Idarubicin and intermediate dose ARA-C followed by consolidation chemotherapy or bone marrow transplantation in relapsed or refractory acute myeloid leukemia.

Sixty-one adult patients with relapsed or refractory acute myelogenous leukemia (AML) were treated in a cooperative study with Idarubicin 12 mg/m2/day on days 1 to 3 and AraC 1 g/m2/12h on days 1 to 4. Responding patients were scheduled for consolidation with Ida-IDAraC and bone marrow transplantation (BMT) when feasible. Twelve of 23 refractory patients (52%) and 21 of 38 relapsed patients (55%) achieved complete remission (CR). Refractory patients treated very early with Ida-IDAraC (CR 63%) and relapsed patients with initial CR > 6 months (CR 68%) were the subgroups with better CR rate. The only factor influencing the disease free survival (DFS) was the intensity of postremission therapy: Nine patients had severe toxicity with the salvage regimen and were excluded for consolidation, fourteen patients received Ida-IDAraC and ten patients proceeded to myelo-ablative therapy supported with autologous or allogeneic BMT. The three groups had different median DFS of 6 months, 9 months and 15 months respectively (P = 0.017). In summary, Ida-AraC is an efficient salvage regimen for AML. The CR rate seems to be improved in refractory patients if used promptly, but the long term outcome appears to depend on the intensity of treatment given once remission is achieved and on the ability to perform BMT.