A Phase 3 interventional study of Direct Oral Anticoagulants and Low-dose aspirin in Polycythemia Vera, Essential Thrombocythemia and Prefibrotic/Early Primary Myelofibrosis, sponsored by University Hospital, Brest. Recruiting at 42 sites in France. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-03-20.
Sponsored by University Hospital, Brest · Phase 3, Interventional, and Prevention
Philadelphia-negative myeloproliferative neoplasms (MPN) are frequent and chronic myeloid malignancies including Polycythemia Vera (PV), essential thrombocythemia (ET), Primary Myelofibrosis (PMF) and Prefibrotic myelofibrosis (PreMF). These MPNs are caused by the acquisition of mutations affecting activation/proliferation pathways in hematopoietic stem cells. The principal mutations are JAK2V617F, calreticulin (CALR exon 9) and MPL W515. ET or MFP/PreMF patients who do not carry one of these three mutations are declared as triple-negative (3NEG) cases even if they are real MPN cases.
These diseases are at high risk of thrombo-embolic complications and with high morbidity/mortality. This risk varies from 4 to 30% depending on MPN subtype and mutational status.
In terms of therapy, all patients with MPNs should also take daily low-dose aspirin (LDA) as first antithrombotic drug, which is particularly efficient to reduce arterial but not venous events.
Despite the association of a cytoreductive drug and LDA, thromboses still occur in 5-8% patients/year.
All these situations have been explored in biological or clinical assays. All of them could increase the bleeding risk. We should look at different ways to reduce the thrombotic incidence: Direct Oral Anticoagulants (DOAC)? In the general population, in medical or surgical contexts, DOACs have demonstrated their efficiency to prevent or cure most of the venous or arterial thrombotic events.
At the present time, DOAC can be used in cancer populations according to International Society on Thrombosis and Haemostasis (ISTH) recommendations, except in patients with cancer at high bleeding risk (gastro-intestinal or genito-urinary cancers). Unfortunately, in trials evaluating DOAC in cancer patients, most patients have solid rather than hematologic cancers (generally less than 10% of the patients, mostly lymphoma or myeloma).
In cancer patients, DOAC are also highly efficient to reduce the incidence of thrombosis (-30 to 60%), but patients are exposed to a higher hemorrhagic risk, especially in digestive cancer patients.
In the cancer population, pathophysiology of both thrombotic and hemorrhagic events may be quite different between solid cancers and MPN. If MPN patients are also considered to be cancer patients in many countries, the pathophysiology of thrombosis is quite specific (hyperviscosity, platelet abnormalities, clonality, specific cytokines…) and they are exposed to a lower risk of digestive hemorrhages. It is thus difficult to extend findings from the "general cancer population" to MPN patients.
Unfortunately, only scarce, retrospective data regarding the use of DOAC in MPNs are available data.
We were the first to publish a "real-life" study about the use, the impact, and the risks in this population. In this local retrospective study, 25 patients with MPN were treated with DOAC for a median time of 2.1 years. We observed only one thrombosis (4%) and three major hemorrhages (12%, after trauma or unprepared surgery). Furthermore, we have compared the benefit/risk balance compared to patients treated with LDA without difference.
With the increasing evidences of efficacy and tolerance of DOAC in large cohorts of patients including cancer patients, with their proven efficacy on prevention of both arterial and venous thrombotic events and because of the absence of prospective trial using these drugs in MPN patients, we propose to study their potential benefit as primary thrombotic prevention in MPN.
278 studies on the registry are indexed under Polycythemia Vera; 53 are open to participants now.
This study's planned enrollment of 1,308 is above the median of 52 across 204 interventional studies indexed under Polycythemia Vera.
Browse Polycythemia Vera studies →University Hospital, Brest is the lead sponsor of 601 studies on the registry; 136 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Patients considered as "high-risk" patients:
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
A biopsy takes a small piece of tissue to examine. “Archival tissue” is a sample already taken, for example at diagnosis, and kept by the hospital.
Whether a stored sample will do depends on when it was taken, how much there is and what the study needs. Ask whether the study accepts your stored sample or needs a new biopsy.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
CYP3A is a group of enzymes, mainly CYP3A4, in the liver and gut that break down many medicines. Some medicines, supplements and foods (grapefruit, St John’s wort) slow them down or speed them up, which changes how much of a study drug stays in the body.
Studies list them so they can be avoided or switched; bring a list of everything you take, including supplements.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.
Biopsy and archival tissue
A biopsy takes a small piece of tissue to examine. “Archival tissue” is a sample already taken, for example at diagnosis, and kept by the hospital.
Whether a stored sample will do depends on when it was taken, how much there is and what the study needs. Ask whether the study accepts your stored sample or needs a new biopsy.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
CYP3A (CYP3A4) inhibitors and inducers
CYP3A is a group of enzymes, mainly CYP3A4, in the liver and gut that break down many medicines. Some medicines, supplements and foods (grapefruit, St John’s wort) slow them down or speed them up, which changes how much of a study drug stays in the body.
Studies list them so they can be avoided or switched; bring a list of everything you take, including supplements.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Life expectancy
The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Patients randomized to receive Direct Oral Anticoagulants, at the choice of the investigator Apixaban 2.5 mg both in day or Rivaroxaban 10 mg one per day, at the choice of the investigator
Drug: Direct Oral Anticoagulants
Patients randomized to receive Low-Dose Aspirin Aspirin 100 mg one per day
Drug: Low-dose aspirin
Patients randomized to receive DOAC, at the choice of the investigator: Apixaban 2.5 mg both in day or Rivaroxaban 10 mg once daily.
Patients allocated to receive LDA: Aspirin 100 mg OD once daily.
Time to occurrence of arterial or venous thromboembolic events.
Nb and type of thrombotic events during the FU
Time frame: Time to occurrence up to 24 months of patient follow-up
Time to occurrence of major and clinically relevant non-major bleedings as defined by International Society on Thrombosis and Haemostasis
Nb and type of new hemorrhagic events
Time frame: Time to occurrence up to 24 months of patient follow-up
Time to occurrence of arterial thromboembolic events.
Nb and type of new arterial events
Time frame: Time to occurrence up to 24 months of patient follow-up
Time to occurrence of venous thromboembolic
Nb and type of new venous events
Time frame: Time to occurrence up to 24 months of patient follow-up
Time to occurrence of thromboembolic and bleeding events according to the cytoreductive associated drugs
Nb and type of new thromboembolic and hemorrhage events
Time frame: Time to occurrence up to 24 months of patient follow-up
Time to occurrence of serious adverse events others than thromboses and hemorrhages hemorrhages
Nb, type and grade of adverse events observed
Time frame: Time to occurrence up to 24 months of patient follow-up
Overall survival and event-free survival
Time to last news and time to first event
Time frame: 24 months
Therapeutic adherence
Therapeutic adherence by Girerd auto-questionnaire
Time frame: 24 months
Occurrence of atrial fibrillation episode (time to occurrence).
Nb and timing of atrial fibrillation event
Time frame: 24 months
Evaluation of Quality of life under antithrombotic drugs
Evaluation of QoL by the use of MPN-SAF Quality of life
Time frame: 24 months
Evaluation of costs and incremental cost utility ratio of low-dose DOAC compared to low-dose aspirin
Evaluation of benefits/costs under antithrombotic drugs
Time frame: 24 months
Evaluation of Quality of life under antithrombotic drugs
Evaluation of QoL by the use of EQ-5D-5L Quality of life
Time frame: 24 months
Plan to share: Yes — All collected data that underlie results in a publication
Supporting information: Study protocol
Time frame: Data will be available beginning five years and ending fifteen years following the final study report completion.
Access criteria: Data access requests will be reviewed by the internal committee of Brest UH. Requestors will be required to sign and complete a data access agreement.
No publications or documents are linked to this record.
Started Jul 2022 (actual). Primary completion is estimated for Jul 2027, 60 months after the start.
How these figures are worked out, and which studies are left out of them.
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Studies of the drug tested here: Direct Oral Anticoagulant