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  • 1
    In: Blood, American Society of Hematology, Vol. 118, No. 21 ( 2011-11-18), p. 1505-1505
    Abstract: Abstract 1505 Asparaginase is an essential component of combination chemotherapy of acute lymphoblastic leukemia (ALL). Asparaginase breaks down asparagine into aspartic acid and ammonia. Because asparagine is necessary for protein synthesis, its depletion leads to cell death. Recently, it has been suggested that mesenchymal cells in the bone marrow may produce asparagine and form ‘protective niches’ for leukemic cells. In vitro, this led to high levels of asparagine and asparaginase resistance of the ALL cells (Iwamoto et al. (J Clin Invest. 2007)). However, it is unknown if this holds true for the clinical in vivo situation. The aim of our study is to analyse whether mesenchymal cells or other cells in the bone marrow indeed produce significant amounts of asparagine in vivo that may lead to clinical asparaginase resistance. Ten de novo ALL patients were enrolled in this study. All children received induction chemotherapy according to protocol 1-A and 1-B of the Dutch Childhood Oncology Group (DCOG) ALL-10 protocol. Asparaginase levels and amino acid levels (asparagine, aspartic acid, glutamine and glutamic acid) were measured in bone marrow (BM) and peripheral blood at diagnosis (day 1), days 15, 33 and 79. On days that asparaginase was administered (days 15 and 33) it was ensured that study material was obtained before the E-coli L-asparaginase infusions. Changes over time of asparaginase trough levels in BM and peripheral blood were evaluated using Mixed models ANOVA. The amino acids levels in 0.5 ml BM, 3 ml BM and peripheral blood at days 15 and 33 were also compared using Mixed models ANOVA. All these analyses were done after log transformation of measured values to get approximate normal distributions. A two-sided p-value 〈 0.05 was considered statistically significant. The asparaginase levels were all below detection limit ( 〈 5 IU/L) in BM and peripheral blood at days 1 and 79. In both compartments, the median asparaginase trough levels were not significantly different at days 15 and 33. At diagnosis, no significant difference in asparagine level between 3 ml BM and peripheral blood was found (median: 44.5 μM (range 20.6–59.6 μM) and 43.9 μM (range 18.4 –58.5 μM), respectively). However, the median level of aspartic acid at diagnosis in 3 ml BM (19.2 μM; range 6.2–52.6 μM) was significantly higher as compared to median level of peripheral blood (5.7 μM; range 2.4–10.1 μM) (p=0.002). The aspartic acid levels were also higher in BM compared to peripheral blood at days 15 and 33 (both p=0.001) and at day 79 (p=0.002). Aspartic acid levels were significantly higher in 0.5 ml versus 3 ml BM (p=0.001) and this difference was also found when comparing 0.5 ml BM versus peripheral blood (p 〈 0.001) suggesting dilution with peripheral blood when taking higher volumes of ‘bone marrow’. Asparagine levels were all below the lower limit of quantification (LLQ 〈 0.2 μM) in both BM and blood during asparaginase treatment at days 15 and 33. At day 79, no significant difference in asparagine levels between BM (37.7 μM; range 33.4–50.3 μM) and peripheral blood (38.9 μM; range 25.7 –51.3 μM) was seen. During the time course of asparaginase infusions, the glutamine and glutamic acid levels did not change significantly. In conclusion, we demonstrate higher aspartic acid levels in bone marrow compared to peripheral blood. The higher aspartic acid levels are detected at diagnosis, during asparaginase therapy at days 15 and 33, and also at day 79 at complete remission, showing that these do not originate from leukemic cells nor from asparagine breakdown by asparaginase but from cells in the microenvironment of the bone marrow. However, there is no increased asparagine synthesis in vivo in the bone marrow of ALL patients. Therefore, increased asparagine synthesis by mesenchymal cells may be of relevance for resistance to asparaginase of leukemic cells in vitro but not in vivo. Disclosures: No relevant conflicts of interest to declare.
    Type of Medium: Online Resource
    ISSN: 0006-4971 , 1528-0020
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    Language: English
    Publisher: American Society of Hematology
    Publication Date: 2011
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  • 2
    In: Blood, American Society of Hematology, Vol. 124, No. 21 ( 2014-12-06), p. 2256-2256
    Abstract: Purpose We prospectively studied the incidence and clinical course of hypertriglyceridemia and hypercholesterolemia during very prolonged use of PEGasparaginase or Erwinia asparaginase in relation to asparaginase activity levels in children with acute lymphoblastic leukemia (ALL). Also, the incidence of pancreatitis, thrombosis, hyperammonemia and central neurotoxicity and their association with asparaginase activity levels were evaluated. Patients and Methods Patients were treated according to Dutch Childhood Oncology Group (DCOG) ALL-10 medium risk intensification protocol, which includes 15 doses of PEGasparaginase (2,500 IU/m2) for 30 weeks. Erwinia asparaginase (20,000 IU/m2) was administered when an allergy to or silent inactivation of PEGasparaginase occurred. Definitions of silent inactivation of PEGasparaginase and Erwinia asparaginase were previously described (Tong et al., Blood, 2014 Mar;123(13):2026-33). Hypertriglyceridemia, hypercholesterolemia, hyperammonemia, pancreatitis, thrombosis and central neurotoxicity were graded according to the National Cancer Institute (NCI) Common Terminology Criteria for Adverse Events (CTCAE). Changes over time of triglyceride, cholesterol, and ammonia levels were evaluated using mixed models analysis of variance (ANOVA). Changes related to age and gender were also investigated using mixed models ANOVA. The incidence of toxicities (pancreatitis, thrombosis, central neurotoxicity) related to treatment (PEGasparaginase or Erwinia asparaginase) was investigated with the Fisher's exact tests. Finally, Spearman correlation coefficients were used to evaluate the relations between triglyceride, cholesterol, and asparaginase activity levels. Results In total, 89 patients were enrolled from two pediatric oncology centers. Triglyceride, cholesterol and ammonia levels increased rapidly in children with PEGasparaginase and remained temporary elevated, but normalized after the finishing the last asparaginase dose. Hypertriglyceridemia and hypercholesterolemia (grade 3/4) were found in 47% and in 25%, respectively, of the patients treated with PEGasparaginase. Studying the correlations between PEGasparaginase activity levels and triglyceride levels showed the strongest correlation at week 5 (Rs = 0.36, p=0.005). Children 〉 = 10 years had higher triglyceride levels as compared to younger patients ( 〈 10 years) adjusted for asparaginase preparations: median levels of 4.9 mmol/L versus 1.6 mmol/L (p 〈 0.001). In patients receiving Erwinia asparaginase, triglyceride levels increased in the first weeks as well, but no hypertriglyceridemia and hypercholesterolemia (grade 3/4) were found. Hyperammonemia (grade 3/4) was only found in Erwinia asparaginase treated patients (9%). No associations were found between pancreatitis and hypertriglyceridemia nor between ammonia and central neurotoxicity. Thrombosis occurred in 4.5%, pancreatitis in 7% and central neurotoxicity in 9% of the patients using each of both asparaginase agents; these toxicities were not related to asparaginase activity levels nor to triglyceride levels. Conclusions Severe dyslipidemia occurred frequently, but was temporary and was not associated with relevant clinical events and therefore should not be considered a reason for asparaginase treatment modifications. We show that high asparaginase activity levels are associated with high triglyceride and high cholesterol levels. However, pancreatitis, thrombosis and central neurotoxicity appear unrelated to asparaginase activity levels. Also, no associations were found between pancreatitis and hypertriglyceridemia and between ammonia level and central neurotoxicity. Table 1 Toxicity table, p-values are given for comparisons of grade 3/4 toxicities between both asparaginase agents, ns; not significant. PEGasparaginase (n=67) Erwinia asparaginase (n=22) p-value Grade 1/2 Grade 3/4 Grade 1/2 Grade 3/4 n % n % n % n % Pancreatitis 0 0 4 6 1 5 2 9 ns Hypertriglyceridemia 15 22 31 47 7 32 0 0 p 〈 0.001 Hypercholesterolemia 6 9 17 25 8 37 0 0 p=0.01 Hyperammonemia 34 51 0 0 9 41 2 9 ns Thrombosis 0 0 2 3 0 0 2 9 ns Central neurotoxicity 0 0 7 10 0 0 1 5 ns Disclosures Tong: EUSA Pharma: Research Funding.
    Type of Medium: Online Resource
    ISSN: 0006-4971 , 1528-0020
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    Language: English
    Publisher: American Society of Hematology
    Publication Date: 2014
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  • 3
    Online Resource
    Online Resource
    American Society of Hematology ; 2009
    In:  Blood Vol. 114, No. 22 ( 2009-11-20), p. 4803-4803
    In: Blood, American Society of Hematology, Vol. 114, No. 22 ( 2009-11-20), p. 4803-4803
    Abstract: Abstract 4803 Introduction Native Escherichia Coli Asparaginase (ASNase) is an integral component in the therapy of acute lymphoblastic leukemia (ALL) and non-Hodgkin's Lymphoma (NHL). There is a great interindividual variability in treatment intensity in patients treated with the same dose of ASNase. Population pharmacokinetics (PopPK) provides the possibility to divide the overall variability of a population in an inter- and intraindividual element and to develop more precise dosing recommendations. Furthermore, pharmacokinetic parameters can be estimated as well as possible covariates that may influence the pharmacokinetics of the drug can be identified. Patients and Methods The model building dataset consisted of 16 patients (233 samples) receiving 5000 U/m2 ASNase (Asparaginase Medac®) 8 times according to the DCOG-ALL 10 treatment protocol. Asparaginase activity was measured in a randomized clinical Phase 2 study comparing the pharmacokinetic and pharmacodynamic of a newly developed recombinant ASNase with that of the established ASNase (Asparaginase Medac®)[R. Pieters et al. Blood. 2008 Dec 15. 112(13):4832-8]. The PopPK-model was developed using NONMEM (version VI) with First Order Conditional Estimation (FOCE) method and INTERACTION option. Results A linear 2-compartmental model with a combined proportional (0.9%) and additive (48.1U/l) error model described the data adequately. The pharmacokinetic parameters estimated were: Total systemic clearance 0.135 ± 12.8% l/h/70kg, volume of distribution of the central compartment 4.27 ± 13.1% l/70kg, volume of distribution in the peripheral compartment 0.83 ± 80.4% l/70kg and intercompartmental clearance 0.058 l/h/70kg (mean ± interindividual variability). Body weight was identified as the most important covariate. Validity of the model was verified by simulating different dosages of ASNase (2500U/m2 and 10000U/m2) in induction and reinduction of the ALL-BFM treatment protocol. The median and mean ASNase activity was compared with published data [E. Ahlke et al. Br J Haematol. 1997 Mar. 96(4):675-81 and Boos et al. Eur J Cancer. 1996 Aug. 32A(9):1544-50] . Furthermore pharmacokinetic data obtained by a noncompartmental analysis [R. Pieters et al. Blood. 2008 Dec 15.112(13):4832-8] were compared with the pharmacokinetic data estimated by the PopPK model. Both procedures indicated on face validity of the PopPK model. Conclusion This PopPK analysis provides the first step in the development of a PopPK model for ASNase. Face validity of the PopPK model could be demonstrated and will be confirmed with an independent dataset. Disclosures: Pieters: Medac GmbH: Research Funding. Kuehnel:Medac GmbH: Employment. Boos:Medac GmbH: Honoraria. Hempel:Medac GmbH: Honoraria.
    Type of Medium: Online Resource
    ISSN: 0006-4971 , 1528-0020
    RVK:
    RVK:
    Language: English
    Publisher: American Society of Hematology
    Publication Date: 2009
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  • 4
    In: Pediatric Blood & Cancer, Wiley, Vol. 54, No. 3 ( 2010-03), p. 355-360
    Type of Medium: Online Resource
    ISSN: 1545-5009
    Language: English
    Publisher: Wiley
    Publication Date: 2010
    detail.hit.zdb_id: 2130978-4
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  • 5
    In: Pediatric Blood & Cancer, Wiley, Vol. 60, No. 2 ( 2013-02), p. 258-261
    Type of Medium: Online Resource
    ISSN: 1545-5009
    Language: English
    Publisher: Wiley
    Publication Date: 2013
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  • 6
    In: Cancer, Wiley, Vol. 117, No. 2 ( 2011-01-15), p. 238-249
    Type of Medium: Online Resource
    ISSN: 0008-543X
    URL: Issue
    Language: English
    Publisher: Wiley
    Publication Date: 2011
    detail.hit.zdb_id: 1479932-7
    detail.hit.zdb_id: 1429-1
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  • 7
    Online Resource
    Online Resource
    Informa UK Limited ; 2012
    In:  Pediatric Hematology and Oncology Vol. 29, No. 2 ( 2012-02-24), p. 154-165
    In: Pediatric Hematology and Oncology, Informa UK Limited, Vol. 29, No. 2 ( 2012-02-24), p. 154-165
    Type of Medium: Online Resource
    ISSN: 0888-0018 , 1521-0669
    Language: English
    Publisher: Informa UK Limited
    Publication Date: 2012
    detail.hit.zdb_id: 2001806-X
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  • 8
    In: Blood, American Society of Hematology, Vol. 122, No. 21 ( 2013-11-15), p. 2634-2634
    Abstract: A prospective drug monitoring study was performed to analyse the efficacy of very prolonged use of PEGasparaginase and Erwiniaasparaginase by assessing asparaginase activity, asparagine, glutamine levels and asparaginase antibodies in children with newly diagnosed acute lymphoblastic leukemia (ALL). Patients and Methods Children received 15 PEGasparaginase infusions (2,500 IU/m2 every other week) according to the Dutch Childhood Oncology Group (DCOG)-ALL-10 medium risk intensification protocol after having received native E.coli asparaginase (5,000 IU/m2 every 3 days, 8 doses in total) in the induction course. In case of an allergy to or silent inactivation of PEGasparaginase, Erwinia asparaginase (20,000 IU/m22x-3x per week) was given. All asparaginase preparations were administered intravenously in one hour. Serum asparaginase activity, asparagine, glutamine levels and asparaginase antibodies were measured. Results 89 patients were enrolled in two centers to monitor the PEGasparaginase courses. 62/89 (70%) patients without clinical allergy to and without silent inactivation of PEGasparaginase had serum mean trough activity levels of 899 U/L which were much higher than requested. 20/89 (22%) of the patients showed an allergy and 7/89 (8%) silent inactivation in intensification. All 20 allergic patients (grade 1-4 Common Terminology Criteria Adverse Events) showed PEGasparaginase activity levels of zero. This was not due to the fact that the PEGasparaginase infusion was stopped, as 18 patients showed their allergic reactions at the second dose whereas the serum asparaginase activity level after the first full dose already appeared to be zero in all 18 cases. Moreover, in 4 patients with grade 1 allergy, the second full PEGasparaginase dose was given with pre-treatment of clemastine and hydrocortisone, also resulting in unmeasurable serum activity levels of PEGasparaginase. 59 children from 7 centers with allergy to or silent inactivation of PEGasparaginase who were switched to Erwinia asparaginase were enrolled to monitor the Erwiniaasparaginase courses. Only 2/59 (3%) of the patients developed an allergy to Erwinia asparaginase. No patients with silent inactivation of Erwinia asparaginase were seen. Of the non-allergic Erwinia asparaginase patients, 55/57 (96%) had at least one serum Erwinia asparaginase trough activity level ≥ 100 U/L and 57/57 (100%) ≥ 50 U/L. In 65% and 85% of all samples had serum trough activity levels ≥ 100 U/L and ≥ 50 U/L, respectively. In 33% of patients, the administration frequency could be reduced from 3 times to 2 times per week based upon serum Erwinia asparaginase activity levels ≥ 100 U/L at 72 hours. Serum asparagine level was strongly depleted, but not always completely depleted in Erwinia asparaginase treated patients in contrast to PEGasparaginase. Serum glutamine level was slightly lowered by Erwiniaasparaginase, but no glutamine depletion was observed with both compounds. The presence of serum asparaginase antibodies is related to allergy to and silent inactivation of asparaginase, but predicting asparaginase allergy or silent inactivation is clinically not applicable because of the low specificity, 64% (95%-CI: 43%-82%). Conclusion The use of native E.coli asparaginase in induction leads to 22% allergy and 8% silent inactivation rates of PEGasparaginase in intensification. Therefore, PEGasparaginase should be used upfront already in the induction course instead of native E.coli asparaginase. The dose of PEGasparaginase of 2,500 IU/m2 can be lowered. Switching to Erwinia asparaginase in case of allergy to or silent inactivation of PEGasparaginase leads to effective asparaginase activity levels in the majority of patients. Measuring serum asparaginase activity levels to monitor efficacy of asparaginase is preferred over serum asparagine levels and serum asparaginase antibodies. Therapeutic drug monitoring has now been implemented to individualize PEGasparaginase and Erwinia asparaginase dose and to detect silent inactivation in the current DCOG-ALL-11 protocol. Disclosures: No relevant conflicts of interest to declare.
    Type of Medium: Online Resource
    ISSN: 0006-4971 , 1528-0020
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    Language: English
    Publisher: American Society of Hematology
    Publication Date: 2013
    detail.hit.zdb_id: 1468538-3
    detail.hit.zdb_id: 80069-7
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