Treatment with lymphoblastoid alpha interferon in patients with chronic myeloid leukemia refractory to recombinant interferon alpha 2

: The results of the treatment with lymphoblastoid alpha interferon (IFN-alpha N1) in 10 patients with chronic myeloid leukaemia who had poor response to previous recombinant alpha interferon (rIFN-alpha) are presented. Eight of these patients had not developed anti-alpha 2 interferon antibodies, and 2 had non-neutralising anti-IFN antibodies. Three of the 10 patients received benefit from IFN-alpha N1 treatment. Two of them, with no response to rIFN alpha 2, attained complete haematologic response wit IFN-alpha N1. Cytogenetic responses although minimal, were achieved as well. The third patient, after receiving rIFN-alpha for 3 years with no response, had partial cytogenetic response after 4 months of treatment with IFN-alpha N1. These results suggest that IFN-alpha N1 when used in patients refractory to IFN-alpha N1. These results suggest that IFN-alpha N1 when used in patients refractory to IFN alpha 2 without anti-IFn alpha 2 neutralising antibodies may be useful in a minority of patients, although the frequency of cytogenetic responses is low.