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To investigate the association between assisted reproductive technology (ART) use and childhood cancer subtype.We deployed a cross-sectional survey of 1701 parents of children with cancer about their ART use, demographics, and gestational and perinatal factors. Multivariable logistic regression modeled the association between ART use, birthweight and multiple gestation status with childhood cancer, by subtype.ART use was highest among children with osteosarcoma relative to children with other cancer types, and this association was statistically significant in multivariable models (OR = 4.4; 95% CI = 1.7-11.3; p = 0.0020). ART use was also elevated among children with hepatoblastoma, but this relationship appeared to be due to the strong associations between ART use and lower birthweight in our sample. No specific ART modality appeared to drive these associations. In univariate models, multiple gestation was associated with a 2.7-fold increased odds of hepatoblastoma (OR = 2.71; 95% CI = 1.14-6.42; p = 0.02) and a 1.6-fold increased odds of neuroblastoma (OR = 1.62; 95% CI = 1.03-2.54; p = 0.03), but these associations were not retained in multivariable models.Associations between ART use and hepatoblastoma risk may be attributable to birthweight, a known hepatoblastoma risk factor. ART use may also be associated with osteosarcoma, independent of birthweight, an association not previously observed in studies limited to cancers diagnosed before adolescence. Evaluating long-term health outcomes in children conceived by ART, throughout adolescence and potentially into adulthood, appears warranted.

Background There are limited data available on incidence and survival of patients with choroid plexus tumors (CPT). This study provides the most current epidemiological analysis of choroid plexus tumors from 2004 to 2017 in the United States. Methods Data on 2013 patients with CPT were acquired from the Central Brain Tumor Registry of the United States in collaboration with the Centers for Disease Control and Prevention (CDC) and the National Cancer Institute, from 2004 to 2017. CPT cases were classified by the following pathological subtypes: choroid plexus papilloma (CPP), atypical choroid plexus papilloma (aCPP), and choroid plexus carcinoma (CPC). Frequencies and age-adjusted incidence rates (AAIR) per 100 000 and rate ratios per 100 000 (IRR) were reported for age, sex, race, and ethnicity for each pathological subtype with 95% confidence intervals (95% CI). Using CDC’s National Program of Cancer Registries survival database, survival curves and hazard ratios (HRs) evaluated overall survival from 2001 to 2016. Results CPP had the highest overall incidence (AAIR: 0.034, 95% CI: 0.033–0.036), followed by CPC (AAIR: 0.008, 95% CI: 0.008–0.009) and aCPP (AAIR: 0.005, 95% CI: 0.005–0.006). Incidence was highest among children less than one year old among all subtypes (CPP AAIR: 0.278; aCPP AAIR: 0.140; CPC AAIR: 0.195), reducing as patients aged. Overall survival was worse among patients with CPC, being five times more likely to die compared to patients with CPP (HR: 5.23, 95% CI: 4.05–7.54, P Conclusions This analysis is the most current and comprehensive study in the US on the incidence and survival for CPT. Population based statistics provide critical information in understanding disease characteristics, which impact patient care and prognosis.

Information about methods and data that further support the claims made in this article. This includes, but is not limited to TEM8 distribution in normal tissues, CAR T cell normalization, additional control groups and CAR toxicity studies.

L2 2G and L2 3G CAR T cell normalization and functional testing.

Background Pineoblastoma (PB) is a rare malignant brain tumor originating in the pineal gland. Here, we provide a comprehensive epidemiological analysis of PB in the United States from 2000 to 2017. Methods Data on 1133 patients with PB were acquired from the Central Brain Tumor Registry of the United States, in collaboration with the Centers for Disease Control and Prevention and the National Cancer Institute, from 2000 to 2017. Age-adjusted incidence rates (AAIRs) per 100 000 and incidence rate ratios (IRRs) were reported for age, sex, race, and ethnicity. Using the National Program of Cancer Registries survival database, median survival and hazard ratios (HRs) were evaluated for overall survival from 2001 to 2016. Results Incidence was highest in ages 0–4 years (AAIR: 0.049, 95% CI: 0.042–0.056), decreasing as age increased. Incidence was higher among patients who are Black compared to patients who are White (IRR: 1.71, 95% CI: 1.48–1.98, P < .001), and was impacted by age at diagnosis, with Black-to-White incidence highest in children ages 5–9 years (IRR: 3.43, 95% CI: 2.36–4.94, P < .001). Overall survival was lower for males (HR: 1.39, 95% CI: 1.07–1.79, P = .013). All age groups, excluding those over 40, had improved survival compared to ages 0–4 years. Those who received surgical intervention had better survival compared to those who did not receive surgical treatment. Conclusion PB incidence is highest among children and patients who are Black, and there may be a potential interaction between these factors. Survival is worse among males, young children, and elderly adults, and those who received no surgery. Comprehensive, population-based statistics provide critical information on PB characteristics that could be useful in impacting patient care and prognosis.

BackgroundAntitumor mechanisms of CD4+T cells remain crudely defined, and means to effectively harness CD4+T-cell help for cancer immunotherapy are lacking. Pre-existing memory CD4+T cells hold potential to be leveraged for this purpose. Moreover, the role of pre-existing immunity in virotherapy, particularly recombinant poliovirus immunotherapy where childhood polio vaccine specific immunity is ubiquitous, remains unclear. Here we tested the hypothesis that childhood vaccine-specific memory T cells mediate antitumor immunotherapy and contribute to the antitumor efficacy of polio virotherapy.MethodsThe impact of polio immunization on polio virotherapy, and the antitumor effects of polio and tetanus recall were tested in syngeneic murine melanoma and breast cancer models. CD8+T-cell and B-cell knockout, CD4+T-cell depletion, CD4+T-cell adoptive transfer, CD40L blockade, assessments of antitumor T-cell immunity, and eosinophil depletion defined antitumor mechanisms of recall antigens. Pan-cancer transcriptome data sets and polio virotherapy clinical trial correlates were used to assess the relevance of these findings in humans.ResultsPrior vaccination against poliovirus substantially bolstered the antitumor efficacy of polio virotherapy in mice, and intratumor recall of poliovirus or tetanus immunity delayed tumor growth. Intratumor recall antigens augmented antitumor T-cell function, caused marked tumor infiltration of type 2 innate lymphoid cells and eosinophils, and decreased proportions of regulatory T cells (Tregs). Antitumor effects of recall antigens were mediated by CD4+T cells, limited by B cells, independent of CD40L, and dependent on eosinophils and CD8+T cells. An inverse relationship between eosinophil and Treg signatures was observed across The Cancer Genome Atlas (TCGA) cancer types, and eosinophil depletion prevented Treg reductions after polio recall. Pretreatment polio neutralizing antibody titers were higher in patients living longer, and eosinophil levels increased in the majority of patients, after polio virotherapy.ConclusionPre-existing anti-polio immunity contributes to the antitumor efficacy of polio virotherapy. This work defines cancer immunotherapy potential of childhood vaccines, reveals their utility to engage CD4+T-cell help for antitumor CD8+T cells, and implicates eosinophils as antitumor effectors of CD4+T cells.

BACKGROUND Outcomes of recurrent pediatric high grade glioma (pHHG) are poor with a median overall survival (OS) of < 6 months. Viral immunotherapy such as the polio:rhinovirus chimera, PVSRIPO, is a novel treatment approach for recurrent pHHG. PVSRIPO is genetically engineered to prevent neurovirulence. In adults with recurrent glioblastoma treated with PVSRIPO, 21% survived > 36 months. The poliovirus receptor, CD155, is ubiquitously expressed in malignant pediatric brain tumors including pHHG. METHODS The primary objective of this Phase 1b clinical trial was to evaluate the safety and feasibility of PVSRIPO for recurrent pHGG. PVSRIPO was given at a single dose, 5x107 50% tissue-culture infectious dose (TCID50) administered by convection enhanced delivery (CED) to children with biopsy-confirmed recurrent pHHG between ≥ 1 and ≤ 5.5 in diameter. 3 mL of PVSRIPO was delivered at 0.5 mL/hr via a single catheter. RESULTS Eight patients were treated with PVSRIPO including 5 males and 3 females with a median age of 16.5 (range 9-19). Six patients had recurrent glioblastoma, 2 had recurrent anaplastic astrocytoma. The median number of previous recurrences prior to enrollment was 3.5 (range 1-5). Four patients received bevacizumab on-study for treatment-related peritumoral inflammation/edema. Six of 8 patients experienced 26 treatment related adverse events (AEs) possibly, probably, or definitely related to protocol treatment. There were no Grade 4 or 5 AEs. There were 3 Grade 3 AEs: 2 headaches and 1 seizure. There were no AEs related to biopsy or CED catheter insertion/removal. Median OS was 4.13 months (range 1.23-NA). One patient is currently alive at > 21 months. Monocyte and T cell inflammatory phenotypes and total CD4+ T cells were increased in peripheral blood after treatment. CONCLUSIONS CED of PVSPRIO is both safe and feasible for the treatment of recurrent pHHG. Histologic correlative results will also be presented.

Glioblastoma (GBM) is the most aggressive primary brain cancer with a median survival of less than 16 months. This dire prognosis signifies the urgent need for improved treatment options, such as immunotherapy. Chimeric antigen receptor (CAR) T cells have helped revolutionize immunotherapy, achieving considerable success in eliminating hematological cancers but generally failing to control solid tumors. One major hindrance to CAR T cell success in solid tumors is tumor heterogeneity. Tumor-associated or tumor-specific antigens (TAA or TSA, respectively) are rarely expressed by all malignant cells within a tumor. As a specific example in GBM, the most prevalent TSA, EGFRvIII, is present in just 30% of tumors, and then on only 30-50% of cells. Our pre-clinical and clinical experiences with CAR T cells reveal that tumors possessing as few as 5-10% EGFRvIII-negative cells will easily escape EGFRvIII-targeted CARs. Tumor cells that lack EGFRvIII expression often overexpress the wildtype isoform of EGFR (EGFRwt). Notably, EGFR is absent on normal brain. Therefore, a superior approach would be to simultaneously target EGFRvIII and EGFRwt, an approach that would bypass EGFR heterogeneity in EGFRwt/EGFRvIII-expressing tumors. Here, we generated a third generation CAR using the D2C7 single-chain variable fragment (scFv) targeting moiety that recognizes an epitope present in EGFRwt and EGFRvIII. Initial in vitro characterization of D2C7 CAR validated the specificity and function of D2C7 CAR, as it potently killed murine cell lines engineered to express either EGFRwt or EGFRvIII, but not a cell line expressing neither. Concomitant IFN-γ release supported these conclusions. Additionally, D2C7 CAR killed the human-derived GBM cell line U87 and vIII-transfected U87, U87vIII. Importantly, intracranially-administered D2C7 CAR significantly prolonged survival of mice bearing orthotopic U87vIII or U87/U87vIII heterogeneous tumors compared to mock-treated controls. Altogether, these data provide evidence that D2C7 CAR T cells represent a viable therapeutic option for EGFRwt/EGFRvIII heterogeneous tumors.

BACKGROUND D2C7-IT, a novel immunotoxin-based cytotoxic therapy, targets epidermal growth factor receptor (EGFR) and mutant EGFR variant III. In preclinical studies, D2C7-IT kills tumor cells and prolongs survival, but is unable to generate cures in all animals. We hypothesized that immunosuppression in glioblastoma limits D2C7-IT efficacy. Eliminating glioblastoma immunosuppression via CD40 co-stimulation is anticipated to enhance D2C7-IT-induced antitumor responses. In murine glioma models, CED of D2C7-IT+αCD40 generated cures and long-term tumor-specific adaptive immunity. Hence, we are conducting a phase 1 trial of D2C7-IT+2141-V11 (αhuman-CD40) administered via CED in rMG patients. METHODS Eligibility includes adult patients with solitary supratentorial rMG (WHO grade 3/4); ≥ 4 weeks after chemotherapy, bevacizumab, or study drug; adequate organ function; and KPS ≥ 70%. Cohorts of 3 patients are treated with increasing doses of 2141-V11 to determine the maximum tolerated dose when administered sequentially following D2C7-IT (166,075 ng) via CED at 0.5 mL/hr. Five dose levels (DLs) are evaluated (2141-V11 at: #1: 0.70 mg; #2: 2.0 mg; #2**: 3.0 mg #2*: 4.0 mg; #3: 7.0 mg). RESULTS As of May 29, 2022, 13 patients were treated (3 patients on DL1, DL2, and DL2**; 2 patients on DL3 and DL2*). No dose-limiting toxicities were observed; however, lower DLs were added due to higher frequency of adverse events (AEs) expected with D2C7-IT+2141-V11 with DL3 and DL2* (fever, neurologic symptoms). All patients remain alive 0.7-10.6 months after therapy. Grade ≥ 2 AEs due to D2C7-IT+2141-V11 include: headache (grade 3, n = 1; grade 2, n = 4); pyramidal tract disorder (grade 3, n = 1; grade 2, n = 2); paresthesia (grade 3, n = 1); dysphasia (grade 3, n = 1); seizures (grade 2; n = 2); fever (grade 2; n = 2); and one each of grade 2 depressed level of consciousness, fatigue, and concentration impairment. Enrollment is ongoing. CONCLUSIONS Intratumoral administration of D2C7-IT+2141-V11 via CED is safe, encouraging efficacy results are observed.

OBJECTIVE To investigate the association between maternal prenatal substance use/abuse and diagnosis of childhood cancer subtypes, including childhood brain tumors. To minimize recall bias, we employed a case-only study design in which all respondents had a child diagnosed with cancer. STUDY DESIGN: We deployed a cross-sectional, case-only survey of parents of children diagnosed with cancer regarding prenatal smoking, drinking, and illicit drug use behaviors (scored on 1-7 Likert scale), demographic, gestational, and perinatal factors. Multivariable logistic regression assessed associations of gestational smoking, alcohol, and illicit drug use with childhood cancer subtypes, adjusting for child sex, race/ethnicity, birthweight, and household income. RESULTS 3145 families completed the survey, including 232 with astrocytoma (grades I-IV, including DIPG) and 210 with an embryonal CNS tumor (medulloblastoma, AT/RT, PNET). A minority reported ever smoking tobacco products during pregnancy (Likert score ≥ 2; 14%), ever consuming illicit drugs during pregnancy (Likert score ≥ 2; 4%), or drinking more than a moderate amount of alcohol during pregnancy (Likert score ≥ 5; 2%). Prenatal smoking was associated with lower odds of rhabdomyosarcoma (OR=0.48, P=0.023) and moderately elevated odds of non-Hodgkin lymphoma (OR = 1.52, P=0.098) and AML (OR = 1.52, P = 0.083). Moderate to heavy alcohol consumption was unassociated with cancer subtypes. Prenatal illicit drug use was associated with increased odds of retinoblastoma (OR = 5.03, 95% CI = 1.73-14.7, P = 0.003) and CNS embryonal tumors (OR = 2.56, 95% CI = 1.32-4.99, P = 0.006), with similar effects across subgroups of medulloblastoma, AT/RT, and supratentorial PNETs. CONCLUSIONS Associations between self-reported use of alcohol, tobacco, and illicit drugs during pregnancy and risk of childhood cancer is often biased by differential misreporting among parents of affected children. Consistent with prior reports, we observe elevated odds of hematologic malignancies in association with gestational tobacco smoke exposure and novel association between maternal illicit drug use during pregnancy and elevated odds of retinoblastoma and CNS embryonal tumors.

BACKGROUND RAF alterations are oncogenic drivers found in most pediatric low-grade gliomas (LGGs). Tovorafenib is an investigational, oral, selective, CNS-penetrant, small molecule, type II pan‑RAF inhibitor. METHODS FIREFLY-1 (NCT04775485) is a multicenter phase 2 study evaluating the safety and efficacy of tovorafenib monotherapy. Registrational arm 1 enrolled patients with recurrent/progressive LGG harboring an activating BRAF alteration. Patients aged 6 months–25 years who progressed following ≥ 1 prior line of systemic therapy were eligible. Tovorafenib 420 mg/m2 (≤ 600 mg) was administered weekly (tablet or liquid suspension formulation) until progression or for ≥ 26, 28-day cycles. The primary endpoint (arm 1) was overall response rate, as defined by RANO criteria, per independent review. RESULTS As of April 14, 2022, 25 patients were enrolled to arm 1 and had ≥ 6 months of follow-up. Median age at enrollment was 8 years (range 3–18). Most patients had astrocytomas (92%), 48% with optic pathway involvement. Patients were heavily pretreated (56% with ≥ 3 prior lines of therapy), and 72% previously received MAPK pathway-targeted agents. Tumors harbored BRAF fusions (84%) or BRAF V600E mutations (16%). Per independent assessment, partial responses (1 unconfirmed) were seen in 14 (64%) of 22 evaluable patients, with 6 additional patients having stable disease, and a clinical benefit rate of 91%. Responses were achieved in tumors with BRAF fusions and V600E mutations. Most treatment-emergent adverse events (AEs) were grade 1 or 2 (96%). The most common grade ≥ 3 AEs were anemia (12%), vomiting, increased blood creatinine phosphokinase and maculopapular rash (8% each). Seven patients (28%) required dose modification for treatment-related AEs; no patients discontinued tovorafenib due to AEs. Updated results, including efficacy per RAPNO assessments will be presented. CONCLUSIONS Tovorafenib was generally well tolerated and showed encouraging evidence of antitumor activity in children with pretreated BRAF-altered LGG.

ObjectivesUse of assisted reproductive technology (ART) may alter the typical course of fetal development. We sought to investigate the association between ART use and childhood cancer subtype.Study designWe surveyed 1701 parents of children with cancer about ART use, demographics, and gestational and perinatal factors. Multivariable logistic regression modeled the association between ART use and childhood cancer subtypes, birthweight and multiple gestation status.ResultsAmong childhood cancer patients, ART use was highest among children with osteosarcoma (OR=2.81; 95% CI=1.2-6.4; P=0.01). ART use was also elevated among children with hepatoblastoma, and this relationship appeared mediated by low birthweight. No specific type of ART appeared to drive these associations. Low birthweight was itself strongly associated with increased hepatoblastoma risk, even after adjustment for ART use, multiple gestation status, sex, and parental income (Pinteraction=0.02).ConclusionsAssociations between ART use and hepatoblastoma risk may be mediated by birthweight, a strong hepatoblastoma risk factor that was replicated in our study. ART use may also be associated with osteosarcoma independent of birthweight, an association not previously observed in studies limited to cancers diagnosed before adolescence. Evaluating long-term health outcomes in children conceived by ART, throughout adolescence and potentially into adulthood, appears warranted.

Glioblastoma (GBM) patients can use tumor-treating fields (TTFs) with adjuvant temozolomide (TMZ) to treat their disease. TTFs involve wearing transfixed transducers to the shaved scalp, and the transducers are wired to a battery pack that is either fixed or carried (weighing 2.7 pounds). EF-14 clinical trial did evaluate health-related quality of life with standardized patient-report outcome measures but did not measure exercise behavior. We sought to evaluate the exercise behavior of GBM patients using TTFs. We consented GBM patients who intended to use TTFs with adjuvant TMZ after completion of chemoradiation. After informed consent and before starting TTFs, patients completed a self-administered questionnaire, Godin Leisure-Time Exercise Questionnaire, to assess exercise behavior/physical function. To calculate our primary outcome of total exercise behavior, the frequency of exercise sessions per week within each intensity category was multiplied by the average reported duration, weighted by an estimate of the MET, summed across all intensities, and expressed as average MET-hr/wk. Prior work has defined that physical function can be compared as < 9 MET-h/wk vs. ≥ 9 MET-h/wk. We evaluated at baseline and up to 24-week exercise behavior in patients with TTFs vs. historical controls not using TTFs. We enrolled 19 total GBM patients, with 14 proceeding to use TTFs. Of the 14 patients on TTFs, seven patients (50%) completed ≥ 9 MET-h/wk of exercise, and this level was maintained 8, 16, and 24 weeks after starting TTFs. Six months after the completion of chemoradiation, mean MET-h/wk was decreased in the TTFs group (n=6) (10.71 sd=7.06) vs. historical controls (n=38) (27.35 sd=46.94). TTFs did not interfere with exercise behavior in our GBM cohort, but when compared to GBM patients not utilizing TTFs, there could be a long-term impact on exercise behavior. More research is needed to evaluate exercise behavior in GBM patients using TTFs.

BACKGROUND Recurrent glioblastoma (rGBM) is rapidly fatal with current therapies. PVSRIPO is an intratumoral immunotherapy targeting CD155 on antigen-presenting and malignant cells of solid tumors. Preclinically, PVSRIPO treatment leads to systemic, tumor antigen-specific, polyfunctional T-cell–mediated anti-tumor response, predominately driven by type I/III interferons. This inflammatory signature generates anti-tumor immunity and upregulates the programmed death (PD)-1 immune checkpoint in the tumor microenvironment. Preclinical models (including GBM) have shown that PVSRIPO+anti-PD-1/L1 therapy was more efficacious than either agent alone, warranting further investigation. METHODS Adults with histologically confirmed rGBM (1-2 prior progressions), Karnofsky performance status (KPS) ≥70, and an active, supratentorial, contrast-enhancing lesion (1-5.5 cm), received PVSRIPO (5x107 TCID50) intratumorally via convection-enhanced delivery (Day 1), followed by 200 mg pembrolizumab IV at week 2, given every 3 weeks for up to 24 months, to evaluate the safety/efficacy of the combination. A safety lead-in period (n=3-6) with a minimum 21–28-day delay before treatment of subsequent patients was planned, with a data safety monitoring board (DSMB) evaluating safety/tolerability prior to expansion (up to N=30). RESULTS The first 3 patients enrolled (ages 55-60, KPS 90-100) all received PVSRIPO followed by pembrolizumab (1-5 cycles), as planned. At cutoff (26-106 days of follow-up), there were no dose-limiting toxicities, treatment-emergent (TE) serious adverse events (SAE), or TEAEs necessitating a delay in initial/subsequent pembrolizumab treatments. All patients experienced a related TEAE, all grade 1 or 2 in severity. One patient experienced an AE of special interest (peritumoral edema, resulting in headache and hemiparesis), successfully managed with low-dose bevacizumab and corticosteroids. The DSMB unanimously recommended the study proceed without modification. CONCLUSIONS Intratumoral PVSRIPO+pembrolizumab was reasonably well tolerated, warranting continued investigation of the safety and efficacy of this combination in patients with rGBM.

INTRODUCTION While primary GBM is largely heterogeneous and devoid of homogeneously expressed neoantigens, mutant IDH1 (R132H) is a uniformly expressed hallmark in >70% of low grade gliomas. As such, IDH1 mutations represent a potentially valuable vaccination target. METHODS Here, we report an update on the immunogenicity results of the mutant IDH1 peptide vaccine alone and in combination with temozolomide (TMZ). In the phase I RESIST clinical trial (NCT02193347), patients with recurrent and resectable IDH1 R132H mutant grade 2 glioma received peptide vaccinations composed of 500 µg of mutant IDH1 peptide and 150 µg of GM-CSF mixed 1:1 with Montanide adjuvant prior to surgical resection. Vaccines 1, 2, and 3 were given 15 (+/-) 3 days apart. 7-12 days after vaccine 3, patients underwent standard of care tumor (SOC) resection. After resection, patients with grade 2 gliomas were given up to 15 doses of peptide vaccine in combination with TMZ regimens while patients with transformed grade 3 gliomas were given up to 15 doses of peptide vaccine in combination with SOC radiation therapy + TMZ regimens. T cell responses against the mutant peptide were measured after vaccine 3 using IFN-γ ELISPOT and intracellular flow cytometry for IL-2, TNFα,and IFNγ. RESULTS 3/20 patients were taken off the study before completion of study related activities. 1/20 patients progressed before completion of all vaccines. Out of 134 total doses of vaccine delivered, only one dose generated a grade 2 or higher injection site reaction according to the CTCAE guidelines. Vaccination with the mutant peptide led to an overall increase in IFN-γ+ spot-forming splenocytes specific to the mutant peptide (p=0.0408). CONCLUSION Administering the mutant IDH1 peptide vaccine in patients with recurrent IDH-mutant gliomas was able to induce anti-IDH1 R132H immune responses in this initial phase I study.

Brain tumors are the leading cause of cancer death in children and a significant cause of morbidity and mortality in adults. Conventional treatments are suboptimal, thus signifying the need for novel therapeutic strategies, such as immunotherapy. Chimeric antigen receptor (CAR) T cells represent a revolutionary class of immunotherapy, achieving considerable success in eliminating hematological cancers but generally failing to control solid tumors in part due to the lack of a suitably-expressed target antigen. Epidermal growth factor receptor (EGFR) is the most ubiquitous and homogeneous antigen on glial brain tumors, and EGFR-directed therapies have been hotly pursued. Moreover, the mutant EGFR variant, EGFRvIII, is present on a subset of pediatric and adult high grade gliomas, representing a targetable, tumor-specific antigen. Unfortunately, CAR T cells targeting EGFRvIII fail to treat tumors possessing as few as 5–10% EGFRvIII-negative cells due to antigen escape. Thus, a CAR T cell that can target both EGFR and EGFRvIII is expected to be superior to a CAR that targets EGFRvIII alone. In this study, we developed a novel third generation CAR T cell consisting of the D2C7scfv targeting moiety that binds a shared epitope between EGFR and EGFRvIII. This D2C7 CAR was able to specifically and potently kill tumor cells expressing wildtype EGFR or EGFRvIII. Importantly, D2C7 CAR significantly prolonged survival of mice bearing EGFR or EGFRvIII-expressing gliomas of both adult (U87) and pediatric (DAOY) origin. Toxicity experiments involving EGFR-expressing human skin grafts provided evidence that D2C7 CAR is safe and effective when administered intracranially to mice bearing intracranial tumors.

Circumscribed low-grade gliomas comprise roughly one-third of pediatric CNS tumors. Most of these tumors are caused by activating mutations in the mitogen-activated protein kinase (MAPK) pathway. Drugs targeting the MAPK pathway are effective in other cancers and are being utilized in low-grade gliomas. We describe treatment outcomes and toxicities in a series of thirteen low-grade glioma patients treated with trametinib. We performed a retrospective chart review to evaluate response on T2/FLAIR MRI images per updated RANO criteria, visual outcomes, tolerability, and durability of response in progressive low-grade glioma patients treated with trametinib. Thirteen patients age 22 months to 34 years were included. Best radiographic response on therapy included 2/13 partial response, 3/13 minimal response, 5/13 stable disease, and 3/13 progressive disease. Diagnoses included pilocytic astrocytoma (n=6), desmoplastic infantile ganglioglioma (DIG; n=1), and low-grade glial neoplasms (n=2). Molecular drivers included BRAF:KIAA1549 fusion (n=3), V600E mutation (n=1), and somatic NF1 mutation (n=1). Three patients had germline NF1. In patients with partial or minimal response, best response was seen after longer durations of therapy; 4 of 5 best responses occurred after at least 12 months on therapy. Five patients completed prescribed therapy. Three patients remain stable off therapy at 6, 12, and 21 months; two patients recurred at 1 and 10 months off therapy. Skin manifestations were the predominant form of toxicity. This was more severe in older males, and symptoms improved with intermittent dosing. All patients with optic pathway tumors showed at least stable vision throughout treatment, with some patients having dramatic improvement. Trametinib is effective and well-tolerated in patients with low-grade glioma. Dermatologic toxicity can be mitigated by intermittent dosing. Best responses tended to occur later in therapy, sometimes after relatively stable MRIs. Patients with optic pathway lesions showed stable to improved vision even in the absence of significant radiographic response.

Medulloblastoma is a heterogeneous disease with at least four distinct molecular subgroups: wingless (WNT), sonic hedgehog (SHH), Group 3, and Group 4. Recently there has been considerable progress defining the molecular drivers and prognostic factors of each subgroup. However, this information has only rarely been used to stratify risk or impact treatment. The purpose of this work is to provide an update on current clinical trials that provide molecularly stratified treatment paradigms. A search was conducted on ClinicalTrials.gov using the following search terms: "medulloblastoma and subgroup", "medulloblastoma and SHH", "medulloblastoma and WNT", and "medulloblastoma and Non-WNT/Non-SHH". This search resulted in nine distinct clinical trials, five for newly diagnosed medulloblastoma and four for recurrent medulloblastoma. Four trials for newly diagnosed medulloblastoma had a component of craniospinal irradiation reduction for patients with WNT medulloblastoma. Molecularly stratified trials for recurrent medulloblastoma largely focus on SHH. As these trials are ongoing, there are limited data available. A trial in which newly-diagnosed WNT patients received modest chemotherapy without radiation has been closed to accrual due to several early failures. Phase II trials evaluating vismodegib for SHH medulloblastoma in children and adults have been disappointing. In conclusion, although there is an expanding array of clinical trials which incorporate molecular data in prescribing treatment for newly-diagnosed and recurrent medulloblastoma, treatments for these diseases are fairly uniform, with craniospinal radiation dose being the main variable. As the drivers of the distinct subgroups and their associated prognoses are better elucidated, future clinical trials and novel targeted agents are needed to improve outcomes and reduce toxicity where feasible.

Central neurocytoma is a rare neuronal tumor that typically occurs in young adults. Infrequently, these tumors exhibit advanced neuronal maturation and glial differentiation, giving rise to a histologically diverse tumor, in contrast to a typical central neurocytoma. We present a novel case of intraventricular central neurocytoma with prominent gangliogliomatous differentiation that developed atypical features upon recurrence after 10 years of follow up in a 10-year-old boy. Our case provides insight into the divergent differentiation capability of a neurocytic tumor and illustrates the diverse histological features of this rare entity.

BACKGROUND Recurrent glioblastoma (rGBM) is rapidly fatal (median overall survival [mOS] of ~9 months; OS at 12 months [OS12] < 35%) with approved therapies (lomustine±bevacizumab). PVSRIPO is an intratumoral immunotherapy targeting CD155 on antigen-presenting and malignant cells of solid tumors. Preclinically, PVSRIPO delivers a systemic, tumor antigen-specific, polyfunctional T-cell mediated anti-tumor response. Interim, single-center, phase (Ph) 1 results showed greater long-term survival with PVSRIPO vs. criteria-matched external control rGBM patients (Desjardins 2018). Updates to Ph1 safety (at the Ph2 dose) and efficacy and interim multicenter (Ph2) results are presented. METHODS Adults with histologically-confirmed rGBM, Karnofsky performance status ≥ 70, and an active, supratentorial, contrast-enhancing lesion (1-5.5cm) received PVSRIPO (5x107 TCID50) intratumorally via convection-enhanced delivery on Day 1, with a planned follow-up of 24 months. Safety (treatment-emergent adverse events [TEAEs]), efficacy (reported as OS12, OS24, mOS), and blood/tissue were assessed. RESULTS 149 patients (>90% with 1-2 prior progressions, including failure of SOC and patients with prior bevacizumab failure) received the Ph2 dose of PVSRIPO (n=30 received other doses in Ph1 with safety summarized previously). Follow-up durations for surviving patients were 51-74 months (Ph1) and 10-44 months (Ph2). No dose-limiting toxicities occurred; up to 97% of patients experienced mostly grade 1-2 related TEAEs; ≤ 23% patients experienced grade ≥ 3 related events. Neurologic symptoms related to peritumoral edema were most common ( > 90% patients) and were effectively managed with low-dose bevacizumab/corticosteroids. Survival estimates were: OS12: 54%, 50%; OS24: 18%, 17%; mOS: 12.3 (95% CI 10,15.3), 12 (10.6,13.7) months, for the Ph1 and Ph2 trials, respectively. Baseline correlates of longer survival included smaller lesions and methylated MGMT-promoter status. CONCLUSIONS The multicenter/Ph2 study replicated the single-center/Ph1 results. Relative to published data with approved therapies, PVSRIPO was associated with greater long-term survival and mOS in patients with rGBM and was generally well-tolerated.

INTRODUCTION Vaccination with dendritic cells (DCs) fares poorly in primary and recurrent glioblastoma (GBM). Moreover, GBM vaccine trials are often underpowered due to limited sample size. METHODS To address these limitations, we conducted three sequential clinical trials utilizing Cytomegalovirus (CMV)-specific DC vaccines in patients with primary GBM. Autologous DCs were generated and electroporated with mRNA encoding for the CMV protein pp65. Serial vaccination was given throughout adjuvant temozolomide cycles, and 111Indium radiolabeling was implemented to assess migration efficiency of DC vaccines. Patients were followed for median overall survival (mOS) and OS. RESULTS Our initial study was the phase II ATTAC study (NCT00639639; total n=12) with 6 patients randomized to vaccine site preconditioning with tetanus-diphtheria (Td) toxoid. This led to an expanded cohort trial (ATTAC-GM; NCT00639639) of 11 patients receiving CMV DC vaccines containing granulocyte-macrophage colony-stimulating factor (GM-CSF). Follow-up data from ATTAC and ATTAC-GM revealed 5-year OS rates of 33.3% (mOS 38.3 months; CI95 17.5-undefined) and 36.4% (mOS 37.7 months; CI95 18.2-109.1), respectively. ATTAC additionally revealed a significant increase in DC migration to draining lymph nodes following Td preconditioning (P=0.049). Increased DC migration was associated with OS (Cox proportional hazards model, HR=0.820, P=0.023). Td-mediated increased migration has been recapitulated in our larger confirmatory trial ELEVATE (NCT02366728) of 43 patients randomized to preconditioning (Wilcoxon rank sum, Td n=24, unpulsed DC n=19; 24h, P=0.031 and 48h, P=0.0195). In ELEVATE, median follow-up of 42.2 months revealed significantly longer OS in patients randomized to Td (P=0.026). The 3-year OS for Td-treated patients in ELEVATE was 34% (CI95 19-63%) compared to 6% given unpulsed DCs (CI95 1-42%). CONCLUSION We report reproducibility of our findings across three sequential clinical trials using CMV pp65 DCs. Despite their small numbers, these successive trials demonstrate consistent survival outcomes, thus supporting the efficacy of CMV DC vaccine therapy in GBM.

Isocitrate dehydrogenase 1 (IDH1) is commonly mutated in grade II-III gliomas, and the mutant enzyme leads to the production of the oncometabolite 2-hydroxyglutarate (2-HG). 2-HG is responsible for the gliomagenesis associated with these tumors and the promotion of seizures via glutamate receptors. Ivosidenib, a small molecule oral mIDH1 inhibitor, has shown promise in clinical trials to treat IDH1 mutant gliomas, and providers can utilize this agent in IDH1 mutant glioma patients. We evaluated our IDH1 mutant glioma patients treated off-label with ivosidenib and described the radiographic response and seizure control in this cohort when ivosidenib was initiated between October 2020 to February 2021. Radiographic response was determined using RANO criteria, and seizure control was determined by comparing seizures per month before and after initiation of ivosidenib. All patients represented received single-agent ivosidenib dosed at 500 mg orally once a day. One patient required a dose reduction to 250 mg orally once a day because of drug-induced diarrhea. In our cohort of six patients, patient age range was 31 to 74 years with four female patients and two male patients. Diagnoses represented were astrocytoma, IDH1 mutant (n=3) oligodendroglioma (WHO), IDH1 mutant, 1p19q co-deleted (n=2), and anaplastic astrocytoma IDH1 mutant (n=1). Three patients experienced a reduction of seizure frequency, two patients did not have seizures before or after therapy, and one patient remained with the same level of seizures (1 seizure/month). Radiographic responses recorded included three patients with stable disease, two patients with minor responses, and one patient with a partial response. Treatment with ivosidenib is ongoing for this cohort of mIDH1 glioma patients. Updated information on prolonged disease control and seizure control in this cohort of IDH1 mutant glioma patients will be presented. Therapeutics, such as ivosidenib, can lead to improved seizure control and radiographic outcomes in IDH1 mutant glioma patients.

INTRODUCTION There is increasing recognition that palliative care (PC) can benefit patients with advanced cancers. However, early referral to PC is not yet a reality for patients diagnosed with a primary brain tumor. We hypothesize that lack of knowledge and/or misperceptions regarding PC by patients, caregivers, or their providers remain barriers. METHODS This is an IRB-exempt, one-time QR-accessible REDcap questionnaire administered to patients, caregivers, and providers at the Preston Robert Tisch Brain Tumor Center between September 2020 and May 2021. We administered 9 questions regarding knowledge and beliefs about PC from the Health Information National Trends Survey 5, Cycle 2: results of this nationally representative U.S. sample are publicly available and used for comparison. RESULTS We had 141 survey respondents: 25 providers, 59 patients, and 57 caregivers. The median patient and caregiver ages were 49 (21-74) and 50 years (24-73), respectively. Caregivers were more likely female (55.2 %) and identified as a spouse or domestic partner (58.2%). Providers, were equally distributed by years of experience. Compared to patients and caregivers, providers reported more baseline knowledge of PC (p< 0.0001, p< 0.0001) and better understood the role of PC in pain/symptom management (p=0.0038, p=0.0087) and social/emotional support (p=0.0044, p=0.0279). Interestingly, most providers (76.0%) disagreed with the statement “the goal of palliative care is to give patients more time at the end of life.” Compared to a general U.S. sample (n=1,162) our patients (n=39) were better informed in only 2 of 9 questions. Whereas, caregivers (n=48) were better informed in 6 of 9 questions. CONCLUSION Neuro-oncology providers were knowledgeable, but a minor gap in understanding the goal of PC was identified. Caregivers were overall more knowledgeable than patients. However, Neuro-oncology patients, had similar knowledge and beliefs compared to a nationally representative sample. PC interventions should prioritize filling knowledge gaps for Neuro-oncology patients.

INTRODUCTION The use of telemedicine increased during the COVID-19 pandemic. However, the impact on patient satisfaction in the Neuro-oncology population is unknown. This quality improvement project compares outpatient satisfaction before and during the COVID-19 pandemic as well as in-person versus telemedicine platforms during the pandemic. METHODS We performed an IRB-exempt retrospective analysis of aggregate de-identified outpatient satisfaction scores among Neuro-oncology patients seen at The Preston Robert Tisch Brain Tumor Center (PRTBTC) at Duke University. The Clinician & Group Consumer Assessment of Healthcare Providers and Systems (CG-CAHPS) is a survey developed and distributed by Press Ganey Associates, and is the most widely used outpatient satisfaction survey in the United States. We compared pre-COVID-19 CG-CAHPS scores from patients who received in-person care at the PRBTC between April 2019 and March 2020 to COVID-19 pandemic CG-CAHPS scores (i.e. those who received either telemedicine or in-person care at the PRTBTC) from April 2020 to March 2021. RESULTS Approximately 1448 surveys were completed for both in-person and telemedicine visits. During the pandemic, 48.6% of surveys represented telemedicine, with monthly variations from 84.6% (April 2020) to 21.4% (March 2021). Patient satisfaction scores pre-COVID-19 were similar to those during the pandemic: overall provider rating from 0-10 (9.28 v 9.36), knowledge of medical history (96.9% v 95.4%), listens carefully (96.6% v 96.9%), shows respect (97.2% v 98.1%), and time spent (93.2% v 95.5%). During the COVID-19 pandemic, in-person and telemedicine demonstrate similar levels of satisfaction: overall provider rating from 0-10 (9.29 v 9.48), knowledge of medical history (94.9% v 96.1%), listens carefully (95.4% v 99.0%), shows respect (97.5% v 99.0%), and time spent (94.7% v 96.7%). CONCLUSION Outpatient satisfaction prior to and during the COVID-19 pandemic was similar. Patients reported similar satisfaction between in-person and telemedicine platforms. We support the ongoing use of telemedicine for outpatient Neuro-oncology.

Introduction The cytomegalovirus (CMV) antigen, pp65, is ubiquitously expressed in malignant glioma and medulloblastoma but not in healthy brain. The objective of this Phase I trial (NCT03299309) was to assess the safety and feasibility of a novel pp65 peptide vaccine (PEP-CMV) in children and young adults with recurrent medulloblastoma and malignant glioma. Methods Vaccines contain a synthetic long peptide (SLP) of 26 amino acids encoding multiple potential class I, class II, and antibody epitopes of CMV pp65 across several haplotypes. This SLP is administered as an emulsion in Montanide ISA 51. Patients receive a single course of temozolomide to induce lymphopenia, tetanus/diphtheria toxoid site preconditioning, then vaccines administered intradermally every two weeks for 3 doses, then monthly. Results To date, 22 patients have been enrolled. Diagnoses include medulloblastoma (n=2), glioblastoma (n=12), anaplastic oligodendroglioma (n=2), anaplastic astrocytoma (n=3), and malignant glioma NOS (n=3). Mean number of prior treatment regimens is 4.9 (range 1–12). Mean age is 22yo (range 6–35) and 45% of patients are male. The median KPS is 80. The median number of vaccines given at time of analysis is 3.3 (range 1–12). There have been no ≥ 3 Grade toxicities related to the vaccine. One patient developed nausea, vomiting, palpitations, and tachycardia after vaccination and had elevated inflammatory cytokines consistent with cytokine release syndrome. Median PFS is 2.5 months (95% CI: 1.7,4.5) and median OS is 6.5 months (95% CI 3.3, 7.9). Immune response to pp65 as determined by ELISpot was found in 75% of patients. On MRI 6 of the 11 evaluable patients have had at least stable disease with three of those having a partial response. Conclusions Preliminary results demonstrate that PEP-CMV is well-tolerated and elicits an immune response in heavily pretreated, multiply recurrent patients. A multi-institutional Phase II trial is scheduled to open fall 2021.

BACKGROUND The intent of this investigation is to validate a novel, high-affinity epidermal growth factor receptor (EGFR) chimeric antigen receptor (CAR) T-cell product for adoptive immunotherapy of EGFR-expressing malignancies of the central nervous system (CNS). Wild type EGFR is ubiquitously expressed on glial tumors in both children and adults, and the majority of solid tumors that metastasize to the CNS but is not expressed on healthy CNS tissues. EGFR and its isoform mutant, EGFRvIII, are hyperactivated or overexpressed receptor tyrosine kinases described in many human cancers. D2C7 is a recombinant monoclonal antibody short chain variable fragment (scFv) that binds to both wild type EGFR and EGFRvIII. We hypothesize that D2C7 adapted as a CAR on primary human T cells will generate potent, cytotoxic activity against EGFR-expressing tumors in vivo. METHODS In vitro interferon gamma release assays comparing the D2C7 CAR to the EGFRvIII CAR have proven that D2C7 CAR-T cells have high specificity and potent cytotoxicity against established murine glioblastoma (GBM) tumor cell lines, expressing both EGFR and EGFRvIII. Next steps include pre-clinical in vivo testing of the D2C7 CAR-T cells in murine models of CNS tumors expressing EGFR/EGFRvIII such as GBM, non-small cell lung carcinoma (NSCLC), breast carcinoma, and melanoma. CONCLUSIONS To improve and validate the effectiveness of CAR T-cell therapy for EGFR-expressing CNS tumors, our team has designed a high-affinity CAR-T cell that targets both EGFRvIII and wild-type EGFR, known as a D2C7 CAR-T cell. This investigation has established pre-clinical anti-tumor activity of D2C7-CAR T cells in vitro and we plan to present more mature data regarding efficacy in orthotopic murine models of GBM, NSCLC, breast carcinoma, and melanoma at the meeting this Fall.

Background & Aim Early clinical trials have demonstrated the safety of chimeric antigen receptor (CAR) T cells targeting glioblastoma (GBM), however, their efficacy remains limited by multiple obstacles including the highly immunosuppressive tumor microenvironment. These adoptively transferred CAR T cells are susceptible to inhibition via the engagement of inhibitory receptors on their surface including PD1, CTLA4, LAG3 and BTLA. The recruitment of Src homology region 2-containing protein tyrosine phosphatase 2 (SHP2) to the immune synapse upon engagement of these co-inhibitory receptors may represent a common mechanism of T cell inhibition. Upon its recruitment and activation, SHP2 dephosphorylates key stimulatory signaling molecules, thus limiting T cell activation. We hypothesized that disrupting SHP2 expression will simultaneously offset multiple co-inhibitory pathways, thereby improving the anti-tumor activity of CAR T cells. Methods, Results & Conclusion CRISPR/Cas9 technology was used to knockout (KO) SHP2 from human T cells. Retroviral vector transduction was used to express a clinically-utilized second generation CAR (with a CD28 signaling endodomain) targeting HER2. The phenotype of wild-type and edited CAR T cells was investigated using mass cytometry and confirmed with flow cytometry. Their function was tested in vitro using xcelligence (an electrical impedance-based long-term cytotoxicity assay) and in vivo in an orthotopic xenograft mouse model of GBM. Efficient SHP2 KO in human T cells was verified using western blotting. The Inference of CRISPR Efficiency (ICE) Assay confirmed efficient editing of the PTPN11 gene encoding SHP2. An anti-HER2 CAR was efficiently expressed in the SHP2KO T cells. SHP2 deletion did not significantly affect T cell expansion, proliferation or phenotypic profile. However, SHP2KO CAR T cells eliminated LN229 cells (a GBM cell line) in vitro more efficiently compared to wild-type CAR T cells. In vivo, SHP2KO CAR T cells showed better control of engrafted LN229 tumor cells and improved the survival of treated mice in comparison to wild-type CAR T cells. In conclusion, these results suggest that SHP2 may limit the function of CAR T cells and that SHP2 deletion may improve their anti-GBM activity.

With a bleak prognosis for malignant glioma, maintaining quality of life (QoL) and decreasing distress of the patient are important in the clinical care of the patient. Mindfulness meditation is a mind-body therapy that has been recently investigated in the oncology field as a non-pharmacological strategy to ameliorate cancer symptoms and to improve QoL. This practice has not been studied in the primary brain tumor population. We initiated a pilot study among newly diagnosed brain tumor patients with the hypothesis that mindfulness meditation practice may benefit the patient by decreasing stress and anxiety and provide a means to cope with their new diagnosis. The specific aim of this pilot study is to determine the feasibility of a mindfulness meditation program to this population during standard of care chemoradiation and to determine whether it merits additional research in a subsequent trial. The intervention consists of six weekly one hour telephone-based mindfulness sessions followed by one in- person mindfulness session consisting of: mindfulness and healing, understanding stress, abiding in kindness, working with difficult emotions, finding peace, going forward and living fully. Subjects are provided with downloadable guided meditations. We plan to enroll fifteen newly diagnosed WHO grade III or IV malignant glioma subjects prior to their 6 week chemoradiation course. We will determine the percentage of subjects approached vs enrolled, number of sessions that each subject attends, completion of study questionnaires and satisfaction of the subjects. QoL surveys include: Functional Assessment of Cancer Therapy- Brain, Functional Assessment of Cancer Therapy- Cognitive Function, Pittsburgh Sleep Quality Index, Functional Assessment of Chronic Illness Therapy-Fatigue and the Five Facet Mindfulness Questionnaire – short form. 13 subjects have been approached and 8 signed consent over a two-month period. We will provide final study results at time of presentation.

BACKGROUND H3 K27M-mutant diffuse midline glioma (DMG) is invariably lethal. Viruses naturally engage innate immunity, induce antigen presentation, and mediate CD8 T cell priming against foreign antigens. Polioviruses, in particular, are uniquely tropic for dendritic cells (DC) and potently activate DC, inducing Th1-dominant cytokine profiles, CD8 T cell immunity, and enhanced epitope presentation. Thus, poliovirus is ideally suited for vectored delivery of signature tumor neoantigens, e.g. the H3 K27M feature of DMG. However, poliovirus vector design is inherently limited by genetic instability and the underlying neuropathogenicity of poliovirus. METHODS We created a genetically stable, polio:rhinovirus chimera vector devoid of neuropathogenicity and modified for stable expression of the HLA-A2 restricted H3.3 K27M antigen (RIPO (H3.3)). RESULTS RIPO(H3.3) infects, activates, and induces H3.3K27M antigen presentation in DCs in vitro. Given intramuscularly in vivo, RIPO(H3.3) recruits and activates DCs with Th1-dominant cytokine profiles, efficiently primes H3.3K27M-specific CD8 T cells, induces antigen-specific CD8 T cell migration to the tumor site, delays tumor growth, and enhances survival in murine tumor models. CONCLUSION This novel approach leverages the unique ability of polioviruses to activate DCs while simultaneously introducing the H3.3 K27M antigen. In this way, DCs are activated optimally in situ, while being simultaneously infected to express/present tumor antigen. RIPO(H3.3), given by intramuscular injection, will be evaluated in a clinical trial for children with H3 K27M-mutant diffuse midline glioma.

BACKGROUND Pediatric neuro-oncology (PNO) survivors suffer long-term physical and neurocognitive morbidity. Comprehensive care addressing late effects of brain tumors and treatment in these patients is important. Clinical guidelines offer a framework for evaluating late effects, yet lack of extended follow-up is a significant barrier. The electronic health record (EHR) allows novel and impactful opportunities to construct, maintain, and leverage survivorship cohorts for health care delivery and as a platform for research. METHODS This survivorship cohort includes all PNO cases ≤18-years-old reported to the state-mandated cancer registry by our institution. Data mining of the EHR for exposures, demographic, and clinical data identified patients with lack of extended follow-up (>1000 days since last visit). Explanatory variables included age, race/ethnicity, and language. Primary outcome included date of last clinic visit. RESULTS Between January 1, 2013 and December 31, 2018, there were 324 PNO patients reported to our institutional registry with ongoing analysis to identify the specific survivorship cohort. Thirty patients died with an overall mortality of 9.3%. Two-hundred-and-sixteen patients were seen in PNO clinic, of which 18.5%% (n=40) did not receive extended follow-up. Patients without extended follow-up were an average of 3.5 years older up (p CONCLUSION Integration of EHR and cancer registry data represents a feasible, timely, and novel approach to construct a PNO survivorship cohort to identify and re-engage patients without extended follow-up. Future applications include analysis of exposures and complications during therapy on late effects outcomes.

BACKGROUND Recurrent medulloblastoma and malignant glioma are lethal tumors that are virtually incurable. The cytomegalovirus (CMV) antigen pp65 is ubiquitously expressed on medulloblastoma and malignant glioma but not on healthy brain. We evaluated autologous CMV pp65 RNA-pulsed dendritic cell (DC) vaccines in children and young adults in a phase I trial. METHODS Circulating monocytes were harvested using leukapheresis, differentiated into DCs, matured, and pulsed with pp65 RNA using electroporation. DCs were packaged into vaccines (2x107DC/vaccine) and administered intradermally following tetanus-diphtheria toxoid site preconditioning every 2 weeks x3, then monthly. The primary objectives of the study were to establish the feasibility of generating at least 3 vaccines and safety. An exploratory objective was to evaluate the ability of vaccination to create and enhance patient pp65-specific T cell responses. RESULTS Eleven patients were enrolled with medulloblastoma (n=3) or glioblastoma (n=8). Ages ranged from 9–30 years old (mean 15.5y). Ten of 11 patients (91%) generated at least 3 vaccines (mean 6.2). Eight patients received at least 3 vaccines. To date, 4 patients have received all generated vaccines without progression, 4 patients have progressed, and 2 patients are still receiving vaccines. There have not been any severe adverse events probably or definitely related to vaccines. More mature data will be presented at ISPNO. CONCLUSIONS Leukapheresis and monocyte differentiation is a feasible strategy for generating adequate DCs for active immunization in children with malignant brain tumors. CMV pp65 RNA-pulsed DCs are well-tolerated and immunogenic. Efficacy endpoints will be evaluated in a subsequent phase II trial.

Background: Triple Negative Breast Cancer (TNBC) refers to an aggressive subtype of breast cancer negative for HER2, estrogen and progesterone receptors. Lacking these receptors, individuals with TNBC do not benefit from many of the targeted therapies for breast cancer. Tumor endothelial marker 8 (TEM8), originally identified as a tumor endothelium associated antigen, has more recently been implicated in TNBC pathogenesis and as a marker of breast cancer stem like cells. Here we report that T cells expressing a TEM8-specific chimeric antigen receptor (CAR) serve as a novel approach to target both TNBC cells and its supporting endothelium. CARs combine the specificity of a monoclonal antibody with the signaling properties of a T cell. Methods: We designed two novel TEM8-specific CAR molecules. A CAR molecule containing an exodomain derived from the anti-TEM8 L2 antibody, followed by CD28 and CD3-zeta signaling domains (second generation CAR) and CD28, 41BB and CD3-zeta signaling domains (third generation CAR), respectively. Retroviral transduction was used to express the TEM8 CAR transgene constructs on HEK 293T cells, then on primary T cells. Results: Immunofluorescence staining revealed that in a panel of primary TNBC breast cancer samples, TEM8 was overexpressed in comparison to normal adjacent breast tissue (6/6). Costaining with the pan-endothelial cell marker CD31 revealed that this overexpression was not confined to the endothelial compartment, but also present on tumor parenchymal cells. The immortalized TNBC cell lines (MDA-MB-231, MDA-MB-436, MDA-MB-468 and Hs578T) expressed endogenous levels of TEM8 protein as revealed by western blot. Greater than 90% transduction of primary human T cells was achieved using both of our CAR constructs, as detected by flow cytometry. TEM8 specific T cells displayed significantly higher killing of TEM8 positive TNBC and tumor endothelial cells (2H11 and bEND.3) in standard four hour chromium release assays when compared to both non-transduced or irrelevant (CD19) CAR T cells and secreted immunomostimulatory cytokines upon encounter of TEM8 positive cells in coculture assays. In a vascularized xenograft model, MDA MB468 cells were injected subcutaneously with matrigel into athymic nude mice and followed via bioluminescence imaging over the course of two months. Established tumors were treated with either, second or third generation TEM8 specific T cells, HER2 specific T cells, non-transduced T cells or left untreated. Relative to non-transduced T cells, TEM8 specific second and third generation CAR T cells significantly delayed tumor growth by 36 days and 50 days, respectively. Conclusion: TEM8 specific CAR T cells could serve as a novel targeted therapy for TNBC and supporting endothelium. Citation Format: Byrd T, Fousek K, Pignata A, Szot C, Bielamowicz K, Wakefield A, Koch J, Landi D, Seaman S, Wels W, Fletcher B, Hegde M, St Croix B, Ahmed N. TEM8 specific CAR T cells serve as a novel targeted therapy for triple negative breast cancer and its supporting endothelium. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr PD3-07.

BACKGROUND D2C7 immunotoxin (D2C7-IT) is a dual-specific recombinant immunotoxin comprising an EGFR-wt and mutant-specific (EGFRvIII) monoclonal antibody fragment and a genetically engineered form of the pseudomonas exotoxin. When injected directly into the tumor mass by convection enhanced delivery (CED), in addition to direct tumor cell killing, immunotoxins induce secondary immune responses by the activation of CD4+ and CD8+ T-cells. We completed a phase 1 dose escalation study of D2C7-IT injected by CED into recurrent WHO grade III-IV MG and identified the phase 2 dose (6,920 ng/mL). Three patients remain in partial response more than 58, 38, and 32 months after a single D2C7-IT intratumoral infusion. As optimal induction of anti-tumor immune responses by immunotoxins is impeded by potent MG-mediated immunosuppression, we are assessing the toxicity of the combination of D2C7-IT with atezolizumab in patients with recurrent WHO grade IV MG. METHODS Eligibility includes adult patients with recurrence of a solitary supratentorial WHO grade IV MG; ≥4 weeks after chemotherapy, bevacizumab or study drug; adequate organ function; and KPS >70%. Patient receives an intratumoral infusion of D2C7-IT and initiates two weeks later atezolizumab at 1200mg, followed by atezolizumab every 3 weeks for up to 2 years. Two cohorts of 3 patients are initially accrued to assess the toxicity of the combination. Assuming accrual continues after the initial two cohorts of 3 patients, an additional 12 patients will be accrued to the study. RESULT The first enrolled patient experienced a grade 3 DLT (grade III ALT elevation) after the first infusion of atezolizumab, but showed a more extensive immunotherapeutic effect by imaging than observed with patients on the D2C7-IT monotherapy trial. Enrollment is ongoing. CONCLUSION D2C7-IT monotherapy has shown prolonged survival and disease control in some patients. We are now evaluating the combination of D2C7-IT with checkpoint inhibition.

BACKGROUND Primary brain tumor patients experience high levels of distress due to their diagnosis and treatment leading to changes in their health-related quality of life (HRQoL). Even with the standard treatment of 6 weeks of radiation with concurrent temozolomide for malignant gliomas, the prognosis remains poor. We sought to provide a new intervention and coping skill for our patients during chemoradiation to alleviate some of their stress and anxiety. Mindfulness meditation is a mind-body therapy used in many other cancer groups which can alleviate stress and improve fatigue, cognition, and sleep. METHODS 15 newly diagnosed malignant glioma subjects started 1-hour weekly phone mindfulness sessions during the 6 weeks of chemoradiation. They completed an in-person mindfulness session and interview upon return to the clinic with a final follow up survey 2 months later. Patient reported outcomes questionnaires were collected at each time point. RESULTS 0/15 subjects completed their post-chemo/in-person visit, and 9 completed their final follow-up surveys 2 months later. Scores for perceived cognition, fatigue, sleep, anxiety, spiritual-well being and mindfulness improved over these time points. Completed HRQoL patient-reported outcome questionnaires with positive trends noted from the mean (SD) post-chemo/in-person visit change from baseline and the follow-up change from baseline were: FACT-Cog perceived Cognitive Impairments subscale 4.11(13.55), 9.14(16.77); FACT-G total -5.48(16.02), 7.02(13.44); FACT-Br total -3.15(24.76), 13.17(23.37); FACIT-F -5(7.68), 0(7.92); and the FACIT-Sp12 -1.38(7.6), 2.17(4.88). Trail making Part A completion times from baseline to follow up decreased over time in 8/9 subjects and 7/9 subjects in Part B. Per the final follow up survey, 7/9 subjects continued their meditation practices after the training sessions and subjectively noted benefits with their stress and anxiety. Conclusion: Despite this small sample size, this mindfulness meditation intervention did positively impact patient-report outcomes of HRQoL in this patient population, thereby larger randomized studies are warranted.

INTRODUCTION BRAF is a RAF-family kinase that regulates MAPK/ERK signaling. Activating BRAF mutations, including V600E, are common in circumscribed low-grade gliomas of childhood and young adulthood, but are uncommon in infiltrative astrocytomas, including glioblastoma. Their role in glioblastoma initiation and progression requires analysis of large datasets given the low frequency (1.0%) in TCGA IDH-wild-type glioblastomas. METHODS Molecular profiling was done on 4679 FFPE gliomas by next-generation sequencing at Caris Life Sciences, of which 3170 underwent RNA-sequencing for gene fusion and 4603 DNA-sequencing for mutations. MGMT promoter methylation was tested by pyrosequencing and PD-L1 IHC was performed using the SP142 clone. RESULTS Excluding variants of uncertain significance, BRAF mutations/fusions were most common in pleomorphic xanthoastrocytoma (PXA; N=12/24, 50%), glioneuronal tumors (N=6/13, 46%), pilocytic astrocytoma (PA; N=15/48, 31%), and ganglioglioma (n=5/18, 28%). BRAF fusions were uncommon (N=17), most frequent in PA (N=8/31, 26%) where they were associated with older age at daignosis (P=0.043), and typically involved KIAA1549 as fusion partner (70%). BRAF-mutated/fused glioblastoma patients (N=59/3126, 2%) were younger than BRAF-wild-type glioblastoma patients (54 versus 59 years, P=3.5x10-3); more likely to be MGMT-unmethylated (75% versus 56%, P=5.0x10-3); and 3x more likely to express PD-L1 (55% versus 17%, P=2.1x10-10). In tumors harboring a V600E mutation, the variant allele frequency (VAF) was similar in glioblastoma as in PXA, PA, ganglioglioma, and glioneuronal tumors (median VAF=35%). CONCLUSIONS BRAF-mutated glioblastoma were 3x more likely to express PD-L1 than BRAF-wild-type glioblastoma. We observed no differences in BRAF V600E clonality in BRAF-mutated glioblastoma compared to BRAF-mutated PXA, PA, ganglioglioma, and glioneuronal tumors, suggesting BRAF mutation is an initiating event in the clonal evolution of a subset of glioblastoma. There is rationale to evaluate combined BRAF inhibition with checkpoint inhibition in BRAF-mutated glioblastoma, potentially synergizing the complete response profile of the former with the durable response profile of the latter.

INTRODUCTION The cytomegalovirus (CMV) antigen, pp65, is ubiquitously expressed in malignant glioma and medulloblastoma but not in healthy brain. The objective of this Phase I trial (NCT03299309) was to assess the safety and feasibility of a novel pp65 peptide vaccine (PEP-CMV) in children and young adults with recurrent medulloblastoma and malignant glioma. METHODS Vaccines contain a synthetic long peptide (SLP) of 26 amino acids encoding multiple potential class I, class II, and antibody epitopes of CMV pp65 across several haplotypes. This SLP is administered as an emulsion in Montanide ISA 51. Patients receive a single course of temozolomide to induce lymphopenia, tetanus/diphtheria toxoid site preconditioning, then vaccines administered intradermally every two weeks for 3 doses, then monthly. RESULTS To date, 17 patients have been enrolled. Diagnoses include medulloblastoma (n=1), glioblastoma (n=9), anaplastic oligodendroglioma (n=2), anaplastic astrocytoma (n=2), and malignant glioma NOS (n=3). Mean number of prior treatment regimens is 4.9 (range 1–12). Mean age is 22yo (range 6–35) and 41% of patients are male. The median KPS is 80. The median number of vaccines given at time of analysis is 3.3 (range 1–12). There have been no ≥ 3 Grade toxicities related to the vaccine. One patient developed nausea, vomiting, palpitations, and tachycardia after vaccination and had elevated inflammatory cytokines consistent with cytokine release syndrome. Median PFS is 2.5 months (95% CI: 0.8, not estimable) and median OS is 6.5 months (95% CI 1.8, not estimable). Interim analysis of immune monitoring bloodwork and perfusion MRI to quantify responses to PEP-CMV has been delayed due to COVID-19. However, adults with GBM who received PEP-CMV (NCT02864368) had significant (p≤0.05) increases in GCSF, GM-CSF, IFN-γ, IL-10, IL-2, IL-8, MIP1-α, and TNF-α levels. CONCLUSIONS Preliminary results demonstrate that PEP-CMV is feasible and well-tolerated in heavily pretreated, multiply recurrent patients.

Early clinical trials have demonstrated the therapeutic potential of chimeric antigen receptor (CAR) T cells against glioblastoma (GBM), but also highlighted the obstacles that need to be addressed to improve their anti-tumor activity. GBM is highly immunosuppressive and thus necessitates endowing adoptively transferred CAR T cells with resistance mechanisms to achieve sustained treatment responses. This is, in part, due to the effect of immune-inhibitory receptors, including PD1, CTLA4, LAG3 and BTLA, that antagonize the tumor-directed T cells. A common mechanism of T cell inhibition involves the recruitment of Src homology region 2-containing protein tyrosine phosphatase 2 (SHP2) to the immune synapse upon engagement of multiple co-inhibitory receptors. SHP2, in turn, de-phosphorylates key signaling proteins involved in T cell activation. We hypothesized that disrupting SHP2 expression will offset multiple co-inhibitory pathways, thereby improving the anti-tumor activity of CAR T cells. Using CRISPR/Cas9 gene editing, we disrupted the SHP2-encoding gene locus, PTPN11, in primary human T cells by generating and testing a library of single-guide RNA (sgRNA). We selected the top candidate that reproducibly reduced the SHP2 protein expression to Citation Format: Khaled Sanber, Zeid Nawas, Vita Salsman, Ahmed Gad, Pretty Rose Matthew, Daniel Landi, Ciaran Lee, Amel Sengal, Rikhia Chakraborty, Sujith Joseph, Ahmed Nabil, Meenakshi Hegde. CRISPR-Cas9 gene editing of inhibitory receptor signaling pathways improves CAR T cell activity against glioblastoma [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2173.

BACKGROUND: Pleomorphic xanthoastrocytoma (PXA) is a rare Grade II and III glioma. Surgical resection is the mainstay of treatment; however, adjuvant therapy is sometimes necessary. Given the rarity of PXA, chemotherapeutic efficacy data is limited. The importance of the BRAF V600E mutation in the context of MAP kinase pathway inhibition is unknown. The purpose of this study was to perform an in vivo screen of a variety to agents to determine efficacy against both V600E mutant and non-mutant PXA. METHODS: The efficacy of bevacizumab, temozolomide, lomustine (CCNU), irinotecan (CPT 11), a tyrosine kinase inhibitor (sorafenib), a selective MEK1/2 inhibitor (cobimetinib), and a BRAF inhibitor (vemurafenib) were assessed in two subcutaneous xenografts: D645 PXA (V600E-mutant) and D2363 PXA (V600E-non-mutant) (n=5–10 mice). Select agents were also assessed in an intracranial model of D2363 PXA (n=6–9). Subcutaneous tumor growth and survival were the endpoints. RESULTS: Temozolomide, bevacizumab, CPT 11, and sorafenib significantly inhibited subcutaneous tumor growth in both V600E-mutant and V600E-non-mutant models (P

Pleomorphic xanthoastrocytoma (PXA) is a rare Grade II and III glioma. Surgical resection is the mainstay of treatment, however, adjuvant therapy is sometimes necessary. Given the rarity of PXA, chemotherapeutic efficacy data is limited. The importance of the BRAF V600E mutation in the context of MAP kinase pathway inhibition is unknown. The purpose of this study was to perform an in vivo screen of a variety to agents to determine efficacy against both V600E mutant and non-mutant PXA. The efficacy of bevacizumab, temozolomide, lomustine (CCNU), irinotecan (CPT 11), a tyrosine kinase inhibitor (sorafenib), a selective MEK1/2 inhibitor (cobimetinib), and a BRAF inhibitor (vemurafenib) were assessed in two subcutaneous xenografts: D645 PXA (V600E-mutant) and D2363 PXA (V600E-non-mutant) (n = 5–10 mice). Select agents were also assessed in an intracranial model of D2363 PXA (n = 6–9). Subcutaneous tumor growth and survival were the endpoints. Temozolomide, bevacizumab, CPT 11, and sorafenib significantly inhibited subcutaneous tumor growth in both V600E-mutant and V600E-non-mutant models (P

BACKGROUND: EGFR is a receptor tyrosine kinase that is hyperactivated or overexpressed in many human cancers. Compared with brain tumors in adults, pediatric tumors harbor few somatic mutations, which reduces the antigenic burden and number of potential molecular targets. Compared to checkpoint agents, therapies that elicit innate-based, inflammatory immune responses appear better able to counter tumor-inherent immunosuppression and instigate adaptive antitumor immunity. D2C7-IT is a dual-specific antibody fragment that has a high affinity for both EGFRwt and EGFRvIII-expressing cells fused to a genetically engineered form of the Pseudomonas exotoxin. D2C7-IT has been used to treat 35 adults with malignant glioma on a phase I trial at Duke. D2C7-IT is well-tolerated and preliminarily appears to prolong survival in some patients. METHODS: We have tested five samples each from several primary pediatric tumor types and found marked, often diffuse EGFRwt overexpression in ependymoma, oligodendroglioma, malignant glioma, low-grade glioma, and pleomorphic xanthoastrocytoma. Because of this data and the potential that D2C7-IT will be even more effective against pediatric tumors with a lower tumor mutational burden (TMB), we are evaluating D2C7-IT delivered by intratumoral infusion in children with any of the above relapsed tumors in a phase I trial. CONCLUSIONS: As the primary objective, this study will establish the safety and feasibility of D2C7-IT treatment in children with an EGFRwt-expressing brain tumor. As exploratory objectives, we are assessing the pre-treatment TMB in these pediatric brain tumors and its impact on response to D2C7-IT treatment.