Bone marrow evaluation according to the PVSG and WHO criteria in 90 essential thrombocythemia (ET) patients treated with PEG interferon alpha-2b. Preliminary results

Ninety ET patients diagnosed according to the PVSG criteria were enrolled in a phase II study (sponsored by the Schering-Plough Company) designed to evaluate the efficacy, safety and tolerability of a two years treatment with PEG Interferon alpha-2 b (PEG Intron). The patients, observed in 16 Italian Centres belonging to the GIMEMA Cooperative Group and judged at high risk, had been previously treated with cytoreductive (97%) and antiplatelet (91%) drugs. At the study start the patients, 60 F and 30 M, mean age 45 years, showed splenomegaly in 22% of cases. The Hematological Response (HR: PLT