A multicentre, open, non-comparative phase II study of a combination of fludarabine phosphate, cytarabine and granulocyte colony-stimulating factor in relapsed and refractory acute myeloid leukaemia and de novo refractory anaemia with excess of blasts in transformation

Guadecitabine vs TC in relapsed/refractory AML after intensive chemotherapy: a randomized phase 3 ASTRAL-2 trial

ABSTRACT

Guadecitabine is a novel hypomethylating agent (HMA) resistant to deamination by cytidine deaminase. Patients with relapsed/refractory acute myeloid leukemia (AML) were randomly assigned to guadecitabine or a preselected treatment choice (TC) of high-intensity chemotherapy, low-intensity treatment with HMAs or low-dose cytarabine, or best supportive care (BSC). The primary end point was overall survival (OS). A total of 302 patients were randomly assigned to guadecitabine (n = 148) or TC (n = 154). Preselected TCs were low-intensity treatment (n = 233 [77%; mainly HMAs]), high-intensity chemotherapy (n = 63 [21%]), and BSC (n = 6 [2%]). The median OS were 6.4 and 5.4 months for guadecitabine and TC, respectively (hazard ratio 0.88 [95% confidence interval, 0.67-1.14]; log-rank P = .33). Survival benefit for guadecitabine was suggested in several prospective subgroups, including age <65 years, Eastern Cooperative Oncology Group performance status 0 to 1, refractory AML, and lower peripheral blood blasts ≤30%. Complete response (CR) + CR with partial hematologic recovery rates were 17% for guadecitabine vs 8% for TC (P < .01); CR+CR with incomplete count recovery rates were 27% for guadecitabine vs 14% for TC (P < .01). Safety was comparable for the 2 arms, but guadecitabine had a higher rate of grade ≥3 neutropenia (32% vs 17%; P < .01). This study did not demonstrate an OS benefit for guadecitabine. Clinical response rates were higher for guadecitabine, with comparable safety to TC. There was an OS benefit for guadecitabine in several prespecified subgroups. This study was registered at www.clinicaltrials.gov as #NCT02920008.

Theranostic Potentials of Gold Nanomaterials in Hematological Malignancies

Simple Summary

Hematological malignancies (HMs) cover 50% of all malignancies, and people of all ages can be affected by these deadly diseases. In many cases, conventional diagnostic tools fail to diagnose HMs at an early stage, due to heterogeneity and the long-term indolent phase of HMs. Therefore, many patients start their treatment at the late stage of HMs and have poor survival. Gold nanomaterials (GNMs) have shown promise as a cancer theranostic agent. GNMs are 1 nm to 100 nm materials having magnetic resonance and surface-plasmon-resonance properties. GNMs conjugated with antibodies, nucleic acids, peptides, photosensitizers, chemotherapeutic drugs, synthetic-drug candidates, bioactive compounds, and other theranostic biomolecules may enhance the efficacy and efficiency of both traditional and advanced theranostic approaches to combat HMs.

Abstract

Hematological malignancies (HMs) are a heterogeneous group of blood neoplasia generally characterized by abnormal blood-cell production. Detection of HMs-specific molecular biomarkers (e.g., surface antigens, nucleic acid, and proteomic biomarkers) is crucial in determining clinical states and monitoring disease progression. Early diagnosis of HMs, followed by an effective treatment, can remarkably extend overall survival of patients. However, traditional and advanced HMs’ diagnostic strategies still lack selectivity and sensitivity. More importantly, commercially available chemotherapeutic drugs are losing their efficacy due to adverse effects, and many patients develop resistance against these drugs. To overcome these limitations, the development of novel potent and reliable theranostic agents is urgently needed to diagnose and combat HMs at an early stage. Recently, gold nanomaterials (GNMs) have shown promise in the diagnosis and treatment of HMs. Magnetic resonance and the surface-plasmon-resonance properties of GNMs have made them a suitable candidate in the diagnosis of HMs via magnetic-resonance imaging and colorimetric or electrochemical sensing of cancer-specific biomarkers. Furthermore, GNMs-based photodynamic therapy, photothermal therapy, radiation therapy, and targeted drug delivery enhanced the selectivity and efficacy of anticancer drugs or drug candidates. Therefore, surface-tuned GNMs could be used as sensitive, reliable, and accurate early HMs, metastatic HMs, and MRD-detection tools, as well as selective, potent anticancer agents. However, GNMs may induce endothelial leakage to exacerbate cancer metastasis. Studies using clinical patient samples, patient-derived HMs models, or healthy-animal models could give a precise idea about their theranostic potential as well as biocompatibility. The present review will investigate the theranostic potential of vectorized GNMs in HMs and future challenges before clinical theranostic applications in HMs.

Characteristics and Outcomes of Adult Patients in the PETHEMA Registry with Relapsed or Refractory FLT3-ITD Mutation-Positive Acute Myeloid Leukemia

This retrospective study investigated outcomes of 404 patients with relapsed/refractory (R/R) FMS-like tyrosine kinase 3 (FLT3)-internal tandem duplication (ITD) acute myeloid leukemia (AML) enrolled in the PETHEMA registry, pre-approval of tyrosine kinase inhibitors. Most patients (63%) had received first-line intensive therapy with 3 + 7. Subsequently, patients received salvage with intensive therapy (n = 261), non-intensive therapy (n = 63) or supportive care only (n = 80). Active salvage therapy (i.e., intensive or non-intensive therapy) resulted in a complete remission (CR) or CR without hematological recovery (CRi) rate of 42%. More patients achieved a CR/CRi with intensive (48%) compared with non-intensive (19%) salvage therapy (p < 0.001). In the overall population, median overall survival (OS) was 5.5 months; 1- and 5-year OS rates were 25% and 7%. OS was significantly (p < 0.001) prolonged with intensive or non-intensive salvage therapy compared with supportive therapy, and in those achieving CR/CRi versus no responders. Of 280 evaluable patients, 61 (22%) had an allogeneic stem-cell transplant after they had achieved CR/CRi. In conclusion, in this large cohort study, salvage treatment approaches for patients with FLT3-ITD mutated R/R AML were heterogeneous. Median OS was poor with both non-intensive and intensive salvage therapy, with best long-term outcomes obtained in patients who achieved CR/CRi and subsequently underwent allogeneic stem-cell transplant.

A retrospective comparison of salvage intensive chemotherapy versus venetoclax-combined regimen in patients with relapsed/refractory acute myeloid leukemia (AML)

Background:

Evidence that a venetoclax (VEN)-combined regimen is effective in relapsed/refractory acute myeloid leukemia (R/R AML) is emerging. However, it is unknown how VEN-combined low intensity treatment compares to intensive chemotherapy (IC) in medically fit patients with R/R AML.

Methods:

We compared AML patients who received IC (n = 89) to those who received a VEN in combination with hypomethylating agents or low dose cytarabine (VEN combination) (n = 54) as their first- or second-line salvage after failing anthracycline-containing intensive chemotherapy.

Results:

The median age was 49 years, and significantly more patients in the VEN combination group were in their second salvage and had received prior stem cell transplantation (SCT). Overall response rates including CR, CRi, and MLFS were comparable (44.0% for IC vs. 59.3% for VEN combination, p = 0.081), but VEN combination group compared to IC group tended to show lower treatment related mortality. The rate of bridging to SCT was the same (68.5%), but the percentage of SCT at blast clearance was significantly higher in the VEN-combined group (62.3% vs. 86.5%, p = 0.010). After median follow-up periods of 22.5 (IC) and 11.3 months (VEN combination), the median overall survival was 8.9 (95% CI, 5.4-12.4) and 12.4 months (95% CI, 9.5-15.2) (p = 0.724), respectively.

Conclusion:

VEN combination provides a comparable anti-leukemic response and survival to salvage IC, and provide a bridge to SCT with better disease control in medically-fit patients with R/R AML.

Analysis of efficacy, safety and prognostic factors of DAC-HAA treatment in Chinese pediatric patients with refractory or relapsed acute myeloid leukemia

Hematopoietic stem cell transplantation (HSCT) is generally considered as the only effective treatment for children with relapsed/refractory (R/R) acute myeloid leukemia (AML). Achieving remission prior to HSCT affects the efficacy of the procedure and patient survival; therefore, induction therapy in children with R/R AML prior to HSCT is very important. The aim of the present study was to evaluate the clinical efficacy, prognosis and safety of 5-aza-2-deoxycytidine (DAC) combined with homoharringtonine + cytarabine + aclarubicin (HAA regimen) in the treatment of pediatric R/R AML. A total of 53 pediatric patients with R/R AML, aged 1-14 years, were treated with DAC-HAA. The overall response rate was 83.1%, with a complete remission rate of 77.4% and a partial remission rate of 5.7%. In conclusion, DAC-HAA therapy for children with R/R AML was found to be associated with a high remission rate, a short period of bone marrow suppression and a good safety profile. Therefore, DAC-HAA may be of value as a transitional regimen prior to HSCT and is worthy of clinical consideration.

Gilteritinib versus chemotherapy in Japanese patients with FLT3-mutated relapsed/refractory acute myeloid leukemia

Background

Until recently, no effective targeted therapies for FLT3-mutated (FLT3^mut+) relapsed/refractory (R/R) acute myeloid leukemia (AML) were available in Japan. The FLT3 inhibitor, gilteritinib, was approved in Japan for patients with FLT3^mut+ R/R AML based on the phase 3 ADMIRAL trial, which demonstrated the superiority of gilteritinib over salvage chemotherapy (SC) with respect to overall survival (OS; median OS, 9.3 vs 5.6 months, respectively; hazard ratio, 0.64 [95% confidence interval 0.49, 0.83]; P < 0.001).

Methods

We evaluated the Japanese subgroup (n = 48) of the ADMIRAL trial, which included 33 patients randomized to 120-mg/day gilteritinib and 15 randomized to SC.

Results

Median OS was 14.3 months in the gilteritinib arm and 9.6 months in the SC arm. The complete remission/complete remission with partial hematologic recovery rate was higher in the gilteritinib arm (48.5%) than in the SC arm (13.3%). After adjustment for drug exposure, fewer adverse events (AEs) occurred in the gilteritinib arm than in the SC arm. Common grade ≥ 3 AEs related to gilteritinib were febrile neutropenia (36%), decreased platelet count (27%), and anemia (24%).

Conclusion

Findings in Japanese patients are consistent with those of the overall ADMIRAL study population.

Intensive versus less-intensive antileukemic therapy in older adults with acute myeloid leukemia: A systematic review

To compare the effectiveness and safety of intensive antileukemic therapy to less-intensive therapy in older adults with acute myeloid leukemia (AML) and intermediate or adverse cytogenetics, we searched the literature in Medline, Embase, and CENTRAL to identify relevant studies through July 2020. We reported the pooled hazard ratios (HRs), risk ratios (RRs), mean difference (MD) and their 95% confidence intervals (CIs) using random-effects meta-analyses and the certainty of evidence using the GRADE approach. Two randomized trials enrolling 529 patients and 23 observational studies enrolling 7296 patients proved eligible. The most common intensive interventions included cytarabine-based intensive chemotherapy, combination of cytarabine and anthracycline, or daunorubicin/idarubicin, and cytarabine plus idarubicin. The most common less-intensive therapies included low-dose cytarabine alone, or combined with clofarabine, azacitidine, and hypomethylating agent-based chemotherapy. Low certainty evidence suggests that patients who receive intensive versus less-intensive therapy may experience longer survival (HR 0.87; 95% CI, 0.76-0.99), a higher probability of receiving allogeneic hematopoietic stem cell transplantation (RR 6.14; 95% CI, 4.03-9.35), fewer episodes of pneumonia (RR, 0.25; 95% CI, 0.06-0.98), but a greater number of severe, treatment-emergent adverse events (RR, 1.34; 95% CI, 1.03-1.75), and a longer duration of intensive care unit hospitalization (MD, 6.84 days longer; 95% CI, 3.44 days longer to 10.24 days longer, very low certainty evidence). Low certainty evidence due to confounding in observational studies suggest superior overall survival without substantial treatment-emergent adverse effect of intensive antileukemic therapy over less-intensive therapy in older adults with AML who are candidates for intensive antileukemic therapy.

Retrospective Analysis of Adult Patients With Relapsed/Refractory Acute Myeloid Leukemia Treated with FLAG at a Comprehensive Cancer Center

BACKGROUND

FLAG ± Ida (fludarabine, cytarabine, granulocyte colony-stimulating factor, and idarubicin), is a salvage chemotherapy regimen for relapsed or refractory (R/R) acute myeloid leukemia (AML), with complete remission (CR) rates historically ranging from 52% to 63%. We review the outcomes for patients with R/R AML treated with FLAG ± Ida at the University of California Davis Comprehensive Cancer Center.

PATIENTS AND METHODS

Adult patients (≥ 18 years) with R/R AML who received FLAG or FLAG + Ida from January 1, 2012 to October 31, 2016 were identified via chart review. Outcomes evaluated were CR, CR with incomplete hematologic recovery (CRi), overall response rate, overall survival (OS), relapse-free survival, and adverse events.

RESULTS

Forty-two patients were included. The median age was 52 years (range, 23-73 years), and 57% were male. Sixteen (38.1%) patients had relapsed disease, and 26 (61.9%) had refractory disease. Most (n = 35; 83.3%) patients had European LeukemiaNet intermediate-risk AML. Responses were CR in 20 (47.6%) and CRi in 6 (14.3%). The median OS was 10 months (range, 0.8-51 months), and the median relapse-free survival was 12 months (range, 1-51 months) for responders. The median OS for patients who achieved CR was not reached, and the estimated 48-month survival rate was 56%. The median OS after CRi or no response was 3.47 and 2.17 months, respectively. The median OS was not significantly different when censored for stem cell transplant following chemotherapy, nor with use/deferral of idarubicin. The most common adverse effects were pancytopenia and infection.

CONCLUSION

Patient outcomes after treatment with FLAG ± Ida for R/R AML remain similar to prior reports, confirming its role as a salvage regimen for these patients.

Propensity-score Matched Comparison of Salvage Chemotherapy Regimens in Relapsed/Refractory Acute Myeloid Leukemia

BACKGROUND

Relapsed/refractory acute myeloid leukemia (AML) confers a poor prognosis, and there is no single standard of care first-line salvage regimen. FLAG (fludarabine, cytarabine, and granulocyte colony-stimulating factor) is a common salvage regimen with a favorable toxicity and efficacy profile in poor-risk AML.

MATERIALS AND METHODS

We conducted a single-center, retrospective analysis of first relapse/primary refractory patients with AML that received salvage chemotherapy from January 2009 to July 2019. We propensity-score matched patients 1:1 (based on age at diagnosis, cytogenetic risk group, Charlson comorbidity index, de novo vs. secondary AML, and whether or not they received an allogeneic stem cell transplant in first complete remission) into 2 groups, FLAG (Group 1) or non-FLAG (Group 2) as first-line salvage regimen, with 66 patients in each group. The primary endpoint was overall response rate (complete response and complete response with incomplete hematologic recovery).

RESULTS

The median patient age was 59 years (range, 19-80 years). Patients treated with FLAG had a higher overall response rate (complete response/complete response with incomplete hematologic recovery) (71.2% vs. 50.0%; odds ratio, 2.47; 95% confidence interval [CI], 1.21-5.08; P = .013), longer event-free survival (8.9 vs. 2.1 months; hazard ratio [HR], 0.58; 95% CI, 0.39-0.86; P = .005), and longer overall survival (14.2 vs. 5.9 months; HR, 0.62; 95% CI, 0.41-0.93; P = .019). Patients who received FLAG had a shorter median duration of neutropenia (22 vs. 34 days; HR, 0.43; 95% CI, 0.29-0.64; P < .001).

CONCLUSION

This analysis supports the FLAG regimen as an effective and well-tolerated salvage therapy for patients with relapsed/refractory AML.

Current and Emerging Therapies for Acute Myeloid Leukemia

Acute myeloid leukemia (AML) is predominantly a disease of older adults and the majority of affected patients succumb to the disease. After decades of slow progress, the last 5 years have witnessed remarkable progress in AML therapy with the approval of multiple highly active and well-tolerated novel therapies. Notable among these are agents targeting driver mutations including FLT3, IDH1/2 as well as the Bcl-2 inhibitor venetoclax. The combination of hypomethylating agents with venetoclax is highly active in AML and has become the standard of care for older patients as well as those with comorbidities. As a result of these advances, a larger proportion of AML patients now achieve complete remissions enabling them to undergo allogeneic hematopoietic cell transplantation with curative intent. Progress is also being made in the field of monoclonal antibodies targeting leukemia antigens and other immunotherapies and many such agents are currently under active investigation.

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.

Pegylated interferon-2α invokes graft-versus-leukemia effects in patients relapsing after allogeneic stem cell transplantation

Allogeneic stem cell transplantation (SCT) is a curative therapy for patients with hematological malignancies related largely to an immunological graft-versus-leukemia (GVL) effect mediated by donor T cells and natural killer cells. Relapse of disease after SCT represents failure of GVL and is now the major cause of treatment failure. We sought to augment GVL effects in patients (n = 29) relapsing after SCT in a prospective phase I/II clinical trial of dose-escalated pegylated interferon-2α (peg-IFNα). The administration of peg-IFNα after reinduction chemotherapy, with or without subsequent donor lymphocyte infusion (DLI), resulted in a 2-year overall survival (OS) of 31% (95% confidence interval, 17.3%-49.2%), which rejects the null hypothesis of 7% generated by observations in an institutional historical cohort. As expected, peg-IFNα was associated with graft-versus-host disease (GVHD) and hematological toxicity, which was manageable with scheduled dose modifications. Progression-free survival (PFS) was greatest in patients who experienced GVHD, although the majority of those patients still eventually progressed. Higher PFS and OS were associated with pretreatment proportions of immune cell populations with regulatory function, including mucosal invariant T cells, regulatory T cells, and plasmacytoid dendritic cells, independent of any association with GVHD. Peg-IFNα administration after relapse thus constitutes a logical strategy to invoke GVL effects and should be studied in a larger, multicenter cohort. This trial was registered at www.anzctr.org.au as #ACTRN12612000728831.

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.

Long-term follow-up of Cladribine, high-dose Cytarabine, and Idarubicin as salvage treatment for relapsed acute myeloid leukemia and literature review

PURPOSE

Outcome for relapsed acute myeloid leukemia (AML) is poor. Cladribine has activity in AML, and an enhancing effect on other cytostatic drugs thus may help overcome resistance. Here, we present the final analysis of our phase II trial evaluating safety and efficacy of cladribine, cytarabine, and idarubicin (CAI) in relapsed AML.

METHODS

Patients with relapsed AML after at least 6 months remission received two courses of CAI. After 9 patients, prolonged neutropenia prompted protocol change (omission of idarubicin in 2nd course and dose-reduction of cytarabine). Primary endpoints were remission rate and safety.

RESULTS

Twenty patients received treatment, fourteen one, and six two courses CAI/CA. After first course, complete remission (CR/CRi) was achieved in 60%. Most frequent toxicity was infection. Median OS was 8.8 months in all patients and 21.1 months in those with CR. Nine patients (48%) proceeded to allogeneic stem cell transplantation (allo-SCT), four of those are still alive and in CR, accounting for a 5-year survival rate of 55% of transplanted patients.

CONCLUSION

Cladribine, cytarabine, and idarubicin in relapsed AML is feasible and induces good response rates. As expected, infections are the most important complication. However, combined with allo-SCT, long-term survival can be achieved in a substantial number of patients.

The role of cladribine in acute myeloid leukemia: an old drug up to new tricks

Despite advances in understanding the pathogenesis of acute myeloid leukemia (AML), the standard therapy remained nearly unchanged for several decades. There have been many efforts to improve the response and survival by either increasing the cytarabine (ARA-C) dose or adding a third agent to the standard chemotherapy regimen. Several studies have evaluated the addition of cladribine (CdA) to standard induction, exploiting its property to potentiate ARA-C uptake. Response rates for combination regimens including CdA in relapsed/refractory (R/R) adults are approximately 50% and approximately 70% in de novo AML. Recently, a low intensity combination of CdA and ARA-C alternating with decitabine has shown promising results in older patients with AML. In this review, we will discuss the role of CdA in the treatment of AML, summarizing the recent clinical data regarding its incorporation into the induction therapy for adult AML.

Gilteritinib or Chemotherapy for Relapsed or Refractory FLT3-Mutated AML

BACKGROUND

Patients with relapsed or refractory acute myeloid leukemia (AML) with mutations in the FMS-like tyrosine kinase 3 gene (FLT3) infrequently have a response to salvage chemotherapy. Gilteritinib is an oral, potent, selective FLT3 inhibitor with single-agent activity in relapsed or refractory FLT3-mutated AML.

METHODS

In a phase 3 trial, we randomly assigned adults with relapsed or refractory FLT3-mutated AML in a 2:1 ratio to receive either gilteritinib (at a dose of 120 mg per day) or salvage chemotherapy. The two primary end points were overall survival and the percentage of patients who had complete remission with full or partial hematologic recovery. Secondary end points included event-free survival (freedom from treatment failure [i.e., relapse or lack of remission] or death) and the percentage of patients who had complete remission.

RESULTS

Of 371 eligible patients, 247 were randomly assigned to the gilteritinib group and 124 to the salvage chemotherapy group. The median overall survival in the gilteritinib group was significantly longer than that in the chemotherapy group (9.3 months vs. 5.6 months; hazard ratio for death, 0.64; 95% confidence interval [CI], 0.49 to 0.83; P<0.001). The median event-free survival was 2.8 months in the gilteritinib group and 0.7 months in the chemotherapy group (hazard ratio for treatment failure or death, 0.79; 95% CI, 0.58 to 1.09). The percentage of patients who had complete remission with full or partial hematologic recovery was 34.0% in the gilteritinib group and 15.3% in the chemotherapy group (risk difference, 18.6 percentage points; 95% CI, 9.8 to 27.4); the percentages with complete remission were 21.1% and 10.5%, respectively (risk difference, 10.6 percentage points; 95% CI, 2.8 to 18.4). In an analysis that was adjusted for therapy duration, adverse events of grade 3 or higher and serious adverse events occurred less frequently in the gilteritinib group than in the chemotherapy group; the most common adverse events of grade 3 or higher in the gilteritinib group were febrile neutropenia (45.9%), anemia (40.7%), and thrombocytopenia (22.8%).

CONCLUSIONS

Gilteritinib resulted in significantly longer survival and higher percentages of patients with remission than salvage chemotherapy among patients with relapsed or refractory FLT3-mutated AML. (Funded by Astellas Pharma; ADMIRAL ClinicalTrials.gov number, NCT02421939.).

FLAG/FLAG-IDA regimen for children with relapsed/refractory acute leukemia in the era of targeted novel therapies

BACKGROUND

Outcomes of relapsed/refractory childhood acute leukemia remain poor. We analyzed the safety/efficacy of fludarabine, cytarabine, and granulocyte colony stimulating factor, with/without idarubicin (FLAG ± IDA) as salvage therapy compared with recent published results of novel therapies.

METHODS

This retrospective study included children aged 1 to 15 years with relapsed/refractory acute leukemia who received FLAG ± IDA salvage therapy from January 2000 to December 2014. Patients with infant leukemia, mixed lineage leukemia, Philadelphia-positive acute leukemia, or secondary leukemia were excluded.

RESULT

Fifty patients were identified: 25 with acute lymphoblastic leukemia and 25 with acute myeloid leukemia. The median age at initiation of FLAG ± IDA was seven years. Site of relapse was the bone marrow in 29, isolated central nervous system in 11, and combined in 10 patients. FLAG ± IDA was used after first relapse in 68% and after multiple relapses in 32%. Complete remission was achieved in 34 (68%) patients. No variables predictive of complete remission were identified. Grade 3 or greater toxicity was observed in 96% and 6% died from toxicity. Toxicities included hematologic toxicity (96%), infection (52%), and enterocolitis (28%). Twenty-four of 50 (48%) patients achieved a sustained complete remission and survived to bone marrow transplantation. The five-year overall survival was 23.9% ± 6.9%. Patients achieving second complete remission and patients proceeding to bone marrow transplantation following second complete remission demonstrated significantly improved overall survival (p = 0.001).

CONCLUSION

Despite a 68% complete remission rate using FLAG ± IDA, only 48% of patients survived to bone marrow transplantation. The regimen was associated with 96% toxicity and only one in four patients was alive at five years. This underscores the need to find more effective lower toxicity salvage regimens.

Cytotoxic therapy in acute myeloid leukemia: not quite dead yet

Given the recent approvals of new agents for acute myeloid leukemia (AML), a clinical trial pipeline stocked with novel therapies, and the rapid integration of imaginative approaches in diseases like acute lymphocytic leukemia and chronic lymphocytic leukemia, it is reasonable to ask whether treatment of AML might finally depart from the classical cytotoxic induction therapy that has been employed since the 1970s. However, for better or worse, in 2018, cytotoxic induction regimens remain the standard of care for most patients. Indeed, the future likely lies in combinations of therapies that act with a spectrum of mechanisms. Using a case-based format, this review will outline current treatment expectations for patients according to karyotypic risk and familiarize readers with the basis for common induction choices. Relapsed/refractory disease may be especially amenable to interventions with novel agents or clinical trials; however, there are still some patients who most benefit from intensive chemotherapy. This review will outline risk systems that help the practitioner identify those with the best chances for response and survival. Finally, clinical tools, including geriatric assessments and comorbidity calculators, may help clinicians recognize patients for whom disease risk and comorbidity tip the balance against classical chemotherapy, a frequent challenge for those who treat this devastating disease.

New approaches in allogenic transplantation in AML

Acute myeloid leukemia (AML) is a heterogeneous disorder with high morbidity and mortality. Allogeneic stem cell transplantation (allo-SCT) is an effective, and sometimes the only, curative postremission therapy for AML patients. Based on genetic risk classification, the published data have suggested that allo-SCT be recommended for high- and most intermediate-risk AML but not for low-risk AML in first complete remission (CR1). Recently, the role of allo-SCT in low-risk AML in CR1 is being established with the development of a risk-directed, minimal residual disease-based strategy. Though human leukocyte antigen-matched sibling transplantation remains the preferred therapeutic option for AML, modern approaches and developments pre-, peri- and post-transplant have facilitated other transplant modalities, especially haploidentical SCT, as promising valid alternative choices. In this paper, we review recent advances in allo-SCT for AML, weigh the benefits of allo-SCT for high-, intermediate-, and even low-risk AML in CR1, discuss the best choice of allo-SCT donor for the treatment of AML, and summarize new approaches for refractory and relapsed AML pre- or post-allo-SCT.

Re-induction chemotherapy using FLAG-mitoxantrone for adult patients with relapsed acute leukemia: a single-center experience from United Arab Emirates

We studied the outcome of 47 adult patients with relapsed acute leukaemia (AML = 25 and ALL = 22) treated with FLAG-mitoxantrone regimen. Median time to relapse was 10.7 months (range 1.9-27.7). Complete remission (CR2) was 60.1% which was significantly more frequent in ALL compared to AML (P = 0.049). WBC count < 100 × 10⁹/L at initial diagnosis and time to relapse > 1 year were significantly predictor for CR2 in AML (P = 0.005 for both). Induction death was significantly higher in ALL compared to AML (P = 0.039). Median follow-up was 4.0 months (0.9-119.8) for AML and 2.1 months (range 0.6-118.1) for ALL. Nine patients underwent allogeneic stem-cell transplantation (allo-SCT). Estimated overall survival (OS) at 12 and 18 months was 60.5 and 34.6%, respectively, for AML, and 39.9 and 29.9%, respectively, for ALL. For AML patients failure to achieve CR, WBC count at initial diagnosis > 5 × 10⁹/L and poor cytogenetic risk group was significant predictors of poor OS (P = 0.010, P = 0.025, and P = 0.015, respectively). For ALL patients failure to achieve of CR, WBC count at relapse < 5 × 10⁹/L (CR patients) and lack of any type of consolidation therapy were significant predictor of poor OS (P < 0.001, P = 0.008, P = 0.008, respectively).

A phase I-II study of plerixafor in combination with fludarabine, idarubicin, cytarabine, and G-CSF (PLERIFLAG regimen) for the treatment of patients with the first early-relapsed or refractory acute myeloid leukemia

Clinical outcomes of patients with acute myeloid leukemia (AML) showing the first primary refractory or early-relapsed disease remain very poor. The Programa Español de Tratamientos en Hematología (PETHEMA) group designed a phase I-II trial using FLAG-Ida (fludarabine, idarubicin, cytarabine, and G-CSF) plus high-dose intravenous plerixafor, a molecule inducing mobilization of blasts through the SDF-1α-CXCR4 axis blockade and potentially leading to chemosensitization of the leukemic cells. We aimed to establish a recommended phase 2 dose (RP2D) of plerixafor plus FLAG-Ida, as well as the efficacy and safety of this combination for early-relapsed (first complete remission (CR/CRi) < 12 months) or primary refractory AML. Between 2012 and 2015, 57 patients were enrolled, and 41 received the RP2D (median age 52 years [range, 18-64]). Among these patients, 20 (49%) achieved CR/CRi, and 3 (7%) died during induction. CR/CRi rate was 50% (13/26) among primary refractory and 47% (7/15) among early relapse. Overall, 25 patients (61%) were allografted. Median overall and disease-free survivals were 9.9 and 13 months, respectively. In summary, the combination of plerixafor plus FLAG-Ida resulted in a relatively high CR/CRi rate in adult patients with primary refractory or early relapsed AML, with an acceptable toxicity profile and induction mortality rate, bridging the majority of patients to allogeneic stem cell transplantation. ClinicalTrials.gov Identifier: NCT01435343.

Outcomes of previously untreated elderly patients with AML: a propensity score-matched comparison of clofarabine vs. FLAG

The 5-year overall survival (OS) in patients ≥ 60 years old with acute myeloid leukemia (AML) remains < 10%. Clofarabine-based induction (CLO) provides an alternative to low-intensity therapy (LIT) and palliative care for this population, but supporting data are conflicted. Recently, our institution adopted the FLAG regimen (fludarabine, cytarabine, and granulocyte colony-stimulating factor) based on data reporting similar outcomes to CLO in elderly patients with AML unable to tolerate anthracycline-based induction. We retrospectively analyzed the efficacy and safety of patients ≥ 60 years old with AML treated with FLAG or CLO over the past 10 years. We performed a propensity score match that provided 32 patients in each group. Patients treated with FLAG had a higher CR/CRi rate (65.6 vs. 37.5%, P = 0.045) and OS (7.9 vs. 2.8 months, P = 0.085) compared to CLO. Furthermore, FLAG was better tolerated with significantly less grade 3/4 toxicities and a shorter duration of neutropenia (18.5 vs. 30 days, P = 0.002). Finally, we performed a cost analysis that estimated savings to be $30,000-45,000 per induction with FLAG. Our study supports the use of FLAG both financially and as an effective, well-tolerated high-dose treatment regimen for elderly patients with AML. No cases of cerebellar neurotoxicity occurred.

Vosaroxin in relapsed/refractory acute myeloid leukemia: efficacy and safety in the context of the current treatment landscape

Treatment for acute myeloid leukemia (AML) generally consists of a combination of cytarabine and an anthracycline. Although induction therapy leads to complete remission (CR) for most patients, refractoriness to chemotherapy or relapse after initial response is associated with poor outcomes. The 1-year survival rates after first relapse have been reported at 29%, declining to 11% at 5 years. Prognosis is particularly poor among older patients whose higher prevalence of unfavorable cytogenetics and high frequency of comorbidities diminish their ability to tolerate intensive chemotherapy. There is no standard of care for relapsed/refractory (R/R) AML, and no new therapies have shown consistently superior outcomes in this setting in over two decades. Vosaroxin is an anticancer quinolone derivative (AQD) that was evaluated in combination with cytarabine for the treatment of R/R AML in the randomized, double-blind, placebo-controlled, phase III VALOR study (n = 711). Compared with placebo/cytarabine, the vosaroxin/cytarabine regimen demonstrated favorable CR rates and survival in patients ⩾60 years of age, with toxicities similar to other AML regimens. Here we review outcomes of recent studies of commonly used chemotherapy regimens for the treatment of R/R AML and evaluate the results of the VALOR trial in the context of the current treatment landscape.

Effect of granulocyte colony-stimulating factor on outcomes in patients with non-M3 acute myelogenous leukemia treated with anthracycline-based induction (7+3 regimen) chemotherapies

We analyzed the effects of granulocyte colony-stimulating factor (G-CSF) on outcomes in 315 anthracycline-based induction chemotherapy-treated patients with non-M3 acute myelogenous leukemia (AML). Patients were classified as follows: no G-CSF administration during induction (no G-CSF group; 112 patients); administration immediately upon neutropenia onset (absolute neutrophil counts (ANC)<1000/μL), but before febrile neutropenia (preemptive group; 74 patients); and administration following febrile neutropenia development (therapeutic group; 129 patients). G-CSF users had a shorter time to ANC recovery than the no G-CSF group (p<0.001). The chemotherapy-induced febrile neutropenia (CIFN) duration was significantly shorter in the preemptive group than in other groups (p<0.001). The incidence of CIFN was not significantly different between preemptive and non-G-CSF users (84.8% versus 82.4%). Preemptive G-CSF administration modestly improved treatment-related mortality (TRM), compared with no G-CSF administration (p=0.076 in multivariate analysis). G-CSF administration did not affect relapse-free or overall survivals or the cumulative relapse incidence among the groups. In conclusion, preemptive G-CSF administration reduced CIFN duration and modestly improved TRM without affecting chemotherapy outcomes. These effects were not observed in the therapeutic group; therefore, initiation of G-CSF during induction therapy before the development of febrile neutropenia may be desirable.

Efficacy of single-agent decitabine in relapsed and refractory acute myeloid leukemia

Improving therapy for relapsed/refractory AML remains a challenge. We performed a retrospective analysis of outcomes following decitabine treatment in 34 patients with relapsed/refractory AML (median age, 62; median Charlson comorbidity score, 6). Decitabine, 20 mg/m² daily, was given in 5- (25%) or 10-day (75%) cycles. Overall response rate (OR) was 30% with 21% complete remission and 9% partial remission rate. Patients with therapy-related myeloid neoplasm (t-MN) and secondary AML had a significantly higher OR compared to those with de novo AML (70 vs. 30%; p = .02). Median overall survival of all patients was 8.5 months. Median survival in patients with t-MN or secondary AML was 12.4 months compared to 8 months in those with de novo AML (p = .20). Fifteen (44%) patients proceeded to hematopoietic stem cell transplant. These data support using 10-day treatment cycles of decitabine in patients with relapsed/refractory AML, particularly for those with secondary or therapy-related AML.

Impact of salvage regimens on response and overall survival in acute myeloid leukemia with induction failure

We evaluated the impact of salvage regimens and allogeneic hematopoietic cell transplantation (allo-HCT) in acute myeloid leukemia (AML) with induction failure. Between 1993 and 2009, 3324 patients with newly diagnosed AML were enrolled in 5 prospective treatment trials of the German-Austrian AML Study Group. After first induction therapy with idarubicin, cytarabine and etoposide (ICE), 845 patients had refractory disease. In addition, 180 patients, although responding to first induction, relapsed after second induction therapy. Of the 1025 patients with induction failure, 875 (median age 55 years) received intensive salvage therapy: 7+3-based (n=59), high-dose cytarabine combined with mitoxantrone (HAM; n=150), with all-trans retinoic acid (A; A-HAM) (n=247), with gemtuzumab ozogamicin and A (GO; GO-A-HAM) (n=140), other intensive regimens (n=165), experimental treatment (n=27) and direct allo-HCT (n=87). In patients receiving intensive salvage chemotherapy (n=761), response (complete remission/complete remission with incomplete hematological recovery (CR/CRi)) was associated with GO-A-HAM treatment (odds ratio (OR), 1.93; P=0.002), high-risk cytogenetics (OR, 0.62; P=0.006) and age (OR for a 10-year difference, 0.75; P<0.0001). Better survival probabilities were seen in an extended Cox regression model with time-dependent covariables in patients responding to salvage therapy (P<0.0001) and having the possibility to perform an allo-HCT (P<0.0001). FLT3 internal tandem duplication, mutated IDH1 and adverse cytogenetics were unfavorable factors for survival.

Cladribine, cytarabine and idarubicin (CLA-Ida) salvage chemotherapy in relapsed acute myeloid leukemia (AML)

BACKGROUND

The prognosis for relapsing AML patients is disappointing and the preferred salvage chemotherapy is unclear. Among other regimens, cladribine, cytarabine, and idarubicin (CLA-Ida) is used.

METHODS

We analyzed relapsing AML patients receiving CLA-Ida chemotherapy between July 2012 and April 2015 at three academic centers in Switzerland.

RESULTS

Thirty-four patients underwent at least one cycle of CLA-Ida chemotherapy, with 6 patients having two cycles. Treatment-related mortality was 5.9% (2/34 patients). Eighteen patients (52.9%) achieved a complete remission (CR2), and 16 (47.1%) received subsequent allogeneic transplantation, with 8 (23.5%) of these patients remaining in complete remission after a median follow-up of 6 months. In contrast, all 16 patients not achieving CR2 died within 12 months after relapse due to progressive disease.

CONCLUSION

Our data suggest a promising rate of complete remission following CLA-Ida salvage treatment in relapsing AML patients enabling a substantial proportion of such patients to proceed to allogeneic transplantation.

Successful use of high-dose cytarabine in a patient with acute myeloid leukemia and severe hepatic dysfunction

Acute myeloid leukemia is a hematologic malignancy characterized by the clonal expansion of myeloid blasts in the peripheral blood, bone marrow, and other tissues. Prognosis is poor with 5-year survival rates ranging from 5–65% depending on demographic and clinical features. Outcomes are worse for patients that have an antecedent myeloproliferative neoplasm that evolves to acute myeloid leukemia, with a survival rate of <10%. Treatment for acute myeloid leukemia has remained cytarabine and an anthracycline given in the standard 3 + 7 regimen. However, for patients with liver dysfunction this regimen, among many others, cannot be given safely. There is currently a lack of data regarding the use of cytarabine in patients with severe hepatic dysfunction. In this case report, we present a patient with secondary acute myeloid leukemia who successfully received a modified regimen of high-dose cytarabine while in severe hepatic dysfunction (bilirubin >15 mg/dL).

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.

How I treat refractory and early relapsed acute myeloid leukemia

Between 10% and 40% of newly diagnosed patients with acute myeloid leukemia (AML) do not achieve complete remission with intensive induction therapy and are therefore categorized as primary refractory or resistant. Few of these patients can be cured with conventional salvage therapy. They need to be evaluated regarding eligibility for allogeneic hematopoietic stem cell transplantation (HSCT) as this is currently the treatment with the highest probability of cure. To reduce the leukemia burden prior to transplantation, salvage chemotherapy regimens need to be employed. Whenever possible, refractory/relapsed patients should be enrolled in clinical trials as we do not have highly effective and standardized treatments for this situation. Novel therapies include tyrosine kinase inhibitors, small-molecule inhibitors (eg, for Polo-like kinase 1 and aminopeptidase), inhibitors of mutated isocitrate dehydrogenase (IDH) 1 and IDH2, antibody-based therapies, and cell-based therapies. Although the majority of these therapies are still under evaluation, they are likely to enter clinical practice rapidly as a bridge to transplant and/or in older, unfit patients who are not candidates for allogeneic HSCT. In this review, we describe our approach to refractory/early relapsed AML, and we discuss treatment options for patients with regard to different clinical conditions and molecular profiles.

Revisiting the role of cladribine in acute myeloid leukemia: an improvement on past accomplishments or more old news?

Originally studied in lymphoid diseases, cladribine (CdA) is an adenosine deaminase resistant analog of adenosine that was later discovered to induce myeloid cell apoptosis. The activity of CdA in myeloid malignancies was first reported in relapsed/refractory (RR) pediatric acute myeloid leukemia (AML) with complete response (CR) rates of up to 47%. Consequently, several studies have confirmed the efficacy of single agent CdA or CdA combination regimens in AML. Established CR rates for combination regimens in RR adults are approximately 50%, while CR rates for newly diagnosed (ND) adults are approximately 70% and show similar toxicity profiles to previously used regimens. Despite these promising data, many centers have yet to adopt CdA combination regimens for these difficult to treat populations. We review the pharmacology, pharmacokinetics, clinical data, and safety of CdA monotherapy and combination regimens for the management of pediatric and adult ND and RR-AML.

Retrospective comparison of fludarabine in combination with intermediate-dose cytarabine versus high-dose cytarabine as consolidation therapies for acute myeloid leukemia

This retrospective study compared efficacy and safety of fludarabine combined with intermediate-dose cytarabine (FA regimen) versus high-dose cytarabine (HiDAC regimen) as consolidation therapy in acute myeloid leukemia (AML) patients who achieved complete remission. Disease-free survival (DFS) and overall survival (OS) based on age (≥ 60, <60 years) and cytogenetics were evaluated from data between January 2005 and March 2013. Total 82 patients (FA, n = 45; HiDAC, n = 37; 14-65 years) were evaluated. Five-year DFS was 32.0% and 36.2% for FA and HiDAC groups, respectively (P = 0.729), and 5-year OS was 39.5% and 47.8% (P = 0.568), respectively. Among older patients (≥ 60 years), 3-year DFS was 26.0% for FA group and 12.5% for HiDAC group (P = 0.032), and 3-year OS was 34.6% and 12.5%, respectively (P = 0.026). In FA group, hematological toxicities were significantly lower. FA regimen was as effective as HiDAC regimen in patients with good/intermediate cytogenetics and significantly improved DFS and OS in older patients.

Salvage therapy with mitoxantrone, etoposide and cytarabine in relapsed or refractory acute lymphoblastic leukemia

The survival of patients with relapsed or refractory acute lymphoblastic leukemia (ALL) is poor. We performed a retrospective analysis of 40 patients treated with five days of mitoxantrone 8mg/m(2)/day, etoposide 100mg/m(2)/day, and cytarabine 1000mg/m(2)/day (MEC). The complete remission rate was 30% and median remission duration was 11.2 months. Median overall survival was 6.5 months. In univariate analysis, patients in first relapse had improved overall survival compared to ≥second relapse (p=0.02). Thirty-day mortality rate was 7.5%. In relapsed or refractory ALL, MEC demonstrated moderate activity, but did not improve survival compared to published salvage chemotherapy regimens.

International Randomized Phase III Study of Elacytarabine Versus Investigator Choice in Patients With Relapsed/Refractory Acute Myeloid Leukemia

Purpose

Most patients with acute myeloid leukemia (AML) eventually experience relapse. Relapsed/refractory AML has a dismal prognosis and currently available treatment options are generally ineffective. The objective of this large, international, randomized clinical trial was to investigate the efficacy of elacytarabine, a novel elaidic acid ester of cytarabine, versus the investigator's choice of one of seven commonly used AML salvage regimens, including high-dose cytarabine, multiagent chemotherapy, hypomethylating agents, hydroxyurea, and supportive care.

Patients and Methods

A total of 381 patients with relapsed/refractory AML were treated in North America, Europe, and Australia. Investigators selected a control treatment for individual patients before random assignment. The primary end point was overall survival (OS).

Results

There were no significant differences in OS (3.5 v 3.3 months), response rate (23% v 21%), or relapse-free survival (5.1 v 3.7 months) between the elacytarabine and control arms, respectively. There was no significant difference in OS among any of the investigator's choice regimens. Prolonged survival was only achieved in a few patients in both study arms whose disease responded and who underwent allogeneic stem-cell transplantation.

Conclusion

Neither elacytarabine nor any of the seven alternative treatment regimens provided clinically meaningful benefit to these patients. OS in both study arms and for all treatments was extremely poor. Novel agents, novel clinical trial designs, and novel strategies of drug development are all desperately needed for this patient population.

Elacytarabine in relapsed/refractory acute myeloid leukaemia: an evaluation of clinical efficacy, pharmacokinetics, cardiac safety and effects on lipid profile

Elacytarabine is the elaidic acid ester derivative of cytarabine, designed to enter cells independently of nucleoside transporters. Effects of elacytarabine on QT interval, serum lipid profile and clinical activity were investigated in 43 relapsed/refractory AML patients. Mean maximum increase in corrected QT interval of 24( ± 29)ms occurred 48 h after elacytarabine infusion without associated arrhythmias or clinical symptoms. A non-clinically significant, elacytarabine exposure-dependent increase in cholesterol was caused by a cholesterol rich lipoprotein depleted of apolipoprotein B formed by infused phospholipids complexing cholesterol. Elacytarabine is clinically active in relapsed/refractory AML: overall response rate (CR + CRi) was 44% (16/36 with 7 non-evaluable patients) and adverse events were manageable. Clinical Trials.gov Identifier: NCT01258816.

Timed-sequential chemotherapy as induction and/or consolidation regimen for younger adults with acute myelogenous leukemia

Increasing the intensity of induction chemotherapy has generated considerable recent interest in the treatment of acute myeloid leukemia. Achieving complete remission is a sine qua non condition for prolonged disease-free survival and may affect long-term outcome. In this setting, administering a repeat course of induction shortly after completion of the first course, known as timed-sequential chemotherapy (TSC), has been tested and may lead to an improved long-term outcome. Whether these results are due to the biologic recruitment of cell cycle-specific agents is unknown. However, this strategy to intensify induction may lead to more profound myelosuppression and to potential toxicities. Here we review the results of timed-sequential chemotherapy, used as induction regimen in de novo, relapsed or refractory AML or used as post-remission therapy, and compare them with those from other types of regimens.

Update on optimal management of acute myeloid leukemia

Acute myeloid leukemia (AML) represents a malignant accumulation of immature myeloid cells in the marrow, presenting with impaired hematopoiesis and its attendant complications, including bleeding, infection, and organ infiltration. Chromosomal abnormalities remain the most powerful predictors of AML prognosis and help to identify a subgroup with favorable prognosis. However, the majority of AML patients who are not in the favorable category succumb to the disease. Therefore, better efforts to identify those patients who may benefit from more aggressive and investigational therapeutic approaches are needed. Newer molecular markers aim at better characterizing the large group of intermediate-risk patients and to identify newer targets for therapy. A group that has seen little improvement over the years is the older AML group, usually defined as age ≥ 60. Efforts to develop less intensive but equally efficacious therapy for this vulnerable population are underway.

The thorny issue of relapsed acute myeloid leukemia

PURPOSE OF REVIEW

Acute myeloid leukemia (AML) is a devastating disease, in which the majority of afflicted patients eventually experience relapse and die from their disease.

RECENT FINDINGS

Clinical and molecular characterization of the disease have greatly aided in prognostication in both primary and relapsed settings, which may broadly guide therapy, but truly effective standards of care for relapsed AML remain lacking. Traditional chemotherapeutic drugs have modest but limited efficacy in relapsed AML, whereas more novel and potent cytotoxic chemotherapeutic agents hold promise and are entering the advanced phases of testing. Targeted therapies for AML have demonstrated activity, often as single agents, generating enthusiasm for further development in subgroups of patients with appropriate molecular anomalies. Finally, allogeneic stem cell transplantation continues to evolve as an effective and potentially curative therapy for limited numbers of patients with relapsed AML.

SUMMARY

The complexity of relapsed AML will dictate the need for continued development of novel chemotherapeutic and targeted therapies that suit the molecular and clinical profiling of individual patients.

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.

The Efficacy of Fludarabine, High Dose Cytosine Arabinoside with Granulocyte Colony Stimulating Factor (FLAG) Protocol as Salvage Therapy for Refractory/Relapsed Acute Leukemias in Adult Iraqi Patients

Refractory/relapsed acute leukemia has always been a challenging problem for hematologist. Over the past decade emphasis has been made in the development of regimens containing fludarabine, combined with cytosine arabinoside for the treatment of refractory/relapsed acute leukemias. The aim of this study is to evaluate the efficacy and toxicity of the combination of fludarabine, high dose cytarabine, and granulocyte colony stimulating factor in refractory relapsed cases of acute leukaemia, a prospective study is being conducted at the National Center of Hematology and hematology unit/Baghdad teaching hospital from July 2008 to July 2010. Twenty Patients with refractory/relapsed acute leukemia were treated with fludarabine 30 mg/m(2) and cytosine arabinoside (Ara-C) 2 g/m(2) for 5 days, and granulocyte colony stimulating factor G-CSF 300 µg/day from day 0 till neutrophil recovery (ANC > 1.0 × 10(9)/L). Response was evaluated by bone marrow examination on day 30 post chemotherapy. Patients included were refractory acute lymphoblastic leukemia (ALL) (five patients), relapsed ALL (four patients), refractory acute myeloid leukemia (AML) (eight patients), relapsed AML (three patients). Complete remission (CR) was achieved in nine (45 %) patients, while three (15 %) patients got partial remission. Three (15 %) patients died because of post chemotherapy complications and five (25 %) patient failed to achieve remission. Major complications encountered were: anemia, fever, bleeding, mucositis and bacterial infections. FLAG protocol is well tolerated and effective regimen in relapsed/refractory acute leukemias. The toxicity is acceptable, enabling most patients to receive further treatment, including transplantation procedures.

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.

The prevalent predicament of relapsed acute myeloid leukemia

A majority of patients with acute myeloid leukemia (AML) will relapse after achieving complete remission. At relapse, patients should be risk stratified and a decision made about the appropriateness of intensive therapy and whether a potentially curative allogeneic stem cell transplantation (allo-SCT) is possible. Risk factors include duration of first complete remission and adverse cytogenetics, as well as age and FLT3 mutation status. Available therapies are steadily increasing, but for the most part should be regarded as either best palliation or as a bridge to allo-SCT. Simple symptomatic therapies for patients with extreme age or the worst prognosis should also be considered. Newer therapeutic options include novel cytotoxic chemotherapies including clofarabine, immunomodulatory agents, targeted therapies against FLT3 and mTOR, and immunoconjugates. All patients with relapsed AML should be considered for an appropriate clinical trial.