Randomized study on hydroxyurea alone versus hydroxyurea combined with low-dose interferon-alpha 2b for chronic myeloid leukemia

Interferon-alpha (IFN-alpha) is considered the standard therapy for chronic myeloid leukemia (CML) patients not suitable for allogeneic stem cell transplantation. From 1987 through 1992, 195 patients in the Benelux with recent untreated CML were randomized between low-dose IFN-alpha 2b (3 MIU, 5 days/wk) or hydroxyurea alone (control group). The white blood cell count had to be kept less than 10 x 10(9)/L in both arms; to this end, the IFN group received additional hydroxyurea, if necessary. The complete hematologic responses at 6 months in the IFN group were 62%, versus 38% in the control group. In the IFN group, a complete hematologic response at 6 months predicted a better survival (P =.001), but such a tendency was also seen in the control group (P =.07). Cytogenetic responses in the IFN group yielded 9% complete responders, 7% partial responders (