Successful Treatment of Accelerated and Blastic Phase of Chronic Myeloid Leukemia with High-Dose Interferon-alpha Combined with Hydroxyurea

Abstract

Transformed chronic myeloid leukemia (CML) has a dismal prognosis, and treatment with a variety of chemotherapeutic agents is extremely disappointing. A novel therapeutic approach was initiated to improve the outcome of this condition. Nine patients, four females and five males, with either acceleration of CML or blast crisis (myeloid), or, in two instances, both, entered this pilot study. Median age was 60 years; seven patients were Philadelphia chromosome positive; two were negative but showed a bcr/abl rearrangement. All patients had a well-defined preceding period of stable chronic phase, for which they received sequentially hydroxyurea (N = 9), interferon (IFN) (N = 3), busulfan (N = 2), melphalan (N = 1), 6-MP (N = 1), or allogeneic BMT (N = 1). Median length of preceding chronic phase to acceleration or blast crisis was 56 months. All patients responded to treatment with a starting dose of IFN (9 Mio U/day), subcutaneously, and hydroxyurea (3 g/day), orally, by reversal to chronic phase. Three of the patients responded repeatedly during their course of disease. Median time for reversal to chronic phase was 4 weeks. Adverse side effects like nausea, vomiting, hair loss, fever, and prolonged cytopenia as seen after chemotherapy were not observed. The duration of chronic phase varied, and lasted, in six instances, more than 5 months, while the Philadelphia chromosome persisted. One additional patient received an unrelated bone marrow transplantation after reaching chronic phase (+24 months). Disease progression occurred 2 months after cessation of treatment. This treatment has proven very promising so far.