Induction therapy for acute myelogenous leukemia in patients over 60 years with intermediate-dose cytosine arabinoside, mitoxantrone and etoposide

Identification of prognostic subgroups among acute myeloid leukemia patients with intermediate risk cytogenetics using a flow-cytometry-based assessment of ABC-transporter function

BACKGROUND

A median fluorescence intensity ratio (MFIR) which measures the efflux of mitoxantrone (an ATP Binding Cassette (ABC) transporter substrate) with and without ABC transporter inhibition correlates with expression of MDR1 and BCRP in acute myeloid leukemia (AML) blasts.

METHODS

This study evaluates the impacts of the MFIR on AML outcomes and its interaction with detection of the FLT3 ITD.

RESULTS

Among 200 newly diagnosed AML patients, an MFIR of ≥ 1.9 (MFIR+) was detected in 60 (30%) leukemic blast samples. In multivariate analysis, MFIR was an independent prognostic factor for response to induction chemotherapy (OR=7.2, P<0.00001), DFS (HR=2.3, P=0.004) and OS (HR=2.2, P=0.0005) with the main effect being in the 141 patients with intermediate risk cytogenetics. Among intermediate risk cytogenetics patients: MFIR+ outcomes were similar to unfavorable cytogenetic risk (CR, 53% vs. 52%, P=1.0; OS, 11 vs. 9 months, P=0.79). MFIR status can further stratify the prognostic risk for patients with or without FLT3 ITD mutation.

CONCLUSIONS

MFIR has value in predicting outcomes including DFS and OS as well as induction failure. This is particularly true for patients with intermediate risk cytogenetics and when combined with assessment for the FLT3-ITD mutation.

Granulocyte-macrophage colony-stimulating factor to increase efficacy of mitoxantrone, etoposide and cytarabine in previously untreated elderly patients with acute myeloid leukaemia: a Swedish multicentre randomized trial

A total of 110 patients, aged 64 years or over, with de novo acute myeloid leukaemia (AML) and white blood cell counts <50 x 109/l were treated with 3 d of cytarabine 1 g/m2 twice daily, mitoxantrone 12 mg/m2 and etoposide 200 mg/m2, randomized with or without the addition of granulocyte-macrophage colony-stimulating factor (GM-CSF) 200 microg/m2. The primary aim was to evaluate the effect of GM-CSF on the remission rate. Secondary aims included comparison of duration of remission, survival and infectious complications and the impact of maintenance therapy with thioguanine. Complete remission (CR) was achieved by 64% of patients without GM-CSF, and by 65% of patients who received GM-CSF, the median remission duration was 13 vs. 6 months, the median overall survival (OS) was 14 vs. 9 months, the mean time to neutrophil recovery was 25 vs. 17 d (P = 0.03) and the number of positive blood cultures was 46 vs. 39 (P = 0.05) respectively. The impact of thioguanine remains unanswered since only 30 patients remained in CR after consolidation therapy. We conclude that induction therapy is feasible with acceptable toxicity in elderly patients with AML, albeit with a high relapse rate and short OS. GM-CSF prior to, and in combination with, induction treatment reduced the time to neutrophil recovery and the number of neutropenic septicaemia cases but did not improve the OS of AML in the elderly.

Mitoxantrone, Etoposide, and Cytarabine (MEC) Regimen for Relapsed or Refractory Acute Myelogenous Leukemia

The increasing complexity of cancer chemotherapy makes it mandatory that pharmacists be familiar with these highly toxic agents. This column focuses on the commercially available and investigational agents used to treat malignant diseases, reviewing issues related to the preparation, dispensing, and administration of cancer chemotherapy.

Chemotherapy for acute myelogenous leukemia in the elderly with cytarabine, mitoxantrone, and granulocyte-macrophage colony-stimulating factor

Remission induction chemotherapy for acute myelogenous leukemia typically combines cytarabine with an anthracycline or anthracycline derivative. To date, no specific combination has emerged as more efficacious than any other. To reduce toxicity and shorten the duration of neutropenia, hematopoietic growth factors are often added to the chemotherapy regimen, especially in elderly patients. In all prospective, randomized, growth factor trials to date, daunorubicin has been the drug selected for combination with cytarabine. We hypothesized that mitoxantrone might be as efficacious in this patient population with perhaps less toxicity when combined with granulocyte-macrophage colony-stimulating factor (GM-CSF). Patients older than age 55 years with a diagnosis of either de novo or secondary, untreated acute myelogenous leukemia were eligible for this clinical trial. Eligible patients were treated with cytarabine 100 mg/m2 infused as a continuous infusion daily for 7 days and mitoxantrone 12 mg/m2 bolus intravenously for the first 3 days of cytarabine. A second cycle of chemotherapy was administered on the fourteenth day of treatment if marrow aplasia was not achieved with the first cycle. Once aplasia was achieved, GM-CSF 250 microg/m2 was given subcutaneously daily until neutrophil recovery. Those patients who achieved complete remission were treated with two cycles of intermediate-dose cytarabine (400 mg/m2 daily for 5 days) and with GM-CSF as consolidation therapy. Of the 30 patients treated, the median age was 69 years (range: 55-76 years) and 18 patients were older than 65 years of age. Seven (23%) patients had secondary acute leukemia and 12 (40%) had poor-risk cytogenetics. Nineteen (63%) achieved a complete remission. Eleven patients were either refractory to treatment or died during their treatment. The toxicity encountered was no more than that reported in similar studies using daunorubicin in combination with cytarabine. Long-term survival was poor, with a median disease-free survival of only 8.1 months in patients who achieved complete remission. In this elderly population of patients with high-risk acute myelogenous leukemia, this combination of cytarabine, mitoxantrone, and GM-CSF resulted in an adequate remission rate with acceptable toxicity. Long-term survival, however, was poor and innovative treatment approaches to maintain remission are needed.

Bone marrow transplantation for adults with acute leukaemia and 11q23 chromosomal abnormalities

Adults with acute leukaemia and abnormalities of chromosome 11q23 have a poor prognosis when treated with conventional chemotherapy. To determine whether more intensive therapy can improve outcome for patients with this karyotypic finding, a retrospective analysis of all patients with acute leukaemia and 11q23 abnormalities treated at our centre was performed. 12 patients were treated with conventional chemotherapy alone (CC); 20 patients received high-dose chemo/radiotherapy (HDCT) with autologous (seven patients) or allogeneic (13 patients) bone marrow transplantation (BMT). The treatment-related mortality was 25% [95% Confidence Interval (CI) 7-69%] for the CC group and 46% (CI 25-73%) for the BMT group (P = 0.69). Cumulative risk of leukaemia progression was 89% (CI 61-100%) in the CC patients and 38% (CI 12-69%) in the BMT patients (P = 0.001). The 2-year event-free survival for patients treated with CC was 8% (CI 0-31%) and for patients receiving HDCT and BMT was 34% (CI 14-54%) (P = 0.03). These results confirm that conventional chemotherapy is rarely curative for adults with acute leukaemia and 11q23 abnormalities but that HDCT with BMT can result in long-term survival in a significant proportion of patients.

Induction failure in de novo acute myelogenous leukemia is associated with expression of high levels of CD34 antigen by the leukemic blasts

The prognostic significance of CD34 antigen expression in acute myelogenous leukemia (AML) is controversial. Most studies to date have reported on CD34 positivity and not the level of antigen present. In this study of 62 patients with de novo AML, 48 (77%) patients were CD34+ in varying levels (0-85 mean channels of fluorescence (MCF)). Forty seven of 62 were treated with combination chemotherapy and 39 (83%) of them achieved complete remission (CR). Patients with CD34- blasts were more likely to achieve CR; however, this trend was not statistically significant (p = .11). On the other hand, patients with higher levels of CD34 antigen on the blasts were less likely to attain CR (p < 0.001, multivariate analysis). The patients who achieved CR expressed lower levels of CD34 (0-57; median 9 MCF) as compared to those who did not achieve CR (15-85; median 30 MCF). Of the other antigens tested, partial or complete absence of CD33 (CD33 absent in > or =25% blasts) correlated with failure to achieve CR (p = 0.0029). These results are in keeping with the hypothesis that more primitive AML blasts with high levels of CD34 are chemoresistant.

Long-term outcome of high-dose cytarabine-based consolidation chemotherapy for older patients with acute myelogenous leukemia

Despite reports of improved response and leukemia-free survival for adults with acute myelogenous leukemia, advanced age remains a significant adverse prognostic factor for both response to induction therapy and prolonged leukemia-free survival. In addition to a high incidence of treatment-related complications, older patients may have other disease characteristics which predict for brief remission duration despite intensive consolidation chemotherapy. We analyzed the long-term results of high-dose cytarabine-anthracycline consolidation chemotherapy in older patients and examined the effect of major prognostic factors including a history of myelodysplasia, increased age, and cytogenetics. One hundred and ten patients age > or = 60 with newly diagnosed acute myelogenous leukemia were enrolled on three sequential studies conducted from 1982 to 1996. Fifty-six patients (51%) achieved a complete remission and were eligible for high-dose cytarabine-based consolidation chemotherapy administered in two to three courses. After a median follow-up of surviving patients for seventeen months, twelve patients remain alive with eleven in continued remission. Median remission duration for all eligible patients is nine months and the actuarial leukemia-free survival is 14 +/- 10%. Toxicity of consolidation therapy included treatment-related death in six patients and serious neurotoxicity in five. When compared to younger patients, patients over age 60 sustained a much higher risk of relapse despite successfully completing intensive consolidation therapy, regardless of whether other adverse prognostic features were present. Advanced age in acute myelogenous leukemia is associated with a significantly higher risk of relapse unmodified by the presence or absence of other adverse disease characteristics. Although older patients tolerated intensive therapy designed to address the high risk of relapse, there was no apparent benefit of high-dose cytarabine consolidation alone as post-remission treatment for acute myelogenous leukemia in this population.

Acute monocytic leukemia: a single institution experience

Using strict FAB criteria, 39 cases of monocytic leukemia were identified in 463 consecutive cases of AML. Patients had a median age of 49 with no sex predominance. Extramedullary disease and hyperleukocytosis were common (54% and 36% of patients respectively). Cytogenetic analysis was successful in 38 of 39 patients; 71% had a cytogenetic abnormality and 42% of these involved chromosome 11; 14 of 16 chromosome 11 abnormalities involved the region of 11q23. Non-chromosome 11 abnormalities tended to occur in older patients and to be associated with a lower platelet count; patients with the translocation 9;11 tended to have a lower white count and a higher incidence of therapy-related leukemia. 35 patients were treated with induction therapy including intensive chemotherapy (n = 33) and allogeneic BMT at presentation (n = 2). Patients who entered remission underwent consolidation chemotherapy, autologous BMT, or allogeneic BMT depending on policies at the time of diagnosis. Of 6 patients who underwent further intensive chemotherapy there is 1 long-term disease-free survivor. 3 of 8 patients undergoing autologous BMT and 2 of 3 patients undergoing allogeneic BMT are long-term disease-free survivors. We conclude that this specific subtype of AML, relatively rare when strict criteria are applied, is associated with unique biologic and clinical features and that the high relapse rate associated with conventional therapy makes new treatment approaches involving stem cell transplantation or immunomodulation necessary.

Low-dose cytosine arabinoside in patients with acute myeloid leukemia not eligible for standard chemotherapy

The results of treatment with low dose cytosine arabinoside (LDARA-C) in 131 AML patients ineligible for standard regimens were analyzed retrospectively. Eighty-seven were previously untreated, 25 were refractory to conventional chemotherapy and 19 were relapsed patients. The median age was 66 years (15-84). An antecedent hematological disorder (AHD) was documented in half of the patients. Overall, 22 (17%) achieved complete remission, 14 (11%) partial remission, 77 (59%) had resistant leukemia and 18 died during induction. Median disease free survival was 57 weeks and median survival, for the 87 previously untreated patients, was 22.5 weeks. The prognostic value of initial parameters was analyzed for response. Bone marrow cellularity was the only significant factor. We observed 33% vs 81% (p < 0.01) of responses in patients with normo-hypercellular and hypocellular marrow, respectively. Accordingly, there was a trend to more responses in patients with leukocyte counts of less than 10 x 10(9)/L. M4-M5 FAB subtypes were frequently resistant to LDARA-C, resulting in a lower response rate compared to M0-M2 (18% vs 32%). Other parameters, including age, sex, hemoglobin, platelet count, AHD and fever at diagnosis, had no prognostic value. Our findings suggest that LDARA-C may be an effective treatment for some patients who are not eligible for first line conventional chemotherapy. However, this schedule is not advised in patients with monocytic leukemia or those with an hypercellular marrow.

Mitoxantrone and cytosine arabinoside as treatment for acute myeloblastic leukemia in older patients

The majority of patients with acute myeloid leukemia (AML) are elderly, and their response to chemotherapy is poorer than that of younger patients. The combination of mitoxantrone (MTN) and cytosine arabinoside (Ara-C) is a possible alternative to an anthracycline/Ara-C combination for the treatment of AML in these patients. Of 52 older patients (> 59 years) referred over a 3.5-year period, 33 patients (age range 60-78 years, median 67 years) received MTN and Ara-C as therapy for newly diagnosed AML. MTN was administered at a dose of 12 mg/m2/day, intravenously, for 3 days (23 patients), or 10 mg/m2/day for 5 days (10 patients), and Ara-C at a dose of 100 mg/m2 twice daily, intravenously, for 7 days. Complete remission (CR) was achieved in 16/33 patients (48%). The median remission duration was 6 months (range 1-37 months). The median survival was 14 months for those who achieved CR compared with 9 months for those with resistant disease. Two patients remain in first CR after 13 and 37 months, but three patients died whilst receiving consolidation therapy. In selected elderly patients with AML, the combination of MTN and Ara-C provides an acceptable alternative to an anthracycline/Ara-C regimen, with a higher CR rate than historical controls. However, the CR rate and remission duration remain low compared with those of younger patients, supporting the need to investigate new approaches to treatment in this population.

Attenuated-dose idarubicin in acute myeloid leukaemia of the elderly: pharmacokinetic study and clinical results

AML in the elderly is characterized by intrinsic biological features implying an enhanced chemoresistance. Intensive chemotherapy should be the treatment of choice, but the standard doses could induce unacceptable rates of aplastic deaths. We evaluated the efficacy of an induction protocol with attenuated-dose idarubicin (IDA) 8 mg/m2 for 3 d plus cytarabine and etoposide in 26 AML patients aged > 60. 18 patients (69%) achieved CR, five (19%) were non-responders and three (12%) died during induction. To compare the pharmacokinetics of IDA between elderly and young patients, we assayed daily the serum level of the drug and of its metabolite (idarubicinol, IDAol) in a group of eight elderly patients who received a dose of 8 mg/m2 (group A) and in a group of nine younger AML patients treated with 12 mg/m2 (group B). The apparent terminal half-life of IDAol was significantly longer in the elderly than in the younger patients (mean half-life 59.7 h versus 41.4 h, P < 0.05). The values of the area under the serum concentration curve of IDAol indicated that the two patient groups received a very similar exposure to the drug despite the different doses. In conclusion, this protocol, based on attenuated doses of IDA, compares well with the results obtained previously in similar age-matched patient series.