A guide to the use of interferon-alpha in the management of chronic myelogenous leukaemia

Interferon-alpha (IFNα) can induce major cytogenetic responses in 30 to 40% of patients with chronic myelogenous leukaemia (CML) and up to 50% when combined with cytarabine (ara-C). These responses translate into a survival advantage. However, the management of patients treated With IFNα requires experience to optimise the therapy. The optimal dose should be used and the addition of ara-C should be considered. It is advisable to lower the white blood cell count (WBC) before the start of therapy and increase the dose to the ideal dose gradually over 1 to 2 weeks. Some myelosuppression should be tolerated to keep a WBC in the range of 2 to 4 x 10⁹/L. Dosages should be adjusted as needed when grade 3 or persistent grade 2 toxicity occurs, and adverse effects should be managed promptly and aggressively to improve tolerance. Patients should be monitored closely with cytogenetic and possibly other analyses such as fluorescent in situ hybridisation (FISH) and polymerase chain reaction (PCR) to determine response. The duration of therapy is controversial, but it should be kept in mind that whenever the decision is made to use IFNα for therapy in CML, the patient should be given the best opportunity to achieve a cytogenetic response as this will probably translate into a survival advantage.