Essential thrombocythemia (ET) is a myeloproliferative neoplasm characterized by enhanced platelet production and thrombotic complications. The inhibition of platelet cyclooxygenase (COX) activity by the standard once-daily aspirin is mostly incomplete due to accelerated thrombopoiesis. The phase-2 Aspirin Regimens in EsSential thrombocythemia (ARES) trial has recently compared the efficacy of once- versus twice- or three-times daily low-dose aspirin in inhibiting platelet thromboxane (TX) A2 production, as reflected by serum (s) TXB2 measurements. The present sub-study characterized the determinants of the highly variable response to the standard aspirin 100 mg once-daily regimen in fully-compliant ET patients and the effects of the experimental dosing regimens on response variability.
Association of platelet thromboxane inhibition by low-dose aspirin with platelet count and cytoreductive therapy in essential thrombocythemia. Tosetto A, Rocca B, Petrucci G, Betti S, Soldati D, Rossi E, Timillero A, Cavalca V, Porro B, Iurlo A, Cattaneo D, Bucelli C, Dragani A, Di Ianni M, Ranalli P, Palandri F, Vianelli N, Beggiato E, Lanzarone G, Ruggeri M, Carli G, Elli EM, Priolo S, Randi ML, Bertozzi I, Loscocco GG, Ricco A, Specchia G, Vannucchi AM, Rodeghiero F, De Stefano V, Patrono C; Aspirin Regimens in EsSential thrombocythemia (ARES) Investigators. Clin Pharmacol Ther. 2021 Nov 7. doi: 10.1002/cpt.2485