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CRETA (Clopidogrel Responsiveness in Essential ThrombocithemiA)
Sponsor: Fondazione Policlinico Universitario Agostino Gemelli IRCCS
Summary
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.
Official title: Evaluation of Response to Clopidogrel in Patients With Essential Thrombocythemia
Key Details
Gender
All
Age Range
18 Years - Any
Study Type
OBSERVATIONAL
Enrollment
50
Start Date
2026-07-15
Completion Date
2027-12-31
Last Updated
2026-06-12
Healthy Volunteers
No
Conditions
Interventions
VerifyNow P2Y12 assay
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.
Locations (2)
Azienda USL di Pescara - Ospedale Santo Spirito
Pescara, Italy
AOU Città della Salute e della Scienza di Torino
Torino, Italy