Ara-C Group Research Articles

Exploring the possible mitoprotective and neuroprotective potency of thymoquinone, betanin, and vitamin D against cytarabine-induced mitochondrial impairment and neurotoxicity in rats' brain.

It has been suggested that cytarabine (Ara-C) induces toxicity via mitochondrial dysfunction and oxidative stress. Therefore, we hypothesized that mitochondrial protective agents and antioxidants can reduce cytarabine-induced neurotoxicity. For this purpose, 48male Wistar rats were assigned into eightequal groups include control group, Ara-C (70 mg/kg, i.p.) group, Ara-C plus betanin (25 mg/kg, i.p.) group, Ara-C plus vitamin D (500 U/kg, i.p.) group, Ara-C plus thymoquinone (0.5 mg/kg, i.p.) group, betanin group, vitamin group, and thymoquinone group. The activity of acetylcholinesterase (AChE), and butyrylcholinesterase (BChE), the concentrations of antioxidants (reduced glutathione and oxidized glutathione), oxidative stress (malondialdehyde) biomarkers, mitochondrial toxicity parameters as well as histopathological alteration in brain tissues were measured. Our results demonstrated that Ara-C exposure significantly declines the brain enzymes activity (AChE and BChE), levels of antioxidant biomarkers (GSH),and mitochondrial functions, but markedly elevate the levels of oxidative stress biomarkers (MDA) and mitochondrial toxicity. Almost all of the previously mentioned parameters (especially mitochondrial toxicity) were retrieved by betanin, vitamin D, and thymoquinone compared to Ara-C group. These findings conclusively indicate that betanin, vitamin D, and thymoquinone administration provide adequate protection against Ara-C-induced neurotoxicity through modulations of oxidative, antioxidant activities, and mitochondrial protective (mitoprotective) effects.

SPARC Overexpression Enhances the Sensitivity of SKM-1 Cells to Ara-C by Regulating CPBP/MLKL

To investigate the effect of SPARC gene overexpression on the chemotherapeutic sensitivity of AML-MDS cell line SKM-1 to Ara-C and to further explore its mechanism. Subjects were divided into 6 groups: SKM-1 cells (Control), Negative control (LV-NC), SPARC overexpression (LV-SPARC), SKM-1 cells+30 ng/ml Ara-C (30 ng/ml Ara-C), LV-NC+30 ng/ml Ara-C and LV-SPARC+30 ng/ml Ara-C. Cell activity was detected by CCK-8 assay, cell cycle distribution and apoptosis were detected by flow cytometry, mRNA expression levels of SPARC, CPBP and MLKL were detected by RT-qPCR, and the expression levels of related protein were detected by Western blot. After co-treatment with SPARC overexpression and Ara-C, the cell viability decreased and apoptosis increased significantly, with obvious up-regulation of Bax and down-regulation of BCL-2 (P<0.05). Compared with the control group, the cell cycle of LV-SPARC+30 ng/ml Ara-C group was significantly arrested in S phase with obvious down-regulation of CDK2 and up-regulation of p27KIP1 (P<0.05). Compared with LV-SPARC group and 30 ng/ml Ara-C group, the mRNA and protein expression levels of CPBP and MLKL (p-MLKL) were significantly elevated in LV-SPARC+30 ng/ml Ara-C group (P<0.05). In addition, after co-treatment with SPARC overexpression and Ara-C, the protein expression level of p-AKT decreased and the protein expression level of p53 increased (P<0.05). SPARC overexpression enhanced the sensitivity of SKM-1 cells to Ara-C and promoted cell cycle arrest and apoptosis, the mechanism of which may be related to the regulation of CPBP/MLKL pathway.

P1217: INTRATHECAL METHOTREXATE PROPHYLAXIS AND CENTRAL NERVOUS SYSTEM RELAPSE IN PATIENTS WITH DIFFUSE LARGE B-CELL LYMPHOMA TREATED WITH INTENSIFIED R-ACVBP STRATEGY

Background: Central nervous system (CNS) relapse of diffuse large B-cell lymphoma is relatively uncommon (2-5%) and remains catastrophic with a median survival of 2 to 5 months. Intrathecal (IT) or intravenous high-dose methotrexate (HD MTX) have limited if any prophylactic impact on CNS relapse. We recently demonstrated in a cohort of 2203 patients included in multicenter clinical trials conducted by LYSA and GLA/ DSHNHL, that only 4 (1.6%) CNS relapses were seen with the R-ACVBP strategy in pts with aaIPI 2, 3 (and intermediate/high CNS-IPI), while 15 (3.9%) relapses did occur after R-(Mega)CHO(E)P. Aims: To address the role of IT in this intensified strategy R-ACVBP, we took the advantage of real world data of patients treated in four centers, and compared CNS relapses occurring in patients treated with R-ACVBP strategy with or without IT. Methods: The LYSA R-ACVBP strategy include four cycles of R-ACVBP (75 mg/m2 doxorubicin, and 1200 mg/m2 cyclophosphamide; 2 mg/m2 vindesine and 10 mg bleomycin on days 1 and 5) with four IT, two cycles of high dose methotrexate (3g/m2), four cycles of R-etoposide (300 mg/m2) and ifosfamide (1500 mg/m2) and 2 cycles of cytarabine(100 mg/m2) given sub cutaneously for 4 days. 233 patients with previously untreated diffuse large B-cell lymphoma (DLBCL) aged 18 to 59 years old received this intensified strategy between 2010 and 2020. We excluded 30 patients who received ASCT in first line and 10 others who received less than four cycles of R-ACVBP. We assessed the risk for of relapse and CNS-relapse. We also assesed the impact of the 2 courses of subcutaneous aracytine on overall survival (OS) and progression free survival (PFS). Results: A total of 193 pts were included. Median age was 44.4 years (IQR, 30.8-53, range: 17-62). Distribution of CNS IPI was not significantly different comparing IT (n=132) vs non-IT (n=61) groups within aaIPI categories (Table 1). 92 patients did not receive the two courses of subcutaneous Aracytine (no AraC group) for consolidation and 101 patients received the two courses (AraC group). With a median follow-up at 57.2 months, the 3 year OS and 3 year PFS of the whole cohort was 93.6% and 86.2%, respectively, without significant difference between IT and non IT groups in terms of OS (3yr-OS, = 92.3% versus 95.1%, HR= 1.29 (95%CI, 0.41 to 4.04, p=0.67) and PFS (3yr-PFS, 84.4% versus 90.1%, HR= 1.26 (95%CI, 0.59 to 2.72, p=0.55). The 3y-cumulative incidence of CNS relapse for pts treated IT group was 3.2% (95%CI, 1.0 to 7.4), and 3.3% (95%CI, 0.6 to 10.2) in the non-IT group (p= 0.93). In pts with aaIPI 1, two patients experienced a CNS relapse, one in the IT group and one in the non-IT group. In pts with aaIPI 2,3 and intermediate/high CNS IPI, 4 patients experienced a CNS relapse, three out of four in the IT group. 92 patients did not receive the two courses of subcutaneous Aracytine (no AraC group) for consolidation and 101 patients received the two courses (AraC group). Receiving or not AraC did not have any impact on the CNS relapse with a risk of CNS relapse at 4.1% (95%CI, 1.3 to 9.5) for patients receiving AraC and 2.2% (95%CI, 0.4 to 6.9) for patients not receiving AraC (p= 0.48). Image:Summary/Conclusion: CNS relapse was rare in younger DLBCL treated with this intensified strategy. Only 6 CNS relapses were observed without difference between IT and non-IT groups. The results presented at the EHA will included the total cohort of more than 600 patients.

Maternal supplementation of \u03b1-lipoic acid attenuates prenatal cytarabine exposure-induced oxidative stress, steroidogenesis suppression and testicular damage in F1 male rat fetus

BackgroundCytarabine (Ara-C) is an anticancer drug, which is considered as the mainstay in the treatment of hematological malignancies, known to cause various teratogenic effects. Alpha-lipoic acid (ALA) is a natural antioxidant and its supplementation proved to improve pregnancy outcomes in several pathological conditions. We aimed at exploring the benefits of maternal supplementation of ALA against in-utero Ara-C exposure-induced testicular toxicity in rat fetuses.MethodsPregnant rats (dams) received normal saline (control group), ALA 200 mg/kg (ALA group), Ara-C 12.5 mg/kg (Ara-C 12.5 group), Ara-C 25 mg/kg (Ara-C 25 group), and Ara-C 25 mg/kg + ALA 200 mg/kg (protection group) from gestational day (GD)8 to GD21. Ara-C and ALA were administered via the intraperitoneal and oral routes, respectively. The day of parturition was considered as postnatal day (PND)1. On PND1, all the live male pups were collected. The maternal parameters evaluated include (a) food intake, (b) bodyweight, and (c) oxidative stress (OS) markers. The fetal parameters evaluated include (a) bodyweight, (b) anogenital distances (AGD), (c) testicular weight (d) testicular testosterone levels (e) testicular histopathology, and (f) morphometrical parameters.ResultsA significant and dose-dependent decrease in maternal food intake, weight gain, and an increase in oxidative stress (OS) were observed in the pregnant rats of the Ara-C groups as compared to pregnant rats of the control group. Further, a significant and dose-dependent (a) reduction in bodyweight, AGD, testicular weight, and testosterone levels, (b) increase in OS, and (c) structural and morphometrical anomalies in fetal testes were observed in fetuses of Ara-C groups as compared to fetuses of the control rats. These deleterious effects observed in the Ara-C groups were found to be diminished in the pregnant rats and fetuses of the Protection group as compared to the pregnant rats and fetuses of the Ara-C 25 group.ConclusionsFrom the results of this study, we conclude that the maternal supplementation of ALA may ameliorate the Ara-C exposure-induced impairment in prenatal development and function of the testes in the rat fetuses. However, future experimental and clinical studies are warranted to explore the possible mechanisms involved in the protection offered by maternal supplementation of ALA against Ara-C induced testicular toxicity.Graphical

ML-08 Safety and efficacy of consolidation cytarabine for newly-diagnosed primary central nervous system lymphoma

Backgrounds: While consolidation therapies which incorporate whole brain radiotherapy (WBRT) and/ or chemotherapies such as high dose (HD)- cytarabine are commonly applied following induction chemotherapies in primary central nervous system lymphoma (PCNSL), the optimal treatment for consolidation therapy has not been established. We aimed to investigate the safety and efficacy of consolidation cytarabine with a dose modification policy in PCNSL. Patients and methods: PCNSL patients initially treated by R-MPV (rituximab, methotrexate, procarbazine and vincristine) and subsequently treated either by WBRT of 24Gy followed by cytarabine (WBRT-AraC group), or cytarabine alone (AraC group) were identified. WBRT was deferred in patients 71 years old or younger who had obtained a complete response (CR) after R-MPV. Cytarabine was dose-modified according to age groups (3 g/m2 in patients 70 years old or younger, 2 g/m2 in patients aged 71–75 years, 1 g/m2 in patients aged 76–80 years). Toxicity profiles, progression-free survival (PFS), overall survival (OS) were analyzed. Results: Twenty-five patients were identified (median age: 69 [range: 34–80], median KPS:70 [range: 40–90]), including 11 patients from the WBRT-AraC group, and 14 patients from the AraC group. Median PFS was unreached in the WBRT-AraC group, and 41.8 months in the AraC group. Median OS was unreached in both groups. The overall rate of grade 3/4 hematologic toxicities was high (92%), but mostly manageable without major complications. Fourteen patients received 3 g/m2, 4 patients received 2 g/m2, 7 patients received 1 g/m2 of cytarabine, and the rate of grade 4 leukopenia/ thrombocytopenia was 64%/57%, 25%/50%, and 29%/29%, respectively. Discussion: HD-cytarabine consolidation therapy with dose modification according to age groups for PCNSL was feasible and well-tolerated in patients 80 years of age or younger. The efficacy of HD-cytarabine was undetermined and further investigation is warranted.

Abstract 6298: 2D ex vivo patient derived acute myeloid leukemia platform for evaluation of novel molecular targeted therapeutic agents

Abstract Acute myelogenous leukemia (AML) is the most common acute leukemia in adults. Despite advances in treatment, long-term survival for AML remains poor and development of novel treatments is an unmet need. Due to highly divergent subtypes and mutation profiles in AML, use of patient-derived models may improve drug discovery and development. To address this, we have established a short-term culture system that supports growth of primary AML cells ex vivo to permit evaluation and/or screening of candidate therapeutic agents. Our AML bank is comprised of patient-derived specimens across a range of subtypes (which includes M1, M2, M4, M5, NOS and others), and includes models with common mutations in FLT3 (ITD), IDH1/IDH2 and NPM. Primary AML specimens were characterized for common mutations by TruSight sequencing and for surface marker expression by flow cytometry. The ex vivo assay system was evaluated for the ability to support survival and expansion of primary AML specimens. Among these, majority of the models showed evidence of proliferation, a few models had no net expansion, and some failed to survive. Extension of culture period for up to 14 days was feasible, with most models having equal or increased cell numbers by end of the culture period. All models stably expressed CD33 throughout the assay. To verify the applicability of this system for drug testing, a standard of care agent cytarabine (Ara-C) was assessed. A small cohort of models with distinct mutations were tested for sensitivity towards small molecule inhibitors venetoclax, gilteritnib, glasdegib, panobinostat and Ibrutinib. Cell growth/viability was assessed using Cell titer-Glo assay. Concentration-dependent responses to Ara-C were observed across multiple models (IC50 10 nM to 150 nM), indicating a range of relatively sensitive to resistant AML models. Heterogeneous concentration-dependent responses were observed across multiple patient-derived ex vivo models when treated with venetoclax, glasdegib, gilteritnib, ibrutinib and panobinostat, with both sensitive and resistant models identified. A cohort of models were evaluated in vivo for sensitivity to Ara-C. Systemic engraftment of the patient-derived xenograft AML models (into NOG or NOG-EXL mice) was evaluated by flow cytometry. When engrafted, AML-bearing mice were randomized into Ara-C or vehicle control groups. Two weeks later, mice were evaluated for the presence of human CD45+CD33+AML cells. Models that were relatively sensitive to Ara C ex vivo (IC50 &amp;lt; 30 nM) generally showed a greater in vivo response as evidenced by significant reduction in the mean circulating AML cells versus models with IC50 values &amp;gt;100 nM that had no response to Ara C in vivo. The diversity in these AML models is reflective of patient diversity, enhancing their utility in the evaluation of novel therapeutic candidates. These data indicate the feasibility of utilization of these primary models, ex vivo as well as in vivo, for drug discovery for AML, from screening to preclinical efficacy modeling. Citation Format: Bhavna Verma, Nikolett Biel, Amy Wesa. 2D ex vivo patient derived acute myeloid leukemia platform for evaluation of novel molecular targeted therapeutic agents [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 6298.

Higher efficacy of intermediate dose cytarabine + G-CSF compared to cyclophosphamide + G-CSF in hematopoietic stem cell mobilization in patients with multiple myeloma.

There are several regimens used in hematopoietic stem cell (HSC) mobilization in multiple myeloma (MM). Cyclophosphamide (Cy) is one of the most commonly used agents, although it does not always result in collecting adequate number of CD34+ cells. Recently, cytarabine (Ara-C) has been proposed as potentially efficient and safe option. Since the data regarding Ara-C in HSC mobilization is limited, the aim of our study was to compare retrospectively the efficiency and toxicity of G-CSF combined with either Ara-C or Cy in MM patients. Of a total of 89 patients, 43 received low or intermediate doses of Cy, and 46 were treated with 800 mg/m2 /day of Ara-C administered for two days. The mean peak of CD34+ cells/ul in peripheral blood was 132 (range, 84-202) in Ara-C and 51 (range, 29-69) in Cy cohort (p < 0.001). The median number of collected CD34+ cells (×106/kg) was 10.3 (range, 4.2-17.9) vs 4.5 (range, 2.7-8.9), respectively (p < 0.001). Mobilization failure was observed in one patient in Ara-C cohort (2%) and in 8 patients treated with Cy (19%) (p = 0.013). In the Ara-C group 98% of patients obtained more than 4×106 CD34+ cells/kg required for tandem transplantation. Moreover, we observed a trend toward increased paraprotein levels measured at transplant compared to before HSC mobilization in Ara-C cohort and significantly higher transfusion rates in that group. Our findings confirm higher HSC mobilization efficacy of Ara-C compared to Cy in MM patients. However, lower transfusions rate and better disease control of Cy may justify its use in some cases.

In Vivo Assessment of the Next Generation Microtubule-Destabilizing Agent AB8939 in Patient-Derived Xenograft Models of Acute Myeloid Leukemia

AB8939 is a novel, synthesized, small-molecule microtubule-destabilizer drug with proven prolific and potent in vitro activity against numerous cancer cell lines. In vitro and ex vivo studies (reported separately) have determined that AB8939 is well-suited for the treatment of hematopoietic tumors, in particular relapsed/refractory or poor-prognosis acute myeloid leukemia (AML), notably being able to circumvent two major resistance mechanisms associated with AML (i.e. P-glycoprotein and myeloperoxidase-mediated resistance). The therapeutic potential of AB8939 was investigated further through a series of in vivo experiments using three patient derived xenograft (PDX) mouse models and a cytarabine (Ara-C) resistant mouse model (MOLM14). MOLM14 cells and selected PDX primary cells were transduced to constitutively express luciferase for bioluminescence monitoring of tumor growth. In an Ara-C-sensitive AML PDX mouse model (ex vivo IC50 response to Ara-C in survival/proliferation assays was 0.82 µM), AB8939 (6 mg/kg in weekly cycles of 5 consecutive days) showed a statistically significant, 10-fold decrease in the amount of blasts detected in blood following 14 days of treatment compared with control, and a superior treatment effect compared with Ara-C (single cycle of 10 mg/kg twice per day for 4 consecutive days) in terms of decreased blasts in blood. In an Ara-C-refractory AML PDX mouse model (ex vivo IC50 response to Ara-C in survival/proliferation assays was 6.4 µM), animals treated with single agent AB8939 (6 mg/kg in weekly cycles of 5 consecutive days) showed reduced disease progression compared with control and Ara-C (single cycle of 10 mg/kg twice per day for 4 consecutive days) as evidenced from at least 10-times fewer blasts in blood, spleen and bone marrow following 28 days of treatment. This effect was even more pronounced for the combination treatment of AB8939 and Ara-C, suggesting a synergistic response. In a PDX mouse model that is highly resistant to Ara-C (ex vivo IC50 response to Ara-C in survival/proliferation assays was 8.3 µM), AB8939 as a single agent or in combination with Ara-C showed a significant (P &lt;0.001) decrease in tumor growth and reduction of blasts in blood with respect to Ara-C and control, following 27 days of treatment (8 animals per group). This improvement translated to survival benefit, with the single agent AB8939 cohort having a median survival of 89 days compared with 69 days and 65.5 days in the control and Ara-C cohorts, respectively. Indeed, all animals treated with single agent AB8939 were still alive at D83 post injection, which was 30 days after treatment was stopped. AB8939 as a single agent was well-tolerated with no toxicity-related deaths or impact on body weight. A greater treatment effect was again observed for the AB8939 plus Ara-C combination; however, clear signs of higher toxicity mean it will be imperative to optimize dosage of both AB8939 and Ara-C if used in combination. For the well-established xenografted MOLM14 mouse model, immune-deficient NSG (NOD scid gamma) mice (5 animals per group) were injected intravenously with MOLM14-luciferase cells and treated over a period of 21 days with single agent AB8939 (subcutaneous injection) at a dosage of 6 mg/kg every day or 12 mg/kg every other day; Ara-C (intraperitoneal injection, single cycle of 10 mg/kg twice per day for 4 consecutive days); or vehicle. AB8939 caused a significant dose-dependent reduction in tumor volume (p=0.001) and increased survival with respect to control or single agent Ara-C (median survival at 6 and 12 mg/kg was 39 and 42 days, respectively, corresponding to a 60% improvement compared with the control and Ara-C groups). A similar dosing schedule study showed single agent AB8939 at 6 mg/kg administered over 6 consecutive days (6 ON/1 OFF) was optimal with this cohort having a median survival of 59 days, corresponding to a 100% improvement over control. Overall, these in vivo data provide compelling proof-of-concept for AB8939 as a treatment of AML. AB8939 administered alone or in combination with Ara-C was demonstrated to significantly increase survival and reduce tumor growth as compared with single agent Ara-C in relevant animal models of AML. A first in human, phase 1 trial evaluating AB8939 in AML patients unfit to receive intensive chemotherapy in second and third-line has been initiated. Disclosures Goubard: AB Science: Employment. Humbert:AB Science: Employment. Mansfield:AB Science: Employment, Patents &amp; Royalties. Hermine:AB Science: Membership on an entity's Board of Directors or advisory committees. Dubreuil:AB Science: Employment, Membership on an entity's Board of Directors or advisory committees, Research Funding. AB8939 Study Group:AB Science: Consultancy, Employment.

Effect of miRNA-19a antisense oligonucleotide and Ara-C on the proliferation and apoptosis of HL60 cells.

This study aimed to investigate the effects of microRNA19a (miR-19a) antisense oligonucleotide (ASODN) on the proliferation and apoptosis of acute myeloid leukemia cells (HL60). In experiment 1, HL60 cells were divided into the blank control group, the blank transfection group, the scrambled oligonucleotide (SODN) group and the ASODN group. MiR-19a ASODN and SODN were independently transferred into HL60 cells. The miR-19a expression was detected by real-time quantitative RT-PCR (qRT-PCR) after 48-h and 72-h transfection; CCK8 assay was used to detect the proliferation inhibition rate at 48 and 72 h; Hoechst 33258 staining was performed to examine apoptotic cells at 48 h; the apoptosis rate was detected by flow cytometry after AnnexinV/PI staining at 48 and 72 h; the protein expression of E2F1 and Bim was detected by Western blotting at 48 h. In experiment 2, cells were divided into the Ara-C group, the SODN + Ara-C group and the ASODN + Ara-C group. The cell proliferation inhibition rate at 48 and 72 h and apoptosis rate at 72 h were assessed as mentioned above. MiR-19a expression in the miR-19a ASODN group was lower than in the SODN group and the blank control group (P<0.05). MiR-19a ASODN significantly inhibited the growth of HL60 cells (P<0.05) and increased their apoptosis, and the apoptosis rate peaked at 48 h. The protein expression of E2F1 and Bim in the ASODN group was higher than in the blank control group, blank transfection group and SODN group. In addition, Ara-C further inhibited the growth and induced the apoptosis of miR-19a ASODN-transfected cells (P<0.05) in a time dependent manner. The growth inhibition rate and apoptosis rate in the ASODN + Ara-C group were higher than the sum of those in both Ara-C group and ASODN group. miRNA-19a ASODN can inhibit the proliferation and induce apoptosis of HL60 cells and may exert synergistic effects with Ara-C on HL60 cells.

Role of cytarabine in paediatric acute promyelocytic leukemia treated with the combination of all-trans retinoic acid and arsenic trioxide: a randomized controlled trial

BackgroundThe combination of all-trans-retinoic acid (ATRA) and arsenic trioxide (ATO) has been suggested to be safe and effective for adult acute promyelocytic leukaemia (APL). As of 2010, the role of cytarabine (Ara-C) in APL was controversial. The aim of this study was to test the efficacy and safety of ATRA and ATO in paediatric APL patients. Also, we assessed whether Ara-C could be omitted in ATO and ATRA- based trials in children.MethodsWe performed a randomized controlled trial in paediatric APL patients (≤14 years of age) in our hospital from May 2010 to December 2016. All of the patients were assigned to receive ATRA plus ATO for induction followed by one course of idarubicin (IDA) and ATO (28 days). The patients were then randomly assigned to receive two courses of daunorubicin (DNR, no- Ara-C group) or DNR + Ara-C (Ara-C group). All of the patients were followed with maintenance therapy with oral ATRA, 6-mercaptopurine, and methotrexate for 1.5 years.ResultsAmong the 66 patients, 43 were male and 23 were female. All of the patients achieved complete remission (CR) with the exception of one who gave up the treatment. During induction therapy, all toxicity events were reversed after appropriate management. Thirty patients in the Ara-C group underwent 57 courses of treatment, and 35 patients in the no-Ara-C group underwent 73 courses of treatment. No significant differences in age, genders, white blood cell counts, haemoglobin levels, and platelet counts were found between the Ara-C and no-Ara-c groups. Greater myelosuppression and sepsis were observed in the Ara-C group during the consolidation courses. No patient died at consolidation, and only one patient relapsed. No differences were found in event-free survival, disease-free survival and overall survival between the two groups. Additionally, our analysis of the arsenic levels in the plasma, urine, hair and nails of the patients indicated that no significant accumulation of arsenic occurred after ATO was discontinued for 12 months.ConclusionsOverall, ATO and ATRA are safe and effective for paediatric APL patients and Ara-C could be omitted when ATO is used for two courses.Trial registrationClinicalTrials.gov (NCT01191541, retrospectively registered on 18 August 2010).

Comparison of Clinical Efficacy of Cytarabine with Different Regimens in Postremission Consolidation Therapy for Adult t(8;21) AML Patients: A Multicenter Retrospective Study in China

Background: The survival of patients with acute myeloid leukemia (AML) with t(8;21) was reported to be shorter in China than in other countries. Patients: We analyzed the correlation between different cytarabine (Ara-c) regimens and outcome in 255 t(8;21) AML patients in China who received postremission consolidation chemotherapy only. Results: The 5-year overall survival (OS) of the high-dose Ara-c group (HDAC; 2≤ Ara-c ≤3 g/m²), intermediate-dose Ara-c group (MDAC; 1.0≤ Ara-c <2.0 g/m²), low-dose Ara-c group (LDAC; 0.2< Ara-c <1.0 g/m²) and standard-dose Ara-c group (SDAC; 0.1≤ Ara-c ≤0.2 g/m²) were 65.3, 39.4, 25.2 and 27.9%, respectively (p = 0.003). In the HDAC group, but not in the MDAC group, the 5-year OS of patients who achieved 3-4 cycles of chemotherapy was superior to those who underwent 1-2 cycles (84.4 vs. 43.6%, p < 0.05), and the 3-year OS of patients who achieved an accumulated 36 g/m² of Ara-c was significantly higher compared to those who did not (85.3 vs. 39.2%, p < 0.05). Multivariate analysis indicated that factors such as WBC >3.5 × 10⁹/l, PLT ≤30 × 10⁹/l, and extramedullary infiltration were associated with a poor prognosis. Conclusion: The survival of t(8;21) AML patients treated with high-dose Ara-c (≥2 g/m²) was superior to other dose levels in postremission consolidation chemotherapy. Patient survival was improved by 3-4 cycles of chemotherapy with an accumulated concentration of 36 g/m² of Ara-c. WBC >3.5 × 10⁹/l, PLT ≤30 × 10⁹/l and extramedullary infiltration could be indicative of a poor clinical prognosis.

Is Arsenic Trioxide (ATO) Required in the Treatment of Standard Risk Newly Diagnosed APL? Analysis of a Randomized Trial (APL 2006) By the French Belgian Swiss APL Group

57th Annual Meeting of the American-Society-of-Hematology Location: Orlando, FL Date: DEC 05-08, 2015

Increased efficacy of intermediate-dose cytarabine + G-CSF compared to DHAP + G-CSF for stem cell mobilization in patients with lymphoma: an analysis by the polish lymphoma research group.

Salvage regimens, like DHAP (dexamethasone, cytarabine, and cisplatin) are frequently used for stem cell mobilization in lymphoma. The aim of this study was to compare the efficacy of DHAP + G-CSF with intermediate-dose cytarabine (ID-AraC) + G-CSF, recently proposed as an alternative schedule. Consecutive patients with Hodgkin's or non-Hodgkin lymphoma who had received at least 2 lines of chemotherapy, mobilized with either DHAP (n = 51) or ID-AraC (n = 50) + G-CSF were included in the analysis. AraC was administered at the dose of 400mg/m [1] bid intravenously for 2days followed by filgrastim starting from day 5. In the AraC group, 96% of patients collected at least 2 × 10 [2] CD34(+) cells/kg compared to 71% in the DHAP group (p = 0.0006). The CD34(+) cell yield was 9.3 (0-30.3) × 10 [2]/kg vs. 5.6 (0-24.8) × 10 [2]/kg, respectively (p = 0.006). A single apheresis was sufficient to achieve the threshold number of CD34(+) cells in 82% of the cases after AraC compared to 45% after DHAP (p = 0.001). We conclude that stem cell mobilization using ID-AraC is associated with a significantly higher efficacy than DHAP, allowing for collection of the transplant material in almost all patients with lymphoma. Our observation suggests that ID-AraC + G-CSF may be a preferable mobilization regimen in this setting.

Hematopoietic Cell Transplantation after TBI, Fludarabine, Idarubicine and Cytarabine Myeloablative Conditioning in Patients with Acute Myeloid Leukemia

▪IntroductionCombination of total body irradiation, fludarabine, cytarabine and idarubicine (TBI/Flu/AraC/Ida) is a disease-specific myeloablative conditioning regimen used in patients with acute myeloid leukemia. We report a single centre retrospective analysis of outcomes of allogeneic hematopoietic cell transplantation (allo-HCT) in patients with AML treated with TBI/Flu/AraC/Ida in comparison to TBI/Cy.MethodsPatients in the TBI/Flu/AraC/Ida arm received 12 Gy total body irradiation in 6 fractions on days -3 to -1, fludarabine 25mg/m2 on days -7 to -1, cytarabine 2000mg/m2 on days -7 to -3 and idarubicine 10mg/m2 on days -7,-5 and -3. Patients in TBI/Cy arm received 12Gy TBI in 6 fractions on days -3 to -1 and cyclophosphamide 60mg/kg on days -7 and -6.GvHD prophylaxis consisted of cyclosporine and methothrexate prior to year 2004. Since 2004, GvHD prophylaxis included cyclosporine with mycophenolate mofetil and ATG-Fressenius 20 – 40mg/kg was given to patients with unrelated donors.ResultsSixty four patients with AML received allo-HCT using TBI/Flu/Ida/AraC conditioning regimen between 2004 and 2012. Fifty three patients received TBI/Cy conditioning between 1987 and 1998 and between 2009 and 2014. Median age was 46 (range: 19-60) and 42 (range: 14-59) TBI/Flu/Ida/AraC and TBI/Cy, respectively.In the TBI/Flu/Ida/AraC group, 19 (30%) of patients received transplant from a HLA matched sibling donor, 16 (25%) from a HLA matched unrelated donor and 29 (45%) from HLA mismatched unrelated donor. In the TBI/Cy group, 24 (45%) of patients received transplant from a HLA matched sibling donor, 20 (38%) from a HLA matched unrelated donor and 9 (17%) from HLA mismatched unrelated donor (p = 0.0049). Other baseline patient and donor characteristics (patient/donor gender, CMV serology, AB0 matching, cytogenetic risk group, disease status and HCT-CI comorbidity score, ATG use) were not significantly different between the groups.Median time to neutrophil engraftment was 18 days (range 10 - 31) and 21 days (range 12 – 32) in TBI/Flu/AraC/Ida a TBI/Cy groups, respectively. Median time to platelet engraftment to more then 20G/l was 21 (range 12 – 103) and 22.5 (range 9 – 54) days, respectively. Among patients who survived more than 100 days, 2/45 patients did not engraft platelets in the TBI/Flu/AraC/Ida group and 3/35 in the TBI/Cy group.Overall survival (OS) at 2 years was 35% (95% CI: 25 – 49%) in TBI/Flu/Ida/AraC group and 47.5% (95% CI: 35 – 65%) in TBI/Cy group. Two years disease free survival (DFS) was 35% (95% CI: 25 - 49) in TBI/Flu/Ida/AraC group and 40% (95% CI: 27 - 58) in TBI/Cy group.Cumulative incidence of relapse at 2 years after transplant was 12.5% and 25% (p = 0,08), and the cumulative incidence of non-relapse mortality was 53% and 36% (p = 0.059) in the TBI/Flu/Ida/AraC and TBI/Cy groups, respectively.Survival curves and relapse incidence curves are presented in Figure 1.In multivariate analysis of the influence of baseline characteristics and conditioning regimen on OS and DFS, only HLA mismatch was significantly associated with increased risk of mortality with HR 2,22 (95% CI: 1,25 – 3,95). HR of death was 1.11 (95% CI: 0.62 – 1.98) and HR of death or relapse was 0.87 (95% CI: 0.50 - 1.52) in patients who recieved TBI/Flu/Ida/AraC.There was a trend towards increased incidence of acute graft versus host disease (aGVHD) grade II-IV in the TBI/Flu/AraC/Ida group (p = 0,09). The cumulative incidence of aGVHD was 46% and 34% in the TBI/Flu/AraC/Ida and TBI/Cy groups, respectively. Estimates of the cumulative incidence of aGVHD in the presence of competing risk of relapse or death are shown in Figure 2.ConclusionTBI/Flu/Ida/AraC regimen led to similar OS and DFS as TBI/Cy. There was a trend towards decreased rate of relapse, but increased non-relapse mortality with the TBI/Flu/Ida/AraC conditioning. In multivariate analysis, only HLA mismatch had significant effect on patient outcome.The retrospective nature of the study and inequalities in baseline transplant characteristics, mainly more frequent use of mismatched unrelated donors in the TBI/Flu/Ida/AraC group, are main limitations of the study. [Display omitted] DisclosuresOff Label Use: Fludarabine, Cytarabine and Idarubicine as part of conditioning regimen.

Experimental study on aging effect of Angelica sinensis polysaccharides combined with cytarabine on human leukemia KG1α cell lines

The latest findings of our laboratory showed that Angelica sinensis polysaccharide( ASP) showed a definite effect in regulating the aging of hematopoietic stem cells. Leukemia is a type of malignant hematopoietic tumor in hematopoietic stem cells. There have been no relevant reports about ASP's effect in regulating the aging of leukemia cells. In this study,human acute myeloid leukemia( AML) KG1α cell lines in logarithmic growth phase were taken as the study object,and were divided into the ASP group, the cytarabine( Ara-C) group,the ASP + Ara-C group and the control group. The groups were respectively treated with different concentration of ASP,Ara-C and ASP + Ara-C for different periods,with the aim to study the effect of ASP combined with Ara-C in regulating the aging of human acute myeloid leukemia KG1α cell lines and its relevant mechanism. The results showed that ASP,Ara-C and ASP + Ara-C could obviously inhibit KG1α cell proliferation in vitro,block the cells in G0/ G1phase. The cells showed the aging morphological feature. The percentage of positive stained aging cells was dramatically increased,and could significantly up-regulate the expression of aging-related proteins P16 and RB,which were more obvious in the ASP + Ara-C group. In conclusion,the aging mechanism of KG1α cell induced by ASP and Ara-C may be related to the regulation of the expression of aging-related proteins,suggesting that the combined administration of ASP and anticancer drugs plays a better role in the treatment of leukemia.

Effect of salidroside on apoptosis of bone marrow mesenchymal stem cells induced by ara-C

The purpose of this study was to investigate the effect of salidroside on human bone marrow mesenchymal stem cell (hBMMSC) apoptosis induced by cytarabine C (Ara-C) and its mechanism, hBMMSC were cultured in vitro and isolated by Fircoll density gradient centrifugation; cell surface antigens were measured by flow cytometry; the osteogenic and adipogenic differentiation of MSC was tested and evaluated by specific staining methods. The proliferation and apoptosis of cells exposed to Ara- C were detected by MTT and flow cytometry respectively. The experiments were divided into 4 groups: control group, Ara-C group, salidroside group and Ara-C+salidroside group. The mRNA expression of BCL-2 and BAX was assayed by RT-PCR. The results showed that the adherent cells displayed spindle and fibroblast cell-like shape; the hBMMSC expressed CD44, CD71 and HLA-ABC, not expressed CD34, CD45 and HLA-DR; the hBMMSC successfully differentiated into osteogenic and adipogenic lineages, which showed mineralization with von Kossa staining. Furthermore, liquid vacuoles were detected by oil red O staining; Ara- C exhibited a less inhibitory effect on the proliferation of hBMMSC treated with salidroside. The apoptosis of hBMMSC treated with salidroside were significantly higher as compared with control group (P < 0.05); RT-PCR results demonstrated that the BCL-2 expression was significantly down regulated but BAX mRNA expressions was up-regulated in Ara- C group as compared with those in the control group. Salidroside significantly inhibited the apoptosis of MSC and reversed the mRNA expression of BCL-2 and BAX. It is concluded that salidroside can inhibit the apoptosis of hBMMSC induced by Ara-C, its mechanism may be related with the regulation of BCL-2/BAX expression.

Arsenic Trioxide (ATO) Or ATRA For Consolidation Treatment Of Standard Risk Non Elderly Newly Diagnosed APL– Second Interim Analysis Of a Randomized Trial (APL 2006) By The French Belgian Swiss APL Group

▪ BackgroundATRA combined to anthracycline-based chemotherapy (CT) remains the classical treatment of newly diagnosed APL, but it is myelosuppressive and may be associated with long-term cardiac toxicity. Both ATO (Powell, Blood 2010) and ATRA (Sanz , Blood 2004) may allow to reduce the amount of CT and further diminish the relapse risk. In a randomized trial (APL 2006 trial), we compared for consolidation treatment ATO, ATRA and Ara C in standard risk APL ( ie with baseline WBC < 10G/L). MethodsIn this trial (started in Nov, 2006) newly diagnosed APL patients (pts) < 70 years with WBC < 10 G/L were randomized for consolidation between AraC, ATO and ATRA. The AraC group (standard group) received for induction: ATRA 45mg/m2/d until CR with Idarubicin (Ida) 12 mg/m2/dx3 and AraC 200mg/m2/dx7 started on day 3; first consolidation with the same CT course, second consolidation with Ida 9 mg/m2/dx3 and AraC 1g/m2/12h x4d ; maintenance during two years with intermittent ATRA 15d/ 3 months and continuous 6 MP + MTX,). The ATO and ATRA groups received the same treatment as the AraC group , but AraC was replaced respectively by ATO 0.15 mg/Kg/d d1 to 25 and ATRA 45 mg/m2/d d1 to 15 for both consolidation courses. We present here results of the second interim analysis, made at the reference date of 1st Jan 2012, in 349 pts aged < 70 years included in 78 centers before 2012. The primary endpoint was event free survival (EFS) at 2 years from CR achievement. Relapse, survival, side effects of the treatment and duration of hospitalization were secondary endpoints. ResultsPre-treatment characteristics were well balanced between the 3 consolidation groups. 347 pts (99.4 %) achieved CR, and 2 (0.5%) had early death. Overall, 3, 0, and 4 pts had relapsed and 5, 2, and 2 pts had died in CR in the AraC, ATO and ATRA consolidation groups, respectively. Two year EFS was 95%, 97.4% and 96.8% (p=NS) and 2 year OS was 96.6%, 97.4% and 99% (p=NS), in the AraC, ATO and ATRA consolidation groups, respectively. Median time to ANC >1 G/L and platelets > 50G/L after the first consolidation course was 24 and 25 days, 24 and 23 days, 17 and 20 days in the AraC, ATO and ATRA group, respectively (p<0.01). Similarly, time to ANC >1 G/L and platelets > 50G/L after the second consolidation course was 23 and 27 days, 19 and 18 days, 13 and 19 days in the AraC, ATO and ATRA group (p<0.01). The overall duration of hospitalization was 60.9, 63.1 and 33 days in in the AraC, ATO and ATRA groups, respectively (p<0.01). ConclusionVery high CR rates (close to 98-99%) are now obtained in standard risk APL on a very large multicenter basis using classical ATRA and anthracycline based CT combinations, with very few relapses. ATO or ATRA can replace AraC during consolidation cycles without increasing the relapse risk, and can possibly reduce the rate of deaths in CR (2 and 2 patients versus 5 patients, although the difference was NS). However Ida and ATO, when used concomitantly for consolidation cycles, proved as myelosuppressive as Ida-AraC cycles, while myelosuppression was reduced with Ida-ATRA consolidation courses. Disclosures:Off Label Use: ATO in the treatment of 1st Line APL.

Comparison Of Intensive Chemotherapy and Hypomethylating Agents Prior To Allogeneic Stem Cell Transplantation For Advanced MDS (RAEB, RAEB-T). A Study Of The MDS Subcommittee Of The Cmwp Of EBMT

Since the approval of hypomethylating agents for the treatment of myelodysplastic syndromes (MDS) increasing numbers of patients have received these agents prior to haematopoietic stem cell transplant (HSCT). A number of small studies have suggested that this approach results in similar outcomes to conventional chemotherapy. In light of this we utilised the EBMT dataset to retrospectively analyse the outcomes of hypomethylating agent (HMA) therapy compared with conventional chemotherapy (CC) or cytarabine (ara-C) alone pre-HSCTBecause hypomethylating agents were approved in early 2000, we selected MDS patients who received allogeneic stem cell transplantation between 2004 and 2011 reported to EBMT. In order to include a homogeneous group of patients with blasts at time of diagnosis we included only patients classified as RAEB or RAEB-T at time of diagnosis with sufficient data on anthracycline containing chemotherapy, hypomethylating agents or cytarabine. 234 MDS patients treated with hypomethylating agents (N=77), conventional anthracycline-based chemotherapy (N=132) or cytarabine (N-25) receiving myeloablative (N=94) or reduced intensity conditioned (RIC) HSCT (140), from sibling (N=101) or matched unrelated donors (N=133) were identified. 136 (58%) male and 98 (32%) females with a median age of 56 years (range 19-69) were included. The median follow-up of the cohort was 22.1 months (95%CI 0.7-94.3). Patients with >30% blasts were excluded. Cytogenetics were abnormal in 57%, 51% and 26% of patients receiving HMA, CC and ara-C respectively(p=0.04). Of the 77 patients treated with HMA, 73 had RAEB and 4 had RAEB-T, of the 132 patients receiving CC, 117 had RAEB and 11 had RAEB-T (missing data in 4) and of the 25 patients receiving ara-C 15 had RAEB and 1 RAEB-T (missing data in 9). Overall 127 patients (54%) achieved CR prior to HSCT with more CR in the CC group (68%) than either the HMA (32%) or ara-C (48%) groups (p<0.01). A number of patients achieved partial but not complete remission (non-CR) including 22% of patients receiving CC, 48% of patients receiving HMA and 24% of patients receiving ara-C. Primary refractory disease was noted in 10%, 19% and 28% of patients in CC, HMA and ara-C groups.On univariate analysis overall survival (OS), relapse free survival (RFS), and non-relapse mortality (NRM) did not differ significantly between those receiving HMA, CC or ara-C at three years; OS (42% vs 41% vs 54%), RFS (29% vs 36% vs 49%) and NRM (26% vs 26% vs 31%) respectively. The median OS for those treated with HMA was 31 months (10-not reached) vs 18months (13-45) for CC (p=NS). Results for sibling vs unrelated donor HSCT were similar for OS, RFS and relapse with worse outcomes for URD with respect to NRM (HR 1.74 (0.98-3.11) p=0.06). No significant difference in outcomes for standard vs RIC HSCT or normal vs abnormal cytogenetics was observed. When compared to patients in remission those in non-CR had significantly worse outcomes with regard to relapse (HR 1.75 (95%CI 1.05-2.91) p=0.03) and approached significance for RFS (HR 1.47 (95%CI(0.99-2.19) p=0.06). This was not evident for OS (HR 1.29(95%CI 0.83-2.01p=NS), or NRM (HR1.12 (0.58-2.16) p=NS). Patients with primary refractory disease had significantly worse outcomes across all parameters; OS(HR 2.81(95%CI 1.74-4.56) p=<0.01), RFS (HR 2.63 95%CI 1.67-4.16) p=<0.01), relapse (HR 2.32(95%CI 1.22-4.40) p=0.01) and NRM (HR 3(95%CI1.56-5.79) p<0.01). On multivariate analysis when adjusted for CR status at transplantation those receiving CC had inferior outcomes for OS compared to those receiving HMA (HR 1.54 (0.97-2.45), p = 0.07). For patients with primary refractory disease MVA demonstrated significantly worse outcomes for OS, RFS, CIR and NRM (HR 3.4, 3, 2.62 and 3.5 respectively p<0.01 for all).Whilst the inherent limitation of retrospective data analysis are acknowledged these findings support the growing body of evidence that HMA therapy is comparable to both CC and ara-C alone when used as pre-transplant induction treatment. Disease status is clearly important for best outcomes and the results of prospective studies which clarify the ability of hypomethylating agents vs other methods to achieve this are awaited. Disclosures:No relevant conflicts of interest to declare.

Long‐term follow‐up of European APL 2000 trial, evaluating the role of cytarabine combined with ATRA and Daunorubicin in the treatment of nonelderly APL patients

All-trans retinoic acid (ATRA) combined to anthracycline-based chemotherapy is the reference treatment of acute promyelocytic leukemia (APL). Whereas, in high-risk patients, cytarabine (AraC) is often considered useful in combination with anthracycline to prevent relapse, its usefulness in standard-risk APL is uncertain. In APL 2000 trial, patients with standard-risk APL [i.e., with baseline white blood cell (WBC) count <10,000/mm(3) ] were randomized between treatment with ATRA with Daunorubicin (DNR) and AraC (AraC group) and ATRA with DNR but without AraC (no AraC group). All patients subsequently received combined maintenance treatment. The trial had been prematurely terminated due to significantly more relapses in the no AraC group (J Clin Oncol, (24) 2006, 5703-10), but follow-up was still relatively short. With long-term follow-up (median 103 months), the 7-year cumulative incidence of relapses was 28.6% in the no AraC group, compared to 12.9% in the AraC group (P = 0.0065). In standard-risk APL, at least when the anthracycline used is DNR, avoiding AraC may lead to an increased risk of relapse suggesting that the need for AraC is regimen-dependent.

Intermediate-dose Ara-C plus G-CSF for stem cell mobilization in patients with lymphoid malignancies, including predicted poor mobilizers

The optimal protocol for mobilization of hematopoietic stem cells in patients with lymphoid malignancies has not been determined so far. We retrospectively analyzed the efficacy and safety of Ara-C at a dose of 1.6 g/m(2) compared with CY at a dose of 4.0 g/m(2), both combined with filgrastim. Seventy and forty-five patients, respectively, were included, among whom 60% were defined as 'predicted poor mobilizers'. The use of Ara-C was associated with significantly higher peak number of circulating CD34(+) cells compared with CY (P<0.0001). In the Ara-C group, 95% of patients with multiple myeloma (MM) collected at least 5 × 10(6) CD34(+) cells/kg required for tandem transplantation, and 97% of lymphoma patients collected at least 2 × 10(6) CD34(+) cells/kg, needed for a single autologous hematopoietic SCT (autoHSCT), which was achieved with a single leukapheresis in 91% of cases. Results for the CY group were significantly inferior (P<0.0001). No patient mobilized with Ara-C experienced febrile neutropenia, whereas 35% required platelet transfusions. Among patients who proceeded to autoHSCT, the time of both neutrophil and platelet recovery was significantly shorter for those mobilized with Ara-C than CY. We conclude that intermediate-dose Ara-C+filgrastim is a very effective and relatively safe mobilization protocol for patients with lymphoid malignancies.