Effect of Interferon-α on Patients with Previously Untreated Chronic Myelogenous Leukemia in the Early Chronic Phase: Comparison between Interferon-α Continued Patients and Interferon-α Discontinued Patients

Abstract

In order to confirm the effect of interferon-α (IFN-α) in inducing a prolonged duration of the chronic phase (CP) on patients with chronic myelogenous leukemia (CML), we retrospectively compared the duration of CP between patients who continued on IFN-α and the patients in whom IFN-α was discontinued before the blast phase.

Of the 32 patients not pretreated for CML in the early CP who received IFN-α therapy, 25 continued on IFN-α while seven discontinued the therapy (side effects, 5; resistance, 1; patient's refusal, 1). Only four of the 25 patients in whom IFN-α was continued (16.0%) progressed to the blast phase or accelerated phase, but six of the seven patients who discontinued IFN-α (85.7%) progressed to the blast phase or accelerated phase. Fourteen of the 25 patients who continued on IFN-α therapy showed cytogenetic response (complete cytogenetic response, 3; minimal cytogenetic response, 11) whereas 11 patients showed no cytogenetic response. However, non-responders showed a longer duration of CP than the patients whom IFN-α was discontinued.

Although elderly patients showed a high incidence of side effects, and some patients progressed early after the beginning of IFN-α therapy, our data clearly demonstrated that in accordance with previous large multi-centric randomized studies the continuation of IFN-α, even in low doses, prevents disease progression.

Keywords:

• Chronic myelogenous leukemia
• chronic phase
• interferon-α
• side effect