Acute Myeloid Leukemia Regimens Research Articles

Impact of antithymocyte globulin on outcomes of allogeneic hematopoietic cell transplantation with TBI

AbstractThe impact of the use of antithymocyte globulin (ATG) following a total body irradiation (TBI)–based myeloablative conditioning regimen has been poorly explored. We retrospectively analyzed 724 patients who underwent a first allogeneic hematopoietic cell transplantation (allo-HCT) following a TBI-based conditioning regimen for acute myeloid leukemia (AML) and compared the outcomes of 251 (35%) patients who received ATG (ATG group) with 473 (65%) patients who did not (non-ATG group). Median follow-up of surviving patients was 59 months (interquartile range, 28-83). The cumulative incidence of grade II-IV acute graft-versus-host disease (aGVHD) for non-ATG and ATG groups in the first 100 days was 33% vs 24%, respectively (P = .0098). The 2-year cumulative incidence of chronic graft-versus-host disease (cGVHD) was reduced significantly in the ATG group in comparison with the non-ATG group (46% vs 34%, P = .003). Using multivariate analysis, in vivo T-cell depletion (ATG group) was independently associated with a decreased incidence of grade II-IV aGVHD (hazard ratio [HR], 0.28; P < .001), grade III-IV aGVHD (HR, 0.21; P < .001), cGVHD (HR, 0.63; P = .02), and nonrelapse mortality (NRM) (HR, 0.54; P = .02). Relapse risk, overall survival, and leukemia-free survival were similar between the 2 groups. Our results suggest that the addition of ATG to TBI-based myeloablative conditioning for allo-HCT in AML patients results in a significant reduction in aGVHD and cGVHD, translating into a significant reduction in NRM without increasing the relapse rate.

Timed sequential therapy with high-dose cytarabine and mitoxantrone as an induction regimen for acute myeloid leukemia: An update on adverse events.

e18524 Background: Traditionally, patients eligible for induction chemotherapy for AML are treated with the “7+3” regimen, standard doses of infusional cytarabine and an anthracycline, with historical CR rates of 50-60%. We present a retrospective analysis of an alternate induction regimen. Based on timed sequential therapy, it consists of a 2-day treatment with high dose cytarabine, which improves remission rates when used in induction, and dose intensified anthracycline therapy, which improves outcomes while maintaining an acceptable safety profile. Methods: 200 patients were treated from 2010-2015. Patients received 2 doses of cytarabine 2 gm/m2 (1.5 gm/m2 age &gt; 70 years) IVPB over 3 hours, 12 hours apart followed by 1 dose of mitoxantrone 30 mg/m2 IVPB over 1 hour on days 1 and 5. Cytogenetics and adverse events data were collected. IWG remission criteria were used to determine remission status. Results: Median age 57.6 years (range 23-79); 105 (53%) age &gt; 60. 119 male; 81 female. Risk stratification: 12 favorable; 108 intermediate; 80 unfavorable . Overall CR rate (CRR: CR+CRi+CRp) for all patients was 68.5%. CR rates based on risk karyotypes: favorable 100%, intermediate 76.8%, unfavorable 52.5%. Most common G3-4 adverse events: anemia (60% G3, 40% G4), neutropenia (1% G3, 99% G4), thrombocytopenia (0.5% G1, 99.5% G4). 196 patients (98%) had neutropenic fever; 134 (67%) documented infections (100 with G3/4), 62 (31%) neutropenic fever with no source. 52 (26%) experienced bleeding (15 G1, 31 G2, 4 G3, 1 G4, 1 G5). G3/4 renal or hepatic toxicity was rare. No cerebellar toxicity occurred during induction. 30 day mortality 0.5%; 60 day mortality 3%. 62 (31%) patients are still alive; 122 died, 16 lost to follow-up. Conclusions: This two-day induction regimen is an effective treatment for AML with an acceptable safety profile including patients age &gt;60. There is a high response rate, particularly for favorable and intermediate risk karyotypes, with a low rate of early mortality. The high response rates and tolerability with this regimen provides a platform for further clinical trials to enhance outcome by combining with novel targeted therapies for AML.

8-chloro-adenosine activity in FLT3-ITD acute myeloid leukemia.

Nucleoside analogs represent the backbone of several distinct chemotherapy regimens for acute myeloid leukemia (AML) and combination with tyrosine kinase inhibitors has improved survival of AML patients, including those harboring the poor-risk FLT3-ITD mutation. Although these compounds are effective in killing proliferating blasts, they lack activity against quiescent leukemia stem cells (LSCs), which contributes to initial treatment refractoriness or subsequent disease relapse. The reagent 8-chloro-adenosine (8-Cl-Ado) is a ribose-containing, RNA-directed nucleoside analog that is incorporated into newly transcribed RNA rather than in DNA, causing inhibition of RNA transcription. In this report, we demonstrate antileukemic activities of 8-Cl-Ado in vitro and in vivo and provide mechanistic insight into the mode of action of 8-Cl-Ado in AML. 8-Cl-Ado markedly induced apoptosis in LSC, with negligible effects on normal stem cells. 8-Cl-Ado was particularly effective against AML cell lines and primary AML blast cells harboring the FLT3-ITD mutation. FLT3-ITD is associated with high expression of miR-155. Furthermore, we demonstrate that 8-Cl-Ado inhibits miR-155 expression levels accompanied by induction of DNA-damage and suppression of cell proliferation, through regulation of miR-155/ErbB3 binding protein 1(Ebp1)/p53/PCNA signaling. Finally, we determined that combined treatment of NSG mice engrafted with FLT3-ITD + MV4-11 AML cells with 8-Cl-Ado and the FLT3 inhibitor AC220 (quizartinib) synergistically enhanced survival, compared with that of mice treated with the individual drugs, suggesting a potentially effective approach for FLT3-ITD AML patients.

Participation of vitamin D-upregulated protein 1 (TXNIP)-ASK1-JNK1 signalosome in the enhancement of AML cell death by a post-cytotoxic differentiation regimen

Standard therapy for Acute Myeloid Leukemia (AML) is rarely curative, and several suggested improvements have had little success so far. We have reported that in an in vitro model of a potential therapeutic regimen for AML, the activity of cytarabine (AraC) is enhanced by a sequential treatment with a combination of the vitamin D2 analog Doxercalciferol (D2) and the plant-derived antioxidant carnosic acid (CA). Importantly, the enhancement occurred selectively in patient-derived AML blasts, but not in the normal bone marrow cells. We now demonstrate that TXNIP, previously known as Vitamin D up-regulated protein 1 (VDUP1) [PMID 808674] plays a part in signaling cell death (CD) in this regimen. This is shown by the reduced CD when TXNIP protein levels are decreased by the CRISPR/CAS9 or RNAi technology. Further, we show that direct activation of ASK1 kinase by TXNIP is required for the optimal transmission of the CD signal to apoptotic machinery, regulated by JNK and BIM. These studies provide a rationale for a projected clinical trial of this vitamin D-based new therapeutic regimen for AML.

Reduced Intensity Conditioning (RIC) Regimens Hematopoietic Cell Transplantation (HCT) for Acute Myeloid Leukemia (AML): A Comparison of Fludarabine/Busulfan (FB) and Fludarabine/Melphalan (FM) Based Regimens from the CIBMTR

Background: There is limited data comparing the outcomes of the two most common (FM or FB) RIC regimens in AML. Previous smaller retrospective studies suggest increased non-relapse mortality (NRM) but decreased relapse with FM based RIC with a variable effect on overall survival as compared to FB.Methods: AML patients aged ≥18 years who had their 1st allo HCT using FM or FB (iv Bu only) RIC between 2001-2015 who had data reported to CIBMTR were studied. Patients with cord blood or identical twin donors, TBI as a part of conditioning, GVHD prophylaxis with T cell depletion/CD34 selection or post HCT Cyclophosphamide were excluded. Primary endpoint was overall survival (OS), and secondary endpoints included non-relapse mortality (NRM), relapse, leukemia free survival (LFS) and acute and chronic GVHD. Cox proportional hazards multivariable regression was used to compare the two RIC regimens while adjusting for significant patient, disease and transplant related factors. Major subgroup analysis included patients in CR pre-HCT.Results: 622 patients received FB and 791 had FM RIC. Median age of the FM group was 59 years, range (18 to 76) and median age of FB group was 61 years, range (18- 77). Compared to FB RIC regimen, FM group had more patients with active disease (36% vs 18%), with mismatched donors (24% vs 15%), with bone marrow grafts (19% vs 9%), HCT before 2005 (29% vs 12%) and without ATG/alemtuzumab (58 % vs 48%); but fewer patients in CR1 (46% vs 62%) and matched sibling donor grafts (21% vs 30%). There was significantly increased NRM in the FM vs FB within 3 mo post HCT (hazard ratio (HR)=3.85 (95% confidence intervals [CI] 2.46-6.03), but not beyond 3 mo FM vs FB , HR= 1.14 (95% CI 0.88-1.47). There was significantly decreased relapse for FM vs FB, (HR=0.65 (0.55-0.76), p<0.001) and a marginally superior LFS for FM vs FB, (HR=0.89 (95% CI 0.78-1.00), p=0.05). There was a lower OS FM vs FB within 3 mo post HCT (HR=1.82 (95% CI 1.36-2.45), p<0.001) but similar OS for FM vs FB beyond 3 mo post HCT (HR=0.87 (95% CI 0.76-1.00), p=0.05). Analysis restricted to only patients in CR pre-HCT showed similar results: equivalent survival, higher early NRM and lower relapse with FM.Conclusion: The current study of this large CIBMTR AML transplant cohort has showed that in these two most common RIC regimens for allogeneic HCT, long-term survival with FM was similar to FB. While the FM regimen showed higher early NRM, it was associated with lower risks of relapse. Further analysis to evaluate FB and FM regimens in relationship to comorbidities, comprehensive geriatric assessments, and presence of minimal residual disease is warranted to better define the relative efficacy of these two RIC regimens in AML. [Display omitted] DisclosuresWeisdorf:Pharmacyclics: Consultancy; Seattle Genetics: Consultancy; SL Behring: Consultancy; FATE: Consultancy; Equillium: Consultancy.

A Double Priming Induction Regimen for Acute Myeloid Leukemia with Inferior PS Among Resource Limited Areas

The treatment options for patients with acute myeloid leukemia (AML) under inferior performance status (i.e. senior patients, MDS transformed AML, and patients with proven invasive fungal disease) are limited. The conventional “3+7” (idarubicin plus cytarabine) induction for those patients can be either too toxic, which leads to higher mortality rate, or requires prolonged recovery time thus raise medical cost. And the delay of consolidation may compromise outcome thus cause early relapse in such patients.Giving the rationale from the designing art of CPX-351, the prolonged IV time requirement for cytarabine, as well as mini-transplantation for AML treatment, at least in part, reflects the philosophy of a longer exposure to the chemo agent can be a more effective treatment approach for leukemia. On the other hand, the D-CAG protocol, which indicated an encouraging result for elderly patients with AML, indicated effectiveness of the strategy with reduced intensity. However, the cyto-toxic effect of decitabine with standard dose (20mg/m2) could still lead to severe treatment adverse events (AEs) thus raise the need of optimization of D-CAG regimen for patients with inferior PS.When considering the low dose hypo-methylation agent (HMA) can trigger the innate immunity response, the unique effect of homoharringtonine, as well as the effectiveness of CAG, we designed this DHCAG protocol following the principle of “longer exposure, lower intensity preceded by priming” and observed an unexpected excellent outcome with high CR rate, low induction failure and treatment mortality, as well as a higher cost effective value for patients with AML, when compared to “3+7” protocol, whom under inferior PS.From March 2016 - January 2018, we initiated this pilot study and investigated the safety and efficiency of this DHCAG protocol in patients with AML under poor PS. We enrolled 25 patients and administer the regimen as followings: i) G-CSF: 5μg/kg used when WBC <20×10^9/L at day 0-14 subcutaneous injection; ii) Decitabine: 6mg/m2 at day 0, 3, 6, 9, 12 iv drip; iii) Aclarubicin: 6mg/m2 at day 1-8 iv drip; iv) Homoharringtonine: 1mg/m2 at day 9-14 iv drip ( at day 9, if WBC >1*10^9/L then increase the dosage of homoharringtonine to 2mg/m2); iv) Cytarabine:10mg/m2 q12h at day 1-14 subcutaneous injection (if WBC >20*10^9/L then increase to 100mg/m2 by 24h CIV, or 50mg/m2 q12h by subcutaneous injection).The primary end point was complete hematologic remission, defined as a bone marrow blast cells ≤5%, Neutrophils in peripheral blood ≥1.0X109 /L, hemoglobin≥90g/L, and platelets ≥100X109/L and no any evidence of extramedullary leukemic infiltration; Secondary end points included numbers of adverse events, length of hospital stay, medical costs, and quality of life as measured with the use of the Functional Assessment of Cancer Therapy - General (FACT-G) questionnaire. Among the 25 patients in the study, 23 completed the induction therapy. And 21/25 patients had a hematologic complete remission after a median time of 19 days. Once complete remission had occurred, all 21 patients received post-remission treatment for another 5 cycles of DHCAG. Median follow-up was 14 months (range, 8 to 19) by June 2018. Interestingly, regardless of grade 3-4 myelo-suppression occurred all of our patients during induction, eight patients did not experienced grade 3-4 myelo-suppression during the following cycles. The median hospital stay is 22 days. The median of total medical costs for induction was $9,815 (range, $5,053 to $16,336) vs $14,705 for “3+7” induction protocol (history control. Data unpublished). Patients resumed their usual lifestyle during post-remission therapy, and their quality of life was rated as nearly normal on the FACT-G questionnaire. At the time of the last follow-up, seven patients had had a hematologic relapse. The results of our pilot study, in which we tested a priming based, low dose and longer exposure in 25 patients with AML under poor PS, showed that the treatment was safe, effective, and economical. A prospective multicenter, randomized trial comparing DHCAG with IA is now under way in China. DisclosuresNo relevant conflicts of interest to declare.

Comparison of Salvage Chemotherapy Regimens in Relapsed/Refractory Acute Myeloid Leukemia

BackgroundInduction therapy for acute myeloid leukemia (AML) with a cytarabine-anthracycline regimen (7+3) is well-established; however, there is no standard salvage therapy for patients with relapsed/refractory AML (RR-AML). There is a paucity of data regarding outcomes with salvage regimens in RR-AML that include cladribine, cytarabine, and filgrastim with mitoxantrone (CLAG-M) or without mitoxantrone (CLAG), and mitoxantrone, etoposide, and cytarabine (MEC). We compared outcomes of patients receiving CLAG-M, CLAG or MEC as salvage therapy for RR-AML.MethodsA multi-center retrospective study was conducted, including 146 adult RR-AML patients who underwent salvage therapy at the University of Wisconsin and Medical College of Wisconsin from 2009 to 2018. Demographic, clinical and pathologic factors were ascertained at the time of RR-AML diagnosis. The Center for International Blood and Marrow Transplant Research (CIBMTR) response criteria were used. Refractory AML was defined as failure to achieve remission after one or more courses of induction chemotherapy. Minimal residual disease (MRD)-negative was defined by the absence of leukemic cells by morphology and flow cytometry (<0.01%). Data were analyzed using SPSS version 21 (SPSS Inc, Chicago, IL). Bivariate analyses, using chi-square and t-test, and logistic regression analyses were performed for baseline characteristics and response to salvage chemotherapy. Kaplan-Meier analyses, using the log-rank test, were conducted. Cox regression analyses were used to correlate factors with OS. Hazard ratios (HR) with 95% CI were obtained. Statistical significance was considered at P<0.05.ResultsThe study included 146 patients with relapsed (57.5%, n=84) or refractory (42.5%, n=62) AML who received CLAG-M (51%, n=74), MEC (39%, n=57) or CLAG (10%, n=15) salvage chemotherapy. Baseline characteristics were similar between the three groups (all P>0.1). Median age was 60 years (range 22-77 years) and 59% patients were male. AML was classified according to WHO 2016 guidelines as AML with recurrent genetic abnormalities (23%), myelodysplasia (MDS)-related AML (25%), therapy-related AML (8%) and AML not otherwise specified (44%). Cytogenetics were good (5%), intermediate (60%) and poor (36%) with normal (41%), complex (25%), trisomy (8%) and monosomy 5 or 7 (5.5%) being common karyotypes. Among those who had molecular testing (n=119), NPM1 and FLT3-ITD were reported in 21% and 20% patients respectively. AML risk status was good (16%), intermediate (32%) and poor (52%), based on cytogenetic and molecular abnormalities as per ELN 2017 and NCCN 2018 guidelines. Extramedullary disease was present in 13% patients. Prior hematopoietic stem cell transplant (HSCT) was performed in 13% patients. Median lab values prior to salvage regimen were: hemoglobin 9.1 g/dL, platelets 49 K/uL, leukocytes 2.5 K/uL, LDH 231 U/L and bone marrow myeloblasts 28%. Overall response rate was 49% (CLAG-M 55%, n=41/74; MEC 44%, n=25/57, CLAG 40%, n=6/15) with complete remission (CR) rate of 46% (CLAG-M 54%, MEC 37%, CLAG 40%) [P=0.140]. Three percent patients (n=5; CLAG-M=1, MEC=4) had CR with incomplete hematologic recovery (CRi). MRD analysis was available for 83 patients and a trend was seen in MRD-negative CR rates favoring CLAG-M (44%) over MEC (25%) or CLAG (17%) [P=0.128]. Sixty-six patients (45%) received subsequent HSCT (CLAG-M 50%, n=37/74; MEC 44%, 25/57; CLAG 27%, n=4/15) [P=0.245]. At last follow-up, 34% patients were in CR (CLAG-M 42%, MEC 28%, CLAG 20%) [P=0.120]. Fifty (34%) patients were alive at last follow-up (CLAG-M 46%, MEC 23%, CLAG 20%) [P=0.010]. Median OS was 9.7 months (95% CI 6.8-12.6) that was significantly better with CLAG-M (13.3 months, 95% CI 2.4-24.3) compared to MEC (6.9 months, 95% CI 2.9-10.9) or CLAG (6.2 months, 95% CI 2.4-12.6) [P=0.025] Figure 1. In multivariate model adjusted for age, gender and refractory vs relapsed AML, MEC (HR 1.75, 95% CI 1.13-2.71, P=0.013) and CLAG (HR 1.97, 95% CI 1.02-3.79, P=0.043) regimens had worse OS compared to CLAG-M. After adjusting for age, gender, refractory vs relapsed AML and HSCT, CLAG-M remained independent predictor of better OS (HR 0.64, 95% CI 0.42-0.97, P=0.037).ConclusionCLAG-M compared to MEC or CLAG is associated with significantly better OS in RR-AML regardless of age, refractory vs relapsed AML and HSCT. Our findings support the use of CLAG-M as a preferred salvage regimen for RR-AML. [Display omitted] DisclosuresAtallah:Novartis: Consultancy; BMS: Consultancy; Jazz: Consultancy; Abbvie: Consultancy; Pfizer: Consultancy.

Antileukemic Activity of 8-Chloro-Adenosine (8-Cl-Ado) Is Mediated By Mir-155 Degradation and ErbB3 Binding Protein (Ebp1)-Dependent p53 Activation: A Novel Therapeutic Approach for FLT3-ITD Acute Myeloid Leukemia (AML)

AML patients (pts) carrying the fms-related tyrosine kinase 3 (FLT3)-internal tandem duplication (ITD) have a poor prognosis. Combination of chemotherapy with tyrosine kinase inhibitors (TKIs) has improved survival of these pts, but a large proportion of them still die of their disease. Nucleoside analogs (NAs) are the backbone of several upfront and salvage chemotherapy regimens for AML, including FLT3-ITD. Although these agents have significant antileukemic activity, they are not effective in eradicating leukemia stem cells (LSCs), the likely reason for treatment failures in AML. Consequently, new strategies are needed to improve the outcome for this and other molecular subsets of AML pts. 8-Cl-Ado is a novel, ribose-containing, RNA-directed nucleoside analog which, different from other NAs, is incorporated into newly transcribed RNA rather than in DNA, causing inhibition of RNA transcription. Among the AML molecular subsets, we identified FLT3-ITD blasts as one of the most sensitive to 8-Cl-Ado; however the mechanism of this differential effect remains unknown. Ex-vivo treatment with 8-Cl-Ado induced dose-dependent growth inhibition and apoptosis in FLT3-ITD AML cell lines and primary blasts including the LSC-enriched CD34+CD38- immunophenotypic subpopulation, with IC50s ranging from 200 nM to 1400 nM and a negligible effect on normal hematopoietic stem cells. In an orthotopic murine model, mice xenografted with FLT3-ITD-positive MV4-11 cells and treated (upon engraftment) with 75 mg 8-Cl-Ado/kg/day through an implanted osmotic pump survived significantly longer than vehicle-treated controls (median survival 45 days vs. 27.3 days, p=0.002). MicroRNA-155 (miR-155) is the most over-expressed miRNA in FLT3-ITD and reportedly plays a key role in FLT3-ITD blast hyper-proliferation [PMID 20656931, PMID 25971362]. Thus, silencing of miR-155 has been proposed as a novel therapeutic approach for FLT3-ITD AML [PMID 25971362]. As 8-Cl-Ado is incorporated mainly into RNA, we reasoned that it could also be incorporated into miR-155 (and other miRNAs). Consistent with our hypothesis, we detected co-localization of 8-Cl-Ado and miR-155 in FLT3-ITD primary blast cells and MV4-11, using fluorescence-labeled 8-Cl-Ado (8-Cl-Ado-FAM) and miR-155 staining (SmartFlare probes), suggesting that 8-Cl-Ado interacts directly with miR-155. Using quantitative RT-PCR we demonstrated ~50% miR-155 down-regulation in 8-Cl-Ado-FAM or 8-Cl-Ado-treated MV4-11 cells and FLT3-ITD primary blast cells, compared to vehicle-treated controls. On a molecular level, 8-Cl-Ado-dependent miR-155 down-regulation was accompanied by up-regulation of SHIP1, a bona fide miR-155 target phosphatase that decreased p-AKT levels thereby negatively regulating FLT3-ITD-dependent AKT signaling required for leukemia cell growth and survival. This effect also disrupted the interaction of AKT and ErbB3 binding protein (Ebp1), a highly expressed protein that regulates p53 expression and prevents DNA fragmentation and apoptosis in normal and leukemic cells. Thus, we hypothesized by disrupting the AKT/Ebp1 interplay via miR-155 down-regulation, 8-Cl-Ado induces pro-apoptotic Ebp1-dependent p53 expression and activation and leukemia cell death. Indeed, we showed that 8-Cl-Ado treatment caused AKT/Ebp1 dissociation and p53 activation in primary FLT3-ITD AML blasts. Conversely, overexpression of miR-155 reversed 8-Cl-Ado-induced apoptosis. By combining 8-Cl-Ado with the TKI quizartinib we elicited a synergistic anti-leukemic effect in primary AML blasts [combination index (CI) values <1 at doses required to inhibit 50, 75, and 90% of cell growth (ED50, ED75, ED90)]. In an orthotopic mouse model where FLT3-ITD-positive MV4-11 cells were xenografted, mice treated with 75 mg 8-Cl-Ado/kg/day plus quizartinib (0.5 mg/kg/day) survived significantly longer than mice treated with the individual agents or vehicle alone (median survival 54.2 days vs. 27.3 days for controls, p=0.016).Taken together, these results support 8-Cl-Ado as a promising novel agent via a unique mechanism of action for FLT3-ITD AML, mediated by miR-155 degradation. 8-Cl-Ado also synergizes with TKIs both in vitro and in vivo thereby representing a potentially novel clinical approach for FLT3-ITD AML. A single-agent phase I/II clinical trial in relapsed/refractory AML is already ongoing at our institution. [Display omitted] DisclosuresWennerberg:Novartis: Research Funding. Gandhi:Pharmacyclics: Research Funding.

Gemtuzumab ozogamicin for treatment of newly diagnosed CD33-positive acute myeloid leukemia.

In September 2017, the US FDA announced re-approval of gemtuzumab ozogamicin (GO), a CD33-targeting immunoconjugate, for treatment of newly diagnosed and relapsed/refractory acute myeloid leukemia (AML). This is a very significant step toward defining new treatment regimens in AML, as the treatment has essentially stayed unchanged with the '7+3 induction regimen' (7 days cytarabine and 3 days of anthracycline) since 1973. GO is the first antibody-drug conjugate to receive FDA approval for treating cancer. This review article discusses the challenges faced and lessons learned during the journey of GO for AML treatment. Selected trials that have made significant contribution in our understanding of the most efficacious and safe use of GO for treating AML patients as well as factors influencing GO response are highlighted in this article.

Timed sequential therapy with high-dose cytarabine and mitoxantrone as an effective and safe induction regimen for acute myeloid leukemia.

7055Background: Traditionally, patients eligible for induction chemotherapy for AML are treated with the “7+3” regimen, which includes standard doses of infusional cytarabine and an anthracycline, ...

Clinical Efficacy of Decitabine Combined with or without Cytarabine-based Low Dose Regimen for Senile patients with Acute Myeloid Leukemia

To investigate the therapeutic effectiveness and side effects of decitabine combined with or without cytarabine-based low dose regimen for acute myeloid leukemia in geratic patients. Clinical data of 8 geratic patients (aged over 70 years) suffered from acute myeloid leukemia from September 2009 to March 2012 were analyzed retrospectively, including age, sex, peripheral blood and bone marrow characteristics and so on. These patients were treated by an 1-hour intravenous infusion of decitabine 20 mg/m2 per day for 5 consecutive days every 4 weeks combined with or without low dose regimen dominantly consisting of cytarabine 20 mg per day as subcutaneous injection for seven consecutive days. The therapeutic effectiveness and side-effects were evaluated. Among 8 patients, incinding 3 males and 5 females aged between 71-84 years old, their median white blood cell count was 31.2(1.38-179)× 109/L, and median bone marrow blast cell ratio was 42.7(23-94)% at the initial diagnosis.The median treatment courses was 2.5 (1-20).After treatment by this protocol,2 patients achieved complete remission(CR) (25%), 2 patients achieved partial remission (PR)(25%), 3 were not relieved, and 1 died, thus the overall response rate reached to 50% (4/8). The median overall survival time was 9.5 (2-36) months, and the overall survival time of 3 patients reached 1 year or more. The main side-effects of treatment were grade III-IV of myelosuppression (87.5%) and pneumonia (50%). Decitabine combined with or without cytarabine-based low dose regimen is promising for the treatment of geriatric acute myeloid leukemia, thus improving the overall response rate, and prolonging overall survival time.

Randomized phase II trial of cytosine arabinoside with and without the CHK1 inhibitor MK-8776 in relapsed and refractory acute myeloid leukemia

PurposeCytosine arabinoside (AraC) remains the backbone of most treatment regimens for acute myeloid leukemia (AML). Incorporation of AraC into DNA activates checkpoint kinase 1 (Chk1), leading to cell-cycle arrest and diminished AraC cytotoxicity, which can be reversed by the selective Chk1 inhibitor MK-8776. Building on a Phase I trial, we conducted a phase II trial comparing timed sequential AraC with or without MK-8776. MethodsPatients with relapsed or primary refractory AML were randomized 1:1 to receive either AraC with MK-8776 (Arm A); or AraC alone (Arm B). Results32 patients were treated: 14 assigned to Arm A and 18 to Arm B. There were 5 (36%) complete responses (CR/CRi) and 1 (7%) partial response (PR) in Arm A, and 8 (44%) CR/CRis and 1 (6%) PR in Arm B. Median survival did not differ significantly between the two groups (5.9months in Arm A vs. 4.5 months in Arm B). MK-8776 led to a robust increase in DNA damage in circulating leukemic blasts as measured by increased γ-H2AX (16.9%±6.1% prior and 36.4%±6.8% at one hour after MK-8776 infusion, p=0.016). ConclusionResponse rates and survival were similar between the two groups in spite of evidence that MK-8776 augmented DNA damage in circulating leukemic blasts. Better than expected results in the control arm using timed sequential AraC and truncated patient enrollment may have limited the ability to detect clinical benefit from the combination.

Pharmacometabolomics identifies dodecanamide and leukotriene B4 dimethylamide as a predictor of chemosensitivity for patients with acute myeloid leukemia treated with cytarabine and anthracycline.

Clinical responses to standard cytarabine plus anthracycline regimen in acute myeloid leukemia (AML) are heterogeneous and there is an unmet need for biological predictors of response to this regimen. Here, we applied a pharmacometabolomics approach to identify potential biomarkers associated with response to this regimen in AML patients. Based on clinical response the enrolled 82 patients were subdivided into two groups: complete remission(CR) responders (n=42) and non-responders (n=40). Metabolic profiles of pre-treatment serum from patients were analyzed by ultra-high performance liquid chromatography coupled with mass spectrometry and the metabolic differences between the two groups were investigated by multivariate statistical analysis. A metabolite panel containing dodecanamide and leukotriene B4 dimethylamide (LTB4-DMA) had the power capacity to differentiate the two groups of patients, yielding an area under the receiver operating characteristic of 0.945 (85.2% sensitivity and 88.9% specificity) in the training set and 0.944(84.6% sensitivity and 80.0% specificity) in the test set. The patients with high levels of LTB4-DMA and low amounts of dodecanamide had good sensitivity to chemotherapeutic agents. The possible reasons were that dodecanamide was produced by leukemic cells as a lipolytic factor to fuel their growth with a potential role in drug resistance and LTB4-DMA was a potent leukotriene B4 antagonist that could be applicable in the treatment of AML. These preliminary results demonstrates the feasibility of relating chemotherapy responses with pre-treatment metabolic profiles of AML patients, and pharmacometabolomics may be a useful tool to select patients that are more likely to benefit from cytarabine plus anthracycline chemotherapy.

APG-1252-12A induces mitochondria-dependent apoptosis through inhibiting the antiapoptotic proteins Bcl-2/Bcl-xl in HL-60 cells.

Acute myeloid leukemia (AML) is the most common acute leukemia in adults. Despite improved remission rates, current treatment regimens for AML are often associated with a very poor prognosis and adverse effects, necessitating more effective and safer agents. B-cell leukemia/lymphoma2 (Bcl-2) family proteins regulate apoptotic pathway that can be targeted with small molecule inhibitors. APG-1252-12A is a Bcl-2 homology (BH)-3 mimetic that specifically binds to Bcl-2 and Bcl-xl, which has shown efficacy in some Bcl-2 dependent hematological cancers. In this study, we investigated whether APG-1252-12A inhibits the growth of five leukemia cell lines in a concentration- or time-dependent manner by MTS assay. Following treatment of AML cell line HL-60 with this compound, cell apoptosis was detected using flow cytometry and nuclear condensation was observed after Hoechst33258 dye. Immunoblotting for cytochromec, cleaved caspase-3 and PARP-1 cleavage was used to demonstrate the mechanism of inducing mitochondria-dependent apoptosis by APG-1252-12A. Our findings showed that this new compound inhibited cell proliferation in five leukemia cell lines and induced apoptotic death. There was a link between the level of Bcl-2 protein and IC50. APG-1252-12A targeted mitochondria and induced caspase-dependent apoptosis by inducing the HL-60 cell cytochromec released, PARP cleavage and caspase activation. These data suggested that APG-1252-12A is a candidate drug for the invivo analysis and clinical evaluation in AML.

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.

Comparison of efficacy between high-dose CAG regimen and standard-dose cytarabine regimen for acute myeloid leukemia patients with partial remission after the first course of standard induction chemotherapy

Objective To compare the efficacy of high-dose CAG (HD-CAG) regimen by increasing the dose of aclarubicin in conventional CAG regimen and standard-dose cytarabine (SDAC) combination regimen in acute myeloid leukemia (AML) patients with partial remission (PR) after standard induction regimen. Methods This study retrospectively analyzed 49 PR AML patients after 3 days of daunorubicin or idarubicin and 7 days of cytarabine regimen (namely 3+7 ) in the First Affiliated Hospital of Soochow University and Haikou Municipal People's Hospital from October 2006 to September 2015. Based on different reinduction regimen, these patients were divided into 2 groups: HD-CAG (23 cases) and SDAC (26 cases). The clinical characteristics, efficacy, toxicity and survival rate were further evaluated between 2 groups. Results The complete remission (CR) rate in HD-CAG group was higher than that in SDAC group [91.3% (21/23) vs. 65.4% (17/26), P=0.030], while the overall response (OR) rate between 2 groups was not statically different [95.7% (22/23) vs. 84.6% (22/26), P=0.423]. Meanwhile, myelosuppression and infection rate of HD-CAG regimen were similar with SDAC regimen. There were no statistically significant differences in overall survival (OS) and disease free survival (DFS) rates at 12 months between 2 groups (P=0.287, P=0.816). Conclusion The HD-CAG regimen could obtain a better efficacy than SDAC regimen for these AML patients with PR after the first course of standard induction chemotherapy. Key words: Leukemia, myeloid, acute; High-dose CAG regimen; Standard-dose cytarabine; Induction chemotherapy

Impact of in vivo T cell depletion in HLA-identical allogeneic stem cell transplantation for acute myeloid leukemia in first complete remission conditioned with a fludarabine iv-busulfan myeloablative regimen: a report from the EBMT Acute Leukemia Working Party

BackgroundThe impact of the use of anti-thymocyte globulin (ATG) in allogeneic stem cell transplantation performed with HLA-identical sibling donors following fludarabine and 4 days intravenous busulfan myeloablative conditioning regimen has been poorly explored.MethodsWe retrospectively analyzed 566 patients who underwent a first HLA-identical allogeneic stem cell transplantation with this conditioning regimen for acute myeloid leukemia in first complete remission between 2006 and 2013 and compared the outcomes of 145 (25.6%) patients who received ATG (ATG group) to 421 (74.4%) who did not (no-ATG group). The Kaplan-Meier estimator, the cumulative incidence function, and Cox proportional hazards regression models were used where appropriate.ResultsPatients in the ATG group were older, received more frequently peripheral blood stem cell grafts from older donors, and were transplanted more recently. With a median follow-up of 19 months, patients in the ATG group had reduced 2-year cumulative incidence of chronic graft-versus-host disease (GVHD) (31 vs. 52%, p = 0.0002) and of its extensive form (8 vs. 26%, p < 0.0001) but similar relapse incidence (22 vs. 27%, p = 0.23) leading to improved GVHD and relapse-free survival (GRFS) (60 vs. 40%, p = 0.0001). In multivariate analyses, the addition of ATG was independently associated with lower chronic GVHD (HR = 0.46, p = 0.0001), improved leukemia-free survival (HR = 0.67, p = 0.027), overall survival (HR = 0.65, p = 0.027), and GRFS (HR = 0.51, p = 4 × 10−5). Recipient age above 50 years was the only other factor associated with worse survivals.ConclusionsThese results suggest that the use of ATG with fludarabine and 4 days intravenous busulfan followed by HLA-identical sibling donor allogeneic stem cell transplantation for acute myeloid leukemia improves overall transplant outcomes due to reduced incidence of chronic GVHD without increased relapse risk.

The PI3K/mTOR dual inhibitor BEZ235 suppresses proliferation and migration and reverses multidrug resistance in acute myeloid leukemia.

Aberrant activation of the PI3K/Akt/mTOR pathway contributes to the proliferation of malignant cells, and may confer resistance to chemotherapy in various malignancies, including acute myeloid leukemia (AML). Chemoresistance is the major reason for relapse in AML. RAD001 (everolimus) has been used at d1 and d7 of an induction chemotherapy regimen for AML, which has acceptable toxicity and may improve conventional chemotherapeutic treatment. Dual inhibitors of PI3K and mTOR overcome some of the intrinsic disadvantages of rapamycin and its derivatives. In this study, we evaluated the effects of BEZ235, a PI3K/mTOR dual inhibitor, on the multidrug-resistant AML cell lines HL-60/VCR and K562/ADR in vitro. BEZ235 dose-dependently inhibited the viability of HL-60/VCR and K562/ADR cells with the IC50 values of 66.69 and 71.44 nmol/L, respectively. BEZ235 (25-100 nmol/L) dose-dependently inhibited the migration of the two AML cell lines, and it also significantly sensitized the two AML cell lines to VCR and ADR. After treatment with BEZ235, the miR-1-3p levels were markedly increased in HL-60/VCR cells. Using TargetScan analysis and luciferase assays, we showed that miR-1-3p targeted BAG4, EDN1 and ABCB1, the key regulators of cell apoptosis, migration and multidrug resistance, and significantly decreased their levels in the two AML cell lines. Transfection of HL-60/VCR and K562/ADR cells with miR-1-3p-AMO to inhibit miR-1-3p could reverse the anti-proliferation effects of BEZ235. In conclusion, the PI3K/mTOR dual inhibitor BEZ235 effectively chemosensitizes AML cells via increasing miR-1-3p and subsequently down-regulating BAG4, EDN1 and ABCB1.

Acute myeloid leukemia in adolescents and young adults: from the viewpoint of physicians.

Based on various studies, the survival of adolescent and young adults (AYAs) with acute myeloid leukemia (AML) was reportedly similar to or worse than younger children. AYAs with AML treated in adult institutions are usually offered the same treatment as that of the older adults. Although pediatric protocols generally include intensified regimens compared with adult protocols, it is still controversial whether an intensified pediatric AML regimen results in an improved survival for the AYA population. Somatic mutations have proven to be significantly prognostic in AML. Although such molecular markers are becoming increasingly important as a means of risk stratification for both children and adults with AML, the prevalence and significance of somatic mutations remain largely unknown in AYAs with AML. In addition to the biological characteristics of cancer, non-biological factors, such as compliance with treatment, may influence the treatment outcomes of AYAs. AYAs have specific and unique needs that are different from children and older adults such as psychosocial care, transition from the pediatric to adult care environment, and fertility considerations among long-term survivors. A further multidisciplinary approach for AYAs with AML is still an issue among adult institutes.

SAMHD1 is a biomarker for cytarabine response and a therapeutic target in acute myeloid leukemia

The nucleoside analog cytarabine (Ara-C) is an essential component of primary and salvage chemotherapy regimens for acute myeloid leukemia (AML). After cellular uptake, Ara-C is converted into its therapeutically active triphosphate metabolite, Ara-CTP, which exerts antileukemic effects, primarily by inhibiting DNA synthesis in proliferating cells. Currently, a substantial fraction of patients with AML fail to respond effectively to Ara-C therapy, and reliable biomarkers for predicting the therapeutic response to Ara-C are lacking. SAMHD1 is a deoxynucleoside triphosphate (dNTP) triphosphohydrolase that cleaves physiological dNTPs into deoxyribonucleosides and inorganic triphosphate. Although it has been postulated that SAMHD1 sensitizes cancer cells to nucleoside-analog derivatives through the depletion of competing dNTPs, we show here that SAMHD1 reduces Ara-C cytotoxicity in AML cells. Mechanistically, dGTP-activated SAMHD1 hydrolyzes Ara-CTP, which results in a drastic reduction of Ara-CTP in leukemic cells. Loss of SAMHD1 activity-through genetic depletion, mutational inactivation of its triphosphohydrolase activity or proteasomal degradation using specialized, virus-like particles-potentiates the cytotoxicity of Ara-C in AML cells. In mouse models of retroviral AML transplantation, as well as in retrospective analyses of adult patients with AML, the response to Ara-C-containing therapy was inversely correlated with SAMHD1 expression. These results identify SAMHD1 as a potential biomarker for the stratification of patients with AML who might best respond to Ara-C-based therapy and as a target for treating Ara-C-refractory AML.