To assess the long-term antithrombotic effect of low-dose aspirin (ASA) on the risk of thrombotic events in Polycythemia Vera (PV);
To assess the benefit/risk profile of low-dose aspirin in PV;
To update the natural history of PV.
Polycythemia Vera (PV) is a rare hematological myeloproliferative disorder. Notwithstanding cytoreductive treatments, thrombosis remains a major cause of morbidity and mortality in PV. Antiplatelet agents have long been considered unsafe in PV patients because of reports of gastrointestinal haemorrhage in patients receiving high aspirin (ASA) doses. ASA, on the other hand, is selectively effective in the treatment of PV vascular disturbances such as erythro-melalgia, transient neurological and ocular disturbances. In addition, asymptomatic PV patients have an enhanced in vivo production of ThromboxaneA2 that can be largely suppressed by chronic administration of low-dose ASA (50 mg daily).
Population: Women and men aged > 50 years with PV whose benefit/risk ratio of ASA therapy is considered uncertain by clinicians in charge of their care.
Experimental design: Eligible patients will be randomized to ASA (40 mg once daily) versus placebo. The randomization will be double blind, centrally co-ordinated, and stratified for each centre according to thrombotic history and duration of the disease. Patients will be followed-up over 3 years.
Observational design: A register of non-randomized patients will be developed and information will be required annually on major vascular and neoplastic events.
Sample size: 2,500 patients followed over 3 years are needed to demonstrate a 30% reduction of thrombotic events.
Organization: In each participating country, a local structure develops and co-ordinates the network of clinical centres which will adhere to the study; the International Co-ordinating Centre in Italy co-ordinates the whole study, receives data forms, and develops a centralised data-base.
Funding SchemeCSC - Cost-sharing contracts
BH7 7DW Bournemouth
413 45 Göteborg