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Vorasidenib and ivosidenib inhibit mutant forms of isocitrate dehydrogenase (mIDH) and have shown preliminary clinical activity against mIDH glioma. We evaluated both agents in a perioperative phase 1 trial to explore the mechanism of action in recurrent low-grade glioma (IGG) and select a molecule for phase 3 testing. Primary end-point was concentration of D-2-hydroxyglutarate (2-HG), the metabolic product of mIDH enzymes, measured in tumor tissue from 49 patients with mIDH1-R132H nonenhancing gliomas following randomized treatment with vorasidenib (50 mg or 10 mg once daily, q.d.), ivosidenib (500 mg q.d. or 250 mg twice daily) or no treatment before surgery. Tumor 2-HG concentrations were reduced by 92.6% (95% credible interval (CrI), 76.1-97.6) and 91.1% (95% CrI, 72.0-97.0) in patients treated with vorasidenib 50 mg q.d. and ivosidenib 500 mg q.d., respectively. Both agents were well tolerated and follow-up is ongoing. In exploratory analyses, 2-HG reduction was associated with increased DNA 5-hydroxymethylcytosine, reversal of 'proneural' and 'stemness' gene expression signatures, decreased tumor cell proliferation and immune cell activation. Vorasidenib, which showed brain penetrance and more consistent 2-HG suppression than ivosidenib, was advanced to phase 3 testing in patients with mIDH LGGs. Funded by Agios Pharmaceuticals, Inc. and Servier Pharmaceuticals LLC; ClinicalTrials.gov number NCT03343197.

Background Medulloblastoma (MB) is a rare central nervous system malignancy of adults, with limited contemporary studies to define treatment guidelines and expected late toxicity. Methods A single-center, retrospective study was conducted of patients age ≥18 years from 1997–2019 with MB and who were treated with postoperative radiotherapy. Late toxicity was defined as a minimum of 18 months from diagnosis. Overall survival (OS) and progression-free survival (PFS) were characterized using Kaplan-Meier and Cox regression analyses. Results Fifty-nine patients met criteria, with median age of 25 years (range 18–62 y) and median follow-up of 6.5 years (range 0.7–23.1 y). At diagnosis, 68% were standard-risk, 88% Chang M0, and 22% with anaplastic histology. Gross total resection was achieved in 75%; median craniospinal irradiation dose was 30.6 Gy (relative biological effectiveness [RBE]), median total dose was 54.0 Gy (RBE), 80% received proton radiotherapy; 81% received chemotherapy. 5 year PFS and OS were 86.5% and 95.8%, respectively; 10 year PFS and OS were 83.9% and 90.7%, respectively. Anaplastic histology was associated with worse PFS (P = .04). Among eight recurrences, 25% presented after 5 years. Most common grade ≥2 late toxicities were anxiety/depressive symptoms (30%), motor dysfunction (25%), and ototoxicity (22%). Higher posterior fossa radiation dose was associated with increased risk of late toxicity, including worse cognitive dysfunction (P = .05). Conclusions Adults with MB have favorable survival outcomes, but late failures and toxicity are not uncommon. Better understanding of prognostic factors, possibly from molecular subtyping, may help to define more personalized treatments for patients with high risk of recurrence and long-term treatment sequelae.

We define cancer equity as all people having as the same opportunity for cancer prevention, treatment, and survivorship care. However, marginalized populations continue to experience avoidable and unjust disparities in cancer care, access to clinical trials, and cancer survival. Racial and ethnic minorities, and individuals with low socioeconomic status, Medicaid insurance, limited health literacy, disabilities, and mental health disorders are more likely to experience delays to cancer diagnosis and less likely to receive guideline-concordant cancer care. These disparities are impacted by the social determinants of health including structural discrimination, racism, poverty, and inequities in access to healthcare and clinical trials. There is an urgent need to develop and adapt evidence-based interventions in collaboration with community partners that have potential to address the social determinants of health and build capacity for cancer care for underserved populations. We established the Virtual Equity Hub by developing a collaborative network connecting a comprehensive cancer center, academic safety net hospital, and community health centers and affiliates. The Virtual Equity Hub utilizes a virtual tumor board, an evidence-based approach that increases access to multi-specialty cancer care and oncology subspecialty expertise. We adapted the tumor board model by engaging person-centered teams of multi-disciplinary specialists across health systems, addressing the social determinants of health, and applying community-based research principles with a focus on populations with poor cancer survival. The virtual tumor board included monthly videoconferences, case discussion, sharing of expertise, and a focus on addressing barriers to care and trial participation. Specifically, we piloted virtual tumor boards for breast oncology, neuro-oncology, and individuals with cancer and serious mental illness. The Virtual Equity Hub demonstrated promise at building capacity for clinicians to care for patients with complex needs and addressing barriers to care. Research is needed to measure the impact, reach, and sustainability of virtual equity models for patients with cancer.

Figure S3

Purpose:Dopamine receptor D2 (DRD2) is a G protein–coupled receptor antagonized by ONC201, an anticancer small molecule in clinical trials for high-grade gliomas and other malignancies. DRD5 is a dopamine receptor family member that opposes DRD2 signaling. We investigated the expression of these dopamine receptors in cancer and their influence on tumor cell sensitivity to ONC201.Experimental Design:The Cancer Genome Atlas was used to determine DRD2/DRD5 expression broadly across human cancers. Cell viability assays were performed with ONC201 in >1,000 Genomic of Drug Sensitivity in Cancer and NCI60 cell lines. IHC staining of DRD2/DRD5 was performed on tissue microarrays and archival tumor tissues of glioblastoma patients treated with ONC201. Whole exome sequencing was performed in RKO cells with and without acquired ONC201 resistance. Wild-type and mutant DRD5 constructs were generated for overexpression studies.Results:DRD2 overexpression broadly occurs across tumor types and is associated with a poor prognosis. Whole exome sequencing of cancer cells with acquired resistance to ONC201 revealed a de novo Q366R mutation in the DRD5 gene. Expression of Q366R DRD5 was sufficient to induce tumor cell apoptosis, consistent with a gain-of-function. DRD5 overexpression in glioblastoma cells enhanced DRD2/DRD5 heterodimers and DRD5 expression was inversely correlated with innate tumor cell sensitivity to ONC201. Investigation of archival tumor samples from patients with recurrent glioblastoma treated with ONC201 revealed that low DRD5 expression was associated with relatively superior clinical outcomes.Conclusions:These results implicate DRD5 as a negative regulator of DRD2 signaling and tumor sensitivity to ONC201 DRD2 antagonism.

Table S1

Supplementary legends for Figures S1-S5 and Tables S1-S2.

BACKGROUND: Patients with recurrent glioblastoma (GBM) are often treated with antiangiogenic agents, such as bevacizumab (BEV). Despite therapeutic promise, conventional MRI methods fail to help determine which patients may not benefit from this treatment. PURPOSE: To use MR spectroscopic imaging (MRSI) with intermediate and short echo time to measure corrected myo-inositol (mI)normalized by contralateral creatine (hereafter, mI/c-Cr) in participants with recurrent GBM treated with BEV and to investigate whether such measurements can help predict survivorship before BEV initiation (baseline) and at 1 day, 4 weeks, and 8 weeks thereafter. MATERIALS AND METHODS: In this prospective longitudinal study (2016–2020), spectroscopic data on mI—a glial marker and osmoregulator within the brain—normalized by contralateral creatine in the intratumoral, contralateral, and peritumoral volumes of patients with recurrent GBM were evaluated. Area under the receiver operating characteristic curve (AUC) was calculated for all volumes at baseline and 1 day, 4 weeks, and 8 weeks after treatment to determine the ability of mI/c-Cr to help predict survivorship. RESULTS: Twenty-one participants (median age ± standard deviation, 62 years ± 12; 15 men) were evaluated. Lower mI/c-Cr in the tumor before and during BEV treatment was predictive of poor survivorship, with receiver operating characteristic analyses showing an AUC of 0.75 at baseline, 0.87 at 1 day after treatment, and 1 at 8 weeks after. A similar result was observed in contralateral normal-appearing tissue and the peritumoral volume, with shorter-term survivors having lower levels of mI/c-Cr. In the contralateral volume, a lower ratio of mI to creatine (hereafter, mI/Cr) predicted shorter-term survival at baseline and all other time points. Within the peritumoral volume, lower mI/c-Cr levels were predictive of shorter-term survival at baseline (AUC, 0.80), at 1 day after treatment (AUC, 0.93), and at 4 weeks after treatment (AUC, 0.68). CONCLUSION: Lower levels of myo-inositol normalized by contralateral creatine within intratumoral, contralateral, and peritumoral volumes were predictive of poor survivorship and antiangiogenic treatment failure as early as before bevacizumab treatment. Adapting MR spectroscopic imaging alongside conventional MRI modalities conveys critical information regarding the biologic characteristics of tumors to help better treat individuals with recurrent glioblastoma. Clinical trial registration no. NCT02843230 © RSNA, 2021 Online supplemental material is available for this article.

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 and current standard of care is RT followed by monitoring. Dordaviprone (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 five open-label trials previously demonstrated efficacy in dordaviprone-treated patients with recurrent disease. This phase 3 trial will be the first randomized, controlled study evaluating dordaviprone in patients with H3 K27M-mutant disease. Methods: ACTION (NCT05580562) is a randomized, double-blind, placebo-controlled, parallel-group, international Phase 3 study of dordaviprone in patients with newly diagnosed H3 K27M-mutant diffuse glioma. Patients who have completed standard frontline radiotherapy will be randomized 1:1:1 to receive placebo, once-weekly dordaviprone, or twice-weekly dordaviprone on two consecutive days. Primary efficacy endpoints are overall survival (OS) and progression-free survival (PFS) in all participants; PFS will be assessed by 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/Lansky 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. ACTION is currently enrolling in the United States, with additional sites to be open internationally in 2023. Citation Format: Isabel Arrillaga-Romany, Andrew Lassman, Susan L. McGovern, Sabine Mueller, Louis B. Nabors, Martin van den Bent, Michael Vogelbaum, Joshua E. Allen, Allen S. Melemed, Rohinton S. Tarapore, Dewen Yang, Patrick Wen, Timothy Cloughsey. ACTION: A randomized phase 3 study of dordaviprone (ONC201) in patients with newly diagnosed H3 K27M-mutant diffuse glioma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 2 (Clinical Trials and Late-Breaking Research); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(8_Suppl):Abstract nr CT060.

Glioblastoma is immunologically “cold”, with little clinical response to single-agent immune-checkpoint inhibitors (ICI). Our previous randomized study of neoadjuvant and adjuvant pembrolizumab versus adjuvant pembrolizumab in recurrent glioblastoma identified a molecular signature for ICI and suggested that neoadjuvant pembrolizumab improved survival (PMID30742122). We extended these original findings with a single-arm expansion cohort of glioblastoma patients at first or second relapse undergoing surgical resection for recurrent disease. Eligibility was identical to the original study. Patients receiving > 4mg dexamethasone, or with prior immunotherapy or anti-angiogenic therapy were excluded. The primary objective was to determine the effect of neoadjuvant pembrolizumab on cell cycle/cancer proliferation genes. Secondary objectives were PFS-6 and OS. Twenty-five patients received neoadjuvant pembrolizumab followed by tumor resection and adjuvant pembrolizumab until progression or unacceptable toxicity. The median age of participants was 60 years and median KPS was 90. Ninety-six percent of tumors were IDH wild-type and 48% were MGMT promoter methylated. Neoadjuvant pembrolizumab continued to induce alterations in the tumor microenvironment (T-cell/IFN upregulation, cell cycle downregulation; molecular responders (MR)), but the proportion of MR in this trial was 36% compared with 70% in the original treatment cohort. Median OS was 6.8 months. There were no CTCAE grade 4-5 AEs attributable to pembrolizumab. Further analysis of prognostic differences between stage 1 and 2 subjects is underway, as are additional immune and genotypic correlates to further define molecular changes induced by pembrolizumab. Anti-PD1 monotherapy triggers an intra-tumoral genetic signature associated with interferon-γ response and suppression of cell cycle/cancer proliferation in recurrent glioblastoma, though does not extend OS. This surgical window-of-opportunity paradigm allows for attribution of molecular effects to single agents. Future work will evaluate the differences in patient population, tumor characteristics, and address additional immune checkpoints and/or signaling pathways that can be targeted to augment the effectiveness of anti-PD1 in glioblastoma.

Patients with H3K27M-mutated diffuse midline glioma (DMG) have no proven effective therapies beyond radiation. ONC201, a DRD2 antagonist and mitochondrial ClpP agonist, has shown promise in this population. Clinical and genetic variables associated with ONC201 response in H3K27M-mutant DMG continue to be investigated. A combined clinical and genetic study evaluated patients with H3K27M-DMG treated with single-agent ONC201 at the established phase 2 dose. Clinical outcomes of patients treated on two recently completed multi-site clinical studies (NCT03416530 and NCT03134131, n = 75) were compared with historical control data from patients with confirmed H3K27M-DMG (n = 391 total, n = 119 recurrent). Patients treated with ONC201 monotherapy following initial radiation, but prior to recurrence, demonstrated a median overall survival (OS) of 25.6 months from diagnosis and recurrent patients demonstrated a median OS of 16.2 months from recurrence, both of these more than doubling historical outcomes. Using a Cox model to correct for age, gender and tumor location, OS of ONC201-treated patients with H3K27M-mutant tumors remained significantly better than non-ONC201-treated historical controls (p = 0.0001). A survival and radiographic analysis based on tumor location, revealed stronger responses in thalamic patients. In patients with thalamic tumors treated after initial radiation (n = 16), median OS was not reached with median follow up of 22.1 months (historical control median OS of 12.5 months, n = 83, p = 0.0001). Significant correlations were found between baseline cerebral blood flow (CBF) on perfusion imaging and OS (Pearson’s r = 0.75, p = 0.003) and between nrCBF and PFS (r = 0.77, p = 0.002). Baseline tumor sequencing from treated patients (n = 20) demonstrates EGFR mutation (n = 3) and high EGFR expression as a marker of resistance and improved response in tumors with MAPK-pathway alterations (n = 5). In conclusion, ONC201 demonstrates unprecedented clinical and radiographic efficacy in H3K27M-mutant DMG with outcomes enriched in patients with thalamic tumors, treatment prior to recurrence, MAPK-pathway alterations, and patients with relatively high CBF.

Isocitrate Dehydrogenase 1/2 (IDH1/2) mutations are diagnostic for Astrocytoma or Oligodendroglioma, IDH-mutant. In these IDH-mutant gliomas, retinoic acid-related gene expression is commonly silenced by DNA hypermethylation. DNA demethylating agents can epigenetically reprogram IDH-mutant cells and reduce proliferation, likely by re-expression of silenced tumor suppressor pathways. We hypothesized that DNA demethylation might restore the retinoic acid pathway and slow tumor growth. This was the rationale for a preclinical evaluation combining the DNA demethylating agent, 5-Azacytidine (5-Aza), and retinoic acid pathway activation with all-trans retinoic acid (atRA) in IDH-mutant glioma.In this study, we evaluated the effect of 5-Aza and atRA combination on cell proliferation, apoptosis, and gene expression in human glioma cells. In addition, the efficacy of this combination was tested in patient-derived xenograft (PDX) bearing the IDH1R132H mutation, utilizing subcutaneous and orthotopic models.5-Aza reduced the DNA methylation profile and increased the gene expression of retinoic acid-related genes. Combination of 5-Aza and atRA reduced cell growth, increased differentiation marker expression, and apoptosis in IDH1R132H glioma cells. Mechanistically, 5-Aza sensitized IDHIR132H glioma cells to atRA via upregulation of the retinoic acid pathway. Importantly, the drug combination reduced significantly the growth rate of subcutaneous tumors, but in an orthotopic mouse model, the combination did not improve survival and 5-Aza alone provided the best survival benefit.Use of DNA demethylating agent in combination with retinoids shows promise, but further optimization and preclinical studies are required for treatment of intracranial IDH-mutant gliomas.

Background Decitabine (DAC) is an FDA-approved DNA methyltransferase (DNMT) inhibitor that is used in the treatment of patients with myelodysplastic syndromes. Previously, we showed that DAC marks antitumor activity against gliomas with isocitrate dehydrogenase 1 (IDH1) mutations. Based on promising preclinical results, a clinical trial has been launched to determine the effect of DAC in IDH-mutant gliomas. The next step is to comprehensively assess the efficacy and potential determinants of response to DAC in malignant gliomas. Methods The expression and activity of telomerase reverse transcriptase (TERT) and DNMT1 were manipulated in patient-derived IDH1-mutant and -wildtype glioma lines, followed by assessment of cell proliferation with DAC treatment alone or in combination with telomerase inhibitors. RNA sequencing, Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment, and correlation analysis were performed. Results IDH1-mutant glioma tumorspheres with hemizygous codeletion of chromosome arms 1p/19q were particularly sensitive to DAC and showed significant inhibition of DNA replication genes. Our transcriptome analysis revealed that DAC induced expression of cyclin-dependent kinase inhibitor 1A/p21 (CDKN1A), along with downregulation of TERT. These molecular changes were also observed following doxorubicin treatment, supporting the importance of DAC-induced DNA damage in contributing to this effect. We demonstrated that knockdown of p21 led to TERT upregulation. Strikingly, TERT overexpression increased DNMT1 levels and DAC sensitivity via a telomerase-independent mechanism. Furthermore, RNA inhibition (RNAi) targeting of DNMT1 abrogated DAC response in TERT-proficient glioma cells. Conclusions DAC downregulates TERT through p21 induction. Our data point to TERT and DNMT1 levels as potential determinants of response to DAC treatment.

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.

SummaryRecent data showed promising signs of objective tumor responses in subsets of patients with low grade glioma treated with inhibitors of mutant IDH (IDHi) (1). However, the molecular and cellular underpinnings of such responses are not known. Here, we profiled 6,039 transcriptomes by single-cell or single-nucleus RNA-sequencing isolated from three IDH-mutant oligodendroglioma patients with clinical response to IDHi. Importantly, the tissues were sampled on-drug, four weeks from treatment initiation and our dataset includes a matched pre- and on-treatment sample pair. We integrate our findings with analysis of 8,241 transcriptomes from seven untreated samples, 134 bulk samples from the TCGA and experimental models.(2,3) We find that IDHi treatment induces a robust differentiation towards glial lineages, accompanied by a depletion of stem-like cells and a reduction of cell proliferation. Our study provides the first evidence in patients of the differentiating potential of IDHi on the cellular hierarchies that drive oligodendrogliomas.

INTRODUCTION High-grade meningiomas are associated with significant neuro-cognitive morbidity and a poor prognosis. Systemic therapies, to date, have demonstrated minimal efficacy. We recently found that high-grade meningiomas harbor an immunosuppressive tumor microenvironment and that programmed cell death-ligand 1 (PD-L1) expression may contribute to the aggressive phenotype of these tumors. Therefore, we conducted a single-arm, open-label phase II trial evaluating efficacy of pembrolizumab, a PD-1 inhibitor, in a cohort of 24 patients with recurrent and progressive grade II and III meningiomas. METHODS The primary endpoint was the rate of progression-free survival at 6 months. The trial distinguished between 6-month PFS (PFS-6) rates of 26% vs. 52%. If at least 10 patients demonstrated a 6-month PFS, among the 24 patients, the agent would be considered worthy of further study. This design has at least 88% power using an exact binomial test with a one-sided significance level of 0.1. RESULTS Between November 2017 to December 2019, twenty-four patients were enrolled. The majority of the patients in our cohort were heavily pre-treated; prior to enrolling to the study, twenty patients underwent more than one surgical resection and twelve patients had received more than one round of radiotherapy. Our study met its primary endpoint and achieved a 6-month progression-free survival rate of 0.50 (90% exact CI: 0.32-0.68) and a median PFS of 8.3 months (90% CI: 4.1-12.9 months). For the twelve patients who achieved the PFS-6 primary endpoint, median PFS from the start of treatment was 17.3 months (90% CI: 9.7 – 24.3 months). Four patients had grade-3 or higher adverse events that were at least possibly treatment-related, including colitis, skin infection, encephalopathy and transaminitis. CONCLUSION Our study achieved its primary endpoint. These results suggest that pembrolizumab exerts promising activity on these tumors and results in prolonged PFS compared to historical controls.

Diffuse midline gliomas driven by lysine27-to-methionine mutations in histone 3 (H3-K27M DMGs) are among the most fatal brain tumors. Molecular studies including single cell RNA-sequencing (scRNA-seq) of pediatric and predominantly pontine H3-K27M DMGs have shown that the H3-K27M oncohistone keeps glioma cells locked in a stem-like oligodendrocyte precursor cell (OPC) state that is capable of self-renewal and tumor-initiation. However, a comprehensive dissection of the cellular architecture of H3-K27M DMGs across different midline regions and age groups is required to better understand the cell-intrinsic and contextual regulation of H3-K27M DMG cell identities. In particular, the more recently described group of adult H3-K27M DMGs remains understudied. Here, we have collected and characterized 45 H3-K27M mutant patient tumors, spanning pontine (n=26), thalamic (n=17), and spinal (n=2) locations. Median age at surgery was 12 (2-68) years, encompassing 21 early childhood (0-10 years), 12 adolescent (11-20 years), and 12 adult (≥ 21 years) tumors. The majority of samples were obtained pre-treatment (n=28), as opposed to post-treatment or at autopsy (n=17). We profiled all 45 tumors by single cell/single nucleus RNA-seq and selected tumors were further characterized by the single cell assay for transposase-accessible chromatin (scATAC-seq). Our integrated analyses highlight the predominance of transcriptionally and epigenetically defined OPC-like tumor cells as the main cell population of H3-K27M DMGs across all age groups and locations. We further identify distinct age- and location-specific OPC-like cell subpopulations. Comparison of pediatric and adult tumors further demonstrates a significant increase of mesenchymal cell states in adult H3-K27M DMGs, which we link to differences in glioma-associated immune cell compartments between age groups. Together, this study sheds light on the effects of age- and region-dependent microenvironments in shaping cellular identities in H3-K27M DMGs.

Patients with recurrent glioblastoma (rGBM) are often started on anti-angiogenic therapy such as bevacizumab. However, determining treatment failure using conventional MRI methods remains challenging. We prospectively collected longitudinal MR spectroscopy data in 33 patients with rGBM and quantified various metabolites including N-acetylaspartate (NAA), Choline (Cho), and Lactate (Lac). After stratifying patients by 9 month survival, we found that longer-term survivors had decreased Lac/NAA and increased NAA/Cho compared to shorter-term survivors. ROC analyses illustrated that intratumoral changes in NAA/Cho were predictive of survival at 1 day (AUC 0.92), 2 weeks (AUC 0.75), 8 weeks (AUC 0.71) and 16 weeks (AUC 0.85) but not 4 weeks (AUC 0.60). Intratumoral changes in Lac/NAA were predictive of survival at all time points tested (AUCs > 0.76 for all time points). At 8 weeks, 90% of patients with increased Lac/NAA from baseline and 88% of patients with decreased NAA/Cho did not survive 9 months. Changes in NAA/Cho and Lac/NAA may serve as early biomarkers of anti-angiogenic treatment failure.

BACKGROUND Recurrent glioblastoma (rGBM) patients are often treated with anti-angiogenic agents such as bevacizumab (BEV). Despite therapeutic promise, conventional MR methods fail to determine which patients may not benefit. PURPOSE: The purpose of this study was to utilize magnetic resonance spectroscopic imaging (MRSI) with intermediate and short echo time to generate corrected Myo-inositol normalized by contralateral creatine (mI/c-Cr) in patients with rGBM treated with BEV and investigate whether it can predict survivorship prior to BEV initiation (baseline) and at 1-day, 4-weeks, and 8-weeks thereafter. METHODS We conducted a prospective, longitudinal study and evaluated spectroscopic data of myo-inositol (mI), a glial marker and osmoregulator within the brain, normalized to contralateral-creatine (mI/c-Cr) in the intratumoral, contralateral normal appearing white matter, and peritumoral volumes of rGBM patients. Area under the ROC curve (AUC) was calculated for all volumes at baseline, 1-day, 4-weeks, and 8-weeks after treatment to determine mI/c-Cr’s ability to predict survivorship. RESULTS 21 participants (62 ± 12 years, 15 men) were evaluated. Lower mI/c-Cr in the tumor prior to and during BEV treatment predicted poor survivorship, with ROC analyses illustrating an AUC of 0.75 at baseline, 0.87 at 1-day, and 1 at 8 weeks. Lower levels of mI/c-Cr were also observed in the contralateral and the peritumoral volumes for shorter-term survivors. In the contralateral volume, lower mI/Cr was predictive of shorter-term survival at baseline and all other timepoints. Within the peritumoral volume, lower mI/c-Cr was predictive of shorter-term survival at baseline (AUC=0.80), 1-day (AUC=0.93), and 4-weeks (AUC=0.68). CONCLUSIONS Lower levels of mI/c-Cr within intratumoral, contralateral, and peritumoral volumes were predictive of poor survivorship and anti-angiogenic treatment failure as early as one month before BEV treatment. Acquiring MRSI alongside conventional MR imaging modalities can convey critical information regarding tumor microenvironment that informs management of patients with rGBM.

Histone 3 lysine27-to-methionine (H3-K27M) mutations most frequently occur in diffuse midline gliomas (DMGs) of the childhood pons but are also increasingly recognized in adults. Their potential heterogeneity at different ages and midline locations is vastly understudied. Here, through dissecting the single-cell transcriptomic, epigenomic and spatial architectures of a comprehensive cohort of patient H3-K27M DMGs, we delineate how age and anatomical location shape glioma cell-intrinsic and -extrinsic features in light of the shared driver mutation. We show that stem-like oligodendroglial precursor-like cells, present across all clinico-anatomical groups, display varying levels of maturation dependent on location. We reveal a previously underappreciated relationship between mesenchymal cancer cell states and age, linked to age-dependent differences in the immune microenvironment. Further, we resolve the spatial organization of H3-K27M DMG cell populations and identify a mitotic oligodendroglial-lineage niche. Collectively, our study provides a powerful framework for rational modeling and therapeutic interventions.

PURPOSE Hypoxia from inhibition of angiogenesis reduces DNA repair capacity. Targeting homologous recombination pathway also has anti-angiogenic effects. To examine the synergistic effects of disrupting DNA repair pathways and angiogenesis in glioblastoma, we combine cediranib (ced), a pan vascular endothelial growth factor (VEGF) receptor inhibitor with olaparib (ola), a poly-ADP ribose polymerase (PARP) inhibitor compared with bevacizumab (bev), a VEGF-A inhibitor alone. To identify potential biomarkers predicting response to treatments, we also perform whole exome sequencing on archival tissues. METHODS Bevacizumab-naïve adult patients with first or second recurrence of glioblastoma after radiation and temozolomide were randomly assigned to cediranib (30mg PO daily)/olaparib (200mg PO twice daily) or bevacizumab (10mg/kg IV every 2 weeks). The primary end point was progression-free survival (PFS) at 6 months. The secondary end points included safety and overall survival (OS). Whole exome sequencing of formalin-fixed paraffin embedded archival tissue from 23 patients was performed. RESULTS We are presenting the final data from this trial. Between December 2017 and November 2018, a total 70 adult patients with recurrent glioblastoma were randomly assigned to receive ced/ola (n = 35) or bev (n = 35). With a data cut off on 5/30/2022, median PFS was 118 days and 92 days in ced/ola and bev groups, respectively (hazard ratio, 1.099, 95% CI 0.6-2, p = 0.76). Median overall survival was 269.5 days and 192 days in ced/ola and bev groups, respectively (hazard ratio, 0.6892, 95% CI 0.39-1.2, p = 0.2). Whole exome sequencing was performed in total 23 patients (24 samples), 14 patients in the ced/ola group and 9 patients in the bev group. CONCLUSION No significant survival benefit was observed in patients with recurrent glioblastoma treated with ced/ola compared to patients treated with bev monotherapy. Potential biomarkers predicting response to treatment identified from the whole exome sequencing on archival tissues will be presented.

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.

Histone 3 lysine27-to-methionine mutant diffuse midline gliomas (H3-K27M DMGs) are among the most lethal brain tumors. Their putative cellular hierarchy has been shown to be driven by self-renewing stem-like cells arrested in an oligodendrocyte precursor-like (OPC-like) state, of which few cells are able to differentiate towards more mature astrocyte (AC)-like and oligodendrocyte (OC)-like cells. However, the spatial organization underlying this tumor cell architecture and its microenvironmental interactions in intact H3-K27M DMG tissues remain unknown. Here, we profiled the single cell transcriptomes of 45 patient H3-K27M DMGs and derived cell population-specific marker gene combinations to characterize the single cell spatial organization of 16 tumors using targeted in situ sequencing. We thereby resolved different malignant and non-malignant cell populations including cycling, OPC-like, AC-like, OC-like, mesenchymal tumor cells, and non-malignant oligodendrocytes, astrocytes, neurons, myeloid cells, T cells, and vascular cells directly in situ. Global neighborhood analyses indicate a higher tendency of cycling OPC-like cells, vascular cells, and neurons to localize within a more restricted homogeneous compartment, whereas AC-like cells, non-malignant astrocytes and myeloid cells tend to intermingle with different cell populations in a more diffuse manner. Among malignant cells, we observed cycling OPC-like and OC-like cells to co-localize within a niche-like structure that is surrounded by more differentiated AC-like cells. We further validated this stem-like niche at the protein level using multiplexed immunofluorescence via the CODEX system. Finally, we characterized relationships between malignant and non-malignant cells, consistently identifying preferred neighborhoods of mesenchymal tumor cells with vascular and myeloid cells. Together, this study resolves the spatial architecture of H3-K27M DMG malignant and non-malignant cells at single cell resolution and identifies a local niche of the oligodendroglial lineage containing the OPC-like cancer stem-like cells, thus providing novel insights into the cancer stem-like compartment in H3-K27M DMGs and suggesting potential avenues for its perturbation.

BACKGROUND H3 K27M-mutant DMG predominantly affects children and young adults; no effective therapy is known. ONC201 is a first-in-class, anti-cancer DRD2 antagonist and ClpP agonist. METHODS Fifty pediatric and adult patients with recurrent H3 K27M DMG who received oral ONC201 monotherapy in clinical trials and expanded access were selected for a planned efficacy analysis. Eligibility criteria included measurable contrast-enhancing disease by RANO-HGG criteria (excluding pontine and spinal cord tumors), KPS/LPS≥60, ≥90 days from prior radiation, and adequate washout from prior anti-cancer therapy. The primary endpoint was overall response rate (ORR) by RANO-HGG criteria. Secondary endpoints included duration of response, time to response, progression-free survival (PFS), overall survival (OS), corticosteroid response rate, performance status response rate, and ORR by RANO-LGG criteria. Radiographic endpoints were assessed by dual-reader blinded independent central review. Data cutoff was May 31, 2021. RESULTS ORR was 20.0% (95%CI, 10.0–33.7) by RANO-HGG criteria. Median duration of response was 11.2 months (95%CI, 3.8–not reached) and median time to response was 8.3 months (range, 1.9–15.9). PFS at 6 months was 35.1% (95%CI, 21.2–49.3). The ORR was 26.0% (95%CI, 14.6–40.3) by RANO-LGG criteria. Fifteen patients (30.0%; 95%CI, 17.9–44.6) achieved an objective response by RANO-HGG and/or RANO-LGG criteria. Of 15 patients receiving ≥4 mg daily dexamethasone at baseline, 7 (46.7%; 95%CI, 21.3–73.4) achieved ≥50% confirmed reduction in dose. Of 34 patients with baseline KPS/LPS CONCLUSIONS ONC201 monotherapy exhibits durable and clinically meaningful efficacy in recurrent H3 K27M-mutant DMG.

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.

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.

A Man with Eye Pain and Decreased Vision A 65-year-old man with Waldenstrom’s macroglobulinemia was evaluated because of an 8-day history of bilateral eye pain and decreased vision. He had decrease...

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.

Background Determining failure to anti-angiogenic therapy in recurrent glioblastoma (GBM) (rGBM) remains a challenge. The purpose of the study was to assess treatment response to bevacizumab-based therapy in patients with rGBM using MR spectroscopy (MRS). Methods We performed longitudinal MRI/MRS in 33 patients with rGBM to investigate whether changes in N-acetylaspartate (NAA)/Choline (Cho) and Lactate (Lac)/NAA from baseline to subsequent time points after treatment can predict early failures to bevacizumab-based therapies. Results After stratifying based on 9-month survival, longer-term survivors had increased NAA/Cho and decreased Lac/NAA levels compared to shorter-term survivors. ROC analyses for intratumoral NAA/Cho correlated with survival at 1 day, 2 weeks, 8 weeks, and 16 weeks. Intratumoral Lac/NAA ROC analyses were predictive of survival at all time points tested. At the 8-week time point, 88% of patients with decreased NAA/Cho did not survive 9 months; furthermore, 90% of individuals with an increased Lac/NAA from baseline did not survive at 9 months. No other metabolic ratios tested significantly predicted survival. Conclusions Changes in metabolic levels of tumoral NAA/Cho and Lac/NAA can serve as early biomarkers for predicting treatment failure to anti-angiogenic therapy as soon as 1 day after bevacizumab-based therapy. The addition of MRS to conventional MR methods can provide better insight into how anti-angiogenic therapy affects tumor microenvironment and predict patient outcomes.

BACKGROUND The cyclin D-CDK4/6-Rb pathway is activated in most glioblastomas. Abemaciclib is a potent CDK4/6 inhibitor with good brain penetration approved for ER/PR/HER2- breast cancer. In order to efficiently evaluate the potential impact of abemaciclib on overall survival (OS) in newly diagnosed glioblastoma and to simultaneously develop information regarding potential genomic biomarker associations, abemaciclib was included as an arm on the Individualized Screening Trial of Innovative Glioblastoma Therapy (INSIGhT) trial. INSIGhT is a phase II platform trial using response adaptive randomization and deep genomic profiling to more efficiently test experimental agents in MGMT unmethylated glioblastoma and potentially accelerate identification of novel therapies for phase III testing. Initial randomization was equal between abemaciclib, control, and two other experimental arms but subsequent randomization was adapted based on efficacy as determined by progression-free survival (PFS). Ineffective arms were discontinued and new arms added by protocol amendment. We report preliminary results for the abemaciclib arm which has completed accrual. METHODS Patients with newly diagnosed MGMT-unmethylated glioblastoma were randomized to receive either radiotherapy with concomitant and adjuvant temozolomide at standard doses or standard radiochemotherapy followed by adjuvant abemaciclib (150–200 mg orally BID) without temozolomide. Treatment continued until progression or development of unacceptable toxicities. The primary endpoint was OS. Association between abemaciclib efficacy and cyclin D-CDK4/6-Rb pathway genomic alterations was also investigated. RESULTS There were 123 patients (50 control; 73 treated with abemaciclib). Abemaciclib was generally well-tolerated with no new toxicity signals identified. PFS was significantly longer (p=0.03, logrank test) with abemaciclib (median 6.31 months 95% CI [5.29, 8.18]) compared to the control arm (5.16 months 95% CI [4.37, 6.28]). 28/50 control and 36/73 abemaciclib patients remain alive. CONCLUSION Preliminary analysis suggests that abemaciclib increases PFS compared to control. Updated toxicity, PFS and survival data and potential genomic biomarker associations will be presented.

BACKGROUND CC-115 is an oral, CNS-penetrant, selective inhibitor of mammalian target of rapamycin kinase (mTOR) and deoxyribonucleic acid-dependent protein kinase (DNA-PK). Both targets are important in glioblastoma; PI3K/Akt/mTOR signaling is hyperactive in most glioblastomas, and DNA-PK is integral to repair of radiotherapy-mediated DNA damage. To investigate CC-115 in newly diagnosed glioblastoma and explore potential genomic biomarker associations, CC-115 was evaluated in the Individualized Screening Trial of Innovative Glioblastoma Therapy (INSIGhT) trial, an adaptive platform trial designed to efficiently test experimental agents. METHODS Adults with newly diagnosed MGMT-unmethylated glioblastoma, with genomic data available, are eligible for this ongoing trial. Patients are adaptively randomized to one of several experimental arms or the control arm: standard radiotherapy with concurrent and adjuvant temozolomide. The primary endpoint is overall survival (OS). Patients randomized to CC-115 (10mg po BID) received it concurrently with radiotherapy and as adjuvant monotherapy. As the first in-human use of CC-115 with radiation, a safety lead-in 3 + 3 design was used. RESULTS Twelve patients were randomized to CC-115; seven patients had possible treatment-related CTCAE grade > 3 toxicity, including four pre-specified dose-limiting toxicities: liver function abnormality (n=1), hyperlipidemia (n=1), lipase elevation (n=1) and cerebral edema (n=1). There was no significant difference in progression-free survival (PFS, median 4.2 months [CC-115] vs. 5.2 months, p=0.9) or OS (median 10.1 months [CC-115] vs. 14.5 months, p=0.9) compared to the 50 patients randomized to the control arm. Based on early PFS results, randomization probability to CC-115 decreased from 25% to < 10% at time of the trial arm closure. CONCLUSION Concurrent and adjuvant CC-115 was associated with toxicity and failed to improve PFS or OS. The INSIGhT trial design allowed for more efficient testing of CC-115, decreasing patients and resources allocated to a therapy that was discontinued due to concerns about toxicity and unfavorable risk-to-benefit ratio.

PURPOSE Despite the high frequency of EGFR genetic alterations in glioblastoma (GBM), EGFR-targeted therapies have not had success in this disease. To improve the likelihood of efficacy, we targeted adult patients with recurrent GBM enriched for EGFR gene amplification, which occurs in approximately half of GBM, with dacomitinib, a second-generation, irreversible epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor that penetrates the blood-brain barrier, in a multicenter phase II trial. PATIENTS AND METHODS We retrospectively explored whether previously described EGFR extracellular domain (ECD)–sensitizing mutations in the context of EGFR gene amplification could predict response to dacomitinib, and in a predefined subset of patients, we measured post-treatment intratumoral dacomitinib levels to verify tumor penetration. RESULTS We found that dacomitinib effectively penetrates contrast-enhancing GBM tumors. Among all 56 treated patients, 8 (14.3%) had a clinical benefit as defined by a duration of treatment of at least 6 months, of whom 5 (8.9%) remained progression free for at least 1 year. Presence of EGFRvIII or EGFR ECD missense mutation was not associated with clinical benefit. We evaluated the pretreatment transcriptome in circulating extracellular vesicles (EVs) by RNA sequencing in a subset of patients and identified a signature that distinguished patients who had durable benefit versus those with rapid progression. CONCLUSION While dacomitinib was not effective in most patients with EGFR-amplified GBM, a subset experienced a durable, clinically meaningful benefit. Moreover, EGFRvIII and EGFR ECD mutation status in archival tumors did not predict clinical benefit. RNA signatures in circulating EVs may warrant investigation as biomarkers of dacomitinib efficacy in GBM.

BACKGROUND Ivosidenib (AG-120, IVO) is a first-in-class oral inhibitor of mutant isocitrate dehydrogenase 1 (mIDH1), and vorasidenib (AG-881, VOR) is an oral, potent, brain-penetrant inhibitor of mIDH1/2. Both have been evaluated in glioma patients in ongoing phase 1 studies. In orthotopic glioma models, IVO and VOR reduced 2-hydroxyglutarate (2-HG) levels by 85% and 98%, respectively, despite different brain-to-plasma ratios (< 0.04 vs 1.33). METHODS Patients with recurrent, nonenhancing, WHO-2016 grade 2/3, mIDH1-R132H oligodendroglioma or astrocytoma undergoing craniotomy were randomized 2:2:1 to IVO 500mg QD, VOR 50mg QD, or no treatment (cohort 1), or 1:1 to IVO 250mg BID or VOR 10mg QD (cohort 2), for 4 weeks preoperatively. Postoperatively, patients continued receiving IVO or VOR (control patients were randomized 1:1 to IVO or VOR). Tumors were assessed for mIDH1 status, cellularity, and 2-HG and drug concentrations. Treated subjects were compared with controls and mIDH1/wild-type banked reference samples. Primary endpoint: tumor 2-HG concentration following IVO or VOR. RESULTS As of March 1, 2019, 27 patients (18 men; 25/2 grade 2/3) were randomized preoperatively in cohort 1 (IVO 10, VOR 12, untreated 5): 27 received drug (IVO 13, VOR 14); 1 discontinued VOR postoperatively due to disease progression. Of 26 tumors analyzed, 22 were evaluable. Mean brain-to-plasma ratios: 0.13 IVO, 1.59 VOR. Relative to untreated samples, IVO and VOR reduced tumor 2-HG by 92.0% (95% CI 73.2, 97.4) and 92.5% (95% CI 78.1, 97.7), respectively. Common (≥ 4 patients) TEAEs (all cohort 1 patients, all grades): diarrhea (37.0%), constipation, hypocalcemia, and nausea (each 18.5%), anemia, hyperglycemia, pruritus, headache, and fatigue (each 14.8%). Cohort 2 has completed accrual, with analyses ongoing. CONCLUSIONS In cohort 1 of this phase 1 perioperative study, IVO and VOR demonstrated brain penetrance and lowered 2-HG compared with controls. Updated data from both cohorts will be presented.

BACKGROUND Like most proliferating tumors, GBM relies heavily on accurate DNA repair for maintenance of genome stability. Dysfunction in repair of both single and double strand DNA breaks by PARP inhibition and impairment of homologous recombination, respectively, would be synthetically lethal. In this study we combined the PARP inhibitor olaparib with cediranib, a pan VEGF receptor inhibitor. Cediranib may mediate disruption in the homologous recombination pathway through its antiangiogenic properties. METHODS Through the Experimental Therapeutics Clinical Trials Network, we performed an open-label randomized phase II study of bevacizumab (BEV)- naive adult patients with first or second recurrence of glioblastoma after radiation and temozolomide. Patients were randomized 1:1 to receive either olaparib 200 mg by mouth twice daily with cediranib 30 mg by mouth daily or BEV 10 mg/kg IV every 2 weeks. The primary endpoint was progression-free survival at 6 months (PFS6). Secondary endpoints included safety and overall survival. Exploratory objectives included blood, tissue and imaging-based biomarkers of response to treatment. RESULTS Seventy patients were enrolled. Median age was 60.5 years (range: 19–79), 39% females, median KPS was 90 (range: 60–100). Baseline characteristics were well balanced. With a data cut-off of 5/2/2019, PFS6 was 14% [95% CI 4–30%] in the cediranib/olaparib arm vs 30.9% [95% CI 12.7–51.2%] in the BEV arm. Median OS was 247 days in the cediranib/olaparib arm vs 201 days in the BEV arm, HR 0.816, 95% CI (0.431, 1.546). Related grade 3, 4 or 5 toxicity was experienced in 29% vs 12% of patients for the cediranib/olaparib vs BEV arm. CONCLUSION Treatment with cediranib/olaparib failed to increase PFS and OS in patients with recurrent GBM. Blood, tissue and imaging correlates will be presented to help understand why this treatment combination was unsuccessful.

Inhibitors of the mutant isocitrate dehydrogenase 1 (IDH1) entered recently in clinical trials for glioma treatment. Mutant IDH1 produces high levels of 2-hydroxyglurate (2HG), thought to initiate oncogenesis through epigenetic modifications of gene expression. In this study, we show the initial evidence of the pharmacodynamics of a new mutant IDH1 inhibitor in glioma patients, using non-invasive 3D MR spectroscopic imaging of 2HG. Our results from a Phase 1 clinical trial indicate a rapid decrease of 2HG levels by 70% (CI 13%, P = 0.019) after 1 week of treatment. Importantly, inhibition of mutant IDH1 may lead to the reprogramming of tumor metabolism, suggested by simultaneous changes in glutathione, glutamine, glutamate, and lactate. An inverse correlation between metabolic changes and diffusion MRI indicates an effect on the tumor-cell density. We demonstrate a feasible radiopharmacodynamics approach to support the rapid clinical translation of rationally designed drugs targeting IDH1/2 mutations for personalized and precision medicine of glioma patients., Inhibitors of mutant isocitrate dehydrogenase 1 (IDH1) entered recently clinical trials for treatment of gliomas. Here, the authors apply a MRS imaging method for 2HG detection and assessement of the pharmacodynamic effects of the mutant IDH1 inhibitor (IDH305) in 8 mutant IDH1 glioma patients.

BACKGROUND EGFR is amplified in over 50% of glioblastoma and 20-30% have EGFRvIII mutations. Neratinib is a potent inhibitor of EGFR/HER2 approved for metastatic HER2+ breast cancer. To efficiently evaluate the potential impact of neratinib on overall survival (OS) in newly-diagnosed glioblastoma and to simultaneously develop information regarding potential genomic biomarker associations, neratinib was included as an arm on the Individualized Screening Trial of Innovative Glioblastoma Therapy (INSIGhT) trial. INSIGhT is a phase II platform trial using response adaptive randomization and deep genomic profiling to more efficiently test experimental agents in MGMT unmethylated glioblastoma and accelerate identification of novel therapies for phase III testing. Initial randomization was equal between neratinib, control, and two other experimental arms but subsequent randomization was adapted based on efficacy as determined by progression-free survival (PFS). We report preliminary results for the neratinib arm. METHODS Patients with newly diagnosed MGMT-unmethylated glioblastoma were randomized to receive either radiotherapy with concomitant and adjuvant temozolomide or standard radiochemotherapy followed by adjuvant neratinib (240 mg daily). Treatment continued until progression or development of unacceptable toxicities. The primary endpoint was OS. Association between neratinib efficacy and EGFR amplification was also investigated. RESULTS There were 144 patients (70 control; 74 neratinib). Neratinib was reasonably well-tolerated with no new toxicity signals identified. PFS was compared (HR 0.84; p=0.38, logrank test – not significant) between the neratinib (median 6.05 months) and control (median 5.82 months) arms. For patients EGFR pathway activation the PFS HR was 0.53 (p-value=0.03 – significant, median PFS: neratinib, 6.21 months, control, 5.26 months). However, there was no significant improvement in OS in EGFR amplified/mutated patients (HR 1.05; p-value 0.87) between neratinib (median 14.2) compared to the control arm (median 14.6). CONCLUSION Neratinib prolonged PFS in the EGFR positive subpopulation but there was no overall PFS benefit, or any OS improvement.

BACKGROUND H3 K27M-mutant diffuse midline glioma is an invariably lethal form of brain cancer that disproportionately affects children and young adults and has no effective treatment following front-line radiation. The initial disease definition in the 2016 WHO Classification of Tumors of the Central Nervous System regarded the H3 K27M mutation as pathognomonic, though the definition was updated in 2018 restricting the diagnosis to histologically diffuse gliomas that involve midline CNS structures (cIMPACT-NOW update 2). ONC201 is an investigational anti- cancer small molecule, DRD2 antagonist and ClpP agonist that has induced durable tumor regressions by RANO-HGG criteria in a registration cohort of recurrent diffuse midline glioma, H3 K27M-mutant patients treated with single agent ONC201. METHODS We present 7 patients with H3 K27M-mutant diffuse gliomas were enrolled in ONC201 clinical studies, excluded from the registration cohort due to involvement of non-midline CNS structures, all within the cerebral hemispheres (3 frontal, 1 temporal, 1 frontotemporal, 1 parietal, and 1 corona radiata). RESULTS Two of the 7 patients underwent objective responses by RANO-HGG criteria as assessed by investigator, which was associated with clinical benefit that included increased mobility and level of alertness. CONCLUSIONS These results demonstrate that H3 K27M-mutant diffuse gliomas occur outside of midline CNS structures, and suggest that ONC201 has single agent activity in H3 K27M-mutant gliomas irrespective of CNS location.

BACKGROUND Decitabine (DAC)-incorporated DNA binds DNMT1 enzyme and subsequently triggers DNMT1 degradation. Previously, we showed that DAC can mediate the anti-tumor effect in a preclinical model of IDH-mutant gliomas. Here, we further investigate molecular determinants of response to DAC in gliomas. METHODS DAC response was assessed by soft agar anchorage independent growth assays and cell proliferation measurements. Patient-derived IDH-mutant chromosome 1p/19q codeleted (codel) and non-codel glioma lines upon vehicle and DAC treatment were used for RNA sequencing and Gene Set Enrichment Analysis (GSEA). RESULTS We found that DAC treatment is effective in high TERT-expressing gliomas including IDH-mutant and IDH-wildtype glioma lines. In contrast, pharmacological inhibition of TERT reduces DAC response in glioma lines. Interestingly, transcriptomic profiling showed that DAC reduces the expression of TERT, along with increased CDKN1A/p21 expression. We experimentally validated that TERT expression depends on CDKN1A/p21. Furthermore, p53 is required for DAC-mediated CDKN1A/p21 induction. Importantly, DAC-mediated proliferation defects in TERT-proficient glioma cells are abolished by DNMT1 knockdown, indicative of an expected DAC mechanism. CONCLUSIONS DAC could elicit the pronounced anti-tumor response in IDH-mutant codel oligodendroglioma and IDH-wildtype glioblastoma with TERT activating mutations.

Patients with diffuse midline glioma (DMG) harboring H3 K27M mutation rarely survive longer than two years and have no proven therapies following first-line radiation. ONC201, a bitopic DRD2 antagonist and allosteric ClpP agonist, has shown encouraging efficacy in early phase studies in H3 K27M-mutant DMG. In order to define response rates in H3 K27M DMG patients and to clarify the genomic, anatomic and molecular predictors of response, we performed an integrated pre-clinical and clinical analysis of ONC201 treatment. ONC201 was effective in intra-uterine electroporation (IUE)-generated H3 K27M-mutant murine glioma models with excellent CNS penetration and survival benefit. Patients with H3 K27M-mutant DMG treated with ONC201 on active clinical trials (n=50, 27 thalamic, 23 brainstem) showed an overall survival (OS) of 28.1 (range: 5.9–105) months from diagnosis (enrollment by 4/29/19, data cut-off 12/28/19), compared to historical median OS of 12 months. Median OS for non-recurrent patients has not been reached (n=16, median follow-up: 16.8 from diagnosis). For non-recurrent thalamic patients (n=8), median PFS is 20.1 (range: 9.3–27.6) months from diagnosis (median time on drug: 14.5 months). Best response for thalamic patients by RANO: 1 CR, 5 PR, 7 SD, 8 PD, 6 not reported. Decreased H3 K27M cell-free tumor DNA in plasma and CSF at 6 months correlated with long-term response. Baseline tumor gene expression profiling in patients treated with ONC201 (n=14) identified EGFR and the cortical developmental transcription factor FOXG1 as the strongest biomarkers of radiographic response to ONC201. Analysis of 541 ONC201-treated human cancer cell lines from DepMap, provided evidence for an EGFR-dependent ONC201 resistance mechanism. Analysis of 38 glioma cell lines further supports FOXG1 as a glioma-specific predictive biomarker of ONC201 response. The unprecedented survival results and radiographic responses to ONC201 in H3K27M DMG make a compelling case for later phase and combinatorial studies.

H3 K27M-mutant diffuse midline gliomas (DMG) have a dismal prognosis. We report an integrated analysis for ONC201, a DRD2 antagonist and ClpP agonist, in patients with recurrent H3 K27M DMG administered as monotherapy in 3 clinical studies (NCT03295396, n=20; NCT02525692, n=6; or expanded access, n=4) by independent, central radiology review among 30 patients. At baseline, patients had measurable contrast-enhancing disease by RANO criteria, KPS>60, and were >90 days from prior radiation. Patients with primary lesions that involved the pons or spinal cord or had evidence of leptomeningeal or cerebrospinal fluid dissemination were excluded. ONC201 was orally administered at 625 mg (scaled by body weight for patients < 18 years old) weekly in 29 patients and every 3 weeks in 1 patient. Median age was 31 years (range 8–70; two patients < 18). There were 16 women and 14 men. Tumors were predominantly thalamic (73%), with other locations including the cerebellum (5%), brainstem (non-pontine) (3%), basal ganglia (3%), and midbrain (3%). Median time from prior radiation was 7.5 months. The most frequent drug-related adverse events were low grade nausea (10%) and fatigue (10%). Nine patients (30%) had >50% regression of T1 contrast enhancement and 11 (36.7%) patients had regression of T2/FLAIR. Objective response rate and progression-free survival by RANO criteria, as well overall survival will be reported. Among 8 patients with sustained radiographic regressions, 6 were tapered off dexamethasone and 4 had improvement in KPS. Five patients (16.7%) remain on treatment with a median of 9.5 months (range 7.3–12). In conclusion, single agent ONC201 is well tolerated and clinically active in recurrent H3 K27M DMG patients.

2014 Background: The cyclin D-CDK4/6-Rb pathway is activated in most glioblastomas. Abemaciclib is a potent CDK4/6 inhibitor with good brain penetration approved for HR+/HER2- breast cancer. In order to efficiently evaluate the potential impact of abemaciclib on overall survival (OS) in newly diagnosed glioblastoma and to simultaneously develop information regarding potential genomic biomarker associations, abemaciclib was included as an arm on the Individualized Screening Trial of Innovative Glioblastoma Therapy (INSIGhT) trial. INSIGhT is a phase II platform trial using response adaptive randomization and deep genomic profiling to more efficiently test experimental agents in MGMT unmethylated glioblastoma and potentially accelerate identification of novel therapies for phase III testing. Initial randomization was equal between abemaciclib, control, and two other experimental arms but subsequent randomization was adapted based on efficacy as determined by progression-free survival (PFS). Ineffective arms were discontinued and new arms added by protocol amendment. We report preliminary results for the abemaciclib arm which has completed accrual. Methods: Patients with newly diagnosed MGMT-unmethylated glioblastoma were randomized to receive either radiotherapy with concomitant and adjuvant temozolomide at standard doses or standard radiochemotherapy followed by adjuvant abemaciclib (150-200 mg orally BID). Treatment continued until progression or development of unacceptable toxicities. The primary endpoint was OS which was assessed using the log-rank test estimated via the Kaplan Meier method using a type I error of 5%. The hazard ratio (HR) was estimated using a cox proportional hazards model. Association between abemaciclib efficacy and cyclin D-CDK4/6-Rb pathway genomic alterations was also investigated. Results: There were 142 patients (69 control; 73 treated with abemaciclib). Abemaciclib was generally well-tolerated with no new toxicity signals identified. PFS was significantly longer (HR 0.67; p = 0.03, logrank test) with abemaciclib (median 6.54 months) compared to the control arm (median 5.88 months). For patients with activation of the CDK4 pathway the PFS HR was 0.64 (p-value = 0.04). However, there was no significant improvement in overall survival (HR 0.9; p-value > 0.05) between abemaciclib (median 15.5) compared to the control arm (median 15.5). Conclusions: Abemaciclib was well-tolerated and prolonged PFS but there is no evidence of an overall survival improvement compared to standard radiochemotherapy. Clinical trial information: NCT02977780.

// Isabel Arrillaga-Romany 1 , Andrew S. Chi 3 , Joshua E. Allen 4 , Wolfgang Oster 4 , Patrick Y. Wen 2 and Tracy T. Batchelor 1 1 Stephen E. and Catherine Pappas Center for Neuro-Oncology, Massachusetts General Hospital, Boston, MA, USA 2 Center for Neuro-Oncology, Dana-Farber/Brigham and Women’s Cancer Center, Boston, MA, USA 3 Laura and Isaac Perlmutter Cancer Center, NYU Langone Medical Center, New York, NY, USA 4 Oncoceutics, Philadelphia, PA, USA Correspondence to: Isabel Arrillaga-Romany, email: // Keywords : ONC201, Imipridone, GPCR, glioblastoma, glioma Received : April 25, 2017 Accepted : April 28, 2017 Published : May 12, 2017 Abstract ONC201 is an oral, small molecule selective antagonist of the G protein-coupled receptor DRD2 that causes p53-independent apoptosis in tumor cells via integrated stress response activation and Akt/ERK inactivation. We performed a Phase II study that enrolled 17 patients with recurrent, bevacizumab-naive, IDH1/2 WT glioblastoma who received 625mg ONC201 every three weeks. Median OS was 41.6 weeks with OS6 of 71% and OS9 of 53%. Seven of 17 patients are alive. PFS6 was 11.8% with two patients remaining on study who continue to receive ONC201 for >12 months. One of these patients had a durable objective response with a secondary glioblastoma possessing a H3.3 K27M mutation, exhibiting regression by 85% in one lesion and 76% in the second lesion. The second patient who continues to receive ONC201 for >12 months remains disease-free after enrolling on this trial following a re-resection. No drug-related SAEs or treatment discontinuation due to toxicity occurred. Plasma PK at 2 hours post-dose was 2.6 ug/mL, serum prolactin induction was observed as a surrogate marker of target engagement, and DRD2 was expressed in all evaluated archival tumor specimens. In summary, ONC201 is well tolerated and may have single agent activity in recurrent glioblastoma patients.

H3 K27M-mutant gliomas often manifest as midline gliomas, have a dismal prognosis, and have no established or effective treatments at recurrence. ONC201 is the first clinical bitopic DRD2 antagonist/ClpP agonist and is under evaluation in Phase II trials for gliomas and other cancers. We previously reported in vitro studies suggesting dysregulated dopamine receptor expression and enhanced ONC201 sensitivity among H3 K27M-mutant gliomas. Following these observations, adults with midline H3 K27M-mutant glioma patients were enrolled to a dedicated Phase II clinical trial (NCT03295396), a multi-arm Phase II trial (NCT0252569), and expanded access protocols under the Sponsor’s IND. An integrated radiographic analysis with an objective response rate primary endpoint in patients who received ONC201 monotherapy with confirmed H3 K27M-mutant glioma (not primarily in the pons or spinal cord and without leptomeningeal spread) that was progressive and measurable disease by RANO criteria, >90 days from completion of prior radiation, and had KPS >60. As of December 15, 2018, 15 patients have received single agent ONC201 who meet these criteria (n=9 NCT03295396; n=5 NCT0252569; n=1 expanded access). ONC201 was orally administered at 625 mg weekly, except for one patient dosed once every 3 weeks. As midline gliomas can exhibit a mixture of contrast-enhancing and non-contrast-enhancing disease, objective response was assessed by blinded independent central review using RANO-HGG and RANO-LGG criteria for each patient. Best response to date by RANO-HGG criteria is at least 27%: 1 CR, 3 PR, 7 SD, and 4 PD; by RANO-LGG is at least 36%: 1 CR, 1 PR, 3 minor response (MR), 4 SD, 5 PD, 1 unevaluable. By RANO-HGG, median onset of response is 2.6 months (range 1.3–3.4); median duration of response has not been reached with a median follow-up of 7.7 months (range 1.8–29.8). Updated radiographic response, pharmacodynamics, safety, and other clinical outcomes will be reported.

BACKGROUND There is no effective therapy for patients (pts) with IDH-mutant gliomas that progress after RT and chemotherapy. At time of progression, these tumors have often transformed to glioblastoma (GBM) and have increased numbers of somatic mutations, i.e. have a “hypermutator phenotype”. We hypothesized that there is synergistic efficacy of Avelumab (anti-PD-L1) combined with HFRT in pts with secondarily transformed IDH-mutant GBMs. Safety-lead-in results will be presented. METHODS This is a phase II, open-label, single-arm, multicenter study of Avelumab with HFRT in adults with transformed IDH-mutant GBM who previously received RT and TMZ and/or PCV. All pts received Avelumab 10 mg/kg IV followed at Day 8 by HFRT (25 Gy in 5 daily 5-Gy fractions) and then Avelumab 10 mg/kg IV every 2 weeks. A 3 + 3 design was used for a 6-patient safety-lead-in cohort. Adverse events were recorded according to CTCAE. RESULTS Six pts (F=4, M=2) with a median age= 45.5 yrs (range 31.5–54.4 yrs) were enrolled in the safety-lead-in cohort. No DLT was observed. Grade ≥ 3 AEs included increased cerebral edema (3 pts), hyponatremia (1 pt) and worsening hemiparesis (3 pts). Grade ≤ 2 AEs included nausea, hypothyroidism, lymphopenia, thrombocytopenia, transaminase elevation, and fever/chills. Median follow-up time was 8.9 mo. Best treatment response was SD in 1 patient. At time of last follow-up all pts have discontinued treatment for PD. Median PFS was 4.2 mo (range 1.4–5.7). Median OS was 10.1 (range 6.8–21+) mo. 4 pts (67%) died, 2 pts remain alive in follow-up at 6.9 and 21.6 months after treatment initiation. The study was closed after the safety lead-in completed enrollment due to slow accrual. CONCLUSIONS Avelumab combined with HFRT was tolerable without dose-limiting toxicity in this safety-lead-in cohort of adult patients with transformed IDH-mutant GBM. Further studies are necessary to determine efficacy of this treatment regimen.

Glioblastoma is the most common primary malignant brain tumor in adults and is associated with poor survival. The Ivy Foundation Early Phase Clinical Trials Consortium conducted a randomized, multi-institution clinical trial to evaluate immune responses and survival following neoadjuvant and/or adjuvant therapy with pembrolizumab in 35 patients with recurrent, surgically resectable glioblastoma. Patients who were randomized to receive neoadjuvant pembrolizumab, with continued adjuvant therapy following surgery, had significantly extended overall survival compared to patients that were randomized to receive adjuvant, post-surgical programmed cell death protein 1 (PD-1) blockade alone. Neoadjuvant PD-1 blockade was associated with upregulation of T cell- and interferon-γ-related gene expression, but downregulation of cell-cycle-related gene expression within the tumor, which was not seen in patients that received adjuvant therapy alone. Focal induction of programmed death-ligand 1 in the tumor microenvironment, enhanced clonal expansion of T cells, decreased PD-1 expression on peripheral blood T cells and a decreasing monocytic population was observed more frequently in the neoadjuvant group than in patients treated only in the adjuvant setting. These findings suggest that the neoadjuvant administration of PD-1 blockade enhances both the local and systemic antitumor immune response and may represent a more efficacious approach to the treatment of this uniformly lethal brain tumor.

WHAT WE FOUND: Length of stay and time to surgery were significantly reduced after implementation of this admission pathway. Readmission rate was not adversely affected by this change. The protocol also significantly reduced the number of unnecessary body computed tomography imaging studies obtained in this patient population. CONFOUNDING FACTORS/REAL-LIFE IMPLICATIONS: The results of this study should be interpreted with their retrospective nature in mind. Further, analysis of this admission pathway did not take into consideration patient perspective or cost implications. Finally, the authors recognize that the resources for such an operational shift may only be found in large, tertiary, referral centers. Optimized specialized care for patients with new single brain masses promotes improved health care outcomes. It may also predictively reduce health care costs and improve patient satisfaction. More research is needed in this field. Limitations to our study included the inherent limitations of a retrospective pre-post design that can make it difficult to separate the effect of a specific intervention from other factors that change over time. In addition, assessment of patient satisfaction, use of diagnostic tests beyond body imaging, and advanced cost analysis could have strengthened this study. Lastly, it should be noted that the applicability of our approach may be limited to major tertiary centers with enough resources to implement such a pathway.

Chimeric antigen receptor (CAR) T cells have emerged as a promising class of cell-based immunotherapy in refractory malignancies. Neurotoxicity represents a common and potentially life-threatening adverse effect of CAR T cells, and clinical experience is limited. Here, we describe the clinical presentation and management of 25 adult patients who presented with neurotoxic syndromes after CAR T-cell therapy at the Massachusetts General Hospital. This cohort includes 24 patients treated with CD19-directed CAR T cells for non-Hodgkin lymphoma (n = 23) and acute lymphoblastic leukemia (n = 1), and 1 patient treated with α-fetoprotein–directed CAR T cells for hepatocellular carcinoma (n = 1). Twelve of the 25 patients (48%) developed grade 1-2 neurotoxicity and 13 patients (52%) presented with grade 3-4 neurotoxicity. We found that lower platelet counts at time of CAR T-cell infusion were associated with more severe neurotoxicity (P = .030). Cytokine release syndrome occurred in 24 of 25 patients (96%). Serum levels of ferritin peaked with onset of neurologic symptoms, and higher ferritin levels were associated with higher neurotoxicity grade. Grade 3-4 neurotoxicity correlated negatively with overall survival (OS) (P = .013). Median OS of the entire cohort was 54.7 weeks. Eight patients (32%) with grade 3-4 neurotoxicity were deceased at database closure, whereas none died with neurotoxicity grade 1-2. High pretreatment lactate dehydrogenase was frequently encountered in lymphoma patients with grade 3-4 neurotoxicity and correlated negatively with progression-free survival (P = .048). We did not find evidence that steroid use ≥7 days altered the patient’s outcome when compared with

BACKGROUND: ONC201 selectively antagonizes DRD2, crosses the blood-brain barrier and induces apoptosis in high grade gliomas and other advanced cancers. ONC201 efficacy is pronounced in glioma cells that harbor low DRD5 expression and is associated with induction of the ATF4/CHOP/DR5-mediated integrated stress response pathway. DRD2 antagonism also induces activation of NK and other immune cells. We previously reported the single agent activity of ONC201 in 17 adult patients with recurrent glioblastoma that demonstrated the safety, systemic pharmacodynamics, and a durable objective response when administered orally once every 3 weeks. Here, we evaluated the intratumoral drug concentrations and pharmacodynamic activity of ONC201 in adult recurrent glioblastoma patients that were treated on a weekly schedule. METHODS: Six patients >18 years old with first recurrence of glioblastoma who were eligible for salvage surgical resection were enrolled. ONC201 was administered orally as 625 mg once a week. Salvage surgery was performed approximately 24 hours after the second dose of ONC201 and patients continued on ONC201 until radiographic and/or clinical progression. Tumor tissue was flash-frozen and formalin-fixed for assessment of intratumoral drug concentrations by LC-MS and pharmacodynamics by IHC, respectively. RESULTS: Of the 6 enrolled patients, 5 had sufficient tissue for evaluation. Intratumoral drug concentrations exceeded therapeutic thresholds: median 1.5 µM (range 600 nM 9.3 µM). Investigation of biomarkers related to downstream signaling induced by ONC201 revealed heterogeneous intratumoral induction of ATF4/CHOP/DR5 expression and tumor cell apoptosis (TUNEL). Stronger induction of the pharmacodynamic signaling was associated with stronger induction of apoptosis and inversely associated with DRD5 expression, but not with drug concentration. No drug-related adverse events were reported in this cohort. Evaluation of immune cytokines and effectors molecules in serum and immune infiltration into the tumor is ongoing. CONCLUSIONS: ONC201 is biologically active and well tolerated in recurrent glioblastoma tumors when administered to adults.