Safety and efficacy of the combination of pegylated interferon-α2b and dasatinib in newly diagnosed chronic-phase chronic myeloid leukemia patients

Dasatinib (DAS) and interferon-α have antileukemic and immunostimulatory effects and induce deep responses in chronic myeloid leukemia (CML). We assigned 40 newly diagnosed chronic-phase CML patients to receive DAS 100 mg o.d. followed by addition of pegylated interferon-α2b (PegIFN) after 3 months (M3). The starting dose of PegIFN was 15 μg/week and it increased to 25 μg/week at M6 until M15. The combination was well tolerated with manageable toxicity. Of the patients, 84% remained on PegIFN at M12 and 91% (DAS) and 73% (PegIFN) of assigned dose was given. Only one patient had a pleural effusion during first year, and three more during the second year. After introduction of PegIFN we observed a steep increase in response rates. Major molecular response was achieved in 10%, 57%, 84% and 89% of patients at M3, M6, M12 and M18, respectively. At M12, MR(4) was achieved by 46% and MR(4.5) by 27% of patients. No patients progressed to advanced phase. In conclusion, the combination treatment appeared safe with very promising efficacy. A randomized comparison of DAS±PegIFN is warranted.