Search

BACKGROUND Anti-PD1 therapy alone in rGBM is of limited efficacy seen in three randomized trials. VEGF is upregulated proangiogenic growth-factor in GBM that contributes to tumor-associated immunosuppression. Preclinical data suggests a potential dose effect of anti-VEGF therapy on immunomodulation. Hence, a combination of anti-PD1 and anti-VEGF is promising approach. METHODS 90 patients with GBM at first recurrence were randomized (1:1) to nivolumab (240 mg IV Q2 weeks) with bevacizumab at standard (10 mg/kg; Arm A) or at low dose (3 mg/kg; Arm B) IV Q2 weeks. Stratification included extent of resection, age, performance-status, and MGMT methylation status. Progression-free survival (PFS) and overall survival (OS) were compared. RESULTS 90 patients (Median age 60.6 years, 67.8% male, median KPS 80) were enrolled between May 2018 and Jan 2020. Patients were followed in median 7.7 months (Range 0.7, 28.2). 35 patients were MGMT methylated and 53 patients were MGMT not hypermethylated and 2 were indeterminate. Overall survival was similar between arm A and arm B (1 year: 41.1 vs 37.7%, p = 0.14), while OS was better for arm A in age > 60 compared to arm B (At 1-year: 46.2% vs 23.8%; Median: 10.6 vs 5.9 months; P = 0.046). OS was not statistically different in the two arms for patients with age ≤ 60 years (At 1-year: 35.6% vs 56.4; Median 8.0 vs 12.4 months; P = 0.90). Most frequent toxicities ( >20%) included fatigue (45.6%), proteinuria (34.4 %), diarrhea (28.9%), hypertension (23.3%) and lipase increase (21.1%). Toxicities in grade 3-4 were hypertension (7.8%), fatigue (5.6) and other non-neurological toxicities including DVT, PE, infection, and abnormal liver function. CONCLUSIONS Overall PFS and OS rates appear similar for nivolumab with either standard or low-dose bevacizumab compared bevacizumab monotherapy. Nivolumab with standard bevacizumab benefits patients older than 60 years old. Biomarkers of response data will be presented.

Over 60% of glioblastomas retain wild-type p53, resulting in potential susceptibility to MDM2 inhibitors. These molecules disrupt the interaction between p53 and its negative regulator MDM2, allowing downstream pathway signaling and cell fate decisions including growth inhibition and death resulting from cellular stress. We have analyzed clinical samples from 10 patients newly diagnosed with glioblastoma multiforme (GBM) and treated with the MDM2 inhibitor KRT-232. We detected upregulation of CDKN1A transcript (a target of p53) in all p53 wild-type tumors (8 of 10), but not in p53-mutant tumors (2 of 10). In patient-derived cell lines, treatment with KRT-232 at the clinically detected concentration was only sufficient to stall tumor growth. Cell death via apoptosis can be achieved when MDM2 inhibition is combined with the chemotherapeutic agent temozolomide. As the effects and resistance mechanisms of MDM2 inhibition remain poorly understood in GBM, we have additionally performed genomic and transcriptomic analyses in patient-derived cell lines to better characterize sensitive tumors and identify putative biomarkers of drug response. Dose response curves and growth assays showed that tumors with inactivating p53 mutations are highly resistant to treatment, but those that retain wild-type p53 exhibit various degrees of drug sensitivity. This suggests that other factors, in addition to p53 mutational status, mediate response to MDM2 inhibition in gliomas. Transcriptional analyses of patient samples following drug treatment suggest that cell division, chromatin reorganization, cell differentiation state and immune response programs become deregulated under MDM2 inhibition and in the absence of p53-inactivating mutations.

New precision medicine therapies are urgently required for glioblastoma (GBM). However, to date, efforts to subtype patients based on molecular profiles, have failed to direct treatment strategies. We hypothesized that interrogation of the GBM tumor microenvironment (TME) and identification of novel TME-specific subtypes could inform new precision treatment strategies. To this end, a refined and validated microenvironment cell population (MCP)-counter method was applied to > 800 GBM patient tumours and validated by multiplex-immunohistochemistry. The MCP-counter deconvolution method interrogates the TME composition from transcriptomic data. Using this refined method, we classified the GLIOTRAIN(www.gliotrain.eu) IDHwt GBM cohort (n=123) into 3 novel clusters characterised by differences in TME composition and subsequently validated findings in the TCGA (n=69), CGGA (n=72) and DUKE (unpublished)(n=162) cohorts. TMEHigh tumours (30%) displayed elevated immune populations, functional orientation markers, immune checkpoint genes, and upregulated immunoregulatory pathways. Moreover, tertiary lymphoid structures were a feature of TMEHigh/mesenchymal+ patients. TMEMed (46%) tumours displayed heterogeneous immune populations and upregulated neuronal signalling pathways. TMELow (24%) tumours represented an ‘immune-desert’ group, high EGFR mutation frequency and upregulated EGFR signalling pathways. Longitudinal analysis of the GLASS cohort revealed TME-subtype transitions upon recurrence, influenced by TME composition changes. Finally, assessment of three GBM immunotherapy clinical trial cohorts revealed that TMEHigh patients treated with neo-adjuvant anti-PD1 have a significantly improved survival (P=0.04). Moreover, TMEHigh patients treated with anti-PD1 and an oncolytic virus (PVSRIPO) in the adjuvant setting, showed a trend towards improved survival (P=0.15 and P=0.056 respectively). Overall, we have established a novel TME-based classification system for application in intracranial malignancies. This system may be used to better inform a precision targeting approach in the brain tumour setting. For example, we hypothesise that patients bearing TMELow tumours may be amenable to neoadjuvant anti-TIM3 + EGFR inhibitor, TMEMed to anti-angiogenic immunotherapy, and TMEHigh patients to neoadjuvant anti-PD1 + anti-CTLA4.

Patients with glioblastoma have a poor prognosis despite extensive efforts to develop new treatments. Standard of care for newly diagnosed patients is surgery followed by radiotherapy plus temozolomide. However, temozolomide only provides a clinical benefit to patients who have glioblastomas with a methylated O(6)-methylguanine-DNA methyltransferase (MGMT) gene promotor. Disease recurrence is inevitable and subsequent treatments have poor outcomes due to limited efficacy and a lack of established therapeutic regimens. [68Ga]Ga-DOTA-TATE is a radioligand imaging agent that selectively binds to somatostatin receptors (SSTRs) and is used with positron emission tomography (PET) for the molecular imaging of SSTR-positive neuroendocrine tumors. Glioblastoma tumoral PET scans have shown moderate uptake of [68Ga]Ga-DOTA-TATE. The radioligand therapy [177Lu]Lu-DOTA-TATE has the same SSTR-targeted ligand and demonstrated promising clinical activity in a pilot study in patients with Grade III/IV gliomas. This Phase 1b open-label dose-finding study (NCT05109728) will determine the recommended [177Lu]Lu-DOTA-TATE dose in three different groups of glioblastoma (newly diagnosed with methylated MGMT promoter [group 1], newly diagnosed with unmethylated MGMT promoter [group 2], and recurrent disease [group 3]). All participants will be scanned with [68Ga]Ga-DOTA-TATE imaging during screening and, for each group, approximately 15 participants will be enrolled in consecutive cohorts of 3–6 participants. All participants will receive up to 6 administrations of [177Lu]Lu-DOTA-TATE (initial dose 150 mCi with 3 provisional dose levels up to 250 mCi) using the Bayesian Optimal Interval design. Group 1 will receive [177Lu]Lu-DOTA-TATE every 4 weeks with concomitant radiotherapy and temozolomide, followed by temozolomide maintenance. Group 2 will receive [177Lu]Lu-DOTA-TATE every 4 weeks for 3 doses with radiotherapy then every 3 weeks as a single agent. Group 3 will receive [177Lu]Lu-DOTA-TATE only, every 3 weeks. The primary endpoint is incidence of dose limiting toxicity. Secondary endpoints include overall objective status (modified RANO criteria), progression free survival, overall survival and safety.

EO2401 includes microbial-derived, synthetically produced HLA-A2 restricted peptides with molecular mimicry to antigens (IL13Rα2, BIRC5 and FOXM1) upregulated in glioblastoma, and the CD4 helper peptide UCP2. Patients with glioblastoma at first progression received EO2401 (300µg/peptide, q2weeks x4 then q4weeks), EO2401+nivolumab (3mg/kg q2weeks), or E02401+nivolumab+bevacizumab (10mg/kg q2weeks). Cohort-1 included EO2401x2 then EO2401+nivolumab. EO2401+nivolumab was evaluated in Cohort-2a, as adjuvant treatment in Cohort-2b, and as neoadjuvant/adjuvant treatment in Cohort-2c. Cohort-3 assessed EO2401+nivolumab+bevacizumab. Part 1 included 40 patients (Cohort-1/3, Cohort-2a/23, Cohort-2b/3, Cohort-3/11). Part 2 allowed low-dose-bevacizumab (5mg/kg q2weeks) for symptomatic edema and enrolled 38 patients (Cohort-1/18, Cohort-2a/15, Cohort-2b/3; and recruiting Cohort-2c/2 target 6, Cohort-3/0 target 15).Safety assessment of part 1 showed EO2401+nivolumab+/-bevacizumab to be well tolerated with EO2401 associated toxicity limited to local administration site reactions (48%; all grade 1-2). The nivolumab-/bevacizumab-toxicity was consistent with historical single-agent data. Strong CD8 T cell ELISPOT responses against the 3 vaccine peptides and cross-reactivity against targeted antigens was demonstrated in the majority of evaluable patients. Immune response was confirmed with tetramer staining of specific CD8 either ex vivo or after in vitro stimulation. For part 1, median progression-free survival (mPFS), and median survival (mOS) for EO2401+nivolumab (Cohorts-1/2/2b, n=29 median follow-up [mFU] 14.0 months) were 1.8 and 10.6 months. Patients on EO2401+nivolumab+bevacizumab (n = 11 mFU 9.6 m) had mPFS 5.5 months and 9 patients alive 7-12.4 months. Objective Response Rate/Disease Control Rate for EO2401+nivolumab and EO2401+nivolumab+bevacizumab was 10%/34% and 55%/82%.Median treatment duration for Cohort-2a part 1 was 6.1 weeks (1/23 on treatment), while it was 10.0 weeks (8/15 on treatment) for Cohort-2a part 2. Overall, in part 2, 36% received low-dose-bevacizumab.EO2401 generated strong immune responses and was well tolerated. Addition of standard bevacizumab to EO2401+nivolumab improved PFS and tumor response. Symptom driven low-dose-bevacizumab supported longer treatment durations. Outcome of study part 2 will be presented.

BACKGROUND Adverse events (AE) including seizures cause significant morbidity in patients with GBM. We propose a novel method for assessing genomic predictors of AEs using results from a clinical targeted sequencing platform with variant function analysis. METHODS We identified 1,011 consecutive adult patients with newly diagnosed, histologically confirmed IDH-wildtype GBM with targeted exome NGS (Oncopanel) at Dana-Farber Cancer Institute from 2013-2019. Seizure at presentation was retrospectively identified as an AE. Biologic function (high loss, low loss, neutral, low gain and high gain) was assigned to variants using a three-tiered approach leveraging a genetic variant database (OncoKB), followed by analysis using protein prediction tools (Sift, Polyphen2 and Provean). Univariate logistic regression was performed for each relevant altered gene against the outcome of interest with false-discovery rate correction. Genes associated with seizure at presentation were included iteratively in a multivariate logistic model including other predictors of the outcome. RESULTS Our analysis included 470 GBM patients with 107 genes and 12 whole chromosome or arm level candidate variants covered by all versions of Oncopanel and with >10% alteration. Seizure at presentation occurred in 143/463 patients (31%) and was associated with EGFR amplification (high gain) (OR: 2.76, 95% CI: 1.4-5.3, p = 0.04). In a multivariate analysis (including age, sex, and preoperative tumor volume), EGFR amplification remained statistically significant (OR: 1.5, 95% CI: 1.0-2.2, p = 0.03). CONCLUSION Genomic biomarkers based on functional variant analysis of a routine clinical panel may predict adverse events in GBM. Seizure at presentation was independently associated with EGFR amplification. Our ongoing analysis will look at predictors of myelosuppression, thromboembolism, pseudoprogression and early progression using a similar approach. Identifying molecular risk factors could improve the management of patients through supportive care and consideration of prophylactic therapies.

BACKGROUND CAN-3110 (rQNestin34.5v2) is an HSV-1 oncolytic viral immunotherapy with one copy of the inflammatory ICP34.5 gene under transcriptional control of the Nestin glioma-specific promoter. We completed a phase 1 sequential dose-escalation trial of CAN-3110 in recurrent high-grade glioma (rHGG). METHODS CAN-3110 was injected intratumorally starting at 1x106 plaque forming units (pfu) and dose- escalated by half log up to 1x1010 pfu in biopsy confirmed rHGG. An expansion cohort of 12 patients was then accrued at 1x109 pfus. Blood and post-injection rHGG were collected. RESULTS 41 rHGG patients were treated (42 separate interventions): median age 56 years (range 27-74); 21 females, 20 males; median baseline KPS 90 (range 70-100). CAN-3110 administration was well-tolerated with no dose limiting toxicities. Median overall survival (mOS) was 11.9 months. Histologic and molecular analyses showed significantly increased T cell infiltration in post treatment samples with elevated T cell and/or B cell receptor (TCR/BCR) transcripts which correlated with patient survival (HR 0.26 for patients with elevated TCR/BCR rearrangements as compared to patients with low). Volumetric analyses of MRI suggest a trend between reduction in the relative change in tumor growth, TCR/BCRs enrichment and survival in CAN-3110 treated patients. CLINICAL IMPLICATIONS Administration of CAN-3110 into rHGG was well tolerated. OS of CAN-3110 treated subjects compare favorably to historical controls. The association of increased TCR/BCR transcripts with survival suggests that CAN-3110 induces T cell responses against rHGG, supporting further clinical development of CAN-3110 viral immunotherapy.

BACKGROUND H3 K27M-mutant diffuse midline glioma is a universally fatal malignancy primarily affecting children and young adults; while radiotherapy (RT) provides transient benefit, no effective systemic therapy is currently available. ONC201, a first-in-class imipridone, is an oral, blood-brain barrier penetrating, selective small molecule antagonist of dopamine receptor D2/3 (DRD2) and agonist of the mitochondrial protease ClpP. An integrated pooled analysis of objective response in ONC201-treated patients enrolled in one of five open-label trials has previously demonstrated efficacy in patients with recurrent disease. This phase 3 trial will be the first randomized, controlled study evaluating ONC201 in patients with H3 K27M-mutant disease. METHODS ONC108 is a randomized, double-blind, placebo-controlled, parallel-group, international Phase 3 study of ONC201 in patients with newly diagnosed H3 K27M-mutant diffuse glioma. Patients will be randomized to receive once-weekly ONC201 or placebo following standard frontline radiotherapy. Primary efficacy endpoints are overall survival (OS) and progression-free survival (PFS) in all participants; PFS will be assessed with the response assessment in neuro-oncology-high grade glioma by blind independent central review. Other objectives include assessments of safety, additional efficacy endpoints, clinical benefit, quality of life, pharmacokinetics, biomarkers, and healthcare resource utilization. Eligible patients will have histologically confirmed H3 K27M-mutant diffuse glioma, a Karnofsky/Lanksy performance status ≥ 70, and completed first-line radiotherapy. Eligibility will not be restricted based on age; however, patients must be ≥ 10 kg at time of randomization. Patients with a primary spinal tumor, diffuse intrinsic pontine glioma, leptomeningeal disease, or cerebrospinal fluid dissemination are not eligible.

BACKGROUND Treatment-related toxicity is common in patients with glioblastoma (GBM) receiving chemotherapy and radiotherapy (RT). Temporalis muscle thickness (TMT) is a biomarker associated with sarcopenia and worse clinical outcomes in GBM, however its relation to treatment toxicity is less studied. We hypothesize that TMT may predict toxicity and survival in GBM patients. METHODS We reviewed consecutive patients with IDH-wildtype GBM treated from 2014-2019 at a single academic center. TMT was retrospectively assessed on T1-weighted MRI scans and dichotomized based upon previously validated sex-specific cutoff values. TMT was measured on baseline MRI scan at time of diagnosis. Cox regression multivariable analysis (MVA) was used to assess survival. RESULTS We evaluated 351 patients with median age of 60y (range 20-94) and median follow-up of 14mo. Most patients were male (59%), baseline KPS >70 (95%), and MGMT unmethylated (55%). After maximal safe resection, most patients received standard (90%) or hypofractionated (10%) RT with concurrent systemic therapy (89%). On MVA, baseline low TMT (HR 1.93, p=0.01), age >65y, baseline KPS, and MGMT-unmethylated status were associated with worse OS. On MVA, baseline low TMT (HR 1.95, p=0.01), age >65y, MGMT-unmethylated status, and discontinuing systemic therapy were associated with worse profession-free survival (PFS). 21 patients did not complete anticipated treatment course of chemoradiation and adjuvant systemic therapy due to toxicity, primarily thrombocytopenia, associated with worse OS on MVA (HR 1.99, p< 0.01). Low TMT was associated with higher risk of stopping treatment due to adverse events (OR 5.25, p< 0.01) independent of age, sex, extent of resection, RT dose on MVA. CONCLUSION Baseline low TMT was associated with worse PFS and OS, and it was associated with treatment interruption due to treatment toxicity in GBM patients. While further validation is needed, TMT may help identify patients who will benefit from aggressive symptom management or treatment deintensification.

Despite major strides in cancer research, care, and therapy, these advances have not been equitable across race and ethnicity. Groups underrepresented in medicine (URM) are more likely to have inadequate preventive screening, increased delays in diagnosis, and poor representation in clinical trials. Notably, Black and Latino Americans represent 29% of the population but only reflect 8% of oncology clinical trial participants. Recent studies have shown that this disparity is also present in neuro-oncology as women, Black, and Latino Americans remain under-accrued in clinical trials. Brain tumor patients already face unique barriers to clinical trial enrollment and completion due to disease-specific conditions–such as impaired motor function, cognition, language deficits, and caregiver dependency–which pose additional difficulties in clinical trial consent, enrollment, and adherence. As part of this collaborative initiative, we evaluated the impact of how a lack of diversity in cancer research is detrimental to scientific discovery and propose interventions focused on improving URM engagement with clinical research. Recommendations include the creation of inclusive trial design at the onset, decreasing barriers to care, expanding trial eligibility, and equitable access to tumor profiling for personalized medical trials. Additionally, setting reasonable metrics and goals for accrual and engagement with patient and community stakeholders will ultimately help to diversify trial participants. Lastly, diversification and inclusion practices within the neuro-oncology workforce, including all personnel involved in clinical research, will help to minimize bias, promote concordant care, and assist with developing sustainable solutions. The diversification of participation in neuro-oncology clinical trials is imperative. The lack of diversity in clinical trials can contribute to improper generalizability of treatment efficacy, resulting in potentially harmful practices. Equitable access and inclusion of URM brain tumor patients will not only enhance research discoveries but will also result in improved patient care for all cancer patients.

The lack of reliable predictive biomarkers to guide effective therapy is a major obstacle for the advancement of therapy for high grade gliomas (HGG), and particularly glioblastoma (GBM), one of the few cancers whose prognosis has not improved over the past several decades. With this pilot clinical trial we provide first in human evidence that drug-releasing intratumoral microdevices (IMD) can be safely and effectively used to obtain patient-specific, high throughput molecular and histopathological data to inform selection of drugs based on their observed antitumor effect in situ. The use of IMD is seamlessly integrated in standard surgical practice during tumor resection. None of the six enrolled patients experienced adverse events related to the IMD, and the retrieved tissue was usable for downstream analysis for 11 out of 12 retrieved specimens. Molecular analysis of the specimens provided, for the first time in humans, preliminary evidence of the robustness of the readout, with strong correlation between IMD analysis and clinic-radiological responses to temozolomide. From an investigational aspect, the amount of information obtained with IMD allows unprecedented characterization of tissue effects of any drugs of interest, within the physiological context of the intact tumor.

BACKGROUND MGMT promoter methylation in IDH-mutant gliomas was associated with improved survival in a recent study (PMID 35386566) but did not account for the updated WHO classification of CNS tumors. We evaluated the prognostic value of MGMT methylation in IDH-mutant gliomas incorporating the 2021 WHO classification. METHODS We retrospectively identified 431 patients with IDH-mutant gliomas treated at a single institution from 2010-2020. Kaplan-Meier method was used to estimate OS and PFS rates. Log-Rank test was used to evaluate differences between groups. RESULTS Median age was 36.2 years. MGMT promoter was methylated in 49.6%, unmethylated in 17.2%, partially methylated in 6.7%, and untested in 26.5%. Histological diagnosis was consistent with astrocytoma in 45.7%, oligodendroglioma in 33.9%, glioblastoma in 16.4%, and oligoastrocytoma in 4%. After accounting for 1p/19q and CDKN2A statuses, 190 patients had an integrated diagnosis of astrocytoma, grade 2 or 3; 94 had astrocytoma, grade 4; and 147 had oligodendroglioma, grade 2 or 3. There were 101 death events. Median OS was 33.36 years and median PFS was 5.67 years in MGMT methylated gliomas, compared to median OS of 12.54 years (p=0.0064) and median PFS of 3.91 years (p=0.0034) in unmethylated tumors. Upon univariate subgroup analysis, MGMT methylation was associated with significantly longer OS in histological astrocytomas, grade 2 or 4. However, when stratifying patients according to 2021 WHO classification of CNS tumors, there was no significant difference in OS between MGMT methylated and unmethylated astrocytomas or oligodendrogliomas, irrespective of WHO grade. CONCLUSION MGMT promoter methylation was associated with prolonged OS in histological astrocytomas, IDH-mutant. However, MGMT status did not impact survival after incorporating 2021 WHO classification of CNS tumors, suggesting that 1p/19q co-deletion and CDKN2A homozygous deletion are stronger prognostic factors in our cohort. The number of survival events was limited; larger datasets are required for more definitive conclusions.

Glioblastoma targeted therapeutics have been challenging to develop due to significant inter- and intra-tumoral heterogeneity. While many activated oncogenes in glioblastoma are subclonal, TERT promoter mutations commonly occur as clonal events and are found in up to 80% of IDH-wildtype glioblastomas. Given the high prevalence and clonal nature of TERT promoter mutations in glioblastoma, telomerase is considered a promising therapeutic target for this deadly cancer. Prior studies have validated this hypothesis, demonstrating that knockout of the transcription factor GABPA, which selectively binds to the mutant TERT promoter, as well as base editing-mediated correction of TERT promoter mutations, are selectively toxic to TERTpromoter mutant glioblastomas. However, an important limitation of this strategy is that cancer cell death does not occur immediately after telomerase ablation, but rather after several cell divisions required to reach critically short telomeres. We therefore hypothesize that telomerase inhibition would only be effective in low tumor burden glioblastomas. In this study, we used CRISPR interference to knock down TERT expression in TERT promoter-mutant glioblastoma cell lines and patient derived models. We then measured cell viability and assessed for features of telomere crisis by measuring telomere length and chromatin bridge formation. Lastly, we used a doxycycline inducible CRISPR interference system to knock down TERT expression in vivo early and late in the tumor formation process. We demonstrated that TERT promoter-mutant glioblastoma cells are sensitive to telomerase inhibition and undergo telomere crisis. In vivo, tumor formation is only inhibited when TERT knockdown is induced shortly after tumor implantation, but not when tumor burden is high. This work supports the idea that telomerase inhibition would be a suitable therapeutic strategy for glioblastoma patients with low tumor burden, for example in the adjuvant setting after surgical debulking and chemoradiation.

Background Although IDH-mutant tumors aggregate to the frontotemporal regions, the clustering pattern of IDH-wildtype tumors is less clear. As voxel-based lesion-symptom mapping (VLSM) has several limitations for solid lesion mapping, a new technique, whole-lesion phenotype analysis (WLPA), is developed. We utilize WLPA to assess spatial clustering of tumors with IDH mutation from The Cancer Genome Atlas and The Cancer Imaging Archive. Methods The degree of tumor clustering segmented from T1 weighted images is measured to every other tumor by a function of lesion similarity to each other via the Hausdorff distance. Each tumor is ranked according to the degree to which its neighboring tumors show identical phenotypes, and through a permutation technique, significant tumors are determined. VLSM was applied through a previously described method. Results A total of 244 patients of mixed-grade gliomas (WHO II–IV) are analyzed, of which 150 were IDH-wildtype and 139 were glioblastomas. VLSM identifies frontal lobe regions that are more likely associated with the presence of IDH mutation but no regions where IDH-wildtype was more likely to be present. WLPA identifies both IDH-mutant and -wildtype tumors exhibit statistically significant spatial clustering. Conclusion WLPA may provide additional statistical power when compared with VLSM without making several potentially erroneous assumptions. WLPA identifies tumors most likely to exhibit particular phenotypes, rather than producing anatomical maps, and may be used in conjunction with VLSM to understand the relationship between tumor morphology and biologically relevant tumor phenotypes.

Background Response to targeted therapy varies between patients for largely unknown reasons. Here, we developed and applied an integrative platform using mass spectrometry imaging (MSI), phosphoproteomics, and multiplexed tissue imaging for mapping drug distribution, target engagement, and adaptive response to gain insights into heterogeneous response to therapy. Methods Patient-derived xenograft (PDX) lines of glioblastoma were treated with adavosertib, a Wee1 inhibitor, and tissue drug distribution was measured with MALDI-MSI. Phosphoproteomics was measured in the same tumors to identify biomarkers of drug target engagement and cellular adaptive response. Multiplexed tissue imaging was performed on sister sections to evaluate spatial co-localization of drug and cellular response. The integrated platform was then applied on clinical specimens from glioblastoma patients enrolled in the phase 1 clinical trial. Results PDX tumors exposed to different doses of adavosertib revealed intra- and inter-tumoral heterogeneity of drug distribution and integration of the heterogeneous drug distribution with phosphoproteomics and multiplexed tissue imaging revealed new markers of molecular response to adavosertib. Analysis of paired clinical specimens from patients enrolled in the phase 1 clinical trial informed the translational potential of the identified biomarkers in studying patient’s response to adavosertib. Conclusions The multimodal platform identified a signature of drug efficacy and patient-specific adaptive responses applicable to preclinical and clinical drug development. The information generated by the approach may inform mechanisms of success and failure in future early phase clinical trials, providing information for optimizing clinical trial design and guiding future application into clinical practice.

Background The Response Assessment in Neuro-Oncology Patient-Reported Outcome (RANO-PRO) working group aims to provide guidance on the use of PROs in brain tumor patients. PRO measures should be of high quality, both in terms of relevance and other measurement properties. This systematic review aimed to identify PRO measures that have been used in brain tumor studies to date. Methods A systematic literature search for articles published up to June 25, 2020 was conducted in several electronic databases. Pre-specified inclusion criteria were used to identify studies using PRO measures assessing symptoms, (instrumental) activities of daily living [(I)ADL] or health-related quality of life (HRQoL) in adult patients with glioma, meningioma, primary central nervous system lymphoma, or brain metastasis. Results A total of 215 different PRO measures were identified in 571 published and 194 unpublished studies. The identified PRO measures include brain tumor-specific, cancer-specific, and generic instruments, as well as instruments designed for other indications or multi- or single-item study-specific questionnaires. The most frequently used instruments were the EORTC QLQ-C30 and QLQ-BN20 (n = 286 and n = 247), and the FACT-Br (n = 167), however, the majority of the instruments were used only once or twice (150/215). Conclusion Many different PRO measures assessing symptoms, (I)ADL or HRQoL have been used in brain tumor studies to date. Future research should clarify whether these instruments or their scales/items exhibit good content validity and other measurement properties for use in brain tumor patients.

Immunotherapy has revolutionized treatment for many hard-to-treat cancers but has yet to produce significant improvement in outcomes for patients with glioblastoma. This reflects the multiple and unique mechanisms of immune evasion and escape in this highly heterogeneous tumor. Glioblastoma engenders profound local and systemic immunosuppression and is remarkably effective at inducing T-cell dysfunction, posing a challenge to any immunotherapy-based approach. To overcome these mechanisms, multiple disparate modes of immune-oriented therapy will be required. However, designing trials that can evaluate these combinatorial approaches requires careful consideration. In this review, we explore the immunotherapy resistance mechanisms that have been encountered to date and how combinatorial approaches may address these. We also describe the unique aspects of trial design in both preclinical and clinical settings and consider endpoints and markers of response best suited for an intervention involving multiple agents.

How the glioma immune microenvironment fosters tumorigenesis remains incompletely defined. Here, we use single-cell RNA-sequencing and multiplexed tissue-imaging to characterize the composition, spatial organization, and clinical significance of extracellular purinergic signaling in glioma. We show that microglia are the predominant source of CD39, while tumor cells principally express CD73. In glioblastoma, CD73 is associated with EGFR amplification, astrocyte-like differentiation, and increased adenosine, and is linked to hypoxia. Glioblastomas enriched for CD73 exhibit inflammatory microenvironments, suggesting that purinergic signaling regulates immune adaptation. Spatially-resolved single-cell analyses demonstrate a strong spatial correlation between tumor-CD73 and microglial-CD39, with proximity associated with poor outcomes. Similar spatial organization is present in pediatric high-grade gliomas including H3K27M-mutant diffuse midline glioma. These data reveal that purinergic signaling in gliomas is shaped by genotype, lineage, and functional state, and that core enzymes expressed by tumor and myeloid cells are organized to promote adenosine-rich microenvironments potentially amenable to therapeutic targeting.

Background ONC201 is a dopamine receptor D2 (DRD2) antagonist that penetrates the blood–brain barrier. ONC201 efficacy has been shown in glioblastoma animal models and is inversely correlated with dopamine receptor DRD5 expression. ONC201 is well tolerated in adult recurrent glioblastoma patients with dosing every 3 weeks and has achieved an objective radiographic response in a patient harboring the H3 K27M mutation. Methods In a window-of-opportunity arm, 6 adult subjects initiated ONC201 prior to re-resection of recurrent glioblastoma with intratumoral concentrations as the primary endpoint. An additional 20 adults with recurrent glioblastoma received single agent weekly oral ONC201 at 625 mg, with progression-free survival at 6 months (PFS6) by Response Assessment in Neuro-Oncology (RANO) criteria as the primary endpoint. Results The window-of-opportunity arm achieved its primary endpoint with intratumoral ONC201 concentrations at ~24 hours following the second weekly dose ranging from 600 nM to 9.3 µM. Intratumoral pharmacodynamics assessed by activating transcriptional factor 4, death receptor 5, and apoptosis induction relative to archival samples were observed with the strongest intensity and uniformity among patients with low DRD5 tumor expression. The primary endpoint of PFS6 by RANO was not achieved at 5% in this molecularly unselected cohort; however, 1 of 3 patients enrolled with the H3 K27M mutation had a complete regression of enhancing multifocal lesions that remained durable for >1.5 years. No treatment modifications or discontinuations due to toxicity were observed, including in those who underwent re-resection. Conclusions Weekly ONC201 is well tolerated, and meaningful intratumoral concentrations were achieved. ONC201 may be biologically active in a subset of adult patients with recurrent glioblastoma.

Background Responses to bevacizumab in glioblastoma (GBM) are not durable. Plasma levels of basic fibroblast growth factor (bFGF) increase at the time of tumor progression. By targeting vascular endothelial growth factor receptor (VEGFR), platelet‐derived growth factor receptor, Src, and FGF receptor pathways, ponatinib may potentially help to overcome some of the putative mechanisms of adaptive resistance. Methods We performed a phase II trial of ponatinib in patients with bevacizumab‐refractory GBM and variants. Adult patients with Karnofsky performance score (KPS) ≥60, measurable disease, and normal organ and marrow function received 45 mg ponatinib daily. No limit on the number of prior therapies but only one prior bevacizumab‐containing regimen was allowed. Primary endpoint was 3‐month progression‐free survival. Plasma biomarkers of angiogenesis and inflammation were evaluated before and after treatment. Results The study closed after the first stage. Fifteen patients enrolled: median age 61 [27‐74]; median KPS 80 [70‐90]; median number of prior relapses 2 [2‐4]. Three‐month progression‐free survival rate was 0, median overall survival was 98 days [95% CI 56, 257], and median PFS was 28 days [95% CI 27, 30]. No responses were seen. The most common grade ≥3 adverse events included fatigue (n = 3), hypertension (2), and lipase elevation (2). Ponatinib treatment significantly increased plasma VEGF, soluble (s)VEGFR1, sVEGFR2, sTIE2, interferon gamma (IFNγ), tumor necrosis factor alpha (TNF‐α), interleukin (IL)‐6, IL‐8, and IL‐10 and decreased sVEGFR2. Conclusions Ponatinib was associated with minimal activity in bevacizumab‐refractory GBM patients. Circulating biomarker data confirmed pharmacodynamic changes and suggested that resistance to ponatinib may be related to an increase in inflammatory cytokines., In this phase II trial, ponatinib was associated with minimal activity in bevacizumab‐refractory glioblastoma patients. Circulating biomarker data confirmed pharmacodynamic changes and suggested that resistance to ponatinib may be related to an increase in inflammatory cytokines.

PI3K-targeting therapy represents one of the most sought-after therapies for glioblastoma (GBM). Several small-molecule inhibitors have been evaluated in clinical trials, however, the emergence of resistance limits treatment potential. Here, we generated a patient-derived glioma sphere–forming cell (GSC) xenograft model resistant to the PI3K-specific inhibitor BKM-120. Integrated RNA sequencing and high-throughput drug screening revealed that the Aurora A kinase (Aurora A)/Polo-like kinase 1 (PLK1)/cyclin-dependent kinase 1 (CDK1) signaling pathway was the main driver of PI3K inhibitor resistance in the resistant xenografts. Aurora kinase was upregulated and pCDK1 was downregulated in resistant tumors from both xenografts and tumor tissues from patients treated with the PI3K inhibitor. Mechanistically, the tyrosine kinase receptor Tie2 physically interacted with FGFR1, promoting STAT3 phosphorylation and binding to the AURKA promoter, which increased Aurora A expression in resistant GSCs. Concurrent inhibition of Aurora A and PI3K signaling overcame PI3K inhibitor–induced resistance. This study offers a proof of concept to target PI3K and the collateral-activated pathway to improve GBM therapy.Significance:These findings provide novel insights into the mechanisms of PI3K inhibitor resistance in glioblastoma.

Purpose: To evaluate the results of the randomized, double-blind, placebo-controlled phase II clinical trial of ICT-107 in patients with newly diagnosed glioblastoma. Patients and Methods: We conducted a double-blinded randomized phase II trial of ICT-107 in newly diagnosed patients with glioblastoma (GBM) and tested efficacy, safety, quality of life (QoL), and immune response. HLA-A1+ and/or -A2+–resected patients with residual tumor ≤1 cm3 received radiotherapy and concurrent temozolomide. Following completion of radiotherapy, 124 patients, randomized 2:1, received ICT-107 [autologous dendritic cells (DC) pulsed with six synthetic peptide epitopes targeting GBM tumor/stem cell–associated antigens MAGE-1, HER-2, AIM-2, TRP-2, gp100, and IL13Rα2] or matching control (unpulsed DC). Patients received induction ICT-107 or control weekly × 4 followed by 12 months of adjuvant temozolomide. Maintenance vaccinations occurred at 1, 3, and 6 months and every 6 months thereafter. Results: ICT-107 was well tolerated, with no difference in adverse events between the treatment and control groups. The primary endpoint, median overall survival (OS), favored ICT-107 by 2.0 months in the intent-to-treat (ITT) population but was not statistically significant. Progression-free survival (PFS) in the ITT population was significantly increased in the ICT-107 cohort by 2.2 months (P = 0.011). The frequency of HLA-A2 primary tumor antigen expression was higher than that for HLA-A1 patients, and HLA-A2 patients had higher immune response (via Elispot). HLA-A2 patients achieved a meaningful therapeutic benefit with ICT-107, in both the MGMT methylated and unmethylated prespecified subgroups, whereas only HLA-A1 methylated patients had an OS benefit. Conclusions: PFS was significantly improved in ICT-107–treated patients with maintenance of QoL. Patients in the HLA-A2 subgroup showed increased ICT-107 activity clinically and immunologically.

Background Whereas much information exists in general oncology regarding the barriers to clinical trial referral, those specific to neuro-oncology are not yet well known. Trial barriers lead to lower patient accrual, which can lead to less-efficient clinical trials and slower improvement of the standard of care, which may negatively effect patient outcomes. Thus, the aim of this study was to determine the clinical trial referral barriers that are specific to neuro-oncology to improve trial accrual rates. Methods An electronic survey was completed by 426 Society for Neuro-Oncology members, of whom 372 are included in this report. Descriptive statistics, including frequencies, means, and proportions, were used to characterize our survey sample. Results Only 22% of participants reported that their center tracks referrals to clinical trials inside as well as outside their own institution, with an estimate of less than 30% of patients referred. The most commonly reported provider-referral barrier was finding ongoing trials in the patient’s geographic area. Providers also perceived that while considering participation in a trial their patients may not qualify for any trials, and if they do, may be unable to travel to the study site for follow-up. Additionally, practice location and provider and institution type all influenced referral patterns. Conclusion Efforts should be made to broaden trial availability and eligibility criteria, improve trial referral tracking, and ensure patients and their caregivers understand the goals and importance of clinical trials to reduce barriers and improve trial participation.

BACKGROUND: H3 K27M-mutant diffuse midline glioma is a fatal malignancy with no proven medical therapies. The entity predominantly occurs in children and young adults. ONC201 is a small molecule selective antagonist of dopamine receptor D2/3 (DRD2/3) with an exceptional safety profile. Following up on a durable response in the first H3 K27M-mutant diffuse midline glioma patient who received ONC201 (NCT02525692), an expanded access program was initiated. METHODS: Patients with H3 K27M-mutant gliomas who received at least prior radiation were eligible. Patients with leptomeningeal spread were excluded. All patients received open-label ONC201 orally once every week. Safety, radiographic assessments, and overall survival were regularly assessed at least every 8 weeks by investigators. As of August 2018, a total of 18 patients with H3 K27M-mutant diffuse midline glioma or DIPG were enrolled to single patient expanded access ONC201 protocols. Among the 18 patients: seven adult (>20 years old) and seven pediatric (

Background Longitudinal measurement of glioma burden with MRI is the basis for treatment response assessment. In this study, we developed a deep learning algorithm that automatically segments abnormal fluid attenuated inversion recovery (FLAIR) hyperintensity and contrast-enhancing tumor, quantitating tumor volumes as well as the product of maximum bidimensional diameters according to the Response Assessment in Neuro-Oncology (RANO) criteria (AutoRANO). Methods Two cohorts of patients were used for this study. One consisted of 843 preoperative MRIs from 843 patients with low- or high-grade gliomas from 4 institutions and the second consisted of 713 longitudinal postoperative MRI visits from 54 patients with newly diagnosed glioblastomas (each with 2 pretreatment “baseline” MRIs) from 1 institution. Results The automatically generated FLAIR hyperintensity volume, contrast-enhancing tumor volume, and AutoRANO were highly repeatable for the double-baseline visits, with an intraclass correlation coefficient (ICC) of 0.986, 0.991, and 0.977, respectively, on the cohort of postoperative GBM patients. Furthermore, there was high agreement between manually and automatically measured tumor volumes, with ICC values of 0.915, 0.924, and 0.965 for preoperative FLAIR hyperintensity, postoperative FLAIR hyperintensity, and postoperative contrast-enhancing tumor volumes, respectively. Lastly, the ICCs for comparing manually and automatically derived longitudinal changes in tumor burden were 0.917, 0.966, and 0.850 for FLAIR hyperintensity volume, contrast-enhancing tumor volume, and RANO measures, respectively. Conclusions Our automated algorithm demonstrates potential utility for evaluating tumor burden in complex posttreatment settings, although further validation in multicenter clinical trials will be needed prior to widespread implementation.

Arterial and venous thromboses are common in glioma patients, both in the perioperative period and throughout the course of the disease. High-grade glioma patients harbor underlying hypercoagulability, which predisposes these high-risk patients with prolonged immobility and neurologic deficits to thrombotic events. Despite the high incidence and recurrent nature of these complications, there is no standardized approach to the management of glioma patients, and many challenges remain. Historically, the perceived risk of intracranial and intratumoral hemorrhage limited the use of anticoagulation, favoring nonpharmacological prophylaxis and treatment. Multiple studies have demonstrated the safety and efficacy of anticoagulation when indicated, with low molecular weight heparin as the preferred short- or long-term treatment. This review will discuss the epidemiology, risk factors, and therapeutic management of both venous and arterial thrombotic complications in glioma.

Summary Background Mutant isocitrate dehydrogenase 1 and 2 (IDH1/IDH2) enzymes produce the oncometabolite D-2-hydroxyglutarate (2-HG). Ivosidenib (AG-120) is a targeted mutant IDH1 inhibitor under evaluation in a phase 1 dose escalation and expansion study of IDH1-mutant advanced solid tumors including cholangiocarcinoma, chondrosarcoma, and glioma. We explored the pharmacokinetic (PK) and pharmacodynamic (PD) profiles of ivosidenib in these populations. Methods Ivosidenib was administered orally once (QD) or twice (BID) daily in continuous 28-day cycles; 168 patients received ≥1 dose within the range 100 mg BID to 1200 mg QD. PK and PD were assessed using validated liquid chromatography-tandem mass spectrometry assays. Results Ivosidenib demonstrated good oral exposure after single and multiple doses, was rapidly absorbed, and had a long terminal half-life (mean 40–102 h after single dose). Exposure increased less than dose proportionally. Steady state was reached by day 15, with moderate accumulation across all tumors (1.5- to 1.7-fold for area-under-the-curve at 500 mg QD). None of the intrinsic and extrinsic factors assessed affected ivosidenib exposure, including patient/disease characteristics and concomitant administration of weak CYP3A4 inhibitors/inducers. After multiple doses in patients with cholangiocarcinoma or chondrosarcoma, plasma 2-HG was reduced by up to 98%, to levels seen in healthy subjects. Exposure-response relationships for safety and efficacy outcomes were flat across the doses tested. Conclusions Ivosidenib demonstrated good oral exposure and a long half-life. Robust, persistent plasma 2-HG inhibition was observed in IDH1-mutant cholangiocarcinoma and chondrosarcoma. Ivosidenib 500 mg QD is an appropriate dose irrespective of various intrinsic and extrinsic factors. Trial RegistrationClinicalTrials.gov (NCT02073994).

BACKGROUND: Whole-brain radiotherapy (WBRT) in patients with brain metastases (BM) is associated with neurocognitive decline. Given its crucial role in learning and memory, efforts to mitigate this toxicity have mostly focused on sparing radiation to the hippocampus. We hypothesized that BM are not evenly distributed across the brain and that several additional areas may be avoided in WBRT based on a low risk of developing BM. METHODS: We contoured 2757 lesions in a large, single-institution database of patients with newly diagnosed BM. BM centroids were mapped onto a standard brain atlas of 55 anatomic subunits and the observed percentage of BM was compared with what would be expected based on that region’s volume. A region of interest (ROI) analysis was performed in a validation cohort of patients from 2 independent institutions using equivalence and one-sample hypothesis tests. RESULTS: The brainstem and bilateral thalami, hippocampi, parahippocampal gyri, amygdala, and temporal poles had a cumulative risk of harboring a BM centroid of 4.83% in the initial cohort. This ROI was tested in 157 patients from the validation cohort and was found to have a 4.1% risk of developing BM, which was statistically equivalent between the 2 groups (P < 1 × 10(–6), upper bound). CONCLUSION: Several critical brain structures are at a low risk of developing BM. A risk-adapted approach to WBRT is worthy of further investigation and may mitigate the toxicities of conventional radiation.

The finding that most grades II and III gliomas harbor isocitrate dehydrogenase (IDH) mutations conveying a relatively favorable and fairly similar prognosis in both tumor grades highlights that these tumors represent a fundamentally different entity from IDH wild-type gliomas exemplified in most glioblastoma. Herein we review the most recent developments in molecular neuropathology leading to reclassification of these tumors based upon IDH and 1p/19q status, as well as the potential roles of methylation profiling and deletional analysis of cyclin-dependent kinase inhibitor 2A and 2B. We discuss the epidemiology, clinical manifestations, benefit of surgical resection, and neuroimaging features of lower-grade gliomas as they relate to molecular subtype, including advanced imaging techniques such as 2-hydroxyglutarate magnetic resonance spectroscopy and amino acid PET scanning. Recent, ongoing, and planned studies of radiation therapy and both cytotoxic and targeted chemotherapies are summarized, including both small molecule and immunotherapy approaches specifically targeting the mutant IDH protein.

2047 Background: Paxalisib, a potent oral selective brain-penetrant small molecule PI3K/mTOR inhibitor, has shown activity in nonclinical brain cancer models and promising phase 1 data in progressive / recurrent high-grade gliomas (NCT01547546). This multicenter phase 2 progressive design trial (NCT03522298) aimed to establish the maximum tolerated dose (MTD) for once-daily (QD) dosing, and to evaluate safety, tolerability, pharmacokinetics (PK), and clinical activity of paxalisib in patients with newly diagnosed glioblastoma and unmethylated MGMT promotor status. Methods: Eligible patients were males or females, aged ≥18 years, who had undergone surgical resection and chemoradiotherapy (Stupp Regimen), and were considered to be progression free before starting adjuvant paxalisib. Stage 1 used a standard 3+3 dose-escalation design to determine the MTD in this population. Stage 2 was a two-arm, open-label, expansion cohort with patients randomized 1:1 to receive paxalisib at the MTD under fed or fasted conditions. In both stages, treatment comprised daily paxalisib administered in 28-day cycles, continuously until disease progression or unacceptable toxicity. Efficacy analyses are based on investigator review and from date of diagnosis. Results: Patients (n = 30; 70.0% males, 83.3% white, mean age 58.5 years) had a mean time since diagnosis of 3.75 months. The majority (n = 29) received between 1 and 6 treatment cycles and one received 29 cycles. In Stage 1 (n = 9), an MTD of 60mg was established on the dose-limiting toxicities of hyperglycemia (n = 1) and stomatitis (n = 1) at 75mg. Paxalisib at 60mg was well-tolerated and adverse events were consistent with other PI3K inhibitor medicines. At the MTD (60mg), the PK profile was linear and dose-proportional with no differences in Tmax and elimination half-life under fed and fasted conditions. For the overall ITT population, the median progression free survival was 8.4 months (RANO) and 8.6 months (mRANO) and the median overall survival was 15.7 months. In a mITT (n = 22 patients treated with 60mg daily and ≥1 post-baseline assessment), the median PFS was 9.6 months (mRANO). Conclusions: The primary study endpoints were met; PK and safety were consistent with prior clinical experience. The MTD showed encouraging clinical activity, prolonging PFS and improving OS. Further efficacy confirmation of paxalisib 60 mg QD in newly diagnosed glioblastoma in a pivotal trial is ongoing (GBM AGILE, NCT03970447). Clinical trial information: NCT03522298.

2014 Background: Cytomegalovirus (CMV) antigens have been reported in over 90% of GBMs. CD4+ and CD8+ T cells are most frequently directed against the gB and pp65 antigens, respectively, which are immunogenic targets in a CMV-based GBM immunotherapeutic. Methods: A total of 20 first-recurrent GBM patients were enrolled, with Karnofsky Performance Status of at least 70, across 2 arms of the Phase IIa extension phase to receive VBI-1901 (a gB/pp65 enveloped virus-like particle [eVLP]) adjuvanted with either GM-CSF (given intradermally) or AS01B (given intramuscularly) (NCT03382977). Patients were vaccinated with VBI-1901 every 4 weeks, with serologic immune-monitoring 2 weeks after each vaccination and surveillance brain MRI scans every 6 weeks. Results: 10 patients (6 women, 4 men) with a median age of 58 (33-67 yrs) were enrolled into the GM-CSF arm and 10 patients (3 women, 7 men) with a median age of 65 (40-67) enrolled into the AS01B arm. The 12-month OS rates for the GM-CSF and AS01B arms were 60% and 70%, respectively; the 18-month OS rate for the GM-CSF arm was 30%, and for the AS01B arm is expected to be 30%-40% (data has not yet matured). Two durable partial responses (locally determined by RANO) have been observed in the GM-CSF arm, with one patient progression-free and on protocol after 2 years with a tumor size reduction of 93% relative to start of treatment. Immunological analyses demonstrate that prolonged, monthly dosing with VBI-1901 does not lead to immunological tolerance. Dynamic boosting and loss in the peripheral blood of CMV-specific CD4 Tem cells after treatment with VBI-1901 formulated with GM-CSF may correlate with tumor responses. Conclusions: The U.S. FDA granted Fast Track Designation to VBI-1901 adjuvanted with GM-CSF in first-recurrent GBM patients, and an expansion of the ongoing trial with this formulation in this patient population, with the addition of randomization with a contemporaneous control arm, is anticipated to begin in H1 2022. Acknowledgement: GlaxoSmithKline Biologicals SA provided the AS01B adjuvant used in this study. Clinical trial information: NCT03382977.

TPS3173 Background: CDKs that govern the G1-S transition of the cell cycle (CDK2, CDK4 and CDK6) are deregulated in many cancers. CDK2 expression, in particular, is associated with worse overall survival in glioblastoma (GB), disease-free recurrence in prostate cancer, and resistance to approved CDK4/6 inhibitors (CDK4/6i) in breast cancer. These provide rationale for inhibition of CDK2/4/6 as a potential novel therapeutic strategy in these cancers. NUV-422 is a potent (low nM) small molecule CDK2/4/6i with limited activity against CDK1, a target potentially associated with toxicities in other CDKi. Preclinical studies have shown that NUV-422 has favorable blood-brain barrier penetration, inhibited growth of multiple glioma cell lines in vitro, and exhibited antitumor activity in GB xenograft models. NUV-422 also exhibited antitumor activity in multiple patient-derived xenograft (PDX) models of HR+ HER2- mBC resistant to CDK4/6i, and PDX models of prostate cancer resistant to anti-androgens. Methods: NUV-422-02 (NCT04541225) is a phase 1/2, first in human, open label, multicenter study to evaluate single-agent NUV-422 (given orally) in patients with advanced solid tumors (r/r HGG, r/r HR+ HER2- mBC, or r/r mCRPC). The Ph 1 dose escalation will use a 3+3 design to evaluate safety, tolerability, and PK of NUV-422 and establish the recommended phase 2 dose (RP2D). Ph 1 also includes a randomized surgical substudy to characterize PK and pharmacodynamics (PD) of preoperative NUV-422 in resected GB tumor tissue. After the RP2D is identified, parallel enrollment into phase 2 expansion cohorts will begin. Cohort 1 will evaluate isocitrate dehydrogenase wild type (IDH-WT) GB. Cohort 2 will evaluate HR+ HER2- mBC (without active brain metastases); Cohort 3 will evaluate mCRPC; and Cohort 4 will evaluate HR+ HER2- mBC with active brain metastases. The Ph 2 primary endpoint is objective response rate. Secondary efficacy endpoints include clinical benefit rate, duration of response, progression-free survival, and overall survival. Response assessments will be based on response criteria appropriate to the tumor type (HGG [RANO]; HR+HER2- mBC [RECIST 1.1 or RANO-Brain Metastases]; mCRPC [RECIST 1.1, PCWG3, prostate-specific antigen decrease]). Blood, urine, or tumor tissue will be obtained to assess safety, PK, PD, and for additional exploratory analyses to characterize NUV-422 mechanism of action. Enrollment was initiated in December 2020, and dose escalation is ongoing. The NUV-422 program will also be expanded in 2022 to include additional studies in mBC and mCRPC in combination with standard of care treatments. Clinical trial information: NCT04541225.

2051 Background: Randomized clinical trials use stringent eligibility criteria to select patients which can raise concerns about generalizability of study results. Recent interest in external controls and new trial designs has increasingly focused on the possible use of real-world data sources. We examined potential differences of survival outcomes in clinical trial and real-world datasets in newly diagnosed glioblastoma. Methods: Patient-level data from 4 independent datasets were analyzed. Non-trial data were derived from an institutional dataset of 453 patients with newly diagnosed glioblastoma treated outside of a clinical trial with standard radiation therapy with concurrent and adjuvant temozolomide at a large academic center. Trial patients included patients on the control arm of several multi-institutional trials (NCT00689221, n = 273; NCT00813943, n = 89; NCT00943826; n = 459) and patients treated on trial at our institution (n = 210). Non-trial patients were compared with each of the 4 clinical trial datasets in pairwise comparisons with Cox regression with adjustments for age, sex, extent of resection, KPS and MGMT status. Results: Patient-level data from 1,484 patients were analyzed. Non-trial patients were older compared to patients in the multi-institutional trials (mean 58.6 vs. 56.1 years (NCT00943826), 53.9 years (NCT00813943), 55.7 years (NCT00689221); p < = 0.001). The non-trial cohort had fewer women (43.5% vs. 35.9%, p = 0.02), greater proportion of lower KPS patients (47% KPS 0.05). Conclusions: Glioblastoma patients treated on multi-institutional clinical trials that were included in our analysis did not have statistically significant differences in survival compared to patients treated outside of a clinical trial at a large academic center after adjustment for relevant variables. Our findings support the possible use of real-world data in the development of external control arms for future trials in newly diagnosed glioblastoma. [Table: see text]

2034 Background: EO2401 (EO) was designed to activate existing commensal memory T-cells cross-reacting with tumor associated antigens (TAAs). EO includes microbial-derived, synthetically produced peptides corresponding to HLA-A2 restricted epitopes with molecular mimicry to three TAAs upregulated in glioblastoma (GB), IL13Rα2, BIRC5 and FOXM1, with the CD4 helper peptide UCP2 and the adjuvant Montanide. Pre-clinically EO generates strong immune responses and cross-reactive CD8 cells recognizing the TAAs. Methods: This ongoing Ph 1/2 trial (NCT04116658) investigates EO (SC q2 wks X 4 then q4 wks), EO with nivolumab (3 mg/kg q2 wks; EN), and EN with bevacizumab (10 mg/kg q2 wks; ENB) among four Cohorts (Cs) of pts with GB at first progression after radiotherapy/temozolomide. After the Ph 1 of EO followed by EN (C1), C2 investigated EN without (C2a) or with (C2b) surgery while C3 investigated ENB (population as C2a). Results: Among 40 treated pts (C1 n = 3, C2a n = 23, C2b n = 3, C3 n = 11), median age was 60, 53% male, 40% had KPS 90-100% and 35% had O6-methylguanine DNA-methyltransferase promotor hypermethylated tumors. All evaluable pts demonstrated strong CD8 T-cell ELISPOT responses against the 3 vaccine peptides, with tetramer staining of specific CD8 detected in 24/25 investigated pts after in vitro stimulation and in 19/20 pts directly ex vivo. Cross-reactivity against targeted TAAs was confirmed in 20/21 pts. Majority of response were detected by week 4 after 1st dose and as early as 2 weeks for some pts. EO, EN, and ENB were well tolerated (max exposure EN 68 wks, ENB 30 wks) with EO associated toxicity limited to local administration site reactions (48%; grade 1-2). The frequency and severity of nivolumab- or bevacizumab-associated AEs was consistent with historical monocompound experience. With a median follow-up of 9.3 months (range, 2.8-15.6), median progression-free survival (PFS), survival at 6 months (OS-6) and at 12 months for EN (C1+C2a+C2b) were 1.8 months (3 ongoing at 5.9, 7.1, and 14.7 months), 85%, and 50.1% (19/29 alive), respectively. With a median follow-up of 3.7 months (range, 2.2-7.2), pts on ENB (C3) have median PFS and OS-6 of 5.5 months (7 ongoing), and 80% (10/11 alive), respectively. ORR for EN and ENB were 10% and 36%, respectively (5 of 7 ongoing). In C2a, 12/23 pts stopped treatment due to neurological symptoms and PD on first MRI (median 5 wks, range 2-8). In C3 (ENB), only 1/11 pts stopped early due to PD. Conclusions: EO2401 generated strong systemic immune responses and was well tolerated in combination with nivolumab +/- bevacizumab. The addition of bevacizumab to EN improved PFS while survival across treatment cohorts is pending ongoing follow-up. To prolong EN exposure that is likely required for therapeutic activity in recurrent GB, the trial has been expanded with additional pts to evaluate low-dose bevacizumab (5 mg/kg q2 wks up to x 6) for early progressive neurological symptoms. Clinical trial information: NCT04116658.

2045 Background: Glioblastoma (GBM) is an aggressive primary tumor with poor prognosis and survival. Patients (pts) experience debilitating symptoms that have a negative effect on quality of life (QoL). A multidisciplinary approach is necessary to facilitate the reduction of morbidity, preserve QoL, and maximize benefits of treatment. Selinexor (SEL) is a first-in class, oral, selective inhibitor of nuclear export that blocks exportin 1 approved for use in multiple myeloma and diffuse large B-cell lymphoma and has shown activity in GBM. Digital measurements in the KING study through wearable sensors and other devices capture actionable daily data at home for improved care, symptom management, and QoL, are reported here. Methods: XPORT-GBM-029 (NCT04421378) is an ongoing phase 1 dose finding study followed by an open-label randomized phase 2, 5-arm trial to evaluate SEL in combination with standard therapies for newly diagnosed and recurrent GBM (n = 350): radiation+SEL /radiation and temozolomide; radiation and temozolomide±SEL; lomustine±SEL; bevacizumab±SEL; tumor treating field±SEL. The study is conducted at 18 sites in the US and Canada. GBM progression is assessed by standard clinical and imaging as well as QoL measurements by novel digital tools. Four parameters to determine the impact on QoL (cognitive function, lateralization, fatigue, sleep) are measured remotely by smartwatch and smartphone to continuously measure activity and sleep, and to complete a cognitive battery at baseline and before each MRI. Results: To date, pts wearing the smartwatch had higher compliance during the day for activity and gait measures compared to night for sleep measures. Younger pts had better compliance. Over the course of SEL treatment, changes were observed in balance (characterized by double support % and walking asymmetry) and activity level (characterized by step count and walking distance). Of the pts who participated in the cognitive battery (CANTAB) tests, 2 pts had a minor change in cognition measures including psychomotor and processing speed, episodic and spatial working memory, and executive function after 2 SEL treatment cycles. Overall, the CANTAB measures are stable, which align with the mRANO (MRI) results. The correlation between the CANTAB cognition measures and MRI data will be evaluated once more clinical data become available. Ongoing analyses will apply machine learning and statistical tools to determine potential correlations between digital and clinical data, such as physical examinations, AEs, Karnofsky scores, mRANO, NANO, KPS, and PRO QoL questionnaires. Conclusions: This is the first demonstration of digital measurement feasibility in a longitudinal study of pts with GBM. Digital measurements for pts with GBM could provide information on the impact of SEL-based treatment and functional outcomes in clinical trials and increase communication between clinicians and pts, thereby improving QoL and care management. Clinical trial information: NCT04421378.

2030 Background: Glioblastoma (GBM) and tumor endothelial cells express phosphatidylserine (PS), a highly immunosuppressive membrane phospholipid. PS receptors engage with immune cells, leading to expansion of myeloid-derived suppressor cells (MDSCs) which promote an immunosuppressive and pro-angiogenic tumor microenvironment. Bavituximab (BAV) – a chimeric monoclonal antibody – binds to β2-glycoprotein 1 (β2-GP1) to form a complex of β2-GP1 with PS, resulting in immune activation against tumor cells and anti-angiogenic effects. Pre-clinical data in GBM models suggest synergistic effects of PS blockade, radiation (RT), and temozolomide (TMZ). Here, we present results from a phase II trial (NCT03139916) of BAV, RT and TMZ in GBM patients. Methods: 33 adults with newly diagnosed IDH-wild-type GBM were enrolled and received 6 weeks of RT+TMZ, followed by 6 cycles of TMZ. BAV (3 mg/kg) was given weekly, starting at week 1 of RT+TMZ, for 18 weeks with the option to continue if tolerated. The primary endpoint was the proportion of patients alive at 12 months (OS-12). The null hypothesis would be rejected if OS-12 was ≥ 72%. As an exploratory endpoint, the immune profile in tumor tissue and peripheral blood mononuclear cells (PBMCs) was assessed using nanoString and multispectral immunofluorescence, with the goal to assess on-target effects of BAV in longer vs. shorter surviving patients (split based on median survival). Relative cerebral blood flow (rCBF) from dynamic susceptibility contrast MRI was also obtained. Results: 24 patients were alive at 12 months and OS-12 was 73% (95% CI 59-90%) so the study met its primary endpoint. Median OS was 15.4 months. As best response, 79% of patients had stable disease, 12% had a partial response and 9% had progressive disease. Eight grade 3 or 4 adverse events were seen (no grade 5 AEs). Ten pre-treatment and 7 post-treatment tissue samples were available. Analysis of RNA from pre-treatment tumor specimens showed a significantly positive shift in myeloid-related gene expression in patients with longer survival, with enrichment of 116 and 120 transcripts as well as downregulation of 2 and 1 gene for PFS and OS, respectively. There was no differential expression in PBMCs. Including all tissue samples, there was a marked reduction of MDSCs after BAV compared to time of diagnosis (p = 0.011). Decreased rCBF post-RT/pre-cycle 1 TMZ was associated with improved OS (HR 4.63, p = 0.029). Conclusions: OS-12 was 73%, meeting the primary endpoint and suggesting potential activity of BAV in newly diagnosed GBM. BAV leads to on-target depletion of intratumoral immunosuppressive MDSCs and anti-angiogenic effects. As expected, based on the mechanism of action of BAV, there was no difference in PBMC gene expression profile in patients with long and short survival. Combining BAV with immune checkpoint inhibitors in the future may augment tumor immune response. Clinical trial information: NCT03139916.

TPS2075 Background: Ofranergene obadenovec (ofra-vec, VB-111) is an anti-cancer gene based immune activator and targeted vascular disruptor. The dual mechanism of action triggers a broad antiangiogenic effect and induces of a tumor directed immune response. A previous study demonstrated a survival benefit for patients with recurrent glioblastoma (rGBM) treated with ofra-vec monotherapy, that was continued after progression in combination with bevacizumab. Glioblastoma is an immunologically “cold” microenvironment which fosters immunosuppression and antagonizes anti-tumor immune responses. The role of T-cell infiltration in combating cancer has been increasingly recognized and associated with improved participant outcomes. Based on these observations, this study will assess the hypothesis that neoadjuvant use of ofra-vec will lead to a statistically significant increase in tumor infiltrating T lymphocyte (TIL) density within the tumor and enhanced systemic tumor-specific T cell responses. Methods: Study NCT04406272 is a multicenter, randomized, blinded, placebo-controlled, phase 2 surgical trial to evaluate early immunologic pharmacodynamic parameters for the viral cancer therapy ofra-vec in rGBM. 45 participants with rGBM indicated for resection will randomized to one of three treatment arms: Neoadjuvant Arm: intravenous ofra-vec prior to resection, and ofra-vec every 6 weeks after resection. Adjuvant Arm: placebo prior to resection, and ofra-vec every 6 weeks afterwards. The control arm will receive placebo prior to resection followed by standard of care. Upon evidence of contrast-enhancing progression, bevacizumab may be initiated as needed for supportive care; however, ofra-vec will continue until progression is supported at two consecutive time points. Tumor samples will be obtained and archived at the time of surgery, and blood samples will be obtained as pharmacodynamic markers throughout the study to allow DNA sequencing of T cells. The primary endpoint is to evaluate the influence of neoadjuvant ofra-vec on TIL density. Other endpoints include safety and tolerability, peripheral T cell response, 6mPFS and OS. Study is open for enrolment. Clinical trial information: NCT04406272.

Background: The Neurologic Assessment in Neuro-Oncology (NANO) scale, a standardized metric to objectively measure neurologic function in adult brain tumor patients, complements radiographic assessment in evaluating outcomes of neuro-oncology patients in clinical trials and clinical practice. Currently, there is no standardized measure for neurologic function in pediatric neuro-oncology patients despite their distinct clinical presentations and tumor locations. Therefore, we developed a dedicated pediatric NANO (pNANO) scale. Methods: An international group of pediatric neurologists and adult and pediatric neuro-oncologists convened bi-weekly over 5 months to draft the pNANO scale as an objective and quantifiable measure of neurologic function in children that can be administered during routine examination by pediatric-trained providers of any sub-specialty and be utilized together with other indicators to assess response in clinical trials. Results: Ten relevant domains of neurologic function were identified based on common pediatric brain tumor locations: gait, strength, cerebellar function, visual fields, visual acuity, facial strength, level of consciousness, extraocular movements, dysarthria and dysphagia. For each domain, developmental age appropriate levels of function were defined and categorized. Each domain, based on direct observation and testing during any routine neurological exam, can be used for longitudinal monitoring. Conclusions: The pNANO scale has been developed and aims to provide an objective metric of neurologic function for pediatric brain tumor patients. This scale will be tested for reliability, feasibility and inter-observer variability. Consistent evaluation of neurologic function using pNANO along with radiographic assessment will enable more comprehensive and standardized response assessment in pediatric neuro-oncology patients enrolled in clinical trials.

2020 Background: The Response Assessment in Neuro-Oncology (RANO) and modified RANO (mRANO) criteria are the two most widely used criteria to evaluate treatment response in glioblastoma (GBM) clinical trials. Unlike RANO, mRANO omits the evaluation of FLAIR sequence and requires a repeat scan to confirm responses. It also uses the post-radiation (RT) MRI as a baseline MRI in the newly diagnosed setting instead of the pre-RT MRI used in RANO. We sought to compare the 2 response assessment criteria and evaluate the differences between them in a large patient population. We also sought to compare them to immunotherapy RANO (iRANO) in patients who received immunotherapy. Methods: We conducted a retrospective review of consecutive patients with newly diagnosed (nGBM) and recurrent (rGBM) IDH wild-type GBM treated at Dana-Farber Cancer Institute from 2014 to 2020. Bidimensional measurements of enhancing disease and evaluation of FLAIR sequences were performed by two independent readers on patients’ brain MRIs obtained before change of treatment, and discrepancies were evaluated by a third reader. Dates of disease progression (PD) were identified using RANO, mRANO, iRANO, and other response assessment criteria variations. Spearman’s correlations between PFS and OS were calculated using an iterative multiple imputation method to account for any right-censoring. Results: 526 and 580 patients were included in the newly diagnosed and recurrent cohorts, respectively. Spearman’s correlations were not significantly different between RANO and mRANO in the nGBM (0.69 [95% CI 0.62 to 0.75] vs. 0.67 [0.60, 0.73]) and rGBM (0.45 [0.37, 0.52] vs. 0.50 [0.42, 0.57]) cohorts. Evaluation of FLAIR sequences did not improve the correlation between PFS and OS in patients who received antiangiogenic therapy. Addition of confirmation scans was associated with stronger Spearman’s correlations only when PD was identified within 12 weeks of completion of RT in the nGBM cohort, but did not affect the Spearman’s correlations in the rGBM cohort. The use of the post-RT MRI as a baseline was associated with a higher Spearman’s correlation in nGBM than the use of pre-RT MRI (0.67 [0.60, 0.73] vs. 0.53 [0.42, 0.62]). Among 98 patients with nGBM and 175 patients with rGBM who received immunotherapy, the Spearman’s correlations (nGBM and rGBM) with iRANO (0.63 [0.44, 0.76] and 0.34 [0.17, 0.49]) were similar to RANO (0.73 [0.60, 0.82] and 0.42 [0.28, 0.54]) and mRANO (0.65 [0.48, 0.77] and 0.43 [0.28, 0.56]). Conclusions: RANO and mRANO demonstrated similar correlation between PFS and OS. The evaluation of FLAIR can be omitted, while confirmation scans appear to be only beneficial in the nGBM settings during the first 12 weeks of completion of RT. There was a nonsignificant trend in favor of the use of post-RT MRI as the baseline scan in the nGBM setting. The application of iRANO criteria did not add significant benefit in patients who received immunotherapy.

Brain metastases affect a significant percentage of patients with advanced extracranial malignancies. Yet, the incidence of brain metastases remains poorly described, largely due to limitations of population-based registries, a lack of mandated reporting of brain metastases to federal agencies, and historical difficulties with delineation of metastatic involvement of individual organs using claims data. However, in 2016, the Surveillance Epidemiology and End Results (SEER) program released data relating to the presence vs absence of brain metastases at diagnosis of oncologic disease. In 2020, studies demonstrating the viability of utilizing claims data for identifying the presence of brain metastases, date of diagnosis of intracranial involvement, and initial treatment approach for brain metastases were published, facilitating epidemiologic investigations of brain metastases on a population-based level. Accordingly, in this review, we discuss the incidence, clinical presentation, prognosis, and management patterns of patients with brain metastases. Leptomeningeal disease is also discussed. Considerations regarding individual tumor types that commonly metastasize to the brain are provided.

On July 24, 2020, a workshop sponsored by the National Brain Tumor Society was held on innovating brain tumor clinical trials based on lessons learned from the COVID-19 experience. Various stakeholders from the brain tumor community participated including the US Food and Drug Administration (FDA), academic and community clinicians, researchers, industry, clinical research organizations, patients and patient advocates, and representatives from the Society for Neuro-Oncology and the National Cancer Institute. This report summarizes the workshop and proposes ways to incorporate lessons learned from COVID-19 to brain tumor clinical trials including the increased use of telemedicine and decentralized trial models as opportunities for practical innovation with potential long-term impact on clinical trial design and implementation.

Tumoral hypoxia correlates with worse outcomes in glioblastoma (GBM). While bevacizumab is routinely used to treat recurrent GBM, it may exacerbate hypoxia. Evofosfamide is a hypoxia-targeting prodrug being tested for recurrent GBM. To characterize resistance to bevacizumab and identify those with recurrent GBM who may benefit from evofosfamide, we ascertained MRI features and hypoxia in patients with GBM progression receiving both agents. Thirty-three patients with recurrent GBM refractory to bevacizumab were enrolled. Patients underwent MR and 18F-FMISO PET imaging at baseline and 28 days. Tumor volumes were determined, MRI and 18F-FMISO PET-derived parameters calculated, and Spearman correlations between parameters assessed. Progression-free survival decreased significantly with hypoxic volume [hazard ratio (HR) = 1.67, 95% confidence interval (CI) 1.14 to 2.46, P = 0.009] and increased significantly with time to the maximum value of the residue (Tmax) (HR = 0.54, 95% CI 0.34 to 0.88, P = 0.01). Overall survival decreased significantly with hypoxic volume (HR = 1.71, 95% CI 1.12 to 12.61, p = 0.01), standardized relative cerebral blood volume (srCBV) (HR = 1.61, 95% CI 1.09 to 2.38, p = 0.02), and increased significantly with Tmax (HR = 0.31, 95% CI 0.15 to 0.62, p s = 0.77, P s = 0.75, P

Cancer immunotherapy has made remarkable advances with over 50 separate Food and Drug Administration (FDA) approvals as first- or second-line indications since 2015. These include immune checkpoint blocking antibodies, chimeric antigen receptor-transduced T cells, and bispecific T-cell–engaging antibodies. While multiple cancer types now benefit from these immunotherapies, notable exceptions thus far include brain tumors, such as glioblastoma. As such, it seems critical to gain a better understanding of unique mechanistic challenges underlying the resistance of malignant gliomas to immunotherapy, as well as to acquire insights into the development of future strategies. An Immuno-Oncology Think Tank Meeting was held during the 2019 Annual Society for Neuro-Oncology Scientific Conference. Discussants in the fields of neuro-oncology, neurosurgery, neuro-imaging, medical oncology, and cancer immunology participated in the meeting. Sessions focused on topics such as the tumor microenvironment, myeloid cells, T-cell dysfunction, cellular engineering, and translational aspects that are critical and unique challenges inherent with primary brain tumors. In this review, we summarize the discussions and the key messages from the meeting, which may potentially serve as a basis for advancing the field of immune neuro-oncology in a collaborative manner.

BACKGROUND Glioblastoma (GBM) is the most common and aggressive primary brain tumor with median overall survival of 15 months and 5-7 months for patients with newly diagnosed or recurrent disease (nGBM or rGBM), respectively. Selinexor is a first-in-class, oral, selective inhibitor of nuclear export which blocks exportin 1 (XPO1), forcing the nuclear retention and reactivation of tumor suppressor proteins, ultimately causing cancer cell death. Increased XPO1 expression in gliomas is associated with higher pathological grade and poorer prognosis. Consistent with these data, selinexor inhibited tumor growth and prolonged survival in an animal model of GBM. Importantly, selinexor showed encouraging intra-tumoral penetration and single-agent efficacy in rGBM (KING study). The current trial tests the hypothesis that adding selinexor to standard therapy will improve clinical outcomes for patients with nGBM or rGBM. METHODS To facilitate the successful development of new therapies, consensus recommendations are to use biomarker enrichment and flexible design that allows expansion of promising cohorts. Accordingly, this phase 1a dose finding study is followed by a phase 1b dose expansion (and ultimately by a 1:1 randomized phase 2 efficacy exploration trial) to independently evaluate: radiation + selinexor in nGBM with unmethylated MGMT promoter (Arm A), radiation + temozolomide + selinexor for nGBM with methylated MGMT promoter (Arm B), and lomustine + selinexor in rGBM (Arm C). Bevacizumab or TTField + selinexor in rGBM (Arms D & E, respectively) are being considered. The Phase 1a primary endpoint is maximum tolerated dose/recommended phase 2 dose. The phase 1b primary endpoint is PFS at 3 months against historic controls. The phase 1b dose expansion is included to evaluate preliminary efficacy before launching into a randomized phase 2 trial. Patient quality of life during the trial will be objectively measured using digital devices (e.g. smartwatch/customized smartphone app). We are currently enrolling patients nationwide. Clinical Trial Registration number: NCT04421378.

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.

BACKGROUND The Individualized Screening Trial of Innovative Glioblastoma Therapy (INSIGhT) is a phase II platform trial with Bayesian adaptive randomization and deep genomic profiling to more efficiently test experimental agents in newly diagnosed glioblastoma and to prioritize therapies for late-stage testing. METHODS In the ongoing INSIGhT trial, patients with newly diagnosed MGMT-unmethylated glioblastoma are randomized to the control arm or one of three experimental therapy arms (CC-115, abemaciclib, and neratinib). The control arm therapy is radiotherapy with concomitant and adjuvant temozolomide, and primary endpoint is overall survival. Randomization has been adapted based on Bayesian estimation of biomarker-specific probability of treatment impact on progression-free survival (PFS). All tumors undergo detailed molecular sequencing, and this is facilitated with the companion ALLELE protocol. To evaluate feasibility of this approach, we assessed the status of this ongoing trial. RESULTS Since INSIGhT was activated 4.3 years ago, it has expanded to include 12 sites across the United States. A total of 247 patients have been enrolled. Randomization probabilities have been repeatedly adjusted over time based upon early PFS results to alter the randomization ratio from standard 1:1:1:1 randomization. All three arms have completed accrual and efficacy estimates are available based upon comparison to the common control arm in context of relevant biomarkers. There are 87 patients alive and in follow-up, and there are ongoing plans to add additional arms to evaluate further treatments in the future. CONCLUSION The INSIGhT trial demonstrates that a multi-center Bayesian adaptive platform trial is a feasible and effective approach to help prioritize therapies and biomarkers for newly diagnosed GBM. The trial has maintained robust accrual, and the simultaneous testing of multiple agents, sharing a common control arm and adaptive randomization serve as features to increase trial efficiency relative to traditional clinical trial designs.

PURPOSE/OBJECTIVE(S) While glioblastoma (GBM) is known to have increased incidence in males, recent work has identified possible sex-specific molecular differences that could be associated with improved clinical outcomes for female GBM patients. We evaluated sex-based differences in patient and tumor characteristics, and clinical outcomes in newly diagnosed GBM patients. MATERIALS/METHODS We reviewed 665 newly diagnosed adult IDH-wild type GBM patients with Karnofsky Performance Status (KPS) ≥60 who were treated at our institution from January 1, 2010 to May 30, 2019. Patient, tumor and treatment details were obtained from the electronic medical record. An unpaired t-test, Fisher's exact test and univariable/multivariable Cox proportional hazards modeling were used to evaluate associations, including progression free survival (PFS) and overall survival (OS). RESULTS In our GBM cohort, 384 (57.7%) were male and 281 (42.3%) were female. There were no significant differences in age (60.6 years in males vs. 60.0 years in females, P = 0.16), KPS (KPS ≥90 in 46.1% in males vs. 43.4% in females, P = 0.53), extent of resection (gross total resection in 44.8% in males vs. 47.7% in females, P = 0.48), or prevalence of MGMT methylation (37.8% in males vs. 43.4% in females, P = 0.11). There were also no differences in receipt of temozolomide (95.1% of males vs. 95.7% of females, P = 0.71), radiation dose (≥59.4 Gy in 85.2% in males vs. 87.5% in females, P = 0.43), or clinical trial enrollment (24.7% males vs. 21.0% females, P = 0.27). Median OS was 22.5 months for females and 19.3 months for males (hazard ratio [HR] 0.81, 95% CI 1.03-1.48, P = 0.02). On multivariable analysis adjusted for age (adjusted hazard ratio [AHR] 1.04, 95% CI [1.03-1.05], P < 0.001), KPS ≥90 (AHR 0.73, 95% CI [0.60-0.89], P = 0.002), extent of resection (AHR 1.12, 95% CI 0.92-1.37, P = 0.26), and MGMT methylation status (AHR 0.38, 95% CI [0.31-0.47], P < 0.001), female sex (AHR 0.78, 95% CI [0.64-0.95], P = 0.015) was associated with improved OS. Superior OS in females was observed in MGMT unmethylated patients (HR 0.69, 95% CI [0.54-0.90], P = 0.005) but not in MGMT methylated patients (HR 0.85, 95% CI [0.64-1.14], P = 0.28). While age (AHR 1.02, 95% CI [1.02-1.03], P < 0.001), KPS ≥90 (AHR 0.79, 95% CI [0.66-0.95], P = 0.01), and MGMT methylation (AHR 0.40, 95% CI [0.33-0.49], P < 0.001) were associated with PFS, biologic sex was not associated with PFS (AHR 0.94, 95% CI [0.78-1.12], P = 0.49). CONCLUSION Female sex was associated with improved survival after adjustment of known clinical covariates in newly diagnosed GBM patients. Further study is necessary to understand biologic mechanism for sex-based differences in clinical outcome given implications for therapy development and clinical trial design. AUTHOR DISCLOSURE D.D. Shi: None. M. Lim-Fat: None. G.C. Youssef: None. S. Whorral: None. M. Allen: None. D.N. Cagney: None. S. Tanguturi: None. D. Haas-Kogan: Research Grant; Novartis; Cellworks. A.A. Aizer: Research Grant; Varian. Consultant; Novartis. Advisory Board; Seattle Genetics. J. McFaline-Figueroa: None. U.N. Chukwueke: None. E.Q. Lee: None. D.A. Reardon: Research Grant; Celldex, Inovio, Midatech. Consultant; Amgen. Speaker's Bureau; Merck/Schering, Roche/Genentech. Advisory Board; AbbVie, Bristol Myers Squibb, Cavion, Celldex, EMD Serono, Juno Pharmaceuticals, Momenta Pharmaceuticals, Novartis, Novocure, Oxigene, Regeneron, Roche/Genentech, Stemline. L. Nayak: None. W.L. Bi: Research Grant; The Leukemia and Lymphoma Society, NIH/NCI.R. Beroukhim: Independent Contractor; Scorpion Therapeutics. Stock; Scorpion Therapeutics. K.L. Ligon: None. B.M. Alexander: Research Grant; Puma Biotechnology, Eli Lily, Celgene. Stock; Hoffman-La Roche. P.Y. Wen: None. R. Rahman: Research Grant; Project Data Sphere, LLC.

Summary Functional precision medicine aims to match individual cancer patients to optimal treatment through ex vivo drug susceptibility testing on patient-derived cells. However, few functional diagnostic assays have been validated against patient outcomes at scale because of limitations of such assays. Here, we describe a high-throughput assay that detects subtle changes in the mass of individual drug-treated cancer cells as a surrogate biomarker for patient treatment response. To validate this approach, we determined ex vivo response to temozolomide in a retrospective cohort of 69 glioblastoma patient-derived neurosphere models with matched patient survival and genomics. Temozolomide-induced changes in cell mass distributions predict patient overall survival similarly to O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation and may aid in predictions in gliomas with mismatch-repair variants of unknown significance, where MGMT is not predictive. Our findings suggest cell mass is a promising functional biomarker for cancers and drugs that lack genomic biomarkers.

PURPOSE: Although uncommon, detection of BRAF V600E mutations in adult patients with glioblastoma has become increasingly relevant given the widespread application of molecular diagnostics and encouraging therapeutic activity of BRAF/MEK inhibitors. METHODS: We performed a retrospective study of adult glioblastoma patients treated at Dana-Farber Cancer Institute/Brigham and Women’s Hospital or Massachusetts General Hospital from January 2011 to July 2019 with an identified BRAF V600E mutation by either immunohistochemistry or molecular testing. Patient characteristics, molecular genomics, and preoperative MRI were analyzed. RESULTS: Nineteen glioblastoma patients were included, with median age at diagnosis of 41-years-old (range 22–69). Only 1/18 was IDH1/2-mutant; 10/17 had MGMT unmethylated tumors. The most common additional molecular alterations were CDKN2A/2B biallelic loss/loss-of-function (10/13, 76.9%), polysomy 7 (8/12, 66.7%), monosomy 10 (5/12, 41.7%), PTEN biallelic loss/loss-of-function (5/13, 38.5%) and TERT promoter mutations (5/15, 33.3%). Most tumors were well-circumscribed (11/14) and all were contrast-enhancing on MRI. Twelve patients eventually developed subependymal or leptomeningeal dissemination. Six patients were treated with BRAF/MEK inhibition following disease progression after standard of care therapy, with 4/6 patients showing partial response or stable disease as best response. Median time to progression after BRAF/MEK inhibition was 6.0 months (95% CI 1.2–11.8). Grade 1 skin rash was present in 2 patients, but no other adverse events were reported. Median OS for the entire cohort was 24.1 months (95% CI 15.7–38.9). CONCLUSION: Understanding the natural history and features of BRAF V600E glioblastoma may help better identify patients for BRAF/MEK inhibition and select therapeutic strategies.