Phase-II trial of idarubicin, fludarabine, cytosine arabinoside, and filgrastim (Ida-FLAG) for treatment of refractory, relapsed, and secondary AML

Outcome of patients with relapsed or refractory acute myeloid leukemia treated with Mito-FLAG salvage chemotherapy

PURPOSE

Curative intended treatment is challenging in patients with relapsed or refractory acute myeloid leukemia (r/r AML) and associated with a dismal prognosis for long-term survival. Despite novel treatment options, the majority of patients are treated with chemotherapy-based regimens. Although widely used, little data exist on the combination of fludarabine, cytarabine, granulocyte colony stimulating factor (FLAG) and mitoxantrone as salvage strategy for r/r AML.

MATERIALS AND METHODS

Sixty-six patients receiving Mito-FLAG for r/r AML treated at a German tertiary care center between 2009 and 2019 were analyzed with regard to response rates, survival and safety profile.

RESULTS

Overall response rate was 75.8% with 56.1% of patients achieving complete remission (CR) and 19.7% partial remission (PR). After a median follow-up of 54 months, median overall survival (OS) was 13 months. Patients transitioned to allogeneic hematopoietic stem cell transplantation (alloHSCT) (75.8%) showed a significant improvement in OS with a median OS of 17 (95% CI 8.5-25.4) months vs 3 (95% CI 1.7-4.3) months (p < 0.001). 30- and 60-day mortality rates for all patients after the initial cycle of Mito-FLAG were 4.5% and 7.6%, respectively.

CONCLUSION

The Mito-FLAG salvage protocol represents an effective and feasible treatment regimen for r/r AML. Importantly, a high rate of transition to successful alloHSCT with the aim of long-term disease-free survival has been shown.

A phase II study of bisantrene in patients with relapsed/refractory acute myeloid leukemia

OBJECTIVES

To determine the current role of bisantrene, an anthracene with anthracycline-like activity which was shown in earlier studies to be effective therapy in relapsed/refractory acute myeloid leukemia with no discernible cardiotoxicity, in the treatment of patients with R/R AML.

METHODS

This phase 2, single-center study (NCT03820908) enrolled adult R/R AML to receive bisantrene (250 mg/m² daily for 7 days) which was administered via an intravenous infusion over 2 hours on days 1-7. Disease assessment included routine blood work and bone marrow studies.

RESULTS

In all, 10 patients were enrolled with a median of 3 lines of prior therapy including seven patients who had relapsed following allogeneic stem cell transplantation. The most frequently reported grade ≥3 treatment-attributed hematologic AE was thrombocytopenia, whereas the most frequently reported grade ≥3 treatment-attributed non-hematologic AE was mucositis. Of the 10 patients, one (10%) achieved a complete remission and three patients achieved a partial remission resulting in an overall response rate of 40%. Next-generation sequencing of patient samples identified a wide array of mutations associated with activated signaling, splicing, and epigenetic modification.

CONCLUSIONS

In view of the observed low toxicity, a follow-up study combining bisantrene with complementary anti-leukemic therapy is planned.

Comparison of salvage chemotherapy regimens and prognostic significance of minimal residual disease in relapsed/refractory acute myeloid leukemia

We compared the outcomes of salvage chemotherapy in 146 patients with relapsed (57.5%) or refractory (42.5%) AML who received CLAG-M (51%), MEC (39%) or CLAG (10%). Minimal residual disease (MRD) was assessed by flow cytometry. Bivariate, Kaplan-Meier, and Cox regression analyses were conducted. Complete remission (CR) rate of 46% (CLAG-M 54% versus MEC/CLAG 40%, p = .045) was observed with MRD-negative CR of 33% (CLAG-M 39% versus MEC/CLAG 22%, p = .042). Median overall survival (OS) was 9.7 months; the longest OS occurred with CLAG-M (13.3, 95%CI 2.4-24.3) versus MEC (6.9, 95%CI 2.9-10.9) or CLAG (6.2, 95%CI 2.4-12.6) (p = .025). When adjusted for age, gender, relapsed/refractory AML, poor risk AML, MRD, chemotherapy and transplant, CLAG-M (HR 0.63, 95% CI 0.40-0.98, p = .042), MRD-negativity (HR 0.15, 95% CI 0.07-0.30, p < .001) and transplant (HR 0.22, 95% CI 0.13-0.39, p < .001) were associated with higher OS. Our findings confirm that CLAG-M is a reasonable salvage regimen for RR-AML followed by transplant.

Reassessing the role of high dose cytarabine and mitoxantrone in relapsed/refractory acute myeloid leukemia

A substantial segment of patients with acute myeloid leukemia (AML) will relapse following an initial response to induction therapy or will prove to be primary refractory. High-dose cytarabine and mitoxantrone (HiDAC/MITO) is an established salvage therapy for these patients. We studied all adult patients with relapsed/refractory (R/R) AML who were treated with HiDAC/MITO in our center between the years 2008-2017. To determine whether responding patients harbored a unique molecular signature, we performed targeted next-generation sequencing (NGS) on a subset of patients. The study cohort consisted of 172 patients with a median age of 54 years (range 18–77). The composite complete remission rate was 58%; 11 patients (6%) died during salvage therapy. Median survival was 11.4 months with a 1-year survival rate of 48%. In multivariate analysis favorable risk cytogenetics [Odds ratio (OR)=0.34, confidence interval (CI) 95%, 0.17–0.68; P = 0.002], and de-novo AML (OR = 0.4, CI 95%, 0.16–0.98; P = 0.047) were independently associated with a favorable response. Patients who attained a complete remission had a median survival of 43.7 months compared with 5.2 months for refractory patients (p < 0.0001). Neither the FLT3-ITD and NPM1 mutational status nor the indication for salvage therapy significantly impacted on the response to HiDAC/MITO salvage. NGS analysis identified 20 different mutations across the myeloid gene spectrum with a distinct TP53 signature detected in non-responding patients. HiDAC/MITO is an effective salvage regimen in R/R AML, however patients with adverse cytogenetics or secondary disease may not benefit as much from this approach.

Salvage treatment for refractory or relapsed acute myeloid leukemia: a 10-year single-center experience

OBJECTIVES

The outcomes of refractory and relapsed acute myeloid leukemia (AML) patients in developing countries are underreported, even though the similar classic regimens are widely used.

METHODS

We conducted a retrospective comparison of "MEC" (mitoxantrone, etoposide, and cytarabine) and "FLAG-IDA" (fludarabine, cytarabine, idarubicin, and filgrastim) in adults with first relapse or refractory AML.

RESULTS

In total, 60 patients were included, of which 28 patients received MEC and 32 received FLAG-IDA. A complete response (CR) rate of 48.3% was observed. Of the included patients, 16 (27%) died before undergoing bone marrow assessment. No statiscally significant difference in CR rate was found between the two protocols (p=0.447). The median survival in the total cohort was 4 months, with a 3-year overall survival (OS) rate of 9.7%. In a multivariable model including age, fms-like tyrosine kinase 3 (FLT3) status, and stem-cell transplantation (SCT), only the last two indicators remained significant: FLT3-ITD mutation (hazard ratio [HR]=4.6, p<0.001) and SCT (HR=0.43, p=0.01).

CONCLUSION

In our analysis, there were no significant differences between the chosen regimens. High rates of early toxicity were found, emphasizing the role of supportive care and judicious selection of patients who are eligible for intensive salvage therapy in this setting. The FLT3-ITD mutation and SCT remained significant factors for survival in our study, in line with the results of previous studies.

Phase II study of FLAGM (fludarabine + high-dose cytarabine + granulocyte colony-stimulating factor + mitoxantrone) for relapsed or refractory acute myeloid leukemia

Given the poor prognosis of patients with relapsed/refractory acute myeloid leukemia (AML), better therapy is needed. Fludarabine enhances the efficacy of Ara-C (cytarabine) by increasing intracellular Ara-C-triphosphate. The FLAG (fludarabine, high-dose Ara-C, supported with granulocyte colony-stimulating factor) regimen has been tested for use in AML patients by other investigators. In the phase II study reported here, we evaluated the efficacy and toxicity of FLAGM therapy (FLAG with mitoxantrone), further intensified by adding mitoxantrone, based on the results of a phase I study by our group. The major endpoints were complete remission (CR) rate and early death. From June 2004 to February 2008, 41 patients (median age 52 years; range 18-64 years) were enrolled. Thirty (73% 95% CI 58-84%) patients achieved CR, which met the primary endpoint; there was a single case of early death from pneumonia. Two-year overall survival was 39.4% (95% CI 25.2-55.6%). Of those who achieved CR, 27 underwent allogeneic stem cell transplantation (SCT), and 12 SCT recipients showed long-term survival. Grade 3/4 non-hematological adverse events included infection (59%), nausea/vomiting (15%), diarrhea (7%), and elevated liver enzymes (7%). In conclusion, FLAGM is an effective and safe salvage therapy for patients with relapsed/refractory AML, and facilitated SCT for a large proportion of patients.

FLAG salvage therapy combined with idarubicin in relapsed/refractory acute myeloid leukemia

Acute myeloid leukemia (AML) is characterized by a high failure rate to achieve complete remission as well as high relapse rates that cause an emergent need for efficient and tolerable salvage therapies. The combination of FLAG with idarubicin (FLAG-Ida) is a widely used protocol. However, its efficacy has been analyzed in only a limited number of studies with majorly small patient cohorts. Here, we analyzed 132 patients with largely primary refractory or first-time relapsed AML treated according to the FLAG-Ida protocol. The overall complete remission rate (CR + CRi) was 56% with a median overall survival of 15 months (95% CI, 5.7-25.1). The median disease-free survival for CR/CRi-patients was not reached. The mortality rate on day 30 was 9% and increased on day 60 to 16%. Our results show in relapsed/refractory AML patients a high efficacy and compatibility for the FLAG-Ida regimen.

Treatment of relapsed/refractory acute myeloid leukaemia in adults

The prognosis of relapsed acute myeloid leukaemia (AML) is poor and treatment is challenging. While the most potent treatment modality for patients who achieve a complete remission after relapse is still allogeneic haematopoietic cell transplantation (allo-HCT), both transplant-related mortality and relapse rates are high and many patients are not candidates for this approach. After a few decades of relative stasis in this field, a large number of novel approaches have become available to tackle this highly fatal disease. This is mostly due to our improved understanding of disease pathogenesis (including targetable mutations) and the anti-leukaemia potential of the immune system. Several small-molecule inhibitors and immunotherapeutic options are being explored in clinical trials and many more are in pre-clinical phase. Future studies will focus on novel and mechanistically driven combinations, sequential treatments, and low-toxicity maintenance strategies. While cure of relapsed/refractory AML without allo-HCT is currently unlikely, treatments are becoming less toxic and remissions are lasting longer.

Fludarabine, cytarabine, granulocyte colony-stimulating factor and idarubicin for relapsed childhood acute myeloid leukemia

BACKGROUND

The combination of fludarabine (Flu), high-dose cytarabine (Ara-C) and granulocyte colony-stimulating factor (G-CSF; FLAG), with anthracyclines has become standard chemotherapy for refractory acute myeloid leukemia (AML) in European children and adults. To clarify the efficacy and the safety of FLAG-idarubicin (IDA) for children prospectively, we planned a multicenter phase II study (AML-R11) by the Japanese Pediatric Leukemia/Lymphoma Study Group.

METHODS

Patients with AML aged between 2 and 20 years old, who had the first bone marrow (BM) relapse or induction failure, were enrolled. The FLAG-IDA regimen consisted of Flu 30 mg/m² for 5 days, Ara-C 2 g/m² for 5 days, G-CSF (lenograstim) 5 μg/kg for 6 days and IDA 10 mg/m² for 3 days. The primary endpoint was remission rate after therapy.

RESULTS

Due to drug supply issues, the trial was suspended after the inclusion of seven eligible patients. There were six cases of early relapse within 1 year of the first remission. All seven patients completed the therapy and no early death was observed. Hematological toxicity was common, and one patient developed grade 4 non-hematological toxicity of bacterial meningitis. Although only one patient with late relapse achieved complete remission, minimal residual disease was positive on both flow cytometry and Wilms' tumor 1 mRNA. Two patients were alive in remission following hematopoietic stem cell transplantation, whereas the other five patients died of either the disease or treatment-related causes.

CONCLUSION

FLAG-IDA might be tolerable for children with refractory AML although the efficacy should be further investigated.

Cyclophosphamide combined with mitoxantrone and cytarabine is an effective salvage regimen for patients with acute myeloid leukemia who experienced primary induction failure or relapse

Salvage regimens containing mitoxantrone have been successfully used for the treatment of primary induction failure or relapsed acute myeloid leukemia. However, the combination of cyclophosphamide with mitoxantrone and cytarabine (MAC) has never been assessed in these patients. A total of 91 patients, including patients with primary induction failure (n=44) and relapsed (n=47), were treated with a salvage MAC regimen, which consisted of mitoxantrone, cytarabine and cyclophosphamide. The overall complete remission rate was 74.7 (68/91) and 72.7% (32/44) for primary induction failure, and 76.6% (36/47) for relapsed patients. The overall survival rate and disease-free survival rate were 72.1 and 59.7% at 1 year, 42.9 and 47.1% at 3 years, and 36.7 and 43.0% at 5 years, respectively. Only one patient succumbed to mortality during induction therapy. The toxicity level was acceptable. Therefore, the present study demonstrated that MAC is a highly effective and well-tolerated regimen for salvage in patients experiencing primary induction failure or relapse. This treatment significantly improved the prognosis.

Homoharringtonine in combination with cytarabine and aclarubicin in the treatment of refractory/relapsed acute myeloid leukemia: a single-center experience

To assess the efficacy and toxicity of HAA regimen (Homoharringtonine 4 mg/m(2)/day, days 1-3; cytarabine 150 mg/m(2)/day, days 1-7; aclarubicin 12 mg/m(2)/day, days 1-7) as a salvage therapy in the treatment of refractory and/or relapsed acute myeloid leukemia (AML), 46 patients with refractory and/or relapsed AML, median age 37 (16-65) years, participated in this clinical study. The median follow-up was 41 (10-86) months. Eighty percent of patients achieved complete remission (CR), and the first single course of re-induction HAA regimen resulted in CR rate of 76.1 %. The study protocol allowed two courses of induction. The CR rates of patients with favorable, intermediate and unfavorable cytogenetics were 90 %, 88.9 %, and 37.5 %, respectively. For all patients, the estimated 3-year overall survival (OS) rate was 42 %, and the estimated relapse free survival (RFS) at 3 years for the 36 CR cases was 49 %. The toxicities associated with HAA regimen were acceptable. HAA is a good choice in cases with refractory/relapsing AML for salvage chemotherapy, preferably with a high-efficacy and low-toxicity profile.

Older and new purine nucleoside analogs for patients with acute leukemias

Purine nucleoside analogs (PNAs) compose a class of cytotoxic drugs that have played an important role in the treatment of hematological neoplasms, especially lymphoid and myeloid malignancies. All PNA drugs have a chemical structure similar to adenosine or guanosine, and they have similar mechanisms of action. They have many intracellular targets: they act as antimetabolites, competing with natural nucleosides during DNA or RNA synthesis, and as inhibitors of key cell enzymes. In contrast to other antineoplastic drugs, PNAs act cytotoxically, both in the mitotic and quiescent cell cycle phases. In the last few years, three PNAs have been approved for the treatment of lymphoid malignancies and other hematological disorders: 2-chlorodeoxyadenosine (2-CdA), fludarabine and pentostatin. 2-CdA and fludarabine are also active in the treatment of acute myeloid leukemia (AML). These drugs, in combination with cytarabine and other agents, are commonly used as salvage regimens in relapsed or refractory AML. Moreover, the addition of 2-CdA to the standard induction regimen is associated with an increased rate of complete remission and improved survival of adult patients with AML. More recently three novel PNAs have been synthesized and introduced into clinical trials: clofarabine, nelarabine and forodesine. Clofarabine is the most promising PNA in current clinical trials in pediatric and adult patients with acute leukemias. Nelarabine is more cytotoxic in T-lineage than in B-lineage leukemias. Clofarabine and nelarabine have been approved for the treatment of refractory patients with acute lymphoblastic leukemia (ALL) and lymphoblastic lymphoma. Clofarabine is also an active drug in AML treatment when administered either alone or in combination regimens as front-line treatment and in relapsed or refractory patients. Unlike other PNA, forodesine is not incorporated into DNA but displays a highly selective purine nucleoside phosphorylase inhibitory action. Forodesine is undergoing clinical trials for the treatment of T-cell malignancies, including T-cell ALL. This article summarizes recent achievements in the mechanism of action, pharmacological properties and clinical activity and toxicity of PNAs, as well as their emerging role in lymphoid and myeloid acute leukemias.

The mortality and response rate after FLANG regimen in patients with refractory/relapsed acute leukemia

Background:

Oncologists today are greatly concerned about the treatment of relapsed/refractory acute leukemia. FLANG regimen, combination of novantron, cytarabine, fludarabine, and granulocyte-colony stimulating factor, has been used in treatment of refractory/relapsed acute leukemia since 1990s. The present study has evaluated mortality and response rate of this regimen.

Materials and Methods:

In this study, 25 patients with refractory/relapsed acute leukemia aged 15-55 years underwent FLANG regimen at Seyed-Al-Shohada Hospital, Isfahan, Iran during 2008-2009. One month later, bone marrow samples were taken to evaluate the responsiveness to treatment. Participants were followed for a year. The data was analyzed by student-t and chi-square tests, logistic, and Cox regression analysis, and Kaplan-Meier curves in SPSS₁₉.

Results:

Out of the 25 patients, 8 patients (32%) had acute lymphoblastic leukemia (5 refractory and 3 relapsed cases) and 17 subjects had acute myeloid leukemia (7 refractory and 10 relapsed cases). According to the bone marrow biopsies taken one month after FLANG regimen, 10 patients (40%) had responded to treatment. Five patients of the 10 responders underwent successful bone marrow transplantation (BMT). On the other hand, 13 patients (52%), who had not entered the CR period, died during the follow-up. Logistic regression analysis did not reveal any significant associations between disease type and responsiveness to treatment.

Conclusion:

This study indicated higher rates of unresponsiveness to treatment while its mortality rate was comparable with other studies. Overall, according to limitations for BMT (as the only chance for cure) in Iran, it seems that FLANG therapy is an acceptable choice for these patients.

[Effectiveness and safety of the FLAG-IDA regimen in acute refractory or recurrent leukaemia]

OBJECTIVE

To evaluate the effectiveness and safety of the FLAG-IDA regimen in patients with acute refractory and/or recurrent leukaemia.

METHOD

Descriptive, retrospective, observational study of the clinical histories of patients with the FLAG-IDA regimen during the period of 2005-2010. Effectiveness was measured using objective response, progression-free interval, and global survival. Safety was measured using the NCI classification system of common toxicity criteria for adverse events.

RESULTS

We registered 12 patients (52.17±8.26 years in women, and 54.83±7.22 years in men), 11 cases were acute myeloid leukaemia (5 refractory, 3 in recurrence, 1 secondary to chronic refractory myeloid leukaemia (CML) and 2 secondary to myelodysplastic syndrome (MDS), one of which was refractory and the other had not been previously treated) and one case was acute refractory lymphoblastic leukaemia (ALL). Six patients (50%) reached a complete response (CR). One patient reached a partial response (PR), which was followed by another protocol that produced a CR, two died due to disease progression, and three due to secondary complications from treatment. The progression-free interval for patients that reached a CR was 24.38 weeks (6 months). Median global survival was 8.4 weeks. Mean time needed for the recovery of neutropenia was 23 and 37 days in the first and second cycle, respectively. The mean time required for recuperation of thrombocytopenia was 24 and 35 days in each cycle.

CONCLUSIONS

The FLAG-IDA induction regimen for the treatment of high-risk leukaemia patients is an established protocol, with good tolerance and acceptable toxicity levels that offers an opportunity for facilitating the transplantation of haematopoietic progenitors.

The prognostic impact of germline 46/1 haplotype of Janus kinase 2 in cytogenetically normal acute myeloid leukemia

BACKGROUND

Prognostic risk stratification according to acquired or inherited genetic alterations has received increasing attention in acute myeloid leukemia in recent years. A germline Janus kinase 2 haplotype designated as the 46/1 haplotype has been reported to be associated with an inherited predisposition to myeloproliferative neoplasms, and also to acute myeloid leukemia with normal karyotype. The aim of this study was to assess the prognostic impact of the 46/1 haplotype on disease characteristics and treatment outcome in acute myeloid leukemia.

DESIGN AND METHODS

Janus kinase 2 rs12343867 single nucleotide polymorphism tagging the 46/1 haplotype was genotyped by LightCycler technology applying melting curve analysis with the hybridization probe detection format in 176 patients with acute myeloid leukemia under 60 years diagnosed consecutively and treated with curative intent.

RESULTS

The morphological subtype of acute myeloid leukemia with maturation was less frequent among 46/1 carriers than among non-carriers (5.6% versus 17.2%, P = 0.018, cytogenetically normal subgroup: 4.3% versus 20.6%, P = 0.031), while the morphological distribution shifted towards the myelomonocytoid form in 46/1 haplotype carriers (28.1% versus 14.9%, P = 0.044, cytogenetically normal subgroup: 34.0% versus 11.8%, P = 0.035). In cytogenetically normal cases of acute myeloid leukemia, the 46/1 carriers had a considerably lower remission rate (78.7% versus 94.1%, P = 0.064) and more deaths in remission or in aplasia caused by infections (46.8% versus 23.5%, P = 0.038), resulting in the 46/1 carriers having shorter disease-free survival and overall survival compared to the 46/1 non-carriers. In multivariate analysis, the 46/1 haplotype was an independent adverse prognostic factor for disease-free survival (P = 0.024) and overall survival (P = 0.024) in patients with a normal karyotype. Janus kinase 2 46/1 haplotype had no impact on prognosis in the subgroup with abnormal karyotype.

CONCLUSIONS

Janus kinase 2 46/1 haplotype influences morphological distribution, increasing the predisposition towards an acute myelomonocytoid form. It may be a novel, independent unfavorable risk factor in acute myeloid leukemia with a normal karyotype.

Current and emerging therapies for acute myeloid leukemia

BACKGROUND

Acute myeloid leukemia (AML) is a clonal disease characterized by the proliferation and accumulation of myeloid progenitor cells in the bone marrow, which ultimately leads to hematopoietic failure. The incidence of AML increases with age, and older patients typically have worse treatment outcomes than do younger patients.

OBJECTIVE

This review is focused on current and emerging treatment strategies for nonpromyelocytic AML in patients aged <60 years.

METHODS

A literature review was conducted of the PubMed database for articles published in English. Publications from 1990 through March 2009 were scrutinized, and the search was updated on August 26, 2009. The search terms used were: acute myeloid leukemia in conjunction with treatment, chemotherapy, stem cell transplantation, and immunotherapy. Clinical trials including adults with AML aged > or =19 years were selected for analysis. Conference proceedings from the previous 5 years of The American Society of Hematology, The European Hematology Association, and The American Society for Blood and Marrow Transplantation were searched manually. Additional relevant publications were obtained by reviewing the references from the chosen articles.

RESULTS

Cytarabine (AraC) is the cornerstone of induction therapy and consolidation therapy for AML. A standard form of induction therapy consists of AraC (100-200 mg/m(2)), administered by a continuous infusion for 7 days, combined with an anthracycline, administered intravenously for 3 days. Consolidation therapy comprises treatment with additional courses of intensive chemotherapy after the patient has achieved a complete remission (CR), usually with higher doses of the same drugs as were used during the induction period. High-dose AraC (2-3 g/m(2)) is now a standard consolidation therapy for patients aged <60 years. Despite substantial progress in the treatment of newly diagnosed AML, 20% to 40% of patients do not achieve remission with the standard induction chemotherapy, and 50% to 70% of first CR patients are expected to relapse within 3 years. The optimum strategy at the time of relapse, or for patients with the resistant disease, remains uncertain. Allogeneic stem cell transplantation has been established as the most effective form of antileukemic therapy in patients with AML in first or subsequent remission. New drugs are being evaluated in clinical studies, including immunotoxins, monoclonal antibodies, nucleoside analogues, hypomethylating agents, farnesyltransferase inhibitors, alkylating agents, FMS-like tyrosine kinase 3 inhibitors, and multidrug-resistant modulators. However, determining the success of these treatment strategies ultimately requires well-designed clinical trials, based on stratification of the patient risk, knowledge of the individual disease, and the drug's performance status.

CONCLUSIONS

Combinations of AraC and anthracyclines are still the mainstay of induction therapy, and use of high-dose AraC is now a standard consolidation therapy in AML patients aged <60 years. Although several new agents have shown promise in treating AML, it is unlikely that these agents will be curative when administered as monotherapy; it is more likely that they will be used in combination with other new agents or with conventional therapy.

Continuous infusion of intermediate-dose cytarabine and fludarabine with idarubicin for patients younger than 60 years with resistant acute myeloid leukemia: a prospective, multicenter phase II study

We assessed continuous infusion (CI) of fludarabine and cytarabine (FLAG) plus idarubicin for patients under 60-years old with resistant acute myeloid leukemia (AML). Induction chemotherapy consisted of idarubicin (12 mg/m(2) iv infusion over 30 min on Days 1-3), plus fludarabine (30 mg/m2/day) and cytarabine (1,000 mg/m(2)/day) on Days 1-5 as a 24-hr CI. G-CSF was added on Days 1-5. The 29 patients enrolled were of median age 40 years (range, 18-57 years); of these, 8 (27.6%) had primary refractory disease, 19 (65.5%) were in early relapse, and 1 each (3.4%) was in multiple relapse and relapse after SCT. In response to induction, 8 patients (27.6%) achieved CR, 2 (6.9%) achieved CRp, and 19 (65.5%) failed treatment; of the latter, 14 had aplasia, three had an indeterminate course, and two showed resistance. Seven patients remain alive, while two were lost to follow-up. Nineteen patients died, 14 of infection, one of toxicity during consolidation, three of relapse after SCT, and two of persistent disease. These findings indicate that although CI of FLAG plus idarubicin was effective for eradicating blasts, it carried a high risk of toxicity. Reduced doses are recommended for CI of FLAG plus idarubicin.

Twice daily fludarabine/Ara-C associated to idarubicin, G-CSF and ATRA is an effective salvage regimen in non-promyelocytic acute myeloid leukemia

Preclinical data suggest that all-trans retinoic acid (ATRA) synergizing with granulocyte colony stimulating factor (G-CSF), can improve the effectiveness of chemotherapy in acute myeloid leukemia (AML). Fludarabine 15 mg/m(2) is the minimum dose able to optimize intensification with fludarabine-arabinosylcytosine regimen. In this study 52 patients with relapsed/refractory AML obtained a complete remission (CR) rate of 69.2% after FLAIRG regimen (Fludarabine and arabinosylcytosine twice daily, idarubicin, G-CSF, ATRA). This schedule resulted effective and tolerable enabling 53% of the responding patients to receive transplant procedure. FLAIRG regimen could be proposed as a "bridge" to transplant treatment in this poor risk setting.

Gemtuzumab ozogamicin as part of reduced-intensity conditioning for allogeneic hematopoietic cell transplantation in patients with relapsed acute myeloid leukemia

PURPOSE

Gemtuzumab ozogamicin (GO) has been associated with an increased risk of liver sinusoidal obstruction syndrome (SOS) when applied within 3 months of allogeneic hematopoietic cell transplantation (HCT). We hypothesized that GO might be safe and effective as part of a reduced-intensity conditioning regimen as salvage therapy of CD33+ acute myeloid leukemia.

EXPERIMENTAL DESIGN

Thirty-one patients with acute myeloid leukemia which relapsed following conventional therapy (n=15), autologous (n=3), or allogeneic (n=13) HCT were included in a prospective phase I/II trial. The preparative regimen contained 6 and 3 mg/m(2) of GO on days -21 and -14 before transplantation, leading to a reduction of marrow blasts in 18 patients (58%). Eight patients received further cytoreductive chemotherapy before conditioning therapy was initiated. Fludarabine-based reduced-intensity (n=11) or nonmyelablative (n=16) conditioning and peripheral blood stem cell infusion from related (n=6) or unrelated (n=21) donors could be done in 27 patients during cytopenia.

RESULTS

Primary engraftment occurred in all evaluable patients. Only one case of reversible hepatic sinusoidal obstruction syndrome was documented. Non-relapse mortality until day 100 was 22% (n=6). The probabilities of overall and disease-free survival at 24 months were 39% and 35%, respectively. Relapse of leukemia occurring between 2 and 24 months after transplantation (median, 8 months) was the major reason for treatment failure and death.

CONCLUSION

These data suggest that GO can be combined with reduced-intensity conditioning even after previous autologous or allogeneic HCT.

Phase I trial of FLAGM with high doses of cytosine arabinoside for relapsed, refractory acute myeloid leukemia: study of the Japan Adult Leukemia Study Group (JALSG)

This study was designed to determine the optimal high dose for cytosine arabinoside (ara-C) in combination with fludarabine, granulocyte colony-stimulating factor, and mitoxantrone (FLAGM) in adult patients with relapsed or refractory acute myeloid leukemia. Nine patients were enrolled at increasing dosage levels of ara-C (8, 12, and 16 g/m2 per dose level). Ara-C and fludarabine were administered once a day at level 1, once or twice a day at level 2, and twice a day at level 3. All patients had grade 4 hematologic toxicity. The most common adverse events were of grade 2 or less, with nausea and vomiting being the most common (6 events), followed by diarrhea (5 events), and rash (5 events). Of the 13 grade 3 nonhematologic toxicities reported, the 2 most common were febrile neutropenia (6 events) and disseminated intravascular coagulation (3 events). No early deaths were observed. FLAGM with high-dose ara-C was considered safe for patients, and the recommended dosage of ara-C in this study was 2 g/m2 every 12 hours for a total dose of 16 g/m2.

Cladribine combined with high doses of arabinoside cytosine, mitoxantrone, and G-CSF (CLAG-M) is a highly effective salvage regimen in patients with refractory and relapsed acute myeloid leukemia of the poor risk: a final report of the Polish Adult Leukemia Group

OBJECTIVES

Patients with primary refractory AML and with early relapses have unfavorable prognoses and require innovative therapeutic approaches. Purine analogs fludarabine (FA) and cladribine (2-CdA) increase cytotoxic effect of Ara-C in leukemic blasts and inhibit DNA repair mechanisms; therefore its association with Ara-C and mitoxantrone (MIT) results in a synergistic effect. In the current report, we present the final results of multi-center phase II study evaluating the efficacy and toxicity of CLAG-M salvage regimen in poor risk refractory/relapsed AML patients.

METHODS

The induction chemotherapy consisted of 2-CdA 5 mg/m2, Ara-C 2 g/m2, MIT 10 mg/m2, and granulocyte-colony stimulating factor. In the case of PR, a second CLAG-M was administered. Patients in CR received consolidation courses based on high doses of Ara-C and MIT with or without 2-CdA.

RESULTS

One hundred and eighteen patients from 11 centers were registered; 78 primary resistant and 40 relapsed. Sixty-six patients (58%) achieved CR after one or two courses of CLAG-M, 49 (35%) were refractory, and 8 (7%) died early. WBC >10 g/L and age >34 yr were factors associated with increased risk of treatment failure. Hematological toxicity was the most prominent toxicity of this regimen. The probability of OS at 4 yr was 14% (95% CI 4-23%). OS was influenced by age, WBC >10 g/L and poor karyotype in both univariate and multivariate analyses. The probability of 4 yr DFS was 30% for all 66 patients in CR (95% CI 11-49%). Poor karyotype was the only factor associated with decreased probability of DFS.

CONCLUSIONS

We conclude that CLAG-M is a well-tolerated and highly effective salvage regimen in poor risk refractory/relapsed AML.

Antiangiogenic activity of thalidomide in combination with fludarabine, carboplatin, and topotecan for high-risk acute myelogenous leukemia

Forty-two patients with poor prognosis AML were enrolled in a phase II study combining fludarabine, carboplatin, and topotecan (FCT) with thalidomide. Laboratory correlates included serum vascular endothelial growth factor levels (VEGF) and bone marrow microvascular density (MVD). Ten of 42 (24%) patients achieved a complete remission (CR or CRp). Serious thrombotic adverse events were observed in 5 patients suggesting that the combination of cytotoxic chemotherapy and thalidomide may be thrombogenic despite significant thrombocytopenia. VEGF did not correlate with response to therapy, while a trend towards decreased MVD was noted in patients who achieved CR. The addition of thalidomide did not significantly influence angiogenic markers. It is not clear that thalidomide adds any efficacy to the FCT regimen.

Fludarabine-mediated circumvention of cytarabine resistance is associated with fludarabine triphosphate accumulation in cytarabine-resistant leukemic cells

The combination of cytarabine (ara-C) with fludarabine is a common approach to treating resistant acute myeloid leukemia. Success depends on a fludarabine triphosphate (F-ara-ATP)-mediated increase in the active intracellular metabolite of ara-C, ara-C 5'-triphosphate (ara-CTP). Therapy-resistant leukemia may exhibit ara-C resistance, the mechanisms of which might induce cross-resistance to fludarabine with reduced F-ara-ATP formation. The present study evaluated the effect of combining ara-C and fludarabine on ara-C-resistant leukemic cells in vitro. Two variant cell lines (R1 and R2) were 8-fold and 10-fold more ara-C resistant, respectively, than the parental HL-60 cells. Reduced deoxycytidine kinase activity was demonstrated in R1 and R2 cells, and R2 cells also showed an increase in cytosolic 5'-nucleotidase II activity. Compared with HL-60 cells, R1 and R2 cells produced smaller amounts of ara-CTP. Both variants accumulated less F-ara-ATP than HL-60 cells and showed cross-resistance to fludarabine nucleoside (F-ara-A). R2 cells, however, accumulated much smaller amounts of F-ara-ATP and were more F-ara-A resistant than R1 cells. In HL-60 and R1 cells, F-ara-A pretreatment followed by ara-C incubation produced F-ara-ATP concentrations sufficient for augmenting ara-CTP production, thereby enhancing ara-C cytotoxicity. No potentiation was observed in R2 cells. Nucleotidase might preferentially degrade F-ara-A monophosphate over ara-C monophosphate, leading to reduced F-ara-ATP production and thereby compromising the F-ara-A-mediated potentiation of ara-C cytotoxicity in R2 cells. Thus, F-ara-A-mediated enhancement of ara-C cytotoxicity depended on F-ara-ATP accumulation in ara-C-resistant leukemic cells but ultimately was associated with the mechanism of ara-C resistance.

Role of fludarabine in hematological malignancies

Fludarabine is a prodrug that is converted to the free nucleoside 9-beta-D-arabinosyl-2-fluoroadenine (F-ara-A), which enters cells and accumulates mainly as the 5'-triphosphate, F-ara-ATP. F-ara-ATP has multiple mechanisms of action, which are mostly directed toward DNA. Collectively, these actions affect DNA synthesis, which is the major mechanism of F-ara-A-induced cytotoxicity. Secondarily, incorporation into RNA and inhibition of transcription has been shown in cell lines. As a single agent, fludarabine has been effective for indolent leukemia. Biochemical modulation strategies resulted in enhanced accumulation of cytarabine triphosphate and led to the use of fludarabine for the treatment of acute leukemia. The combination of fludarabine with DNA-damaging agents to inhibit DNA repair processes has been highly effective for indolent leukemia and lymphomas. Other strategies have incorporated fludarabine into preparative regimens for nonmyeloablative stem-cell transplantation.

IDA-FLAG regimen for the therapy of primary refractory and relapse acute leukemia: a single-center experience

We evaluated efficacy and toxicity profiles of fludarabine, Ara-C, idarubicin, and G-CSF (Ida-FLAG) combination chemotherapy in 56 refractory and/or relapsed acute leukemia patients. Patients were treated with fludarabine phosphate 25 mg/m2/d (d1-5), Ara-C 2 g/m2/d (d1-5), idarubicin 12 mg/m2/d (d1-3), G-CSF was given subcutaneously from sixth day until absolute neutrophil count (ANC) >500/microL. One third of the acute myeloblastic leukemia (AML) and 45% of acute lymphoblastic leukemia (ALL) cases were primary refractory disease. In AML patients, complete remission (CR) was achieved in 15 cases (53.6%). One case showed partial remission (PR) (3.6%) and 12 cases (42.8%) had resistant to this regimen (RD). Grade IV hematologic toxicity occurred in all AML cases. Leukocyte recovery time was 16 days. Nonhematologic complications were mild to moderate nausea, vomiting, and mucositis and could be controlled by routine measures. Stem cell transplantation was performed in 5 patients and all achieved CR, 2 autologous and 3 allogeneic. In ALL patients, CR and PR were obtained in 8 (42.2%) and 2 (10.5%) of 22 cases; disease was resistant to Ida-FLAG in 9 (47.3%) cases. Grade IV hematologic toxicity occurred in all ALL cases. Leukocyte recovery time was 17 days. Nonhematologic toxicity consisted of nausea, vomiting, and mucositis and could be controlled by supportive therapy. Autologous transplantation was performed in 1 patient, but relapse disease occurred after 5 weeks. There was no correlation between response rate and leukemia subtype (AML versus ALL), leukocyte count, age, sex, disease status (de novo versus secondary), and RFS (early versus late relapse) (P > 0.05). Median survival was 16 weeks in all cases (22 weeks in AML versus 13 weeks). At present, only 3 patients are alive and 2 of these are in continuous remission. The rest of the patients died. In conclusion, Ida-FLAG is a good choice in cases with refractory/relapsing acute leukemia for salvage chemotherapy. High efficacy and a low-toxicity profile are preferable properties of this regimen, and this regimen has been found to be useful for cytoreduction, especially in candidates for allo-SCT.

Fludarabine and cytosine are less effective than standard ADE chemotherapy in high-risk acute myeloid leukemia, and addition of G-CSF and ATRA are not beneficial: results of the MRC AML-HR randomized trial

The optimum chemotherapy schedule for reinduction of patients with high-risk acute myeloid leukemia (relapsed, resistant/refractory, or adverse genetic disease) is uncertain. The MRC AML (Medical Research Council Acute Myeloid Leukemia) Working Group designed a trial comparing fludarabine and high-dose cytosine (FLA) with standard chemotherapy comprising cytosine arabinoside, daunorubicin, and etoposide (ADE). Patients were also randomly assigned to receive filgrastim (G-CSF) from day 0 until neutrophil count was greater than 0.5 x 10(9)/L (or for a maximum of 28 days) and all-trans retinoic acid (ATRA) for 90 days. Between 1998 and 2003, 405 patients were entered: 250 were randomly assigned between FLA and ADE; 356 to G-CSF versus no G-CSF; 362 to ATRA versus no ATRA. The complete remission rate was 61% with 4-year disease-free survival of 29%. There were no significant differences in the CR rate, deaths in CR, relapse rate, or DFS between ADE and FLA, although survival at 4 years was worse with FLA (16% versus 27%, P = .05). Neither the addition of ATRA nor G-CSF demonstrated any differences in the CR rate, relapse rate, DFS, or overall survival between the groups. In conclusion these findings indicate that FLA may be inferior to standard chemotherapy in high-risk AML and that the outcome is not improved with the addition of either G-CSF or ATRA.

Treatment of acute myeloid leukemia during the second and third trimesters of pregnancy

Fortunately, the occurrence of acute myeloid leukemia (AML) during pregnancy is rare. We report a case of successful fetal outcome with standard induction and consolidation treatment in the second and third trimesters, respectively. A 37-year-old woman in her second trimester (21 wks) of pregnancy was found to have acute myeloid leukemia. She elected to maintain the pregnancy and underwent induction with cytarabine and idarubicin. Her hospital course was complicated by Pseudomonas vesicularis and gram-positive bacilli (not Bacillus anthracis) septicemia, but she obtained complete remission. After discharge, a fetal echocardiogram at 26 weeks revealed a mildly dilated right ventricle with mild systolic dysfunction, and the left ventricle appeared smaller than normal with mild systolic dysfunction. The patient then received consolidation therapy with high-dose cytarabine. On day 14 of consolidation, filgrastim 16 mug/kg was added to improve stem cell mobilization. A total of 19.8x10(6) CD34+ cells/kg were collected with a single apheresis session. At 37 weeks, she delivered a viable female infant weighing 3 lbs 12 oz. Fetal abnormalities included acrocyanosis, shallow sacral dimple, short digits and limbs, and prominent frontal skull with mild macrognathia. A postnatal echocardiogram revealed a moderate-sized membranous ventricular septal defect. The ventricular septal defect proved significant and required surgical repair at 5 months. Approximately 4 weeks after delivery, the mother underwent autologous peripheral stem cell transplantation. Unfortunately, 100 days after transplantation, she had a relapse of AML. After a brief remission from a second induction, the patient died.

Combination of tetrandrine as a potential-reversing agent with daunorubicin, etoposide and cytarabine for the treatment of refractory and relapsed acute myelogenous leukemia

The potential mechanism of the chemotherapy resistance in acute myeloid leukemia (AML) is the multidrug resistance (MDR-1) gene product P-glycoprotein (P-gp), which is often overexpressed in myeloblasts from acute myeloid leukemia. In a multicenter clinical trial, 38 patients with poor risk forms of AML were treated with tetrandrine (TET), a potent inhibitor of the MDR-1 efflux pump, combined with daunorubicin (DNR), etoposide and cytarabine (TET-DEC). Overall, post-chemotherapy marrow hypoplasia was achieved in 36 patients. Sixteen patients (42%) achieved complete remission or restored chronic phase, 9 achieved partial remission (PR) and 13 failed therapy. Toxicities included infection, myelosuppression, stomatitis, mucositis, cerebellar toxicity and reversible cardiotoxicity. There was no significant difference in response for P-gp-positive and -negative patients. P-gp function was assessed in 26 patients by flow cytometric analysis, TET-contained plasma-augmented DNR accumulation relative to pretreatment plasma in K562/A02 cells by a median value of 88+/-101% (range, 11-501%). However, there was no difference in DNR uptake between responding and non-responding patients. Our data showed that TET-DEC was relatively well tolerated in these patients with poor risk AML, and had encouraging antileukemic effects.

Treatment-related myelodysplastic syndrome/acute myeloid leukemia in survivors of childhood cancer--an update

Treatment-related myelodysplastic syndrome/acute myeloid leukemia (t-MDS/t-AML) is a devastating complication of treatment for childhood cancer. However, the major cause of premature death of children treated for cancer remains their primary cancer. The understanding of the presentation, incidence, predisposing risk factors and pathobiology of t-MDS/t-AML is increasing. This increased understanding has not yet been translated into improved outcomes of therapy for t-MDS/t-AML. However, newer approaches are under study.

A multicenter, open, noncomparative, phase II study of the combination of cladribine (2-chlorodeoxyadenosine), cytarabine, granulocyte colony-stimulating factor and mitoxantrone as induction therapy in refractory acute myeloid leukemia: a report of the Polish Adult Leukemia Group

Purine nucleoside analogues, cladribine (2-chlorodeoxyadenosine, 2-CdA) and fludarabine (FAMP) are active agents in acute myeloid leukemias (AMLs). Synergistic interaction between FAMP or 2-CdA with cytarabine (cytosine arabinoside, Ara-C) has been demonstrated in preclinical and clinical studies. The current multicenter phase II study was initiated to evaluate the efficacy and toxicity of induction treatment consisting of 2-CdA (5 mg/m2), Ara-C (2 g/m2), mitoxantrone (MIT, 10 mg/m2) and granulocyte colony-stimulating factor (G-CSF) (CLAG-M) in refractory AML. In case of partial remission, a second CLAG-M was administered. Patients in complete remission (CR) received consolidation courses based on high-dose Ara-C and MIT with or without 2-CdA. Forty-three patients from five centers were registered: 25 primary resistant and 18 relapsed. CR was achieved in 21 (49%) patients, 20 (47%) were refractory and 2 (5%) died early. Hematologic toxicity was the most prominent toxicity of this regimen. The overall survival (OS; 1 year) for the 42 patients as a whole and the 20 patients in CR were 43% and 73%, respectively. Disease-free survival (1 year) was 68.6%. None of the analyzed prognostic factors influenced the CR and OS probability significantly. We conclude that CLAG-M regimen has significant antileukemia activity in refractory AML, which seems to be better than the activity of many other regimens. The toxicity of the treatment is acceptable.

Prediction of individual response to chemotherapy in patients with acute myeloid leukaemia using the chemosensitivity index Ci

As the response to chemotherapy in patients with acute myeloid leukaemia (AML) may still not be accurately determined by known prognostic factors, such as karyotype, the ex vivo chemosensitivity profile may help to predict the individual response. The predictive accuracy of an ex vivo assay should be assessed by correlation of assay results with both response rate and survival. We prospectively investigated the prognostic relevance of pre-therapeutic ex vivo chemosensitivity testing in primary cell cultures from adult AML patients by applying a new evaluation methodology, designated the chemosensitivity index, C(i). This C(i) was designed as a prognostic index by taking the area under the curve as an exact measure of the total dose-response relationship. We found an overall predictive accuracy of 98.2% concerning treatment response, which compares favourably with previously published data ranging from 75% to 92%. Moreover, the C(i) proved to be the strongest prognostic factor for overall survival in a multivariate Cox regression analysis including karyotype grouping and age (P < 0.001), and enabled the evaluation of response to combination therapies and selection of possible treatment alternatives. Our data suggest that ex vivo chemosensitivity testing evaluated by the C(i) could serve as a powerful tool for assay-directed therapy strategies in AML.

Fludarabine, cytosine arabinoside, granulocyte-colony stimulating factor with or without idarubicin in the treatment of high risk acute leukaemia or myelodysplastic syndromes

The combination of fludarabine (FDR), high dose cytarabine and granulocyte colony stimulating factor (FLAG) with or without idarubicin (Ida) was used in the treatment of poor risk acute leukaemia or myelodysplastic syndrome (MDS) in a single centre experience. A total of 105 patients were treated over a 4-year period with 59% achieving a complete remission (CR); no statistical difference observed between FLAG and FLAG-Ida. For patients responding to FLAG +/- Ida, the median event-free survival (EFS) was 11 months and 23% at 5 years. Such patients proceeded either to further chemotherapy or a haematopoietic stem cell transplant (HSCT). The median EFS (13 months vs. 8 months) and projected 5-year survival (37% vs. 13%) of patients undergoing HSCT was significantly better than those who did not (P = 0.021). In all, 14 of 72 patients remain alive in continuing CR (median duration 43 months) with 10 of 31 having had a HSCT vs. four of 41 that did not (P = 0.033). Both regimens were well tolerated, with the majority of patients experiencing grade 1 or less non-haematological toxicity (mainly nausea and vomiting). The median time to neutrophil and platelet recovery was 28 and 31 d, respectively. No significant differences were seen with the addition of ida. There was a 17% incidence of treatment-related deaths, of which 39% was caused by invasive aspergillus infection. The results show that FLAG +/- Ida is an effective and well-tolerated remission induction regimen for poor risk leukaemia and MDS.

Sequential interleukin 3 and granulocyte-macrophage-colony stimulating factor therapy in patients with bone marrow failure with long-term follow-up of responses

BACKGROUND

Interleukin-3 (IL-3) and granulocyte-macrophage-colony stimulating factor (GM-CSF) have synergistic, hematopoietic growth-promoting activity in preclinical studies. Because of the paucity of effective therapies for patients with chronic bone marrow failure states, the authors studied the biologic activity of sequential IL-3/GM-CSF in such patients.

METHODS

IL-3 was given subcutaneously for 5 days (at escalating doses of 0.15 microg/kg, 0.3 microg/kg, 0.6 microg/kg, 1.2 microg/kg, 2.5 microg/kg, 5.0 microg/kg, 10.0 microg/kg, or 15.0 microg/kg per day), and GM-CSF for was given subcutaneously for 9 days (at a dose of 5 microg/kg per day; Phase I 3 + 3 design) followed by 14 days of rest (total, 2 courses), then maintenance therapy.

RESULTS

The majority of 38 evaluable patients had aplastic anemia or myelodysplastic syndrome. Most patients (79%) had neutrophil responses. Ten patients (26%), all of whom were treated with IL-3 doses >/= 1.2 microg/kg per day, had platelet responses, with a median increase of 132 x 10(9)/L (range, 41-180 x 10(9)/L) over baseline in responders. Six patients (16%) had trilineage recovery, which could be durable (the longest ongoing at 6.5 years after therapy completion). The most common toxicities were low-grade fever, headache, and fatigue. The maximum tolerated doses were IL-3 at 10 microg/kg per day and GM-CSF at 5 microg/kg per day.

CONCLUSIONS

Sequential IL-3/GM-CSF effectively raised blood counts in some patients with bone marrow failure at doses that were tolerated well. These results indicate that early-acting growth factors can induce durable, multilineage responses in a subset of individuals with bone marrow failure.

Biphenotypic acute leukemia following intensive adjuvant chemotherapy for breast cancer: case report and review of the literature

The risk of secondary leukemia in breast cancer patients who receive adjuvant chemotherapy is an open question. We describe the case a 38-year-old woman who developed acute leukemia 18 months after completion of intense adjuvant chemotherapy with prophylactic granulocyte colony-stimulating factor (G-CSF) support and chest wall irradiation. The diagnosis of biphenotypic T-cell acute myeloid leukemia (AML) was based on morphologic and immunophenotypic criteria. Chromosomal analysis of blasts revealed multiple trisomies and tetrasomies. The patient failed to respond to induction and salvage chemotherapy and died 4 months later. This case of acute leukemia occurred in a cohort of 65 high-risk breast cancer patients who were given intense adjuvant chemotherapy during the last 5 years in our hospital. This is the first case reported in the literature of acute leukemia following intense adjuvant chemotherapy with continuous prophylactic G-CSF, which is an actively investigated therapeutic strategy. Vigilance and investigation are needed to determine the leukemogenic potential of intense adjuvant chemotherapy plus radiotherapy in breast cancer patients. A brief review of the literature that deals with acute leukemia that develops after adjuvant chemotherapy for breast cancer and with secondary biphenotypic acute leukemia is presented.

Purine nucleoside analogues in the treatment of myleoid leukemias

The purine nucleoside analogues (PNA), fludarabine (FA), cladribine (2-chlorodeoxyadenosine, 2-CdA) and 2'-deoxycoformycin (DCF), represent a novel group of cytotoxic agents with high activity in low-grade lymphoid malignancies. However, several investigations have revealed that these agents are active also in acute myeloid leukemia (AML) and chronic myelogenous leukemia (CML). Synergistic interaction between FA or 2-CdA with cytarabine (Ara-C) have been demonstrated in both preclinical and clinical studies. PNA enhance the cell concentration of Ara-CTP, which is active metabolite of Ara-C. It is likely that the addition of granulocyte colony stimulating factor (G-CSF) may further improve the effects of FA (FLAG) or 2-CdA (CLAG). The addition of anthracyclines to induction therapy does not appear to result in a substantial advantage in terms of CR achievement and duration. An alternative approach to increase FLAG activity might be the addition of investigational drugs with novel mechanism of action, such as topoiromerase I inhibitors. The addition of anthracyclines to induction therapy does not appear to result in a substantial advantage in terms of CR achievement and duration. Clinical studies have confirmed the efficacy of PNA alone or in combination protocols in the treatment of AML. These regimens seem to produce superior results with acceptable toxicities in previously treated and relapsed, poor risk AML. However, early relapses remain a significant problem in a majority of refractory or relapsed patients in CR after treatment with PNA based regimens. To prolong remission duration or even cure AML, auto--or allo stem cell transplantation should be considered. However, FAMP or 2-CdA containing regimens may impair mobilization and collection of stem cells from peripheral blood for autotransplantation. Few studies have analyzed the role of PNA in CML. 2-CdA, FAMP and DCF can induce hematologic response in chronic phase of CML but cytogenetic responses have not been observed. Preliminary results suggest, that PNA used alone or in combination may be used as palliation in blast phase of the disease. However, currently, the role of these agents in CML is insignificant because of the high activity of Glivec in this disease. Finally, PNA, especially FA play an important role in non-myeloablative conditioning regimens for allogenic stem cell transplantation in high-risk patients, possibly also with myeloid malignancies.

The treatment of acute myeloid leukemia in first relapse: a comprehensive review of the literature

Twenty years of published literature was reviewed for chemotherapy regimens used to treat patients with acute myeloid leukemia (AML) in first relapse. Thirty-one trials containing at least 20 patients in first relapse and information on patient age, duration of first complete remission (CR1), and rate of second complete remission (CR2) were analyzed. These trials included 10 retrospective studies with CR2 rates ranging from 30 to 64%, two phase II single-agent studies with CR2 rates of 8 and 25%, 15 phase II combination-agent studies with CR2 rates ranging from 14 to 87%, and four phase III randomized studies with CR2 rates ranging from 40 to 89%. When reported, median duration of CR2 was < or = 14 months and overall median survival was < or = 12 months. The probability of 3-year survival ranged from 8 to 29%. Combination therapies resulted in higher CR2 rates but were associated with longer duration of myelosuppression and greater incidence of mucositis. None of the reviewed regimens provided durable remissions for the majority of AML patients in first relapse. The CR2 rates were closely associated with age and duration of CR1. Therefore, considering the poor clinical outcomes of patients with AML in first relapse, improved therapies need to be developed.

P-glycoprotein in acute myeloid leukaemia: therapeutic implications of its association with both a multidrug-resistant and an apoptosis-resistant phenotype

P-glycoprotein (Pgp) expression is an independent prognostic factor for response to remission-induction chemotherapy in acute myeloblastic leukaemia, particularly in the elderly. There are several potential agents for modulating Pgp-mediated multi-drug resistance, such as cyclosporin A and PSC833, which are currently being evaluated in clinical trials. An alternative therapeutic strategy is to increase the use of drugs which are unaffected by Pgp. However, in this review, we explain why this may be more difficult than it appears. Evidence from in vitro studies of primary AML blasts supports the commonly held supposition that chemoresistance may be linked to apoptosis-resistance. We have found that Pgp has a drug-independent role in the inhibition of in vitro apoptosis in AML blasts. Modulation of cytokine efflux, signalling lipids and intracellular pH have all been suggested as ways by which Pgp may affect cellular resistance to apoptosis; these are discussed in this review. For a chemosensitising agent to be successful, it may be more important for it to enhance apoptosis than to increase drug uptake.

Flexible low-intensity combination chemotherapy for elderly patients with acute myeloid leukemia

Twenty-five patients aged 57 to 88 years (median, 70 years) with acute myeloid leukemia were treated with a flexible low-intensity treatment regimen comprising mitozantrone (mitoxantrone) 6 mg/m2 administered by intravenous infusion x3 days, cytarabine 10 mg/m2 subcutaneously every 12 hours x7 to 14 days, and etoposide 100 mg orally x7 to 14 days. Seventeen of these patients had a preexisting myelodysplastic syndrome. The clinical response was correlated to the results of cytogenetic studies (23 patients) and of viability studies of leukemic blasts (7 patients). Eleven of the 25 patients achieved complete remission (CR), 8 achieved partial remission (PR), and 4 showed no response. There was 1 toxic death, and 1 patient died soon (1 week) after presentation. Treatment was well tolerated. Although myelotoxicity occurred regularly, the recovery time was < or = 3 weeks for most of the responding patients. Duration of survival for patients who had CR has ranged from 4+ to 43+ months and for patients who had PR, 3 to 16 months. Irrespective of the remission status (CR or PR), responding patients with favorable (n = 1) or intermediate (n = 10) cytogenetic findings had a significantly better survival time (median, 14 months) than did those with unfavorable (n = 7) cytogenetic findings (median, 5 months). In vitro studies showed a progressive reduction in the number of circulating blasts. The number of viable blasts 3 days after initiation of therapy appeared to give an early indication of clinical response. Treatment with a flexible low-intensity protocol seems to achieve results comparable with those reported for intensive antileukemia therapy and has much less toxicity.

Minimal residual disease tests provide an independent predictor of clinical outcome in adult acute lymphoblastic leukemia

PURPOSE

Investigation of minimal residual disease (MRD) in childhood acute lymphoblastic leukemia (ALL) using molecular markers has proven superior to other standard criteria (age, sex, and WBC) in distinguishing patients at high, intermediate, and low risk of relapse. The aim of our study was to determine whether MRD investigation is valuable in predicting outcome in Philadelphia-negative adult patients with ALL.

PATIENTS AND METHODS

MRD was assessed in 85 adult patients with B-lineage ALL by semiquantitative immunoglobulin H gene analysis on bone marrow samples collected during four time bands in the first 24 months of treatment. Fifty patients received chemotherapy only and 35 patients received allogeneic (n = 19) or autologous (n = 16) bone marrow transplantation (BMT) in first clinical remission. The relationship between MRD status and clinical outcome was investigated and compared with age, sex, immunophenotype, and presenting WBC count.

RESULTS

Fisher's exact test established a statistically significant concordance between MRD results and clinical outcome at all times. Disease-free survival (DFS) rates for MRD-positive and -negative patients and log-rank testing established that MRD positivity was associated with increased relapse rates at all times (P <.05) but was most significant at 3 to 5 months after induction and beyond. MRD status after allogeneic BMT rather than before was found to be an important predictor of outcome in 19 adult patients with ALL tested. In patients receiving autologous BMT (n = 16), the MRD status before BMT was more significant (P =.005).

CONCLUSION

The association of MRD test results and DFS was independent of and greater than other standard predictors of outcome and is therefore important in determining treatment for individual patients.

Trends in bacteraemia on the haematology and oncology units of a UK tertiary referral hospital

As part of ongoing surveillance of infection in the haematology and oncology units at Belfast City Hospital, microbiologically documented bloodstream infections over three 12-month periods 1994/5, 1998/9 and 1999/00 were reviewed. Gram-positive organisms were the most common cause of blood stream infection in the haematology unit causing 66%, 56% and 64% of episodes of monomicrobial bacteraemia in 1994/5, 1998/9 and 1999/00, respectively. In haematology patients, enterococci have emerged as an important cause of bacteraemia, with increasing levels of glycopeptide resistance, and the 'non-fermenting Gram-negative rods other than Pseudomonas aeruginosa' are an increasingly common cause of monomicrobial and polymicrobial bacteraemia. In oncology patients, Gram-negative organisms (predominantly enterobacteriaceae) were more common than Gram-positive organisms, causing 50% and 54% of monomicrobial bacteraemia in 1998/9 and 1999/00, respectively. Changes in patient population, underlying diseases and chemotherapeutic agents may explain these findings. The spectrum of infection seen in haematology and oncology patients changes as management evolves. Ongoing co-operation between haematologists, oncologists and microbiologists is important to detect trends in epidemiology, which can be used to design empirical antibiotic regimens and guide infection control policies.

The role of purine analogue combinations in the management of acute leukemias

Cytosine arabinoside plays a pivotal role in the therapy of acute myeloid leukemias with the concentration of its active metabolite, ara-CTP, being positively correlated with improved clinical outcome. Both in vitro studies and ex vivo studies have confirmed the ability of the purine analogues to enhance ara-CTP accumulation within leukemic cells via the stimulation of deoxycytidine kinase. Clinical studies have confirmed the efficacy of these combination regimes in the treatment of acute leukemias. The basis of the biochemical rationale for the development of combination chemotherapy regimes with purine analogues for acute leukemias is reviewed along with clinical studies of their effectiveness and toxicity.

Idarubicin, cytarabine, and topotecan in patients with refractory or relapsed acute myelogenous leukemia and high-risk myelodysplastic syndrome

In an effort to develop more effective therapy for patients with refractory or relapsed acute myelogenous leukemia (AML) and high-risk myelodysplastic syndrome (MDS), we investigated the efficacy of a combination chemotherapy consisting of idarubicin, cytarabine, and topotecan. Twenty-seven patients were treated: four with primary refractory AML, nine with AML in first relapse, four with AML in second relapse, and 10 with MDS-RAEB/RAEBT. Patients received as salvage therapy a single course of idarubicin 12 mg/m(2) IV bolus on days 1-3, cytarabine 1 g/m(2) over two hours q 12 hr on days 1-5, and topotecan 1.25 mg/m(2) over 24 hr on days 1-5. Median age was 42 years (range 17-65 years). All patients were evaluable for response: 14 (51.9%) achieved complete remission, 10 with AML (59%) and four with MDS (40%), respectively. Thirteen AML patients (excluding four relapsed after autologous stem cell transplantation) were grouped into four categories to stratify the probability of achieving complete remission (CR): group 1, first CR duration > or = 2 years and receiving first salvage treatment (S1); group 2, first CR duration 1-2 years and receiving S1; group 3, first CR duration 0-1 years and receiving S1; and group 4, first CR duration 0-1 years and receiving S2, S3, or S4 after failing S1. The response rate of each group was as follows: group 1, one of two (50%); group 2, one of one (100%); group 3, four of four (100%); group 4, two of six (33.3%). The median remission duration and survival of patients with AML were six and 12 months, respectively. Median duration of survival in 10 MDS patients was 15 months, and all four MDS patients achieving a CR maintained continuous CR with a median follow-up of 11 months. Severe myelosuppression was observed in all patients, resulting in fever or documented infections in 89% of patients. Median time to recovery of neutrophils > or =0.5 x 10(9)/l was 22 days (11-34) and for platelets > 20 x 10(9)/l 35 days (11-58). Reversible grade 3-4 toxicities included diarrhea (two patients) and mucositis (seven patients). We conclude that combination chemotherapy with intermediate dose cytarabine, idarubicin, and topotecan has significant antileukemic activity and acceptable toxicity in salvage AML and high-risk MDS.

Inhibitory effects of IFN-gamma and acyclovir on the glioblastoma cell cycle

Glioblastoma multiforme is one of the most aggressive and frequently occurring forms of brain cancer. It originates from astrocytes and is characterized by a loss of cell cycle control frequently involving mutations in tumor suppressor genes, such as p53 and p16. Nucleoside analogs, such as acyclovir (ACV), are currently being used in the treatment of viral diseases, such as those caused by members of the herpes family. Further, ACV in combination with type I interferons (IFN) has been shown to be more effective at lower doses in treatment of viral diseases. We show here that ACV at high concentrations (up to 500 microg/ml) inhibited growth in tissue culture of the human glioblastoma cell lines T98G, SNB-19, and U-373 by as much as 68.3% while inhibiting normal human astrocytes by only 38.3%. Related to this, the tumor cells were more than sevenfold more efficient in phosphorylation of ACV to the active phosphate form than normal human astrocytes. Analogous to treatment of virus-infected cells, suboptimal concentrations of ACV were as effective as high concentrations when used in conjunction with low concentrations of IFN-gamma in inhibition of tumor cell growth. At the cellular level, ACV and IFN-gamma inhibited the cell cycle in both the G1 and S phases. The cooperative effect of ACV and IFN-gamma against the glioblastomas appears to be due to direct inhibition of DNA synthesis by ACV in the S phase of the cell cycle and induction by IFN-gamma of the tumor suppressor gene p21wAF1/CIP1, which in turn acts at the level of proliferating cell nuclear antigen (PCNA) and cyclin E/cyclin-dependent kinase 2 (Cdk2) binding and inhibition of function. These studies show that the combination of IFN-gamma and ACV at suboptimal concentrations elicits significant antiproliferative effects on the glioblastoma cell lines T98G, SNB-19, and U-373 while having very little effect on normal human astrocyte cell proliferation.