Essential ThrombocythemiaCRETANCT07645755
CRETA (Clopidogrel Responsiveness in Essential ThrombocithemiA)
An observational study of Essential Thrombocythemia, run by Fondazione Policlinico Universitario Agostino Gemelli IRCCS at 2 sites in Italy.
Trial summary
Essential thrombocythemia (ET) is a chronic myeloproliferative neoplasm associated with increased platelet production and activation, leading to a high risk of thrombotic complications. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Essential Thrombocythemia
- What is being tested?
- VerifyNow P2Y12 assay
- How many people
- 50 participants
- Where
- 2 sitesItaly
- Study dates
- 15 Jul 2026to 31 Dec 2027
- Phase
- Observational
- 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
Study population: Consecutive Patients with ET, with an approved indication for clopidogrel therapy (i.e., aspirin intolerance) and a documented good or poor response to the standard 75 mg od dose of clopidogrel at maintenance, as assessed by the standard VN-P2Y12 poinr of care, platelet function test. At least 50 patients will be enrolled, based on the current records of the participating Centers.
Who may be able to join
- Male or female subjects age ≥ 18 years;
- Confirmed diagnosis of ET according to the 2022 WHO classification criteria30;
- Patients treated with clopidogrel 75 mg od as antithrombotic prophylaxis since at least 3 weeks, as per the indication of the referring hematologist;
- Ability to understand the nature of the study and voluntarily provide written informed consent patients whose responsiveness to the standard clopidogrel regimen was determined, based on clinical practice, using the VN-P2Y12 method.
Who cannot join
- Platelet count >1,000,000/μL on three separate determinations within the 2 months prior to enrollment;
- Need for anticoagulant therapy;
- Concomitant use of other antiplatelet agents;
- Chronic use of non-steroidal anti-inflammatory drugs (NSAIDs) (i.e > 3 days per week);
- Chronic corticosteroid therapy exceeding a daily dose equivalent to prednisone 5 mg
Trial locations and contacts
2 sites in 1 country. Contact the study team or a site near you to ask about taking part.
Italy2 sites
Azienda USL di Pescara - Ospedale Santo Spirito
Pescara, 65124
Paola Ranalli, paola.ranalli@asl.pe.it
Paola Ranalli
AOU Città della Salute e della Scienza di Torino
Torino, 10126
Eloise Beggiato, ebeggiato@cittadellasalute.to.it
Eloise Beggiato
About this study
Official title: Evaluation of Response to Clopidogrel in Patients With Essential Thrombocythemia
Essential thrombocythemia (ET) is a chronic myeloproliferative neoplasm associated with increased platelet production and activation, leading to a high risk of thrombotic complications. Low-dose aspirin is the standard antiplatelet therapy for thrombosis prevention; however, the accelerated platelet turnover characteristic of ET results in rapid recovery of platelet function, making once-daily aspirin insufficient in many patients. Consequently, twice-daily low-dose aspirin is currently recommended to achieve adequate and sustained platelet inhibition.
For patients intolerant to aspirin, clopidogrel 75 mg/day is the approved alternative. Clopidogrel irreversibly inhibits the platelet P2Y12 receptor, but its pharmacodynamic effect is highly variable because it is a prodrug requiring metabolic activation. Studies in non-ET populations have shown that higher clopidogrel doses (150 mg/day) provide stronger and more consistent platelet inhibition without significantly increasing bleeding risk.
Evidence on clopidogrel use in ET is limited, but available data suggest that standard-dose therapy may result in inadequate platelet inhibition, potentially reducing antithrombotic efficacy. Platelet function testing can identify patients with high residual platelet reactivity ("poor responders"), who may benefit from dose escalation. Therefore, in ET patients requiring clopidogrel therapy, assessment of platelet responsiveness may help optimize treatment, ensuring adequate platelet inhibition and potentially improving protection against thrombotic events.
- Conditions
- Essential Thrombocythemia
- Being tested
- VerifyNow P2Y12 assay
- Medical subject headings
- Thrombocythemia, Essential
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
VerifyNow P2Y12 assayDiagnostic test
The VerifyNow® system is a commercially available, CE-certified point-of-care device developed to measure P2Y12 receptor-mediated platelet aggregation in whole blood by turbidimetric-based optical detection in patients treated with clopidogrel or other P2Y12 inhibitors.
What is being measured
The primary outcome is the main question the study is designed to answer.
pharmacodynamic effectiveness of different clopidogrel dosing
To assess the pharmacodynamic effectiveness of an optimised clopidogrel dosing (75 mg bid) in ET patients with documented poor responsiveness to 75 mg od.
Measured: 15 days
Secondary outcomes (2)
proportion of patients ET treated with standard-dose clopidogrel
To estimate the proportion of patients ET treated with standard-dose clopidogrel (75 mg once daily) who exhibit poor pharmacodynamic response to clopidogrel across
Measured: 15 days
consistency over time of pharmacodynamic response
To assess the consistency over time of pharmacodynamic response in patients who are documented as good responders to clopidogrel 75 mg once daily with validated platelet function assays.
Measured: 15 days
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted12 Jun 2026
- Study start15 Jul 2026 (estimated)
- Primary completion31 Jul 2027 (estimated)
- Study completion31 Dec 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Essential ThrombocythemiaStudies of the same condition, open and under way.
- More trials run by Fondazione Policlinico Universitario Agostino Gemelli IRCCSThe 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
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 50 participants (estimated)
Sponsor and investigators
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Elena Rossi, Principal investigator, Fondazione Policlinico Universitario Agostino Gemelli IRCCS
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07645755
- Sponsor's protocol ID
- 27515
- Acronym
- CRETA
- Status last verified
- Jun 2026
- First submitted
- 9 Jun 2026
- Last updated
- 12 Jun 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 12 Jun 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Evaluation of Response to Clopidogrel in Patients With Essential Thrombocythemia
- ClinicalTrials.gov ID
- NCT07645755
- Acronym / sponsor ID
- CRETA / 27515
- Conditions
- Essential Thrombocythemia
- Study type
- Observational
- Recruitment status
- Not yet recruiting
- Enrolment
- 50 participants (estimated)
- Lead sponsor
- Fondazione Policlinico Universitario Agostino Gemelli IRCCSUniversity, hospital or other
- Study start
- 15 Jul 2026 (estimated)
- Primary completion
- 31 Jul 2027 (estimated)
- Study completion
- 31 Dec 2027 (estimated)
- First posted
- 12 Jun 2026 (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.
Essential thrombocythemia (ET) is a chronic myeloproliferative neoplasm associated with increased platelet production and activation, leading to a high risk of thrombotic complications. Low-dose aspirin is the standard antiplatelet therapy for thrombosis prevention; however, the accelerated platelet turnover characteristic of ET results in rapid recovery of platelet function, making once-daily aspirin insufficient in many patients. Consequently, twice-daily low-dose aspirin is currently recommended to achieve adequate and sustained platelet inhibition.
For patients intolerant to aspirin, clopidogrel 75 mg/day is the approved alternative. Clopidogrel irreversibly inhibits the platelet P2Y12 receptor, but its pharmacodynamic effect is highly variable because it is a prodrug requiring metabolic activation. Studies in non-ET populations have shown that higher clopidogrel doses (150 mg/day) provide stronger and more consistent platelet inhibition without significantly increasing bleeding risk.
Evidence on clopidogrel use in ET is limited, but available data suggest that standard-dose therapy may result in inadequate platelet inhibition, potentially reducing antithrombotic efficacy. Platelet function testing can identify patients with high residual platelet reactivity ("poor responders"), who may benefit from dose escalation. Therefore, in ET patients requiring clopidogrel therapy, assessment of platelet responsiveness may help optimize treatment, ensuring adequate platelet inhibition and potentially improving protection against thrombotic events.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Consecutive Patients with ET, with an approved indication for clopidogrel therapy (i.e., aspirin intolerance) and a documented good or poor response to the standard 75 mg od dose of clopidogrel at maintenance, as assessed by the standard VN-P2Y12 poinr of care, platelet function test. At least 50 patients will be enrolled, based on the current records of the participating Centers.
Key inclusion criteria (4 listed)
- Male or female subjects age ≥ 18 years;
- Confirmed diagnosis of ET according to the 2022 WHO classification criteria30;
- Patients treated with clopidogrel 75 mg od as antithrombotic prophylaxis since at least 3 weeks, as per the indication of the referring hematologist;
- Ability to understand the nature of the study and voluntarily provide written informed consent patients whose responsiveness to the standard clopidogrel regimen was determined, based on clinical practice, using the VN-P2Y12 method.
Key exclusion criteria (5 listed)
- Platelet count >1,000,000/μL on three separate determinations within the 2 months prior to enrollment;
- Need for anticoagulant therapy;
- Concomitant use of other antiplatelet agents;
- Chronic use of non-steroidal anti-inflammatory drugs (NSAIDs) (i.e > 3 days per week);
- Chronic corticosteroid therapy exceeding a daily dose equivalent to prednisone 5 mg
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 |
|---|---|---|
| VerifyNow P2Y12 assayThe VerifyNow® system is a commercially available, CE-certified point-of-care device developed to measure P2Y12 receptor-mediated platelet aggregation in whole blood by turbidimetric-based optical detection in patients treated with clopidogrel or other P2Y12 inhibitors. | Diagnostic test | – |
Primary outcome
pharmacodynamic effectiveness of different clopidogrel dosing
Time frame: 15 days
To assess the pharmacodynamic effectiveness of an optimised clopidogrel dosing (75 mg bid) in ET patients with documented poor responsiveness to 75 mg od.
2 secondary outcomes
proportion of patients ET treated with standard-dose clopidogrel
Time frame: 15 days
consistency over time of pharmacodynamic response
Time frame: 15 days
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 12 Jun 2026.
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RecruitingPhase 3
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RecruitingPhase 1
A Phase 1 Study of PRT12396 in Participants With Select Myeloproliferative Neoplasms
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Recruiting
Functional and Phenotypic Characterization of Monocytes in Myeloproliferative Syndromes
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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.
Elena Rossi principal investigator
Fondazione Policlinico Universitario Agostino Gemelli IRCCS
2 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Essential Thrombocythemia, run by Fondazione Policlinico Universitario Agostino Gemelli IRCCS at 2 sites in Italy.
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 4 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: opening soon, as of the sponsor's last update on 12 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 2 sites in Italy. 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.
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 Elena Rossi (+39 0630154206, elena.rossi@policlinicogemelli.it), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
pharmacodynamic effectiveness of different clopidogrel dosing (time frame: 15 days). 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 12 Jun 2026.