A total of 29 evaluable patients with acute myeloid leukaemia (AML) either in relapse or resistant to initial induction daunorubicin-containing chemotherapy were given a salvage regimen consisting of moderate-dose cytosine arabinoside and mitoxantrone. There were 8 (28%) complete responders (CRs), 4 (14%) partial responders (PRs), and 17 (52%) nonresponders. The duration of CRs was 2+, 2+, 3+, 3, 4+, 4, 5 and 6 months respectively. Two of the eight CR patients were refractory to initial daunorubicin-containing induction therapy and another two had achieved a previous CR lasting < 6 months. Four of the eight CR patients had received an amsacrine-containing salvage regimen (ATA) prior to administration of the present moderate-dose cytosine arabinoside and mitoxantrone regimen; this indicates the lack of absolute clinical cross-resistance between the present combination and the daunorubicin- or amsacrine-containing regimens. However, the duration of CRs achieved by these patients remains very short and should, if possible, be followed by allogeneic or autologous bone marrow transplantation.
