Who may be eligible for the Aspirin for Prophylaxis of TTP trial?

Inclusion Criteria: 1. Those who voluntarily signed the informed consent form and were able to comply with the study protocol. 2. Subjects diagnosed with severe ADAMTS13 deficiency, defined as ADAMTS13 activity \<10%, documented in the patient's medical history or at screening. Note: In patients receiving fresh frozen plasma (FFP) or other prophylactic treatments containing ADAMTS13 products, plasma ADAMTS13 activity levels at screening may exceed 10%. hTTP will be documented by ADAMTS13 activity \ 10% during clinical remission. 3. Subjects do not exhibit any severe symptoms of TTP at the time of screening. At screening, patients with mild but stable laboratory abnormalities (LDH not higher than three times the upper limit of normal; platelet count not less than 100,000/microliter) are eligible for enrollment. 4. No stroke was detected on cranial MRI and there was no previous history of stroke. 5. The subject is willing and able to comply with the requirements of this protocol. Exclusion Criteria: 1. Subject has a history of significant neurological events, such as a major stroke, indicating that a relapse may have serious consequences, as judged by the investigator 2. Subject has increased risk for bleeding (e.g., platelet count \<30,000/µL, severe coagulopathy, gastrointestinal disease) 3. Subject has a history of drug and/or alcohol abuse within six months before enrollment. 4. Subject has a life expectancy of fewer than three months. 5. The investigator considers the subject unable or unwilling to cooperate with the study procedures. 6. The subject is a family member or employee of the investigator. 7. The patient is pregnant or breast-feeding.

ClinicalTrials.gov record NCT05568147

Aspirin for Prophylaxis of TTP

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

A Prospective Multicenter Clinical Study of Aspirin for Prophylaxis in Patients With Hereditary or Acquired Thrombotic Thrombocytopenic Purpura

About this page. This page shows the study's official ClinicalTrials.gov record ↗, with added help to make it easier to understand. We explain medical terms, highlight key details in plain language, and suggest questions you may want to ask the study team.

The record is periodically copied from ClinicalTrials.gov and may lag behind changes. AI summaries are checked by software, not a clinician.Read moreShow less

The official record is written by the study sponsor and published on ClinicalTrials.gov. It may not always reflect the latest changes. Before making any decisions, please confirm important information with the study team and your own healthcare team.

Where you see "AI summary", AI was used to create a plain-language explanation and software checked it against the source. It has not been reviewed by a clinician, so it may contain mistakes or leave out important details.

StatusNot yet recruitingThe study has been registered but has not started enrolling. Sites and contacts may not be listed yet.The registry record was last updated on Oct 5, 2022, about 4 years ago, so the status shown may be out of date. The study team or the registry can confirm.

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 2/3A study that tests whether a treatment works while continuing to check safety, in a larger group than a phase 2 study alone. It combines the aims of phase 2 and phase 3 in one protocol.

SexAll

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 randomized phase 2/3 trial that compares daily aspirin 100 mg with placebo in people with hereditary or acquired TTP in remission. The study will measure ischemic strokes, TTP relapses, and major bleeding events over up to three years. Masking is none and participants are assigned to one of two parallel groups.

What it is studying. Whether taking daily low-dose aspirin (100 mg) compared with placebo changes the number of ischemic strokes, the number of TTP relapses, and the occurrence of major bleeding events in people with hereditary (hTTP) or immune-mediated/acquired (iTTP) thrombotic thrombocytopenic purpura who are in remission.

What the researchers hope to learn. To measure the effects and safety of daily low-dose aspirin in people with hTTP and iTTP in remission by collecting data on ischemic strokes, TTP relapses, and major bleeding over three years.

What this study is about

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

Thrombotic thrombocytopenic purpura (TTP) is a rare and life-threatening thrombotic microangiopathy characterized by thrombocytopenia, microangiopathic hemolytic anemia, and microvascular thrombosis causing neurological and renal abnormalities; it is associated with massive depletion of platelets in the microvasculature to form microthrombi1 . Long-term follow-up of patients with congenital TTP (cTTP) revealed frequent strokes and renal injury. Of 217 surviving patients, 62 (29%) had a stroke; the median age was 21 years. iTTP patients also require long-term follow-up. iTTP patients with low ADAMTS13 activity (<70%) in remission have a 28% risk of stroke. Survival rates of iTTP patients in remission were lower than those of age-, race-, and sex-matched populations. In terms of stable treatment, maintenance therapy is not recommended for patients with iTTP. Previous studies have shown that aspirin may be able to prevent stroke complications in patients with cTTP and iTTP. In addition to its potential efficacy, the risks of aspirin are small and inexpensive. Aspirin is very effective in secondary prevention of stroke 6. However, the therapeutic value of aspirin in TTP has not been studied previously. To improve the prognosis and survival of patients with cTTP and iTTP, we propose to conduct a prospective study to observe the efficacy and safety of aspirin in patients with cTTP and iTTP in remission.

Interventions being studied

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

Drug: Aspirin tablet
Placebo

Eligibility

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

Inclusion criteria

Those who voluntarily signed the informed consent form and were able to comply with the study protocol.
Subjects diagnosed with severe ADAMTS13 deficiency, defined as ADAMTS13 activity <10%, documented in the patient's medical history or at screening. Note: In patients receiving fresh frozen plasma (FFP) or other prophylactic treatments containing ADAMTS13 products, plasma ADAMTS13 activity levels at screening may exceed 10%. hTTP will be documented by ADAMTS13 activity <10% and biallelic pathogenic ADAMTS13 mutations. Patients with hTTP may be asymptomatic. iTTP will be diagnosed by ADAMTS13 activity <10% and the presence of an ADAMTS13 activity inhibitor (or comparable test for anti-ADAMTS13 antibodies). The diagnosis of hTTP may be supported by the recovery of ADAMTS13 activity to >10% during clinical remission.
Subjects do not exhibit any severe symptoms of TTP at the time of screening. At screening, patients with mild but stable laboratory abnormalities (LDH not higher than three times the upper limit of normal; platelet count not less than 100,000/microliter) are eligible for enrollment.
No stroke was detected on cranial MRI and there was no previous history of stroke.
The subject is willing and able to comply with the requirements of this protocol.

Exclusion criteria

Subject has a history of significant neurological events, such as a major stroke, indicating that a relapse may have serious consequences, as judged by the investigator
Subject has increased risk for bleeding (e.g., platelet count <30,000/µL, severe coagulopathy, gastrointestinal disease)
Subject has a history of drug and/or alcohol abuse within six months before enrollment.
Subject has a life expectancy of fewer than three months.
The investigator considers the subject unable or unwilling to cooperate with the study procedures.
The subject is a family member or employee of the investigator.
The patient is pregnant or breast-feeding.

Study description and what participation involves

The study's detailed description, as published on ClinicalTrials.gov.

Show the detailed description from the registry

Thrombotic thrombocytopenic purpura (TTP) is a rare, life-threatening thrombotic microangiopathy. It is characterized by thrombocytopenia, microangiopathic hemolytic anemia, and microvascular thrombosis causing neurologic and kidney abnormalities . TTP is caused by a severe deficiency of ADAMTS13 (A Disintegrin and Metalloprotease with ThromboSpondin type 1 repeats, member 13) . Severe ADAMTS13 deficiency can be hereditary (hTTP), caused by biallelic pathogenic mutations of the ADAMTS13 genes, or acquired (iTTP), caused by anti-ADAMTS13 autoantibodies. Its main diagnostic criterion is a severe deficiency of ADAMTS13 (activity <10%) . hTTP is currently managed by prophylaxis with plasma infusions. Because lifetime plasma infusions are a major lifestyle burden, the current practice is to begin prophylaxis when ischemic symptoms occur. Evaluation of plasma prophylaxis by the International Hereditary Registry reported that it was not effective for decreasing the occurrence of acute episodes. When recombinant ADAMTS13 (rADAMTS13) is commercially available, prophylaxis may begin sooner and be more effective. Acute episodes of iTTP are effectively treated with ADAMTS13 replacement and immunosuppression. During remission, immunosuppression is recommended to prevent relapse if ADAMTS13 activity is <20%. If ADAMTS13 activity is less than normal but ≥20%, no treatment is recommended. Long-term follow-up of patients with hTTP has identified the frequent occurrence of stroke and kidney injury. Among 217 patients who survived infancy, 62 (29%) had had a stroke; the median age was 21 years. Long-term follow-up is also required for patients with iTTP. iTTP patients with low ADAMTS13 activity (<70%) during remission have a 28% risk for stroke. Survival of iTTP patients in remission is less than the age, race, and gender-match population. No maintenance treatment is recommended for patients with iTTP. Severe ADAMTS13 deficiency in patients with TTP allows the circulation of ultra-large multimers of von Willebrand factor (VWF). Turbulent circulation causes exposure of the VWF platelet binding site. Binding of the platelet VWF receptor, GPIbα, to the ultra-large VWF multimers is the essential initial which step for the initiation of thrombosis. A recent study documented that platelet binding to von Willebrand factor activates the platelet fibrinogen receptor, αIIbβ3, initiating platelet aggregation. Aspirin blocks αIIbβ3 activation and prevents platelet aggregation. Studies of TTP in mice have documented that aspirin decreases thrombosis. These data suggest that it may provide protection against stroke in patients with hTTP and iTTP. In addition to its potential efficacy, aspirin has minimal risks, and it is inexpensive. Aspirin is very effective for the secondary prevention of stroke. However, the therapeutic value of aspirin in TTP has not previously been studied. To improve the prognosis and survival of patients with hTTP and iTTP, we propose to conduct a prospective study to observe the efficacy and safety of aspirin in patients with the iTTP and hTTP in remission.

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.

If eligible, participants are randomly assigned to take an oral tablet once daily (aspirin 100 mg or matching placebo). They will be followed and monitored for up to three years after starting the study drug. Monitoring includes brain MRI to check for ischemic stroke, blood tests including ADAMTS13 activity to detect relapse, and assessment for bleeding (if major bleeding is suspected, imaging such as CT or endoscopy may be used). Participants must attend regular clinic visits and comply with study testing and follow-up.

How the study is structured. Interventional, randomized, parallel-group trial (Phase 2/3). Participants are assigned to take either aspirin 100 mg orally once daily or a placebo tablet. The study is open-label (not masked), so participants and staff know the assigned group. Outcomes (stroke by MRI, relapses, and major bleeds) are followed from first dose through about three years.

Questions you could ask

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

Some participants receive a placebo. How is that decided, and what happens for placebo-group participants when the study ends?
The registry says recruitment has not started. When is it expected to open, and can I register interest now?
No sites are listed on the registry yet. Where will the study take place?
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: Oct 1, 2022 (estimated)
Primary completion: Sep 30, 2027 (estimated)
Study completion: Sep 30, 2028 (estimated)
Target enrollment: 100 participants (estimated)
Last updated on registry: Oct 5, 2022
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: The First Affiliated Hospital of Soochow University
Principal investigator: HAN Yue, vice director hematologic department
The First Affiliated Hospital of Soochow University

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.

Jiaqian Qi, MD 📞 8618913091817 ✉ qijq@suda.edu.cn
Yue Han, MD/PhD 📞 15606133002 ✉ hanyue@suda.edu.cn

Participating sites

Study locations have not been posted on ClinicalTrials.gov yet. This study is not yet recruiting, so sites may be added when recruitment begins. The central study contact above may be able to tell you about planned sites.

Terms used on this page · explanations by MedicalUpdates.ai

Long-term follow-up: Observation that continues for years after the study treatment, often required for gene and cell therapies.
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.
at screening: The checks done before enrolment to see whether a person qualifies, such as tests, scans or a review of medical history.
upper limit of normal: The highest value of a blood test that a laboratory considers normal. Criteria such as '≤ 3 × ULN' mean the result must be no more than three times that value.
enrollment: The number of participants a study plans to include, or has included. 'Estimated' means the planned number; 'actual' means the number who joined.
MRI: A scan that uses magnets and radio waves, not X-rays, to make detailed pictures of the inside of the body. Some implants and metal objects mean a person cannot have one.
relapse: A condition that improved with treatment and has since returned or worsened.
life expectancy: Some studies require that, in the investigator's judgement, a participant is likely to live long enough to complete the study period. It is a study requirement, not a prediction about any individual.
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.
Registry: An organised collection of information about people with a particular condition, gathered over time for research. Joining a registry usually means sharing medical information, not receiving a treatment.

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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