Search

PURPOSE Pembrolizumab significantly improves clinical outcomes in advanced/metastatic microsatellite instability high (MSI-H)/deficient mismatch repair (dMMR) solid tumors but is not well studied in the neoadjuvant space. METHODS This is a phase II open-label, single-center trial of localized unresectable or high-risk resectable MSI-H/dMMR tumors. Treatment is pembrolizumab 200 mg once every 3 weeks for 6 months followed by surgical resection with an option to continue therapy for 1 year followed by observation. To continue on study, patients are required to have radiographic or clinical benefit. The coprimary end points are safety and pathologic complete response. Key secondary end points are response rate and organ-sparing at one year for patients who declined surgery. Exploratory analyses include interrogation of the tumor immune microenvironment using imaging mass cytometry. RESULTS A total of 35 patients were enrolled, including 27 patients with colorectal cancer and eight patients with noncolorectal cancer. Among 33 evaluable patients, best overall response rate was 82%. Among 17 (49%) patients who underwent surgery, the pathologic complete response rate was 65%. Ten patients elected to receive one year of pembrolizumab followed by surveillance without surgical resection (median follow-up of 23 weeks [range, 0-54 weeks]). An additional eight did not undergo surgical resection and received less than 1 year of pembrolizumab. During the study course of the trial and subsequent follow-up, progression events were seen in six patients (four of whom underwent salvage surgery). There were no new safety signals. Spatial immune profiling with imaging mass cytometry noted a significantly closer proximity between granulocytic cells and cytotoxic T cells in patients with progressive events compared with those without progression. CONCLUSION Neoadjuvant pembrolizumab in dMMR/MSI-H cancers is safe and resulted in high rates of pathologic, radiographic, and endoscopic response, which has implications for organ-sparing strategies.

OBJECTIVE Long-term follow-up of meningiomas has demonstrated recurrence rates ranging from 2.5% to 48% after 10 years, depending on histology grade. There are limited data available to guide the management of recurrent and previously irradiated skull base meningiomas, and challenges related to salvage surgery, reirradiation, and lack of clear systemic therapy strategies remain. In this study, the authors analyzed data from their experience with recurrent and previously irradiated meningiomas to assess the impact of salvage surgery and reirradiation on progression-free survival (PFS). METHODS A retrospective cohort study of 48 patients with recurrent and previously irradiated meningiomas who were treated between 1995 and 2021 was conducted. Data were extracted from medical records and included clinical, radiological, and pathologic reports. Patients were clustered according to WHO grades. The authors analyzed the complications related to reirradiation and salvage surgery and the impact of different treatment modalities on PFS using Cox proportional hazard ratios. RESULTS Forty-eight patients (33 with WHO grade I, 11 with WHO grade II, and 4 with WHO grade III meningiomas) were treated for 143 recurrences after their first radiation treatment. For WHO grade I meningiomas, there was no change in tumor control rates with adjuvant repeat radiotherapy (HR 0.784, 95% CI 0.349–1.759; p = 0.55), and in terms of extent of resection (EOR), subtotal resection (STR) alone was associated with an increased risk of recurrence when compared with gross-total resection (GTR) (HR 3.38, 95% CI 1.268–9.036; p = 0.0189). For WHO grade II meningiomas, GTR did not significantly confer improved tumor control relative to STR (HR 0.42, 95% CI 0.17–1.037; p = 0.055), but adjuvant repeat radiotherapy after STR was associated with improved outcomes (HR 0.316, 95% CI 0.13–0.768; p = 0.0029). Finally, for WHO grade III meningiomas, EOR did not correlate with outcomes (HR 0.75, 95% CI 0.22–2.482; p = 0.588), but repeat radiotherapy alone was associated with a decreased odds of progression (HR 0.276, 95% CI 0.078–0.97; p = 0.0028). CONCLUSIONS This study examined the impact of retreatment on PFS in a large cohort of patients with recurrent meningiomas that had been previously irradiated. At the time of recurrence, WHO grade I meningiomas exhibited improved PFS with GTR, subtotally resected WHO grade II meningiomas appeared to have improved PFS when reirradiated, and reirradiation in WHO grade III meningiomas showed improved PFS.

Supplementary Figure 4

Supplementary Figure 2

Supplementary Figure 1

Purpose:Cytomegalovirus (CMV) antigens occur in glioblastoma but not in normal brains, making them desirable immunologic targets.Patients and Methods:Highly functional autologous polyclonal CMV pp65-specific T cells from patients with glioblastoma were numerically expanded under good manufacturing practice compliant conditions and administered after 3 weeks of lymphodepleting dose-dense temozolomide (100 mg/m2) treatment. The phase I component used a 3+3 design, ascending through four dose levels (5 × 106–1 × 108 cells). Treatment occurred every 6 weeks for four cycles. In vivo persistence and effector function of CMV-specific T cells was determined by dextramer staining and multiparameter flow cytometry in serially sampled peripheral blood and in the tumor microenvironment.Results:We screened 65 patients; 41 were seropositive for CMV; 25 underwent leukapheresis; and 20 completed ≥1 cycle. No dose-limiting toxicities were observed. Radiographic response was complete in 1 patient, partial in 2. Median progression-free survival (PFS) time was 1.3 months [95% confidence interval (CI), 0–8.3 months]; 6-month PFS was 19% (95% CI, 7%–52%); and median overall survival time was 12 months (95% CI, 6 months to not reached). Repeated infusions of CMV-T cells paralleled significant increases in circulating CMV+ CD8+ T cells, but cytokine production showing effector activity was suppressed, especially from T cells obtained directly from glioblastomas.Conclusions:Adoptive infusion of CMV-specific T cells after lymphodepletion with dose-dense temozolomide was well tolerated. But apparently CMV seropositivity does not guarantee tumor susceptibility to CMV-specific T cells, suggesting heterogeneity in CMV antigen expression. Moreover, effector function of these T cells was attenuated, indicating a requirement for further T-cell modulation to prevent their dysfunction before conducting large-scale clinical studies.

Supplementary Figure 3

The brain tumor immune microenvironment (TIME) continuously evolves during glioma progression, but only a limited view of a highly complex glioma associated immune contexture across isocitrate dehydrogenase mutation (IDH) classified gliomas is known. Herein, we present an unprecedentedly comprehensive view of myeloid and lymphoid cell type diversity based on our single cell RNA sequencing and spectral cytometry-based interrogation of tumor-associated leukocytes from fifty-five IDH stratified primary and recurrent human gliomas and three non-glioma brains. Our analyses revealed twenty-two myeloid and lymphoid cell types within and across glioma subtypes. Glioma severity correlated with microglial attrition concomitant with a continuum of invading monocyte-derived microglia-like and macrophages amongst other infiltrating conventional T and NK lymphocytes and unconventional mucosa associated invariant T (MAIT) cells. Specifically, certain microglial and monocyte-derived subpopulations were associated with antigen presentation gene modules, akin to cross-presenting dendritic cells (DCs). Furthermore, we identified phagocytosis and antigen presentation gene modules enriched in Triggering receptor expressed on myeloid (TREM)-2+cells as a putative anti-glioma axis. Accelerated glioma growth was observed inTrem2deficient mice implanted with CT2A glioma cells affirming the anti-glioma role of TREM2+myeloid cells. In addition to providing a comprehensive landscape of glioma-specific immune contexture, our investigations discover TREM2 as a novel immunotherapy target for brain malignancies.

Background Surgical resection has been shown to prolong survival in patients with glioblastoma multiforme (GBM), although this benefit has not been demonstrated for reoperation following tumor recurrence. Laser interstitial thermal therapy (LITT) is a minimally invasive ablation technique that has been shown to effectively reduce tumor burden in some patients with intracranial malignancy. The aim of this study was to describe the safety and efficacy of LITT for recurrent and newly diagnosed GBM at a large tertiary referral center. Methods Patients with GBM receiving LITT were retrospectively analyzed. Overall survival from the time of LITT was the primary end point measured. Results There were 69 patients identified for inclusion in this study. The median age of the cohort was 56 years (range, 15–77 years). Median tumor volume was 10.4 cm3 (range, 1.0–64.0 cm3). A Kaplan-Meier estimate of median overall survival for the series from the time of LITT was 12 months (95% confidence interval 8–16 months). Median progression-free survival for the cohort from LITT was 4 months (95% confidence interval 3–7 months). Adjuvant chemotherapy significantly prolonged progression-free survival and overall survival (P Conclusions LITT can safely reduce intracranial tumor burden in patients with GBM who have exhausted other adjuvant therapies or are poor candidates for conventional resection techniques.

Ependymoma can occur anywhere in the central nervous system (CNS), but often occurs near the ventricle of the brain and central canal of the spinal cord. Ependymoma accounts for 5.7% of all childhood and 1.9% of all adult CNS tumors. RELA fusion-positive ependymoma is a subgroup associated with supratentorial location, higher WHO grade and worse prognosis. Diffuse Midline Glioma (DMG) is another relatively rare CNS tumor, originating in the midline locations of the brain (including thalamus, pons and spinal cord), accounting for 10% of all childhood and less than 4% of adult CNS tumors. For ependymoma standard treatment includes surgery and radiation therapy, with limited systemic options other than clinical trials for recurrent disease. For DMG, surgical intervention is restricted to biopsy, with radiation as standard therapy. Systemic options for both ependymoma and DMG are limited.VAL-083 is a bi-functional DNA-targeting agent which rapidly induces inter-strand DNA cross-links at N7-guanine inducing double-strand breaks causing cell death and acts independent of MGMT DNA repair and H3F3 K27M mutation status in high-grade gliomas. We report on 2 patients: one with ependymoma and one with DMG, treated with VAL-083 under an expanded access program. Both patients had recent disease progression and limited therapeutic options. Case #1: a 47-year-old male who was diagnosed with a left parietal high grade (3) anaplastic ependymoma and with IDHwt and unmethylated MGMT promoter status. Inter- and intragenic fusion analysis of tumor tissue revealed RELA fusion-positive ependymoma. He had undergone 2 resections and had received radiation and multiple systemic treatment regimens. Case #2: a 21-year-old male who was diagnosed with DMG of the brain stem, with IDHwt and unmethylated MGMT promoter status. He had undergone radiation therapy, and multiple treatment regimens. Both patients were not eligible to participate in any clinical trial and received VAL-083 under an expanded access program. They initiated treatment with VAL-083 (30 mg/m2 for 3 consecutive days every 21 days) and have completed 3 cycles. Both are neurological and radiological stable, they continue to receive VAL-083. No adverse events have been reported and no dose reductions have been required. These cases highlight that VAL-83 may be a treatment option for recurrent RELA fusion-positive ependymoma and DMG refractory to other treatment regimens. Additional safety and efficacy outcomes related to patient status will be presented at the meeting.Clinicaltrials.gov Identifier: NCT03138629. The treatment plans for this EAP patient were approved by MD Anderson Cancer Center IRB. Citation Format: Carlos Kamiya-Matsuoka, Stephanie Knight, Teresa Hanna, Timothy A. Gregory, John Langlands, Dennis Brown, Vinay K. Puduvalli. RELA fusion-positive ependymoma and diffuse midline glioma treated with VAL-083 under expanded access - case reports [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 LB126.

Current standard-of-care for glioblastoma (GBM) includes surgery followed by concurrent therapy with radiation and temozolomide (TMZ) and adjuvant TMZ. Almost all GBM patients experience recurrent/progressive disease despite upfront standard of care treatment, with a median overall survival of 3-9 mo. after recurrence. There are limited treatment options available upon progression of disease which may include potential participation in clinical trials. However, patients may not meet the strictly defined entry criteria to participate in these clinical trials. VAL-083 is a first-in-class bifunctional alkylating agent that acts independent of O6-methylguanine-DNA-methyltransferase (MGMT) methylation status. Under an Expanded Access (EA) program, we have treated 24 patients with recurrent GBM, who were not eligible to participate in clinical trials with VAL-083. Four (4/24; 17%) patients had leptomeningeal disease (LMD) at time of enrolment. While safety data was assessed for all patients, those without LMD (20 patients) were evaluated for efficacy. All patients evaluated for efficacy received chemoradiation with TMZ, and the mean number of adjuvant TMZ cycles was 5 (± 6.2). The median time from last progression to start of VAL-083 was 0.65 mo. (95%CI: 0.32-1.55) and median KPS was 80 (25-75P: 70-90). Eight (8/20; 40%) patients had 2 or more prior recurrences, 9/20 (45%) patients had multifocal disease, and 5/20 (25%) had prior lomustine. Eighteen (18/20; 90%) patients had unmethylated promoter status for MGMT and 18/20 (90%) were IDH wild type. All patients had at least 1 mutation, with 11/20 (55%) having 5 or more mutations, and one patient had hypermutator phenotype with MSH6 mutation. The most common mutations were, TERT 11/20 (55%), PTEN 9/20 (45%), and TP53 6/20 (30%). All patients started treatment with VAL-083 at 30 mg/m2 administered on 3 consecutive days every 21 days. Seven patients received bevacizumab concurrently with VAL-083. VAL-083 was well tolerated and the main adverse events were consistent with prior experience, i.e., thrombocytopenia and neutropenia. Eight (8/24; 33%) patients had a dose reduction, 7 of which were due to thrombocytopenia, and 1 due to neutropenia. Five patients with thrombocytopenia had prior lomustine. As of cut-off date (05 Jan, 2023), median progression free survival (mPFS) and median overall survival (mOS) from last disease progression was 5.9 mo (95%CI: 3.9-7.9) and 9.4 mo (95%CI: 3.0-14.3), respectively. In patients without multifocal disease mOS was even longer, 14.3 mo (95%CI: 3.9-14.3). Use of VAL-083 in this expanded access study showed benefit in the treatment of recurrent GBM patients even those who have had multiple recurrences and were not candidates for the treatment through clinical trial. Additional safety and efficacy measures will be presented at the meeting.Clincialtrials.gov Identifier: NCT03138629. All EA treatment requests and plans were approved by MD Anderson Cancer Center IRB. Citation Format: Carlos Kamiya-Matsuoka, Shiao-Pei Weathers, Rebecca A. Harrison, Nazanin K. Majd, Ashley E. Aaroe, Stephanie Knight, Teresa Hanna, Timothy A. Gregory, John Langlands, Dennis Brown, Vinay K. Puduvalli. VAL-083 in patients with recurrent glioblastoma treated under expanded access program [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 LB127.

Gliomas are recalcitrant brain tumors. Differential tumor immune reactivity contributes to survival advantage of isocitrate dehydrogenase-mutant (IDHmut) over wild-type (IDHwt) gliomas. Despite this correlative pattern of immunity and survival, only a limited view of a highly complex immune contexture across IDH mutation classified gliomas is known. Herein, we present an unprecedented view of myeloid and lymphoid cell type diversity by single cell RNA sequencing and spectral cytometry-based interrogation of tumor-associated leukocytes from fifty-five IDH stratified primary and recurrent human gliomas and six non-glioma brains. Our analyses revealed twenty-two myeloid and lymphoid cell types within and across glioma subtypes. Glioma severity in relapsed IDHwt correlated with microglial attrition concomitant with a continuum of invading monocyte-derived microglia-like and macrophages amongst other infiltrating conventional T and NK lymphocytes and unconventional mucosa associated invariant T (MAIT) cells. Specifically, certain microglial and monocyte-derived subpopulations were associated with antigen presentation gene modules, akin to cross-presenting dendritic cells (DCs). As tissue macrophages exhibit multifaceted polarization in response to microenvironmental cues, we clarify the existence of microglia/macrophage functional states beyond M1/M2 paradigms exemplified by the presence of palmitic-, oleic- acid, and glucocorticoid responsive polarized states. Immune related gene ontology analysis identified enriched antigen presentation and phagocytosis gene modules in distinct microglia-like clusters. Importantly, the phagocytic immunomodulator; Triggering Receptor Expressed on Myeloid Cells 2 (TREM2) was upregulated in these microglia-like cells. Contrary to tumor promoting role of TREM2 myeloid cells in non-brain cancers, we identify TREM2 mediated anti-glioma axis as a regulator of antigen presentation Accelerated glioma growth was observed in Trem2 deficient mice implanted with CT2A glioma cells affirming the anti-glioma role of TREM2+ myeloid cells. In addition to providing an advanced landscape of glioma-specific immune contexture for immunotherapy applications, our reverse translational investigations discover TREM2 as a novel immunotherapy target for brain malignancies. Citation Format: Pravesh Gupta, Minghao Dang, Shivangi Oberai, Mekenzie Peshoff, Nancy Milam, Aml Ahmed, Krishna Bojja, Tuan M. Tran, Kathryn Cox, Huma Shehwana, Carlos Kamiya Matsuoka, Jianzhuo Li, Joy Gumin, Alicia Goldman, Sameer A. Seth, Atul Maheshwari, Frederick F. Lang, Nicholas E. Navin, Amy B. Heimberger, Karen Clise Dwyer, Linghua Wang, Krishna P. Bhat. Immunophenotyping of human brain tumors reveals myeloid cell mediated anti-glioma axis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 669.

While targeting oxidative phosphorylation (OXPHOS) is a rational anticancer strategy, patient benefit with OXPHOS inhibitors in the clinic has yet to be achieved. Based on promising preclinical data, we advanced IACS-010759, a highly potent and selective small-molecule inhibitor of mitochondrial complex I, into two phase I trials in patients with acute myeloid leukemia (NCT02882321) or advanced solid tumors (NCT03291938). Clinical findings revealed that IACS-010759 had a narrow therapeutic index with emergent dose-limiting toxicities that included elevated blood lactate and neurotoxicity, obstructing efforts to maintain target plasma exposure. Consequently, only modest on-target inhibition and limited antitumor activity were observed. Follow-up reverse translational studies uncovered that IACS-010759 reduced oxygen consumption rates in neurons and damaged myelin. Further, IACS-010759-treated mice displayed behaviors indictive of neuropathy, which were minimized with the co-administration of a histone deacetylase 6 inhibitor. Our findings urge caution in the continued development of complex I inhibitors as antitumor agents.

BackgroundPineal parenchymal tumors are exceedingly rare brain tumors responsible for less than 1% of all adult primary intracranial malignancies in the United States. In this study, we describe the clinicopathologic features, management, and outcomes of patients with pineal parenchymal tumor of intermediate differentiation (PPTID).MethodsWe describe a single-center, multidisciplinary team experience in managing PPTID patients over a 15-year period (January 2000 to January 2015) at The University of Texas MD Anderson Cancer Center (MDACC). Pathology was reviewed by the pathology collaborators (A.G. and G.N.F.) and retrospective chart review was performed for treatment and clinical outcomes.ResultsWe identified 17 patients (9 male) with diagnosis of PPTID. Median age at diagnosis of PPTID was 37 years (range, 15-57 years). Follow-up ranged from 0.1 to 162.8 months with 6 reported deaths. Most patients presented with headaches and diplopia. Three patients had neuroaxial dissemination at initial diagnosis, and recurrence of tumor was common (7/16) despite treatment.ConclusionsNo clear prognostic factors were identified in this series. Extension of resection showed a trend toward improved survival. PPTID with neuroaxial dissemination benefits from aggressive initial treatment including craniospinal irradiation and adjuvant chemotherapy, whereas localized disease may be treated traditionally with maximum debulking followed by adjuvant radiotherapy alone. Long-term monitoring is recommended for neurotoxicity and/or late recurrence.

Background Primary spinal high-grade gliomas (S-HGG) are rare aggressive tumors; radiation therapy (RT) often plays a dominant role in management. We conducted a single-institution retrospective review to study the clinicopathological features and management of S-HGGs. Methods Patients with biopsy-proven S-HGG who received RT from 2001 to 2020 were analyzed for patient, tumor, and treatment characteristics. Kaplan–Meier estimates were used for survival analyses. Results Twenty-nine patients were identified with a median age of 25.9 years (range 1–74 y). Four patients had GTR while 25 underwent subtotal resection or biopsy. All patients were IDH wildtype and MGMT-promoter unmethylated, where available. H3K27M mutation was present in 5 out of 10 patients tested, while one patient harbored p53 mutation. Median RT dose was 50.4 Gy (range 39.6–54 Gy) and 65% received concurrent chemotherapy, most commonly temozolomide. Twenty-three (79%) of patients had documented recurrence. Overall, 16 patients relapsed locally, 10 relapsed in the brain and 8 developed leptomeningeal disease; only 8 had isolated local relapse. Median OS from diagnosis was 21.3 months and median PFS was 9.7 months. On univariate analysis, age, gender, GTR, grade, RT modality, RT dose and concurrent chemotherapy did not predict for survival. Patients with H3K27M mutation had a poorer PFS compared to those without mutation (10.1 m vs 45.1 m) but the difference did not reach statistical significance (P = .26). Conclusions The prognosis of patients with spinal HGGs remains poor with two-thirds of the patients developing distant recurrence despite chemoradiation. Survival outcomes were similar in patients ≤ 29 years compared to adults > 29 years. A better understanding of the molecular drivers of spinal HGGs is needed to develop more effective treatment options.

The immune cell composition of isocitrate dehydrogenase wild type (IDH-wt) glioma patients significantly differs compared to IDH-mutant (IDH-mut) yet a detailed and unbiased understanding of their transcriptomic and epigenetic landscapes remains elusive. To this end, we performed single-cell RNA-sequencing (scRNA-seq) and single-cell Assay for Transposase-Accessible Chromatin using sequencing (sc-ATAC-seq) on ~100,000 tumor-associated immune cells from seventeen IDH mutation classified primary and recurrent human gliomas and non-glioma brains (NGBs). Our analyses revealed sixty-two transcriptionally distinct myeloid and lymphoid cell states within and across glioma subtypes and we noted microglial attrition with increasing disease severity concomitant with invading monocyte-derived cells (MDCs) and lymphocytes. Specifically, certain microglial and monocyte-derived subpopulations were associated with antigen presentation gene modules, akin to cross-presenting dendritic cells. As tissue macrophages exhibit multifaceted polarization in response to microenvironmental cues, we clarify the existence of microglia/macrophage functional states beyond M1/M2 paradigms exemplified by the presence of palmitic-, oleic- acid, and glucocorticoid responsive polarized states. We identified cytotoxic T cells with poly-functional cytolytic states mostly in recurrent IDH-wt gliomas. Furthermore, ligand-receptor interactome analyses showed a preponderance of antigen presentation/phagocytosis over the checkpoint axis in IDH-wt compared to IDH-mut gliomas. Additionally, our sc-ATAC-seq analyses revealed differences in regulatory networks in NGBs, IDH-mut, and IDH-wt glioma-associated immune cells. In particular, we noted reduced microglial usage of an iron recycling SPIC transcription factor and Interferon Regulatory Factors (IRFs); IRF1 and IRF2 in IDH-wt relative to IDH-mut and NGBs. Unique features such as amplification of 11-Zinc Finger Protein accessibility were restricted to MDCs. Finally, sc-ATAC-seq profiles of CD8+ exhausted T cells from IDH-wt showed strong enhancer accessibility on CTLA-4, Layilin, and TIM-3 but no enrichment on PD1 was seen. In summary, our study provides unprecedented granular detail of transcriptionally and epigenomically defined glioma-specific immune contexture that can be exploited for immunotherapy applications.

Current standard-of-care for glioblastoma (GBM) includes surgery followed by radiation with concurrent and adjuvant temozolomide. There are limited treatment options available upon progression or recurrence of disease. Options often involve participation in clinical trials with promising new therapies. However, patients may not meet the strictly defined entry criteria to participate in these clinical trials. Under an Expanded Access (EA) program, we have treated 14 recurrent GBM patients with VAL-083, they were not eligible to participate in other clinical trials. The median time from last progression to start of VAL-083 was 1.0 month (95%CI:0.09-2.67). All patients had received chemoradiation with temozolomide. Five (5/14;36%) patients had ≥ 2 recurrences, 8/14 (57%) had multifocal disease, and the median KPS was 80 (95%CI:70-90). All patients had unmethylated MGMT promoter, 13/14 (93%) were IDH-WT, 9/14 (64%) had a TERT promoter mutation, 6/14 (43%) had a PTEN mutation, and 4/14 (28%) had an EGFR mutation. All patients received treatment with VAL-083 at 30 mg/m2 x 3 days every 21 days. Five patients with cerebral edema refractory to steroids received bevacizumab (BEV;10 mg/kg) concurrently with VAL-083, and 8 patients received dexamethasone (Dex; >4 mg/day) with VAL-083. This is the first report of the use of VAL-083 in combination with BEV (VAL-03/BEV).The main adverse event was thrombocytopenia consistent with prior experience. Four (4/14; 28%) patients had a dose reduction, 3 of which were due to thrombocytopenia. No patients had a dose reduction while receiving VAL-083/BEV. Two patients who progressed on VAL-083, were later treated with CCNU, and myelosuppression was not observed.Median progression-free survival (mPFS) and median overall survival (mOS) from last progression were 5.7 months (95%CI:1.3-7.9) and 8.3 months (95%CI:3.0-14.3), respectively. Additional treatment, safety and outcome data will be presented at the meeting.Clinicaltrials.gov Identifier: NCT03138629. EA treatment plans were approved by MD Anderson Cancer Center IRB.

Ependymoma is a relatively rare central nervous system tumor accounting for 2-9 % of all neuroepithelial tumors. RELA fusion-positive ependymoma is a subgroup associated with supratentorial location, higher WHO grade and worse prognosis. In addition, there is no standard systemic chemotherapy treatment for adults with recurrent disease. VAL-083 is a bi-functional DNA-targeting agent which rapidly induces inter-strand DNA cross-links at N7-guanine inducing double-strand breaks causing cell death and acts independent of MGMT DNA-repair in high-grade gliomas. We report a 40-year-old male who was initially diagnosed with a right parieto-occipital high-grade glioma, with no somatic mutations including IDH1/2 genes, and with unmethylated MGMT promoter status. He initially underwent gross total resection, followed by chemoradiation with concurrent and adjuvant temozolomide for 12 cycles. Sixteen months later, he developed recurrent disease and had a second resection. Inter- and intragenic fusion analysis of tumor tissue revealed C11orf95-RELA fusion and the diagnosis of RELA fusion-positive ependymoma was established. The patient was not eligible to participate in any clinical trial and received VAL-083 under an expanded access program. He was then treated with VAL-083 (30 mg/m2 for 3 consecutive days every 21 days) and completed 12 cycles during a period of 9 months. No grade 3/4 adverse events such as thrombocytopenia, anemia, neutropenia, or lymphopenia were observed. His liver and renal functions were normal. No dose reduction was required. He also received levetiracetam, alprazolam and prochlorperazine, with no drug interactions. Steroid were not required. He has been under surveillance since completion of systemic treatment with VAL-083 and has remained radiologically stable, with no CSF dissemination, after 12 months. This case highlights that VAL-083 may be a treatment option for recurrent RELA fusion-positive ependymoma refractory to temozolomide-based regimens. Clinicaltrials.gov Identifier: NCT03138629. The treatment plans for this EAP patient were approved by MD Anderson Cancer Center IRB.

BCR-ABL1 tyrosine kinase inhibitors (TKIs) alone and with chemotherapy led to a dramatic increase in survival of chronic myeloid leukemia (CML) and Philadelphia-positive acute lymphoblastic leukemi...

Immune checkpoint inhibitors (CPIs) (anti-cytotoxic T-lymphocyte antigen-4, anti-programmed death 1, and anti-programmed death-ligand 1) have transformed the landscape of cancer therapy. However, their increasing use has unleashed immune-related adverse events in various organs, among which neurologic ones, while rare, are increasingly being recognized and remain incompletely characterized. Herein, we report five patients with nonmelanoma cancers who developed weakness after receiving CPIs. The etiology was attributed to radiculoneuritis (one patient), myositis (one patient), Miller Fisher/myasthenia gravis (MG) (one patient), neuropathy/myositis/MG (one patient), and myositis/MG (one patient). Weakness developed after a median of two doses (range: 1–3) and 4 weeks (range: 3–10) from initiation of therapy. Two patients had severe manifestations without improvement while the other three experienced partial improvement despite discontinuation of the CPI (s) and initiation of immunosuppressive therapy. A review of literature identified 62 similar cases. This report highlights the challenges in the diagnosis and management of neurologic adverse events related to the use of CPIs. It also addresses the crucial need for early recognition, proper workup, and better biomarkers to help improve the outcomes of these adverse events.

Background It is estimated only 8–11% of patients with glioblastoma (GBM) enrol in clinical trials, limiting treatment development. We analysed the clinical and demographic features of patients with GBM enroled in clinical trials at the University of Texas MD Anderson Cancer Center (MDACC). Methods We reviewed the records of adult patients treated for primary GBM between 2007 and 2012 at the MDACC. A total of 755 patients were identified: 133 were deemed non-eligible, 111 were deemed trial eligible but received standard care and 511 participated in a clinical trial (311 for newly diagnosed glioblastoma [nGBM] and 200 for recurrent glioblastoma [rGBM]). Population characteristics were analysed using descriptive statistics, and survival end-points were evaluated with the Kaplan–Meier method. Results The median age of clinical trial participants and trial eligible patients was 53.2 years (standard deviation 12.1). Most patients (49.4%) were enroled in a clinical trial protocol for nGBM. The majority of nGBM trial participants were male patients (65.1%), white (86.3%), married (84.4%) and in state (59.9%). Employment status, education, symptoms, tumour location, performance status, extent of resection and treatment facility differed between nGBM trial participants and non-participants. Patients who were eligible but did not enrol tended to be older, have worse performance status and live farther away from the MDACC. Conclusion Numerous disease and demographic barriers exist in trial enrolment in patients with GBM. This study highlights some of these obstacles, which require attention to improve patient enrolment to clinical trials. Patient and physician engagement in novel therapeutic strategies is essential to improving outcomes in this disease.

Background: Glioblastoma (GBM) is the most common primary malignant brain tumor in adults. Management includes surgical resection followed by chemoradiation, and prognosis remains poor. Surgical resection is not possible for some deep-seated or eloquent tumors. Laser interstitial thermal therapy (LITT) has emerged as a new, minimally invasive surgical option for deep-seated GBM. Case Description: We report a case of newly diagnosed thalamic GBM managed with LITT followed by radiation and chemotherapy. Conclusion: The patient remains well at 50-month post-LITT, indicating a potentially unique durability of LITT treatment in GBM.

BACKGROUND Primary spinal high-grade gliomas(S-HGG) are rare, aggressive tumors and radiation therapy(RT) plays a dominant role in the management given their infiltrative nature. We conducted a single-institution retrospective review to study the clinicopathological features and management of S-HGGs. METHODS Patients with biopsy-proven S-HGG who received RT from 2001-2020 were analyzed for patient, tumor, and treatment characteristics. Kaplan-Meier estimate and Cox proportional hazard regression method were used for survival analyses. RESULTS Twenty-nine patients were identified with a median age of 25.9 years (range 1-74y). Four patients had gross total resection(GTR) while 25 underwent subtotal resection or biopsy. Nineteen patients had WHO grade 4 tumor. IDH1 mutation and MGMT promoter methylation were analyzed in 14 and four patients respectively; all were IDH wildtype and MGMT-promoter unmethylated. H3K27M mutation was present in five out of 10 patients tested. Twenty-two patients received photon-based radiation and 7 received proton therapy. Median RT dose was 50.4 Gy (range 39.6-54Gy) with 79% receiving >45Gy. 65% patients received concurrent chemotherapy, most commonly temozolomide. Twenty-three (79%) patients had documented recurrence. Overall, 16 patients relapsed locally, 10 relapsed in the brain and 8 developed leptomeningeal disease; only 8(35%) had isolated local relapse. Median OS from diagnosis was 21.3 months and median PFS after RT was 9.7 months. On univariate analysis, age, sex, GTR, grade, RT modality, RT dose and concurrent chemotherapy did not predict for survival. Patients with H3K27M mutation had a poorer median PFS after RT compared to those without the mutation but the difference did not reach statistical significance (p = 0.26). CONCLUSIONS Although 86% of patients had gross disease at RT and received a lower median RT dose than typically used in cerebral high-grade gliomas, only 55% of patients failed locally. H3K27M mutation may portend worse survival; future studies to improve the therapeutic approach in these patients are warranted.

Background Glioblastoma (GBM) is the most common and most aggressive primary malignant brain tumour. The standard of care is surgical resection, followed by radiotherapy with concurrent and adjuvant temozolomide. In Latin America, there is scarcity of information about the incidence of GBM and even less data regarding outcomes. In this study, we describe the clinicopathologic features, management and outcomes of GBM patients. Methods We describe a single-centre multidisciplinary team experience in managing GBM patients over an 11-year period (Jan 2005 to Dec 2016). Pathology was reviewed by the pathology collaborator and retrospective chart review performed for treatment and clinical outcomes. Results We identified 74 patients (50 males) with diagnosis of GBM. Median age at diagnosis was 58 years (range 24-79 years), and median Karnofsky performance status was 80%. Forty-three (58.1%) went to gross total resection, 20 (27%) partial resection and 11 (14.9%) biopsy. Sixty-four (87%) patients received Stupp regimen. The median overall survival (OS) was 13.9 months (standard error (SE) 1.71; 95% confidence interval (CI), 10.56-17.23). In patients treated according to Stupp regimen, the progression-free survival (PFS) was 10 months (SE 1.8; 95% CI, 6.481-13.519), the selfcare survival was 11.8 months (SE 1.61; 95% CI, 8.632-14.968) and the OS was 16.1 months (SE 1.53; 95% CI, 13.01-19.099). Conclusions This study reports the most complete analysis of epidemiology, clinical management and outcomes of patients with diagnosis of GBM in Chile treated with Stupp regimen. The PFS and OS are consistent with reports of US and Europe.

2006 Background: Checkpoint inhibitor (CPI) therapy has demonstrated overall limited efficacy in the treatment of GBM. Sixty newly diagnosed GBM patients unselected for MGMT status underwent treatment with concurrent atezolizumab with radiation therapy and TMZ followed by adjuvant atezolizumab and TMZ (NCT03174197). Clinical data has been reported previously. Methods: Genomic (WES with somatic mutation and SCNA determination N = total 42 samples, 33 baseline, 9 TP-2), transcriptomic (RNA seq N = total 72 samples, 54 baseline, 18 TP-2), and metagenomic sequencing of fecal samples (N = total 45 samples, 26 pre samples, 13 post RT samples, six 6m samples) analyses were conducted on pre-treatment samples. Findings were correlated with clinical outcome including OS and PFS. Twenty of the 60 patients underwent re-resection for suspected recurrent disease of which nine patients had WES and RNA seq performed successfully on paired pre and post treatment samples. Results: Somatic mutation, copy number and ploidy profiles were consistent with known aberrations in GBM. An unsupervised molecular network-based stratification of pre-treatment tumor mutations resulted in patients being grouped in 3 clusters with survival difference. Patients with GBM harboring an EGFR aberrancy were associated with a relatively worse mOS following treatment compared to patients with tumors enriched with PTEN alterations, while patients with IDH1 mutations had the longest mOS. Gene set enrichment analysis of gene expression in tumors from patients ( < mOS vs ≥mOS) identified genes associated with lymphocyte activation and immune response in patients with longer survival (p < 0.01) Unsupervised hierarchical clustering of bacterial taxa demonstrated two distinct clusters with significant difference by OS. Survival analysis and Analysis of Compositions of Microbiomes with Bias Correction (ANCOM-BC) revealed distinct taxa associated with OS ( Ruminococcus spp.) and response to treatment ( Eubacterium spp.), respectively. Conclusions: In this small CPI-treated GBM cohort, WES, SCNA and RNA seq identified pre-treatment tumor features that separated patients by survival. The fecal microbiome observations in our GBM cohort warrants further investigation. Clinical trial information: NCT03174197.

Current standard-of-care for glioblastoma (GBM) includes surgery followed by concurrent therapy with radiation and temozolomide (TMZ) followed by adjuvant TMZ. Almost all GBM patients experience recurrent/progressive disease despite upfront standard of care treatment, with a median survival after recurrence of 3–9 months. Unmethylated promoter for O6-methylguanine-DNA-methyltransferase (MGMT) is a validated biomarker for TMZ-resistance and is correlated with poor patient prognosis. VAL-083 is a bi-functional DNA-targeting agent which rapidly induces inter-strand cross-links at N7-guanine inducing double-strand breaks causing cell death and acts independent of MGMT DNA repair. This trial is an open-label two-arm biomarker-driven phase 2 clinical trial in MGMT-unmethylated bevacizumab-naïve GBM patients with either recurrent (Group 1) or newly diagnosed GBM requiring adjuvant therapy after chemo-radiation with temozolomide (Group 2). Patients receive VAL-083 IV at 30 or 40 mg/m2/d on days 1, 2, and 3 of a 21-day cycle. The primary objective of this study is to determine the effect of VAL-083 on median overall survival (mOS) in MGMT-unmethylated recurrent GBM patients (Group 1); and progression-free survival (PFS) in newly diagnosed GBM patients requiring adjuvant therapy after chemo-irradiation with temozolomide (Group 2), compared to historical controls in both groups. Tumor response will be assessed by MRI every 42 days, using RANO criteria. The initial starting dose in this study was 40 mg/m2/d on days 1, 2, and 3 of a 21-day cycle, which was subsequently reduced to 30 mg/m2/d to improve tolerance due to myelosuppression. As of June 2-2020, 35 patients with recurrent GBM (Group 1) have received 40 mg/m2/d and 39 patients have received 30 mg/m2/d VAL-083. In the adjuvant setting (Group 2), 25 patients have been enrolled (30 mg/m2/day). Enrollment, safety data and study updates will be presented at the meeting. Clinicaltrials.gov identifier: NCT02717962.

Pituitary carcinoma is an aggressive tumor characterized by metastatic spread beyond the sellar region that leads to debilitating symptoms and poor survival. Pituitary carcinomas recur despite conventional multimodality treatments. Given the recent advances in the use of immune checkpoint inhibitors (CPIs) to treat various solid cancers, there is interest in exploring the role of immunotherapy for treating aggressive, refractory pituitary tumors. We treated four pituitary carcinoma patients with pembrolizumab as part of a phase II clinical trial (NCT02721732). Here, we present their clinical course and outcomes and correlate responses with available molecular data: hypermutation status, PD-L1 staining, tumor-infiltrating lymphocyte score, microsatellite status and tumor mutational burden. Patients 1 and 2, with heavily pretreated, refractory corticotroph pituitary carcinoma, had partial radiographic (60% and 32% per irRECIST, respectively) and hormonal responses. Patient 1’s response continues 42 months after initiation of pembrolizumab and his baseline tumor tissue obtained after treatment with temozolomide demonstrated a hypermutator phenotype with MSH2 and MSH6 gene mutations. Patient 2’s tumor was not sampled after exposure to temozolomide, but prior somatic mutational testing was negative. Patient 3 (non-functioning corticotroph tumor) had a best response of stable disease for four months. Patient 4 (prolactin-secreting carcinoma) had progressive disease. The latter two patients’ tumors did not demonstrate a hypermutator phenotype after treatment with temozolomide. PD-L1 staining was negative in all tumors. TIL score was 2 in Patients 1 and 4, negative in Patient 3 and not available in Patient 2. All patients tolerated the treatment well with mild adverse events. Our study generates the hypothesis that an alkylating agent-induced hypermutator phenotype may be an indicator of response to CPIs in pituitary carcinomas. The role of CPI in treating patients with pituitary carcinoma and mechanisms of hypermutation in this population require further study.

BACKGROUND WHO grade II and III IDH wild-type astrocytomas behave more aggressively than their IDH mutated counterparts. A subpopulation shares molecular features with the novel entity proposed in cIMPACT-NOW Update 3 “Diffuse astrocytic glioma, IDH wild-type, with molecular features of glioblastoma (GBM), WHO IV”. METHODS We performed a retrospective analysis of clinical and molecular features, management and survival of 134 adult patients treated for grade II and III IDH wild-type astrocytoma between 06/2012 and 12/2018 at MD Anderson Cancer Center (MDACC - 112) and UT Health Science Center at Houston (UTHSC - 22). All patients had IDH1 sequenced, all but 2 had IDH2 sequenced, and 73 had further next generation sequencing. RESULTS Median age at diagnosis was 53 (interquartile range 18-83). 82 patients (61%) were male. 31 patients were histologically diagnosed with grade II astrocytoma, 102 with grade III astrocytoma, and one with diffuse glioma (insufficient tissue to render histologic grade or perform sequencing). EGFR alterations were found in 31 patients and TERT promoter mutations in 22. 84 (63%) received concurrent chemoradiation and adjuvant temozolomide (grade II, n=9; grade III, n=74; NOS, n=1). PFS overall was 12.0 months (grade II = 17.9; grade III = 10.7). OS in patients treated with concurrent chemoradiation and adjuvant temozolomide was 17.1 months versus 17.7 in patients treated with sequential radiation and temozolomide (p = NS), and 10.6 in patients treated with RT alone or surveillance (p< 0.016). The highest 2-year OS was seen in grade II patients treated with concurrent chemoradiation and adjuvant temozolomide (60%). CONCLUSIONS WHO grade II and III IDHwt astrocytoma survival is similar to historical GBM cohorts. The proportion meeting molecular criteria for GBM is yet undefined. Groups who received chemotherapy may perform better than those who do not. Further analysis of MGMT methylation and other molecular factors is ongoing.

In the 2016 WHO classification of CNS tumors, oligodendrogliomas are molecularly defined by IDH1 or IDH2 mutations and 1p/19q co-deletion. Some reports suggest that PI3K pathway alterations may confer increased risk of progression and poor prognosis in oligodendroglioma. However, factors that influence prognosis in molecularly defined oligodendroglioma (mOGD) have not been thoroughly studied. Also, the benefits of adjuvant radiation and temozolomide in mOGDs remain to be determined. 107 mOGDs diagnosed between 2008-2018 at the University of Texas Health Science Center at Houston (n= 39) and MD Anderson Cancer Center (n= 68) were included. A retrospective review of the demographic, clinical, histologic, molecular, and outcomes were performed. Median age at diagnosis was 37 years and 61 (57%) patients were male. There were 64 (60%) WHO Grade 2 and 43 (40%) WHO Grade 3 tumors. Ninety-five (88.8%) tumors were IDH1-mutant and 12 (11.2%) were IDH2-mutant. Eighty-two (77%) patients were stratified as high-risk: older than 40-years and/or subtotal resection (RTOG 9802). Gross-total resection was achieved in 47 (45%) patients. Treatment strategies included observation (n= 15), temozolomide (n= 11), radiation (n= 13), radiation with temozolomide (n= 62) and other (n= 6). Our results show a benefit of temozolomide vs. observation in progression-free survival (PFS). However, no benefit in PFS or overall survival (OS) was observed when comparing radiation vs. radiation with temozolomide. PIK3CA mutations were detected in 15 (14%) cases, and patients with PIK3CA-mutant mOGDs showed worse OS (10.7-years vs 15.1-years, p= 0.009). Patients with WHO Grade 3 tumors had shorter PFS but no significant difference in OS was observed compared to grade 2. Our findings suggest that mOGDs harboring PIK3CA mutations have worse OS. Except for an advantage in PFS in temozolomide treated patients, adjuvant treatment with radiation or the combination of both, showed no significant advantage in terms of OS.

Purpose: Cytomegalovirus (CMV) antigens occur in glioblastoma but not in normal brains, making them desirable immunologic targets. Patients and Methods: Highly functional autologous polyclonal CMV pp65-specific T cells from patients with glioblastoma were numerically expanded under good manufacturing practice compliant conditions and administered after 3 weeks of lymphodepleting dose-dense temozolomide (100 mg/m2) treatment. The phase I component used a 3+3 design, ascending through four dose levels (5 × 106–1 × 108 cells). Treatment occurred every 6 weeks for four cycles. In vivo persistence and effector function of CMV-specific T cells was determined by dextramer staining and multiparameter flow cytometry in serially sampled peripheral blood and in the tumor microenvironment. Results: We screened 65 patients; 41 were seropositive for CMV; 25 underwent leukapheresis; and 20 completed ≥1 cycle. No dose-limiting toxicities were observed. Radiographic response was complete in 1 patient, partial in 2. Median progression-free survival (PFS) time was 1.3 months [95% confidence interval (CI), 0–8.3 months]; 6-month PFS was 19% (95% CI, 7%–52%); and median overall survival time was 12 months (95% CI, 6 months to not reached). Repeated infusions of CMV-T cells paralleled significant increases in circulating CMV+ CD8+ T cells, but cytokine production showing effector activity was suppressed, especially from T cells obtained directly from glioblastomas. Conclusions: Adoptive infusion of CMV-specific T cells after lymphodepletion with dose-dense temozolomide was well tolerated. But apparently CMV seropositivity does not guarantee tumor susceptibility to CMV-specific T cells, suggesting heterogeneity in CMV antigen expression. Moreover, effector function of these T cells was attenuated, indicating a requirement for further T-cell modulation to prevent their dysfunction before conducting large-scale clinical studies.

Peripheral nervous system damage from hematologic malignancies is related to neoplastic cells infiltration of peripheral nerves or to monoclonal antibody production cross-reacting with peripheral nerves' antigens. Neurolymphomatosis (NL), a rare manifestation of hematologic malignancies, occurs when malignant cells invade the peripheral nerves leading to various manifestations. Here, we report a case of NL with 2 hematologic malignancies in a 79-year-old woman presenting with lower extremity pain/weakness. Investigation revealed anemia, IgM kappa monoclonal gammopathy, and elevated anti-MAG titer. Electrodiagnostic studies were consistent with mononeuropathy multiplex while imaging suggested malignancy in her ovaries and right S1 nerve root. Bone marrow and ovarian biopsies revealed chronic myelomonocytic leukemia, Waldenstrom macroglobulinemia, and diffuse large B-cell lymphoma. She received standard chemotherapy resulting in radiographic resolution of disease and symptomatic relief. NL can precede the diagnosis of hematologic malignancy but its symptoms are not easily identifiable, whereas management depends on the treatment of the underlying tumor.

Current standard-of-care for glioblastoma (GBM) includes surgery followed by concurrent therapy with radiation and temozolomide (TMZ) followed by adjuvant TMZ. Almost all GBM patients experience recurrent/progressive disease despite upfront standard-of-care treatment, with a median survival of 3-9 months after recurrence. Unmethylated promoter for O6-methylguanine-DNA-methyltransferase (MGMT) is a validated biomarker for TMZ-resistance and is correlated with poor patient prognosis. VAL-083 is a bi-functional DNA-targeting agent which rapidly induces interstrand DNA cross-links at N7-guanine inducing double-strand breaks causing cell death and acts independently of MGMT DNA repair. This trial is an open-label two-arm biomarker-driven phase 2 clinical trial in MGMT-unmethylated, bevacizumab-naïve GBM patients with either recurrent (Group 1) or newly diagnosed GBM requiring adjuvant therapy after chemo-irradiation with temozolomide (Group 2). Patients receive VAL-083 IV at 30 or 40 mg/m2/d on days 1, 2, and 3 of a 21-day cycle. The primary objective of this study is to determine the effect of VAL-083 on median overall survival (mOS) in MGMT-unmethylated recurrent GBM patients (Group 1); and progression-free survival (PFS) in newly diagnosed GBM patients requiring adjuvant therapy after chemo-irradiation with temozolomide (Group 2), compared to historical controls in both groups. Tumor response is assessed by MRI every 42 days, using RANO criteria. The initial starting dose in this study was 40 mg/m2/d on days 1, 2, and 3 of a 21-day cycle, which was subsequently reduced to 30 mg/m2/d to improve tolerance due to myelosuppression. As of May 2021, Group 1 (Recurrent GBM) is fully enrolled: 35 evaluable patients have received 40 mg/m2/d and 48 evaluable patients have received 30 mg/m2/d VAL-083. In the adjuvant setting (Group 2), 35 evaluable patients have been enrolled (30 mg/m2/day). Enrollment, safety data and efficacy updates will be presented at the meeting. Clinicaltrials.gov identifier: NCT02717962.

BACKGROUND Patients with high-grade gliomas (HGG) often receive anti-angiogenic therapy with bevacizumab to slow disease progression and/or palliate neurological symptoms. Bevacizumab has been associated with an increased risk of two major vascular complications: venous thromboembolism (VTE) and intracranial hemorrhage (ICH). We sought to identify clinical, pathologic, and radiographic variables correlated with risk of either event occurring in patients with HGG receiving bevacizumab. METHODS We retrospectively identified 94 patients with HGG who received bevacizumab at our center from 2015-2021. Variables included demographics, performance status, IDH, MGMT, vascular risk factors, baseline anti-coagulant/anti-platelet use, concurrent chemotherapy, and presence of macrobleeds on MRI (>1 cm3 susceptibility) at the time of bevacizumab initiation. We conducted competing risk analysis using subdistribution hazard models with death as competing risk for ICH or VTE. The effects of covariates on the incidence of hemorrhage or VTE were evaluated in univariate and multivariate settings. RESULTS Of 94 patients, 36 (38.3%) and 27 (28.7%) developed VTE and ICH, respectively. 31 (33%) did not develop either. ICH and VTE events occurred after a mean of 4.46 and 5.94 cycles of bevacizumab, respectively. 20 had baseline anti-platelet/anticoagulant use, and 16 had prior VTEs. Patients with macrobleeds on MRI had a larger HR of developing acute hemorrhage [HR=2.368 (1.112, 5.043), p=0.0254]. Patients older than 50 trended toward larger HR of developing VTE in univariate analysis that approached significance [HR=1.799 (0.889, 3.637), p=0.1023]. Sex, performance status, IDH, MGMT, vascular risk factors, baseline anticoagulant/anti-platelet use and concurrent chemotherapy were not significantly associated with occurrence of VTE. CONCLUSIONS The presence of macrobleeds on MRI is associated with increased risk of developing acute ICH while on bevacizumab. Older age at diagnosis of HGG may be associated with an increased risk of VTE in patients receiving bevacizumab. Larger studies are needed to confirm these findings.

BACKGROUND Checkpoint inhibitor therapy has demonstrated overall limited efficacy in the treatment of GBM. Mechanisms of resistance to checkpoint blockade need to be better elucidated. Analysis of the tumor microenvironment is critical to identify correlates of response to immune checkpoint blockade. 60 newly diagnosed GBM patients unselected for MGMT status underwent treatment with concurrent atezolizumab with radiation therapy and TMZ followed by adjuvant atezolizumab and TMZ (NCT03174197). Clinical data has been reported previously. METHODS Tissue image immunoprofiling was conducted using 2 multiplex immunofluorescence (mIF) panels against; CD3, CD8, PD-1, PD-L1, Granzyme B, FOXP3, CD45RO, CD68, and GFAP antibodies. PDL-1 (Clone SP263) malignant cells expression was assessed by immunohistochemistry. Correlations between mIF biomarkers co-expressions, IHC PD-L1, and clinical outcome including OS, radiographic response, and PFS were evaluated. RESULTS Of 60 patients enrolled, image immunoprofiling was performed successfully on pre-treatment tissue in 48 patients. 20 of 60 patients underwent re-resection for suspected recurrent disease of which 10 patients had immunoprofiling performed successfully on pre and post treatment samples. An analysis of CD3CD8+ cytotoxic T lymphocytes was consistent with prior work, showing no or relatively low levels at baseline, and no association with clinical outcome. PDL-1 expression by IHC, at thresholds of >1% or >5%, was not associated with clinical outcome. Tumors with a higher number of GFAP-expressing cancer cells had a significantly lower tumor response (p< 0.05) and median OS (430 vs. 799 days, p< 0.01). CONCLUSIONS For newly diagnosed GBM patients treated with standard of care radiation and temozolomide in combination with atezolizumab, T-cell levels and PDL-1 expression were not predictive of outcome. GFAP may represent a novel predictive biomarker of overall survival. Ongoing studies to evaluate the gut microbiome and tumor genomic (WES, CNA) and transcriptomic (RNAseq) features of these and matched tumors are underway.

The brain tumor immune microenvironment (TIME) continuously evolves during glioma progression, but a comprehensive characterization of the glioma-centric immune cell repertoire beyond a priori cell states is uncharted. In this study, we performed single-cell RNA-sequencing (scRNA-seq) and single cell- Assay for Transposase-Accessible Chromatin using sequencing (sc-ATAC-seq) on ~100,000 tumor-associated immune cells from seventeen isocitrate dehydrogenase (IDH) mutation classified primary and recurrent human gliomas and non-glioma brains (NGBs). Our analyses revealed sixty-two transcriptionally distinct myeloid and lymphoid cell states within and across glioma subtypes and we noted microglial attrition with increasing disease severity concomitant with invading monocyte-derived cells and lymphocytes. Specifically, certain microglial and monocyte-derived subpopulations were associated with antigen presentation gene modules, akin to cross-presenting dendritic cells (DCs). We identified cytotoxic T cells with poly-functional cytolytic states mostly in recurrent IDH-wt gliomas. Furthermore, ligand-receptor interactome analyses showed a preponderance of antigen presentation and phagocytosis over the checkpoint axis in IDH-wt compared to IDH-mut gliomas. Additionally, our sc-ATAC-seq analyses revealed differences in regulatory networks in NGBs, IDH-mut and IDH-wt glioma associated immune cells. In particular, we noted abundant usage of inflammatory transcription factors (TFs) as exemplified by Nuclear factor kappa B and Activator Protein-1 TF family in IDH-wt microglia when compared with microglia from IDH-mut and NGBs. Unique features such as amplification of 11- Zinc Finger Protein accessibility were restricted to monocyte derived cells and were not observed in microglia. Finally, sc-ATAC-seq profiles of CD8+ exhausted T cells from IDH-wt showed strong enhancer accessibility on Cytotoxic T-lymphocyte-associated protein 4, Layilin and Hepatitis A Virus Cellular Receptor 2 but no enrichment on PDCD1 (gene encoding Programmed cell death protein 1) was seen. In summary, our study provides unprecedented granular detail of transcriptionally defined glioma- specific immune contexture that can be exploited for immunotherapy applications. This study in K.B. laboratory was supported by the generous philanthropic contributions to The University of Texas (UT) MD Anderson Cancer Center (MDACC) Moon Shots Program™, Marnie Rose Foundation, NIH grants: R21 CA222992 and R01CA225963. This study was partly supported by the UT MDACC start-up research fund to L.W. and CPRIT Single Core grant RP180684 to N. E. N.

BACKGROUND The role of adjuvant radiation after gross total resection (GTR) for grade II meningioma is evolving, prompting further evaluation in NRG-BN003, a phase 3 national trial. Furthermore, the relationship between facility volume and outcomes in patients with grade II meningioma after GTR has not been examined at a national level. We aim to assess overall survival (OS) of patients with grade II meningioma after GTR by surgical case volume and OS by receipt of adjuvant radiation. METHODS We used the National Cancer Database to identity 2823 patients diagnosed with grade II meningioma who underwent GTR. Propensity score matching was applied to balance covariates in patients with grade II meningioma after GTR stratified by adjuvant radiation status. Multivariable logistic regression was used to assess factors associated with radiation receipt. Kaplan-Meier and log-rank tests were used to assess OS by facility volume. RESULTS As facility volume increased, OS increased, with a 5-year OS of 72.8% for facilities with GTR grade II meningioma volumes of ≤8 cases per decade and 87.5% for >8 cases per decade (P < 0.0001). There was no difference in 5-year OS between GTR alone and GTR with adjuvant radiation (84.8% vs. 86.4%; P = 0.151). Covariates significantly associated with radiation receipt included facility location, facility volume, distance, and tumor size. CONCLUSIONS Treatment at higher surgical case volume facilities is associated with improved OS for GTR grade II meningioma. These facilities also have more patients receiving adjuvant radiation. However, we observed no difference in OS between adjuvant radiation and surgery alone.

Craniopharyngioma is a rare tumor in adults. Although histologically benign, it can be locally aggressive and may require additional therapeutic modalities to surgical resection. Analyses including next generation sequencing, chromogenic and in situ hybridization, immunohistochemistry, and gene amplification were used to profile craniopharyngiomas (n=6) for frequently altered therapeutic targets. Four of six patients had the BRAFV600E missense mutation, frequent in the papillary craniopharyngioma subtype. One patient had a missense mutation in the WNT pathway, specifically CTNNB1, often associated with the adamantinomatous subtype. Craniopharyngiomas lacked microsatellite instability, had low tumor mutational burden, but did express PD-L1 protein, indicating potential therapeutic value for immune checkpoint inhibition. We identified mutations not previously described, including an E318K missense mutation in the MITF gene, an R1407 frameshift in the SETD2 gene of the PIK3CA pathway, R462H in the NF2 gene, and a I463V mutation in TSC2. Two patients testing positive for EGFR expression were negative for the EGFRvIII variant. Herein, we identified several alterations such as those in BRAFV600E and PD-L1, which may be considered as targets for combination therapy of residual craniopharygiomas.

Purpose of review Checkpoint inhibitors (CPIs) represent the forefront of novel immunotherapeutic approaches for the treatment of solid cancers. However, the clinical development of CPIs in glioblastoma (GBM) has been challenging owing to an immunosuppressive tumor microenvironment and, possibly, low tumor mutation burden. Here, we review possible mechanisms responsible for the success of programmed cell death-1 (PD-1) blockade in patients with hypermutated GBM, recent clinical trials of anti-PD-1 monotherapy, trials incorporating neoadjuvant strategies, and trials of immunotherapy combination approaches in GBM. Mechanisms of resistance to immunotherapy and methods to overcome these challenges are also discussed. Recent findings Although two large phase III trials failed to demonstrate the superior efficacy of CPI in comparison with the standard of care in newly diagnosed and recurrent GBM, recent studies suggest that opportunities exist in some patients with GBM. A phase II study showed longer survival in patients with recurrent GBM who received neoadjuvant anti-PD-1 therapy than in those who received it as adjuvant therapy. In addition, cases of response to anti-PD-1 therapy in GBM patients with clonal hypermutator tumors have been reported. Summary Even though anti-PD-1 therapy does not seem to provide a benefit for molecularly unselected GBM patients, the success of PD-1 blockade in certain subsets of patients is encouraging.

Craniopharyngioma is a rare tumor in adults. Although histologically benign, it can be locally aggressive and may require additional therapeutic modalities to surgical resection. Analyses including next generation sequencing, chromogenic and in situ hybridization, immunohistochemistry, and gene amplification were used to profile craniopharyngiomas (n=6) for frequently altered therapeutic targets. Four of six patients had the BRAFV600E missense mutation, frequent in the papillary craniopharyngioma subtype. One patient had a missense mutation in the WNT pathway, specifically CTNNB1, often associated with the adamantinomatous subtype. Craniopharyngiomas lacked microsatellite instability, had low tumor mutational burden, but did express PD-L1 protein, indicating potential therapeutic value for immune checkpoint inhibition. We identified mutations not previously described, including an E318K missense mutation in the MITF gene, an R1407 frameshift in the SETD2 gene of the PIK3CA pathway, R462H in the NF2 gene, and a I463V mutation in TSC2. Two patients testing positive for EGFR expression were negative for the EGFRvIII variant. Herein, we identified several alterations such as those in BRAFV600E and PD-L1, which may be considered as targets for combination therapy of residual craniopharygiomas

2520 Background: Pembrolizumab (Pembro), anti-PD1 therapy, is FDA approved for refractory microsatellite instability high (MSI-H)/deficient mismatch repair (dMMR) advanced/metastatic solid tumors. The robust activity of anti-PD1 therapy in these tumors argues for a neoadjuvant organ-sparing approach. However, the role of anti-PD1 monotherapy in the neoadjuvant setting is unknown. Methods: This is a phase 2 open-label, single center trial (NCT04082572) of MSI-H/dMMR non-metastatic solid tumors with localized unresectable or high risk resectable (defined as ≥ 20% recurrence) with measurable disease per RECISTv1.1 and ECOG PS 0/1. Treatment is Pembro 200mg every 3 wks for 8 cycles (6 months) followed by surgical resection with option to continue therapy for 18 cycles (12 months) followed by observation. First restaging is at 6 wks and includes baseline and 3-week 70-gene ctDNA assessment. To continue on study, patients are required to have PR/CR, SD with tumor shrinkage or SD with decline in ctDNA [highest variant allele frequency (VAF) baseline mutation]. The co-primary endpoints are safety and pathological complete response (pCR). Key secondary endpoints are response rate and organ-sparing at one year for patients who declined surgery. Results: Between 12/2019 and 2/2021, 32 pts were enrolled and treated. Enrolment goal of 35 anticipated to be met by 4/2021. Baseline characteristics included 13 females, median age of 63 yrs (range 26 - 91), Lynch syndrome in 12 pts, BRAF V600E mutation in 11 pts. Tumor type included 24 CRC and 8 non-CRC (1 endometrial, 1 gastric, 1 meningeal, 2 duodenal, 1 ampullary, 2 pancreatic). At baseline disease was resectable in 23 (72%). Among 30 evaluable pts, best overall response rate was 77%: 30% CR (n = 9), 47% PR (n = 14), 20% SD (n = 6), 3% PD (n = 1). Only one pt progressed after initial SD of -18%. Median follow-up is 6.1 months (range 0.1 - 14). Among the 6 (20%) pts who underwent surgery, pCR was seen in 3 (50%). A non-operative approach (pembro for 12 months) has been chosen in 15 pts and 1-year organ-sparing was seen in 2/2 evaluable pts. Treatment-related grade 3/4 immune adverse events (TRAE) were seen in 3 (9%) pts: grade 3 immune hepatitis (2) and grade 3 type 1 diabetes (1). Baseline ctDNA was positive in 17 (53%) pts with a median of 4 mutations per pt (1 - 35) and median highest VAF of 0.9% (range 0.3% to 38.2%). Among 26 pts with successful tumor tissue testing, median tumor mutations were 10.5, range 1 to 21 (Oncomine 134 gene panel). ctDNA decline at 3 weeks was seen in 14/17 (82%) patients. Luminal disease was present in 24 pts with endoscopic response of: CR in 13 (54%), major response 1, pending follow-up evaluation 6, not evaluated 3, and no response in 1. Conclusions: Neoadjuvant pembrolizumab is safe with encouraging clinical activity and this data suggests that a non-operative management for dMMR/MSI-H localized solid tumors should receive further investigation. Clinical trial information: NCT04082572.

Pituitary carcinoma is an aggressive tumor characterized by metastatic spread beyond the sellar region. Symptoms can be debilitating due to hormonal excess and survival is poor. Pituitary carcinomas recur despite conventional multimodality treatments. Given the recent advances in the use of immune checkpoint inhibitors (CPIs) to treat various solid cancers, there has been interest in exploring the role of immunotherapy for treating aggressive, refractory pituitary tumors. We treated 4 patients with pituitary carcinoma with pembrolizumab as part of a phase II clinical trial. Two patients (patients 1 and 2) with functioning corticotroph pituitary carcinomas (refractory to surgery, radiotherapy and chemotherapy) had partial radiographic (60% and 32% per Immune-Related Response Evaluation Criteria In Solid Tumors, respectively) and hormonal responses. Patient 1’s response continues 42 months after initiation of pembrolizumab and his tumor tissue obtained after treatment with temozolomide demonstrated a hypermutator phenotype with MSH2 and MSH6 gene mutations. Patient 2’s tumor after exposure to temozolomide was not sampled, but prior somatic mutational testing was negative. One patient with a non-functioning corticotroph tumor (patient 3) had a best response of stable disease for 4 months. One patient with a prolactin-secreting carcinoma (patient 4) had progressive disease. The latter 2 patients’ tumors did not demonstrate a hypermutator phenotype after treatment with temozolomide. Programmed death-ligand 1 staining was negative in all tumors. We report 2 cases of corticotroph pituitary carcinoma responsive to pembrolizumab after prior exposure to alkylating agents. The role of CPIs in treating patients with pituitary carcinoma, the relationship between tumor subtype and response to immunotherapy and mechanisms of hypermutation in this orphan disease require further study.Trial registration number: NCT02721732.

The brain tumor immune microenvironment (TIME) continuously evolves during glioma progression and a comprehensive understanding of the glioma-centric immune cell repertoire beyond a priori cell types and/or states is uncharted. Consequently, we performed single-cell RNA-sequencing on ~123,000 tumor-derived immune cells from 17-pathologically stratified, IDH (isocitrate dehydrogenase)-differential primary, recurrent human gliomas, and non-glioma brains. Our analysis delineated predominant 34-myeloid cell clusters (~75%) over 28-lymphoid cell clusters (~25%) reflecting enormous heterogeneity within and across gliomas. The glioma immune diversity spanned functionally imprinted phagocytic, antigen-presenting, hypoxia, angiogenesis and, tumoricidal myeloid to classical cytotoxic lymphoid subpopulations. Specifically, IDH-mutant gliomas were enriched for brain-resident microglial subpopulations in contrast to enhanced bone barrow-derived infiltrates in IDH-wild type, especially in a recurrent setting. Microglia attrition in IDH-wild type -primary and -recurrent gliomas were concomitant with invading monocyte-derived cells with semblance to dendritic cell and macrophage/microglia like transcriptomic features. Additionally, microglial functional diversification was noted with disease severity and mostly converged to inflammatory states in IDH-wild type recurrent gliomas. Beyond dendritic cells, multiple antigen-presenting cellular states expanded with glioma severity especially in IDH-wild type primary and recurrent- gliomas. Furthermore, we noted differential microglia and dendritic cell inherent antigen presentation axis viz, osteopontin, and classical HLAs in IDH subtypes and, glioma-wide non-PD1 checkpoints associations in T cells like Galectin9 and Tim-3. As a general utility, our immune cell deconvolution approach with single-cell-matched bulk RNA sequencing data faithfully resolved 58-cell states which provides glioma specific immune reference for digital cytometry application to genomics datasets. Resultantly, we identified prognosticator immune cell-signatures from TCGA cohorts as one of many potential immune responsiveness applications of the curated signatures for basic and translational immune-genomics efforts. Thus, we not only provide an unprecedented insight of glioma TIME but also present an immune data resource that can be exploited to guide pragmatic glioma immunotherapy designs.