Pediatric HCT in Florida (2014 -2016): A report from the FPBCC

FPBCC was formed in 2018 by five pediatric transplant programs in Florida. One of the key objectives of the consortium is to provide outcome analyses by combining HCT data from all the participating centers in order to identify areas for improvement. In this first FPBCC landscape report we describe the patient and transplant characteristics of pediatric patients undergoing first allo and auto HCT between 2014 and 2016 in Florida. The source of data was eDBtC of the CIBMTR. Over the span of 3 years, a total of 230 pediatric patients underwent allo-HCT and 104 underwent auto-HCT at the participating centers. The most significant predictor of survival in allo-HCT recipients with malignant disorders was the degree of HLA- match, while in the recipients of allo-HCT with non-malignant disorders the predictors of survival included age, donor relationship and degree of HLA match. Our analyses identified the need to improve reporting of primary cause of death and improve on donor selection process given that the degree of HLA match remains the most important predictor of survival. This first FPBCC-wide review describes the trends in pediatric HCT activity between 2014 and 2016 among the participating centers in Florida and confirms feasibility of using eDBtC data platform and collaborative approach in order to identify areas for improvement in outcomes.

A phase I study of panobinostat in children with relapsed and refractory hematologic malignancies

Background: Panobinostat demonstrates activity against pediatric cancers in vitro. A phase I trial in children with refractory hematologic malignancies was conducted. Study design: The trial evaluated two schedules of oral panobinostat using 3 + 3 dose escalations in 28-day cycles. For children with leukemia, panobinostat was given once daily three days a week each week at 24, 30 and 34 mg/m2/day. For children with lymphoma, panobinostat was given once daily three days a week every other week at 16, 20 and 24 mg/m2/day. Cerebrospinal fluid (CSF) from Day 29 of the first cycle, when available, was evaluated for PK. The study was registered on clinicaltrials.gov (NCT01321346) Results: Twenty-two subjects enrolled with leukemia. Five enrolled at dose level 1, 6 at dose level 2, and 11 at dose level 3. There was one dose limiting toxicity (DLT) in the leukemia arm at dose level 3 (Grade 4 hypertriglyceridemia), but no maximum tolerated dose (MTD) was identified. No subjects required removal from protocol therapy for QTc prolongation. PK studies were available in 11 subjects with similar exposure in children as in adults. Four Day 29 CSF specimens were found to have panobinostat levels below the lower limit of quantification. Five subjects with lymphoma were enrolled and received study drug, and 4 were evaluable for DLT. A DLT was reported (Grade 3 enteritis) on the lymphoma arm. Conclusions: Panobinostat was tolerated in heavily pretreated pediatric subjects. Gastrointestinal effects were observed on this study. There were no cardiac findings. There were no responses.

Combining 2-deoxy-D-glucose with fenofibrate leads to tumor cell death mediated by simultaneous induction of energy and ER stress

Unregulated growth and replication as well as an abnormal microenvironment, leads to elevated levels of stress which is a common trait of cancer. By inducing both energy and endoplasmic reticulum (ER) stress, 2-Deoxy-glucose (2-DG) is particularly well-suited to take advantage of the therapeutic window that heightened stress in tumors provides. Under hypoxia, blocking glycolysis with 2-DG leads to significant lowering of ATP resulting in energy stress and cell death in numerous carcinoma cell types. In contrast, under normoxia, 2-DG at a low-concentration is not toxic in most carcinomas tested, but induces growth inhibition, which is primarily due to ER stress. Here we find a synergistic toxic effect in several tumor cell lines in vitro combining 2-DG with fenofibrate (FF), a drug that has been safely used for over 40 years to lower cholesterol in patients. This combination induces much greater energy stress than either agent alone, as measured by ATP reduction, increased p-AMPK and downregulation of mTOR. Inhibition of mTOR results in blockage of GRP78 a critical component of the unfolded protein response which we speculate leads to greater ER stress as observed by increased p-eIF2α. Moreover, to avoid an insulin response and adsorption by the liver, 2-DG is delivered by slow-release pump yielding significant anti-tumor control when combined with FF. Our results provide promise for developing this combination clinically and others that combine 2-DG with agents that act synergistically to selectively increase energy and ER stress to a level that is toxic to numerous tumor cell types.

Abstract CT145: A phase I window, dose escalating and safety trial of Metformin in combination with induction chemotherapy (VPLD)in relapsed/refractory acute lymphoblastic leukemia: NCT01324180

Background: Relapsed Acute Lymphoblastic Leukemia (ALL) remains a major cause of cancer-related deaths in children. We identified the AMP activated protein kinase (AMPK) as a potential target for ALL therapy due to its regulatory effects on the unfolded protein response (UPR), leading to increased vulnerability of ALL cells to endoplasmic reticulum (ER) stress inducers. In vitro, metformin leads to ALL cell death via AMPK-mediated inhibition of the UPR. Methods: Metformin was administered twice daily continuously on a 28 day cycle in addition to the Vincristine, Dexamethasone, PEG-Asparaginase and Doxorubicin (VPLD) systemic regimen and CNS-directed therapy in pediatric patients with relapsed/refractory ALL. Metformin doses were increased in a standard 3+3 phase I design with three dose levels evaluated, 666, 1,000 and 1,333 mg/m2/day. Pharmacokinetic (PK) and pharmacodynamic (PD) evaluation of the AMPK and ER stress/UPR pathways were ascertained on days 1 and 7, and treatment response was assessed on day 29. Results: Fourteen patients were enrolled, 11 evaluable. DL3 was the maximum administered dose with 2 related DLT’s of diarrhea and acidosis. A single DLT of hypoglycemia and acidosis during an episode of sepsis was observed in DL2. Infectious SAE’s occurred in 7 patients. Two patients had posterior reversible encephalopathy syndrome; both died of disease progression within 30 days of coming off study. A single patient had stable disease, 2 had a partial response, and 3 achieved a complete response. PK studies demonstrated levels within the therapeutic range for patients with diabetes, and PD evaluation showed induction of ER stress and inhibition of the UPR. Conclusions: This trial has been completed. We found induction of ER stress with inhibition of UPR consistent with that observed in vitro leading to metformin-induced apoptosis. The chemotherapeutic backbone was tolerable and the combination with metformin yielded responses in a heavily pretreated population. Toxicities attributable to metformin occurred in all dose levels, but DLT’s were only observed in dose levels above the standard dosing for diabetes. Clinical trial information: NCT01324180

Citation Format: Matteo Trucco, Julio Barredo, John Goldberg, Gregory Hale, Jonathan Gill, Bhuvana Setty, Tiffany Smith, Jae Lee, Damon Reed. A phase I window, dose escalating and safety trial of Metformin in combination with induction chemotherapy (VPLD)in relapsed/refractory acute lymphoblastic leukemia: NCT01324180 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr CT145. doi:10.1158/1538-7445.AM2017-CT145

Controversies in the management of central nervous system leukemia

The central nervous system (CNS) has long been recognized as a site, indeed a sanctuary, for leukemic cells. Although few (<5%) patients with acute lymphoblastic leukemia (ALL) actually present with overt CNS leukemia, without prophylactic CNS-directed treatment, over 50% will develop CNS disease. However, with modern CNS prophylaxis, the incidence of CNS relapse has been reduced to 6% or less. Although great progress has been made, we continue to struggle with management of CNS leukemia. This commentary will address issues of CNS leukemia treatment at diagnosis and at relapse. Topics that will be addressed include (1) CNS 2 status at diagnosis-definition and treatment; (2) CNS leukemia at diagnosis--treatment with radiation therapy; (3) isolated relapse of leukemia in the CNS--treatment of early and late relapse; and (4) opportunities for future research in CNS relapse of ALL.

Renal kallikrein: a risk marker for nephropathy in children with sickle cell disease

OBJECTIVE

Although improvements in the management of sickle cell disease (SCD) have increased patient survival into adulthood, morbidity and mortality from end-organ damage remain major concerns. One of the most serious complications of SCD is renal failure, affecting about 20% of patients. The clinical manifestations of sickle cell nephropathy (SCN) involve changes in glomerular ultrastructure, albuminuria, and a progressive decline in glomerular hemodynamics. The mechanisms or factors that promote SCN are not fully elucidated. In the present study, the role of renal kallikrein as a risk marker for promoting SCN was explored in a cross-sectional study.

METHODS AND RESULTS

We measured the urinary excretion rate of active kallikrein in 73 children with sickle cell anemia (hemoglobin SS, SC, or S thalassemia) and in 30 control healthy African American children. The findings demonstrated that a significant difference in the excretion rate of log kallikrein in male versus female patients with SCD, P<0.0078 was observed. In children with SCD, cross-sectional analysis revealed a positive and significant correlation between the excretion rate of active kallikrein and log albumin excretion rate (AER), P<0.0088. Regression analysis also determined that the excretion rate of active kallikrein negatively correlates with hemoglobin in children with SCD, P<0.0096. In addition, an inverse relationship between log AER and hemoglobin was observed in male patients with SCD, P<0.0143. In children with SCD, cross-sectional analysis revealed a positive and significant correlation between log AER and age, suggesting age as a risk marker for AER in SCD. In multivariate regression analysis, our findings demonstrate a strong association between log AER and age and log kallikrein in children with SCD. About 20% of the variability in log AER in SCD patients is influenced by age and 6% is influenced by log kallikrein, P<0.0001 and P<0.02, respectively.

CONCLUSIONS

These findings provide the first evidence that the excretion rate of active kallikrein is positively and independently correlated with log AER in children with SCD, and suggest that kallikrein could be a marker for progressive nephropathy. Longitudinal studies are essential to address this issue.

Management of paranasal sinus malignancy

Malignancies of the nasal cavity and paranasal sinuses represent a wide spectrum of histologies, tissues of origin, and anatomic primary sites. The inherent difficulty in generalizing treatment approaches is obvious, given the numerous variables associated with the broadly-based term, paranasal sinus malignancy (PNSCa). Nevertheless, the majority of epithelial and salivary malignancies of this region (ie, squamous cell carcinoma, adenocarcinoma, adenoid cystic carcinoma, sinonasal undifferentiated carcinoma, and esthesioneuroblastoma) require surgical intervention as part of any treatment regimen. Recent trends have broadened the indications for chemotherapeutic and radiotherapeutic options in the management of advanced PNSCa. Nonepithelial malignancies, including the wide variety of sarcomas arising in this region, most commonly require multimodality treatment including chemotherapy, radiation, and/or surgery for definitive treatment. Moreover, the proximity of the nasal cavity and paranasal sinuses to structures including the orbit, dura, brain, cranial nerves, and carotid arteries mandates careful radiologic and neurologic evaluations throughout the course of the disease. Surgical advances now permit complex tumor removal and reconstruction surrounding these structures resulting in functional and cosmetic improvements when compared to earlier techniques. However, additional clinical trials are necessary to systematically evaluate the locoregional control, organ-preservation strategies, and survival related to the variety of treatments currently available.

Improved survival of children with isolated CNS relapse of acute lymphoblastic leukemia: a pediatric oncology group study

PURPOSE

Isolated meningeal relapse in children with acute lymphoblastic leukemia (ALL) usually has been followed by bone marrow relapse and limited survival. The purpose of this study was to prevent marrow relapse by administering intensive therapy before delayed craniospinal radiation.

PATIENTS AND METHODS

Eighty-three patients with ALL in first bone marrow remission with an isolated CNS relapse were treated with systemic chemotherapy known to enter into the CSF and intrathecal chemotherapy for 6 months. Craniospinal irradiation (24 Gy cranial/15 Gy spinal) was then administered, followed by 1.5 years of maintenance chemotherapy.

RESULTS

All 83 patients achieved a second remission. The 4-year event-free survival (EFS) rate was 71.1% +/- 5.3%. There was a fourfold increased risk of relapse for children whose initial remission was less than 18 months. The 4-year EFS rate for patients with a first complete remission >/= 18 months was 83.3% +/- 5.3%, and for those with a first complete remission less than 18 months, it was 46.2% +/- 10.2% (P =.0002.) There was a low incidence of neurologic toxicity and an unexpectedly high rate of allergic reactions to L-asparaginase. Five patients developed secondary malignancies: two with acute nonlymphoblastic leukemia during therapy, one with myelodysplasia after therapy, and two with brain tumors 1.5 to 2 years after cessation of therapy.

CONCLUSION

For children with ALL and an isolated CNS relapse, treatment that delays definitive craniospinal irradiation by 6 months to allow for more intensive systemic and intrathecal chemotherapy results in better EFS than has been previously reported. Using this approach, the long-term prognosis for children with first complete remission >/= 18 months is comparable to that at the time of original diagnosis of ALL.

Effects of antisense-based folypoly-gamma-glutamate synthetase down-regulation on reduced folates and cellular proliferation in CCRF-CEM cells

The effect of down-regulation of folylpoly-gamma-glutamate synthetase (FPGS) activity on intracellular reduced folate accumulation and cellular proliferation was examined, using an inducible antisense expression system in the human T-lymphoblastic leukemia cell line CCRF-CEM. FPGS catalyzes the addition of gamma-glutamyl residues to natural folates and classical antifolates, which results in their enhanced cellular retention and increased cytotoxicity. As such, this enzyme has become a focus as a potential anticancer drug target. However, direct evidence to support this concept has been elusive. Hence, a study was undertaken using an antisense-based expression system to down-regulate FPGS activity. This inducible expression system was used to demonstrate that lower FPGS activity can lead to substantially lower intracellular folate content, which coincides with suppression of thymidylate synthesis and inhibition of cellular proliferation.

Myelodysplasia associated with Turner syndrome

PURPOSE

This study reports the association of myelodysplasia with Turner syndrome.

PATIENT AND METHODS

An 11-year-old girl with Turner syndrome was found to have mild macrocytic anemia that persisted during 2 years.

RESULTS

Examination of the bone marrow revealed dyserythropoietic features with multinucleation consistent with refractory anemia. Levels of hemoglobin F were also markedly elevated (57%). She also had transient neutropenia and thrombocytopenia, as well as abnormal platelet function studies. The hematopoietic abnormalities were mild and may have been missed were she not followed for her hypertension and aortic coarctation.

CONCLUSIONS

Myelodysplastic syndromes in children are frequently associated with chromosomal abnormalities, but an association with Turner syndrome has not been previously described. This could be due to the fact that mild hematopoietic abnormalities in these patients may not be investigated.

Neurologic complications following bone marrow transplantation for sickle cell disease

A boy with sickle cell anemia underwent bone marrow transplantation (BMT). He was normal on neurological examination, but had radiologic evidence of an old left frontal lobe infarct, multiple cerebral vascular stenoses and moyamoya collaterals. After BMT he developed seizures with extension of the infarct and subarachnoid hemorrhage. One year later angiography revealed worsening stenosis of the M1 segments of both middle cerebral arteries. At that time an increase in von Willebrand's factor with decreased large molecular weight multimers (LvWF) was observed. We speculate that LvWF dependent, shear-induced platelet aggregation, together with endothelial damage may have contributed to the development of neurologic complications in this patient.

Pleuropulmonary blastoma: a marker for familial disease

OBJECTIVE

To catalog and evaluate patterns of disease in families of children with pleuropulmonary blastoma (PPB).

METHODS

Data have been collected since 1988 on 45 children with PPB and their families. All pathologic materials were centrally reviewed. Preliminary molecular genetic analyses were performed when possible.

RESULTS

In 12 of 45 patients, an association was found between PPB and other dysplasias, neoplasias, or malignancies in the patients with or in their young relatives. The diseases found to be associated with PPB include other cases of PPB, pulmonary cysts, cystic nephromas, sarcomas, medulloblastomas, thyroid dysplasias and neoplasias, malignant germ cell tumors, Hodgkin disease, leukemia, and Langerhans cell histiocytosis. Abnormalities of the p53 tumor suppressor gene, Wilms tumor suppressor gene (WT1), and the putative second genetic locus for Wilms tumor (WT2) were not found in preliminary investigations.

CONCLUSIONS

The occurrence of PPB appears to herald a constitutional and heritable predisposition to dysplastic or neoplastic disease in approximately 25% of cases. All patients with PPB and their families should be investigated carefully. Further research of this new family cancer syndrome may provide insight into the genetic basis of these diseases.

Bone marrow transplantation for sickle cell anemia

PURPOSE

To investigate the role of bone marrow transplantation in patients with severe sickle cell anemia (SCA).

PATIENTS AND METHODS

We have designed a protocol for selecting patients with severe SCA who may benefit from bone marrow transplantation (BMT). On the basis of this protocol, a girl 3 9/12 years of age who had severe recurrent pain crises and splenic dysfunction received a BMT from her brother, who is homozygous for hemoglobin A.

RESULTS

Transplantation resulted in prompt engraftment, followed by durable hematologic and immunologic reconstitution with donor cells. One year after BMT, the patient continued to do well. She did not experience any graft versus host disease, her growth velocity increased, and recovery of splenic function was demonstrated. Since undergoing BMT, she has not experienced any painful crises.

CONCLUSIONS

Bone marrow transplantation is an effective therapeutic modality that should be considered in patients with severe SCA.

A dideazatetrahydrofolate analogue lacking a chiral center at C-6, N-[4-[2-(2-amino-3,4-dihydro-4-oxo-7H-pyrrolo[2,3-d]pyrimidin-5- yl)ethyl]benzoyl]-L-glutamic acid, is an inhibitor of thymidylate synthase

N-[4-[2-(2-Amino-3,4-dihydro-4-oxo-7H-pyrrolo[2,3-d]pyrimidin-5- yl)ethyl]benzoyl]-L-glutamic acid (15), prepared in five steps from 2-pivaloyl-7-deazaguanine, has been found to be an antitumor agent with its primary site of action at thymidylate synthase rather than purine synthesis. This compound appears to be a promising candidate for clinical evaluation.

Determinants of antifolate cytotoxicity: folylpolyglutamate synthetase activity during cellular proliferation and development

Previous studies have documented the metabolism of a broad range of folate antimetabolites to polyglutamate derivatives by the enzyme folylpoly-gamma-glutamate synthetase (FPGS). The activity of the more recently developed classes of antifolates directed against thymidylate synthase and de novo purine synthesis is sufficiently dependent on polyglutamation that these compounds should be specifically cytotoxic to any normal or malignant proliferating cell expressing this enzyme. We have studied the patterns of expression of FPGS in mammalian cells and tissues during rapid growth, growth arrest, differentiation, and embryonic development. During embryogenesis in the rat, FPGS levels in liver and brain were higher during the period of proliferative activity and then dropped to a level characteristic of the adult organs. However, the levels in liver were substantially higher than those in brain at any given time. This pattern was mimicked in mouse C3H 10T1/2 embryo fibroblast cells, in which FPGS activity decreased after cessation of growth but then remained at a lower steady state level during an extended period of postconfluent culture. Enzyme activity also dropped after the differentiation of human HL-60 promyelocytic leukemia cells. In a human homolog of these experimental systems, FPGS levels were below the limits of detection in circulating mature human hematopoietic cells of the granulocytic, lymphoblastic, and erythrocytic lineages. In striking contrast, substantial levels of FPGS were found in circulating lymphoblasts from eight patients with acute lymphoblastic leukemia. The levels of FPGS found in these transformed stem cells would help to explain the sensitivity of many acute lymphoblastic leukemias to folate antimetabolites. We concluded that expression of FPGS is regulated by at least two mechanisms, one of which is linked to proliferation and the other of which controls enzyme levels after differentiation and is tissue specific.

Hereditary erythrocyte adenylate kinase deficiency: a defect of multiple phosphotransferases?

Adenylate kinase (AK) modulates the interconversion of adenine nucleotides (AMP + adenosine triphosphate----2 ADP). We evaluated the fifth kindred with hereditary erythrocyte (RBC) AK deficiency. The proband had chronic hemolytic anemia. Her RBC had undetectable AK activity when measured spectrophotometrically, whereas those of her parents had half-normal AK activity. AK electrophoresis showed only AK-1 in the parents. The activities of pyruvate kinase and phosphoribosylpyrophosphate synthetase were decreased given the young age of the proband's RBC. Despite the absence of spectrophotometric AK activity, the proband's RBC were able to incorporate 14C-adenine into 14C-adenine nucleotides at 50% of the rate expected for her young RBC population, suggesting the possibility of an alternative pathway for the formation of ADP from AMP. Normal hemolysate had AMP:guanosine triphosphate (GTP) phosphotransferase activity, which produced ADP at 8% to 9% of the rate of AK (6.8 +/- 0.8 IU/mL RBC). AMP:GTP phosphotransferase activity was not detectable in the proband's or parent's hemolysates. These additional biochemical defects in the AK-deficient RBC further support the concept that AK deficiency per se may not cause hemolytic anemia. We propose that defects occur in multiple phosphotransferases in the AK-deficient RBC and that these other biochemical defects may produce deleterious lesions that promote the shortened RBC survival in AK deficiency.

A microassay for mammalian folylpolyglutamate synthetase

A new assay for the enzyme folylpoly-gamma-glutamate synthetase (FPGS) that offers significant advantages over other published procedures has been developed. This assay is based on the addition of high specific activity [3H]glutamic acid to (6-S)-tetrahydrofolate followed by trapping of the labeled tetrahydropteroyldiglutamate product as a covalently bound macromolecular complex by the addition of formaldehyde, fluorodeoxyuridylate, and pure bacterial thymidylate synthase. This complex is then separated from excess labeled glutamic acid by centrifugal elution of a 1-ml Sephadex G-50 column. The assay was found to be useful for the measurement of FPGS on small tissue samples and is amenable with the assay of FPGS in cell sonicates. Typically, blank values of 100-200 cpm are seen with a signal normally more than 10 times higher. Analysis of 20-30 samples can be accomplished in less than 90 min. As a result, this assay has proven useful for detection of enzyme in elution fractions from chromatographic columns.