The genomic landscape of pediatric acute lymphoblastic leukemia

Acute lymphoblastic leukemia (ALL) is the most common childhood cancer. Here, using whole-genome, exome and transcriptome sequencing of 2,754 childhood patients with ALL, we find that, despite a generally low mutation burden, ALL cases harbor a median of four putative somatic driver alterations per sample, with 376 putative driver genes identified varying in prevalence across ALL subtypes. Most samples harbor at least one rare gene alteration, including 70 putative cancer driver genes associated with ubiquitination, SUMOylation, noncoding transcripts and other functions. In hyperdiploid B-ALL, chromosomal gains are acquired early and synchronously before ultraviolet-induced mutation. By contrast, ultraviolet-induced mutations precede chromosomal gains in B-ALL cases with intrachromosomal amplification of chromosome 21. We also demonstrate the prognostic significance of genetic alterations within subtypes. Intriguingly, DUX4- and KMT2A-rearranged subtypes separate into CEBPA/FLT3- or NFATC4-expressing subgroups with potential clinical implications. Together, these results deepen understanding of the ALL genomic landscape and associated outcomes.

Comparison of chemotherapy dose intensity for AYAs on COG AALL1131 versus CALGB 10403

10520

Background: Outcomes for adolescents and young adults (AYAs) with acute lymphoblastic leukemia (ALL) are superior with pediatric-inspired therapy. CALGB 10403, the first US adult cooperative group prospective trial using a pediatric-inspired augmented BFM (ABFM)-based regimen, demonstrated feasibility and improved survival. We examined differences in drug delivery and targeted toxicities in AYAs who received the same therapy on C10403 vs the Children’s Oncology Group (COG) study AALL1131. Methods: The proportion of AYAs receiving full dose (within 10% of protocol- specified) vincristine (VCR) and pegaspargase (PEG) during induction (IND), consolidation (CON), and delayed intensification (DI); the likelihood of selected grade ≥3 adverse events (AEs); and the impact of patient characteristics were compared in AYAs 16-30 years. Targeted AEs with analogous reporting requirements in both studies included hyperbilirubinemia, pancreatitis, sensory neuropathy, and GI/intracranial hemorrhage. Thrombosis, transaminitis and hyperglycemia were not comparably captured. Fisher’s Exact test and logistic regression models were used for analyses. Results: After excluding AYAs removed from study after induction, 87 AALL1131 AYAs (accrued 2012-2016) and 188 C10403 AYAs (accrued 2007-2012) were analyzed with median ages of 17 (16-26) vs 22 (17-30) years, p < 0.001. There was no difference in the intensity of VCR delivery during IND, but in CON and DI, AALL1131 AYAs were more likely to receive all specified VCR (93.1% vs 81.9%, p = 0.02; 92.7% vs 72.1%, p = 0.01). Women were less likely to receive all specified VCR (OR 0.57, 95% CI 0.34-0.94, p = 0.03), and overweight/obese AYAs were somewhat less likely to receive all VCR compared to those considered normal weight (OR 0.88 and 0.59, p = 0.09). More C10403 AYAs were obese/overweight compared to AALL1131 AYAs (p = 0.04). There were no significant differences in dosing of PEG during IND/CON, but in DI AALL1131 AYAs were more likely to receive both doses (75.6% vs 57.1%, p = 0.03). No patient variables impacted delivery of PEG. There was no significant difference in grade ≥3 toxicities captured similarly on both studies. Conclusions: AYAs enrolled on AALL1131 were more likely to receive all protocol-specified VCR and PEG compared to those on C10403. Selected AE rates were comparable, suggesting that older AYAs do not tolerate doses of VCR and PEG for reasons other than toxicity, with body habitus as one potential variable. Further analyses to compare dose density, toxicities, and outcomes experienced by younger AYAs versus older are ongoing.

Tetracyclines for Treatment of Tularemia: A Case Series

Tetracyclines for tularemia have been associated with higher failure rates. There were 48 cases of tularemia at the University of Missouri between 1988 and 2015. We retrospectively analyzed 17 patients with tularemia who were successfully treated with tetracyclines, and 9 of these patients also underwent aspiration or incision and drainage.

Severe pegaspargase hypersensitivity reaction rates (grade ≥3) with intravenous infusion vs. intramuscular injection: analysis of 54,280 doses administered to 16,534 patients on children's oncology group (COG) clinical trials

PEGylated asparaginase (pegaspargase) can be administered via intramuscular (IM) injection or intravenous (IV) infusion with a hypersensitivity reaction (HSR) incidence ranging 3-41%. We evaluated grade ≥3 HSRs when given IM vs. IV on six Children's Oncology Group (COG) leukemia trials (2003-2015) to determine differences in HSR rates. 54,280 doses were administered to 16,534 patients. Considering all doses of pegaspargase during induction, consolidation, and delayed intensification, grade ≥3 HSR rate with IM injection was 5.4% (n = 482/8981) compared to 3.2% for IV (n = 245/7553) (p < .0001). If only the second and third doses of pegaspargase were analyzed, where the majority of grade ≥3 HSRs occur, the rate following IM injection was 10.1% (n = 459/4534) compared to 5.0% (n = 222/4443) for IV (p < .0001). On standardized treatment protocols conducted by the COG during 2003-2015, grade ≥3 HSR rates to pegaspargase occurred less frequently with IV infusion than IM injection.

A Review of the Effectiveness of Neuroimaging Modalities for the Detection of Traumatic Brain Injury

The incidence of traumatic brain injury (TBI) in the United States was 3.5 million cases in 2009, according to the Centers for Disease Control and Prevention. It is a contributing factor in 30.5% of injury-related deaths among civilians. Additionally, since 2000, more than 260,000 service members were diagnosed with TBI, with the vast majority classified as mild or concussive (76%). The objective assessment of TBI via imaging is a critical research gap, both in the military and civilian communities. In 2011, the Department of Defense (DoD) prepared a congressional report summarizing the effectiveness of seven neuroimaging modalities (computed tomography [CT], magnetic resonance imaging [MRI], transcranial Doppler [TCD], positron emission tomography, single photon emission computed tomography, electrophysiologic techniques [magnetoencephalography and electroencephalography], and functional near-infrared spectroscopy) to assess the spectrum of TBI from concussion to coma. For this report, neuroimaging experts identified the most relevant peer-reviewed publications and assessed the quality of the literature for each of these imaging technique in the clinical and research settings. Although CT, MRI, and TCD were determined to be the most useful modalities in the clinical setting, no single imaging modality proved sufficient for all patients due to the heterogeneity of TBI. All imaging modalities reviewed demonstrated the potential to emerge as part of future clinical care. This paper describes and updates the results of the DoD report and also expands on the use of angiography in patients with TBI.

Pharmacotherapy of traumatic brain injury: state of the science and the road forward: report of the Department of Defense Neurotrauma Pharmacology Workgroup

Despite substantial investments by government, philanthropic, and commercial sources over the past several decades, traumatic brain injury (TBI) remains an unmet medical need and a major source of disability and mortality in both developed and developing societies. The U.S. Department of Defense neurotrauma research portfolio contains more than 500 research projects funded at more than $700 million and is aimed at developing interventions that mitigate the effects of trauma to the nervous system and lead to improved quality of life outcomes. A key area of this portfolio focuses on the need for effective pharmacological approaches for treating patients with TBI and its associated symptoms. The Neurotrauma Pharmacology Workgroup was established by the U.S. Army Medical Research and Materiel Command (USAMRMC) with the overarching goal of providing a strategic research plan for developing pharmacological treatments that improve clinical outcomes after TBI. To inform this plan, the Workgroup (a) assessed the current state of the science and ongoing research and (b) identified research gaps to inform future development of research priorities for the neurotrauma research portfolio. The Workgroup identified the six most critical research priority areas in the field of pharmacological treatment for persons with TBI. The priority areas represent parallel efforts needed to advance clinical care; each requires independent effort and sufficient investment. These priority areas will help the USAMRMC and other funding agencies strategically guide their research portfolios to ensure the development of effective pharmacological approaches for treating patients with TBI.

Phase 2 randomized, flexible crossover, double-blinded, placebo-controlled trial of the farnesyltransferase inhibitor tipifarnib in children and young adults with neurofibromatosis type 1 and progressive plexiform neurofibromas

BACKGROUND

RAS is dysregulated in neurofibromatosis type 1 (NF1) related plexiform neurofibromas (PNs). The activity of tipifarnib, which blocks RAS signaling by inhibiting its farnesylation, was tested in children and young adults with NF1 and progressive PNs.

METHODS

Patients aged 3-25 years with NF1-related PNs and imaging evidence of tumor progression were randomized in a double-blinded fashion to receive tipifarnib (200 mg/m(2) orally every 12 h) or placebo (phase A) and crossed over to the opposite treatment arm at the time of tumor progression (phase B). PN volumes were measured with MRI, and progression was defined as ≥20% volume increase. Time to progression (TTP) in phase A was the primary endpoint, and the trial was powered to detect whether tipifarnib doubled TTP compared with placebo. Toxicity, response, and quality of life were also monitored.

RESULTS

Sixty-two patients were enrolled. Tipifarnib and placebo were well tolerated. On phase A, the median TTP was 10.6 months on the placebo arm and 19.2 months on the tipifarnib arm (P = .12; 1-sided). Quality of life improved significantly compared with baseline on the tipifarnib arm but not on the placebo arm. Volumetric tumor measurement detected tumor progression earlier than conventional 2-dimensional (WHO) and 1-dimensional (RECIST) methods.

CONCLUSIONS

Tipifarnib was well tolerated but did not significantly prolong TTP of PNs compared with placebo. The randomized, flexible crossover design and volumetric PN assessment provided a feasible and efficient means of assessing the efficacy of tipifarnib. The placebo arm serves as an historical control group for phase 2 single-arm trials directed at progressive PNs.

18-fluorodeoxyglucose-positron emission tomography (FDG-PET) evaluation of nodular lesions in patients with Neurofibromatosis type 1 and plexiform neurofibromas (PN) or malignant peripheral nerve sheath tumors (MPNST)

BACKGROUND

Individuals with Neurofibromatosis type 1 (NF1) are at risk for developing malignant peripheral nerve sheath tumors (MPNST), which frequently arise in preexisting plexiform neurofibromas (PN). Magnetic resonance imaging (MRI) with volumetric analysis and 18-fluorodeoxyglucose-positron emission tomography (FDG-PET) were utilized to monitor symptomatic nodular lesions.

PROCEDURE

Patients with NF1 and PN on a NCI natural history trial were monitored for total body tumor volume (TTV) using volumetric MRI. FDG-PET was performed in individuals with a nodular well-demarcated lesion ≥3 cm if they were growing, painful, or there was a prior history of MPNST (target lesions). Asymptomatic nodular lesions were evaluated as non-target lesions.

RESULTS

Fifteen patients (8m, 7f) median age of 18.3 years (range, 10-45 years) had a single target and non-target (n = 46) nodular lesions identified on MRI. Target lesions arose within (n = 8) or outside (n = 3) a PN, and all but 1 had increased FDG uptake. FDG uptake was increased in non-target lesions but to a lesser degree. FDG uptake in the surrounding PN was low, similar to background activity. Pathologic evaluation performed in 11 patients demonstrated neurofibroma (n = 6), atypical neurofibroma (n = 2) and malignancy (n = 3).

CONCLUSIONS

Nodular target lesions identified on MRI in individuals with NF1 and PN demonstrate increased FDG uptake similar to MPNST, but may be benign on biopsy. Nodular target lesions may be at greater risk for malignant transformation, but their biologic and clinical behavior has not been well studied. Careful longitudinal evaluation will be required to better understand the malignant potential of these lesions.

Evaluation and treatment of fever in the non-neutropenic child with cancer

PURPOSE

To document the current approach to the evaluation and treatment of febrile non-neutropenic children with cancer by surveying American Society of Pediatric Hematology/Oncology (ASPHO) members.

METHODS

Five hundred ninety-five ASPHO members were sent questionnaires polling their current practices in the evaluation and treatment of clinically stable, febrile (oral temperature of 38 degrees C x2, or >or=38.3 degrees C), non-neutropenic (absolute neutrophil count > 500/microL) pediatric cancer patients who have no identifiable bacterial infection. Patients were assigned to one of four groups based on the presence or absence of a central venous catheter (CVC) and no source (NS) or presumed viral source (VS) for fever.

RESULTS

Three hundred sixteen ASPHO members (53%) responded and 300 questionnaires were evaluable. If a CVC was present, respondents universally drew blood cultures (99% NS, 96% VS) from the CVC, but only one third drew peripheral blood cultures (33% NS, 29% VS). If a CVC was not present, the majority of respondents (80% NS, 61% VS) drew peripheral cultures. ASPHO members started empiric antibiotics more frequently in patients with a CVC (69% NS, 55% VS) than in patients without a CVC (33% NS, 23% VS). Most did not admit these patients to the hospital (40% CVC and NS, 33% CVC and VS, 22% no CVC and NS, 19% no CVC and VS). ASPHO members with more years of experience were more likely to obtain peripheral blood cultures if a CVC was present and to admit a patient without a CVC.

CONCLUSIONS

Nearly all respondents obtained a blood culture from the CVC in the initial assessment of the febrile, non-neutropenic patient with a CVC, but other evaluation and management practices varied considerably.

Effect of probenecid on ventricular cerebrospinal fluid methotrexate pharmacokinetics after intralumbar administration in nonhuman primates

PURPOSE

Intrathecal methotrexate (MTX) achieves high concentrations in the cerebrospinal fluid (CSF) following intralumbar administration. However, peak ventricular CSF MTX concentrations are highly variable and are < 10% of those achieved with intraventricular dosing. The objectives of this study were to evaluate the effect of intralumbar and intravenous probenecid on ventricular CSF MTX concentrations after intralumbar administration of MTX, and to compare the pharmacokinetics of MTX after intralumbar and intraventricular administration.

METHODS

Nonhuman primates (Macaca mulatta) with permanently implanted catheters in the lateral and fourth ventricles received 0.5 mg intraventricular (lateral ventricle) MTX, or 0.5 mg intralumbar MTX with and without intralumbar or intravenous probenecid. Animals were kept prone for 1 h after MTX administration, and ventricular CSF was sampled up to 48 h from a fourth ventricular Ommaya reservoir. MTX concentrations were measured using the dihydrofolate reductase enzyme inhibition assay. Area under the ventricular CSF MTX concentration-time curve (AUC) was used as a measure of MTX exposure.

RESULTS

Peak ventricular CSF MTX concentrations and AUCs were highly variable after intralumbar MTX administration. Ventricular CSF MTX AUCs increased by a mean of 3.2-fold after the addition of intralumbar probenecid. Intravenous administration of probenecid did not result in an increase in ventricular CSF MTX AUCs. Asymptomatic pleocytosis was observed in all animals after intralumbar probenecid administration. Ventricular CSF MTX concentrations and AUCs were less variable after intraventricular administration of MTX.

CONCLUSION

The administration of intralumbar but not intravenous probenecid increases the ventricular CSF MTX exposure after intralumbar MTX administration.

Effect of an inhibitor of protein kinase C on human polymorphonuclear leukocyte degranulation

The protein kinase C inhibitor C-I reduced superoxide production by human neutrophils in response to phorbol myristate acetate by greater than 50%. In contrast to its effects in oxidative metabolism, 100 microM C-I caused minimal inhibition (5-18%) of lysozyme release in response to phorbol myristate acetate. Enzyme release produced by the formylated oligopeptide FMLP was enhanced by 23-54% in neutrophils pretreated with 100 microM C-I. These findings suggest that protein kinase C activation is not required for phorbol myristate acetate induced enzyme release. Enhancement of FMLP stimulated degranulation by C-I suggests that protein kinase C activation may have inhibitory effects on the release of granule enzymes by human neutrophils.

Clinical evaluation of moxalactam: evidence of decreased efficacy in gram-positive aerobic infections

Moxalactam was used as initial, empirical therapy in 69 patients with a variety of serious bacterial infections, 32% of which were accompanied by bacteremia. Overall, the success rate was 83% and drug-related adverse effects were minimal. The drug was less efficacious in infections caused by aerobic gram-positive pathogens than it was in those caused by gram-negative pathogens. The following gram-positive organisms were associated with special problems during moxalactam therapy: Streptococcus pneumoniae (development of meningitis and a relapse of pneumonia with a more resistant strain), Staphylococcus epidermidis (in vivo emergence of moxalactam resistance, and the enterococci (failure of therapy and a fatal superinfection. Moxalactam performed well in infections caused by most gram-negative organisms, including aminoglycoside-resistant strains, but the previously reported emergence of gram-negative bacillary resistance to moxalactam during therapy was reconfirmed in our series with Serratia marcescens. The use of moxalactam in the treatment of gram-negative meningitis was further supported by a patient with meningitis-ventriculitis caused by Bacteroides fragilis who was cured with moxalactam after failure on chloramphenicol.