Sequential treatment of Ph-positive chronic myeloid leukemia with interferon gamma and interferon alpha

Several clinical observations have shown that alpha-IFN is presently the most interesting investigational agent for the treatment of Ph+ chronic myeloid leukemia (CML). Gamma-IFN is also effective, and experimental data as well as preliminary clinical observations suggest that the combination of the two IFNs is worth investigating. No comparative data are available on the effects of the two IFNs, given alone, in the same patients. In this study 11 patients with PH+ CML were first treated with gamma-IFN, up to a maximum period of 35 weeks, and after a short rest period were retreated with alpha-IFN. Both IFNs were ineffective in 3 patients in accelerated or instable chronic phase. Both IFNs were equally effective in 8 patients in stable chronic phase, but none of these patients achieved a karyotypic conversion with either IFN. This study did not show any measurable differences in the therapeutic response to gamma-IFN and alpha-IFN given consecutively to the same patients.