Maintenance therapy in the myeloproliferative disorders: the current options.

Recombinant interferon alfa-2a has been shown to be an effective induction agent in essential thrombocythaemia and thrombocythaemia associated with other myeloproliferative disorders, including chronic granulocytic leukaemia, polycythaemia rubra vera and myelofibrosis. Few data exist on the use of the recombinant interferons as maintenance agents in patients with thrombocythaemia. A cohort of 22 previously untreated patients, with essential thrombocythaemia, were treated with recombinant interferon alfa-2a maintenance therapy for a minimum period of 6 months. Effective long-term control of platelet counts, without evidence of haematological toxicity, was achieved in 19/22 patients. No objective haemorrhagic or thrombotic event occurred in 298 patient-months of interferon therapy. Three patients discontinued interferon alpha therapy due to adverse side-effects. Interferon alfa-2a is an effective maintenance agent in essential thrombocythaemia and is discussed in this context.