High-dose idarubicin and busulphan as conditioning for autologous stem cell transplantation in acute myeloid leukemia: a feasibility study

Autologous stem cell transplantation for adult acute leukemia in 2015: time to rethink? Present status and future prospects

The use of autologous stem cell transplantation (ASCT) as consolidation therapy for adult patients with acute leukemia has declined over time. However, multiple randomized studies in the past have reported lower relapse rates after autologous transplantation compared with chemotherapy and lower non-relapse mortality rates compared with allogeneic transplantation. In addition, quality of life of long-term survivors is better after autologous transplantation than after allogeneic transplantation. Further, recent developments may improve outcomes of autograft recipients. These include the use of IV busulfan and the busulfan+melphalan combination, better detection of minimal residual disease (MRD) with molecular biology techniques, the introduction of targeted therapies and post-transplant maintenance therapy. Therefore, ASCT may nowadays be reconsidered for consolidation in the following patients if and when they reach a MRD-negative status: good- and at least intermediate-1 risk acute myelocytic leukemia in first CR, acute promyelocytic leukemia in second CR, Ph-positive acute lymphocytic leukemia. Conversely, patients with MRD-positive status or high-risk leukemia should not be considered for consolidation with ASCT.

High-dose idarubicin plus busulfan as conditioning regimen to autologous stem cell transplantation: promising post-remission therapy for acute myeloid leukemia in first complete remission?

The optimal post-remission therapy (PRT) for acute myeloid leukemia (AML) remains uncertain. We reported 32 AML patients in first complete remission (CR1) undergoing autologous hematopoietic stem cell transplantation (ASCT) with a characteristic conditioning regimen, termed I-Bu, based on high-dose idarubicin plus busulfan, which considerably strengthened antileukemic activity. Most patients were in better or intermediate-risk group except that cytogenetic or molecular risk information was missing for 18.7 % of the patients. Unpurged peripheral blood stem cells were used in all the cases. The adverse effects were mild and reversible. Only one case of transplant-related mortality was observed. All the patients in this study acquired hematopoietic reconstitution after ASCT. After a median follow-up of 30 (6-119) months, 24 patients (75.0 %) were alive in which 20 (62.5 %) patients were in continuous CR. There were 11 (34.4 %) patients who relapsed after HSCT. Cumulative relapse probability was about 40 % after 24 months. Median OS and DFS have not been reached. Patients in the better and intermediate-risk group had different clinical outcomes, but the differences were not statistically significant. ASCT with I-Bu regimen is possibly promising PRT for better and intermediate-risk AML patients in CR1.

Idarubicin-intensified BUCY2 regimens may lower relapse rate and improve survival in patients undergoing allo-SCT for high-risk hematological malignancies: a retrospective analysis

We conducted a retrospective study to evaluate the outcome of 94 consecutive patients with high-risk hematological malignancies who received allo-PBSCT, following idarubicin (IDA)-intensified BUCY2 (IDA-BUCY2) myeloablative conditioning regimens (n=53) and BUCY2 conditioning regimens (n=41). IDA 15 mg/m(2) once daily was administered by continuous infusion on days -11 to -9, followed by BU, 3.2 mg/kg in divided doses daily, on days -6 to -4, and i.v. injection of CY, 1.8 g/m(2) once daily on days -3 to -2 in the IDA-BUCY2 group. The relapse rate in patients in the IDA-BUCY2 and BUCY2-conditioning regimens group was 18.9 and 39%, respectively (P=0.030). There was no significant difference in terms of TRM. The cumulative probabilities of OS and disease-free survival at 2 years for patients conditioned with the IDA-BUCY2 and BUCY2 regimens were 65.3% vs 46.8% (P=0.038), and 63.5% vs 43.4% (P=0.025), respectively. Multivariate analysis showed that IDA-BUCY2 regimens and limited chronic GVHD were the only two factors resulting in improved survival and reduced relapse rate. This retrospective study suggests that IDA-intensified BUCY2 may be substituted for BUCY2 as conditioning regimen for patients with high-risk hematological malignancies.

High-dose idarubicin and busulphan as conditioning to autologous stem cell transplantation in adult patients with acute myeloid leukaemia

Between 30 and 50% of patients with acute myeloid leukaemia (AML) relapse after autologous stem cell transplantation (ASCT). One possibility of reducing the relapse rate could be the adoption of conditioning regimens specifically designed for AML. We report treatment results achieved with a new conditioning for ASCT, based on high-dose idarubicin (IDA) plus oral busulphan. Patients (n = 40) were conditioned with a regimen consisting of 3 d continuous intravenous infusion IDA at 20 mg/m2, followed by 4 d conventional dose oral busulphan. Unpurged peripheral blood stem cells were used in all cases. All patients had non-M3-AML and were in first complete remission (CR). The median number of CD34+ cells infused was 6.9 x 10(6)/l (2.6-24). No case of transplant-related mortality occurred. In all cases, left ventricular ejection fraction remained unmodified after ASCT. Thirty-three of 40 patients (82%) had grade 3-4 mucositis requiring total parenteral nutrition in all cases. After a median follow up for surviving patients of 32 months from ASCT, 30 patients (75%) are alive and 26 (65%) are in continuous CR. Our data show that a conditioning regimen based on high-dose IDA plus busulphan results in an encouraging reduction of the relapse rate after ASCT in AML.

Continuous infusion idarubicin and oral busulfan as conditioning for patients with acute myeloid leukemia aged over 60 years undergoing autologous stem cell transplantation

There is growing interest in autologous stem cell transplantation (ASCT) for elderly patients with acute myeloid leukemia (AML). While mortality and toxicity from ASCT have been reduced, relapse rate is still high. In a prospective study, we investigated the feasibility of a new conditioning regimen consisting of high-dose idarubicin plus busulfan in AML patients aged over 60 years undergoing ASCT. A total of 14 patients (median age: 64 years) received 2 days continuous infusion of idarubicin at 20 mg/m2/day, followed by 3 days of oral busulfan (4 mg/kg/day) as conditioning. No case of transplant-related mortality occurred. The median number of days to neutrophil ( > 0.5 x 10(9)/l) and platelet ( > 20 x 10(9)/l) recovery was 11 and 12, respectively. Cardiac toxicity was absent, while 12 patients (86%) had grade 3-4 mucositis. After a median follow-up of 9 months from ASCT, nine of 14 patients are alive in continuous complete remission (CR), four have relapsed at 3, 6, 8 and 9 months, and one died in CR1 from gastric cancer. Our data demonstrate the feasibility of a conditioning regimen based on high-dose idarubicin plus busulfan in elderly AML patients. Results concerning reduction of relapse rate need confirmation in a larger series with longer follow-up.

Unanswered questions in acute myeloid leukaemia

Acute myeloid leukaemia (AML) is a heterogeneous disease that presents with a range of morphological, cytogenetic, immunophenotypic, and biomolecular features. Over the past 20 years, application of new cytogenetic and molecular techniques has greatly improved knowledge of the pathophysiology of AML, resulting in new potential therapeutic applications. However, the results of current therapy are still unsatisfactory, especially in patients who have adverse prognostic factors at the time of diagnosis. Furthermore, some pivotal questions about the procedures of induction and postinduction therapy of AML remain unanswered, and substantial controversy exists on the optimum therapeutic approach for the disorder.

Autologous stem-cell transplantation for patients with acute myeloid leukemia aged over 60 yr

OBJECTIVES

Preliminary reports have suggested that autologous stem-cell transplantation (ASCT) is feasible in elderly patients with acute myeloid leukemia (AML). The objective of this study was to describe the disease characteristics and treatment results from a series of 22 elderly AML patients undergoing ASCT.

METHODS

The median age was 64 yr (range 61-71). Twenty patients were in first complete remission (CR1), two in CR2, and all were in performance status 0-1. The median interval between CR achievement and ACST was 3 months (range 2-5). In 20 cases peripheral blood stem cells were infused, in two bone marrow.

RESULTS

All patients had a successful engrafment. One patient (5%) died from transplant-related complications. The median number of days to granulocytes > 500 mm-3 and platelets > 20 000 mm-3 was 11(range 9-15) and 13 (range 9-20), respectively. Non-hematologic toxicity included WHO grade III-IV stomatitis in 32% patients and grade IV nausea and vomiting in one (4.5%). Seven patients had fever of unknown origin, while in 14 a documented infection was diagnosed. Median duration of hospitalization was 31 d (range 16-60).

CONCLUSIONS

After a median follow-up of 12 months from ASCT, nine patients are alive in continuous CR and 13 died from AML relapse. Median survival from diagnosis and disease-free survival (DFS) was 19 and 14 months, respectively. Our data show that ASCT with a standard conditioning regimen is feasible in AML patients aged more than 60 yr. Toxicity and hemopoietic recovery do not substantially differ from those observed in young adults. DFS and overall survival (OS) duration are encouraging, but a longer follow up is needed on a larger series of patients.

De novo acute myeloid leukemia with multilineage dysplasia: treatment results and prognostic evaluation from a series of 44 patients treated with fludarabine, cytarabine and G-CSF (FLAG)

OBJECTIVES

To evaluate therapeutic results and prognostic factors from a series of 44 patients affected by de novo acute myeloid leukemia with multilineage dysplasia (MD-AML), treated with the combination of fludarabine, cytarabine and G-CSF (FLAG).

METHODS

Forty-four patients with de novo MD-AML were treated with the FLAG regimen. The median age was 61 yr (range 31-75 yr). Induction therapy consisted of the FLAG regimen; consolidation included idarubicin plus cytarabine. Patients with a compatible donor and aged less than 55 yr were programmed to receive allogeneic bone marrow transplantation (BMT), while in those without a donor and aged less than 65 yr autologous transplantation with peripheral blood stem cells mobilized by a consolidation regimen plus G-CSF was planned. Bone marrow harvest was performed in poor mobilizers.

RESULTS

Complete remission (CR) was achieved in 28 out of 44 patients (64%). Death in induction occurred in four patients (9%), while 12 patients (27%) were resistant to FLAG. Toxicity of consolidation was negligible. Most patients aged less than 60 yr and achieving CR were eligible for transplantation procedures, the main reason of exclusion being early relapse. Median overall survival and disease free survival were 16 and 22 months, respectively. Unfavorable cytogenetics was the only parameter significantly related to inferior clinical outcome following multivariate analysis.

CONCLUSION

Multilineage dysplasia per se is not an adverse prognostic factor in AML patients treated with the FLAG regimen. Favorable results are obtained in patients with intermediate karyotype, while in those with adverse cytogenetics new approaches are clearly needed. The toxicity of the regimen is also acceptable in the elderly, and following induction/consolidation, most patients may be submitted to transplantation procedures.