How I Treat Philadelphia Chromosome-like Acute Lymphoblastic Leukemia in Children, Adolescents, and Young Adults

Philadelphia chromosome-like acute lymphoblastic leukemia (Ph-like ALL) represents a high-risk B-lineage ALL subtype characterized by adverse clinical features and poor relapse-free survival despite risk-adapted multi-agent chemotherapy regimens. The advent of next-generation sequencing has unraveled the diversity of kinase-activating genetic drivers in Ph-like ALL that are potentially amenable to 'personalized' molecularly-targeted therapies. Based upon robust preclinical data and promising case series of clinical activity of tyrosine kinase inhibitor (TKI)-based treatment in adults and children with relevant genetic Ph-like ALL subtypes, several clinical trials have investigated the efficacy of JAK- or ABL-directed TKIs in CRLF2/JAK pathway-mutant or ABL-class Ph-like ALL, respectively. Final results of these trials are pending, and standard-of-care therapeutic approaches for patients with Ph-like ALL have yet to be defined. In this How I Treat perspective, we review recent literature to guide current evidence-based treatment recommendations via illustrative clinical vignettes of children, adolescents, and young adults with newly-diagnosed or relapsed/refractory Ph-like ALL, and we further highlight open and soon-to-open trials investigating immunotherapy and TKIs specifically for this high-risk patient population.

Risk factors and clinical impact of thrombosis during induction chemotherapy for pediatric acute lymphoblastic leukemia: A report from CYP-C

Thromboembolism (TE) is associated with reduced survival in pediatric acute lymphoblastic leukemia (ALL). It has been hypothesized that TE might signal leukemic aggressiveness. The objective was to determine risk factors for TE during ALL induction (TEind ) therapy and whether TEind is associated with treatment refractoriness. This retrospective cohort study using the population-based Cancer in Young People Canada (CYP-C) registry included children <15 years of age diagnosed with ALL (2000-2019) and treated at one of 12 Canadian pediatric centers outside of Ontario. Univariate and multivariable logistic regression models were used to determine risk factors for TEind and whether TEind predicted induction failure and ALL treatment intensification. The impact of TEind on overall and event-free survival was estimated using Cox proportional hazard regression models. The study included 2589 children, of which 45 (1.7%) developed a TEind . Age (<1 year and ≥10 years vs. 1-<10 years), T-cell phenotype, high-risk ALL, and central nervous system involvement were all associated with TEind in univariate analysis. Age and T-cell phenotype remained independent predictors of TEind in multivariable analysis. Induction failure occurred in 53 patients (2.1%). TEind was not associated with induction failure (OR: not estimable) or treatment intensification (adjusted OR [95% CI]: 0.66 [0.26-1.69]). TEind was independently associated with overall survival (adjusted HR [95% CI]: 2.54 [1.20-5.03]) but not event-free survival (adjusted HR [95% CI] 1.86 [0.98-3.51]). In this population-based study of children treated with contemporary chemotherapy protocols, TEind was associated with age and T-cell phenotype and mortality but did not predict induction failure.

Access to innovative therapies in pediatric oncology: Report of the nationwide experience in Canada

BACKGROUND

The need for new therapies to improve survival and outcomes in pediatric oncology along with the lack of approval and accessible clinical trials has led to "out-of-trial" use of innovative therapies. We conducted a retrospective analysis of requests for innovative anticancer therapy in Canadian pediatric oncology tertiary centers for patients less than 30 years old between 2013 and 2020.

METHODS

Innovative therapies were defined as cancer-directed drugs used (a) off-label, (b) unlicensed drugs being used outside the context of a clinical trial, or (c) approved drugs with limited evidence in pediatrics. We excluded cytotoxic chemotherapy, cellular products, and cytokines.

RESULTS

We retrieved data on 352 innovative therapy drug requests. Underlying diagnosis was primary CNS tumor 31%; extracranial solid tumor 37%, leukemia/lymphoma 22%, LCH 2%, and plexiform neurofibroma 6%. RAS/MAP kinase pathway inhibitors were the most frequently requested innovative therapies in 28% of all requests followed by multi-targeted tyrosine kinase inhibitors (17%), inhibitors of the PIK3CA-mTOR-AKT pathway (8%), immune checkpoints inhibitors (8%), and antibody drug conjugates (8%). In 112 out of 352 requests, innovative therapies were used in combination with another anticancer agent. 48% of requests were motivated by the presence of an actionable molecular target. Compassionate access accounted for 52% of all requests while public insurance was used in 27%. Mechanisms of funding varied between provinces.

CONCLUSION

This real-world data collection illustrates an increasing use of "out-of-trial" innovative therapies in pediatric oncology. This new field of practice warrants further studies to understand the impact on patient trajectory and equity in access to innovative therapies.

CBFA2T3::GLIS2 pediatric acute megakaryoblastic leukemia is sensitive to BCL-XL inhibition by navitoclax and DT2216

ABSTRACT

Acute megakaryoblastic leukemia (AMKL) is a rare, developmentally restricted, and highly lethal cancer of early childhood. The paucity and hypocellularity (due to myelofibrosis) of primary patient samples hamper the discovery of cell- and genotype-specific treatments. AMKL is driven by mutually exclusive chimeric fusion oncogenes in two-thirds of the cases, with CBFA2T3::GLIS2 (CG2) and NUP98 fusions (NUP98r) representing the highest-fatality subgroups. We established CD34+ cord blood-derived CG2 models (n = 6) that sustain serial transplantation and recapitulate human leukemia regarding immunophenotype, leukemia-initiating cell frequencies, comutational landscape, and gene expression signature, with distinct upregulation of the prosurvival factor B-cell lymphoma 2 (BCL2). Cell membrane proteomic analyses highlighted CG2 surface markers preferentially expressed on leukemic cells compared with CD34+ cells (eg, NCAM1 and CD151). AMKL differentiation block in the mega-erythroid progenitor space was confirmed by single-cell profiling. Although CG2 cells were rather resistant to BCL2 genetic knockdown or selective pharmacological inhibition with venetoclax, they were vulnerable to strategies that target the megakaryocytic prosurvival factor BCL-XL (BCL2L1), including in vitro and in vivo treatment with BCL2/BCL-XL/BCL-W inhibitor navitoclax and DT2216, a selective BCL-XL proteolysis-targeting chimera degrader developed to limit thrombocytopenia in patients. NUP98r AMKL were also sensitive to BCL-XL inhibition but not the NUP98r monocytic leukemia, pointing to a lineage-specific dependency. Navitoclax or DT2216 treatment in combination with low-dose cytarabine further reduced leukemic burden in mice. This work extends the cellular and molecular diversity set of human AMKL models and uncovers BCL-XL as a therapeutic vulnerability in CG2 and NUP98r AMKL.

COVID-19 outcomes in patients with sickle cell disease and sickle cell trait compared with individuals without sickle cell disease or trait: a systematic review and meta-analysis

Background

Clinical manifestations and severity of SARS-CoV-2 infection in individuals with sickle cell disease (SCD) and sickle cell trait (SCT) are not well understood yet.

Methods

We performed a systematic review and meta-analysis to assess COVID-19 outcomes in individuals with SCD or SCT compared to individuals without sickle cell disease or trait. An electronic search on PubMed, Embase, and Cochrane Library was performed on August 3, 2023. Two authors (IFM and ISP) independently screened (IFM and ISP) and extracted data (IFM and ILC) from included studies. Main exclusion criterion was the absence of the non-SCD/SCT group. Exposure effects for binary endpoints were compared using pooled odds ratio (OR) with 95% confidence intervals (CI). I2 statistics was used to assess the heterogeneity and DerSimonian and Laird random-effects models were applied for all analyses to minimize the impact of differences in methods and outcomes definitions between studies. The overall quality of evidence was assessed using the GRADE system. Review Manager 5.4 and R software (v4.2.2) were used for statistical analyses. Registered with PROSPERO, CRD42022366015.

Findings

Overall, 22 studies were included, with a total of 1892 individuals with SCD, 8677 individuals with SCT, and 1,653,369 individuals without SCD/SCT. No difference in all-cause mortality was seen between SCD/SCT and non-SCD/SCT (OR 1.18; 95% CI 0.78-1.77; p = 0.429; I2 = 82%). When considering only studies adjusted for confounders (8 studies), patients with SCD/SCT were shown to be at increased risk of death (OR 1.86; 95% CI 1.30-2.66; p = 0.0007; I2 = 34%). No significant difference was seen between individuals with SCD and SCT (p = 0.863). The adjusted for confounders analysis for hospitalisation revealed higher rates for the SCD (OR 5.44; 95% CI 1.55-19.13; p = 0.008; I2 = 97%) and the SCT groups (OR 1.31; 95% CI 1.10-1.55; p = 0.002; I2 = 0) compared to the non-SCD/SCT population. Moreover, it was significantly higher for the SCD group (test for subgroup difference; p = 0.028).

Interpretation

Our findings suggest that patients with SCD or SCT may present with a higher mortality and hospitalisation rates due to COVID-19 infection.

Funding

None.

Disparities in parental distress in a multicenter clinical trial for pediatric acute lymphoblastic leukemia

BACKGROUND

Parent psychological distress during childhood cancer treatment has short- and long-term implications for parent, child, and family well-being. Identifying targetable predictors of parental distress is essential to inform interventions. We investigated the association between household material hardship (HMH), a modifiable poverty-exposure defined as housing, food, or utility insecurity, and severe psychological distress among parents of children aged 1-17 years with acute lymphoblastic leukemia (ALL) enrolled on the multicenter Dana-Farber ALL Consortium Trial 16-001.

METHODS

This was a secondary analysis of parent-reported data. Parents completed an HMH survey within 32 days of clinical trial enrollment (T0) and again at 6 months into therapy (T1). The primary exposure was HMH at T0 and primary outcome was severe parental distress at T0 and T1, defined as a score greater than or equal to 13 on the Kessler-6 Psychological Distress Scale. Multivariable models were adjusted for ALL risk group and single parent status.

RESULTS

Among 375 evaluable parents, one-third (32%; n = 120/375) reported HMH at T0. In multivariable analyses, T0 HMH was associated with over twice the odds of severe psychological distress at T0 and T1 HMH was associated with over 5 times the odds of severe distress at T1.

CONCLUSIONS

Despite uniform clinical trial treatment of their children at well-resourced pediatric centers, HMH-exposed parents-compared with unexposed parents-experienced statistically significantly increased odds of severe psychological distress at the time of their child's leukemia diagnosis, which worsened 6 months into therapy. These data identify a high-risk parental population who may benefit from early psychosocial and HMH-targeted interventions to mitigate disparities in well-being.

Outlier Expression of Isoforms by Targeted or Total RNA Sequencing Identifies Clinically Significant Genomic Variants in Hematolymphoid Tumors

Recognition of aberrant gene isoforms due to DNA events can impact risk stratification and molecular classification of hematolymphoid tumors. In myelodysplastic syndromes, KMT2A partial tandem duplication (PTD) was one of the top adverse predictors in the International Prognostic Scoring System-Molecular study. In B-cell acute lymphoblastic leukemia (B-ALL), ERG isoforms have been proposed as markers of favorable-risk DUX4 rearrangements, whereas deletion-mediated IKZF1 isoforms are associated with adverse prognosis and have been extended to the high-risk IKZF1plus signature defined by codeletions, including PAX5. In this limited study, outlier expression of isoforms as markers of IKZF1 intragenic or 3' deletions, DUX4 rearrangements, or PAX5 intragenic deletions were 92.3% (48/52), 90% (9/10), or 100% (9/9) sensitive, respectively, and 98.7% (368/373), 100% (35/35), or 97.1% (102/105) specific, respectively, by targeted RNA sequencing, and 84.0% (21/25), 85.7% (6/7), or 81.8% (9/11) sensitive, respectively, and 98.2% (109/111), 98.4% (127/129), or 98.7% (78/79) specific, respectively, by total RNA sequencing. Comprehensive split-read analysis identified expressed DNA breakpoints, cryptic splice sites associated with IKZF1 3' deletions, PTD of IKZF1 exon 5 spanning N159Y in B-ALL with mutated IKZF1 N159Y, and truncated KMT2A-PTD isoforms. Outlier isoforms were also effective targeted RNA markers for PAX5 intragenic amplifications (B-ALL), KMT2A-PTD (myeloid malignant cancers), and rare NOTCH1 intragenic deletions (T-cell acute lymphoblastic leukemia). These findings support the use of outlier isoform analysis as a robust strategy for detecting clinically significant DNA events.

Dasatinib with intensive chemotherapy in de novo paediatric Philadelphia chromosome-positive acute lymphoblastic leukaemia (CA180-372/COG AALL1122): a single-arm, multicentre, phase 2 trial

BACKGROUND

The outcome of children with Philadelphia chromosome-positive (Ph-positive) acute lymphoblastic leukaemia significantly improved with the combination of imatinib and intensive chemotherapy. We aimed to investigate the efficacy of dasatinib, a second-generation ABL-class inhibitor, with intensive chemotherapy in children with newly diagnosed Ph-positive acute lymphoblastic leukaemia.

METHODS

CA180-372/COG AALL1122 was a joint Children's Oncology Group (COG) and European intergroup study of post-induction treatment of Ph-positive acute lymphoblastic leukaemia (EsPhALL) open-label, single-arm, phase 2 study. Eligible patients (aged >1 year to <18 years) with newly diagnosed Ph-positive acute lymphoblastic leukaemia and performance status of at least 60% received EsPhALL chemotherapy plus dasatinib 60 mg/m² orally once daily from day 15 of induction. Patients with minimal residual disease of at least 0·05% after induction 1B or who were positive for minimal residual disease after the three consolidation blocks were classified as high risk and allocated to receive haematopoietic stem-cell transplantation (HSCT) in first complete remission. The remaining patients were considered standard risk and received chemotherapy plus dasatinib for 2 years. The primary endpoint was the 3-year event-free survival of dasatinib plus chemotherapy compared with external historical controls. The trial was considered positive if one of the following conditions was met: superiority over chemotherapy alone in the AIEOP-BFM 2000 high-risk group; or non-inferiority (with a margin of -5%) or superiority to imatinib plus chemotherapy in the EsPhALL 2010 cohort. All participants who received at least one dose of dasatinib were included in the safety and efficacy analyses. This trial was registered with ClinicalTrials.gov, NCT01460160, and recruitment is closed.

FINDINGS

Between March 13, 2012, and May 27, 2014, 109 patients were enrolled at 69 sites (including 51 COG sites in the USA, Canada, and Australia, and 18 EsPhALL sites in Italy and the UK). Three patients were ineligible and did not receive dasatinib. 106 patients were treated and included in analyses (49 [46%] female and 57 [54%] male; 85 [80%] White, 13 [12%] Black or African American, five [5%] Asian, and three [3%] other races; 24 [23%] Hispanic or Latino ethnicity). All 106 treated patients reached complete remission; 87 (82%) were classified as standard risk and 19 (18%) met HSCT criteria and were classified as high risk, but only 15 (14%) received HSCT in first complete remission. The 3-year event-free survival of dasatinib plus chemotherapy was superior to chemotherapy alone (65·5% [90% Clopper-Pearson CI 57·7 to 73·7] vs 49·2% [38·0 to 60·4]; p=0·032), and was non-inferior to imatinib plus chemotherapy (59·1% [51·8 to 66·2], 90% CI of the treatment difference: -3·3 to 17·2), but not superior to imatinib plus chemotherapy (65·5% vs 59·1%; p=0·27). The most frequent grade 3-5 adverse events were febrile neutropenia (n=93) and bacteraemia (n=21). Nine remission deaths occurred, which were due to infections (n=5), transplantation-related (n=2), due to cardiac arrest (n=1), or had an unknown cause (n=1). No dasatinib-related deaths occurred.

INTERPRETATION

Dasatinib plus EsPhALL chemotherapy is safe and active in paediatric Ph-positive acute lymphoblastic leukaemia. 3-year event-free survival was similar to that of previous Ph-positive acute lymphoblastic leukaemia trials despite the limited use of HSCT in first complete remission.

FUNDING

Bristol Myers Squibb.

IL16 and factor V gene variations are associated with asparaginase-related thrombosis in childhood acute lymphoblastic leukemia patients

Aim: We previously conducted exome-wide association study in acute lymphoblastic leukemia patients and identified association of five SNPs with asparaginase-related thrombosis. Here we aimed to replicate these findings in an independent patient cohort and through analyses in vitro. Patients & methods: SNPs located in IL16, MYBBP1A, PKD2L1, RIN3 and MPEG1 genes were analyzed in patients receiving Dana-Farber Cancer Institute acute lymphoblastic leukemia treatment protocols 05-001 and 11-001. Thrombophilia-related variations were also analysed. Results: IL16 rs11556218 conferred higher risk of thrombosis and higher in vitro sensitivity to asparaginase. The association was modulated by the treatment protocol, risk group and immunophenotype. A crosstalk between factor V Leiden, non-O blood groups and higher risk of thrombosis was also seen. Conclusion: IL16 and factor V Leiden variations are implicated in asparaginase-related thrombosis.

A systems approach points to a therapeutic role for retinoids in asparaginase-associated pancreatitis

Among drug-induced adverse events, pancreatitis is life-threatening and results in substantial morbidity. A prototype example is the pancreatitis caused by asparaginase, a crucial drug used to treat acute lymphoblastic leukemia (ALL). Here, we used a systems approach to identify the factors affecting asparaginase-associated pancreatitis (AAP). Connectivity Map analysis of the transcriptomic data showed that asparaginase-induced gene signatures were potentially reversed by retinoids (vitamin A and its analogs). Analysis of a large electronic health record database (TriNetX) and the U.S. Federal Drug Administration Adverse Events Reporting System demonstrated a reduction in AAP risk with concomitant exposure to vitamin A. Furthermore, we performed a global metabolomic screening of plasma samples from 24 individuals with ALL who developed pancreatitis (cases) and 26 individuals with ALL who did not develop pancreatitis (controls), before and after a single exposure to asparaginase. Screening from this discovery cohort revealed that plasma carotenoids were lower in the cases than in controls. This finding was validated in a larger external cohort. A 30-day dietary recall showed that the cases received less dietary vitamin A than the controls did. In mice, asparaginase administration alone was sufficient to reduce circulating and hepatic retinol. Based on these data, we propose that circulating retinoids protect against pancreatic inflammation and that asparaginase reduces circulating retinoids. Moreover, we show that AAP is more likely to develop with reduced dietary vitamin A intake. The systems approach taken for AAP provides an impetus to examine the role of dietary vitamin A supplementation in preventing or treating AAP.

Multicenter real-world experience of the clinical efficacy and tolerance of pazopanib in high-risk pediatric solid tumors (PazoPed)

Pazopanib, a receptor tyrosine kinase inhibitor, exhibits anti-tumor activity in adult bone and soft-tissue sarcomas (STS), but has not yet been approved for pediatric tumors. The primary objective was to evaluate pazopanib efficacy when used alone or in combination with topotecan. This real-world multicenter retrospective study included patients with solid tumors, aged 25 years or less at the time of initial diagnosis, treated with pazopanib outside of a clinical trial. Nineteen patients were eligible for efficacy analysis: 14 bone tumors and 5 STS. At pazopanib initiation, the median age was 16.9 years, 18 patients had metastatic disease with a median of 2 prior therapeutic lines. With 6.2 months of median follow-up, no objective response was observed, but 10 patients (52.6%) had stable disease at 8 weeks and the 6-month disease control rate was 26.3%. The median progression free (PFS) and overall survival (OS) were 3.0 months and 6.2 months, respectively. Multivariate analysis showed an inverse relationship between the number of prior treatment lines and PFS and OS (hazard ratio = 1.73 (p = 0.04) and 1.76 (p = 0.03), respectively). Our study showed a potential tumor control activity of pazopanib in pediatric bone and soft tissue sarcomas. Further studies are warranted to determine the optimal timing and condition for pazopanib introduction to maximize the effect.

Clinical screening for Ph-like ALL and the developing role of TKIs

Philadelphia chromosome-like acute lymphoblastic leukemia (Ph-like ALL) is a common subtype of B-lineage acute lymphoblastic leukemia (B-ALL) with increasing frequency across the age spectrum. Characterized by a kinase-activated gene expression profile and driven by a variety of genetic alterations involving cytokine receptors and kinases, Ph-like ALL is associated with high rates of residual disease and relapse in patients treated with conventional chemotherapy. In this case-based review, we describe the biology of the 2 major ABL-class and JAK pathway genetic subtypes of Ph-like ALL, discuss current diagnostic testing methodologies, and highlight targeted inhibitor and chemo/immunotherapy approaches under clinical investigation in children, adolescents, and adults with these high-risk leukemias.

Prognostic factors and outcomes of infant acute lymphoblastic leukemia (ALL), hypodiploid ALL, and mixed-phenotype acute leukemia (MPAL) in Canada: a report from CYP-C

The epidemiology of infant acute lymphoblastic leukemia (ALL), hypodiploid ALL, and mixed-phenotype acute leukemia (MPAL) in Canada is unknown. The main objective was to describe the prevalence, prognostic factors, and outcomes of three rare and high-risk ALL subtypes in Canada. This is a retrospective study using the Cancer in Young People-Canada (CYP-C) database. Event-free survival (EFS) and overall survival (OS) were described by the Kaplan-Meier method and compared using the log-rank test. Among 2626 children aged 0-14 years diagnosed with B-cell acute lymphoblastic leukemia (B-ALL) between 2001 and 2018, 227 (8.6%) patients were identified to be infant ALL (n = 139), hypodiploid ALL (n = 43), or MPAL (n = 45). The 5-year EFS/OS was significantly worse in the infant ALL subgroup compared to that of hypodiploid ALL and MPAL. For the entire cohort, presenting White blood cells (WBCs) ≥50 × 10⁹/L was independently associated with worse EFS/OS.

Clinical response to dabrafenib and chemotherapy in clonally-related histiocytosis and acute lymphoblastic leukemia

Not available.

Repurposing alpelisib, an anti-cancer drug, for the treatment of severe TIE2-mutated venous malformations: Preliminary pharmacokinetics and pharmacodynamic data

Extensive venous malformations involving limbs severely impact quality of life, mostly due to chronic pain and functional limitations. But patients can also display coagulopathy with associated risks of life-threatening thromboembolism and bleeding. Available pharmacological treatments (e.g., sirolimus) are not universally effective. Novel therapies are urgently needed for patients with treatment-resistant venous malformations. We report three patients with TIE-2 receptor mutations treated with alpelisib for 6 months (daily dosing: 50 mg for children weighing <50 kg and 100 mg for those >50 kg). Pain was controlled, gait improved, size of the abnormal venous network decreased, and coagulopathy dramatically improved. Drug exposure was highly variable, suggesting that alpelisib dosing should be individualized to patient's characteristics and guided by therapeutic drug monitoring.

Abstract 3897: Ribosomal translational regulation is a potential mechanism for leukemia-related thrombo-embolic event in childhood acute lymphoblastic leukemia

Introduction: Thrombo-embolic event (TE) is a frequent complication of childhood acute lymphoblastic leukemia (cALL) and is associated with reduced survival. Overexpression of podoplanin or coagulome genes and coagulation pathway activation have been identified in cancer-induced TE but the role of leukemia environment in TE occurrence has not been fully elucidated in ALL. We assessed whether leukemia gene expression (GE) signature at diagnosis was associated with TE development in cALL.

Methods: We included children aged 0-18 years old (y.o.), from two hospitals, with newly diagnosed ALL and available RNA sequencing data from bone marrow at diagnosis. The primary outcome was the occurrence of grade ≥2 TE during ALL therapy using the Ponte Di Legno Working Group classification. TEs were classified as early (ET) if they occurred within 6 weeks from treatment start, or late (LT) otherwise. We compared differential gene expression (DE) in children with and without TE, adjusted for age (&lt;10 or ≥10 y.o.) and ALL type (T or B-ALL). A secondary analysis stratified children between ET, LT and no TE. Gene set enrichment analysis (GSEA) was performed on KEGG and gene ontology (GO) databases. DE with absolute fold change ≥2 and p-values &lt;0.05 were considered significant.

Results: We included 80 patients (median age: 5 years [interquartile range, IQR: 3-11 years], 53% male, 83% precursor B-cell ALL) of whom 19 (23.8%) developed a TE (7 ET and 12 LT) at a median of 76 days (IQR: 31-133 days) following cancer diagnosis. Patients with TE were more likely to be ≥10 y.o., while other demographic and clinical characteristics were similar. No genes from the coagulome, podoplanin or Hallmark coagulation pathways were differentially expressed in children with and without TE. The KEGG Ribosome pathway was the most upregulated pathway in the group with TE (normalized enrichment score (NES) = 2.35, adjusted p-value= 0.012) and ET (NES = 2.63, adjusted p-value &lt; 0.001). LT was not significantly associated with ribosome pathway dysregulation. Interestingly, prior reports identified functional enrichment in ribosomal pathway as a biomarker for venous TE. A heatmap classification for ribosomal genes revealed 3 distinct signatures: ribosomal downregulation, moderate and high ribosomal activation. High ribosomal activation profile was seen in 6/7 ET and 9/12 LT, corresponding to a positive and negative predictive value of 0.55 and 0.92 for TE, respectively.

Conclusion: TEs in cALL were not associated with dysregulation in coagulation pathways or podoplanin gene at the RNA level. However, ribosomal translational pathway was highly upregulated in the group with thrombosis, particularly with ET. Dysregulation of posttranscriptional machinery might explain the pro-thrombotic effect of leukemia environment in cALL and warrants further investigation including proteomic exploration.

Citation Format: Marie-Claude Pelland-Marcotte, Meredith Michelle Rémy, Yan Ma, Jessica Liu, Camille Jimenez-Cortes, Thomas Sontag, Maxime Caron, Pascal Saint-Onge, Sylvie Langlois, Charles Joly-Beauparlant, Daniel Sinnett, Arnaud Droit, Thai Hoa Tran, Raoul Santiago. Ribosomal translational regulation is a potential mechanism for leukemia-related thrombo-embolic event in childhood acute lymphoblastic leukemia [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3897.

Minimal residual disease comparison between Ig/TCR PCR versus NGS assays in children with Philadelphia chromosome-positive acute lymphoblastic leukemia: A report from the COG AALL1631 study

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Background: Minimal residual disease (MRD) assessment by immunoglobulin/T-cell receptor (Ig/TCR) polymerase chain reaction (PCR) is currently being used in the international pediatric Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ALL) trial EsPhALL2017/AALL1631 for risk stratification. MRD concordance has previously been demonstrated between Ig/TCR PCR and flow cytometry in Ph+ALL. We sought to assess concordance of MRD assessment between conventional Ig/TCR PCR and next-generation sequencing (NGS) assays. Methods: MRD was assessed in all pts on AALL1631 by Ig/TCR PCR at end-induction IB; those with MRD <5x10-4 were classified as standard-risk (SR) and randomized to treatment with imatinib and one of two chemotherapy regimens without hematopoietic stem cell transplant (HSCT), whereas pts with end-induction 1B MRD ≥ 5x10-4 were considered high-risk (HR) and assigned to HSCT after consolidation chemotherapy. Residual diagnostic and end-induction IB samples from consenting pts were assessed for NGS MRD by the clonoSEQ assay (Adaptive Biotechnologies) in blinded fashion and subsequently compared to Ig/TCR MRD to determine concordance as related to MRD-based HSCT recommendations ( ie, MRD ≥ 5x10-4 consistent with HR group assignment). MRD values were calculated using the kappa statistic for agreement above chance. Results: Sixty-seven pts had matched samples available for MRD assessment at end-induction 1B by both Ig/TCR PCR and NGS (Table). NGS MRD was evaluable for all 67 pts and stratified as 62 SR (<5x10-4) and 5 HR (≥5x10-4). In contrast, Ig/TCR PCR results were inevaluable for 3 pts (unsatisfactory sample quality) and indeterminate (positive, but not quantifiable) in 4 pts. Of the remaining 60 pts, 55 met SR and 5 HR criteria using Ig/TCR PCR. There was only 1 discordant case between the two methods for MRD-based HSCT recommendation among these 60 pts with a kappa statistic for agreement above chance of 0.88. Conclusions: NGS and Ig/TCR PCR assays were highly concordant in MRD assessment for risk stratification at a threshold of 5x10-4 in pediatric pts with Ph+ALL enrolled on AALL1631. Of note, the NGS assay yielded MRD results amenable for risk stratification in 100% pts compared to 89.6% for the Ig/TCR PCR methodology. These data support the use of NGS MRD testing for risk stratification in pediatric Ph+ALL.[Table: see text]

Has Ph-like ALL Superseded Ph+ ALL as the Least Favorable Subtype?

Philadelphia chromosome-like acute lymphoblastic leukemia (Ph-like ALL) is a subset of high-risk B-ALL associated with high relapse risk and inferior clinical outcomes across the pediatric-to-adult age spectrum. Ph-like ALL is characterized by frequent IKZF1 alterations and a kinase-activated gene expression profile similar to that of Philadelphia chromosome-positive (Ph+) ALL, yet lacks the canonical BCR-ABL1 rearrangement. Advances in high-throughput sequencing technologies during the past decade have unraveled the genomic landscape of Ph-like ALL, revealing a diverse array of kinase-activating translocations and mutations that may be amenable to targeted therapies that have set a remarkable precision medicine paradigm for patients with Ph + ALL. Collaborative scientific efforts to identify and characterise Ph-like ALL during the past decade has directly informed current precision medicine trials investigating the therapeutic potential of tyrosine kinase inhibitor-based therapies for children, adolescents, and adults with Ph-like ALL, although the most optimal treatment paradigm for this high-risk group of patients has yet to be established. Herein, we describe the epidemiology, clinical features, and biology of Ph-like ALL, highlight challenges in implementing pragmatic and cost-effective diagnostic algorithms in the clinic, and describe the milieu of treatment strategies under active investigation that strive to decrease relapse risk and improve long-term survival for patients with Ph-like ALL as has been successfully achieved for those with Ph + ALL.

Advancement of Microwave-Assisted Biosynthesis for Preparing Au Nanoparticles Using Ganoderma lucidum Extract and Evaluation of Their Catalytic Reduction of 4-Nitrophenol

This study describes the biosynthesis of gold nanoparticles (AuNPs) using the extract of Ganoderma lucidum in the buffer zone of Bach Ma National Park, Vietnam, as a reducing and protecting agent using microwave-assisted synthesis. The as-synthesized AuNPs were characterized using transmission electron microscopy, scanning electron microscopy, X-ray diffraction, energy-dispersive X-ray spectroscopy, and Fourier transform infrared spectroscopy. Compared to the conventional method, the proposed microwave-assisted method produced AuNPs having a small size of 22.07 ± 8.11 nm in a short synthesis time period. In excess NaBH₄, the as-prepared AuNPs demonstrated good catalytic activity for reducing 4-nitrophenol to 4-aminophenol. Furthermore, AuNPs demonstrated improved reusability after four cycles. The pseudo-first-order apparent rate constant was estimated to be 0.086 min^-1 at 303 K. Both the catalytic mechanism and reaction path of reduction were proposed. Moreover, activation energy and thermodynamic parameters, including activation enthalpy and entropy, were examined.

Molecular-based and antibody-based targeted pharmacological approaches in childhood acute lymphoblastic leukemia

Introduction: Despite the significant survival improvement in childhood acutelymphoblastic leukemia (ALL), 15-20% of patients continue to relapse; outcomes following relapse remain suboptimal and have room for further improvement. Advances in genomics have shed new insights on the biology of ALL, led to the discovery of novel genomically defined ALL subtypes, refined prognostic significance and revealed new therapeutic vulnerabilities.Areas covered: In this review, the authors provide an overview of the genomic landscape of childhood ALL and highlight recent advances in molecular-based and antibody-based pharmacological approaches in the treatment of childhood ALL, from emerging preclinical evidence to published results of completed clinical trials.Expert opinion: Molecularly targeted therapies and immunotherapies have expanded the horizons of ALL therapy and represent promising therapeutic avenues for high-risk and relapsed/refractory ALL. These novel therapies are now moving into frontline ALL therapy and may define new treatment paradigms that aim to further improve survival and reduce chemotherapy-related toxicities in the management of pediatric ALL.

The genomic landscape of pediatric acute lymphoblastic leukemia and precision medicine opportunities

Acute lymphoblastic leukemia (ALL) is the most common childhood cancer and constitutes approximately 25 % of cancer diagnoses among children under the age of 15 (Howlader et al., 2013) [1]. Overall, about half of ALL cases occur in children and adolescents and it is the most common acute leukemia until the early 20s, after which acute myeloid leukemia predominates. ALL is the most successful treatment paradigm in pediatric cancer medicine as illustrated by the significant survival rate improvement from ∼10 % in the 1960s to >90 % today (Hunger et al., 2015) [2]. This remarkable success stems from the progressive improvement in the efficacy of risk-adapted multiagent chemotherapy regimens with effective central nervous system (CNS) prophylaxis via well-designed randomized clinical trials conducted by international collaborative consortia, enhanced supportive care measures to decrease treatment-related mortality, in-depth understanding of the genetic basis of ALL, and refinement in treatment response assessment through serial minimal residual disease (MRD) monitoring (Pui et al., 2015) [3]. These advances collectively contribute to a decline in mortality rate of 23.5% for children diagnosed with ALL in the US from 2000 to 2010 (Smith et al., 2014) [4]. Nevertheless, outcomes of older adolescents and young adults with ALL still lag behind those of their younger counterparts despite pediatric-inspired chemotherapy regimens (Stock et al., 2019) [5], relapsed/refractory childhood ALL is associated with poor outcomes (Rheingold et al., 2019) [6], and ALL still represents the leading causes of cancer-related deaths (Smith et al., 2010) [7]. The last two decades have witnessed important genomic discoveries in ALL, enabled by advances in next-generation sequencing (NGS) technologies to characterize the landscape of germline and somatic alterations in ALL, some of which have important diagnostic, prognostic and therapeutic implications. Comprehensive genomic analysis of large cohorts of children and adults with ALL has revised the taxonomy of ALL in the molecular era by identifying novel clonal, subtype-defined chromosomal alterations associated with distinct gene expression signatures, thus reducing the proportion of patients previously labelled as "Others" from 25 % to approximately 5 % (Mullighan et al., 2019) [8]. Insights into the genomics of ALL further provide compelling biologic rationale to expand the scope of precision medicine therapies for childhood ALL. Herein, we summarize a decade of genomic discoveries to highlight three different facets of precision medicine in pediatric ALL: 1) inherited predispositions of ALL; 2) relevant molecularly targeted therapies in genomically-defined ALL subtypes; and 3) treatment response monitoring via pharmacogenomics and novel MRD biomarkers.

Abstract S12-01: High mortality among hospital-acquired COVID-19 infection in patients with cancer: An observational cohort study from Quebec and British Columbia

Background: Studies suggest that patients with cancer are more likely to experience severe outcomes from COVID-19. Therefore, cancer centers have undertaken efforts to care for patients with cancer in COVID-free zones. Nevertheless, nosocomial transmission of COVID-19 in patients with cancer likely occurs, but the frequency and relevance of these events remain unknown. The goal of this study was to determine the incidence and impact of hospital-acquired COVID-19 in this population and identify prognostic factors for COVID-19 severity in patients with cancer.

Methods: Patients with cancer and a laboratory-confirmed or presumed diagnosis of COVID-19 were prospectively identified using provincial registries and hospital databases between March 3rd and May 23rd, 2020, in the provinces of Quebec and British Columbia. Patients’ baseline characteristics including age, sex, comorbidities, cancer type, and type of anticancer treatment were collected. The primary outcome was incidence of hospital-acquired infection defined by diagnosis of SARS-CoV-2 5 days after hospital admission for COVID-unrelated cause. Co-primary outcomes were death or composite outcomes of severe illness from COVID-19 such as hospitalization, supplemental oxygen, intensive-care unit (ICU) admission, and/or mechanical ventilation.

Results: A total of 253 patients (N=250 adult and N=3 pediatric) with COVID-19 and cancer were identified, and the majority were residents of Quebec (N=236). Ninety patients (35.6%) received active anticancer treatment in the last 3 months prior to COVID-19 diagnosis. During a median follow-up of 23 days, 209 (82.6%) required hospitalization, 38 (15%) required admission to ICU, and 71 (28%) died. Forty-seven (19%) had a diagnosis of hospital-acquired COVID-19. Median overall survival was shorter in those with hospital-acquired infection, compared to a contemporary community-acquired population (27 days vs. 71 days, HR 2.2, 95% CI 1.2-4.0, p=0.002). Multivariate analysis demonstrated that hospital-acquired COVID-19, age, ECOG status, and advanced stage of cancer were independently associated with death.

Conclusion: Our study demonstrates a high rate of nosocomial transmission of COVID-19, associated with increased mortality in both univariate and multivariate analysis in the cancer population, reinforcing the importance of treating patients with cancer in COVID-free zones. We also validated that age, poor ECOG, and advanced cancer were negative prognostic factors for COVID-19 in patients with cancer.

Citation Format: Arielle Elkrief, Antoine Desilets, Neha Papneja, Lena Cvetkovic, Catherine Groleau, Yahia Abdelali Lakehal, Layla Shbat, Corentin Richard, Julie Malo, Wiam Belkaid, Erin Cook, Stephane Doucet, Thai Hoa Tran, Patrice Savard, Kevin Jao, Nathalie Daaboul, Eric Bhang, Jonathan Loree, Wilson Miller, Donald Vinh, Nathaniel Bouganim, Gerald Batist, Caroline Letendre, Bertrand Routy. High mortality among hospital-acquired COVID-19 infection in patients with cancer: An observational cohort study from Quebec and British Columbia [abstract]. In: Proceedings of the AACR Virtual Meeting: COVID-19 and Cancer; 2020 Jul 20-22. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(18_Suppl):Abstract nr S12-01.

High mortality among hospital-acquired COVID-19 infection in patients with cancer: A multicentre observational cohort study

INTRODUCTION

Studies suggest that patients with cancer are more likely to experience severe outcomes from COVID-19. Therefore, cancer centres have undertaken efforts to care for patients with cancer in COVID-free units. Nevertheless, the frequency and relevance of nosocomial transmission of COVID-19 in patients with cancer remain unknown. The goal of this study was to determine the incidence and impact of hospital-acquired COVID-19 in this population and identify predictive factors for COVID-19 severity in patients with cancer.

METHODS

Patients with cancer and a laboratory-confirmed diagnosis of COVID-19 were prospectively identified using provincial registries and hospital databases between March 3rd and May 23rd, 2020 in the provinces of Quebec and British Columbia in Canada. Patient's baseline characteristics including age, sex, comorbidities, cancer type and type of anticancer treatment were collected. The exposure of interest was incidence of hospital-acquired infection defined by diagnosis of SARS-CoV-2 ≥ 5 days after hospital admission for COVID-unrelated cause. Co-primary outcomes were death or composite outcomes of severe illness from COVID-19 such as hospitalisation, supplemental oxygen, intensive-care unit (ICU) admission and/or mechanical ventilation.

RESULTS

A total of 252 patients (N = 249 adult and N = 3 paediatric) with COVID-19 and cancer were identified, and the majority were residents of Quebec (N = 233). One hundred and six patients (42.1%) received active anticancer treatment in the last 3 months before COVID-19 diagnosis. During a median follow-up of 25 days, 33 (13.1%) required admission to the ICU, and 71 (28.2%) died. Forty-seven (19.1%) had a diagnosis of hospital-acquired COVID-19. Median overall survival was shorter in those with hospital-acquired infection than that in a contemporary community-acquired population (27 days versus unreached, hazard ratio (HR) = 2.3, 95% CI: 1.2-4.4, p = 0.0006. Multivariate analysis demonstrated that hospital-acquired COVID-19, age, Eastern Cooperative Oncology Group status and advanced stage of cancer were independently associated with death.

INTERPRETATION

Our study demonstrates a high rate of nosocomial transmission of COVID-19, associated with increased mortality in both univariate and multivariate analysis in the cancer population, reinforcing the importance of treating patients with cancer in COVID-free units. We also validated that age and advanced cancer were negative predictive factors for COVID-19 severity in patients with cancer.

IKZF1 alterations in acute lymphoblastic leukemia: The good, the bad and the ugly

Advances in genomics have deepened our understanding of the biology of acute lymphoblastic leukemia (ALL), defined novel molecular leukemia subtypes, discovered new prognostic biomarkers and paved the way to emerging molecularly targeted therapeutic avenues. Since its discovery, IKZF1 has generated significant interest within the leukemia scientific community.IKZF1 plays a critical role in lymphoid development and its alterations cooperate to mediate leukemogenesis. IKZF1 alterations are present in approximately 15% of childhood ALL, rise in prevalence among adults with ALL and become highly enriched within kinase-driven ALL. A cumulating body of literature has highlighted the adverse prognostic impact of IKZF1 alterations in both Philadelphia chromosome (Ph)-negative and Ph-driven ALL. IKZF1 alterations thus emerge as an important prognostic biomarker in ALL. This article aims to provide a state-of-the-art review focusing on the prognostic clinical relevance of IKZF1 alterations in ALL, as well as current and future therapeutic strategies targeting IKZF1-altered ALL.

Molecular Profiling of Hard-to-Treat Childhood and Adolescent Cancers

IMPORTANCE

Little progress in pediatric cancer treatment has been noted in the past decade, urging the development of novel therapeutic strategies for adolescents and children with hard-to-treat cancers. Use of comprehensive molecular profiling in the clinical management of children and adolescents with cancer appears a suitable approach to improve patient care and outcomes, particularly for hard-to-treat cases.

OBJECTIVE

To assess the feasibility of identifying potentially actionable mutations using next-generation sequencing-based assays in a clinically relevant time frame.

DESIGN, SETTING, AND PARTICIPANTS

This diagnostic study reports the results of the TRICEPS study, a prospective genome sequencing study conducted in Québec, Canada. Participants, aged 18 years or younger at diagnosis, with refractory or relapsed childhood and adolescent cancers were enrolled from April 2014 through January 2018. Whole-exome sequencing (WES) of matched tumor normal samples and RNA sequencing of tumor were performed to identify single-nucleotide variants, fusion transcripts, differential gene expression, and copy number alterations. Results reviewed by a team of experts were further annotated, synthesized into a report, and subsequently discussed in a multidisciplinary molecular tumor board.

MAIN OUTCOMES AND MEASURES

Molecular profiling of pediatric patients with hard-to-treat cancer, identification of actionable and targetable alteration needed for the management of these patients, and proposition of targeted and personalized novel therapeutic strategies.

RESULTS

A total of 84 patients with hard-to-treat cancers were included in the analysis. These patients had a mean (range) age of 10.1 (1-21) years and a similar proportion of male (45 [54%]) and female (39 [46%]). Sixty-two patients (74%) had suitable tissues for multimodal molecular profiling (WES and RNA sequencing). The process from DNA or RNA isolation to genomic sequencing and data analysis steps took a median (range) of 24 (4-41) days. Potentially actionable alterations were identified in 54 of 62 patients (87%). Actions were taken in 22 of 54 patients (41%), and 18 (33%) either were on a second or third line of treatment, were in remission, or had stable disease and thus no actions were taken.

CONCLUSIONS AND RELEVANCE

Incorporating genomic sequencing into the management of hard-to-treat childhood and adolescent cancers appeared feasible; molecular profiling may enable the identification of potentially actionable alterations with clinical implications for most patients, including targeted therapy and clinically relevant information of diagnostic, prognostic, and monitoring significance.

In Vitro Effects of the Acylated StreptokinasePlasminogen Activator Complex BRL 33 575 Incubated with Normal Human Plasma

Thrombolysis with acylated streptokinase-plasminogen complexes is aimed to achieve fibrinolysis without systemic fibrinogenolysis. The p-aminobenzoyl-streptokinase-(Lys)-plasminogen-complex (BRL 33 575) should be particularly useful due to its slow deacylation rate. Unexpectedly, repeated doses of 10 mg of BRL 33 575 (corresponding to 310'000 streptokinase equivalent units) induced systemic effects in patients though less than streptokinase alone. In vitro incubation of normal human plasma with BRL 33 575 at concentrations used in patients resulted in nearly complete consumption of α2-antiplasmin and plasminogen and significant fibrinogenolysis within 3 hr. This demonstrates that - despite of slow deacylation of BRL 33 575 - the small amounts of activator generated are highly efficacious in activating plasma plasminogen under conditions in which no physiological clearance of the free activator takes place. Simulating the calculated activator release from BRL 33 575 by infusing equivalent amounts of streptokinase into plasma resulted in less pronounced effects. This is probably explained by anti-streptokinase antibodies which will neutralize the initially infused streptokinase but will be bound by BRL 33 575.

Our in vitro experiments indicate that further clinical studies should be done with lower doses of BRL 33 575 or prolonged dosage intervals.

Fifteen Coagulation and Fibrinolysis Parameters in Diabetes Mellitus and in Patients with Vasculopathy

Fifteen haemostasis parameters have been measured in 48 normal persons, 36 diabetics without and 44 with complications and 27 with peripheral arterial disease. Since the patients groups are older than normals, part of the differences are due to age. However, the differences are significant between normals and patients. They become highly significant for the diabetics with complications and nephropathy (Table 7). In diabetics without complications factor VIII functions, fibrinogen and thrombin time are related to age whereas there is a negative correlation for the fibrinolytic activity and antithrombin III. The diabetic complications shade off the correlations, which subsist only for VIIIR: CoF, VIIIR: Ag, ATIII and lysis before stasis. With Hbalc as dependent variable VIIIR:CoF is the only significant predictor variable in diabetics (Table 9).

Dissociation of Factor VIII Procoagulant Antigen VIII : CAg and Factor VIII Related Antigen VIIIR : Ag by EDTA - Influence of Divalent Cation on the Binding of VIII: CAg and VIIIR :Ag

Assuming 1 U/ml in titrated plasma, the VIII: CAg concentration was found 1.66 U/ml in EDTA-plasma, 1.09 U/ml in heparinized plasma and 0.67 U/ml in serum. Addition of 10 mmol/1 EDTA to titrated and heparinized plasmas increased VIII: CAg 1.5fold. There was no increase of VIII: CAg in serum. Gel filtration of plasmas on different anticoagulants showed an elution of VIII: CAg in the void volume Vo and in the later fractions. The VIII: CAg amount detected in the internal volume increased following the series heparin < citrate < EDTA. Serum VIII: CAg was eluted at 2.2 Vo. Presence of EDTA in the elution buffer or incubation of plasma with EDTA prior to chromatography caused a displacement of practically all VIII: CAg amount in the internal volume with a peak at 2.2-2.3 Vo. VIIIR: Ag was exclusively detected in the void volume.

Removal of divalent cation by chelation likely exposes more antigenic determinants of VIII: CAg, which are otherwise masked by steric hindrance due to VIIIR: Ag in citrated and heparinized milieu. Moreover gel filtration of plasma in the presence of EDTA completely dissociates VIII: CAg from VIIIR :Ag. The VIII: CAg fragment, having an estimated molecular weight of 70,000, might also be present in serum.

Purification and Partial Characterization of a Hereditary Abnormal Antithrombin III Fraction of a Patient with Recurrent Thrombophlebitis

A relatively low heparin cofactor activity (0.60 U/ml) was observed in a patient with recurrent superficial thrombophlebitis of the left leg. However, the antigen concentration was in the normal range (1.04 U/ml) and the progressive antithrombin activity was normal. The crossed immunoelectrophoresis in presence of heparin in agarose gel separated the patient's AT-III antigen in 2 fractions with different mobilities. The patient's AT-III was purified for further characterization. The last step of the purification procedure, a heparin-agarose chromatography, led to a separation and a purification of 2 AT-III fractions with different heparin affinities: an abnormal AT-III with reduced heparin affinity and a normal AT-III with a heparin affinity similar to that of AT-III isolated from normal plasmas. Abnormal and normal AT-III share several identical properties as molecular weight, ability to form complexes with thrombin and progressive antithrombin activity.

Reactivity of a Hereditary Abnormal Antithrombin III Fraction in the Inhibition of Thrombin and Factor Xa

Two different AT-III fractions were purified from the plasma of a patient with recurrent superficial thrombophlebitis. The abnormal AT-III fraction (A-AT) was compared to the normal AT-III fraction (N-AT) in the inhibition of thrombin and factor Xa. Without heparin, both inactivate proteases in a similar manner and at the same rate. However, at low heparin concentration the thrombin inhibition proceeds more slowly with A-AT than with N-AT. At high heparin concentration the difference between A-AT and N-AT becomes very small. The inhibition of factor Xa follows a similar pattern. It is suggested that the heparin binding site of A-AT differs from that of N-AT resulting in a decreased heparin cofactor activity.

Rabbit Antibodies Against the Procoagulant Activity (VIII:C) of Human Factor VIII

The procoagulant activity VIII:C was separated from factor VIII antigen (VIIIR:Ag) by gel filtration in the presence of 0.25 mol/l calcium chloride. Antibodies (anti-VIII:C) were obtained by immunization of rabbits with VIII:C. The last step of the purification procedure of antibodies consists of an adsorption on VIIIR:Ag-Sepharose 2 BCL as immunoadsorbent to remove contaminating traces of antibodies against VIIIR:Ag. The anti- VIII:C titer remains unchanged during this adsorption (29 Bethesda units per mg). In solution, anti-VIII:C neutralies factor VIII activity (in plasma, cryoprecipitate or in purified form) and the fragment VIII:C without reacting with VIIIR:Ag. Once immobilized on a solid matrix, i.e.2% agarose, it loses over 95% of its inhibitory capacity. The immobilized anti-VIIIR:Ag binds stoichiometrically the antigen and the activity of plasma factor VIII. These results together suggest that factor VIII is composed of 2 different entities, but undissociated under physiological conditions. Immunophysical analyses as a function of pH and temperature of anti-VIII:C and its complex with factor VIII show properties similar to those of homologous antibodies. The antigen determinants of VIII:C (VIII:CAg) are destroyed at low pHs or high temperatures, and VIII:C can no more form a complex with anti-VIII:C. Purified anti-VIII:C is also used in a two-stage assay to detect VIII:CAg or cross-reacting material in some severe haemophiliacs.

Philadelphia chromosome-like acute lymphoblastic leukemia: A review of the genetic basis, clinical features, and therapeutic options

Philadelphia chromosome-like acute lymphoblastic leukemia (Ph-like ALL) is a recently identified high-risk subtype of B-lineage ALL (B-ALL), characterized by a gene expression profile similar to that of Philadelphia-positive (Ph+) ALL, but without the hallmark BCR-ABL1 oncoprotein. Ph-like ALL represents approximately 15% of childhood ALL and its frequency rises with age, peaking among adolescents, and young adults with B-ALL. This subtype is associated with adverse clinical features, persistence of minimal residual disease, and a poor prognosis despite modern chemotherapy regimens. While Ph-like ALL lacks the BCR-ABL1 fusion, it is characterized by a diverse spectrum of kinase fusions and cytokine receptor gene rearrangements that may be similarly amenable to molecularly targeted therapies. While survival rates for childhood ALL have drastically improved with intensive conventional chemotherapy, Ph-like ALL represents a novel paradigm of precision medicine in ALL. This review aims to provide a comprehensive review of the clinical picture and genetic basis of Ph-like ALL and to illustrate how these findings can translate into tailored targeted therapies with the hopes of improving the outcomes of Ph-like ALL patients.

Precision Medicine in Pediatric Oncology: Translating Genomic Discoveries into Optimized Therapies

Survival of children with cancers has dramatically improved over the past several decades. This success has been achieved through improvement of combined modalities in treatment approaches, intensification of cytotoxic chemotherapy for those with high-risk disease, and refinement of risk stratification incorporating novel biologic markers in addition to traditional clinical and histologic features. Advances in cancer genomics have shed important mechanistic insights on disease biology and have identified "driver" genomic alterations, aberrant activation of signaling pathways, and epigenetic modifiers that can be targeted by novel agents. Thus, the recently described genomic and epigenetic landscapes of many childhood cancers have expanded the paradigm of precision medicine in the hopes of improving outcomes while minimizing toxicities. In this review, we will discuss the biologic rationale for molecularly targeted therapies in genomically defined subsets of pediatric leukemias, solid tumors, and brain tumors. Clin Cancer Res; 23(18); 5329-38. ©2017 AACR.

Child pneumonia - focus on the Western Pacific Region

Worldwide, pneumonia is the leading cause of death in infants and young children (aged <5 years). We provide an overview of the global pneumonia disease burden, as well as the aetiology and management practices in different parts of the world, with a specific focus on the WHO Western Pacific Region. In 2011, the Western Pacific region had an estimated 0.11 pneumonia episodes per child-year with 61,900 pneumonia-related deaths in children less than 5 years of age. The majority (>75%) of pneumonia deaths occurred in six countries; Cambodia, China, Laos, Papua New Guinea, the Philippines and Viet Nam. Historically Streptococcus pneumoniae and Haemophilus influenzae were the commonest causes of severe pneumonia and pneumonia-related deaths in young children, but this is changing with the introduction of highly effective conjugate vaccines and socio-economic development. The relative contribution of viruses and atypical bacteria appear to be increasing and traditional case management approaches may require revision to accommodate increased uptake of conjugated vaccines in the Western Pacific region. Careful consideration should be given to risk reduction strategies, enhanced vaccination coverage, improved management of hypoxaemia and antibiotic stewardship.

Ph-like acute lymphoblastic leukemia

Philadelphia chromosome-like acute lymphoblastic leukemia (Ph-like ALL) is a newly identified high-risk (HR) B-lineage ALL subtype, accounting for ∼15% of children with National Cancer Institute-defined HR B-ALL. It occurs more frequently in adolescents and adults, having been reported in as much as 27% of young adults with ALL between 21 and 39 years of age. It exhibits adverse clinical features, confers a poor prognosis, and harbors a diverse range of genetic alterations that activate cytokine receptor genes and kinase signaling pathways, making it amenable to treatment with tyrosine kinase inhibitor (TKI) therapy. Multiple groups are currently conducting clinical trials to prospectively screen patients with Ph-like ALL and incorporate the relevant TKI for those harboring ABL-class gene rearrangements or those with JAK-STAT pathway alterations. The success of combinatorial treatment of TKI with chemotherapy in the setting of Ph-positive ALL suggests that this approach may similarly improve outcomes for patients with Ph-like ALL. Hence, Ph-like ALL illustrates the modern treatment paradigm of precision medicine and presents unique opportunities for harnessing international collaborations to further improve outcomes for patients with ALL.

Correlations among four measures of thoracic kyphosis in older adults

SUMMARY

There are many ways to measure thoracic kyphosis ranging from simple clinical to more complex assessments. We evaluated the correlation among four commonly used kyphosis measures: Cobb angle, Debrunner kyphometer, kyphotic index, and the blocks method. Each measure was correlated with the others, confirming high clinical and research applicability.

INTRODUCTION

The purpose of this study was to assess the associations among four commonly used measures of thoracic kyphosis in older adults.

METHODS

Seventy two men and women aged 65-96 were recruited from the San Diego community. Four kyphosis measures were assessed in the same person during a baseline clinic visit. Two measures were done in the lying (L) and two in the standing (ST) position: (1) Cobb angle calculated from dual X-Ray absorptiometry (DXA) images (L), (2) Debrunner kyphometer (DK) angle measured by a protractor (ST), (3) kyphotic index (KI) calculated using an architect's flexicurve ruler (ST), and (4) the blocks method involving counting the number of 1.7 cm-thick blocks required to achieve a neutral head position while lying flat on the DXA table (L). Spearman rank correlation coefficients were used to determine the strength of the association between each kyphosis measure.

RESULTS

Using the Cobb angle as the gold standard, the blocks method demonstrated the lowest correlation (r(s) = 0.63, p < 0.0001), the Debrunner method had a moderate correlation (r(s) = 0.65, p < 0.0001), and the kyphotic index had the highest correlation (r(s) = 0.68, p < 0.0001). The correlation was strongest between the kyphotic index and the Debrunner kyphometer (r(s) = 0.76, p < 0.0001).

CONCLUSION

In older men and women, all four measures of thoracic kyphosis were significantly correlated with each other, whether assessed in the lying or standing position. Thus, any of these measures demonstrate both potential clinical and research utility.

Rapid rule out of myocardial infarction with the use of copeptin as a biomarker for cardiac injury

Copeptin is a non-specific marker of an endogenous stress response. A dual biomarker marker approach involving the simultaneous use of troponin and copeptin assays may assist early exclusion of acute coronary syndrome in Australian emergency departments. The utility and limitations of this approach are discussed.