Myeloid growth factors in acute myeloid leukemia: systematic review of randomized controlled trials

The Impact of Prophylactic Post-Chemotherapy G-CSF on the Relapse Rates in Patients with Acute Myeloid Leukemia: A Meta-Analysis

This meta-analysis evaluated the impact of prophylactic post-chemotherapy granulocyte colony-stimulating factor (G-CSF) in patients with acute myeloid leukemia (AML). Overall, the relapse rate, overall survival, event-free survival, and mortality rate were similar in G-CSF (+) compared to G-CSF (-) patients. However, the relative risk (RR) of relapse was higher in children and in secondary AML patients who were treated with G-CSF compared to the G-CSF (-) group [RR, 95% confidence interval: 1.26, 1.04-1.52, and 1.12 (1.02-1.24)]. Treatment with post-chemotherapy G-CSF should be prescribed with caution in pediatric patients with AML and secondary AML as possibly increasing the relapse risk.

Consolidation in AML: Abundant opinion and much unknown

Consolidation therapy forms the backbone of post-remission therapy for AML and is uniformly accepted as an integral part of therapy designed to achieve long-term survival. The need for post-remission therapy was initially described over four decades ago and has since undergone many variations in terms of dosage, number of cycles and intensity of therapy. There is much empiricism in the current understanding of consolidation therapy and much that has not been rigorously studied. This review will consider the many aspects of consolidation therapy, focusing on the number of cycles, differences between young and older adults, first and subsequent remission as well as therapy prior to an allogeneic transplant. Emphasis will be given to differentiate strategies that are clearly evidence-based from those that have been incorporated into standard of care while bypassing the need for rigorous data-driven approaches. Finally, consideration will be given to the current ability to assess the minimal measureable residual disease and the impact that this may have on therapeutic paradigms, including superseding many of the time-honored prognostic features.

Management of fever and neutropenia in the adult patient with acute myeloid leukemia

INTRODUCTION

Febrile neutropenia represents one of the most common treatment-associated complications in the management of acute myeloid leukemia (AML) and is considered an oncologic emergency. Rapid and detailed workup as well as the initiation of empiric broad-spectrum antibiotic therapy are critical to avoid sepsis and to reduce mortality. Although a definitive source of infection is frequently not identified, the severely immunosuppressed status of the AML patient undergoing cytotoxic therapy results in a high risk for a wide array of bacterial, fungal, and viral etiologies.

AREAS COVERED

The authors herein review the diagnostic and therapeutic approach to the neutropenic leukemia patient based on the current knowledge. Special consideration is given to the rapidly changing therapeutic landscape in AML, creating new challenges in the management of infectious complications.

EXPERT OPINION

Multidrug-resistant organisms pose a major challenge in the management of neutropenic fever patients with hematologic malignancies - including AML. Future directions to improve outcomes demand innovative treatment approaches as well as advances in biomarker research to facilitate diagnosis and disease monitoring. Recent achievements in AML-targeted therapy led to an increased incidence of differentiation syndrome, a potentially life-threatening side effect that frequently resembles clinical infection and requires prompt recognition and aggressive intervention.

Pharmacological prophylaxis of infection in pediatric acute myeloid leukemia patients

Introduction: Pediatric patients treated for acute myeloid leukemia (AML) are at high risk of developing severe infectious complications. The choice of an optimum supportive treatment should be based on local epidemiology, as well as intensity and toxicity of the anti-leukemic therapy applied.Areas covered: This review presents an overview of recently published studies focusing on the prevention of infection in pediatric AML patients. PubMed has been systematically searched for clinical trials, reviews, and meta-analyses published in the last 10 years. The focus of this article will be limited to primary prophylaxis only, while secondary prophylaxis is beyond the scope of the current review.Expert opinion: Although anti-bacterial agents may decrease the bacterial infection burden, there is no consensus regarding prophylactic use. To that end, there is a need for further randomized controlled trials to establish the precise role of anti-bacterial prophylaxis in pediatric AML patients. The prophylactic use of anti-fungal agents is strongly recommended for all AML patients. Since the contribution of hematopoietic growth factors to improved survival has not been demonstrated, they should not be routinely applied. Decisions regarding an appropriate prophylactic strategy should be taken in collaboration with the infectious disease experts and pharmacology team.

Chemotherapy and Beyond: Infections in the Era of Old and New Treatments for Hematologic Malignancies

Treatment options for hematologic malignancies have been rapidly expanding in the past decade, resulting in better survival outcomes for many patients. Infection is an important cause of morbidity and mortality in this patient population. Cytotoxic chemotherapy has well-studied infectious risks related to the degree and duration of myelosuppression. Targeted therapies and immunotherapies have less clearly predictable infectious risk and diverse effects on immune function. This review discusses contemporary management of hematologic malignancies, followed by special discussion of novel agents, including signaling/small molecule inhibitors, monoclonal antibodies, immunomodulators, and immunotherapies, for treatment of hematologic malignancies with focus on infectious risk.

Effect of Granulocyte Colony-Stimulating Factor-Combined Conditioning in Cord Blood Transplantation for Myelodysplastic Syndrome and Secondary Acute Myeloid Leukemia: A Retrospective Study in Japan

Granulocyte colony-stimulating factor (G-CSF) increases the susceptibility of dormant malignant or nonmalignant hematopoietic cells to cytarabine arabinoside (Ara-C) through the induction of cell cycle entry. Therefore, G-CSF-combined conditioning before allogeneic stem cell transplantation might positively contribute to decreased incidences of relapse and graft failure without having to increase the dose of cytotoxic drugs. We conducted a retrospective nationwide study of 336 adult patients with myelodysplastic syndrome (MDS) and secondary acute myeloid leukemia (sAML) after single-unit cord blood transplantation (CBT) who underwent 4 different kinds of conditioning regimens: total body irradiation (TBI) ≥ 8 Gy + Ara-C/G-CSF + cyclophosphamide (CY) (n = 65), TBI ≥ 8 Gy + Ara-C + CY (n = 119), TBI ≥ 8 Gy + other (n = 104), or TBI < 8 Gy or non-TBI (n = 48). The TBI ≥ 8 Gy + Ara-C/G-CSF + CY regimen showed significantly higher incidence of neutrophil engraftment (hazard ratio, 1.52; 95% confidence interval [CI], 1.10 to 2.08; P = .009) and lower overall mortality (hazard ratio, .46; 95% CI, .26 to .82; P = .008) rates compared with those without a G-CSF regimen. This retrospective study shows that the G-CSF-combined conditioning regimen provides better engraftment and survival results in CBT for adults with MDS and sAML.

Anti-infective prophylaxis in pediatric patients with acute myeloid leukemia

Pediatric patients undergoing treatment for acute myeloid leukemia (AML) are at high risk for infectious complications, predominantly due to Gram-negative bacteria, viridans group streptococci and fungal pathogens. In order to prevent infections in these patients, most institutions have implemented a number of non-pharmacological approaches to supportive care. In addition, antibiotic prophylaxis reduces bacterial infection, but may increase the emergence of resistance. Antifungal prophylaxis is generally recommended for children with AML. Whereas the use of hematopoietic growth factors has not resulted in improved survival, the efficacy of prophylactic granulocyte transfusions has to be determined.

Concise review: next-generation cell therapies to prevent infections in neutropenic patients

High-dose chemotherapy is accompanied by an obligate period of neutropenia. Resulting bacterial and fungal infections are the leading cause of morbidity and mortality in neutropenic patients despite prophylactic antimicrobials and hematopoietic growth factor supplements. Replacing neutrophils in the patient through transfusion of donor cells is a logical solution to prevent fulminant infections. In the past, this strategy has been hampered by poor yield, inability to store collected cells, and possible donor morbidity caused by granulocyte colony-stimulating factor injections and apheresis. Today, neutrophil-like cells can be manufactured in the laboratory at the clinical scale from hematopoietic stem and progenitor cells enriched from umbilical cord blood. This article reviews the rationale for focusing research efforts toward ex vivo neutrophil production and explores clinical settings for future trials.

Long-term results of a prospective randomized trial evaluating G-CSF priming in intensive induction chemotherapy followed by autologous stem cell transplantation in elderly patients with acute myeloid leukemia

Few studies have evaluated granulocyte colony-stimulating factor (G-CSF) priming in elderly patients with intensively treated acute myeloid leukemia (AML), and no data are available for genetically defined AML subgroups. We provide long-term results (median follow-up 7.6 years) of a randomized trial in which 183 patients (median age 67 years) received G-CSF prior to (G-CSF priming) or after two cycles of induction chemotherapy. CR rates with G-CSF priming and G-CSF post-chemotherapy were comparable (57 vs. 67 %, p = 0.153), with overall survival (OS) probabilities of 14 vs. 17 % at 10 years. Induction mortality was significantly higher with G-CSF priming (23 vs. 10 %, p = 0.015), primarily in normal karyotype (NK) AML. In this subgroup, a trend for better relapse-free survival (RFS) was observed with G-CSF priming (44 vs. 22 % at 10 years, p = 0.074) but did not translate into an OS benefit. G-CSF priming had no impact on AML with FLT3-ITD and NPM mutations and did not improve outcome in patients with adverse cytogenetics. In a landmark analysis, late consolidation with autologous stem cell transplantation or a second consolidation cycle significantly improved RFS compared with one consolidation cycle (21.0 vs. 12.8 months, p = 0.046). Future studies on G-CSF priming should be restricted to NK AML and used only in post-remission therapy.

Colony-stimulating factors for prevention and treatment of infectious complications in patients with acute myelogenous leukemia

BACKGROUND

Acute myelogenous leukemia (AML) is a fatal bone marrow cancer. Colony-stimulating factors (CSFs) are frequently administered during and after chemotherapy to reduce complications. However, their safety with regard to disease-related outcomes and survival in AML is unclear. Therefore, we performed a systematic review and meta-analysis to evaluate the impact of CSFs on patient outcomes, including survival.

OBJECTIVES

To assess the safety/efficacy of CSFs with regard to disease-related outcomes and survival in patients with AML.

SEARCH METHODS

We conducted a comprehensive search strategy. We identified relevant randomized clinical trials by searching the Cochrane Central Register of Controlled Trials (The Cochrane Library 2010, Issue 7), MEDLINE (January 1966 to July 2010), LILACS (up to December 2009), databases of ongoing trials and relevant conference proceedings.

SELECTION CRITERIA

Randomized controlled trials that compared the addition of CSFs during and following chemotherapy to chemotherapy alone in patients with AML. We excluded trials evaluating the role of CSFs administered for the purpose of stem cell collection and/or priming (e.g. before and/or only for the duration of chemotherapy).

DATA COLLECTION AND ANALYSIS

Two review authors appraised the quality of trials and extracted data. For each trial, we expressed results as relative risk (RR) with 95% confidence intervals (CI) for dichotomous data. We analyzed time-to-event outcomes as hazard ratios (HRs).

MAIN RESULTS

The search yielded 19 trials including 5256 patients. The addition of CSFs to chemotherapy yielded no difference in all-cause mortality at 30 days and at the end of follow up (RR 0.97; 95% CI 0.80 to 1.18 and RR 1.01; 95% CI 0.98 to 1.05, respectively) or in overall survival (HR 1.00; 95% 0.93 to 1.08). There was no difference in complete remission rates (RR 1.03; 95% CI 0.99 to 1.07), relapse rates (RR 0.97; 95% CI 0.89 to 1.05) and disease-free survival (HR 1.00; 95% CI 0.90 to 1.13). CSFs did not decrease the occurrence of bacteremias (RR 0.96; 95% CI 0.82 to 1.12), nor the occurrence of invasive fungal infections (RR 1.40; 95% CI 0.90 to 2.19). CSFs marginally increased adverse events requiring discontinuation of CSFs as compared to the control arm (RR 1.33; 95% CI 1.00 to 1.56).

AUTHORS' CONCLUSIONS

In summary, colony-stimulating factors should not be given routinely to acute myelogenous leukemia patients post-chemotherapy since they do not affect overall survival or infectious parameters including the rate of bacteremias and invasive fungal infections.

Colony-stimulating factors in the prevention and management of infectious diseases

Colony-stimulating factors (CSFs) are attractive adjunctive anti-infective therapies. Used to enhance innate host defenses against microbial pathogens, the myeloid CSFs increase absolute numbers of circulating innate immune effector cells by accelerating bone marrow production and maturation, or augment the function of those cells through diverse effects on chemotaxis, phagocytosis, and microbicidal functions. This article summarizes the evidence supporting the accepted clinical uses of the myeloid CSFs in patients with congenital or chemotherapy-induced neutropenia, and presents an overview of proposed and emerging uses of the CSFs for the prevention and treatment of infectious diseases in other immunosuppressed and immunocompetent patient populations.

Colony-stimulating factors for prevention and treatment of infectious complications in patients with acute myelogenous leukemia

BACKGROUND

Acute myelogenous leukemia (AML) is a fatal bone marrow cancer. Colony-stimulating factors (CSFs) are frequently administered during and after chemotherapy to reduce complications. However, their safety with regard to disease-related outcomes and survival in AML is unclear. Therefore, we performed a systematic review and meta-analysis to evaluate the impact of CSFs on patient outcomes, including survival.

OBJECTIVES

To assess the safety/efficacy of CSFs with regard to disease-related outcomes and survival in patients with AML.

SEARCH STRATEGY

We conducted a comprehensive search strategy. We identified relevant randomized clinical trials by searching the Cochrane Central Register of Controlled Trials (The Cochrane Library 2010, Issue 7), MEDLINE (January 1966 to July 2010), LILACS (up to December 2009), databases of ongoing trials and relevant conference proceedings.

SELECTION CRITERIA

Randomized controlled trials that compared the addition of CSFs during and following chemotherapy to chemotherapy alone in patients with AML. We excluded trials evaluating the role of CSFs administered for the purpose of stem cell collection and/or priming (e.g. before and/or only for the duration of chemotherapy).

DATA COLLECTION AND ANALYSIS

Two review authors appraised the quality of trials and extracted data. For each trial, we expressed results as relative risk (RR) with 95% confidence intervals (CI) for dichotomous data. We analyzed time-to-event outcomes as hazard ratios (HRs).

MAIN RESULTS

The search yielded 19 trials including 5256 patients. The addition of CSFs to chemotherapy yielded no difference in all-cause mortality at 30 days and at the end of follow up (RR 0.97; 95% CI 0.80 to 1.18 and RR 1.01; 95% CI 0.98 to 1.05, respectively) or in overall survival(HR 1.00; 95% 0.93 to 1.08). There was no difference in complete remission rates(RR 1.03; 95% CI 0.99 to 1.07), relapse rates(RR 0.97; 95% CI 0.89 to 1.05) and disease-free survival(HR 1.00; 95% CI 0.90 to 1.13). CSFs did not decrease the occurrence of bacteremias(RR 0.96; 95% CI 0.82 to 1.12), nor the occurrence of invasive fungal infections(RR 1.40; 95% CI 0.90 to 2.19). CSFs marginally increased adverse events requiring discontinuation of CSFs as compared to the control arm(RR 1.33; 95% CI 1.00 to 1.56).

AUTHORS' CONCLUSIONS

The addition of CSFs to chemotherapy does not adversely influence all-cause mortality, complete remission or relapse rates in patients with AML. Although the benefit of CSFs is limited to reduction of neutropenic and febrile days, they can be administered safely when necessary.