Sequential mitoxantrone,daunorubicin, and cytosine arabinoside for patients with newly diagnosed acute myelocytic leukemia

Mitoxantrone (M) is a synthetic aminoanthraquinone with anti-leukemic activity in patients with daunorubicin (D) resistant acute leukemia. The Cancer and Leukemia Group B (CALGB) has undertaken a limited access pilot study in which M, 12 mg/m², over 30 min, daily for 3 days, and cytosine arabinoside (Ara-C), 100 mg/m²/day by constant infusion for 7 days were used for the induction of newly diagnosed patients with AML. Responding patients were consolidated with daunorubicin, 45 mg/m²/day for 3 days, and 7 days of Ara-C. After a second consolidation identical to induction, no further therapy was given. Twenty-nine patients with a median age of 50 years (range 18–72) were entered in the study; 18 were males and 11 females. Twenty-four (83%) patients achieved CR, 1 patient achieved a PR, and 4 died in induction from leukemia-related causes. Two patients died in CR from consolidation-related neutropenic sepsis and two additional patients died in CR. Of 24 patients, 7 remain disease-free at a median follow-up interval of 8 years. The regimen is active and well tolerated. The duration of disease-free survival in responding patients is consistent with that seen in similar regimens using intensification chemotherapy without prolonged maintenance. Am. J. Hematol. 56:214–218, 1997. © 1997 Wiley-Liss, Inc.     

The pharmacodynamic basis for the increased antileukaemic efficacy of cytosine arabinoside-based treatment regimens in acute myeloid leukaemia with a high proliferative activity

The current study was initiated to explore the mechanisms underlying the previously demonstrated association between the proliferative activity of leukaemic blasts and the response to cytosine arabinoside (AraC)-based therapy in de novo acute myeloid leukaemia (AML). The activity of key enzymes of AraC metabolism-deoxycytidine kinase (DCK), cytidine deaminase (DCD) and polymerase alpha (PolyA) were determined in blast cells from 33 patients. In addition, formation and retention of intracellular levels of AraC triphosphate (AraCTP) and DNA incorporation of AraC were measured, as was the proliferative activity of leukaemic blasts by [3H]-TdR incorporation before and after stimulation with granulocyte-macrophage colony-stimulating factor (GM-CSF) or granulocyte CSF (G-CSF) for 48 h. AraC incorporation into the DNA (median 0.60 pmol/105 cells) was significantly related to the proliferative activity of AML blasts (r = 0.74, P < 0.001). Similarly, priming with GM-CSF or G-CSF increased both the proliferative activity of AML blasts by a median of 1.84- and 1.64-fold, respectively, and the incorporation of AraC into the DNA (1.29- and 1.40-fold respectively). In contrast, no relationship was found between the endogenous proliferative activity (EPA) and enzyme activities regulating AraC activation (DCK; median 4.70 pmol/min/mg protein), inactivation (DCD; median 2.92 pmol/min/mg protein) or inhibitory effects (PolyA; median 1.50 pmol/min/mg protein), nor the formation or retention of AraCTP (median 306.1 ng/107 cell and 1.6 h respectively). When samples were grouped according to EPA (more than or less than the median), slowly proliferating specimens had a higher response to cytokine priming for proliferative activity and incorporation of AraC into DNA. Clinical data of 15 patients were available. Although all eight patients with a high endogenous proliferative activity reached complete remission, only four out of seven patients with a low proliferative activity responded, whereas the other three patients were non-responders (P = 0.077).     

Cytidine deaminase genotype and toxicity of cytosine arabinoside therapy in children with acute myeloid leukemia

Cytosine arabinoside (ara-C) is irreversibly deaminated to a non-toxic metabolite by cytidine deaminase (CDA). A common polymorphism, A79C, in the gene encoding cytidine deaminase ( CDA ) changes a lysine residue to glutamine resulting in decreased enzyme activity. CDA A79C genotypes were determined in 457 children with acute myeloid leukaemia (AML) treated on the Children's Cancer Group (CCG) 2941 and 2961 protocols and analyzed the impact of CDA genotype on therapy outcomes. Postinduction treatment-related mortality (TRM) was significantly elevated in children with the CC genotype (5-year TRM 17 ± 13% CC vs. 7 ± 4% AA, 5 ± 4% AC, P  = 0·05). This was more notable in children who received idarubicin, fludarabine, ara-C, and granulocyte colony-stimulating factor (IDA-FLAG; ara-C = 7590 mg/m²) (5-year TRM 24 ± 21% CC vs. 6 ± 6% AA, 6 ± 7% AC, P  = 0·07) as consolidation therapy compared to idarubicin, dexamethasone, cytarabine, thioguanine, etoposide and daunomycin (IDA-DCTER; ara-C = 800 mg/m²) (5-year TRM 15 ± 20% CC vs. 8 ± 6% AA, 4 ± 6% AC; P  = 0·29). Relapse-free survival was non-significantly increased in children with the CC genotype treated with IDA-FLAG (76 ± 20% CC vs. 59 ± 12% AA and 55 ± 14% AC; P  = 0·40). These data indicate that children with a low activity CDA genotype are at increased risk of TRM with ara-C based therapy for AML.     

Review of clinical and haematological response to low-dose cytosine arabinoside in acute myeloid leukaemia

15 patients with acute myeloid leukaemia (AML) were treated with low-dose cytosine arabinoside (LD ARA-C). 2 patients had complete remissions, which lasted for 8 and 3 months, and 5 patients had a partial remission. 46% of the patients thus responded to LD ARA-C. This included 1 responding patient who had not previously responded to therapy with 6-mercaptopurine, thioguanine, or vinblastine. The 2 patients with complete remission did not show LD ARA-C-induced hypoplasia of bone marrow, although 1 had hypoplastic AML before therapy. Leukaemic cells from 1 patient showed in vivo maturation from M1 to M3 after LD ARA-C treatment. The present results, together with the published data, indicate that: a. LD ARA-C treatment, although it may have some toxic effects, is an effective treatment for some patients with AML, especially those with hypoplastic AML; b. Response to LD ARA-C can be obtained after one or several courses of treatment; c. LD ARA-C-induced remissions are sometimes obtained even in patients who fail in more conventional treatments; d. LD ARA-C-induced remissions can be achieved without bone marrow hypoplasia, and induction of hypoplasia by itself does not always result in complete remission; e. LD ARA-C can induce in vivo maturation of leukaemic cells. It is suggested that induction of remission in AML patients by LD ARA-C may result from either differentiation of leukaemic blast cells, cytotoxicity to leukaemic blasts, or both mechanisms acting together.     

Low dose cytosine arabinoside in acute myeloid leukemia: remission is not due to differentiation induction

A patient with acute nonlymphoblastic leukemia (FAB M4), showing a near tetraploid chromosome complement on his marrow cells, was treated with low dose cytosine arabinoside and achieved remission. During remission the near tetraploid marrow chromosome complement disappeared and reappeared upon relapse of leukemia. These findings are interpreted as evidence against differentiation induction in the leukemic cell line as a mechanism for remission of the disease in this patient.     

Low dose cytosine arabinoside in refractory anemia with excess of blasts in transformation

Summary Myelodysplastic syndromes (MDS) are heterogeneous diseases. Patients with blast counts of more than 20% of nucleated bone marrow cells have a high risk of short survival. We treated six patients with refractory anemia with excess of blast in transformation (RAEBiT) with low dose cytosine arabinoside (LD Ara-C). We had one partial remission (PR), surviving 16 weeks and two complete remissions (CR), surviving 22 and 55+ months. Myelosupression was dominant in all patients, but was not as serious as with conventional remission-induction treatments for leukemias. Bone marrow aplasia occurred in all responding patients, but a differentiation effect is possible too. Maintenance therapy with LD Ara-C may be important for the two long-lasting CR.     

FLAG (fludarabine + cytosine arabinoside + G-CSF) induces complete remission in acute-phase chronic myeloid leukaemia: a case report

Summary The adenine nucleoside analogue fludarabine phosphate in combination with cytosine-arabinoside (Ara-C) and granulocyte-colony stimulating factor (G-CSF) has recently proved effective in the treatment of poor-prognosis acute non-lymphoid leukaemia. We used this triple combination in a case of Ph1 + chronic myeloid leukaemia (CML) unresponsive to alpha interferon that had progressed to acute phase after 5 months of treatment with 6-mercaptopurine plus hydroxyurea. The patient was treated with four courses of fludarabine 30 mg/m²+ Ara-C 2 g/m² (days 1–5) and GCSF (from day 0 to polymorphonuclear (PMN) recovery). Bone marrow blasts decreased from 80% to less than 5%, and karyotyping showed a progressive clearance of Ph1⁺ metaphases (from 100% to 9% after the fourth course). The patient is presently receiving autologous bone marrow transplantation (ABMT). This therapeutic success in a patient for whom conventional treatment would usually be ineffective makes this combination worthy of further studies, in view of its wider use as a preparative regimen to ABMT in CML.     

High-dose cytosine arabinoside and idarubicin treatment of chronic myeloid leukemia in myeloid blast crisis

Chronic myeloid leukemia in myeloid blast crisis (CML-MBC) is highly resistant to standard induction chemotherapy regimens. Anecdotal results from previous clinical trials support the concept of dose escalation in patients with CML-MBC. Eight patients with CML-MBC were treated with cytosine arabinoside (Ara-C) 1.5-3.0 g/m2 intravenously over 1 hr every 12 hr for 12 doses and idarubicin 12 mg/m2 intravenously daily for 3 days. Sixteen previous reports describing the use of Ara-C-based chemotherapy regimens in patients with CML-MBC were also reviewed. Our patients' median age was 62 years (range, 42-69 years). One patient achieved complete hematologic remission (95% confidence interval, 0.3%, 53%). The median survival for our patients was 7.3 months. These results were not different from previous published reports using Ara-C-based chemotherapy regimens to treat CML-MBC. In summary, the combination of high-dose Ara-C and idarubicin did not improve the overall prognosis of patients with CML-MBC. Innovative approaches need to be explored for this patient population.     

Behenoyl cytosine arabinoside, aclacinomycin A, 6-mercaptopurine, and prednisolone combination therapy for acute non-lymphocytic leukaemia in adults

38 consecutive, previously untreated adult patients with acute non-lymphocytic leukaemia (ANLL) were treated with BHAC-AMP (N4-behenoyl-1-beta-D-arabinofuranosyl-cytosine, aclacinomycin A, 6-mercaptopurine, and prednisolone) therapy between March 1980 and February 1985. 25 patients (65.8%) achieved complete remission (CR). Median CR duration and median survival of patients who achieved CR were 14, and 24 months, respectively. The Kaplan-Meier analysis revealed a probability for remaining in CR of 18.0% at 5 years. Analysis of failure cases revealed that most of them were due to resistant disease. Major toxicities were infection, diarrhoea, liver dysfunction, nausea and vomiting but these were acceptable. The results indicate that BHAC-AMP therapy is comparable to the regimen with daunorubicin and cytosine arabinoside and a further clinical trial is necessary for previously untreated adult patients with ANNL.     

Results of induction and consolidation treatment with intermediate and high-dose cytosine arabinoside and m-Amsa of patients with poor-risk acute myelogenous leukaemia

50 patients (aged 18-58 years) with acute myelogenous leukaemia after a preleukaemic phase (n = 14), acute myelogenous leukaemia that previously failed to respond to conventional chemotherapy (n = 9) or relapsed disease (n = 27) were given remission induction therapy consisting of cytosine arabinoside (1 g/m2 q 12 h x 12) and m-Amsa (115 mg/m2 for 1 or 3 days). Overall, 27 patients (54%) achieved complete remission. The complete remission rate for patients with acute myelogenous leukaemia after a preleukaemic phase (7/14) and those with primary refractory or relapsed leukaemia (20/36) seems superior to that obtained with conventional remission-induction therapy. 12 patients received 1-3 courses of consolidation chemotherapy with cytosine arabinoside (3 g/m2 q 12 h x 8) and m-Amsa (115 mg/m2 for 1 d). 3 of them subsequently underwent autologous bone marrow transplantation. The median duration of remission for the remaining 9 patients was 8 months. 11 patients did not receive consolidation therapy; their median duration of remission was 3 months. The difference between the two groups was not significant. 4 patients underwent allogeneic bone marrow transplantation after achievement of complete remission. The impact of high-dose cytosine arabinoside consolidation chemotherapy on poor-risk acute myelogenous leukaemia remains unclear.     

Structural and functional analysis of the cytidine deaminase gene in patients with acute myeloid leukaemia

Gene transfer of the cytidine deaminase (CDD) cDNA has recently been shown to induce cellular resistance to cytarabine (AraC) in vitro . To investigate the role for CDD in acute myeloid leukaemia (AML) we analysed the CDD activity and CDD gene structure in blast material from well-defined patients with untreated and AraC refractory (RF) AML. Median CDD activity in previously untreated AML was significantly lower than in RF-AML blasts ( P  = 0.015) and was significantly lower in patients with complete remission than with blast persistence following induction chemotherapy ( P  = 0.043). Structural investigation of the CDD gene by Southern analyses and RT-PCR showed no detectable aberrations. Sequence analysis of the CDD cDNA from nine RF-AML patients showed inconsistent aberrations in three patients. Semiquantitative assessment of CDD mRNA expression revealed a significant correlation with CDD activity. In conclusion, concordant with another recent study our data suggest a correlation of pretherapeutic CDD activity with induction treatment response. Besides the previously described prognostic impact of mdr1 expression, this result could be useful for the development of risk-adapted AML treatment strategies and warrants further studies of CDD activity in well-defined cohorts of AML patients and of the mechanisms involved in the regulation of CDD activity.     

A role for paclitaxel in the combination chemotherapy of acute myeloblastic leukaemia: preclinical cell culture studies

Paclitaxel dose responses in culture have been investigated alone and in association with cytosine arabinoside (ARA-C) and all- trans retinoic acid (ATRA), with the objective of identifying a role for paclitaxel in the treatment of acute myeloblastic leukaemia (AML). Initial studies were done to determine if paclitaxel dose responses of AML blast cell precursors were altered by regulatory compounds known to modify the dose responses of ARA-C. In contrast to ARA-C, paclitaxel dose responses were independent of cell culture method, the growth factors G-CSF and GM-CSF, and the ligands all- trans retinoic acid (ATRA) and hydrocortisone. Most blast cell populations were sensitive to paclitaxel; compared with normal marrow progenitors the dose responses were markedly heterogenous with some more, and others less, sensitive. Remission marrow progenitor paclitaxel responses resembled those of AML blasts in heterogeneity. The cell culture model tested the effect of paclitaxel and ATRA on the ARA-C dose responses of OCI/AML-5: paclitaxel exposure was either before or after ARA-C to test for an effect of schedule; ATRA was added to the MEC cultures after paclitaxel and ARA-C. Repeat experiments were done to test three dose levels each of paclitaxel and ATRA. When paclitaxel was given after ARA-C, synergism was found for all but one of the dose combinations tested; only three examples of synergy were seen when paclitaxel preceded ARA-C. The studies justify trials combining ARA-C, paclitaxel and ATRA using a schedule suggested by the cell culture findings.     

Epirubicin and cytosine arabinoside for the induction therapy of childhood acute nonlymphocytic leukemia.

Epirubicin, a new anthracycline, was used in combination with cytosine arabinoside for the induction therapy of de novo acute nonlymphocytic leukemia in childhood. The treatment consisted of epirubicin 20 mg/m2/day for 3 days and cytosine arabinoside 100 mg/m2/day for 7 days. The treatment could be repeated every 3 weeks. Remission induction rate was 80% (20/25). Moreover, in 13 patients, the remissions were obtained after a single course. In general, the side effects of epirubicin and cytosine arabinoside were tolerable. However, the main causes of all the three deaths were infections. Our study suggests that epirubicin is acceptable and effective for the induction therapy for de novo acute nonlymphocytic leukemia in childhood.     

High-dose cytosine arabinoside and daunorubicin postremission therapy in adults with de novo acute myeloid leukemia

A total of 149 consecutive de novo AML patients aged 50 years or less (median age = 37 years) were enrolled in this prospective multicenter trial initiated in May 1985. All patients received the same induction and early consolidation therapy with daunorubicin (DNR), cytosine arabinoside (Ara-C), and etoposide (DAV). High-dose Ara-C/DNR therapy included Ara-C at 3 g/m², in 12 doses (HD-Ara-C/DNR I) and eight doses (HD-Ara-C/DNR II), followed by DNR 30 mg/m² for 3 days. A complete remission (CR) was achieved in 104 (70%) patients; 61 complete responders received at least one cycle with HD-Ara-C/DNR. If those patients who were transplanted in first CR (n=26), were not considered, the median relapsefree-survival (MRFS) of the remaining 78 patients was 15 months, with a probability of relapse-free survival (RFS) at 116 months of 30% (95% CI, 20–40%) after a median follow-up of 95 months. The MRFS of the HD-Ara-C/DNR consolidated patients was 25 months, with a probability of RFS at 116 months of 37% (95% CI, 24–50%). If all patients who were transplanted (n=44) were not considered, the median survival time (MST) was 18 months with a probability of being alive at 118 months of 24% (95% CI, 16–33%). MST of the HD-Ara-C/DNR consolidated patients was 58 months with a survival probability of 46% (95% CI, 31–60%) at 118 months. Prognostic factor analysis did not reveal any significant influence of age, sex, FAB subtype, white blood cell count, hemoglobin level, thrombocyte count, LDH, or response to the first induction course on RFS of the HD-Ara-C/DNR consolidated patients. In summary, HD-Ara-C/DNR consolidation can improve the long-term outcome of a subgroup of de novo AML patients. Further improvement of the outcome seems to depend on the identification of patients with an inferior outcome under that strategy who might benefit from alternative treatment strategies.     

Assessment of caspase activity as a possible prognostic factor in acute myeloid leukaemia

Caspases are one of the key effector molecules in apoptosis. Caspase-3 activity (identified by cleavage of the peptide DEVD) was analysed in bone marrow blasts (minimum 70%) from 45 acute myeloid leukaemia (AML) patients. 12 patients (25%) exhibited high levels of specific DEVDase activity. These blast cells, despite having activated caspase-3, displayed none of the classical caspase-dependent morphological characteristics of apoptosis, such as degradation of DNA fragmentation factor 45, DNA fragmentation, and appeared to be more resistant to drug-induced apoptosis. Our results suggest that in these AML cells, resistance to apoptosis occurred downstream of caspase-3 activation.     

Mitozantrone and cytosine arabinoside as first-line therapy in elderly patients with acute myeloid leukaemia

We have prospectively evaluated a regimen of mitozantrone and cytosine arabinoside (Ara-C) as first-line therapy in elderly patients with acute myeloid leukaemia (AML). One hundred and four patients with a median age of 68 (range 60-81) were studied, in whom 86 had de-novo AML, and 18 had preceding myelodysplasia or secondary AML. Complete remission was achieved in 64% of de-novo cases, in 28% of MDS/secondary cases, and in 58% overall. The incidence of early death within 28 d of chemotherapy was 11%. The median disease-free survival (DFS) was 11 months with an actuarial DFS of 15% at 43 months. The median overall survival was 9 months with an actuarial survival of 10% at 44 months. The incidence of non-haematological toxicity was acceptably low, and usually of mild to moderate severity. Quality of life was improved, or unchanged, in 90% of responders. We conclude that mitozantrone and ara-C is an effective and well-tolerated regimen which produces high remission rates in elderly patients with AML.     

Expansion of cytotoxic effectors with lytic activity against autologous blasts from acute myeloid leukaemia patients in complete haematological remission

New therapeutic approaches are needed to improve the cure rates in acute myeloid leukaemia (AML). The present study was designed to investigate whether: (1) cytotoxic lymphocytes could be expanded from AML patients in complete remission; (2) their signal transduction machinery was preserved; (3) these cells were capable of producing cytokines involved in the cytolytic process; and (4) these cells showed cytotoxic activity against allogeneic and autologous blasts. By co-culturing blood mononuclear cells with feeder cells, we obtained an average 5.3-fold increase in the total cell number and a 35-fold increase in natural killer (NK) cells. Expression of the zeta chain and of tyrosine kinases of the Src and Syk-ZAP families involved in the triggering of NK functions was analysed on expanded cells. The results demonstrated a signal transduction apparatus preserved and quantitatively similar to that of normal donors. After phorbol myristate acetate and ionomicin stimulation, the ability of expanded cells to produce interferon gamma and tumour necrosis factor alpha was documented. Patients' expanded cells showed a cytotoxic activity against target lines and allogeneic blasts which was similar to that of normal donors. Purification experiments indicated that the NK cell fraction was responsible for most of the lytic effect. More significantly, these cells also exerted a lytic effect against autologous blasts that could be further enhanced following incubation with low-dose interleukin 2. These findings document the possibility of expanding cytotoxic effectors with preserved signal transduction machinery and autologous killing capacity from AML patients in remission, and suggest a new potential immunotherapeutic strategy for the management of early disease recurrence or of residual disease.