HIGH RESPONSE RATE USING RECOMBINANT INTERFERON-ALPHA IN PATIENTS WITH NEWLY-DIAGNOSED CHRONIC MYELOID-LEUKEMIA

To improve the management of chronic myeloid leukemia (CML) in a singl e center, we have used interferon-alpha (IFN-alpha) to treat newly dia gnosed Ph-positive CML patients and investigated the factors predictiv e of a major cytogenetic response. Eighty-one patients with a median a ge of 50.5 y (17-70) were given IFN-alpha (5 x 10(6)/sqm/day, s.c.). T he median interval between diagnosis and IFN-alpha was 45 days (0-160) . IFN-alpha doses were adjusted to maintain the white blood cell (WBC) count between 1.5 and 5 x 10(9)/l and the platelet count between 50 a nd 100 x 10(9)/l. At diagnosis, Sokal's criteria were used to classify patients into three groups: low (n = 39), intermediate (n = 32) and h igh risk (n = 10). A complete hematological response (CHR) was achieve d in 66 cases (81.5%). Cytogenetic response was evaluated in these 66 responders. Thirty-six patients (44.4%) achieved a major cytogenetic r esponse (MCR) (greater than or equal to 65% Ph-negative cells), 31 of them having a complete cytogenetic response. The 5-y transformation-fr ee survival (TFS) of the 81 patients was 77 +/- 14% (95% CI) and was s tatistically influenced by the CHR rate at three months (p = 0.008) an d the achievement of MCR or CCR (p < 0.0009 and p < 0.0005, respective ly). Moreover, we found that the MCR or CCR were significantly influen ced by the obtaining of CHR at three months (p < 0.0001 and p < 0.0001 , respectively). These results show that IFN-alpha can induce high rat es of hematological and cytogenetic responses when administered in dos es leading to myelosuppression. The achievement of CHR within three mo nths could be useful to identify early those patients who will not res pond to IFN-alpha and who need alternative treatments such as allogene ic or autologous stem cell transplantation.