Diversifying the anthracycline class of anti-cancer drugs identifies aclarubicin for superior survival of acute myeloid leukemia patients.

The efficacy of anthracycline-based chemotherapeutics, which include doxorubicin and its structural relatives daunorubicin and idarubicin, remains almost unmatched in oncology, despite a side effect profile including cumulative dose-dependent cardiotoxicity, therapy-related malignancies and infertility. Detoxifying anthracyclines while preserving their anti-neoplastic effects is arguably a major unmet need in modern oncology, as cardiovascular complications that limit anti-cancer treatment are a leading cause of morbidity and mortality among the 17 million cancer survivors in the U.S. In this study, we examined different clinically relevant anthracycline drugs for a series of features including mode of action (chromatin and DNA damage), bio-distribution, anti-tumor efficacy and cardiotoxicity in pre-clinical models and patients. The different anthracycline drugs have surprisingly individual efficacy and toxicity profiles. In particular, aclarubicin stands out in pre-clinical models and clinical studies, as it potently kills cancer cells, lacks cardiotoxicity, and can be safely administered even after the maximum cumulative dose of either doxorubicin or idarubicin has been reached. Retrospective analysis of aclarubicin used as second-line treatment for relapsed/refractory AML patients showed survival effects similar to its use in first line, leading to a notable 23% increase in 5-year overall survival compared to other intensive chemotherapies. Considering individual anthracyclines as distinct entities unveils new treatment options, such as the identification of aclarubicin, which significantly improves the survival outcomes of AML patients while mitigating the treatment-limiting side-effects. Building upon these findings, an international multicenter Phase III prospective study is prepared, to integrate aclarubicin into the treatment of relapsed/refractory AML patients.

Gilteritinib combined with venetoclax and azacitidine for relapsed acute myeloid leukemia cocurrent with pure red cell aplasia after allogeneic hematopoietic stem cell transplantation: a case report.

Pure red cell aplasia (PRCA) is a rare bone marrow (BM) disorder characterized by ineffective erythropoiesis, reduced reticulocyte count, normocytic anemia, and the absence of erythroid precursors. Here, we present a rare instance of PRCA occurring after ABO-matched allo-HSCT in a refractory/relapsed acute myeloid leukemia (R/R AML) patient. In this case, the patient received a combination treatment of Gilteritinib, Venetoclax, and Azacitidine. Remarkably, this treatment not only reduced myeloblasts but also facilitated the restoration of erythroid hematopoiesis.

CLAG combined with total body irradiation as intensive conditioning chemotherapy prior to allogeneic hematopoietic stem cell transplantation in patients with refractory or relapsed acute myeloid leukemia.

Refractory or relapsed acute myeloid leukemia (R/R AML) remains the major challenge of AML treatment. Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is the only valid option to achieve cure, but the prognosis is still dismal. We conducted a retrospective analysis for the feasibility of CLAG regimens (cladribine, cytarabine, and granulocyte colony-stimulating factor) combined with total body irradiation (TBI) as new intensive conditioning chemotherapy prior to HSCT in R/R AML. A total of 70 patients, including 21 primary refractory and 49 relapsed AML, were analyzed. Forty-nine (70%) patients had extramedullary diseases, and 54 (77%) patients received haploidentical transplantation. Except for one who died before white blood cell engraftment, all of the 69 evaluable patients achieved measurable residual disease (MRD) negative complete remission. The 3-year overall survival (OS) and relapse-free survival (RFS) rates were 46.0% (95% confidence interval [CI], 33.5-57.7%) and 38.5% (95%CI, 26.8-50.0%). The 1-year cumulative incidences of relapse and non-relapse mortality (NRM) were 38.6% (95%CI, 27.3-49.3%) and 11.6% (95%CI: 5.4-20.3%), respectively. The presence of chronic graft-versus-host disease (cGVHD) showed a trend to be associated with a lower risk of relapse (P = 0.054) and extramedullary diseases with a higher risk of NRM (P = 0.074). Multivariate analyses identified low leukemia burden pre-HSCT (defined as bone marrow blasts ≤ 50%) and cGVHD as independent factors associated with favorable OS and RFS. In conclusion, intensive conditioning with CLAG regimens plus TBI may be an effective and well-tolerated choice for R/R AML patients undergoing allo-HSCT.

Venetoclax plus azacitidine and donor lymphocyte infusion in treating acute myeloid leukemia patients who relapse after allogeneic hematopoietic stem cell transplantation.

This study aimed to evaluate the efficacy and safety of venetoclax plus azacitidine and donor lymphocyte infusion (DLI) in treating patients with relapsed acute myeloid leukemia (AML) after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Twenty-six AML patients who relapsed after allo-HSCT were enrolled and treated with venetoclax plus azacitidine and DLI. Complete remission with incomplete recovery (CRi), partial remission (PR), and objective remission rate (ORR) were assessed, and then event-free survival (EFS) and overall survival (OS) were evaluated. Besides, adverse events were documented. Additionally, whole exome sequencing was performed in bone marrow samples. The CRi, PR, and ORR rates were 26.9%, 34.6%, and 61.5%, respectively. The median time of EFS and OS was 120 (95% CI: 71-610) days and 284.5 (95% CI: 81-610) days, respectively. The most common adverse events were hematologic system adverse events including agranulocytosis, anemia, and thrombocytopenia, while the adverse events of other systems were relatively less and milder. In addition, no serious adverse events existed. Of note, there were 6 (23.1%) patients who developed GVHD. As for gene mutation, 49 mutated genes were found, which were categorized as first-, second-, and third-class mutations, and then further analysis revealed that the first-class mutations were not correlated with EFS or OS. Additionally, the most frequent mutated genes were FLT3, CEBPA, DNMT3A, KIT, KRAS, and NRAS. Venetoclax plus azacitidine and DLI is efficient and tolerant in treating patients with relapsed AML after allo-HSCT, implying this combined therapy as a potential treatment option in the studied patients.

Allogeneic hematopoietic stem cell transplantation improves long-term outcome for relapsed AML patients across all ages: results from two East German Study Group Hematology and Oncology (OSHO) trials.

Relapse of acute leukemia is a frequent complication with uncertain outcome and poorly defined risk factors. From 1621 patients entered into two prospective clinical trials (AML02; n = 740 and AML04; n = 881), 74.2% reached complete remission (CR) 1 after induction(s) and 59 patients after additional induction ± hematopoietic cell transplantation (HCT). Of the non-refractory patients, 48.4% with a median age of 63 (range 17-85) years relapsed. Relapses occurred within 6 months after CR in 46.5%, between 7 and 18 months in 38.7%, and after 18 months in 14.8% of patients. Relapse treatment resulted in CR2 in 39% of patients depending upon age (54.5% of ≤ 60 and 28.6% of > 60 years), duration of CR1, and treatment of relapse. Overall survival (OS) was 10.9 (7.4-16.2) %, but OS after HCT ± intensive chemotherapy (ICT) was 39.3% (31.8-48.6) at 5 years and not different in younger and older patients. Donor lymphocyte infusion ± chemotherapy and ICT alone resulted only in OS of 15.4% and of 5%, respectively. Independent favorable factors for OS were long CR1 duration, and HCT, while non-monosomal disease was beneficial for OS in elderly patients. Leukemia-free survival [LFS; 24.9 (19.5-31.7) % at 10 years] was affected by similar risk factors. In a competing risk model, the relapse incidence at 5 years was 53.5 ± 3.5% and the non-relapse mortality rate 21.7 ± 2.9%. Lower relapse incidence was observed in patents with HCT, long CR1 duration, and female gender. Risk factors for non-relapse mortality were HCT in younger and type of AML in elderly patients. In conclusion, allogeneic HCT ± IC improved the results in relapsed AML in younger and elderly patients. Increasing CR2 rates and HCT frequency will be the challenge for the next years. Relapse of the disease remains the major problem.

MRD abnormal expression predict poor outcomes for refractory or relapsed acute myeloid leukemia after allogeneic hematopoietic stem cell transplantation.

We retrospectively analyzed data from 197 patients with refractory or relapsed acute myeloid leukemia (r/rAML) who underwent allo-HCT between January 2013 and February 2020 in our center (patients with promyelocytic leukemia were excluded). Of all patients, 86 achieved a complete morphological remission (CR) before transplant, while 111 failed to do so (NR). In the CR group, 32 patients displayed minimal residual disease (MRD-positive). According to their immunophenotype pre-HCT, we divided the MRD-positive group and NR group into three subgroups: MRD 0+ group (without any antigen abnormal expression of CD7+, CD56+, CD38-, or HLA-DR-) 28 patients, MRD 1+ group (with one abnormal antigen expression of CD7+, CD56+, CD38-, or HLA-DR-) 63 patients, MRD 2+ group (with two or more abnormal antigens expression of CD7+, CD56+, CD38-, or HLA-DR-) 52 patients. 3-year estimates of disease-free survival (DFS) for MRD 0+, MRD 1+ and MRD 2+ patients were 59.5 ± 9.5%, 29.9 ± 6.1%, and 9.4 ± 5.1%, and 3-year estimates of overall survival (OS) were 59.5 ± 9.5%, 34.5 ± 6.3%, and 14.5 ± 10.8%, respectively. Multivariate analysis adjusted for genetic risk, blast cell level, secondary disease, age, sex, and donor relationship pre-HCT, the hazard ratios of abnormal expression of CD7+, CD56+, HLA-DR-, and CD38- were 6.69 (range 2.08-21.52; p = 0.001) for DFS, 2.24 (range 1.21-4.14; p = 0.010) for OS, and 7.18 (range 2.23-23.10; p = 0.001) for relapse compared with CD7-, CD56-, HLA-DR+, and CD38+ patients. Our finding suggested that abnormal expression of CD7+, CD56+, HLA-DR-, and CD38- is associated with poor outcomes, and the more number of abnormal antigens expression predict worse outcomes.

Analysis of Efficacy and Prognostic Factors of CLAG Treatment in Chinese Patients with Refractory or Relapsed Acute Myeloid Leukemia.

BACKGROUND/AIMS: The aim of this work was to investigate the efficacy and predictive factors of CLAG treatment in refractory or relapsed (R/R) acute myeloid leukemia (AML) patients. METHODS: Sixty-seven R/R AML patients were enrolled in this prospective cohort study and treated by a CLAG regimen: 5 mg/m2/day cladribine (days 1-5), 2 g/m2/day cytarabine (days 1-5), and 300 µg/day filgrastim (days 0-5). The median follow-up duration was 10 months. RESULTS: A total of 57 out of 67 patients were evaluable for remission after CLAG therapy, of whom 57.9% achieved a complete remission (CR) and the overall remission rate was 77.2%. The median overall survival (OS) was 10.0 months, with a 1-year OS of 40.3 ± 6.0% and 3-year OS of 16.7 ± 5.7%. CR at first induction after the initial diagnosis was associated with a favorable CR. Age above 60 years, high risk stratification, second or higher salvage therapy, and bone marrow (BM) blasts ≥42.1% were correlated with an unfavorable CR. Secondary disease, age ≥60 years, high risk stratification, and second or higher salvage therapy were associated with worse OS. Patients developed thrombocytopenia (41, 61%), febrile neutropenia (37, 55%), leukopenia (33, 49%), neutropenia (18, 27%), and anemia (9, 13%). CONCLUSION: CLAG was effective and well tolerated for R/R AML. BM blasts ≥42.1%, age ≥60 years, high risk stratification, and second or higher salvage therapy were independent factors for a poor prognosis.

[Clinical outcome of allogeneic hematopoietic stem cell transplantation with FLAG sequential busulfan/cyclophosphamide conditioning regimen for refractory/relapsed acute myeloid leukemia].

Objective: To investigate the therapeutic effects of allogeneic hematopoietic stem cell transplantation (allo-HSCT) with FLAG sequential busulfan/cyclophosphamide(Bu/Cy) conditioning regimen for refractory/relapsed acute myeloid leukemia. Methods: From February 2012 to June 2017, 21 patients with refractory/relapsed acute myeloid leukemia underwent allo-HSCT with FLAG sequential Bu/Cy conditioning regimen. Transplantation-related complications and clinical outcome were retrospectively analyzed. Results: After conditioning, no hepatic veno-occlusive disease (VOD) and grade Ⅲ hemorrhagic cystitis occurred. 76.2% (16/21) patients had fever with 4 septicemia. One patient died of septic shock before engraftment. Twenty patients achieved neutrophil engraftment with a median time of 13 days (range, 10 to 21 days). Seventeen patients achieved platelet engraftment with a median time of 18 days (range, 9 to 25 days). The cumulative incidence of acute graft-versus-host disease (aGVHD) was 39.5%, and 3 patients developed grade Ⅲ-Ⅳ aGVHD. Of 19 patients who survived more than 100 days after transplantation, 4 had local chronic graft-versus-host disease (cGVHD). Of 21 patients, the median survival time was 15 months (range, 0.5 to 67 months) post-transplantation. Transplantation-related mortality rate was 28.7%. Leukemia relapse occurred in 4 patients with a median time of 4 months (range, 3 to 8 months) after transplantation. The cumulative relapse rate at 1 year was 21.4%. The 1-year and 3-year overall survival (OS) rates were 60.7% and 54.9% respectively. Log-rank analysis revealed that bone marrow blasts ≥ 20% or extramedullary leukemia before transplantation, poor platelet engraftment and grade Ⅲ-Ⅳ aGVHD were significantly related to shortened OS (P<0.05). Conclusions: Allo-HSCT with FLAG sequential Bu/Cy conditioning regimen in patients with refractory/relapsed myeloid leukemia has acceptable transplantation-related risk and relapse rate. The 1-year and 3-year OS rates are comparable with those in remission patients.

Increased expression of CD70 in relapsed acute myeloid leukemia after hypomethylating agents.

Acute myeloid leukemia (AML) is the most common acute leukemia in adults. While induction chemotherapy leads to remission in most patients, a significant number will experience relapse. Therefore, there is a need for novel therapies that can improve remission rates in patients with relapsed and refractory AML. CD70 is the natural ligand for CD27 (a member of the TNF superfamily) and appears to be a promising therapeutic target. Consequently, there is considerable interest in developing chimeric antigen receptor (CAR) T-cell therapy products that can specifically target CD70 in various neoplasms, including AML. In this study, we employed routine diagnostic techniques, such as immunohistochemistry and flow cytometry, to investigate the expression of CD70 in bone marrow samples from treatment-naïve and relapsed AML patients after hypomethylating agents (HMA). Also, we evaluated the impact of HMA on CD70 expression and examined CD70 expression in various leukemic cell subsets and normal hematopoietic progenitors.

Gilteritinib: The Story of a Proceeding Success into Hard-to-Treat FLT3-Mutated AML Patients.

The traditionally dismal outcome of acute myeloid leukemia (AML) patients carrying the FMS-related tyrosine kinase 3 (FLT3) mutations has been mitigated by the recent introduction of tyrosine kinase inhibitors (TKI) into clinics, such as midostaurin and gilteritinib. The present work summarizes the clinical data that led to the use of gilteritinib in clinical practice. Gilteritinib is a second-generation TKI with deeper single-agent activity than first-generation drugs against both FLT3-ITD and TKD mutations in human studies. Moreover, the phase I/II dose-escalation, dose-expansion Chrysalis trial showed an acceptable safety profile of gilteritinib (diarrhea, elevated aspartate aminotransferase, febrile neutropenia, anemia, thrombocytopenia, sepsis, and pneumonia) and a 49% overall response rate (ORR) in 191 FLT3-mutated relapsed/refractory (R/R) AML patients. In 2019, the pivotal ADMIRAL trial showed that the median overall survival was significantly longer in patients treated with gilteritinib than among those receiving chemotherapy (9.3 vs. 5.6 months, respectively) and the ORR to gilteritinib was 67.6%, outperforming the 25.8% for chemotherapy arm and leading to the license for its clinical use by the US Food and Drug Administration. Since then, several real-world experiences have confirmed the positive results in the R/R AML setting. Finally, gilteritinib-based combinations currently under investigation, with several compounds (venetoclax, azacitidine, conventional chemotherapy, etc.) and some practical tips (maintenance after allogeneic transplantation, interaction with antifungal drugs, extramedullary disease, and onset of resistance), will be analyzed in detail in this review.

Combination of Venetoclax and Midostaurin Efficiently Suppressed Relapsed t(8;21)Acute Myeloid Leukemia With Mutant KIT After Failure of Venetoclax Plus Azacitidine Treatment.

Acute myeloid leukemia (AML) with t(8;21) is categorized as favorable-risk AML, but KIT mutations show a significantly poor prognostic impact in such patients. Persistent vulnerability to relapse is a major challenge in the treatment of this subtype of patients. Venetoclax is a BCL-2 selective inhibitor. The venetoclax+HMA strategy is also a notable salvage regimen that achieves good clinical outcomes in the treatment of relapsed or refractory (R/R) AML. However, in our clinical practice, we found that disease progressed rapidly even after venetoclax+azacitidine (AZA) therapy in two relapsed t(8;21) AML patients with KIT mutations. We report for the first time the therapeutic potential of venetoclax+midostaurin as a new combination therapy for relapsed t(8;21) AMLs with KIT mutations showing resistance to venetoclax+AZA therapy. Our ex vivo study also showed that midostaurin alone could inhibit proliferation and induce apoptosis of Kasumi-1 cells (e.g. Midostaurin induced G2 phase cell arrest, down-regulated p-KIT and BCL-2, while Bax protein levels were up-regulated) and observed a synergistic anti effect when the two drugs were combined. Our study shows that the venetoclax+midostaurin regimen may be a promising treatment option for R/R t(8;21) AML with KIT mutations.

Successful combination chemotherapy involving clofarabine, cyclophosphamide, and etoposide for pediatric relapsed acute myeloid leukemia: A case report.

Limited salvage chemotherapies are available for relapsed/refractory acute myeloid leukemia. Herein, we described successful reinduction chemotherapy, involving a combination of clofarabine, cyclophosphamide, and etoposide, in a 12-year-old male with relapsed acute myeloid leukemia prior to allogeneic bone marrow transplantation from his father. Although treatment with a combination of fludarabine, cytarabine, granulocyte colony-stimulating factor, idarubicin, and gemtuzumab ozogamicin had no positive effects, the aforementioned clofarabine-based chemotherapy induced complete remission and allowed the transplantation to go ahead. The abovementioned regimen may be useful for induction chemotherapy prior to hematopoietic stem cell transplantation for refractory/relapsed acute myeloid leukemia.

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.

CD38-directed CAR-T cell therapy: a novel immunotherapy strategy for relapsed acute myeloid leukemia after allogeneic hematopoietic stem cell transplantation.

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a potentially curative treatment for acute myeloid leukemia (AML). However, most patients experience relapse after allo-HSCT, with a poor prognosis, and treatment options are limited. The lack of an ideal targetable antigen is a major obstacle for treating patients with relapsed AML. CD38 is known to be expressed on most AML and myeloma cells, and its lack of expression on hematopoietic stem cells (HSCs) renders it a potential therapeutic target for relapsed AML. To investigate the clinical therapeutic efficacy and safety of CD38-targeted chimeric antigen receptor T (CAR-T-38) cells, we enrolled 6 AML patients who experienced relapse post-allo-HSCT (clinicaltrials.gov: NCT04351022). Prior to CAR-T-38 treatment, the blasts in the bone marrow of these patients exhibited a median of 95% (92-99%) CD38 positivity. Four weeks after the initial infusion of CAR-T-38 cells, four of six (66.7%) patients achieved complete remission (CR) or CR with incomplete count recovery (CRi); the median CR or CRi time was 191 (range 117-261) days. The cumulative relapse rate at 6 months was 50%. The median overall survival (OS) and leukemia-free survival (LFS) times were 7.9 and 6.4 months, respectively. One case relapsed 117 days after the first CAR-T-38 cell infusion, with remission achieved after the second CAR-T-38 cell infusion. All six patients experienced clinically manageable side effects. In addition, multiparameter flow cytometry (FCM) revealed that CAR-T-38 cells eliminated CD38 positive blasts without off-target effects on monocytes and lymphocytes. Although this prospective study has a limited number of cases and a relatively short follow-up time, our preliminary data highlight the clinical utility and safety of CAR-T-38 cell therapy in treating relapsed AML post-allo-HSCT.

Chidamide increases the sensitivity of refractory or relapsed acute myeloid leukemia cells to anthracyclines via regulation of the HDAC3 -AKT-P21-CDK2 signaling pathway.

BACKGROUND: Induction therapy for acute myeloid leukemia (AML) is an anthracycline-based chemotherapy regimen. However, many patients experience a relapse or exhibit refractory disease (R/R). There is an urgent need for more effective regimens to reverse anthracycline resistance in these patients. METHODS: In this paper, Twenty-seven R/R AML patients with anthracycline resistance consecutively received chidamide in combination with anthracycline-based regimen as salvage therapy at the Chinese PLA General Hospital. RESULTS: Of the 27 patients who had received one course of salvage therapy, 13 achieved a complete response and 1 achieved a partial response. We found that the HDAC3-AKT-P21-CDK2 signaling pathway was significantly upregulated in anthracycline-resistant AML cells compared to non-resistant cells. AML patients with higher levels of HDAC3 had lower event-free survival (EFS) and overall survival (OS) rates. Moreover, anthracycline-resistant AML cells are susceptible to chidamide, a histone deacetylase inhibitor which can inhibit cell proliferation, increase cell apoptosis and induce cell-cycle arrest in a time- and dose-dependent manner. Chidamide increases the sensitivity of anthracycline-resistant cells to anthracycline drugs, and these effects are associated with the inhibition of the HDAC3-AKT-P21-CDK2 signaling pathway. CONCLUSION: Chidamide can increase anthracycline drug sensitivity by inhibiting HDAC3-AKT-P21-CDK2 signaling pathway, thus demonstrating the potential for application.

Long non-coding RNA taurine-upregulated gene 1 correlates with unfavorable prognosis in patients with refractory or relapsed acute myeloid leukemia treated by purine analogue based chemotherapy regimens.

OBJECTIVE: This study aimed to explore the correlation of long non-coding RNA taurine-upregulated gene 1 (lncRNA TUG1) expression with clinicopathological features and its predictive value for treatment response and survival profiles in refractory or relapsed acute myeloid leukemia (R/R AML) patients. METHODS: Seventy three R/R AML patients who received cladribine combined with cytarabine and granulocyte colony-stimulating factor (G-CSF) (CLAG) or fludarabine combined with cytarabine and G-CSF (FLAG) based chemotherapy and 37 non-malignant controls were recruited. LncRNA TUG1 expression was detected in bone marrow sample obtained before treatment. Complete response (CR), partial response (PR), overall response rate (ORR) and overall survival (OS) were evaluated. RESULTS: LncRNA TUG1 expression was upregulated in R/R AML patients compared to controls. It was also elevated in R/R AML patients with age ⩾ 60 years (vs. age < 60 years, P= 0.030) and in patients with secondary AML (vs. primary AML, P= 0.035). R/R AML patients with lncRNA TUG1 high expression achieved numerically lower CR (P= 0.053), decreased ORR (P= 0.028) and shorter OS (P< 0.001) than patients with lncRNA TUG1 low expression. Univariate logistic regression and COX's regression disclosed that lncRNA TUG1 high expression correlated with declined ORR, numerically decreased CR, and reduced OS. Furthermore, multivariate analyses verified that lncRNA TUG1 high expression was an independent predictive factor for decreased ORR and worse OS. CONCLUSIONS: In conclusion, lncRNA TUG1 expression was elevated in R/R AML patients, and it might serve as a potential biomarker for poor prognosis in R/R AML patients treated with CLAG or FLAG based chemotherapy.

Comparison of clinical remission and survival between CLAG and FLAG induction chemotherapy in patients with refractory or relapsed acute myeloid leukemia: a prospective cohort study.

PURPOSE: To compare the clinical remission and survival between CLAG and FLAG induction chemotherapy in treating patients with refractory or relapsed acute myeloid leukemia (R/R AML). METHODS: 103 R/R AML patients were consecutively enrolled in this prospective cohort study. 55 patients were treated by CLAG induction chemotherapy as follows: 5 mg/m2/day cladribine (days 1-5); 2 g/m2/day cytarabine (days 1-5) and 300 µg/day filgrastim (days 0-5). While 48 patients were treated by FLAG: 30 mg/m2/day fludarabine (days 1-5), 2 g/m2/day cytarabine (days 1-5), and 300 µg/day filgrastim (days 0-5). RESULTS: CLAG induction chemotherapy achieved 61.7% complete remission rate (CR) and 78.7% overall remission rate (ORR), which was similar with FLAG chemotherapy which realized 48.7% CR and 69.2% ORR. No difference of overall survival (OS) was discovered between two groups either. Age cytarabine 60 years, secondary disease, poor risk stratification and BM blast ≥ 42.7% and second or higher salvage therapy were independent factors for worse prognosis. Subgroups analysis revealed that in patients with second or higher salvage therapy, CLAG seemed to achieve a higher CR than FLAG. And in patients with relapsed disease, poor risk stratification or CR at first induction, CLAG seemed to realize a prolonged OS compared to FLAG. CONCLUSION: CLAG was equally effective to FLAG induction chemotherapy in total R/R AML patients, while CLAG seemed to be a better option than FLAG in patients with relapsed disease, poor risk stratification, CR at first induction or second or higher salvage therapies.

Disulfiram overcomes bortezomib and cytarabine resistance in Down-syndrome-associated acute myeloid leukemia cells.

BACKGROUND: Children with Down syndrome (DS) have increased risk for developing AML (DS-AMKL), and they usually experience severe therapy-related toxicities compared to non DS-AMKL. Refractory/relapsed disease has very poor outcome, and patients would benefit from novel, less toxic, therapeutic strategies that overcome resistance. Relapse/resistance are linked to cancer stem cells with high aldehyde dehydrogenase (ALDH) activity. The purpose of the present work was to study less toxic alternative therapeutic agents for relapsed/refractory DS-AMKL. METHODS: Fourteen AML cell lines including the DS-AMKL CMY and CMK from relapsed/refractory AML were used. Cytarabine (Ara-C), bortezomib (BTZ), disulfiram/copper (DSF/Cu2+) were evaluated for cytotoxicity, depletion of ALDH-positive cells, and resistance. BTZ-resistant CMY and CMK variants were generated by continuous BTZ treatment. Cell viability was assessed using CellTiter-Glo®, ALDH activity by ALDELUORTM, and proteasome inhibition by western blot of ubiquitinated proteins and the Proteasome-Glo™ Chymotrypsin-Like (CT-like) assay, apoptosis by Annexin V Fluos/Propidium iodide staining, and mutations were detected using PCR, cloning and sequencing. RESULTS: Ara-C-resistant AML cell lines were sensitive to BTZ and DSF/Cu2+. The Ara-C-resistant DS-AMKL CMY cells had a high percentage of ALDHbright "stem-like" populations that may underlie Ara-C resistance. One percent of these cells were still resistant to BTZ but sensitive to DSF/Cu2+. To understand the mechanism of BTZ resistance, BTZ resistant (CMY-BR) and (CMK-BR) were generated. A novel mutation PSMB5 Q62P underlied BTZ resistance, and was associated with an overexpression of the ß5 proteasome subunit. BTZ-resistance conferred increased resistance to Ara-C due to G1 arrest in the CMY-BR cells, which protected the cells from S-phase damage by Ara-C. CMY-BR and CMK-BR cells were cross-resistant to CFZ and MG-132 but sensitive to DSF/Cu2+. In this setting, DSF/Cu2+ induced apoptosis and proteasome inhibition independent of CT-like activity inhibition. CONCLUSIONS: We provide evidence that DSF/Cu2+ overcomes Ara-C and BTZ resistance in cell lines from DS-AMKL patients. A novel mutation underlying BTZ resistance was detected that may identify BTZ-resistant patients, who may not benefit from treatment with CFZ or Ara-C, but may be responsive to DSF/Cu2+. Our findings support the clinical development of DSF/Cu2+ as a less toxic efficacious treatment approach in patients with relapsed/refractory DS-AMKL.

Cerebral embolism through hematogenous dissemination of pulmonary mucormycosis complicating relapsed leukemia.

Invasive mucormycosis in patients with hematological diseases mostly occurs in the lungs. Invasive mucormycosis of other anatomical sites is relatively infrequent and its pathogenesis has not so far been well elucidated. Here, we describe an autopsy case of pulmonary invasive mucormycosis complicated by cerebral embolism with infarct. A 77-year-old Japanese woman with relapsed acute myeloid leukemia complained of left visual disturbance and weakness of the lower limbs. The diagnosis of leukemic infiltration to the central nervous system was made. Repeated intrathecal injection of methotrexate plus cytarabine resulted in partial amelioration of the neurologic symptoms. However, the patient then developed fever, dyspnea, and subsequent right hemiparesis. A computed tomography (CT) scan showed a consolidative shadow with halo sign in the left lung field, which was compatible with either invasive pulmonary aspergillosis or mucormycosis. These findings accounted for fever and dyspnea, but not hemiparesis. Despite antifungal therapy, the patient succumbed to death after two weeks. Autopsy revealed pulmonary invasive mucormycosis with a fungal ball in the lumina of the adjacent ascending aorta. Intriguingly, autopsy and postmortem CT scan identified left cerebral infarct due to mucormycosis, which accounted for the right hemiparesis. It is likely that the fungal ball caused the cerebral embolism through hematogenous dissemination. We should suspect hematogenous dissemination when we see a patient with pulmonary invasive mucormycosis developing neurologic symptoms.