Prolonged chronic phase in chronic myelogenous leukemia after homoharringtonine therapy

Homoharringtonine (HHT) is effective in treating late stage chronic myelogenous leukaemia (CML), but little is known about long term maintenance during complete cytogenetic response. Long term efficacy and toxicity profiles of low dose HHT were evaluated in this study.

One hundred and six patients with CML received 1.5 mg/m(2) of HHT alone by continuous daily infusion for seven to nine days every four weeks. Of 79 patients in the control group, 31 were treated with interferon alpha (IFN-alpha) and 48 with hydroxycarbamide. For 17 patients who failed to achieve cytogenetic response within 12 months' treatment of IFN-alpha, HHT was administered. Quantitative RT-PCR was used to detect the BCR-ABL mRNA expression in 36 Philadelphia positive CML patients enrolled after 2007. Haematological and cytogenetic responses were evaluated in all patients at the 12th month of follow-up. Long term efficacy was assessed in a follow-up with a median time of 54 months (12 months-98 months).

After 12 months of therapy, cytogenetic response rate of the HHT, IFN-alpha and hydroxycarbamide groups were 39/106, 14/31 and 3/48, and corresponding molecular cytogenetic response rates 6/18, 3/8 and 0. Of the 17 patients who received HHT as salvage treatment, 6 achieved cytogenetic response (3 major). At the 48 months' follow-up, cytogenetic response was maintained in 32/39 patients treated with HHT. Patients who had cytogenetic response in HHT group or treated with IFN-alpha also showed longer median chronic durations, which were 45 months (12 months-98 months) and 49 months (12 months-92 months) respectively, indicating a longer survival time.

Low dose HHT alone showed considerable short term and long term efficacy in the treatment of late stage CML. It may also be a good choice for patients who have failed imatinib, IFN-alpha treatment or haematopoietic stem cell transplantation or cannot afford these treatments.