The Childhood Cancer Data Initiative: Using the Power of Data to Learn From and Improve Outcomes for Every Child and Young Adult With Pediatric Cancer.

Data-driven basic, translational, and clinical research has resulted in improved outcomes for children, adolescents, and young adults (AYAs) with pediatric cancers. However, challenges in sharing data between institutions, particularly in research, prevent addressing substantial unmet needs in children and AYA patients diagnosed with certain pediatric cancers. Systematically collecting and sharing data from every child and AYA can enable greater understanding of pediatric cancers, improve survivorship, and accelerate development of new and more effective therapies.

A Phase II Trial of Guadecitabine in Children and Adults with SDH-Deficient GIST, Pheochromocytoma, Paraganglioma, and HLRCC-Associated Renal Cell Carcinoma.

Purpose: Succinate dehydrogenase (dSDH)-deficient tumors, including pheochromocytoma/paraganglioma, hereditary leiomyomatosis and renal cell cancer-associated renal cell carcinoma (HLRCC-RCC), and gastrointestinal stromal tumors (GIST) without KIT or platelet-derived growth factor receptor alpha mutations are often resistant to cytotoxic chemotherapy, radiotherapy, and many targeted therapies. We evaluated guadecitabine, a dinucleotide containing the DNA methyltransferase inhibitor decitabine, in these patient populations.

Patients And Methods: Phase II study of guadecitabine (subcutaneously, 45 mg/m2/day for 5 consecutive days, planned 28-day cycle) to assess clinical activity (according to RECISTv.

Recent Advances in Pediatric Cancer Research.

Over the past few years, the field of pediatric cancer has experienced a shift in momentum, and this has led to new and exciting findings that have relevance beyond pediatric malignancies. Here we present the current status of key aspects of pediatric cancer research. We have focused on genetic and epigenetic drivers of disease, cellular origins of different pediatric cancers, disease models, the tumor microenvironment, and cellular immunotherapies.

SARC025 arms 1 and 2: A phase 1 study of the poly(ADP-ribose) polymerase inhibitor niraparib with temozolomide or irinotecan in patients with advanced Ewing sarcoma.

Background: In preclinical Ewing sarcoma (ES) models, poly(adenosine diphosphate ribose) polymerase (PARP) inhibitors were identified as a potential therapeutic strategy with synergy in combination with cytotoxic agents. This study evaluated the safety and dosing of the PARP1/2 inhibitor niraparib (NIR) with temozolomide (TMZ; arm 1) or irinotecan (IRN; arm 2) in patients with pretreated ES.

Methods: Eligible patients in arm 1 received continuous NIR daily and escalating TMZ (days 2-6 [D2-6]) in cohort A.

LRRC15 antibody-drug conjugates show promise as osteosarcoma therapeutics in preclinical studies.

Background: Osteosarcoma (OS), the most common bone tumor in children and adolescents, has high rates of metastasis leading to poor survival. Leucine-rich repeat containing 15 (LRRC15), a transmembrane protein whose expression is modulated by TGFβ, was recently shown to be highly expressed on the surface of OS tumor cells. Here, we evaluate a novel antibody-drug conjugate (ADC) targeting LRRC15 in OS human cell lines and murine xenografts.

Molecular mechanisms of Guadecitabine induced FGFR4 down regulation in alveolar rhabdomyosarcomas.

Fibroblast growth factor receptor 4 (FGFR4) aberrant expression and activity have been linked to the pathogenesis of a variety of cancers including rhabdomyosarcomas (RMS). We found that treatment of alveolar rhabdomyosarcoma (aRMS) cells with Guadecitabine (SGI-110), a next-generation DNA methyltransferase inhibitor (DNMTi), resulted in a significant reduction of FGFR4 protein levels, 5 days post treatment. Chromatin immunoprecipitation-sequencing (ChIP-seq) in aRMS cells revealed attenuation of the H3K4 mono-methylation across the FGFR4 super enhancer without changes in tri-methylation of either H3K4 or H3K27.

Results of a Randomized, Double-Blinded, Placebo-Controlled, Phase 2.5 Study of Saracatinib (AZD0530), in Patients with Recurrent Osteosarcoma Localized to the Lung.

Purpose: Osteosarcoma is a rare cancer and a third of patients who have completed primary treatment will develop osteosarcoma recurrence. The Src pathway has been implicated in the metastatic behavior of osteosarcoma; about 95% of samples examined express Src or have evidence of downstream activation of this pathway. Saracatinib (AZD0530) is a potent and selective Src kinase inhibitor that was evaluated in adults in Phase 1 studies.

EWS-FLI1-regulated Serine Synthesis and Exogenous Serine are Necessary for Ewing Sarcoma Cellular Proliferation and Tumor Growth.

Despite a growing body of knowledge about the genomic landscape of Ewing sarcoma, translation of basic discoveries into targeted therapies and significant clinical gains has remained elusive. Recent insights have revealed that the oncogenic transcription factor EWS-FLI1 can impact Ewing sarcoma cellular metabolism, regulating expression of 3-phosphoglycerate dehydrogenase (PHGDH), the first enzyme in serine synthesis. Here, we have examined the importance of serine metabolism in Ewing sarcoma tumorigenesis and evaluated the therapeutic potential of targeting serine metabolism in preclinical models of Ewing sarcoma.

Targeting Hippo-Dependent and Hippo-Independent YAP1 Signaling for the Treatment of Childhood Rhabdomyosarcoma.

Rhabdomyosarcoma is the most common childhood soft-tissue sarcoma, yet patients with metastatic or recurrent disease continue to do poorly, indicating a need for new treatments. The SRC family tyrosine kinase YES1 is upregulated in rhabdomyosarcoma and is necessary for growth, but clinical trials using single agent dasatinib, a SRC family kinase inhibitor, have failed in sarcomas. YAP1 (YES-associated protein) is highly expressed in rhabdomyosarcoma, driving growth and survival when the upstream Hippo tumor suppressor pathway is silenced, but efforts to pharmacologically inhibit YAP1 have been unsuccessful.

CDK9 Blockade Exploits Context-dependent Transcriptional Changes to Improve Activity and Limit Toxicity of Mithramycin for Ewing Sarcoma.

There is a need to develop novel approaches to improve the balance between efficacy and toxicity for transcription factor-targeted therapies. In this study, we exploit context-dependent differences in RNA polymerase II processivity as an approach to improve the activity and limit the toxicity of the EWS-FLI1-targeted small molecule, mithramycin, for Ewing sarcoma. The clinical activity of mithramycin for Ewing sarcoma is limited by off-target liver toxicity that restricts the serum concentration to levels insufficient to inhibit EWS-FLI1.

A Phase II Trial of Vandetanib in Children and Adults with Succinate Dehydrogenase-Deficient Gastrointestinal Stromal Tumor.

Purpose: Gastrointestinal stromal tumors (GIST) are resistant to cytotoxic chemotherapy and radiotherapy. Most GIST in children are wild-type for and (WT GIST) and deficient in expression of succinate dehydrogenase (dSDH GIST). We tested the activity of vandetanib, an oral small-molecule inhibitor of VEGFR2, EGFR, and RET, in patients with dSDH GIST.

Targeting Glycolysis through Inhibition of Lactate Dehydrogenase Impairs Tumor Growth in Preclinical Models of Ewing Sarcoma.

Altered cellular metabolism, including an increased dependence on aerobic glycolysis, is a hallmark of cancer. Despite the fact that this observation was first made nearly a century ago, effective therapeutic targeting of glycolysis in cancer has remained elusive. One potentially promising approach involves targeting the glycolytic enzyme lactate dehydrogenase (LDH), which is overexpressed and plays a critical role in several cancers.

Targeting Sporadic and Neurofibromatosis Type 1 (NF1) Related Refractory Malignant Peripheral Nerve Sheath Tumors (MPNST) in a Phase II Study of Everolimus in Combination with Bevacizumab (SARC016).

Purpose: There are no known effective medical treatments for refractory MPNST. Inactivation of the NF1 tumor suppressor in MPNST results in upregulation of mTOR (mammalian target of rapamycin) signaling and angiogenesis, which contributes to disease progression. We conducted a phase II study for patients (pts) with refractory MPNST combining everolimus (10 mg PO once daily) with bevacizumab (10 mg/kg IV every 2 weeks) to determine the clinical benefit rate (CBR) (complete response, partial response (PR), or stable disease (SD) ≥ 4 months).

Insights into pediatric rhabdomyosarcoma research: Challenges and goals.

Overall survival rates for pediatric patients with high-risk or relapsed rhabdomyosarcoma (RMS) have not improved significantly since the 1980s. Recent studies have identified a number of targetable vulnerabilities in RMS, but these discoveries have infrequently translated into clinical trials. We propose streamlining the process by which agents are selected for clinical evaluation in RMS.

Glutamine synthetase is necessary for sarcoma adaptation to glutamine deprivation and tumor growth.

Despite a growing body of knowledge about the genomic landscape and molecular pathogenesis of sarcomas, translation of basic discoveries into targeted therapies and significant clinical gains has remained elusive. Renewed interest in altered metabolic properties of cancer cells has led to an exploration of targeting metabolic dependencies as a novel therapeutic strategy. In this study, we have characterized the dependency of human pediatric sarcoma cells on key metabolic substrates and identified a mechanism of adaptation to metabolic stress by examining proliferation and bioenergetic properties of rhabdomyosarcoma and Ewing sarcoma cells under varying concentrations of glucose and glutamine.

Corrigendum: Positively selected enhancer elements endow osteosarcoma cells with metastatic competence.

This corrects the article DOI: 10.1038/nm.4475.

Positively selected enhancer elements endow osteosarcoma cells with metastatic competence.

Metastasis results from a complex set of traits acquired by tumor cells, distinct from those necessary for tumorigenesis. Here, we investigate the contribution of enhancer elements to the metastatic phenotype of osteosarcoma. Through epigenomic profiling, we identify substantial differences in enhancer activity between primary and metastatic human tumors and between near isogenic pairs of highly lung metastatic and nonmetastatic osteosarcoma cell lines.

SARC006: Phase II Trial of Chemotherapy in Sporadic and Neurofibromatosis Type 1 Associated Chemotherapy-Naive Malignant Peripheral Nerve Sheath Tumors.

Background: Worse chemotherapy response for neurofibromatosis type 1- (NF1-) associated compared to sporadic malignant peripheral nerve sheath tumors (MPNST) has been reported.

Methods: We evaluated the objective response (OR) rate of patients with AJCC Stage III/IV chemotherapy-naive NF1 MPNST versus sporadic MPNST after 4 cycles of neoadjuvant chemotherapy, 2 cycles of ifosfamide/doxorubicin, and 2 cycles of ifosfamide/etoposide. A Simon optimal two-stage design was used (target response rate 40%).

Matrix Screen Identifies Synergistic Combination of PARP Inhibitors and Nicotinamide Phosphoribosyltransferase (NAMPT) Inhibitors in Ewing Sarcoma.

Although many cancers are showing remarkable responses to targeted therapies, pediatric sarcomas, including Ewing sarcoma, remain recalcitrant. To broaden the therapeutic landscape, we explored the response of Ewing sarcoma cell lines against a large collection of investigational and approved drugs to identify candidate combinations. Drugs displaying activity as single agents were evaluated in combinatorial (matrix) format to identify highly active, synergistic drug combinations, and combinations were subsequently validated in multiple cell lines using various agents from each class.

A phase I/II trial and pharmacokinetic study of mithramycin in children and adults with refractory Ewing sarcoma and EWS-FLI1 fusion transcript.

Purpose: In a preclinical drug screen, mithramycin was identified as a potent inhibitor of the Ewing sarcoma EWS-FLI1 transcription factor. We conducted a phase I/II trial to determine the dose-limiting toxicities (DLT), maximum tolerated dose (MTD), and pharmacokinetics (PK) of mithramycin in children with refractory solid tumors, and the activity in children and adults with refractory Ewing sarcoma.

Patients And Methods: Mithramycin was administered intravenously over 6 h once daily for 7 days for 28 day cycles.

Surveillance Recommendations for Children with Overgrowth Syndromes and Predisposition to Wilms Tumors and Hepatoblastoma.

A number of genetic syndromes have been linked to increased risk for Wilms tumor (WT), hepatoblastoma (HB), and other embryonal tumors. Here, we outline these rare syndromes with at least a 1% risk to develop these tumors and recommend uniform tumor screening recommendations for North America. Specifically, for syndromes with increased risk for WT, we recommend renal ultrasounds every 3 months from birth (or the time of diagnosis) through the seventh birthday.

Surgical Management of Wild-Type Gastrointestinal Stromal Tumors: A Report From the National Institutes of Health Pediatric and Wildtype GIST Clinic.

Purpose Wild-type gastrointestinal stromal tumors (WT-GISTs) that lack KIT or PDGFRA mutations represent a unique subtype of GIST that predominantly affects children. We sought to determine the effect on event-free survival (EFS) of staging variables, extent of resection, and repeat resection of tumors. Methods In 2008, a WT-GIST clinic was established at the National Cancer Institute, allowing the development of a large clinical database.