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In: The Lancet Haematology, Elsevier BV, Vol. 8, No. 7 ( 2021-07), p. e513-e523

Type of Medium: Online Resource

ISSN: 2352-3026

URL: Article

DOI: 10.1016/S2352-3026(21)00136-8

Language: English

Publisher: Elsevier BV

Publication Date: 2021

In: Blood, American Society of Hematology, Vol. 126, No. 23 ( 2015-12-03), p. 693-693

Abstract: Introduction. Prior studies have described a subset of B-progenitor ALL cases with a distinct gene expression profile and/or deletions involving ERG (encoding the ETS family member v-ets avian erythroblastosis virus E26 oncogene), however the relationship of these alterations and their role in leukemogenesis are poorly understood. We performed integrated genomic and epigenetic analyses, biochemical studies and leukemogenesis assays to define the genetic basis of this form of ALL. Methods. We studied 1674 childhood, adolescent and young adult B-progenitor ALL cases with microarray gene expression profiling and/or RNA-sequencing data to enable the identification of ERG ALL by unsupervised clustering and predictive analysis of microarrays. Detailed genomic analysis was performed for 144 ERG ALL cases, including whole genome (N=38), exome (n=46) and/or RNA-sequencing (n=57) cases, and single nucleotide polymorphism array analysis. Epigenetic profiling, including whole genome bisulfite sequencing, chromatin immunoprecipitation and sequencing for ERG and histone modifications and ATAC-sequencing were performed for a subset of 8 xenografted ERG tumors and reference cell lines. ERG transcript expression was measured by analysis of RNA-seq analysis and quantitative RT-PCR assays, and by interrogation of TCGA and PCGP RNA-seq data. The function of ERG isoforms was evaluated by EMSA and transcriptional reporter assays, immunofluoresence, colony forming assays and retroviral bone marrow transplant assays. Results. One hundred and forty four cases (8.6%) of B-ALL cases exhibited a distinct gene expression profile and lacked known chromosomal rearrangements (ERG ALL). Such cases had favorable outcome. Eighty cases (55.6%) had focal deletions of ERG with no evidence of oncogenic or chimeric ERG fusions. The deletions were most commonly heterozygous and involving exons 3-7 (n=27) or 3-9 (n=22) of 10 coding exons, and less commonly involving exon 1, or a larger region of the gene. No ERG deletions were identified in non-ERG ALL. Two cases harbored missense mutations in the ETS domain. Analysis of whole genome and exome sequencing data of 71 cases identified a high frequency of alterations of lymphoid transcription factors (46.5%; IKZF1 36.7%, PAX5 11.3%); mutation of transcription factors otherwise uncommon in ALL (21%; MYC, MYCBP2, MGA, ZEB2, GATA3); activation of signaling pathways, most commonly NRAS or KRAS (35.2%); cell cycle regulation (22.5%); and epigenetic modifiers (56.3%), most commonly KMT2D, SETD2, ARID2 and NCOR1. Notably, the five year event-free survival of ERG ALL cases with IKZF1 alterations exceeded 85% in both St Jude and Children's Oncology Group cohorts. We observed striking transcriptional deregulation at the ERG locus. Most (51/56) ERG- deleted cases expressed an ERG isoform encoded by a novel exon in intron 6 that splices in frame to distal exons, resulting in expression of a truncated C-terminal ERG protein that lacks the pointed and central regulatory domains, but retains the ETS and transactivation domain (ERGalt). ERGalt was also present in most (36/44) cases lacking an ERG deletion, and was strongly associated with presence of ERGalt protein in leukemic cells. We also identified expression of an Antisense Long non-coding RNA associated with the ERG locus (ALE) in ERG ALL. ERGalt and ALE were absent, or uncommonly expressed at very low levels in non-ERG ALL. ERGalt was absent, and ALE rarely expressed in non-ALL PCGP and TCGA samples. ERGalt and point mutant ERG were retained in the nucleus, bound DNA targets and acted as competitive inhibitors of wild type (WT) ERG in transcriptional reporter assays. Lineage-negative Arf -null bone marrow cells transduced with ERG WT induced an aggressive erythro-megakaryoblastic leukemia; in contrast ERGalt induced an immature lymphoid progenitor leukemia. Conclusions. Genomic alterations drive aberrant transcription of ERG, resulting on expression of a truncated, C-terminal oncogenic ERG protein. This represents a novel mechanism of transcription factor deregulation in leukemia. As a subset of ERG ALL cases lack ERG deletion, and as IKZF1 alterations are not associated with inferior outcome in this form of ALL, diagnostic approaches must incorporate gene expression profiling in addition to identification of ERG and IKZF1 alterations to accurately identify this form of leukemia. Disclosures Evans: Prometheus Labs: Patents & Royalties: Royalties from licensing TPMT genotyping. Stock:Gilead: Membership on an entity's Board of Directors or advisory committees. Voorhees:Oncopeptides: Consultancy; Onyx Pharmaceuticals: Research Funding; GSK: Consultancy; Oncopeptides: Research Funding; Janssen: Research Funding; A Takeda Oncology Company: Consultancy, Research Funding; Celgene: Consultancy; Millennium Pharmaceuticals: Consultancy, Research Funding; Acetylon Pharmaceuticals, Inc.: Research Funding; Novartis: Consultancy; Array BioPharma: Consultancy; GSK: Research Funding; Celgene: Research Funding. Hunger:Spectrum Pharmaceuticals: Consultancy; Jazz Pharmaceuticals: Consultancy; Sigma Tau: Consultancy; Merck: Equity Ownership. Mullighan:Incyte: Consultancy; Amgen: Honoraria.

Type of Medium: Online Resource

ISSN: 0006-4971 , 1528-0020

URL: Article

DOI: 10.1182/blood.V126.23.693.693

Language: English

Publisher: American Society of Hematology

Publication Date: 2015

detail.hit.zdb_id: 1468538-3

detail.hit.zdb_id: 80069-7

In: Blood, American Society of Hematology, Vol. 104, No. 11 ( 2004-11-16), p. 684-684

Abstract: Background: Clofarabine, a next generation nucleoside analogue, was well tolerated and demonstrated activity in adult and pediatric Phase I trials conducted in heavily pretreated leukemia patients. Multicenter Phase II studies in pediatric leukemia have completed accrual in the US and are reported here. Methods: Two Phase 2, multicenter, open-label studies were conducted with clofarabine in children with refractory or relapsed ALL or AML. Clofarabine was administered intravenously over 2 hours at 52 mg/m2/day for 5 consecutive days. Cycles were repeated every 2 to 6 weeks based on response and toxicity. Results: The studies enrolled 100 patients (60 ALL and 40 AML). Currently, data are available for 84 patients (49 ALL, 35 AML). Median age is 12 years (range 1 to 22 years) and median number of prior regimens is 3 (range 1 to 6). Thirty-nine percent had received prior bone marrow transplant (BMT). As determined by independent review, preliminary data indicate overall response rates of 31% in ALL (6 CR, 4 CRp, and 5 PR) and 26% in AML (1 CRp and 8 PR). Median duration of remission for ALL is 9.7 weeks (range 1.0 to 28.6) and for AML is 16.2 weeks (range 1.7 to 56.6+). Thirteen of 24 responding patients (54%) proceeded to BMT. Median survival was 42 weeks (range 7.0 to 63.1+) for responding ALL patients (CR+CRp+PR) and 39 weeks (range 7.7 to 93.6+) for responding AML patients (CRp+PR). Patients who failed treatment or were non-evaluable had shorter median survival; 7.4 weeks (range 0.9 to 40.1+) and 12.4 weeks (range 1.6 to 84.9+) for ALL and AML, respectively. Among the patients who were refractory to the last prior chemotherapy, 7/30 (23%) with ALL and 4/22 (18%) with AML achieved a response with clofarabine. Median duration of remission in these patients is 4.6 weeks (range 2.3 to 24.4+) for ALL and 20 weeks (range 1.7 to 56.6+) for AML. Most drug-related adverse events were transient including febrile neutropenia, diarrhea, nausea/vomiting, fever, skin rash, headache, elevation in liver enzymes and bilirubin, and infusion-related flushing and anxiety. Conclusions: Clofarabine is active as a single agent in pediatric ALL and AML that are refractory to intensive salvage regimens. The overall safety profile is similar to that reported in other pediatric salvage studies. Clofarabine in combination with standard chemotherapy is currently under investigation in children.

Type of Medium: Online Resource

ISSN: 0006-4971 , 1528-0020

URL: Article

DOI: 10.1182/blood.V104.11.684.684

Language: English

Publisher: American Society of Hematology

Publication Date: 2004

detail.hit.zdb_id: 1468538-3

detail.hit.zdb_id: 80069-7

In: Blood, American Society of Hematology, Vol. 116, No. 21 ( 2010-11-19), p. 498-498

Abstract: Abstract 498 Older adolescents and young adults with acute lymphoblastic leukemia (ALL) have historically had a worse prognosis than younger patients. We reviewed the outcome of older adolescents (15 to 18 years old) treated in four consecutive Total Therapy studies to determine if recent improvement in outcome for childhood ALL, achieved with more effective risk-adapted chemotherapy, extend to this high-risk group. Between 1991 and 2007, 963 pediatric patients including 89 older adolescents with newly diagnosed ALL were enrolled in Total Therapy studies XIIIA, XIIIB, XIV and XV. We compared the presenting features and clinical outcomes of the older adolescent group to those of younger patients 1 to 14 years old. In the first three studies, treatment assignment was based on presenting clinical features and genetic abnormalities of the leukemia cells. In Study XV, the level of minimal residual disease (MRD) was used to guide treatment, which featured intensive methotrexate, glucocorticoids, vincristine and asparaginase, 4 courses of high-dose methotrexate (5 g/m2 over 24 hours) as consolidation therapy, and early and extended triple intrathecal therapy for patients with higher-risk ALL. None of the patients received prophylactic cranial irradiation. The 89 older adolescents were significantly more likely to have T-cell ALL, the t(4;11)/MLL-AF4 and detectable MRD during or at the end of remission induction, and less likely to have t(12;21)/ETV6-RUNX1 compared with younger patients. In the first three studies, the 44 older adolescents had a significantly poorer event-free (P=0.0002) and overall (P 〈 0.0001) survival than the 403 younger patients. This gap in prognosis was abolished in Study XV in which 6 of the 45 older adolescents and 28 of 453 younger patients underwent allogeneic transplantation for high-risk presenting features or high level of MRD (≥1%) at the end of 6-week remission induction treatment. Complete remission was achieved in 44 (97.8%) of the older adolescents and 448 (98.9%) of the younger patients (p=0.44). There were 6 treatment failures among adolescents: 1 induction failure, 2 hematological relapses, and 3 toxic deaths during remission. There was no difference in event-free survival between the two age groups (p=0.61): the 5-year rate was 86.4% (95% confidence interval [CI], 72.1 to 93.6) for the 45 older adolescents and 87.4% (95% CI, 83.7 to 90) for the 453 younger patients. The overall survival was also comparable (p=0.13): the 5-year rate was 87.9% (95% CI, 73. 1 to 94.9) vs. 94.1 % (95% CI, 91.4 to 96). The results for older adolescents in Study XV were markedly superior to those attained in the earlier studies (5-year event-free and overall survival rates, both 59.1% [95% CI, 43 to 72] , P=0.006 and P=0.007, respectively). These results demonstrate that it is possible to achieve high cure rate in older adolescents with ALL, at levels similar to the highest ever reported in younger children. The strategy used in this study, based on careful risk assignment, intensive chemotherapy including glucocorticoids, high-dose methotrexate, vincristine, asparaginase and triple intrathecal therapy, but without prophylactic cranial irradiation or routine hematopoietic stem cell transplantation should be tested in young adults with ALL. Disclosures: Jeha: Genzyme: Honoraria, Research Funding. Sandlund: Seattle Genetics: Research Funding. Bhojwani: MedImmune: Research Funding. Relling: St. Jude Children's Research Hospital: Employment, Patents & Royalties; Enzon Pharmaceuticals: Research Funding. Pui: EUSA Pharma: Honoraria; Enzon: Honoraria; Sanofi-Aventis: Honoraria.

Type of Medium: Online Resource

ISSN: 0006-4971 , 1528-0020

URL: Article

DOI: 10.1182/blood.V116.21.498.498

Language: English

Publisher: American Society of Hematology

Publication Date: 2010

detail.hit.zdb_id: 1468538-3

detail.hit.zdb_id: 80069-7

In: Blood, American Society of Hematology, Vol. 116, No. 21 ( 2010-11-19), p. 866-866

Abstract: Abstract 866 Background: Dramatic improvements have been made in treating children with newly diagnosed acute lymphoblastic leukemia (ALL). However, poor outcomes are still observed in patients who are either refractory to or who have relapsed after conventional chemotherapy. Salvage therapy options are urgently needed for this patient population. Clofarabine is approved as a single agent for treatment of pediatric ALL in second relapse. Previously we reported the safety profile and response rates from the phase 1 study assessing clofarabine in combination with etoposide and cyclophosphamide in pediatric patients with refractory/relapsed acute leukemia (Hijiya, Leukemia, 2009). Here we report the phase 2 results. Methods: Patients (pts) aged 1–21 years with refractory/relapsed ALL were treated at the recommended phase 2 dose of clofarabine 40 mg/m2/day, cyclophosphamide 440 mg/m2/day, and etoposide 100 mg/m2/day. All 3 agents were given IV daily for 5 consecutive days in induction and 4 consecutive days in consolidation. Patients could receive up to 2 induction cycles, followed by consolidation (max 8 cycles including induction). The primary endpoint was overall remission rate (ORR: complete remission [CR] and CR without platelet recovery [CRp] ). Secondary endpoints were safety and tolerability, rate of partial remission (PR), duration of remission (DOR), event-free survival (EFS), 4-month EFS, and overall survival (OS). Minimal residual disease (MRD) by flow cytometry was evaluated as an exploratory endpoint. Results: Phase 2 comprised 25 pts (median follow-up 10.7 weeks [wks]): 16 males and 9 females with a median age of 14.0 years. Twenty-one pts had pre-B cell ALL, 1 pt had T cell ALL and 3 pts had an unknown immunophenotype. Fourteen pts had 2 prior induction regimens, 7 pts had 3 prior induction regimens and 4 pts had 1 prior induction regimen. Fifteen pts (60%) were refractory to their immediately preceding regimen. Four pts had received a prior hematopoietic stem cell transplant (HSCT). The investigator-assessed ORR was 44%; 7 CR (28%) and 4 CRp (16%). Additionally, 3 pts (12%) achieved PR. Eight pts were evaluable for MRD after induction, 5 were MRD negative (defined as 〈 0.01%) and 3 were positive. Overall, 10 pts proceeded to HSCT, including 7 of 11 responders (CR + CRp). The median DOR at the last known follow-up (not censored for alternative therapy) was 15.9 wks (range: 2.9–109.6+) for pts with CR, but was not estimable for pts with CRp (range: 30.1+-67.7+). Median DOR for responders censored at alternative therapy/HSCT was not estimable as most pts received alternate therapy or transplant prior to event occurrence (range: 0.1+-10.9+ wks). Median OS censored at the last known follow-up was 10.7 wks for all patients (range: 1.0–113.1+) and 80.9 wks for responders (range: 8.1–113.1+). The median EFS for responders was 73.9 wks and 44% of all 25 pts were free of events at 4 months. The median cumulative number of clofarabine cycles received was 1 (range: 1–3), with most pts (10 of 11 responders) achieving best response after 1 cycle. The treatment-related non-hematologic adverse events (AEs) occurring in ≥25% of phase 2 pts were vomiting (88%); nausea (72%); febrile neutropenia (60%), pyrexia (52%); decreased appetite (44%); ALT increased, AST increased, hypokalemia, and hypotension (36% each), diarrhea and hyperbilirubinemia (28% each). One pt discontinued study treatment due to treatment-related fungal sinusitis which occurred 17 days after the last dose of study drug. Serious treatment-related AEs, were reported in 84% of pts. Six pts (24%) died within 30 days of receiving last dose of study treatment. Deaths were due to hepatic veno-occlusive disease (2 pts), septic shock (2 pts), pulmonary edema (1 pt) and infection (1 pt). As reported previously, after 4 of the initial 8 pts developed severe hepatotoxicity, the protocol was amended to exclude pts with prior HSCT, viral hepatitis cirrhosis, or elevated conjugated bilirubin levels at study entry (Hijiya, ASH 2008). There were no additional events of severe hepatotoxicity observed in the remaining 17 pts. Conclusions: Combination treatment with clofarabine, etoposide and cyclophosphamide in pediatric pts with refractory or relapsed ALL resulted in an ORR of 44% and negative MRD in heavily treated pts. Ten pts including 7 of 11 responders proceeded to HSCT. The safety profile is acceptable in this relapsed/refractory population. Disclosures: Hijiya: Genzyme: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Off Label Use: Clofarabine (Clolar) is approved by the US FDA for the treatment of pediatric patients 1 to 21 years old with relapsed or refractory acute lymphoblastic leukemia after at least two prior regimens. This trial examines the use of clofarabine in combination with etoposide and cyclophosphamide. Paul:Genzyme: Employment, Equity Ownership. Borowitz:genzyme: Research Funding; becton-dickinson: Research Funding; Alexion: Consultancy; beckman-coulter: Research Funding. Isakoff:Genzyme: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau. Silverman:Genzyme: Research Funding; Enzon : Honoraria, Membership on an entity's Board of Directors or advisory committees; EUSA: Honoraria, Membership on an entity's Board of Directors or advisory committees. Steinherz:Genzyme: Research Funding. Kadota:Genzyme: Employment, Equity Ownership. Pressey:Genzyme: Research Funding. Shen:Genzyme: Research Funding. Chu:Genzyme: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Cooper:Genzyme: Research Funding. Jeha:Genzyme: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Razzouk:Genzyme: Research Funding. Rytting:Genzyme: Research Funding. Barry:Genzyme: Employment, Equity Ownership. Carroll:Genzyme: Research Funding. Gaynon:Genzyme: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding.

Type of Medium: Online Resource

ISSN: 0006-4971 , 1528-0020

URL: Article

DOI: 10.1182/blood.V116.21.866.866

Language: English

Publisher: American Society of Hematology

Publication Date: 2010

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detail.hit.zdb_id: 80069-7

In: Blood, American Society of Hematology, Vol. 120, No. 21 ( 2012-11-16), p. 2568-2568

Abstract: Abstract 2568 Background: L-asparaginase (L-ASP) is an important component of multi-agent chemotherapy for treatment of Acute Lymphoblastic Leukemia (ALL) in children and young adults. The pegylated E. coli derived form, Oncaspar® (PEG-ASP), is most commonly used because of its longer half-life and lower immunogenicity compared to the native enzyme; however, clinical hypersensitivity reactions still occurs in 10–30% of patients (pts) requiring its discontinuation. Asparaginase Erwinia Chrysanthemi (Erwinaze™) is an L-ASP derived from a different bacterium and is immunologically distinct from the E. coli L-ASP. We conducted a compassionate use trial of Erwinaze in pts with ALL and hypersensitivity to native E. coli or PEG-ASP to collect safety information. Patients and Methods: Pts of any age with ALL or lymphoblastic lymphoma (LBL) who developed a Grade ≥2 clinical hypersensitivity reaction to PEG-ASP or native E. coli ASP (Elspar®) were eligible. Pts with a history of pancreatitis, previous allergic reaction to Erwinaze, or pregnant, were excluded. The study was IRB approved at each institution and pts/family provided informed consent/assent. Safety information on Erwinaze-related adverse events (AEs) were captured on Case Report Forms (CRFs) submitted to the Sponsor when the pt completed his/her entire Erwinaze treatment plan. AEs may have also been reported directly by the investigational sites. Results: Between February 2006 and November 2011, 1,368 pts were treated with Erwinaze. CRFs were received in 893 pts and 47 additional AEs were received from patients for which a CRF was not obtained. The average age was 9.6 years (range 1–66). The majority of patients (63.5%) were male. Of the pts for which CRFs were received (893); 77.6% were able to conclude their Erwinaze treatment. Discontinuation was due to allergic reaction in 8.8%; other AEs 4.7%; at the physician or patient discretion 7.5%; and missing information in 1.3%. Anaphylaxis was reported in 8 pts (0.9%) and Grade ≥2 clinical hypersensitivity reactions in 130 (13.8%). The incidence of pancreatitis was 3.9%, hemorrhagic or thrombosis abnormalities 2.4%, hyperglycemia 3.6% and elevation in liver enzymes 3.5%. There were 18 deaths on study; 11 disease progression, 3 intracranial hemorrhage, 4 other individual reports. Conclusion: This is the largest study of pts treated with Erwinaze to determine the toxicity profile. Erwinaze was well tolerated with no unexpected toxicities identified beyond those associated with L-Asp treatment. This compassionate use trial permitted the continuation and completion of asparaginase treatment in 77.6% of pts with hypersensitivity reactions to E. coli formulations. Final results will be available for presentation. Disclosures: Plourde: Jazz Pharmaceuticals: Employment, Equity Ownership. Mercedes:Jazz Pharmaceuticals: Employment. Corn:EUSA Pharma: Employment.

Type of Medium: Online Resource

ISSN: 0006-4971 , 1528-0020

URL: Article

DOI: 10.1182/blood.V120.21.2568.2568

Language: English

Publisher: American Society of Hematology

Publication Date: 2012

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detail.hit.zdb_id: 80069-7

In: Blood, American Society of Hematology, Vol. 103, No. 3 ( 2004-02-01), p. 784-789

Abstract: Despite progress in leukemia therapy, most children who experience relapse have a dismal prognosis. New, effective approaches are needed. We conducted a phase 1 study of a novel nucleoside analog, clofarabine, in pediatric patients with refractory and relapsed leukemia. Clofarabine was infused intravenously over 1 hour each day for 5 days. Six dose levels, between 11.25 and 70 mg/m2 per day for 5 days, were studied in 25 patients. A modified 3 + 3 phase 1 design was followed with 30% dose escalation until the dose-limiting toxicity (DLT) was defined. The maximum tolerated dose (MTD) was 52 mg/m2 per day for 5 days. At the end of infusion at MTD, clofarabine triphosphate levels in leukemia blasts varied between 6 μM and 19 μM, which resulted in complete and sustained inhibition of DNA synthesis. The DLT was reversible hepatotoxicity and skin rash at 70 mg/m2 per day for 5 days. Twenty-five patients were treated. Five patients achieved complete remission (CR), and 3 achieved partial remission (PR), for an overall response rate of 32%. Clofarabine is well tolerated and shows significant antileukemic activity in heavily pretreated children. Multicenter phase 2 trials in pediatric acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML) are ongoing.

Type of Medium: Online Resource

ISSN: 0006-4971 , 1528-0020

URL: Article

DOI: 10.1182/blood-2003-06-2122

Language: English

Publisher: American Society of Hematology

Publication Date: 2004

detail.hit.zdb_id: 1468538-3

detail.hit.zdb_id: 80069-7

In: Blood, American Society of Hematology, Vol. 126, No. 23 ( 2015-12-03), p. 4981-4981

Abstract: Background: Successful outcome in childhood acute lymphoblastic leukemia (ALL) relies upon appropriate central nervous system (CNS)-directed therapy for treatment of subclinical or overt CNS leukemia. Patients with leukemia blasts detected in the cerebrospinal fluid (CSF) at diagnosis have poorer survival compared with patients without blasts in the CSF and require intensified intrathecal therapy to avert a higher rate of relapse. Traditionally, CSF assessment is performed by morphological analysis of CSF smears and the blasts confirmed by immunohistochemistry or flow cytometry. The confirmation tests are done at few institutions and rely on subjective operator judgment for identification of leukemic blasts. A precise definition of CNS involvement is necessary to avoid over- or under- treatment. Next-generation sequencing (NGS) is currently being used for minimal residual disease (MRD) assessment in lymphoid malignancies (Faham et al., Blood 2012). In this study, we assessed whether the NGS method could be used to detect leukemic clonotypes in CSF samples from 89 newly diagnosed pediatric ALL patients. Methods: Diagnostic bone marrow samples and paired CSF samples were obtained from 89 patients. CSF samples were collected in one tube and fractionated for Wright stained cytospins (1ml), TdT immunohistochemistry (1ml), and the remainder (3-5ml) for NGS-based MRD studies (Adaptive Biotechnologies, South San Francisco, CA). Briefly, using universal primer sets, we amplified variable, diversity, and joining gene segments from immunoglobulin (Ig) heavy chain (IGH), Ig kappa chain (IGK), and T-cell receptor beta (TRB), delta (TRD) and gamma (TRG) loci from genomic DNA. Amplified products were sequenced and analyzed using standardized algorithms for clonotype determination. Tumor-specific clonotypes were identified for each patient based on their high-frequency within the B-cell repertoire. The presence of the tumor-specific clonotype was then quantitated in CSF (cell pellet and supernatant) samples obtained at diagnosis. A quantitative and standardized measure of leukemic clonotype level per million leukocytes in each follow-up sample was determined. Results: Diagnostic bone marrow samples from 89 pediatric ALL patients were used to identify the tumor-specific clonotypes. At least one tumor-specific clonotype was identified in 86/89 (97%) of the patients. The IGH-VDJ assay was the most frequent gene rearrangement: at least one IGH-VDJ clonal rearrangement was detected in 66 of the diagnostic ALL samples. TRD was the second most informative receptor with a clonal rearrangement found in 43 patients, followed by TRG in 38 patients, IGK in 31 patients, TCB in 16 patients and IGH-DJ in 13 patients. The level of tumor burden associated with each leukemic clonotype was then assessed in CSF samples drawn at diagnosis from each of the 86 patients. All 40 CNS1 patients had no detectable or minimal ( 〈 10) leukemic cell equivalents. Of the 24 patients with CNS2 but TDT negative status, only 2 had 〉 10 leukemic cell equivalents in the CSF. By contrast, 8 of 20 (40%) patients with CNS2 and TDT positive status and both patients with CNS3 had CSF with 〉 10 leukemic cell equivalents (Figure 1). Conclusions: This study demonstrates that the NGS-based method can be used to assess CNS involvement in pediatric patients with ALL. Based on these results, NGS-based CNS assessment will be used for patient stratification in future clinical trials for pediatric ALL. Figure 1. Figure 1. Disclosures Zheng: Adaptive Biotechnologies Corp.: Employment, Equity Ownership. Carlton:Adaptive Biotechnologies Corp.: Employment, Equity Ownership. Faham:Adaptive Biotechnologies Corp.: Employment, Other: Stockholder.

Type of Medium: Online Resource

ISSN: 0006-4971 , 1528-0020

URL: Article

DOI: 10.1182/blood.V126.23.4981.4981

Language: English

Publisher: American Society of Hematology

Publication Date: 2015

detail.hit.zdb_id: 1468538-3

detail.hit.zdb_id: 80069-7

In: Blood, American Society of Hematology, Vol. 124, No. 21 ( 2014-12-06), p. 2295-2295

Abstract: In order to study interventions that influence the severity of symptoms and serum asparaginase activity following asparaginase-induced hypersensitivity reactions, we developed a murine model of asparaginase allergy that recapitulates key features of clinical hypersensitivity to native E. coli asparaginase. BALB/c mice received 10 μg ip doses of E. coli asparaginase formulated with aluminum hydroxide adjuvant on day 0 and 14 of treatment in order to sensitize mice to asparaginase. Asparaginase allergies were induced in sensitized mice by challenging with a 100 μg iv dose of E. coli asparaginase on day 24 of treatment. The severity of hypersensitivity was reflected by the decrease in rectal temperature following the asparaginase challenge. Pre-challenge plasma samples were collected for anti-asparaginase antibody levels before inducing asparaginase allergies, and post-challenge samples were collected at the end of the experiment for measuring anti-asparaginase antibody levels, asparaginase activity, and mouse mast cell protease 1 (mMCP-1) levels. Sensitized mice developed high levels of anti-asparaginase IgG antibodies (P = 1.1 x 10-7) and had immediate hypersensitivity reactions (P = 3.3 x 10-10) to asparaginase upon challenge compared to non-sensitized mice. Furthermore, sensitized mice had profoundly lower plasma asparaginase activity (P = 4.2 x 10-13) and elevated levels of mouse mast cell protease 1 (mMCP-1, P = 6.1 x 10-3) after the asparaginase challenge compared to non-sensitized mice. We investigated the influence of pretreatment with the H1 receptor antagonist triprolidine, the H2 receptor antagonist cimetidine, the PAF receptor antagonist CV-6209, or dexamethasone on the severity of asparaginase-induced allergies. Our studies showed that the combination of triprolidine and CV-6209 was best for mitigating asparaginase-induced hypersensitivity symptoms (i.e., temperature drop) compared to non-pretreated, sensitized mice (P = 1.2 x 10-5). However, pretreatment with oral dexamethasone (4 mg/L in drinking water starting 7 days before asparaginase sensitization) was the only agent capable of mitigating the severity of the hypersensitivity symptoms (P = 0.03) and also partially restoring asparaginase activity (P = 8.3 x 10-4) compared to sensitized mice. Dose adjustment strategies were investigated for rescuing asparaginase activity in sensitized mice without requiring pretreatment with dexamethasone, and a 5-fold greater dose of asparaginase was required to restore enzyme activity to a similar concentration as in non-sensitized mice. In the absence of pretreatment, we found that the severity of asparaginase-induced reactions increased in a dose-dependent manner and that mMCP-1 levels correlated to the severity of the reactions (R2 = 0.577, P = 3.0 x 10-16). Our results suggest a role of histamine and PAF in asparaginase-induced allergies and demonstrate possible strategies for mitigating the severity of asparaginase-induced reactions and maintaining targeted concentrations of asparaginase. Furthermore, our results indicate that mast cell-derived proteases released during allergic reactions to asparaginase may be a useful marker of hypersensitivity, as elevated levels of mMCP-1 were detected in all sensitized mice and correlated with the severity of the reaction. Disclosures Evans: St. Jude: In accordance with institutional policy (St. Jude), I and/or my spouse have in the past received a portion of the income St. Jude receives from licensing patent rights related to TPMT polymorphisms as clinical diagnostics. Patents & Royalties. Relling:St. Jude: In accordance with institutional policy (St. Jude), I and/or my spouse have in the past received a portion of the income St. Jude receives from licensing patent rights related to TPMT polymorphisms as clinical diagnostics. Patents & Royalties.

Type of Medium: Online Resource

ISSN: 0006-4971 , 1528-0020

URL: Article

DOI: 10.1182/blood.V124.21.2295.2295

Language: English

Publisher: American Society of Hematology

Publication Date: 2014

detail.hit.zdb_id: 1468538-3

detail.hit.zdb_id: 80069-7

In: Blood, American Society of Hematology, Vol. 96, No. 10 ( 2000-11-15), p. 3647-3649

Abstract: Leukemia is observed with increased frequency in patients with severe congenital neutropenia (SCN). In the past decade, recombinant human granulocyte colony-stimulating factor (rh G-CSF) has prolonged the survival of patients with SCN increasingly reported to have leukemias. In this communication acute myelogenous leukemia (AML) associated with a mutation of the G-CSF receptor (G-CSF-R) developed in a patient with SCN maintained on long-term G-CSF therapy. The blast count in the blood and bone marrow fell to undetectable levels twice on withholding G-CSF and without chemotherapy administration, but the mutant G-CSF-R was detectable during this period. The patient subsequently underwent successful allogeneic bone marrow transplantation. After transplantation, the patient's neutrophil elastase (ELA-2) mutation and G-CSF-R mutation became undetectable by polymerase chain reaction. This report provides novel insights on leukemia developing in congenital neutropenia.

Type of Medium: Online Resource

ISSN: 1528-0020 , 0006-4971

URL: Article

DOI: 10.1182/blood.V96.10.3647.h8003647_3647_3649

Language: English

Publisher: American Society of Hematology

Publication Date: 2000

detail.hit.zdb_id: 1468538-3

detail.hit.zdb_id: 80069-7