Search

Supplemental Table 2: List of SNPs analyzed.

Supplemental Table 3. Primer sequences.

Supplemental Table 1: Specimen Characteristics.

Diffuse spinal cord gliomas (SCGs) are rare tumors associated with a high morbidity and mortality that affect both pediatric and adult populations. In this retrospective study, we sought to characterize the clinical, pathological, and molecular features of diffuse SCG in 22 patients with histological and molecular analyses. The median age of our cohort was 23.64 years (range 1-82) and the overall median survival was 397 days. K27M mutation was significantly more prevalent in males compared to females. Gross total resection and chemotherapy were associated with improved survival, compared to biopsy and no chemotherapy. While there was no association between tumor grade, K27M status (p = 0.366) or radiation (p = 0.772), and survival, males showed a trend toward shorter survival. K27M mutant tumors showed increased chromosomal instability and a distinct DNA methylation signature.

Background Activation of the mammalian target of rapamycin (mTOR) pathway is observed in neurofibromatosis type 1 (NF1) associated low-grade gliomas (LGGs), but agents that inhibit this pathway, including mTOR inhibitors, have not been studied in this population. We evaluate the efficacy of the orally administered mTOR inhibitor everolimus for radiographically progressive NF1-associated pediatric LGGs. Methods Children with radiologic-progressive, NF1-associated LGG and prior treatment with a carboplatin-containing chemotherapy were prospectively enrolled on this phase II clinical trial to receive daily everolimus. Whole blood was analyzed for everolimus and markers of phosphatidylinositol-3 kinase (PI3K)/mTOR pathway inhibition. Serial MRIs were obtained during treatment. The primary endpoint was progression-free survival at 48 weeks. Results Twenty-three participants (median age, 9.4 y; range, 3.2–21.6 y) were enrolled. All participants were initially evaluable for response; 1 patient was removed from study after development of a malignant peripheral nerve sheath tumor. Fifteen of 22 participants (68%) demonstrated a response, defined as either shrinkage (1 complete response, 2 partial response) or arrest of tumor growth (12 stable disease). Of these, 10/15 remained free of progression (median follow-up, 33 mo). All remaining 22 participants were alive at completion of therapy. Treatment was well tolerated; no patient discontinued therapy due to toxicity. Pharmacokinetic parameters and pre-dose concentrations showed substantial between-subject variability. PI3K/mTOR pathway inhibition markers demonstrating blood mononuclear cell mTOR pathway inactivation was achieved in most participants. Conclusion Individuals with recurrent/progressive NF1-associated LGG demonstrate significant disease stability/shrinkage during treatment with oral everolimus with a well-tolerated toxicity profile. Everolimus is well suited for future consideration as upfront or combination therapy in this patient population.

The incidence of intracranial germ cell tumors (iGCT) is much lower in European and North American (E&NA) than in Asian population. However, E&NA cooperative groups have simultaneously developed with success treatment strategies with specific attention paid to long-term sequelae. Neurological sequelae may be reduced by establishing a diagnosis with an endoscopic biopsy and/or cerebrospinal fluid (CSF) and/or serum analysis, deferring the need to perform a radical surgery. Depending on markers and/or histological characteristics, patients are treated as either germinoma or non-germinomatous germ cell tumors (NGGCT). Metastatic disease is defined by a positive CSF cytology and/or distant drops in craniospinal MRI. The combination of surgery and/or chemotherapy and radiation therapy is tailored according to grouping and staging. With more than 90% 5-year event-free survival (EFS), localized germinomas can be managed without aggressive surgery, and benefit from chemotherapy followed by whole ventricular irradiation with local boost. Bifocal germinomas are treated as non-metastatic entities. Metastatic germinomas may be cured with craniospinal irradiation. With a 5-year EFS over 70%, NGGCT benefit from chemotherapy followed by delayed surgery in case of residual disease, and some form of radiotherapy. Future strategies will aim at decreasing long-term side effects while preserving high cure rates.

BACKGROUND: Central nervous system (CNS) germinomas are treatment-sensitive tumors with excellent survival outcomes. Current treatment strategies combine chemotherapy with radiotherapy (RT) in order to reduce the field and dose of RT. Germinomas originating in the basal ganglia/thalamus (BGTGs) have proven challenging to treat given their rarity and poorly defined imaging characteristics. Craniospinal (CSI), whole brain (WBI), whole ventricle (WVI), and focal RT have all been utilized; however, the best treatment strategy remains unclear. METHODS: Retrospective multi-institutional analysis has been conducted across 18 institutions in four countries. RESULTS: For 43 cases of non-metastatic BGTGs, the 5- and 10-year event-free survival (EFS) were 85.8% and 81.0%, respectively, while the 5- and 10-year overall survival (OS) were 100%, and 95.5%, respectively (one patient fatality from unrelated cause). Median RT doses were as follows: CSI: 2250 cGy/cGy(RBE) (1980 to 2400 cGy/cGy[RBE]), WBI: 2340 (1800 to 3000 cGy/cGy[RBE]), WVI: 2340 cGy/cGy(RBE) (1800 to 2550 cGy/cGy[RBE]), focal: 3600 cGy (3060 to 5400 cGy). Thirty-eight patients (90.5%) received chemotherapy. There was no statistically significant difference in the EFS based on initial field extent (p=0.84). Nevertheless, no relapses were reported in patients who received CSI or WBI. Chemotherapy alone had significantly inferior EFS compared to combined therapy (p=0.0092), but patients were salvageable with RT. CONCLUSION: Patients with BGTGs have excellent outcomes and RT proved to be an integral component of the treatment plan. This group of patients should be included in future prospective clinical trials and the best RT field should be investigated further.

Inhibition of mTORC1 signaling has been shown to diminish growth of meningiomas and schwannomas in preclinical studies, and clinical data suggest that everolimus, an orally administered mTORC1 inhibitor, may slow tumor progression in a subset of patients with neurofibromatosis type 2 (NF2) with vestibular schwannoma. To assess the pharmacokinetics, pharmacodynamics, and potential mechanisms of treatment resistance, we performed a presurgical (phase 0) clinical trial of everolimus in patients undergoing elective surgery for vestibular schwannoma or meningiomas. Eligible patients with meningioma or vestibular schwannoma requiring tumor resection enrolled on study received everolimus 10 mg daily for 10 days immediately prior to surgery. Everolimus blood levels were determined immediately before and after surgery. Tumor samples were collected intraoperatively. Ten patients completed protocol therapy. Median pre- and postoperative blood levels of everolimus were found to be in a high therapeutic range (17.4 ng/mL and 9.4 ng/mL, respectively). Median tumor tissue drug concentration determined by mass spectrometry was 24.3 pg/mg (range, 9.2–169.2). We observed only partial inhibition of phospho-S6 in the treated tumors, indicating incomplete target inhibition compared with control tissues from untreated patients (P = 0.025). Everolimus led to incomplete inhibition of mTORC1 and downstream signaling. These data may explain the limited antitumor effect of everolimus observed in clinical studies for patients with NF2 and will inform the design of future preclinical and clinical studies targeting mTORC1 in meningiomas and schwannomas.

PURPOSE Patients with neurofibromatosis type 1 (NF1) frequently develop plexiform neurofibromas (PNs), which can cause significant morbidity. We performed a phase II trial of the MAPK/ERK kinase inhibitor, mirdametinib (PD-0325901), in patients with NF1 and inoperable PNs. The primary objective was response rate based on volumetric magnetic resonance imaging analysis. METHODS Inclusion criteria included age ≥ 16 years and a PN that was either progressive or causing significant morbidity. First-dose pharmacokinetics were performed. Patients completed patient-reported outcome measures. Patients received mirdametinib by mouth twice a day at 2 mg/m2/dose (maximum dose = 4 mg twice a day) in a 3-week on/1-week off sequence. Each course was 4 weeks in duration. Evaluations were performed after four courses for the first year and then after every six courses. Patients could receive a maximum of 24 total courses. RESULTS Nineteen patients were enrolled, and all 19 received mirdametinib. The median age was 24 years (range, 16-39 years); the median baseline tumor volume was 363.8 mL (range, 3.9-5,161 mL). Eight of the 19 patients (42%) achieved a partial response of the target PN by course 12, and 10 (53%) had stable disease. One patient (5%) developed progressive disease at course 8. Significant and durable decreases were observed in pain ratings. CONCLUSION To our knowledge, this analysis represents the first characterization of the activity and pharmacokinetics of mirdametinib in patients with NF1 and PNs and is the first published response study for MAPK/ERK kinase inhibitors in adults with NF1 and PNs. Mirdametinib given at 2 mg/m2/dose (maximum dose, 4 mg) twice daily in a 3-week on/1-week off sequence resulted in a 42% partial response rate with preliminary evidence of reduction in pain.

Data for visual acuity (VA) after treatment of neurofibromatosis type 1-associated optic pathway gliomas (NF1-OPGs) are limited. We retrospectively collected VA, converted to logMAR, before and after targeted therapy with everolimus for NF1-OPG, and compared to radiologic outcomes (14/18 with NF1-OPG, 25 eyes [three without quantifiable vision]). Upon completion of treatment, VA was stable in 19 eyes, improved in four eyes, and worsened in two eyes; visual and radiologic outcomes were discordant. In summary, the majority of children with NF1-OPG exhibited stabilization of their VA after everolimus treatment. A larger, prospective study will help delineate visual outcomes after targeted therapy.

Background To evaluate efficacy, pharmacokinetics (PK) and pharmacodynamics of single-agent everolimus in pediatric patients with radiographically progressive low-grade glioma (LGG). Methods Everolimus was administered at 5 mg/m2 once daily as a tablet or liquid for a planned 48-week duration or until unacceptable toxicity or disease progression. Patients with neurofibromatosis type 1 were excluded. PK and pharmacodynamic endpoints were assessed in consenting patients. Results Twenty-three eligible patients (median age 9.2 years) were enrolled. All patients received prior chemotherapy (median number of prior regimens two) and/or radiotherapy (two patients). By week 48, two patients had a partial response, 10 stable disease, and 11 clinical or radiographic progression; two discontinued study prior to 1 year (toxicity: 1, physician determination: 1). With a median follow up of 1.8 years (range 0.2-6.7 years), the 2-, 3-, and 5-year progression-free survivals (PFS) were 39 ± 11%, 26 ± 11%, and 26 ± 11%, respectively; two patients died of disease. The 2-, 3-, and 5-year overall survival (OS) were all 93 ± 6%. Grade 1 and 2 toxicities predominated; two definitively related grade 3 toxicities (mucositis and neutropenia) occurred. Grade 4 elevation of liver enzymes was possibly related in one patient. Predose blood levels showed substantial variability between patients with 45.5% below and 18.2% above the target range of 5-15 ng/mL. Pharmacodynamic analysis demonstrated significant inhibition in phospho-S6, 4E-BP1, and modulation of c-Myc expression. Conclusion Daily oral everolimus provides a well-tolerated, alternative treatment for multiple recurrent, radiographically progressive pediatric LGG. Based on these results, everolimus is being investigated further for this patient population.

Data for visual acuity (VA) after treatment of neurofibromatosis type 1-associated optic pathway gliomas (NF1-OPGs) is limited. We retrospectively collected VA, converted to logMAR, before and after targeted therapy with everolimus for NF1-OPG, and compared to radiologic outcomes (14/18 with NF1-OPG, 25 eyes [3 without quantifiable vision]). Upon completion of treatment, VA was stable in 19 eyes, improved in 4 eyes, and worse in 2 eyes; visual and radiologic outcome were discordant. In summary, the majority of children with NF1-OPG exhibited stabilization of their VA after everolimus treatment. A larger, prospective study will help delineate visual outcomes after targeted therapy.

ObjectiveTo determine a suitable outcome measure for assessing muscle strength in neurofibromatosis (NF) type 1 and NF2 clinical trials, we evaluated the intraobserver reliability of handheld dynamometry (HHD) and developed consensus recommendations for its use in NF clinical trials.MethodsPatients ≥5 years of age with weakness in at least 1 muscle group by manual muscle testing (MMT) were eligible. Maximal isometric muscle strength of a weak muscle group and the biceps of the dominant arm was measured by HHD. An average of 3 repetitions per session was used as an observation, and 3 sessions with rest period between each were performed on the same day by a single observer. Intrasession and intersession intraclass correlation coefficients (ICCs) and coefficients of variation (CVs) were calculated to assess reliability and measurement error.ResultsTwenty patients with NF1 and 13 with NF2 were enrolled; median age was 12 years (interquartile range [IQR] 9–17 years) and 29 years (IQR 22–38 years), respectively. By MMT, weak muscle strength ranged from 2−/5 to 4+/5. Biceps strength was 5/5 in all patients. Intersession ICCs for the weak muscles were 0.98 and 0.99 in the NF1 and NF2 cohorts, respectively, and for biceps were 0.97 and 0.97, respectively. The median CVs for average session strength were 5.4% (IQR 2.6%–7.3%) and 2.9% (IQR 2.0%–6.2%) for weak muscles and biceps, respectively.ConclusionHHD performed by a trained examiner with a well-defined protocol is a reliable technique to measure muscle strength in NF1 and NF2. Recommendations for strength testing in NF1 and NF2 trials are provided.

Craniopharyngiomas are benign brain tumors that can often be cured surgically. A small fraction of unresectable tumors can progress and cause significant morbidity and even death. Unfortunately, WNT activated tumors lack clinically-validated targeted therapies in the pediatric population. Herein, we describe a patient with a multiply recurrent adamantinomatous craniopharyngioma with WNT activation. We utilized the MEK inhibitor binimetinib with noted interval decrease in tumor size. This demonstrates the possible utility of MEK inhibitors in WNT activated craniopharyngiomas.

Background “Head Start” III, was a prospective clinical trial using intensive induction followed by myeloablative chemotherapy and autologous hematopoietic cell rescue (AuHCR) to either avoid or reduce the dose/volume of irradiation in young children with medulloblastoma. Methods Following surgery, patients received 5 cycles of induction followed by myeloablative chemotherapy using carboplatin, thiotepa, and etoposide with AuHCR. Irradiation was reserved for children >6 years old at diagnosis or with residual tumor post-induction. Results Between 2003 and 2009, 92 children Conclusion We report excellent survival and preservation of mean IQ and memory for young children with ND medulloblastoma using high-dose chemotherapy, with most patients surviving without irradiation.

Pleomorphic xanthoastrocytoma (PXA) is a rare type of brain tumor that affects children and young adults. Molecular prognostic markers of PXAs remain poorly established. Similar to gangliogliomas, PXAs show prominent immune cell infiltrate, but its composition also remains unknown. In this study, we correlated DNA methylation and BRAF status with clinical outcome and explored the tumor microenvironment. We performed DNA methylation in 21 tumor samples from 18 subjects with a histological diagnosis of PXA. MethylCIBERSORT was used to deconvolute the PXA microenvironment by analyzing the associated immune cell-types. Median age at diagnosis was 16 years (range 7–32). At median follow-up of 30 months, 3-year and 5-year overall survival was 73% and 71%, respectively. Overall survival ranged from 1 to 139 months. Eleven out of 18 subjects (61%) showed disease progression. Progression-free survival ranged from 1 to 89 months. Trisomy 7 and CDKN2A/B (p16) homozygous deletion did not show any association with overall survival (p = 0.67 and p = 0.74, respectively). Decreased overall survival was observed for subjects with tumors lacking the BRAF V600E mutation (p = 0.02). PXAs had significantly increased CD8 T-cell epigenetic signatures compared with previously profiled gangliogliomas (p = 0.0019). The characterization of immune cell-types in PXAs may have implications for future development of immunotherapy.

We present the case of a 22-year-old woman who developed increasing headaches, nausea, and vomiting. Imaging identified a 3 × 3 cm heterogeneously enhancing cystic mass in the posterior III ventricular/pineal region. Pathology review of the initial lesion revealed a highly malignant spindle cell neoplasm composed of round to mostly oval elongated cells with relatively small amounts of cytoplasm arranged in sheets and fascicles with focal storiform pattern. Whole genome methylation analysis through unsupervised clustering with data generated from other primary intracranial tumors and peripheral sarcomas was performed at the German Cancer Research Center (DKFZ) and classified the tumor with the group of alveolar rhabdomyosarcomas (ARMS). Further RNA sequencing revealed an in frame PAX3 (EX 7)-NCOA2 (EX12) fusion confirming the diagnosis. This is the first evidence of occurrence of PAX3-NCOA2 in primary CNS ARMS.

ONC201, an anti-cancer DRD2 antagonist and ClpP agonist, is in Phase II trials for adult H3 K27M-mutant diffuse midline gliomas. The recommended phase 2 dose (RP2D) of 625mg ONC201 once a week has been established as a biologically active dose that is well tolerated in adult and pediatric populations. Radiographic regressions with single agent ONC201 have been reported in recurrent H3 K27M-mutant glioma patients. In another study, twice/week dosing was explored in adult patients and deemed to be safe (no DLTs observed). This warranted exploration of twice/week dosing in pediatric patients and will be discussed in this presentation. This multi-arm, dose-escalation and dose-expansion trial (ONC014; NCT03416530) determined the pediatric RP2D of ONC201 administered once per week and twice per week on two consecutive days. ONC201 was orally administered and scaled by body weight. Dose escalation was performed by a 3 + 3 design beginning with two 125mg capsules less than the adult RP2D equivalent. Twelve children (8 females; 4 males) with H3 K27M-mutant gliomas (pons: 8; thalamus: 2; spinal cord: 2) aged 4-19 years have been treated post-radiation: 3 at dose level -1; 3 at dose level 1; 6 as part of the dose expansion cohort on dose level 2. Median KPS was 90 (range 70-100). One treatment cycle was 21 days (6 doses), which also defined the DLT window. Patients were on-treatment for a median length of 4 cycles (range: 2-11). Twice weekly dosing of ONC201 was tolerated well, as observed with weekly dosing, with no instance of DLT. A total of 4 SAEs were reported, none of which were related to the study drug. The most common AEs (regardless of relatedness) included headache, facial nerve disorder, abducens nerve disorder, nausea, fatigue and ataxia. Additional safety data, PK, and clinical outcomes from this arm will be reported.

BACKGROUND We report the responses, toxicities and long-term outcomes of gemcitabine, paclitaxel and oxaliplatin (GemPOx) regimen administered, in responsive patients, prior to single cycle marrow-ablative chemotherapy (thiotepa, etoposide and carboplatin) with autologous hematopoietic progenitor cell rescue (HDCx+AuHPCR). METHODS Since December 2009, 11 recurrent/refractory patients (10 MMGCT, 1 germinoma; 10 males; mean age 16.5 years, range 7–46 years) have been treated with up to four cycles of gemcitabine (800mg/M2), paclitaxel (170mg/M2) and oxaliplatin (100mg/M2) administered on one day at 14 days intervals. RESULTS All 11 patients were enrolled on a prospective multi-center trial, which was closed in October 2019. Three patients achieved complete remissions (tumor marker and/or imaging studies), five achieved partial remissions, two developed disease progression (PD), and one was withdrawn after one cycle for severe paclitaxel neurotoxicity followed by rapid tumor progression and death. One patient with PD after one cycle had pathologically-confirmed metastatic transformation to pure embryonal rhabdomyosarcoma, and rapidly expired. A second patient, with pure pineal choriocarcinoma, progressed after the second GemPOx cycle, ultimately died of tumor progression. Eight of the 11 responsive patients subsequently underwent HDCx+AuHPCR; five of these received some form of radiotherapy. Seven patients (six MMGCT, one germinoma) are alive and disease-free without recurrence for a mean of 94 months (range 74–118 months) since completion of therapy. CONCLUSION GemPOx is an effective re-induction regimen for patient with recurrent CNS germ cell tumors, with acceptable toxicities; when followed by marrow-ablative chemotherapy and subsequent irradiation/re-irradiation, the regimen produces encouraging long-term disease-free survival.

BACKGROUND Plexiform neurofibromas (PNs) can cause significant morbidity. In this phase 2 study, we assessed imaging and functional outcomes to the MEK-inhibitor Binimetinib in pediatric patients with PNs. METHODS Children (age 1–17 years) with PN that were progressive or causing significant morbidity were eligible. Binimetinib is dosed twice-daily (starting dose of 32mg/m2) for maximum of 24 four-week courses. Participants with partial response (PR; >20% decrease in PN volume on central MRI review) at cycle 12 may stay on therapy. Participants undergo MRI and functional assessments at baseline and after courses 4, 8, 12, 18 and 24. Functional assessments are based on PN location. RESULTS Here we present 1-year response data. Twenty participants (55% male) with median age 12 years (range 2–16 years) enrolled; 19 are evaluable for response. Median baseline tumor volume was 326 ml (range, 8-6661 ml). Fourteen participants (74%) met criteria for PR, with 11 achieving PR by course 5. Median maximal PN volume reduction was 25.5% (range, 9–54%). As of August 2020, 14 participants received at least 12 cycles of Binimetinib; 10 remain on therapy. Off study reasons include treatment associated toxicities (n=2), subject withdrawal (n=2), non-compliance (n=2), prolonged treatment delay (n=1), and lack of response (n=3). Thirteen participants underwent dose reduction. Institution-reported related grade 3 toxicities included dry skin, weight gain, muscle weakness, rash, paronychia, cellulitis, diarrhea, gastric hemorrhage and CPK increase. CONCLUSIONS Binimetinib appears reasonably well-tolerated and shows promising activity in children with NF1-associated PNs. Outcomes on functional improvement will be reported at the meeting.

PURPOSE Bevacizumab treatment at 7.5 mg/kg every 3 weeks results in improved hearing in approximately 35%-40% of patients with neurofibromatosis type 2 (NF2) and progressive vestibular schwannomas (VSs). However, the optimal dose is unknown. In this multicenter phase II and biomarker study, we evaluated the efficacy and safety of high-dose bevacizumab in pediatric and adult patients with NF2 with progressive VS. PATIENTS AND METHODS Bevacizumab was given for 6 months at 10 mg/kg every 2 weeks, followed by 18 months at 5 mg/kg every 3 weeks. The primary end point was hearing response defined by word recognition score (WRS) at 6 months. Secondary end points included toxicity, radiographic response, quality of life (QOL), and plasma biomarkers. RESULTS Twenty-two participants with NF2 (median age, 23 years) with progressive hearing loss in the target ear (median baseline WRS, 53%) were enrolled. Nine (41%) of 22 participants achieved a hearing response at 6 months (1 of 7 children and 8 of 15 adults; P = .08). Radiographic response was seen in 7 (32%) of 22 patients with VS at 6 months (7 of 15 adults and 0 of 7 children; P = .05). Common mild to moderate adverse events included hypertension, fatigue, headache, and irregular menstruation. Improvement in NF2-related QOL and reduction in tinnitus-related distress were reported in 30% and 60% of participants, respectively. Paradoxically, high-dose bevacizumab treatment was not associated with a significant decrease in free vascular endothelial growth factor but was associated with increased carbonic anhydrase IX, hepatocyte growth factor, placental growth factor, stromal cell-derived factor 1α, and basic fibroblast growth factor concentrations in plasma. CONCLUSION High-dose bevacizumab seems to be no more effective than standard-dose bevacizumab for treatment of patients with NF2 with hearing loss. In contrast to adults, pediatric participants did not experience tumor shrinkage. However, adult and pediatric participants reported similar improvement in QOL during induction. Novel approaches using bevacizumab should be considered for children with NF2.

BACKGROUND: Inhibition of mTORC1 signaling has been shown to diminish growth of NF2 deficient tumors in preclinical studies, and clinical data suggest that everolimus, an orally administered mTORC1 inhibitor, may slow tumor progression in a subset of adult and pediatric NF2 patients with VS. To assess the pharmacokinetics, pharmacodynamics and potential mechanisms of treatment resistance, we performed a pre-surgical (“phase 0”) clinical trial of everolimus in patients undergoing surgery for VS or meningiomas. METHODS: Eligible patients with meningioma or VS requiring tumor resection received everolimus 10 mg daily for 10 days immediately prior to surgery. Everolimus blood levels were determined immediately prior to and after surgery. Tumor samples were collected intraoperatively. RESULTS: Ten patients completed protocol therapy, including 5 patients with NF2-related meningioma, 3 patients with sporadic meningioma, and 2 patients with NF2-related VS. Median pre- and post-operative plasma levels of everolimus were found to be in a high therapeutic range (17.4 ng/ml and 9.4 ng/ml, respectively). Median tumor tissue drug concentration determined by mass spectrometry was 24.3 ng/g (range 9.2–169.2), and median tumor tissue to post-operative plasma drug concentration ratio was 0.39. We observed only partial inhibition of phospho-S6 in the treated tumors, indicating incomplete target inhibition compared to matched control tissues from untreated patients (p = 0.005). Consistent with prior observations that inhibition of mTORC1 may lead to MAPK pathway activation through a PI3K-dependent feedback loop, we observed a statistically significant increase of phospho-ERK (p < 0.03) versus untreated controls. CONCLUSIONS: In patients with meningioma or VS, treatment with everolimus leads to incomplete inhibition of mTORC1 signaling and upregulation phospho-ERK. These data may explain the limited anti-tumor effect of everolimus observed in clinical studies for NF2 patients and identify upregulation of phospho-ERK as a likely resistance mechanism that could be addressed with combination therapies.

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.

Pediatric glioblastoma is one of the most common and most deadly brain tumors in childhood. Using an integrative genetic analysis of 53 pediatric glioblastomas and five in vitro model systems, we identified previously unidentified gene fusions involving the MET oncogene in similar to 10% of cases. These MET fusions activated mitogen-activated protein kinase (MAPK) signaling and, in cooperation with lesions compromising cell cycle regulation, induced aggressive glial tumors in vivo. MET inhibitors suppressed MET tumor growth in xenograft models. Finally, we treated a pediatric patient bearing a MET-fusion-expressing glioblastoma with the targeted inhibitor crizotinib. This therapy led to substantial tumor shrinkage and associated relief of symptoms, but new treatment-resistant lesions appeared, indicating that combination therapies are likely necessary to achieve a durable clinical response

H3 K27M-mutant gliomas often manifest as midline gliomas, have a dismal prognosis, and have no effective treatments. ONC201 efficacy has been shown in high-grade glioma preclinical models and durable responses with single agent ONC201 have been reported in adults with recurrent H3 K27M-mutant gliomas. These observations led to a Phase I pediatric clinical trial of ONC201 dosed by body weight. This multi-center, open-label, 3 + 3 dose-escalation and dose-expansion clinical trial (NCT03416530) for H3 K27M-mutant glioma or non-biopsied DIPG has 6 arms: arms A and E determine the RP2D in pediatric post-radiation (recurrent or not-recurrent) H3 K27M-mutant glioma patients with ONC201 administered as an oral capsule as well as a liquid formulation, respectively. Both arms have completed accrual. The study is currently enrolling newly diagnosed DIPG patients to determine the RP2D for ONC201 in combination with radiation (arm B). Dedicated assessment of intratumoral ONC201 concentrations in midline gliomas patients (arm C) and the effects of ONC201 in H3K27M DNA levels in circulating CSF (arm D) are currently enrolling patients. ONC201 as a single agent in patients with progressive H3K27M mutant tumors following irradiation (excluding DIPG/spinal cord tumors) was recently opened (arm F). Once the RP2D is confirmed, there is a dose-expansion cohort to confirm the safety, radiographic efficacy and survival with ONC201. The primary endpoints of arms A, B, and E have been established with the RP2D of 625mg scaled by body weight as a capsule or liquid formulation administered alone or in combination with radiation without incidence of dose-limiting toxicity.

INTRODUCTION Because treatment and clinical management decisions for children with NF1-OPG remain challenging, we sought to establish evidence-based guidelines. We prospectively enrolled children with newly-diagnosed NF1-OPGs, and gathered standardized clinical neuro-oncology and ophthalmology assessments. METHODS Only children with NF1 and newly diagnosed OPGs, confirmed by central review, were eligible. Indications for obtaining the initial MRI, as well as factors associated with the decision to treat with chemotherapy or observe without treatment, were obtained. Quantitative visual acuity (VA), other ophthalmic features, and imaging were captured at standard time points. Goal enrollment is 250 subjects. RESULTS One-hundred thirty-three children (52% female) from 20 institutions met inclusion criteria, and were included in this preliminary analysis. Eighty-six percent of subjects were able to perform quantitative VA testing at enrollment. The most common reasons for the diagnostic MRI included screening related to NF1 diagnosis (36.8%), ophthalmologic concerns (29.3%), and non-ophthalmologic concerns (24.8%), such as headache. To date, twenty subjects have initiated treatment with chemotherapy, twelve (9%) at the time of the initial OPG diagnosis. Median age at OPG diagnosis was 3.1 years. Age and sex distribution were similar in subjects immediately entering the observation and treatment arms (median age 3.0 versus 3.5 years, respectively). CONCLUSION Most children with NF1-OPGs are observed at time of their initial OPG diagnosis, rather than treated. Importantly, a large proportion of children are able to complete quantitative VA testing at enrollment. Once enrollment is complete, these data will help to establish evidence-based guidelines for clinical management of NF1-OPGs.

BACKGROUND Central nervous system (CNS) germinomas are radiotherapy (RT)-sensitive tumors with excellent survival. Current treatment strategies combine chemotherapy with RT to reduce the field and dose of RT. There is no standard treatment for germinomas originating in the basal ganglia/thalami (BGTG) given their rarity and poorly-defined imaging characteristics. Craniospinal (CSI), whole brain (WBI), whole ventricle (WVI), and focal RT have been previously utilized; however, the optimal strategy remains unclear. METHODS Retrospective multi-institutional analysis was conducted across 18 institutions in four countries. RESULTS For 46 cases with non-metastatic BGTG, the event-free survival (EFS) was 86.9% at both 5 and 10 years, while overall survival (OS) was 100%, and 95.7% respectively at 5 and 10 years. Median RT dose and range for the various treatment volumes were as follows: CSI (n=10): 2340 cGy (1980–3060 cGy), WBI (n=8): 2340 (1800–3000 cGy), WVI (n=14): 2340 cGy (1800–2550 cGy), focal (n=9): 3600 cGy (3060–5400 cGy). There was no statistically significant difference in the EFS based on RT modality (p=0.57), but EFS for subjects with CSI and WBI were both 100%. The three subjects who received chemotherapy alone had significantly lower EFS than those who received chemotherapy and RT (p=0.001), but were salvageable with RT. CONCLUSION In the largest study to date for BGTG, there were no significant differences in outcomes between patients who received CSI, WBI, WVI or focal RT. This group of patients should be included in future prospective clinical trials, and a more limited RT field may be considered.

INTRODUCTION Vascular endothelial growth factor receptor (VEGFR), platelet derived growth factor receptor (PDGFR), and c-KIT represent clinically and/or preclinically validated molecular targets in vestibular schwannomas. We conducted a single institution, prospective, open-label, two-stage phase II study (ClinicalTrials.gov identifier NCT02129647) to estimate the response rate to axitinib, an oral multi-receptor tyrosine kinase inhibitor targeting VEGFR, PDGFR and c-KIT, in neurofibromatosis type 2 (NF2) patients with progressive vestibular schwannomas (VS). METHODS NF2 patients older than 5 years with at least one volumetrically measurable, progressive VS were eligible. The primary endpoint was to estimate the objective volumetric response rates to axitinib. Axitinib was given continuously in 28-day cycles for up to of 12 cycles. Response was assessed every 3 months with MRI using 3-D volumetric tumor analysis and audiograms. Volumetric response and progression were defined as ≥20% decrease or increase in VS volume, respectively. RESULTS Twelve eligible patients (ages: 14–56 years) were enrolled on this study. Seven of twelve patients completed 12 cycles (range: 2 to 12 cycles). We observed two imaging and three hearing responses. Best volumetric response was -53.9% after nine months on axitinib. All patients experienced drug-related toxicities, the most common adverse events were diarrhea, hematuria and skin toxicity, not exceeding grade 2 and hypertension, not exceeding grade 3. CONCLUSIONS While axitinib has modest anti-tumor activity in NF2 patients, it is more toxic and appears to be less effective compared to bevacizumab. Based on these findings, further clinical development of axitinib for this indication does not appear warranted.

ONC201, an anti-cancer DRD2 antagonist and ClpP agonist, is in Phase II trials for adult H3 K27M-mutant diffuse midline gliomas. In adults, the recommended phase 2 dose (RP2D) of 625mg ONC201 once a week has been established as a biologically active dose that is well tolerated. Radiographic regressions with single agent ONC201 have been reported in adult recurrent H3 K27M-mutant glioma patients. This multi-arm, dose-escalation and dose-expansion trial determined the pediatric RP2D of ONC201 administered as an oral capsule (Arm A) or liquid formulation (Arm E) in post-radiation H3 K27M-mutant glioma (Arm A) or in newly diagnosed DIPG (Arm B) patients. Molecular assessments include intratumoral ONC201 concentrations (Arm C) and CSF H3 K27M DNA levels (Arm D). Enrollment as of April 30, 2020 is complete in Arm A (22) and Arm E (26) and continues in Arm B (18/24), Arm C (5/12), and Arm D (22/24). The RP2D of weekly 625mg ONC201 scaled by body weight was confirmed when administered as a capsule or a liquid formulation as a single agent or in combination with radiation without dose-limiting toxicity. The most frequent adverse events regardless of attribution to the drug were predominantly low grade: ONC201 capsule alone was headache (54.5%), nausea (36.4%), and fatigue (36.4%); ONC201 liquid formulation was vomiting (31.8%), headache (22.7%), VIth nerve disorder (22.7%); ONC201 capsules in combination with radiation (Arm B) was headache (47.1%), vomiting (52.9%), nausea (41.2%). Pharmacokinetic analysis in plasma of Arm A patients revealed T1/2: 8.4h; Tmax: 2.1h; Cmax: 2.3ug/mL; AUC0-tlast: 16.4ug/mL, with similar exposure across body weights. In conclusion, when scaled by body weight the ONC201 capsule or liquid formulation alone or in combination with radiation were associated with safety and pharmacokinetic profiles in pediatric H3 K27M-mutant diffuse midline glioma patients that are similar to the experience in adults.

BACKGROUND Bevacizumab treatment at 2.5–5 mg/kg/week is associated with hearing improvement and tumor shrinkage in about 40% of patients with neurofibromatosis 2 (NF2) and progressive vestibular schwannomas (VS). Treatment-emergent hypertension and proteinuria are common with prolonged treatment, and data supporting strategies to maintain hearing and minimize toxicity are lacking. METHODS We conducted a multicenter, phase II, open-label study of bevacizumab for subjects (≥6 years old) with NF2, hearing loss, and progressive VS. After 6 months of induction therapy (10 mg/kg every 2 weeks), subjects received low dose bevacizumab at 5 mg/kg every 3 weeks during maintenance therapy (18 months). Hearing decline was defined as a significant decrease in word recognition score below baseline. Progressive disease was defined as ≥20% increase in tumor volume from baseline. RESULTS Twenty of 22 subjects (median age=23 years) were treated with maintenance bevacizumab. The proportion of subjects free from hearing decline at 6, 12, and 18 months was 88%, 94%, and 85%, respectively; the proportion free from tumor progression at 6, 12, and 18 months from baseline was 88%, 94%, and 85%, respectively. Three subjects (15%) experienced hearing loss during maintenance and required dose escalation. Maintenance chemotherapy with bevacizumab was well tolerated: 1 subject discontinued due to perirectal abscess and 2 discontinued by choice. Grade 3 hypertension occurred in 2 subjects (10%). Adverse events of interest included hypertension (55%), proteinuria (20%), and irregular menstruation (6/13, 46%). CONCLUSIONS Maintenance chemotherapy with bevacizumab at 5 mg/kg every 3 weeks is associated with prolonged hearing and tumor stability that surpasses historical controls. A minority of subjects require dose escalation during low dose bevacizumab treatment.

We report a case of a slow-growing, diffuse, infiltrating glioma in the right brainstem of a 9-yr-old boy. The tumor was negative by immunohistochemical staining for histone H3 K27M, BRAF V600E, and IDH1 R132H mutations. Fluorescence in situ hybridization did not reveal a BRAF duplication. Genomic profiling of the tumor, by DNA methylation array and cancer whole-exome and transcriptome sequencing, was performed. This analysis showed copy-number alterations, including gains of several chromosomes. In addition, a novel fusion involving the first 17 exons of FGFR2 fused to exon 2 of VPS35 was identified. This novel fusion is predicted to result in activation of fibroblast growth factor receptor (FGFR) signaling and is potentially targetable using FGFR inhibitors. This tumor expands the spectrum of pediatric diffuse gliomas.

3619 Background: ONC201 is a first-in-class DRD2 antagonist and ClpP agonist that has demonstrated promising activity in high-grade glioma preclinical models and radiographic regressions with single agent ONC201 in recurrent H3 K27M-mutant glioma patients . The recommended phase 2 dose (RP2D) of 625mg ONC201 orally once a week has been established in adult patients as well tolerated and biologically active. ONC201 efficacy has been shown in high-grade glioma preclinical models and radiographic regressions with single agent ONC201 have been reported in adult recurrent H3 K27M-mutant glioma patients. We report results from the first Phase I pediatric clinical trial of ONC201. Methods: This open-label, multi-center trial for pediatric H3 K27M-mutant glioma or non-biopsied DIPG employed a 3+3 dose-escalation and dose-expansion design with 6 arms. Arms A and E, which have completed accrual, determined the RP2D of ONC201 using oral capsule and liquid formulations in post-radiation pediatric H3 K27M-mutant glioma patients ONC201, respectively. Arm B aims to determine the RP2D for ONC201 in combination with radiotherapy in patients with newly diagnosed DIPG. Arms C and D aim to measure intratumoral ONC201 concentrations in midline glioma patients and the impact of ONC201 on H3 K27M DNA levels in CSF, respectively. Arm F was recently opened to study ONC201 as a single agent in patients with progressive H3 K27M-mutant tumors (excluding DIPG and spinal cord tumors) following radiotherapy. After determining the RP2D, a dose-expansion cohort will evaluate the safety, radiographic response, and activity of ONC201. Results: An RP2D of weekly 625mg ONC201 scaled by body weight as a capsule or in liquid formulation was established in the primary endpoints of arms A, B and E alone or in combination with radiation, without incidence of dose-limiting toxicity (DLT). Pharmacokinetic profiles were similar to those observed in adults (T1/2: 8.4h; Tmax: 2.1h; Cmax: 2.3ug/mL; AUC0-tlast: 16.4ug/mL), with similar exposure across body weights. Conclusions: ONC201 was well tolerated without DLTs at the same adult RP2D scaled by body weight as monotherapy or in combination with radiotherapy in pediatric H3 K27M-mutant glioma patients. Further investigation of ONC201 to treat H3 K27M-mutant glioma and DIPG is warranted. Clinical trial information: NCT03416530 .

BACKGROUND: The dismal outcome in children with high-grade brainstem gliomas (BSG) accentuates the need for effective therapeutic strategies. We investigated the role of intensive, including marrow-ablative, chemotherapy regimens in the treatment of young children with newly-diagnosed high-grade BSG. METHODS: Between 1991-and-2002, 15 eligible children less than 10 years of age with a diagnosis of high-grade BSG were treated on “Head-Start” I and II protocols (HSI and HSII). Treatment included Induction with 4-5 cycles of one of three intensive chemotherapy regimens followed by Consolidation with one cycle of marrow-ablative chemotherapy (thiotepa, carboplatin and etoposide) with autologous hematopoietic cell rescue (AHCR). Irradiation was required for children over 6 years of age or for those with residual tumor at the end of Consolidation. RESULTS: We had two long-term survivors who were found retrospectively to harbor low-grade glial tumors and thus were not included in the survival analysis. Of the remaining 13 patients, the 1-year event-free (EFS) and overall (OS) survival for these children were 31% (95% CI: 9-55%) and 38% (95% CI: 14 to 63%), respectively. Median EFS and OS were 6.6 (95% CI: 2.7, 12.7) and 8.7 months (95% CI: 6.9, 20.9), respectively. Eight patients developed progressive disease during study treatment (seven during Induction and one at the end of Consolidation). Ten children received focal irradiation, five for residual tumor (three following Induction and two following Consolidation) and five due to disease progression. CONCLUSIONS: Children with high-grade BSG did not benefit from this intensive chemotherapy strategy administered prior to irradiation.

INTRODUCTION: Epidermal growth factor receptors EGFR and ErbB2 are overexpressed in schwannomas and meningiomas. Preclinical and clinical data indicate that lapatinib, an EGFR/ErbB2 inhibitor, has antitumor activity against vestibular schwannomas in neurofibromatosis type 2 (NF2) patients. Its antitumor activity against meningiomas, however, is unknown. METHODS: We conducted a retrospective review of patients with NF2 and progressive vestibular schwannomas treated on a Phase II clinical trial with lapatinib (NCT00973739). We included patients with at least one volumetrically measurable meningioma (>0.5 cm(3)) who received at least five 28-day courses of treatment. Patients received lapatinib 1,500 mg daily. Meningioma response was assessed using 3-dimensional MRI volumetrics. Progressive meningioma growth and response were defined as +20% and −20% change in tumor volume from baseline, respectively. Off-treatment was defined as any period >5 months without lapatinib. RESULTS: Eight patients (ages: 20–58 years) who met criteria had 17 evaluable meningiomas with a combined volume of 61.35 cc at baseline, 61.17cc during treatment, and 108.86 cc (+77.44% change) off-treatment, P = 0.0033. Median time on-treatment and off-treatment was 15.5 and 16.7 months, respectively. On-treatment mean and median annualized growth rates were 10.67% and 1.32%, respectively. Off-treatment mean and median annualized growth rates were 20.05% and 10.42%, respectively. The best volumetric response was −26.1% after 23 months on lapatinib. Two tumors increased >20% volumetrically on-treatment, compared to 8 tumors off-treatment. CONCLUSIONS: These data suggest that lapatinib may have growth-inhibitory effects on meningiomas in NF2 patients, and support prospective studies of lapatinib for NF2 patients with progressive meningiomas.

BACKGROUND: Plexiform neurofibromas (PNs) are histologically complex peripheral nerve sheath tumors composed of Schwann cells and fibrocytes. Pre-clinical models have demonstrated that altering the microenvironment with molecular targeting therapy may lead to the shrinkage of PN. Here we test the activity of Cabozantinib, a tyrosine kinase inhibitor of KIT, MET, VEGF, and AXL, in adolescents and adults with NF1-associated PN. METHODS: The NFCTC conducted a study (NCT02101736) evaluating Cabozantinib in subjects ≥16 years with clinically significant PN. Response was determined by MRI assessment of tumor volume. Cabozantinib was administered daily on a continuous dosing schedule for up to 2 years. Starting dose was 40 mg oral daily dose with a dose escalation to 60 mg. Success was determined as ≥ 25% of subjects achieving and maintaining ≥ 20% decrease in tumor volume. RESULTS: 19 evaluable subjects were assessed with a mean age of 23. Subjects were evaluable if they completed at least 1 cycle of therapy and had at least one follow-up tumor imaging. 4 subjects were not evaluable due to enrollment error (n=2), withdrawal during cycle 1 (n=1), ineligible due to eligibility exclusions (n=1). Eight patients (42%) met criteria for PR by 1 year. No subjects had PN progression. Common toxicities were gastrointestinal, hypothyroidism, fatigue, headaches, skin and leukopenia. Three subjects experiencing grade 3 SAEs remained on study after dose reductions. CONCLUSIONS: Cabozantinib demonstrated activity and was well tolerated in patients with clinically significant PN. This trial will be expanded to include a cohort of children

Profound hearing loss is common in patients with neurofibromatosis 2 (NF2) and vestibular schwannomas (VS). Bevacizumab treatment at 7.5 mg/kg every 3 weeks has been associated with hearing improvement and tumor shrinkage in 36% and 43% of patients, respectively. However, the optimal treatment dose and schedule are unknown. This multicenter, phase II, open-label study evaluated subjects (≥6 years old) with NF2 and progressive VS. Subjects received bevacizumab 10 mg/kg every 2 weeks during induction therapy (6 months), and 5 mg/kg every 3 weeks during maintenance therapy (18 months). Hearing response was defined as a significant increase in word recognition score above baseline. Radiographic response was defined as ≥20% decrease in tumor volume from baseline. The primary endpoint was hearing response rate in the target ear at 6 months. We enrolled 22 subjects (median age=23 years). The overall hearing and radiographic response rates were 41% (9/22) and 23% (5/22), respectively. In an unplanned post-hoc analysis, the hearing and radiographic response rates were 14% (1/7) and 0% in pediatric subjects ≤21 years, as compared with 53% (8/15) and 33% (5/15) in adult subjects. Bevacizumab was well tolerated. Adverse events included hypertension, proteinuria, arthralgias, AST/bilirubin elevation, delayed wound healing, fatigue, and irregular menstruation. 11/13 women with elevated FSH underwent evaluation for premature ovarian insufficiency. All continued treatment with bevacizumab. Bevacizumab treatment at 10 mg/kg every 2 weeks is associated with hearing and radiographic response rates comparable to previous studies using lower doses. Pediatric subjects appear to benefit less than adults during bevacizumab treatment.

Purpose This phase II trial evaluated the effect of neoadjuvant chemotherapy with or without second-look surgery before craniospinal irradiation on response rates and survival outcomes in children with newly diagnosed nongerminomatous germ cell tumors. Patients and Methods Induction chemotherapy consisted of six cycles of carboplatin/etoposide alternating with ifosfamide/etoposide. Patients demonstrating less than complete response after induction chemotherapy were encouraged to undergo second-look surgery. Patients who did not achieve complete response or partial response after chemotherapy with or without second-look surgery proceeded to high-dose chemotherapy with thiotepa and etoposide and autologous peripheral blood stem-cell rescue before craniospinal irradiation. Results The study included 102 patients treated between January 2004 and July 2008. Median age was 12 years, and 76% were male; 53.9% had pineal region masses, and 23.5% had suprasellar lesions. Sixty-nine percent of patients achieved complete response or partial response with neoadjuvant chemotherapy. At 5 years, event-free survival was 84% ± 4% (SE) and overall survival was 93% ± 3%. During the median follow-up of 5.1 years, 16 patients recurred or progressed, with seven deaths after relapse. No deaths were attributed to therapy-related toxicity. Relapse occurred at the site of primary disease in 10 patients, at a distant site in three patients, or both in one patient. In two patients, progression was detected by marker increase alone. Increased serum α-fetoprotein was a negative prognostic variable. Histologic subtype and increase of beta-human chorionic gonadotropin were not significantly correlated with worse outcomes. Conclusion Neoadjuvant chemotherapy with or without second-look surgery achieved high response rates contributing to excellent survival outcomes in children with newly diagnosed nongerminomatous germ cell tumors. This regimen should be included as a backbone for further studies.

The purpose of this study is to determine the accuracy with which a non-Gaussian measure of diffusion, mean kurtosis (MK), predicts the histologic grade of pediatric brain tumors. After institutional review board approval, 21 World Health Organization (WHO) grade I, 7 WHO grade II, and 7 WHO grade IV pathologically-proven intracranial pediatric malignancies were retrospectively reviewed for preoperative diffusional kurtosis imaging. Multiple diffusion metrics of the tumors including MK, mean diffusivity (MD) and fractional anisotropy (FA) were determined. Comparisons between groups were performed using the Mann-Whitney test (p < .05). Receiver operating characteristics analysis was done to assess accuracy of each metric in predicting histologic grade. MK was significantly higher for grade IV neoplasms (0.97, p < 0.0004) than grade I (0.62) or grade II (0.67) tumors. MD was significantly higher for grade I (1.43) compared with grade IV neoplasms (1.07, p < 0.018), however not for grade II (1.43) compared with grade IV (p < 0.08) tumors. FA did not differ significantly between grades. Area under the recei- ver operating characteristic curve was highest for MK (0.94) and lower for MD (0.89). FA performed only slightly better than chance (0.54). MK is an accurate diffusion metric for predicting histologic grade of pediatric brain tumors, consistent with conclusions from prior studies demonstrating similar results in adult populations.

SUMMARY The following is a general overview of the management of CNS germinomas. Over the last 35 years, CNS germinomas have become one of the pediatric brain tumors with the best outcomes with a greater than 85% overall survival over 5 years. This is in part due to the fact that germinomas are very responsive to chemotherapy and radiation. Some of the major challenges going forward will be to find ways to minimize the adverse effects of our treatments particularly with regard to radiation and to improve the quality of life of patients who develop neurologic, neurocognitive and/or endocrine deficiencies.

Objectives To evaluate patterns of relapse and outcome in patients newly diagnosed with CNS Mixed Malignant GCT (MMGCT) treated initially with chemotherapy alone. Methods A retrospective chart review was conducted using all 25 patients enrolled on the International CNS GCT Study III, with at least 7 years follow-up for all surviving patients. Results Thirteen patients at diagnosis had CNS MMGCT by pathology and tumor markers (n = 11), or tumor markers alone (n = 2). Twelve received chemotherapy alone, one additionally receiving focal irradiation prior to relapse. Six patients (46%) relapsed (mean of 30.5 months; range 6–59 months), two beyond and four within the primary site alone. Three patients relapsed early (6–23 months from diagnosis), two with alpha-fetoprotein elevations and one without tumor markers assessed; all three expired of progressive disease at 2–10 months following initial relapse. Three patients relapsed late (37–59 months) without AFP elevations, one with pathologically pure germinoma, two with mild beta-human chorionic gonadotropin elevations; these patients survive disease-free at 86+, 94+, and 126+ months following additional treatment. Conclusions Patients with CNS MMGCT relapsing following chemotherapy alone display two distinct patterns of recurrence and outcome; patients relapsing early possess MMGCT elements and have a dismal prognosis, while patients relapsing late do so with pure germinomatous elements and have an excellent outcome. Current cooperative group studies utilizing more localized fields of irradiation should monitor closely the patterns of relapse and outcome; late recurrences with germinomatous elements might be avoided by initial use of low-dose larger field irradiation in select patients. Pediatr Blood Cancer © 2015 Wiley Periodicals, Inc.

Identifying modifiers of glioma risk in patients with type I neurofibromatosis (NF1) could help support personalized tumor surveillance, advance understanding of gliomagenesis, and potentially identify novel therapeutic targets. Here, we report genetic polymorphisms in the human adenylate cyclase gene adenylate cyclase 8 (ADCY8) that correlate with glioma risk in NF1 in a sex-specific manner, elevating risk in females while reducing risk in males. This finding extends earlier evidence of a role for cAMP in gliomagenesis based on results in a genetically engineered mouse model (Nf1 GEM). Thus, sexually dimorphic cAMP signaling might render males and females differentially sensitive to variation in cAMP levels. Using male and female Nf1 GEM, we found significant sex differences exist in cAMP regulation and in the growth-promoting effects of cAMP suppression. Overall, our results establish a sex-specific role for cAMP regulation in human gliomagenesis, specifically identifying ADCY8 as a modifier of glioma risk in NF1. Cancer Res; 75(1); 16–21. ©2014 AACR.

Schwannomatosis is characterized by multiple non-intradermal schwannomas with patients often presenting with a painful mass in their extremities. In this syndrome malignant transformation of schwannomas is rare in spite of their large size at presentation. Non-invasive measures of assessing the biological behavior of plexiform neurofibromas in neurofibromatosis type 1 such as positron emission tomography (PET), CT scanning and MRI are well characterized but little information has been published on the use of PET imaging in schwannomatosis. We report a unique clinical presentation portraying the use of PET imaging in schwannomatosis. A 27-year-old woman presented with multiple, rapidly growing, large and painful schwannomas confirmed to be related to a constitutional mutation in the SMARCB1 complex. Whole body PET/MRI revealed numerous PET-avid tumors suggestive of malignant peripheral nerve sheath tumors. Surgery was performed on multiple tumors and none of them had histologic evidence of malignant transformation. Overall, PET imaging may not be a reliable predictor of malignant transformation in schwannomatosis, tempering enthusiasm for surgical interventions for tumors not producing significant clinical signs or symptoms.

BACKGROUND: ITP has been described in case reports and a few small series of patients with solid tumors. One possible mechanism of ITP associated with cancer is tumor- induced autoimmunity. CASE DESCRIPTION: A now 15 -year -old female with neurofibromatosis 1 (NF-1) was diagnosed at 6 years of age with an optic pathway glioma. She received treatment with carboplatin and vincristine, and had stable disease for 11 months, until she developed an allergic reaction to carboplatin. At 10 years of age, she exhibited progressive disease and received immunotherapy with three doses of an HLA-restricted peptide vaccine given over 6 weeks. At age 11, she was diagnosed with immune thrombocytopenia, which was controllable with WinRho, and her platelet count remained between 50,000–60,000. At age 14, despite stable MRI findings, she experienced a decrease in visual acuity necessitating further treatment, and Everolimus was instituted. After one year of treatment, her vision has remained stable, and she has a sustained improvement in her platelet count to above 200,000. DISCUSSION/CONCLUSION: There are a number of extenuating factors that may have possibly contributed to the occurrence of ITP, including the emergence of OPG, the allergic reaction to carboplatin, and the prior immunotherapy protocol. Our patient’s decline in visual acuity prompting treatment was closely related temporally to the development of chronic ITP, suggesting the possibility of immune cell dysregulation in both the immune cytopenia and tumor growth. Everolimus, an mTOR inhibitor, has been observed to cause regression of several types of tumors as well as alter immune function and, in a larger series of patients in China, suppress manifestations of ITP. However, this case is unusual in the quick and enduring response of the ITP to Everolimus. This case suggests the efficacy of both the anti-tumor and immunomodulatory effects in Everolimus treatment.

Background Data on ovarian function (OvF) in medulloblastoma (MB) survivors is limited, with most studies describing outcomes in survivors treated with craniospinal irradiation (CSI) doses >24 Gy ± standard chemotherapy. The objective of the current study is to report on OvF: (i) across a range of CSI doses; and (ii) following high-dose chemotherapy with autologous stem cell rescue (ASCR). Procedure Retrospective review of female MB survivors who were diagnosed in childhood and followed at Memorial Sloan Kettering Cancer Center. Patients were divided into three groups: (i) CSI ≤24 Gy +/− standard chemotherapy; (ii) CSI ≥35 Gy +/− standard chemotherapy; and (iii) high-dose chemotherapy with ASCR +/− CSI. Results Primary ovarian dysfunction (POD) occurred in 2/17 subjects in group 1, 3/9 subjects in group 2 and 5/5 subjects in group 3 (P

The prognosis of diffuse intrinsic pontine glioma (DIPG) remains poor, with no drug proven to be effective.Patients with clinically and radiologically confirmed, centrally reviewed DIPG, who had failed standard first-line therapy were eligible for this multicenter phase II trial. The anti-epidermal growth factor receptor (EGFR) antibody, nimotuzumab (150 mg/m(2)), was administered intravenously once weekly from weeks 1 to 7 and once every 2 weeks from weeks 8 to 18. Response evaluation was based on clinical and MRI assessments. Patients with partial response (PR) or stable disease (SD) were allowed to continue nimotuzumab.Forty-four patients received at least one dose of nimotuzumab (male/female, 20/24; median age, 6.0 years; range, 3.0-17.0 years). All had received prior radiotherapy. Treatment was well tolerated. Eighteen children experienced serious adverse events (SAEs). The majority of SAEs were associated with disease progression. Nineteen patients completed 8 weeks (W8) of treatment: There were 2 PRs, 6 SDs, and 11 progressions. Five patients completed 18 weeks (W18) of treatment: 1 of 2 patients with PR at W8 remained in PR at W18, and 3 of 6 children with SD at W8 maintained SD at W18. Time to progression following initiation of nimotuzumab for the 4 patients with SD or better at W18 was 119, 157, 182 and 335 days, respectively. Median survival time was 3.2 months. Two patients lived 663 and 481 days from the start of nimotuzumab.Modest activity of nimotuzumab in DIPG, which has been shown previously, was confirmed: A small subset of DIPG patients appeared to benefit from anti-EGFR antibody treatment.

Background: Cabozantinib, an oral FDA approved multi-receptor tyrosine kinase inhibitor, was tested in our preclinical mouse model of PN. After finding significant reduction of tumor number and size in cabozantinib treated versus control mice, we sought to translate these findings to a phase 2 human study. Here we report the activity of cabozantinib in adolescents and adults with NF1-associated PN. Methods: A multicenter, nonrandomized phase 2 trial (NCT02101736) of cabozantinib in subjects ≥16 years with NF1 and either progressive or clinically significant inoperable PN was performed by the NFCTC (NF-105). The primary study aim was volumetric response of the target PN determined by MRI read centrally. Cabozantinib was administered continuously for up to 24 cycles, each cycle was 28 days. The starting dose was 40 mg once daily with planned escalation to a target dose of 60 mg once daily after 2 cycles. Dose reductions for toxicity were allowed to 20 mg once daily. Partial response (PR) was defined as ≥20% reduction in tumor volume from baseline. Subjects were considered evaluable for response if they completed ≥1 cycle of therapy and had a follow-up MRI. Success was defined as ≥25% of subjects achieving and maintaining a PR after 12 cycles without significant toxicity. Investigation of the impact of cabozantinib on the PN kinome network was performed on murine samples. Results: Twenty-three subjects enrolled; 21 subjects (median age 22 years) were evaluable for toxicity (2 noted to be ineligible before receiving study drug) and 19 subjects (median age 23 years) were evaluable for response (1 subject withdrew during cycle 1 and 1 was found ineligible after starting study drug). Baseline median tumor size was 557 mL (range 57-2954 mL). Among the evaluable patients, 8 (42%) met criteria for PR by cycle 12. Median change in tumor volume was -15.2% (range +2.2% to -36.9%). No subject had PN progression on treatment; maximal tumor response was not achieved until at least 18 cycles in 6/8 responders. A significant portion of patients underwent dose reductions or discontinued cabozantinib due to low grade adverse events (AE) that impaired quality of life; however, 3 responders reduced to 20 mg maintained or improved their response at this dose. The most common AEs (any grade) in ≥10 patients included gastrointestinal toxicity, hypothyroidism, fatigue and palmar plantar erythrodysesthesia (PPE). Eleven grade 3 AEs occurred in 8 patients, mainly PPE (n=4) and hypertension (n=2); no grade 4 or 5 AEs occurred. Analysis of kinase activity in murine PN treated with cabozantinib showed significantly decreased activity of AXL, MERTK and MET, known cabozantinib targets, but also of DDR1 and DDR2. Conclusions: Cabozantinib demonstrates considerable clinical activity for PN with a radiographic response rate of 42%. Although there were few severe AEs, low grade toxicities impacted the willingness of many subjects to continue treatment. Quantitative kinome analysis revealed that inhibition of DDR1, DDR2, AXL, MERTK and MET might underpin the therapeutic responses seen in these patients. Lower doses of cabozantinib may be optimal for the NF1 population and still lead to therapeutic response. This trial is now enrolling a pediatric cohort of children aged 3 to 15 years. Supported by DOD Award W81XWH-12-1-0155 and Exelixis Citation Format: Chie-Schin Shih, Jaishri Blakeley, D. Wade Clapp, Amy E. Armstrong, Pam Wolters, Eva Dombi, Gary Cutter, Nicole J. Ullrich, Jeffrey Allen, Roger Packer, Stewart Goldman, David H. Gutmann, Scott Plotkin, Tena Rosser, Kent Robertson, Brigitte Widemann, Steven Rhodes, Steven Angus, Gary Johnson, Bruce Korf, Michael J. Fisher. Treatment of neurofibromatosis type 1 (NF1)-related plexiform neurofibromas (PN) with cabozantinib (XL184): A Neurofibromatosis Clinical Trials Consortium Phase II trial [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr CT233.

10046 Background: ONC201 is the first DRD2 antagonist for clinical oncology. The recommended phase 2 dose (RP2D) of 625mg ONC201 orally once a week has been established in adult patients. ONC201 efficacy has been shown in high-grade glioma preclinical models and radiographic regressions with single agent ONC201 have been reported in adult recurrent H3 K27M-mutant glioma patients. We report results from the first Phase I pediatric clinical trial of ONC201. Methods: This multicenter, open-label, dose-escalation and dose-expansion clinical trial (NCT03416530) determined the RP2D of ONC201 in pediatric H3 K27M-mutant glioma patients as a single agent. ONC201 was orally administered once a week and scaled by body weight. Dose escalation was performed by a 3 + 3 design beginning with one 125mg capsule less than the adult RP2D equivalent. Three patients were treated at the starting dose and 19 were treated at the adult RP2D equivalent. Results: The primary endpoint was achieved by establishing the safety of the adult RP2D scaled by body weight to pediatric patients. Twenty-two patients with a median age of 9 (range 3-18) years old who received at least prior radiation have been treated with ONC201: 15 with diffuse intrinsic pontine glioma (DIPG) (4 recurrent; 11 not recurrent) and 7 with non-DIPG H3 K27M-mutant glioma (all not recurrent). As of February 5, 2019, patients have received a median of 18 ONC201 doses (range 3-41) without instance of dose-limiting toxicity. Pharmacokinetic profiles were comparable to those observed in adults (Cmax ~2.1ug/mL; AUC ~2.3hr*ug/mL) and exposure was similar across body weights. Nine of 22 patients remain on therapy, 13 have discontinued due to progression, and 4 off-study patients are alive with a median follow up of 5.8 months. Five of the 11 (45%) DIPG patients who initiated ONC201 following radiation, but prior to recurrence, remain on therapy (median 7.4 months; range 4.4-9.6): median PFS is 4.4 months from initiation of ONC201 and 9.7 months from diagnosis; 7 of 11 (64%) patients are alive with median follow up of 11.8 months from diagnosis. Conclusions: ONC201 was well tolerated and achieved therapeutic exposure in pediatric H3 K27M-mutant glioma patients at the adult RP2D scaled by body weight. Further investigation of first-line ONC201 to treat H3 K27M-mutant glioma and/or DIPG is ongoing. Clinical trial information: NCT03416530.