COMPARISON OF TOXICITY AND OUTCOME IN PATIENTS WITH ACUTE MYELOID-LEUKEMIA TREATED WITH HIGH-DOSE CYTOSINE-ARABINOSIDE CONSOLIDATION AFTER INDUCTION WITH A REGIMEN CONTAINING IDARUBICIN OR DAUNORUBICIN

The toxicity and outcome after high-dose ara-C/daunorubicin (HDara-C/D NR) consolidation therapy in de novo AML was compared in 11 patients w ho received an idarubicin-containing induction therapy (IDA; from June 1995 to March 1997) and 16 patients pretreated with daunorubicin (DNR ; from July 1990 to May 1995) for induction. The DNR group consisted o f two cohorts, one (n = 6) of patients who had received, as had the ID A group, two induction and one intermediate-dose ara-C consolidation c ourses, and another (n = 10) of patients who had been pretreated with one induction and one consolidation course prior to HDara-C/DNR. There was no difference in the relative dose between the three cohorts. Fol lowing HDara-C/DNR, the IDA-pretreated patients experienced a more pro longed myelosuppression during consolidation therapy compared with the DNR group. Duration of neutropenia (<500 neutrophils/mu l) following HDara-C/DNR was 31.2 +/- 16 days (mean +/- SEM) in the IDA group compa red with 18.7 +/- 5 days in the DNR group (p<.001 Mann-Whitney U-test) . The duration of thrombocytopenia (platelets <25 000/mu l) was 34.8 /- 20 days in the IDA group vs. 18.5 +/- 6 days in the DNR group (p<.0 05). The more prolonged myelosupression was associated with a longer d uration of fever (18.9 +/- 24 vs. 6.9 +/- 5.2 days). A greater inciden ce, length (11 +/- 8 vs. 1.2 +/- 2 days), and severity of diarrhea wer e observed in the IDA-pretreated group. Three of 11 IDA patients exper ienced WHO grade III-IV diarrhea. In the IDA group two patients develo ped severe enterocolitis with Candida septicemia, and one of these pat ients died. One patient in the IDA group died during prolonged aplasia . In the DNR group 6/16 patients experienced grade I-II diarrhea. Two patients in each group died during consolidation therapy. The CR rate was 87% in the IDA group and 79% in the DNR group. Relapse-free surviv al after HDara-C is 50% at a median follow-up of 60 months in the DNR group and 45% after a median follow-up of 17 months in the IDA group. Whether the advantage of the superior response rate in the IDA-treated patients may be lost during HDara-C consolidation treatment due to in creased toxicity remains to be proven in larger trials.