PDF file - 104K, Supplementary Table S1. Vismodegib Dosing Strategy Supplementary Table S2. Commonly Reported Adverse Events According to Grade Supplementary Table S3. Pharmacokinetics of Unbound Vismodegib in Pediatric Patients with Medulloblastoma

PDF file - 156K, Supplementary Fig. S1. Concentration-time plots of the first 72 hours after administration of the first vismodegib dose during Course 1 to the patients in the initial cohort: 6 received 85 mg/m2 (Figure A & B), and 7 received 170 mg/m2 (Figure C &D). Plasma concentrations of total vismodegib (A, C) and unbound vismodegib (B, D) were measured. Supplementary Fig S2. The relation between total vismodegib plasma concentrations and alpha-1-acid glycoprotein (AAGP) plasma concentrations in pediatric patients. The scatter plot includes all data from patients treated in this study. The solid line represents the best-fit line from linear regression analysis (R2= 0.38).

Background The study aimed to evaluate whether simplified chemotherapy followed by dose-reduced irradiation was effective for treating patients (ages 3-21 years) with localized germinoma. The primary endpoint was 3-year progression-free survival (PFS) rate. Methods Patients with a complete response to chemotherapy with carboplatin and etoposide received 18 Gy WVI + 12 Gy boost to the tumor bed. Patients with partial response proceeded to 24 Gy WVI + 12 Gy. Longitudinal cognitive functioning was evaluated prospectively on ALTE07C1 and was a primary study aim. Results One hundred and fifty-one patients were enrolled; 137 were eligible. Among 90 evaluable patients, 74 were treated with 18 Gy and 16 with 24 Gy WVI. The study failed to demonstrate noninferiority of the 18 Gy WVI regimen compared to the design threshold of 95% 3-year PFS rate, where, per design, patients who could not be assessed for progression at 3 years were counted as failures. The Kaplan-Meier (KM)-based 3-year PFS estimates were 94.5 +/- 2.7% and 93.75 +/- 6.1% for the 18 Gy and 24 Gy WVI cohorts, respectively. Collectively, estimated mean IQ and attention/concentration were within normal range. A lower mean attention score was observed at 9 months for patients treated with 24 Gy. Acute effects in processing speed were observed in the 18 Gy cohort at 9 months which improved at 30-month assessment. Conclusions While a failure according to the prospective statistical noninferiority design, this study demonstrated high rates of chemotherapy responses, favorable KM-based PFS and OS estimates in the context of reduced irradiation doses and holds promise for lower long-term morbidities for patients with germinoma.

The purpose of this work was to determine the effect of resistance exercise (RE)-induced hormonal changes on the satellite cell (SC) myogenic state in response to muscle damage. Untrained men ( n = 10, 22 ± 3 yr) and women ( n = 9, 21 ± 4 yr) completed 2 sessions of 80 unilateral maximal eccentric knee extensions followed by either an upper body RE protocol (EX) or a 20-min rest (CON). Muscle samples were collected and analyzed for protein content of Pax7, MyoD, myogenin, cyclin D1, and p21 before (PRE), 12 h, and 24 h after the session was completed. Serum testosterone, growth hormone, cortisol, and myoglobin concentrations were analyzed at PRE, post-damage, immediately after (IP), and 15, 30, and 60 min after the session was completed. Testosterone was significantly ( P < 0.05) higher immediately after the session in EX vs. CON for men. A significant time × sex × condition interaction was found for MyoD with an increase in EX (men) and CON (women) at 12 h. A significant time × condition interaction was found for Pax7, with a decrease in EX and increase in CON at 24 h. A significant time effect was found for myogenin, p21, and cyclin D1. Myogenin and p21 were increased at 12 and 24 h, and cyclin D1 was increased at 12 h. These results suggest that the acute RE-induced hormonal response can be important for men to promote SC proliferation after muscle damage but had no effect in women. Markers of SC differentiation appeared unaffected by the hormonal response but increased in response to muscle damage.

The heat shock protein (HSP) response is critical to the cellular stress response. Circulating, extracellular stress‐inducible HSP72 is known to respond to exercise‐heat stress, but little is known about other, constitutively expressed and fundamental members of the HSP family. The aim of this study was to investigate the extracellular HSP27, HSP60, and HSP90α response during a prolonged cycling event in hot and humid conditions. Seventy‐six subjects (mean±SD: age, 51.64±10.47 years; height, 176.44±6.85 cm; mass, 86.78±13.93 kg) were recruited at the Hotter'n Hell 100 mile cycling event in Wichita Falls, Texas. Blood and urine samples, as well as data on body weight and gastrointestinal temperature (TGI) were recorded before (pre) and after (post) the event. Plasma was isolated from blood samples, stored at −80°C, and later analyzed with StressMarq Biosciences ELISAs for HSP27, HSP60, and HSP90α concentrations. Student's t‐test was used to test for significant differences of means. TGI significantly increased from pre to post (pre: 37.14±0.55 °C; post: 38.12±0.79 °C; p<0.05). HSP27 and HSP90α were both significantly elevated post race (pre27: 2.73±0.51 ng × mL−1; post27: 3.46±0.73 ng × mL−1; pre90α: 18.03±3.27 ng × mL−1; post90α: 21.53±4.84 ng × mL−1; p < 0.05). However, there was no significant difference in HSP60 plasma concentration from pre to post (pre: 44.05±7.38; post: 43.65±6.81; p=0.77). In conclusion, significant increases in circulating HSP27 and HSP90α suggest that chaperones required for thermotolerance and protein degradation or folding during heat stress increase in extracellular compartments post exercise‐heat stress. However, our data suggest that chaperones specifically involved in mitochondrial protein assembly or molecular danger signals like HSP60 are not elevated in blood fractions. Ongoing work will characterize cellular expression of these proteins in circulating peripheral blood mononuclear cells.Support or Funding InformationNew investigator start‐up, McNair Scholar ProgramThis abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Intracranial germ cell tumors represent 3-5% of pediatric CNS tumors. Non-germinomatous germ cell tumors (NGGCT) have worse outcomes compared to germinomas, however, improved survivals were achieved on COG ACNS0122 utilizing a combination of chemotherapy and craniospinal irradiation (CSI). Since CSI is associated with significant late effects, a Phase 2 study was undertaken to determine whether irradiation could be reduced without impacting survival in a subgroup of NGGCT patients. Patients with localized disease who achieved a complete (CR) or partial response (PR) to chemotherapy were eligible for reduced irradiation to 30.6Gy whole ventricular field (WVI) and 54Gy tumor-bed boost as compared to 36Gy CSI plus tumor-bed boost as used on ACNS0122. Between 5/2012 and 11/2016, 107 eligible patients were accrued. Median age was 11 years (range: 4-22) and 75% were male. Tumor location was pineal in 58, suprasellar in 37, ventricular in 6 and bifocal in 6 patients. Sixty-six patients achieved CR/PR post-induction and received reduced irradiation. The 2-year progression-free survival (PFS) was 89% (95% CI: 81%-97%) and overall survival was 92% (95% CI: 86%- 99%). Eight patients progressed; seven had a distant relapse (outside the irradiation field) and one patient had a local plus distant relapse. Alpha-fetoprotein and beta-human chorionic gonadotropin levels were not associated with PFS. There were no unexpected treatment-related adverse events or deaths. Although these survival data are encouraging, distant relapses noted in all of the patients who progressed are concerning. Longer follow-up of the ACNS1123 cohort may better inform our recommendations in the future.

BackgroundWe conducted a phase II study of oral capecitabine rapidly disintegrating tablets given concurrently with radiation therapy (RT) to assess progression-free survival (PFS) in children with newly diagnosed diffuse intrinsic pontine gliomas (DIPG). Patients and methodsChildren 3-17 years with newly diagnosed DIPG were eligible. Capecitabine, 650mg/m(2)/dose BID (maximum tolerated dose [MTD] in children with concurrent radiation), was administered for 9weeks starting the first day of RT. Following a 2-week break, three courses of capecitabine, 1,250mg/m(2)/dose BID for 14 days followed by a 7-day rest, were administered. As prospectively designed, 10 evaluable patients treated at the MTD on the phase I trial were included in the phase II analyses. The design was based on comparison of the PFS distribution to a contemporary historical control (n=140) with 90% power to detect a 15% absolute improvement in the 1-year PFS with a type-1 error rate, =0.10. ResultsForty-four patients were evaluable for the phase II objectives. Capecitabine and RT was well tolerated with low-grade palmar plantar erythrodyesthesia, increased alanine aminotransferase, cytopenias, and vomiting the most commonly reported toxicities. Findings were significant for earlier progression with 1-year PFS of 7.21% (SE=3.47%) in the capecitabine-treated cohort versus 15.59% (SE=3.05%) in the historical control (P=0.007), but there was no difference for overall survival (OS) distributions (P=0.30). Tumor enhancement at diagnosis was associated with shorter PFS and OS. Capecitabine was rapidly absorbed and converted to its metabolites. ConclusionCapecitabine did not improve the outcome for children with newly diagnosed DIPG.

We evaluated circulating levels of immunosuppressive regulatory T cells (Tregs) and other lymphocyte subsets in patients with newly diagnosed medulloblastoma (MBL) undergoing surgery compared to a control cohort of patients undergo craniectomy for correction of Chiari malformation (CM) and further determined the impact of standard irradiation and chemotherapy on this cell population.

Background Activation of the mitogen-activated protein kinase pathway is important for growth of pediatric low-grade gliomas (LGGs). The aim of this study was to determine the recommended phase II dose (RP2D) and the dose-limiting toxicities (DLTs) of the MEK inhibitor selumetinib in children with progressive LGG. Methods Selumetinib was administered orally starting at 33 mg/m2/dose b.i.d., using the modified continual reassessment method. Pharmacokinetic analysis was performed during the first course. BRAF aberrations in tumor tissue were determined by real-time polymerase chain reaction and fluorescence in situ hybridization. Results Thirty-eight eligible subjects were enrolled. Dose levels 1 and 2 (33 and 43 mg/m2/dose b.i.d.) were excessively toxic. DLTs included grade 3 elevated amylase/lipase (n = 1), headache (n = 1), mucositis (n = 2), and grades 2-3 rash (n = 6). At dose level 0 (25 mg/m2/dose b.i.d, the RP2D), only 3 of 24 subjects experienced DLTs (elevated amylase/lipase, rash, and mucositis). At the R2PD, the median (range) area under the curve (AUC0-∞) and apparent oral clearance of selumetinib were 3855 ng*h/mL (1780 to 7250 ng × h/mL) and 6.5 L × h-1 × m-2 (3.4 to 14.0 L × h-1 × m-2), respectively. Thirteen of 19 tumors had BRAF abnormalities. Among the 5 (20%) of 25 subjects with sustained partial responses, all at the RP2D, 4 had BRAF aberrations, 1 had insufficient tissue. Subjects received a median of 13 cycles (range: 1-26). Fourteen (37%) completed all protocol treatment (26 cycles [n = 13], 13 cycles [n = 1]) with at least stable disease; 2-year progression-free survival at the RP2D was 69 ± SE 9.8%. Conclusion Selumetinib has promising antitumor activity in children with LGG. Rash and mucositis were the most common DLTs.

BACKGROUND:p53 is a promising target in human cancer. p28 is a cell-penetrating peptide that preferentially enters cancer cells and binds to both wild-type and mutant p53 protein, inhibiting COP1-mediated ubiquitination and proteasomal degradation. This results in increased levels of p53, which induces cell cycle arrest at G2/M. We conducted a phase I study to determine the maximum-tolerated dose (MTD) and describe the dose-limiting toxicities (DLTs) and pharmacokinetics (PKs) of p28 in children.METHODS:Children aged 3-21 years with recurrent or progressive central nervous system tumors were eligible. Intravenous p28 was administered 3 times weekly for 4 consecutive weeks of a 6-week cycle at 4.16 mg/kg/dose (the adult recommended phase II dose) using a rolling-6 study design. Expression status of p53 was characterized by immunohistochemistry, and serum PK parameters were established on the second dose.RESULTS:Of the 18 eligible patients enrolled in the study, 12 completed the DLT monitoring period and were evaluable for toxicity. p28 was well-tolerated; 7 participants received ≥2 courses, and the most common adverse event attributed to the drug was transient grade 1 infusion-related reaction. PK analysis revealed a profile similar to adults; however, an increased area under the curve was observed in pediatric patients. High p53 expression in tumor cell nuclei was observed in 6 of 12 available tissue samples. There were no objective responses; 2 participants remained stable on the study for >4 cycles.CONCLUSIONS:This phase I study demonstrated that p28 is well-tolerated in children with recurrent CNS malignancies at the adult recommended phase II dose.

Telomerase activation is critical in many cancers including central nervous system (CNS) tumors. Imetelstat is an oligonucleotide that binds to the template region of the RNA component of telomerase, inhibiting its enzymatic activity. We conducted an investigator-sponsored molecular biology (MB) and phase II study to estimate inhibition of tumor telomerase activity and sustained responses by imetelstat in children with recurrent CNS malignancies. In the MB study, patients with recurrent medulloblastoma, high-grade glioma (HGG) or ependymoma undergoing resection received one dose of imetelstat as a 2-h intravenous infusion at 285 mg/m 2 , 12–24 h before surgery. Telomerase activity was evaluated in fresh tumor from surgery. Post-surgery and in the phase II study, patients received imetelstat IV (days 1 and 8 q21-days) at 285 mg/m 2 . Imetelstat pharmacokinetic and pharmacodynamic studies were performed. Of two evaluable patients on the MB trial, intratumoral telomerase activity was inhibited by 95 % compared to baseline archival tissue in one patient and was inevaluable in one patient. Forty-two patients (40 evaluable for toxicity) were enrolled: 9 medulloblastomas, 18 HGG, 4 ependymomas, 9 diffuse intrinsic pontine gliomas. Most common grade 3/4 toxicities included thrombocytopenia (32.5 %), lymphopenia (17.5 %), neutropenia (12.5 %), ALT (7.5 %) and AST (5 %) elevation. Two patients died of intratumoral hemorrhage secondary to thrombocytopenia leading to premature study closure. No objective responses were observed. Telomerase inhibition was observed in peripheral blood mononuclear cells (PBMCs) for at least 8 days. Imetelstat demonstrated intratumoral and PBMC target inhibition; the regimen proved too toxic in children with recurrent CNS tumors.

Background. p53 is a promising target in human cancer. p28 is a cell-penetrating peptide that preferentially enters cancer cells and binds to both wild-type and mutant p53 protein, inhibiting COP1-mediated ubiquitination and proteasomal degradation. This results in increased levels of p53, which induces cell cycle arrest at G(2)/M. We conducted a phase 1 study to determine the maximum-tolerated dose (MTD) and describe the dose-limiting toxicities (DLTs) and pharmacokinetics (PKs) of p28 in children.Methods. Children aged 3-21 years with recurrent or progressive central nervous system tumors were eligible. Intravenous p28 was administered 3 times weekly for 4 consecutive weeks of a 6-week cycle at 4.16 mg/kg/dose (the adult recommended 2 dose) using a rolling-6 study design. Expression status of p53 was characterized by immunohistochemistry, and serum PK parameters were established on the second dose.Results. Of the 18 eligible patients enrolled in the study, 12 completed the DLT monitoring period and were evaluable for toxicity. p28 was well-tolerated; 7 participants received >= 2 courses, and the most common adverse event attributed to the drug was transient grade 1 infusion-related reaction. PK analysis revealed a profile similar to adults; however, an increased area under the curve was observed in pediatric patients. High p53 expression in tumor cell nuclei was observed in 6 of 12 available tissue samples. There were no objective responses; 2 participants remained stable on the study for >4 cycles.Conclusions. This 1 study demonstrated that p28 is well-tolerated in children with recurrent CNS malignancies at the adult recommended phase 2 dose.

Background The outcomes with high‐risk central nervous system (CNS) embryonal tumors remain relatively poor despite aggressive treatment. The purposes of this study using postirradiation myeloablative chemotherapy with autologous hematopoietic stem cell rescue (ASCR) were to document feasibility and describe toxicities of the regimen, establish the appropriate dose of thiotepa, and estimate the overall survival (OS) and event‐free survival (EFS). Procedure The Children's Cancer Group conducted this pilot study in children and adolescents with CNS embryonal tumors. The treatment consisted of induction chemotherapy to mobilize hematopoietic stem cells, chemoradiotherapy, and myeloablative consolidation chemotherapy with ASCR. Results The study accrued 25 subjects in 40 months and was closed early due to toxicity, namely, veno‐occlusive disease (VOD) of the liver, more recently termed sinusoidal obstructive syndrome (SOS). Of 24 eligible subjects, three of 11 (27%) receiving thiotepa Dose Level 1 (150 mg/m 2 /day × 3 days) and three of 12 (25%) receiving de‐escalated Dose Level 0 (100 mg/m 2 /day × 3 days) experienced VOD/SOS. One additional subject experienced toxic death attributed to septic shock; postmortem examination revealed clinically undiagnosed VOD/SOS. The 2‐year EFS and OS were 54 ± 10% and 71 ± 9%, respectively. The 5‐year EFS and OS were 46 ± 11% and 50 ± 11%. Conclusions The treatment regimen was deemed to have an unacceptable rate of VOD/SOS. There was complete recovery in all six cases. The overall therapeutic strategy using a regimen less likely to cause VOD/SOS may merit further evaluation for the highest risk patients.

Sunitinib malate is a small multi‐targeted tyrosine kinase inhibitor that inhibits vascular endothelial growth factor receptor (VEGFR), platelet‐derived growth factor receptor (PDGFR) and stem cell factor receptor (KIT), which are highly expressed by some high‐grade brain tumors. We conducted a phase II study to estimate the efficacy and further characterize the pharmacokinetics of sunitinib in pediatric patients with recurrent or refractory high‐grade glioma (Stratum A) or ependymoma (Stratum B). This was a prospective, multicenter Phase II trial conducted through the Children's Oncology Group (ClinicalTrials.gov Identifier NCT01462695). Sunitinib, 15 mg/m2, was orally administered once daily for 4 weeks every 6 weeks. The safety and tolerability of sunitinib, an estimate of progression‐free survival (PFS), analyses of sunitinib pharmacokinetics (PK) and pharmacodynamics modulation of plasma VEGF and VEGFR2 were also assessed. Thirty eligible patients (17 patients on Stratum A, 13 patients on Stratum B) were enrolled and 29 patients were evaluable for response. Sunitinib was reasonably well tolerated in children with recurrent ependymoma or high‐grade glioma. Most adverse events were of mild‐to‐moderate severity and manageable with supportive treatment. While there was a statistically significant modulation of plasma VEGFR2 with sunitinib exposure, there were no sustained tumor responses. Both strata were closed at time of planned interim analysis as there was not sufficient efficacy associated with sunitinib in children with recurrent brain tumors. Sunitinib was well tolerated in children and young adults with recurrent high‐grade glioma or ependymoma but had no single agent objective antitumor activity in these patients.

OBJECT The impact of central pathology review on outcome has been described in pediatric patients with high-grade glioma (HGG). The objective of this report was to analyze the impact of the central pathology review on outcome in the subgroup of patients with institutional diagnosis of HGG of the spinal cord enrolled in the Children's Cancer Group 945 cooperative study. METHODS Five neuropathologists centrally reviewed the pathology of the 18 patients with HGG of the spinal cord who were enrolled in the study. These reviews were independent, and reviewers were blinded to clinical history and outcomes. A consensus diagnosis was established for each patient, based on the outcome of the review. RESULTS Of 18 patients, only 10 were confirmed to have HGG on central review. At a median follow-up of 12 years, event-free and overall survival for all 18 patients was 43.2% ± 13.3% and 50% ± 13.4%, respectively. After central review, 10-year event-free and overall survival for confirmed HGGs and discordant diagnoses was 30% ± 12.5% versus 58.3% ± 18.8% (p = 0.108) and 30% ± 12.5% versus 75% ± 14.2% (p = 0.0757), respectively. CONCLUSIONS The level of discordant diagnoses in children and adolescents with institutional diagnosis of HGG of the spinal cord was 44% in this experience. However, there was no significant difference in outcome between patients with confirmed and discordant diagnosis. This group of tumor deserves a specific attention in future trials.

pre-irradiation chemotherapy may allow for a safe