Immune-mediated Thrombotic Thrombocytopenic PurpuraPhase 2NCT06831058
A Pilot Study of Efgartigimod for Immune-mediated Thrombotic Thrombocytopenic Purpura (iTTP)
A Phase 2 study testing efgartigimod in people with Immune-mediated Thrombotic Thrombocytopenic Purpura, run by University of Minnesota at 1 site in United States.
Trial 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. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Immune-mediated Thrombotic Thrombocytopenic Purpura
- What is being tested?
- efgartigimod
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 15 participants
- Where
- 1 siteUnited States
- Study dates
- 1 May 2025to 1 May 2028
- Phase
- Phase 2
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- 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
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- 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
Who cannot join
- 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
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
University of Minnesota
Minneapolis, Minnesota, 55455
Diondra Howard, 651-208-7476, howar709@umn.edu
About this study
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.
- Being tested
- efgartigimod
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
efgartigimodDrug
intravenous efgartigimod weekly with monitoring of ADAMTS13 activity for 8 weeks, followed by an observational period of 8 weeks or until treatment failure.
| Study group | Role | What they receive |
|---|---|---|
| iTTP patients | Experimental | participants with a history of iTTP in clinical remission but with ADAMTS13 deficiency (>30% but < 70% activity) Receives: Drug: efgartigimod |
What is being measured
The primary outcome is the main question the study is designed to answer.
safety of efgartigimod by the incidence of relapse
Relapse rate in the experimental arm compared with the historical rituximab arm
Measured: 8 weeks post-intervention
safety and tolerability of efgartigimodhistorical rituximab arm
Incidence and severity of adverse events (AEs), AEs of special interest (AESIs) and serious AEs (SEAs)
Measured: 8 weeks post-intervention
efficacy of efgartigimod to achieve a normal ADAMTS13 activity by Day 60 of the study
Compare the mean ADAMTS13 activity and proportion with normal ADAMTS13 activity at Day 60 and 90 between the experimental and historical cohorts
Measured: 60 days
efficacy of efgartigimod to prevent the need for other preemptive therapy to rescue severe ADAMTS13 deficiency
Compare the rate use of rescue therapy between the experimental and historical cohort treated with preemptive rituximab, as required by the lack of ADAMTS13 activity increase by 20%
Measured: 8 weeks post-intervention
Secondary outcomes (2)
the efficacy of efgartigimod to raise ADAMTS13 activity more rapidly than historically treated patients with rituximab
Compare the mean slope of ADAMTS13 rise at the end of treatment (Day 60) and at 90 days between cohorts
Measured: Day 60 and day 90
the efficacy of efgartigimod to deplete pathogenic ADAMTS13 antibodies
Compare the mean ADAMTS13 antibody titers and proportion with >50% reduction in antibody titer between cohorts
Measured: 8 weeks post-intervention
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted17 Feb 2025
- Study start1 May 2025
- Primary completion1 May 2028 (estimated)
- Study completion1 May 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Immune-mediated Thrombotic Thrombocytopenic PurpuraStudies of the same condition, open and under way.
- More trials run by University of MinnesotaThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 2
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 15 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Minnesota
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Marshall Mazepa, MD, Principal investigator, University of Minnesota
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06831058
- Sponsor's protocol ID
- HOT-2024-32825
- Status last verified
- Jun 2026
- First submitted
- 13 Feb 2025
- Last updated
- 11 Jun 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 11 Jun 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Pilot Study of Efgartigimod for Immune-mediated Thrombotic Thrombocytopenic Purpura (iTTP)
- ClinicalTrials.gov ID
- NCT06831058
- Acronym / sponsor ID
- HOT-2024-32825
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 15 participants (estimated)
- Lead sponsor
- University of MinnesotaUniversity, hospital or other
- Study start
- 1 May 2025 (actual)
- Primary completion
- 1 May 2028 (estimated)
- Study completion
- 1 May 2028 (estimated)
- First posted
- 17 Feb 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| iTTP patients | Experimental | Drug: efgartigimodparticipants with a history of iTTP in clinical remission but with ADAMTS13 deficiency (>30% but < 70% activity) |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (9 listed)
- 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
Key exclusion criteria (5 listed)
- 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
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| efgartigimodintravenous efgartigimod weekly with monitoring of ADAMTS13 activity for 8 weeks, followed by an observational period of 8 weeks or until treatment failure. | Drug | iTTP patients |
Primary outcome
safety of efgartigimod by the incidence of relapse
Time frame: 8 weeks post-intervention
Relapse rate in the experimental arm compared with the historical rituximab arm
safety and tolerability of efgartigimodhistorical rituximab arm
Time frame: 8 weeks post-intervention
Incidence and severity of adverse events (AEs), AEs of special interest (AESIs) and serious AEs (SEAs)
efficacy of efgartigimod to achieve a normal ADAMTS13 activity by Day 60 of the study
Time frame: 60 days
Compare the mean ADAMTS13 activity and proportion with normal ADAMTS13 activity at Day 60 and 90 between the experimental and historical cohorts
efficacy of efgartigimod to prevent the need for other preemptive therapy to rescue severe ADAMTS13 deficiency
Time frame: 8 weeks post-intervention
Compare the rate use of rescue therapy between the experimental and historical cohort treated with preemptive rituximab, as required by the lack of ADAMTS13 activity increase by 20%
2 secondary outcomes
the efficacy of efgartigimod to raise ADAMTS13 activity more rapidly than historically treated patients with rituximab
Time frame: Day 60 and day 90
the efficacy of efgartigimod to deplete pathogenic ADAMTS13 antibodies
Time frame: 8 weeks post-intervention
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 11 Jun 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Marshall Mazepa, MD principal investigator
University of Minnesota
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing efgartigimod in people with Immune-mediated Thrombotic Thrombocytopenic Purpura, run by University of Minnesota at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 9 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 11 Jun 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Diondra Howard (651-208-7476, howar709@umn.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
safety of efgartigimod by the incidence of relapse (time frame: 8 weeks post-intervention). The study lists 4 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 11 Jun 2026.