
Inclusion Criteria
The conditions a person must meet to be considered for the study, for example a confirmed diagnosis, an age range or a test result.
Exclusion Criteria
The conditions that rule a person out even if they meet the inclusion criteria, for example other illnesses, certain medicines or pregnancy.

The study record on this page is reproduced from ClinicalTrials.gov, a database of the U.S. National Library of Medicine, where it was submitted by the study sponsor. MedicalUpdates.ai does not own this content, is not affiliated with or endorsed by ClinicalTrials.gov, NIH, or the U.S. Government, and does not verify the record. Plain-language notes, the glossary and the questions above are added by this site; text in the boxes marked "AI summary" was written by an AI model and may contain errors. Registry records change over time. Check the original record for the current version and discuss eligibility or participation with a qualified healthcare professional.

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