ANAGRELIDE FOR TREATMENT OF PATIENTS WITH CHRONIC MYELOGENOUS LEUKEMIA AND A HIGH PLATELET COUNT

Chronic myelogenous leukemia (CML) is usually treated with hydroxyurea or interferon-a, In some patients high platelet counts develop althou gh leukocyte counts are well controlled with these drugs, If in such a situation cytoreductive therapy has to be intensified by a increase o f the dosage, anemia and leukocytopenia as well as adverse effects of the drugs are likely to occur, In twelve CML patients we have therefor e combined the basic CML treatment with anagrelide, This drug which se lectively reduces platelet counts has been shown to be efficacious in the control of thrombocytosis in essential thrombocythemia, The diagno sis had been confirmed in all CML patients by cytogenetic and/or molec ular biological analysis, The median age of our group was 58 years, Fi ve were women and seven men, All patients were on treatment with hydro xyurea, some of them had previously received treatment with interferon -a (alone or in combination with hydroxyurea), busulfan or melphalan. Prior to the initiation of anagrelide treatment the platelet count was between 970,000 and 3,600,000/mu l (median about 2,000,000/mu l), Sev en patients had thrombohemorrhagic complications, All twelve patients, experienced hematologic responses, since their platelet counts decrea sed to less than 600,000/mu l. The median platelet count after reducti on was 343,000/mu l. The median dosage required to achieve these respo nses and to maintain them for a period of at least four weeks was 1.9 mg/day, Thrombohemorrhagic complications disappeared or did not recur in all symptomatic patients, Adverse effects were seen in 3/12 patient s: headache (1), tachycardia (1), palpitation (1) and fluid retention (1). Whereas these symptoms were mild and transitory they caused one p atient to request discontinuation of treatment. Currently five patient s are still on treatment with anagrelide (median duration of treatment 11 months) while therapy had to be discontinued in the seven others b ecause of bone marrow transplantation, development of osteomyelofibros is, blast crisis or on patient request, In our experience anagrelide i s a useful therapeutic adjunct when thrombocytosis in patients with CM L cannot properly controlled alone with traditional drugs.