TMET-05. MAGMAS FACILITATES METABOLIC CHANGES INDUCED BY STRESSORS IN GLIOBLASTOMA

The dynamic nature of tumor microenvironments contributes to tumor heterogeneity generating subpopulations of cells that are resistant to treatment in glioblastoma (GBM). The high recurrent rate of GBM tumors in patients can partially be explained by the presence of glioma stem cells (GSCs), which are thought to give rise to resistant clones against chemotherapy. As solid tumors expand, cancer cells can disrupt the tumor microenviroment by disrupting the blood brain barrier. Pericytes and astrocytes detach from the vascular endothelial cells, forming leaky vessels, which leads to thrombosis and eventually necrosis. Necrosis is a hallmark signature of GBM, as oxygen and nutrient supply runs low which can be observed through contrast imaging. Cancer cells go through a phenotypic change by upregulating stemness genes and glycolytic metabolism. Cells migrate away from hypoxic and nutrient deprived regions forming pseudopalisading cells which are an indication of cells becoming more invasive and malignant. Mitochondrial protein trafficking is a tightly regulated mechanism which selectively allows specific peptides carrying a mitochondrial targeting sequence (MTS) to be transported through the TOM40 and TIM23 complexes. Magmas, a TIM23 subunit, negatively regulates DNAJC19 by inhibiting its stimulatory activity on Hsp70 in the mitochondrial matrix. The regulation of the ATPase activity on Hsp70 is critical for processing pre-cursor proteins through the TIM23 complex into the mitochondrial matrix. Our laboratory has uncovered a novel role of Magmas activity in GBM cells under serum starved conditions in vitro. Magmas is downregulated in serum starved cells which allows for an increase of mitochondrial matrix proteins, which include key subunits important for forming electron transport chain complexes. This influx of ETC proteins can explain how cells are able to reduce aerobic glycolysis and increase oxidative phosphorylation (OXPHOS), a mechanism that can be exploited for potential therapeutic treatment in patients with GBM.

STEM-28. THE ROLE OF LONP1 IN DRIVING ENHANCED PMT IN THE 'LEADING EDGE' NICHE IN GLIOBLASTOMA

Glioblastoma (GBM), a high grade brain tumor, possesses poor overall survival with less than 5% surviving past five years. Previously, the TCGA classifications for GBM have included the mesenchymal, proneural, classical and neural subtypes with their own respective expression profiles and survival. Recent omics analysis has revealed other key aspects of GBM pathology, including intratumoral heterogeneity spanning all subtypes and enhanced stemness and treatment resistance and other hallmarks of proneural mesenchymal transition (PMT) following treatment with first-line standard of care treatment with radiation therapy and temozolomide (TMZ). Invading glioma stem cells (GSC) with high Nestin and hypoxia-inducible factor 1 alpha (HIF-1α) expression have been theorized to contribute to recurrence. HIF-1α acts as a master regulator driving increased stemness, invasiveness and angiogenesis. Interestingly, HIF-1α and nuclear respiratory factor-2 both upregulate Lon peptidase 1 (LonP1) in response to increased hypoxia or reactive oxygen species (ROS) production. LonP1 has been shown to drive increased metastasis, tumor growth and epithelial-mesenchymal transition (EMT), an analog of PMT, in colon cancer, melanoma and other cancer types. In a recently elucidated GBM organoid model, we present new findings demonstrating the importance of LonP1 in driving enhanced, transient PMT near the ‘invading edge’. This includes the enhanced expression of several key drivers of PMT and phenotypic hallmarks, such as increased invasiveness, proliferation and poorer survival.

INNV-18. PROLONGED REMISSION AFTER TREATMENT WITH SINGLE-AGENT IBRUTINIB AS MAINTENANCE THERAPY FOLLOWING SALVAGE RADIATION THERAPY FOR REFRACTORY/RELAPSE PRIMARY CNS LYMPHOMA

INTRODUCTION

Primary central nervous system lymphoma (PCNSL) is a rare and aggressive disease. Standard induction therapy for PCNSL consists of a high-dose methotrexate-based (HD-MTX) regimen. For relapsed or refractory primary CNS lymphoma (r/r PCNSL), most of the non-standard treatment regimens including additional chemotherapy, stem cell transplant, or whole brain radiation therapy (WBRT) may not reach long-term remission due to intolerance of the treatment by the patients or lack of effects. Here we report a case with r/r PCNSL reached more than 50-month remission after salvage WBRT followed by single agent ibrutinib maintenance therapy. CASE REPORT: a 75-year-old female with PCNSL, experienced disease recurrence, despite undergoing multiple lines of treatment including initial HD-MTX, second-line rituximab and temozolomide, repeated HD-MTX, and a clinical trial. Because her disease was refractory to these treatment options, we decided to start WBRT as salvage therapy, which resulted in significant reduction of tumor burden. Prior studies, however, showed that r/r PCNSL patients who underwent salvage WBRT alone had a median survival of only 1-2 years. Therefore, to extend the remission after salvage WBRT, she opted to try ibrutinib, a Bruton’s tyrosine kinase inhibitor with past success in treating r/r PCNSL patients, as maintenance therapy after salvage WBRT. She tolerated well and decided to be off the treatment after 18 month-maintenance therapy. The patient has been stable clinically. She has since survived for more than 50 months after the completion of salvage WBRT plus maintenance therapy with ibrutinib.

DISCUSSION

Compared to prior reports of 11 to 16 months of median survival after salvage WBRT alone for r/r PCNSL, our case has had prolonged survival, which supports the potential positive effect of ibrutinib as maintenance therapy for r/r PCNSL after salvage WBRT

NCMP-18. NEUROLOGICAL SEQUELAE IN THE ID8 OVARIAN CANCER MOUSE MODEL: P38/JNK MAPK INHIBITION AS A POTENTIAL THERAPEUTIC FOR CANCER-RELATED COGNITIVE IMPAIRMENTS AND CHEMOTHERAPY-INDUCED PERIPHERAL NEUROPATHY

OBJECTIVES

Chemotherapy-related cognitive impairment (CRCI) and chemotherapy-induced peripheral neuropathy (CIPN) are neurological sequelae of platinum-based chemotherapy. To examine the contribution of cancer itself and additional neurological impairment with chemotherapy, we used the ID8 syngeneic ovarian cancer mouse model and assessed cognition and hyperalgesia +/- cisplatin treatment. We examined the effect of p38 and c-JUN N-terminal kinase (JNK) mitogen-activated protein kinase (MAPK) inhibition on cisplatin-induced neuronal damage.

METHODS

B6 female mice were injected with 107 ID8 cells or 0.9% saline, i.p. Mice received cisplatin (2.3 m¬¬¬g/kg/day, i.p.) or 0.9% saline (OvT+CIS, OvT+VEH, respectively) for 5d, followed by 5d of rest for two cycles. Cognition was assessed longitudinally at 69d by the open field test (OFT), novel object recognition (NOR) at 75d and 104d, and novel place recognition (NPR) at 106d post-ID8 implantation. Hyperalgesia was assessed at 113d. Primary mouse and rat hippocampal neurons were pre-treated with VX-745 or SP600125, followed by cisplatin, and neuronal morphology was assessed.

RESULTS

OvT+VEH mice had detectable abdominal tumors 90d post-implantation. At 75d, OvT+VEH and OvT+CIS had impairments in NOR, with discrimination ratios (DR)= 0.52, 0.51, respectively. OvT+VEH showed trending differences vs. OvT+CIS (DR=0.39, DR=0.62, p=0.079) on NOR on 104d, and impairments on NPR on 106d (DR=0.41, DR=0.63, p=0.03). Cisplatin decreased mechanical (p< 0.05) and cold hyperalgesia (p< 0.07, n.s.) in OvT+CIS vs. OvT+VEH. VX-745 and SP600125 pre-treatment in mouse and rat hippocampal neurons prevented cisplatin-induced dendritic branching and spine density loss (p< 0.05).

DISCUSSION

While cisplatin transiently increased anxiogenic behavior, cognitive impairments, and hyperalgesia in OvT+CIS, these deficits persisted longitudinally in OvT+VEH, suggesting ovarian cancer may evoke sensory and progressive neurocognitive deficits in the absence of chemotherapy. Future studies will address hyperalgesia and cognitive differences between healthy control and ovarian cancer mice +/- cisplatin, and whether VX-745 and SP600125 administration ameliorates CRCI/CIPN in this model.

CTIM-27. AUTOLOGOUS TUMOR LYSATE-LOADED DENDRITIC CELL VACCINATION IMPROVES SURVIVAL IN PATIENTS WITH NEWLY DIAGNOSED AND RECURRENT GLIOBLASTOMA: SURVIVAL RESULTS FROM A PHASE 3 TRIAL

BACKGROUND

Standard of care (SOC) and patient survival in glioblastoma have changed little in the past 17 years. We evaluated in a phase 3 trial whether adding an autologous tumor lysate-loaded dendritic cell vaccine (murcidencel) to SOC extends survival. Patients and

METHODS

Newly diagnosed glioblastoma patients were randomized 2:1 to either murcidencel or placebo. Under a crossover design, all patients could receive murcidencel following tumor recurrence. All parties remained blinded regarding treatments before recurrence. Patients thus received murcidencel at new diagnosis (nGBM) or at recurrence (rGBM) following crossover from placebo. The primary and secondary endpoints compare overall survival (OS) with contemporaneous, matched external controls. Four sets of analyses were conducted to ensure rigorous matching of the controls, reduce biases, and confirm the robustness of the results.

RESULTS

331 patients were enrolled. With the crossover, 89% received murcidencel. Median OS (mOS) for nGBM patients (n = 232) was 19.3 months from randomization (22.4 months from surgery) with murcidencel vs. 16.5 months from randomization in the controls (HR = 0.80, p = 0.002). Survival at 48 months from randomization was 15.7% vs. 9.9%, and at 60 months was 13% vs. 5.7%. For rGBM (n = 64), mOS was 13.2 months from relapse vs. 7.8 months in the controls (HR = 0.58, p < 0.001). Survival at 24 months post-recurrence was 20.7% vs. 9.6%, and at 30 months post-recurrence was 11.1% vs 5.1%. In nGBM patients with methylated MGMT (n = 90), mOS was 30.2 months from randomization (33 months from surgery) with murcidencel vs. 21.3 months from randomization in the controls (HR = 0.74, p = 0.027). The treatment was well tolerated, with only 5 serious adverse events deemed at least possibly related to the vaccine.

CONCLUSION

Clinically meaningful and statistically significant survival extension was seen in both nGBM and rGBM patients treated with murcidencel and SOC compared with contemporaneous, matched external controls who received SOC alone.

EXTH-50. IDENTIFYING TRIM11 AS A POTENTIAL THERAPEUTIC TARGET FOR MALIGNANT GLIOMAS

TRIM11 (tripartite motif-containing protein 11) belongs to the TRIM/RBCC (the RING B-box coiled-coil) family of E3 ubiquitin ligases. Members of this family have been implicated in development, neurodegenerative diseases, cellular response to viral infection and cancer. Glioblastoma (GBM) is an aggressive infiltrative brain tumor with poor prognosis. Our previous work demonstrated that TRIM11 is over-expressed in high-grade gliomas and promotes proliferation, invasion, migration and tumor growth, suggesting TRIM11 is a target for malignant glioma treatment. Here we reported the effect of TRIM11 on GBM progression in vivo using immunocompromised mice intracranially implanted with GBM xenografts over-expressing TRIM11. The control group mice survived longer than the mice bearing TRIM11 over-expressing xenografts (P< 0.5), suggesting TRIM11 enhances tumor progression in vivo. The oncogenic effect of TRIM11 may be related to its influence on apoptosis pathway as a robust induction of poly (ADP-ribose) polymerase (PARP) was observed in TRIM11 over-expressing GBM cells. PARP could repair DNA damage caused by UV light, radiation, and certain anticancer drugs, etc. Blocking PARP may prevent cancer cells from repairing their damaged DNA, causing them to die. Temozolomide (TMZ) is a standard-of-care chemotherapeutic agent for GBM through alkylating/methylating DNA, leading to DNA damage and death of tumor cells. TRIM11 over-expressing GBM cells were found more resistant to TMZ and showed a higher survival rate compared to parental cells, indicating that TRIM11 might be a therapeutic target for GBM. Based on homology modeling we designed and synthesized small library of TRIM11 inhibitors, and identified one compound (BT# 592) significantly inhibited the growth of GBM cells in a dose-dependent manner, implicating that TRIM11 inhibitors may serve as novel agents for malignant glioma treatment. We are in the process to develop more active compounds using SAR studies to identify hit-to-lead compounds as potential therapeutics for GBM.

Somatostatin analogues in treatment-refractory meningioma: a systematic review with meta-analysis of individual patient data

Treatment-refractory meningiomas have a dismal prognosis and limited treatment options. Meningiomas express high-densities of somatostatin receptors (SSTR), thus potentially susceptible to antitumorigenic effects of somatostatin analogues (SSA). Evidence for SSA in meningiomas is scarce, and it is unclear if published literature would either (1) support wider use of SSA, if (2) more evidence is desirable, or if (3) available evidence is sufficient to discard SSA. We addressed the need for more evidence with a systematic review and meta-analysis. We performed an individual patient data (IPD) meta-analysis. Main outcomes were toxicity, best radiological response, progression-free survival, and overall survival. We applied multivariable logistic regression models to estimate the effect of SSA on the probability of obtaining radiological disease control. The predictive performance was evaluated using area under the curve and Brier scores. We included 16 studies and compiled IPD from 8/9 of all previous cohorts. Quality of evidence was overall ranked "very low." Stable disease was reported in 58% of patients as best radiological response. Per 100 mg increase in total SSA dosage, the odds ratios for obtaining radiological disease control was 1.42 (1.11 to 1.81, P = 0.005) and 1.44 (1.00 to 2.08, P = 0.05) for patients treated with SSA as monodrug therapy vs SSA in combination with everolimus, respectively. Low quality of evidence impeded exact quantification of treatment efficacy, and the association between response and treatment may represent reverse causality. Yet, the SSA treatment was well tolerated, and beneficial effect cannot be disqualified. A prospective trial without bias from inconsistent study designs is warranted to assess SSA therapy for well-defined meningioma subgroups.

BSCI-03 THE ROLE OF LONP1 IN DRIVING ENHANCED PMT IN THE ‘LEADING EDGE’ NICHE IN GLIOBLASTOMA

Glioblastoma (GBM), a high grade brain tumor, possesses poor overall survival with less than 5% surviving past five years. Previously, the TCGA classifications for GBM have included the mesenchymal, proneural, classical and neural subtypes with their own respective expression profiles and survival. Recent omics analysis has revealed other key aspects of GBM pathology, including intratumoral heterogeneity spanning all subtypes and enhanced stemness and treatment resistance and other hallmarks of proneural mesenchymal transition (PMT) following treatment with first-line standard of care treatment with radiation therapy and temozolomide (TMZ). Invading glioma stem cells (GSC) with high Nestin and hypoxia-inducible factor 1 alpha (HIF-1α) expression have been theorized to contribute to recurrence. HIF-1α acts as a master regulator driving increased stemness, invasiveness and angiogenesis. Interestingly, HIF-1α and nuclear respiratory factor-2 both upregulate Lon peptidase 1 (LonP1) in response to increased hypoxia or reactive oxygen species (ROS) production. LonP1 has been shown to drive increased metastasis, tumor growth and epithelial-mesenchymal transition (EMT), an analog of PMT, in colon cancer, melanoma and other cancer types. In a recently elucidated GBM organoid model, we present new findings demonstrating the importance of LonP1 in driving enhanced, transient PMT near the ‘invading edge’. This includes the enhanced expression of several key drivers of PMT and phenotypic hallmarks, such as increased invasiveness, proliferation and poorer survival.

Successful Consolidation/Maintenance Therapy with Single Agent Ibrutinib for Primary CNS Lymphoma after Initial Induction Therapy

Primary central nervous system lymphoma (PCNSL) is a rare and aggressive disease that originates from lymphocytes and develops in the central nervous system. There is no standard consolidation/maintenance therapy for PCNSL. While there exists a variety of options, the high chance of inferior outcomes for elderly patients and the risk of neurotoxicity requires exploration of alternative options for consolidation/maintenance therapy for PCNSL in the elderly population with CNS lymphoma. We treated one 77-year-old patient with single agent ibrutinib, a Bruton’s tyrosine kinase inhibitor that crosses the blood-brain-barrier, as consolidation/maintenance therapy after induction therapy with high-dose methotrexate (HD-MTX) and rituximab plus temozolomide. This treatment resulted in good tolerance, further resolution of a small residue lymphoma, and sustained remission. The patient has completed one year of consolidation/maintenance therapy and is currently under clinical and imaging surveillance. She has survived 27 months without recurrence since diagnosis. This case shows the potential effectiveness of single agent ibrutinib as consolidation/maintenance therapy for PCNSL after induction therapy. More cases are needed to confirm the findings.

Altered Retrograde Signaling Patterns in Breast Cancer Cells Cybrids with H and J Mitochondrial DNA Haplogroups

The aim of this study was to determine the role of retrograde signaling (mitochondria to nucleus) in MCF7 breast cancer cells. Therefore, in the present study, MCF7-H and MCF7-J cybrids were produced using the mitochondria from the same H and J individuals that were already used in our non-diseased retinal pigment epithelium (ARPE19) cybrids. MCF7 cybrids were treated with cisplatin and analyzed for cell viability, mitochondrial membrane potential, ROS, and expression levels of genes associated with the cGAS-STING and cancer-related pathways. Results showed that unlike the ARPE19-H and ARPE19-J cybrids, the untreated MCF7-H and MCF7-J cybrids had similar levels of ATP, lactate, and OCR: ECAR ratios. After cisplatin treatment, MCF7-H and MCF7-J cybrids showed similar (a) decreases in cell viability and ROS levels; (b) upregulation of ABCC1, BRCA1 and CDKN1A/P21; and (c) downregulation of EGFR. Cisplatin-treated ARPE19-H and ARPE19-J cybrids showed increased expression of six cGAS-STING pathway genes, while two were increased for MCF7-J cybrids. In summary, the ARPE19-H and ARPE19-J cybrids behave differentially from each other with or without cisplatin. In contrast, the MCF7-H and MCF7-J cybrids had identical metabolic/bioenergetic profiles and cisplatin responses. Our findings suggest that cancer cell nuclei might have a diminished ability to respond to the modulating signaling of the mtDNA that occurs via the cGAS-STING pathway.

MODL-09. Exploring the role of Magmas (mitochondria-associated protein involved in granulocyte-macrophage colony-stimulating factor signal transduction) inhibition as a potential therapeutic intervention in medulloblastoma

BACKGROUND: Brain tumors are the second most common type of pediatric cancer and the leading cause of all cancer-related deaths in children. Medulloblastoma (MB) is the most common type of malignant pediatric brain tumor and has a five-year overall survival ranging from 40-75%, depending on the patient’s age and other prognostic features. There are various anti-cancer therapies against medulloblastoma, but the treatment of recurrent and refractory disease remains a challenge. As a result, the need for new and novel therapies remain a top priority. One area of interest in CNS tumors are targets within mitochondria. Magmas overexpression has been reported in multiple types of metabolically active tissue and cancer cells, including prostate cancer, pituitary adenoma, and glioma. Some new data suggest that specific subgroups of medulloblastoma may also overexpress Magmas. This ongoing study aims to examine whether Magmas inhibition by compound “BT9” could be beneficial in the treatment of medulloblastoma. METHODS: We continue to study the ability of a Magmas inhibitor (BT#9) as a therapeutic agent in stable medulloblastoma cell lines and patient-derived primary cultures by performing MTT assays, tunnel assays, flow cytometry, migration assays, and invasion assays. RESULTS: Similar to the adult GBM studies, Magmas inhibition by BT#9 had significant cytotoxic effects, causing both decreased cell proliferation, increased apoptosis, and blocked cell migration in medulloblastoma cell lines DAOY, D283, and D425. IC50s determined for each during different time points demonstrated an average range 2-5μM compared to the average range seen in adult glioblastoma cell cultures which could range up to 10 μM. These findings suggest that the inhibition of Magmas could potentially optimize clinical outcomes in recurrent/refractory medulloblastoma and warrants further investigation. Our future studies will include the determination of IC50s for primary cell cultures and in vitro testing with patient-derived xenograft models.

DDRE-38. MAGMAS INHIBITION IN MEDULLOBLASTOMA CELL CULTURES AND PATIENT-DERIVED XENOGRAFT MODELS: POTENTIAL THERAPEUTIC IMPLICATIONS

BACKGROUND

Brain tumors are the second most common type of pediatric cancer and are the leading cause of all cancer-related deaths in children. Medulloblastoma (MB) is the most common type of malignant pediatric brain tumor and has a five-year overall survival ranging from 40-75%, depending on the patient’s age and other prognostic features. There are current anti-cancer therapies against medulloblastoma, but the treatment of recurrent disease remains a challenge. Magmas (mitochondria-associated protein involved in granulocyte-macrophage colony-stimulating factor signal transduction) overexpression has been reported in multiple types of metabolically active tissue and cancer cells, including prostate cancer, pituitary adenoma, and glioma. Limited data suggest that specific subgroups of medulloblastoma may also overexpress Magmas. This study aims to examine whether Magmas inhibition by compound “BT#9” could be beneficial for the treatment of medulloblastoma.

METHODS

We studied the ability of a Magmas inhibitor (BT#9) as a therapeutic agent in stable medulloblastoma cell lines (DAOY and D283) and patient-derived primary cultures with MTT assays, migration assays, and invasion assays.

RESULTS

Similar to the adult GBM studies, Magmas inhibition by BT9 had significant cytotoxic effects, causing both decreased cell proliferation and blocked cell migration in medulloblastoma cell lines DAOY and D283. IC50s determined for each during different time points demonstrated an average range of less than 3μM compared to the average range seen in adult glioblastoma cell cultures (< 10 μM). These findings suggest that the inhibition of Magmas warrants further investigation as a potential therapeutic target to optimize clinical outcomes in medulloblastoma. Our future studies will include the determination of IC50s for primary cell cultures and in vitro testing with patient-derived xenograft models.

INNV-29. BILATERAL PARIETAL LYMPHOMA LESIONS RESPONDED DIFFERENTLY TO HD-MTX AND RITUXIMAB/TEMOZOLOMIDE THERAPY

INTRODUCTION

Primary CNS lymphoma is a rare aggressive hematological malignancy. Current chemotherapy for induction phase is HD-MTX single agent or HD-MTX based combination regimen. We report a rare case whose left and right parietal lymphoma lesions in the brain responded to different induction therapy regimens during the induction phase.

CASE REPORT

A 43-year-old female presented with seizure and her brain MRI showed bilateral parietal brain lesions in January of 2020. Biopsy and work-up revealed primary CNS diffuse large B-cell lymphoma (DLBCL). The patient underwent HD-MTX therapy. Brain MRI showed clear progression of left parietal lymphoma but stable right parietal lymphoma after two cycles of HD-MTX at 8 g/m2. The treatment was switched to a rituximab 750 mg/m2 weekly and temozolomide 150 mg/m2 daily one-week-on and one-week-off regimen. After 8 weeks, her brain MRI showed nearly complete response of her left parietal lymphoma to rituximab/temozolomide but progression of her right parietal lymphoma. She was switched back to HD-MTX and completed total 8 cycles. Her right parietal lymphoma lesion showed complete response to HD-MTX. The patient is doing well and has been off the treatment over the past 10 months and is waiting for consolidation therapy with autologous stem cell transplantation that has been postponed due to the COVID pandemic.

DISCUSSION

Our case highlights the very rare heterogenous feature of primary CNS lymphoma responding to different treatment regimen. Biopsy of bilateral heterogeneous lesions may be indicated to compare the different molecular features of the lymphoma to find underlying mechanism if they respond to treatment differently. Specific treatment regimen should be selected based on the responsiveness of CNS lymphoma lesions or combination therapy is selected to cover the heterogeneous susceptibility to chemotherapy regimens.

NCMP-13. ID8 OVARIAN CANCER MOUSE MODEL MIMICS NEUROLOGICAL SEQUELAE OF OVARIAN CANCER IN WOMEN

OBJECTIVES

Chemotherapy-related cognitive impairment (CRCI) and chemotherapy-induced peripheral neuropathy (CIPN) are neurological complications of cancer treatment. Cisplatin is used to treat ovarian malignancies, and over 70% of women experience CRCI/CIPN during and after platinum-based chemoTx. However, over 30% of non-CNS cancer patients experience cognitive impairment prior to chemoTx. To examine the contribution of cancer itself and additional neurological impairment with chemoTx, we used an ID8 syngeneic mouse model of ovarian cancer and assessed hyperalgesia and cognition +/- cisplatin treatment.

METHODS

C57BL/6 female mice were injected intraperitoneally with 107 ID8 ovarian cancer cells or 0.9% saline. After 10d of ID8 injections, mice received cisplatin (2.3 mg/kg/day, i.p.) or 0.9% saline (OvT+CIS, OvT+VEH, respectively) for 5d, followed by 5d of rest for 2 cycles. Mechanical and cold hyperalgesia were assessed longitudinally. Cognition was assessed 28d post-chemoTx by the open field test (OFT), novel object recognition (NOR), and novel place recognition (NPR) tasks.

RESULTS

OvT+VEH and OvT+CIS mice developed an increased sensitivity to mechanical ( >200%, p< 0.001) and thermal (cold) stimuli ( >78%, p< 0.004) starting 14d post-ID8 implantation, vs non-tumor controls (CON). In the OFT, OvT+CIS mice had increased anxiogenic behavior (55%, p< 0.001) vs CON, and (46%, p< 0.05) vs OvT+VEH. In NPR, OvT+CIS had reduced discrimination (37%, p< 0.05) vs CON. OvT+VEH and OvT+CIS showed impaired discrimination (25%, p< 0.05 & 33%, p< 0.01, respectively) in NOR vs CON, with trending differences between OvT+CIS vs OvT+VEH in hyperalgesia and cognitive tasks. DISCUSSION: This is the first rodent model to demonstrate that ovarian cancer may evoke sensory and neurocognitive changes in the absence of chemotherapy. Future development of the model will address hyperalgesia and cognitive differences between OvT+VEH vs OvT+CIS. This model has potential for translational studies on the treatment of neurological sequelae of cancer and cisplatin-induced CRCI and CIPN.

DDRE-31. MITOCHONDRIAL TRAFFICKING AS A TARGET FOR GBM THERAPY

Glioblastoma (WHO Grade IV glioma) is the most aggressive brain cancer. The current standard of care treatment includes surgery, radiation, and chemotherapy. Tumor recurrence is almost inevitable as less than 50% of patients survive more than two years. The low survival rate poses a dire need to develop an effective therapy for GBM patients. GBM cells are resistant to treatment, as they activate their DNA damage response mechanisms to overcome the effects of radiation and temozolomide (TMZ) treatments. Recurrent tumors can arise from slow cycling and self-renewing stem/tumor-initiating cells resistant to radiation and TMZ. No second-line therapy was proven to prolong survival after TMZ failure. Magmas (Mitochondria-associated protein involved in granulocyte-macrophage colony-stimulating factor signal transduction) is a subunit of the TIM23 complex regulating precursor protein trafficking into the mitochondrial matrix. Magmas is encoded by pam16, known to be upregulated in human pituitary adenomas, prostate cancer and GBM. Previous studies have demonstrated that Magmas negatively regulates the stimulatory activity of Pam18, which in turn stimulates the ATPase activity of mitochondrial heat shock protein 70 (mtHsp70). No small molecules targeting Magmas are in clinical use. We developed a novel small molecule inhibitor (BT9) that has been specifically designed to inhibit Magmas binding to Pam18. BT9 induces apoptosis through cleavage of caspase-3, reduced mitochondrial respiration and glycolysis. Our recent findings also demonstrate that BT9 treatment reduced protein trafficking of Lon protease into the mitochondrial matrix. Pretreatment of glioma cells with BT9 sensitizes cells to radiation treatment and enhances the TMZ activity. BT9 can cross the blood-brain-barrier and improve survival in intracranial glioma PDX models. BT9 has potential therapeutic value by directly dysregulating mitochondrial function in GBM, enhancing radiation and chemotherapy response, and improving survival in a relevant animal model.

CTNI-53. RADIATION TREATMENT VOLUMES BEFORE AND AFTER BRAF/MEK THERAPY IN NEWLY DIAGNOSED PAPILLARY CRANIOPHARYNGIOMAS: A CORRELATIVE ANALYSIS OF THE ALLIANCE A071601 PHASE II TRIAL

PURPOSE

Standard of care for craniopharyngiomas is surgery with or without radiotherapy (RT). Cohort A of Alliance A071601 evaluated the efficacy of BRAF/MEK inhibition with vemurafenib/cobimetinib in patients with previously untreated papillary craniopharyngiomas (PCP), which carry the BRAF V600E mutation. Cohort B is currently enrolling patients with recurrence after RT. In a correlative analysis, we examined changes in RT volumes after BRAF/MEK therapy in Cohort A.

METHODS

Previously unirradiated patients with BRAF-mutated PCP were treated with vemurafenib/cobimetinib. Sixteen patients had scans available before starting vemurafenib/cobimetinib (“pre-therapy”) and after completing therapy (“post-therapy”). Two patients went off study treatment after 8 and 9 days due to side-effects and were excluded for this analysis. Gross target volumes (GTV) were contoured on pre-therapy and post-therapy scans. On post-therapy scans, an additional target comprising gross disease and at-risk regions for microscopic residual disease (GTV-micro) was defined and considered the treatment volume. Clinical target volume (CTV) was a 5-mm uniform expansion on pre-therapy GTV and post-therapy GTV-micro. Volumes were independently reviewed by two radiation oncologists. Changes in volumes from pre- versus post-therapy were compared using the Wilcoxon signed rank test.

RESULTS

In 14 patients evaluated, 57% were female and median age at enrollment was 49.5 years (range 33-83). Median time on treatment was 8.9 months (range 4.0-18.0). Median GTV pre-therapy was 3.8 mL (range 0.2-23.4) versus 0.3 mL (range 0.0-3.2) post-therapy (p=0.0001) and 1.7 mL (range 0.1-8.0) post-therapy GTV-micro (p=0.0001). Median CTV pre-therapy was 13.7 mL (range 2.8-51.8) versus 9.1 mL (range 2.2-27.5) post-therapy (p=0.0001). All tumors abutted the optic chiasm pre-therapy, only 6 did post-therapy.

CONCLUSIONS

Vemurafenib/cobimetinib resulted in smaller RT volumes. BRAF/MEK inhibitors could reduce RT volumes and spare dose to surrounding normal structures. Enrollment to Cohort B of Alliance A071601 should be considered for patients with recurrent tumors after RT.

SUPPORT

https://acknowledgments.alliancefound.org

IMMU-27. LONG TERM STABILIZATION OF RECURRENT HIGH-GRADE GLIOMA WITH PD-1 INHIBITOR PEMBROLIZUMAB IN TWO CASES

INTRODUCTION

Despite PD-1 inhibition having success in many cancers, it has uncertain effects in brain tumors. We report two cases of recurrent high-grade gliomas that have remained stable for over one year since starting pembrolizumab.

CASE REPORTS

Case 1: A 59-year-old male was diagnosed with glioblastoma (GBM) without MGMT methylation or IDH mutation in late 2018 after surgery. He received radiation and temozolomide (TMZ) followed by adjuvant TMZ before tumor progression. He underwent second tumor debulking with recurrent GBM on pathology with negative PD-L1 expression. He started carboplatin. Progression was noticed after 7 to 8 cycles. Pembrolizumab was added. Tumor was stabilized. Carboplatin was completed after total 12 cycles and the patient has continued single agent of pembrolizumab for more than one year with stable brain MRIs. The patient has survived for 24 months since recurrence and 30 months since diagnosis. Case 2: A 53-year-old male had a brain tumor discovered on MRI in 2012 and received no treatment until resection in 2014. In 2016, he underwent second tumor debulking and was diagnosed with anaplastic oligodendroglioma with negative PD-L1 expression. He received radiation followed by PCV regimen. 17 months since diagnosis, he had first tumor progression on PCV. TMZ was started. 22 months since diagnosis, bevacizumab was initiated due to further growth. 33 months since diagnosis, pembrolizumab was added due to new lesions after 12-months of bevacizumab therapy. His tumor was stabilized. Bevacizumab was eventually discontinued. He has continued single agent pembrolizumab for 6 months so far. His tumor has been stable for 22 months since starting pembrolizumab. Survival has been 38 months from first recurrence and 7 years since tissue diagnosis.

DISCUSSION

These cases demonstrate the potential effects of anti-PD-1 immunotherapy in stabilizing recurrent high-grade glioma with combination of other treatment agents followed by single agent as maintenance therapy.

INNV-28. POTENTIAL EFFECTIVE CONSOLIDATION THERAPY WITH SINGLE AGENT IBRUTINIB FOR A CASE WITH PRIMARY CNS LYMPHOMA AFTER INITIAL HD-MTX AND RITUXIMAB INDUCTION THERAPY

INTRODUCTION

Primary CNS Lymphoma (PCNSL) is a rare and aggressive cancer that originates from lymphocytes and develops in the central nervous system. Standard induction therapy involves high-dose methotrexate (HD-MTX)-based chemotherapy, which achieves complete or partial response in most PCNSL patients. However, there is no standard consolidation therapy. We report one case in which ibrutinib, a Bruton’s tyrosine kinase inhibitor, replaced low-dose WBRT as consolidation therapy after induction by HD-MTX and rituximab. Ibrutinib treatment yielded good tolerance and further resolution of small residue lymphoma.

CASE REPORT

The patient is a 77-year-old female who presented with slurred speech, right-sided weakness, and difficulty word-finding in early 2020. Brain MRI found multifocal lesions, and biopsy of the largest lesion near the left lateral ventricle revealed diffuse large B cell lymphoma. The patient began HD-MTX at 6 g/m2 for the first cycle of induction therapy. She continued HD-MTX every two weeks, but dosage was reduced every cycle due to worsening renal function. Ultimately, MTX was discontinued after 6 cycles. Brain MRI showed significant response after HD-MTX except for small residue lymphoma at the biopsy area. 2nd line regimen rituximab and temozolomide was given to complete induction. Brain MRI was stable, but the small enhancing residue lymphoma at left peri-ventricle area was persistent after the induction therapy (uCR). Ibrutinib as consolidation therapy began after discussion with the patient. The patient tolerated 560 mg ibrutinib for 6 cycles initially, then switched to a reduced dose of 420 mg for cycles 7 and 8 due to neutropenia. Brain MRIs have been stable with resolution of the small lymphoma residue after 6 cycles of ibrutinib. The patient continues ibrutinib for the goal of one year of consolidation therapy.

DISCUSSION

Our case highlights the potential of single-agent ibrutinib as consolidation therapy for PCNSL after HD-MTX and rituximab/temzolomide induction therapy.

CTNI-08. DB102-01 ENGAGE STUDY: A BIOMARKER-GUIDED, RANDOMIZED, DOUBLE-BLIND, PLACEBO-CONTROLLED, MULTI-CENTER PHASE 3 CLINICAL TRIAL OF DB102 IN PATIENTS WITH NEWLY DIAGNOSED GLIOBLASTOMA (GBM)

Precision medicine is vital for treating many cancers. Lack of valid biomarkers might contribute to the failure of drug therapy for GBM. The Denovo Genomic Marker 1 (DGM1), a novel pharmacogenomic biomarker, has been discovered by a genome-wide screen of patients treated with DB102 (enzastaurin) in a trial for lymphoma. Similarly, retrospective analyses showed that DB102 significantly improved outcomes in the biomarker positive GBM patients treated with DB102, regardless of MGMT promoter methylation status. The ENGAGE Study (DB102-01, NCT03776071) is a global Phase 3 clinical trial to confirm clinical benefits in patients with newly diagnosed GBM who are DGM1 biomarker positive. This is a prospective, randomized, double-blind, placebo-controlled, multi-center study. A total of 318 patients with newly diagnosed GBM will be enrolled. After screening, patients will be randomized to receive radiation therapy (RT) and temozolomide (TMZ) plus either DB102 or a matched placebo for 6 weeks in the Concurrent Phase, followed by DB102 or placebo for approximately 5 weeks in the Single-Agent Phase and then TMZ plus DB102 or placebo in the Adjuvant Phase (up to 12 cycles). Thereafter DB102 or placebo may be continued as a single agent for up to 2 years. The primary endpoint is overall survival (OS). The secondary endpoints include progression free survival (PFS), objective response rate (ORR) and drug safety. By April 2021, the safety-run-in part was completed. The study is now open for enrollment in the US and soon in Canada and China.

331 Tumor markers associated with increased survival in a phase II trial of dendritic cell/tumor-initiating-cell vaccine AV-GBM-1 in patients with newly diagnosed glioblastoma

Background

Standard aggressive therapy of glioblastoma (GBM), which includes maximum safe resection, concurrent radiation therapy and temozolomide chemotherapy (RT/TMZ) followed by maintenance TMZ, is associated with a 25% 2-year overall survival (OS). Adding treatment with AV-GBM-1, a vaccine consisting of autologous dendritic cells (DC) pulsed with autologous tumor antigens (ATA) may improve OS by inducing and/or enhancing the host anti-GBM immune response. Methylation of the O-6-methylguanine-DNA methyltransferase (MGMT) gene promoter, and mutation of the gene for isocitrate dehydrogenase (IDH) are favorable prognostic markers in newly diagnosed GBM. An objective of a multi-center phase II clinical trial was to determine whether these markers were still prognostic for OS in patients treated with adjunctive AV-GBM-1.

Methods

Key eligibility criteria for intent-to-treat (ITT) enrollment were: (1) confirmation of primary GBM, (2) successful GBM cell culture, (3) collection of sufficient numbers of monocytes (MC) by leukapheresis, (4) Karnofsky Performance Status 70 or greater after recovery from surgery, and (5) plan to treat with concurrent RT/TMZ. AV-GBM-1 was manufactured while patients were being treated with RT/TMZ. Interleukin-4 and granulocyte-macrophage colony stimulating factor (GM-CSF) were used to differentiate DC from MC. Each vaccine consisted of autologous DC incubated with ATA from the lysate of irradiated cultured GBM cells grown in serum-free media with factors that favor survival and proliferation of stem cells and early progenitor cells (tumor-initiating cells). After recovery from RT/TMZ, intent was to vaccinate for up to six months with cryopreserved AV-GBM-1 admixed with 500 mg GM-CSF. All patients had testing for MGMT-methylation and IDH-mutation. OS was calculated from date of ITT enrollment.

Results

60 patients were enrolled during August 2018 to January 2020. MGMT promoter methylation was detected in 21 (35%), mutated IDH in 7 (12%), and one or both in 25 (42%). At a minimum follow-up of 15 months, median OS had not been reached for patients with a methylated MGMT promotor, IDH mutation, or one or both, compared to 14.6 months for 38 with unmethylated MGMT promotor (p=0.026), 14.7 months for 53 with IDH wild-type (p=0.044), and 14.6 months for 35 who had neither (p=0.017). 18-month OS rates were 59% vs 35% for MGMT promotor methylation, 71% vs 40% for IDH mutation and 58% vs 32% for either.

Conclusions

Both MGMT promotor methylation and IDH mutation were associated with a substantial and similar survival benefit in primary GBM patients treated with AV-GBM-1 in addition to standard aggressive therapy.

Trial Registration

Clinicaltrials

gov NCT03400917

Ethics Approval

This study was approved by the Western IRB, approval number 20182582; all participants gave written informed consent before taking part

332 Tumor collection and establishment of tumor-initiating cell cultures as antigen source for AV-GBM-1 dendritic cell vaccines for a phase II trial in patients with newly diagnosed glioblastoma

Background

Despite standard aggressive therapy (maximum safe surgical resection, concurrent radiation therapy and temozolomide chemotherapy (RT/TMZ), then maintenance TMZ), 2-year survival is only about 25% for patients with newly diagnosed primary glioblastoma (GBM). Adding AV-GBM-1, a vaccine consisting of autologous dendritic cells (DC) pulsed with autologous tumor antigens (ATA) may improve survival. One objective of a multi-center phase II clinical trial was to determine the feasibility of collecting fresh GBM and establishing short-term cell cultures of GBM tumor-initiating cells (TIC) to serve as ATA source.

Methods

Key eligibility criteria for tumor collection were (1) clinical suspicion of new primary GBM, (2) age 18 to 70 years (3) tentative agreement to undergo a leukapheresis procedure after recovery from surgery, and (4) tentative plans for RT/TMZ. Fresh tumor was placed in media and shipped in a transport kit by overnight courier to AIVITA where a cell suspension was placed in culture and incubated in serum-free medium with factors that favor survival and proliferation of TICS (stem cells and early progenitor cells). The intent was to produce a patient-specific DC-ATA vaccine by incubating a lysate of irradiated TICs with autologous DC for subsequent subcutaneous injection.

Results

Patients were enrolled from five sites in California, one in Kentucky and one in New Jersey. Tumors were collected between August 2018 and January 2020. 106 patients consented for tumor collection, but 15 were not GBM, 4 had insufficient tissue to send, 2 patients withdrew consent, 4 were ineligible because of age, and 1 was ineligible because of autoimmune disease. Of the 80 GBM tumors that were placed into culture, 7 were discontinued because of patient withdrawal. 71/73 (97%) resulted in a successful cell culture; two were unsuccessful because of contamination. 60/71 subsequently consented for intent-to-treat ; 46/60 (77%) had cells in culture for 28 days or less, 11 were in culture for 30 to 35 days, and the remaining 3 were cultured 46, 54, and 55 days. The average number of cells per culture at the time of irradiation was 14.0 million (range 0.78 to 63.3 million). 58/60 (97%) yielded more than 1 million TICs for irradiation for the tumor cell lysate; 36/60 (60%) had more than 10 million cells irradiated. 57 patients were subsequently treated with AV-GBM-1 after recovery from RT/TMZ.

Conclusions

Self-renewing GBM TIC cultures can be reliably and rapidly established for use as the antigen source for personal DC-ATA vaccines.

Trial Registration

Clinicaltrials

gov NCT03400917

Ethics Approval

This study was approved by the Western IRB, approval number 20182582; all participants gave written informed consent before taking part

333 Changes in proteomic markers after injections of personal AV-GBM-1 dendritic cell/tumor initiating cell vaccines in a phase II trial in patients with newly diagnosed glioblastoma

Background

Despite standard aggressive therapy, including maximum safe surgical resection, concurrent radiation therapy and temozolomide chemotherapy (RT/TMZ) followed by maintenance TMZ, survival is still extremely poor for patients with newly diagnosed primary glioblastoma (GBM). Adding treatment with AV-GBM-1, a personal vaccine consisting of autologous dendritic cells (DC) pulsed with autologous tumor antigens (ATA) may improve survival. One objective of a multi-center phase II clinical trial was to determine changes in blood proteomics before and after injections of AV-GBM-1.

Methods

AV-GBM-1 consists of autologous DC incubated with ATA from a lysate of irradiated autologous GBM cells that had been placed in culture and incubated in serum-free medium with factors that favor the survival and proliferation of stem cells and early progenitor cells. After recovery from RT/TMZ, GBM patients were injected subcutaneously with AV-GBM-1 admixed in granulocyte-macrophage colony-stimulating factor (GM-CSF) at weeks 1, 2, 3, 8, 12, 16, 20, and 24. Blood samples obtained at baseline (week-0), just prior to the third injection (week-2) and just prior to the fourth injection (week-8), were cryopreserved and subsequently analyzed for 448 proteomic markers using quantitative, multiplex enzyme-linked immunosorbent assays (Raybiotech, Inc., Norcross, GA.). In this preliminary analysis the averages of paired samples for each time point were determined and compared using the student T-Test with a focus on differences of p<0.01.

Results

Patients were enrolled from five sites in California, and one each in Kentucky and New Jersey. 57 patients were treated during November 2018 to October 2020. Paired samples from all three time points were available for 49 patients. After two weekly injections there were increases in thymus-and activation-regulated chemokine (TARC, CCL17), the chemotactic protein chemerin, lipocalin-2, (expressed by macrophages and epithelium in response to inflammation) and angiopoietin-1 (suppressor of vascular inflammation), and decreases in thrombospondin-5 (possibly involved in synaptogenesis in brain repair), angiotensinogen (a precursor of all angiotensin peptides), and beta-fibroblast growth factor (important in tissue repair). The increase in TARC (p<0.0000001) was attributed to GM-CSF; TARC had declined almost to baseline levels by week-8. The other six markers had p values between 0.0011 and 0.0087. The only marker that was still changed at week-8 was thrombospondin-5 (p=0.023).

Conclusions

If there were humoral changes in proteins associated with Th1 and Th2 responses, these were no longer present after two weekly vaccinations. More sophisticated analyses of this data set, such as principal component analysis, may be needed to understand the effects of AV-GBM-1.

Trial Registration

Clinicaltrials

gov NCT03400917

Ethics Approval

This study was approved by the Western IRB, approval number 20182582; all participants gave written informed consent before taking part

952 Phase II trial of AV-GBM-1: dendritic cell vaccine pulsed with lysate enriched for autologous tumor-initiating cell antigens in the treatment of patients with newly diagnosed glioblastoma

Background

Standard therapy of glioblastoma (GBM), which includes maximum safe resection, concurrent radiation therapy and temozolomide chemotherapy (RT/TMZ) followed by maintenance TMZ, is associated with poor overall survival (OS). Adding treatment with AV-GBM-1, a vaccine consisting of autologous dendritic cells (DC) pulsed with autologous tumor antigens (ATA) may improve OS. A multi-center phase II clinical trial was conducted to determine feasibility, safety, and efficacy of AV-GBM-1.

Methods

Key eligibility criteria for tumor collection were clinical suspicion of newly diagnosed GBM and age 18 to 70 years at the time of surgery. Prior to starting RT/TMZ, key eligibility criteria for intent-to-treat-with-AV-GBM-1 enrollment were: (1) primary GBM confirmed, (2) successful GBM cell culture, (3) collection of sufficient numbers of monocytes (MC) by leukapheresis, (4) Karnofsky Performance Status 70 or greater and (5) plan to treat with concurrent RT/TMZ. AV-GBM-1 was manufactured during RT/TMZ. Interleukin-4 and granulocyte-macrophage colony stimulating factor (GM-CSF) were used to differentiate MC into DC. AV-GBM-1 consists of autologous DC incubated with ATA from the lysate of irradiated GBM cells grown in serum-free media with factors that favor the survival and proliferation of stem cells and early progenitor cells. After recovery from RT/TMZ, over six months patients received up to 8 subcutaneous injections of AV-GBM-1 admixed with 500 μg GM-CSF. The primary objective was to determine if OS was 75% or higher 14.6 months from ITT enrollment, which ended January 2020. The minimum follow-up at the time of analysis was 15.2 months. Secondary endpoints included progression-free survival (PDS) from ITT enrollment and from the first injection.

Results

Success rates for cell cultures and sufficient monocyte collections were both 97%. AV-GBM-1 was manufactured for 60/60 (100%). 57 patients received 392 injections; 68% received all 8. The primary adverse events (AE) attributed to AV-GBM-1 were local injection site reactions (16%) and flu-like symptoms (10%). Progression-free survival (PFS) from ITT enrollment is 10.3 months, about 50% longer than reported in four randomized trials with comparable standard therapy arms. PFS from the first injection is 8.3 months, which is 51% and 107% longer than reported in two randomized trials with comparable standard therapy arms. OS was 72% at 12 months, but dropped to 54% at 14.6 months; median OS is 16.0 months.

Conclusions

Patent-specific AV-GBM-1 was reliably manufactured and distributed for administration. AV-GBM-1 produced minimal toxicity. PFS was very encouraging but did not translate into OS, perhaps because of discontinuation of treatment after 8 months.

Trial Registration

[Clinicaltrials.gov NCT03400917]

Ethics Approval

Western IRB, approval number 20182582

Consent n/a

336 Adverse events in a phase II trial of AV-GBM-1: dendritic cell vaccine pulsed with lysate enriched for autologous tumor-initiating cell antigens for patients with newly diagnosed glioblastoma

Background

Standard glioblastoma (GBM) therapy includes maximum safe resection, concurrent radiation therapy and temozolomide chemotherapy (RT/TMZ), and maintenance TMZ, but it is associated with a 2-year survival of only about 25%. Adding treatment with AV-GBM-1, a vaccine consisting of autologous dendritic cells (DC) pulsed with autologous tumor antigens (ATA) may improve survival, but it may be associated with additional toxicity. One objective of a multi-center phase II clinical trial was to identify, characterize, and enumerate treatment-emergent adverse events (TEAE) and serious AE (SAE) that occurred during AV-GBM-1 treatment.

Methods

Key eligibility criteria for enrollment prior to starting RT/TMZ, were: (1) confirmation of primary GBM, (2) successful GBM cell culture, (3) collection of sufficient numbers of monocytes (MC) from leukapheresis, (4) Karnofsky Performance Status 70 or higher, and (5) planning to treat with concurrent RT/TMZ. Interleukin-4 and granulocyte-macrophage colony stimulating factor (GM-CSF) were used to differentiate DC from MC. AV-GBM-1 was manufactured while patients were being treated with RT/TMZ. Each vaccine consisted of autologous DC incubated with ATA from the lysate of irradiated GBM cells grown in serum-free media with factors that favor survival and proliferation of tumor initiating cells, i.e., tumor stem cells and early progenitor cells. Following RT/TMZ, patients were injected subcutaneously with cryopreserved AV-GBM-1 admixed with 500 μg GM-CSF at weeks 1, 2, 3, 8, 12, 16, 20 and 24. Adverse events (AE) were identified and classified per Common Terminology Criteria for Adverse Events (CTCAE v 4.03).

Results

57 patients received at least one injection of AV-GBM-1 during November 2018 to October 2020. Patients received an average of 6.9 injections; 39 (68.4%) received all 8 injections. Injections generally were well-tolerated. Only 26 AE were attributed to AV-GBM-1, 24 grade-1 and 2 grade-2, including injection site reactions (16%), flu-like symptoms (10%), and bone discomfort (7%). The most frequent TEAE were fatigue (54)%, headache (37%), seizures (33%), nausea (30%), and focal weakness (28%). The frequency of seizures is higher than reported in other GBM trials; one patient discontinued AV-GBM-1 because of seizures. There were 55 SAE reported for 29 patients, including hospitalizations for 16 episodes of seizures in 13 patients, 7 falls in 6 patients, 6 episodes of focal weakness in 4 patients, and 3 for cerebral edema.

Conclusions

AV-GBM-1 was well-tolerated, but it was associated with a high frequency of TEAE and SAE. The high frequency of focal neurologic events may be secondary to local inflammation induced by AV-GBM-1.

Trial Registration

Clinicaltrials

gov NCT03400917

Ethics Approval

This study was approved by the Western IRB, approval number 20182582; all participants gave written informed consent before taking part

335 Leukaphereses to obtain monocytes to produce dendritic cells in manufacturing of personal autologous AV-GBM-1 vaccines in a phase II trial in patients with newly diagnosed glioblastoma

Background

For patients with newly diagnosed primary glioblastoma (GBM), maximum safe surgical resection, concurrent radiation therapy and temozolomide chemotherapy (RT/TMZ) followed by maintenance TMZ results in a 2-year survival of only 25%. Adding treatment with AV-GBM-1, a personal vaccine consisting of autologous dendritic cells (DC) pulsed with autologous tumor antigens (ATA), may improve survival. One objective of a multi-center phase II clinical trial was to determine the feasibility of collecting sufficient monocytes (MC) from which to generate DC for pulsing with ATA from GBM tumor-initiating cells (TIC).

Methods

Peripheral blood mononuclear cells were collected by leukapheresis per local standard operating procedures, then shipped by overnight courier to the AIVITA laboratory in Irvine, CA. The product was enriched for MC using the Elutra® Cell Separation System (Terumo, Lakewood, CO.). If fewer than 450 million MC were collected, an additional leukapheresis was allowed. MC were cryopreserved in liquid nitrogen and subsequently thawed and incubated in media containing granulocyte-macrophage colony-stimulating factor and interleukin-4 to differentiate MC into DC. Batches of patient-specific AV-GBM-1 were produced by incubating autologous DC with a lysate of irradiated TICs and aliquoted into individual doses.

Results

Patients enrolled from five sites in California, one in Kentucky and one in New Jersey. 65 patients underwent 77 leukapheresis procedures between September 2018 and February 2020; 54 underwent a single pheresis, 10 two phereses, and 1 three (all unsuccessful). The average time from surgical resection to first pheresis was 26 days (range 6 to 90; 64/65 within 51 days). 63/65 (97%) had sufficient MC collected, 53/65 (82%) from a single leukapheresis; 10 required a second procedure. The interval from surgery to first pheresis was the same for those for whom MC collections were satisfactory after one pheresis compared to those who required more than one. The success rate for MC collection for East-coast sites was 14/15 versus 52/62 for West-coast sites (p=0.68); so, longer shipping distance was not an issue. 60 patients who enrolled with intent-to-treat had an average of 1.7 billion monocytes cryopreserved, which were subsequently thawed and differentiated into DC. An average of 750 million DC were incubated with ATA for the final DC-ATA product.

Conclusions

Leukapheresis procedures reliably resulted in collection of sufficient numbers of monocytes to generate DC and large batches of personal AV-GBM-1 vaccines. Success after a single leukapheresis was not related to the interval from surgery to pheresis procedure, or distance from the processing site.

Trial Registration

Clinicaltrials

gov NCT03400917

Ethics Approval

This study was approved by the Western IRB, approval number 20182582; all participants gave written informed consent before taking part

Somatostatin Receptor-Targeted Radiopeptide Therapy in Treatment-Refractory Meningioma: Individual Patient Data Meta-analysis

Somatostatin receptor (SSTR)-targeted peptide receptor radionuclide therapy (PRRT) represents a promising approach for treatment-refractory meningiomas. Methods: We performed an individual patient data meta-analysis, including all published data on meningioma patients treated with SSTR-targeted PRRT. The main outcomes were toxicity, response to treatment, progression-free survival (PFS), and overall survival (OS). We applied the Kaplan-Meier method to estimate survival probabilities and report incidence rates per 100 person-years. We applied Cox proportional hazards models to determine the effect of covariates. Results: We screened 537 papers and identified 6 eligible cohort studies. We included a total of 111 patients who had treatment-refractory meningioma and received SSTR-targeted PRRT. Disease control was achieved in 63% of patients. The 6-mo PFS rates were 94%, 48%, and 0% for World Health Organization grades I, II, and III, respectively. The risk of disease progression decreased by 13% per 1,000-MBq increase in the total applied activity. The 1-y OS rates were 88%, 71%, and 52% for World Health Organization grades I, II, and III, respectively. The risk of death decreased by 17% per 1,000-MBq increase in the total applied activity. The main side effects comprised transient hematotoxicity, such as anemia in 22% of patients, leukopenia in 13%, lymphocytopenia in 24%, and thrombocytopenia in 17%. Conclusion: To our knowledge, this individual patient data meta-analysis represents the most comprehensive analysis of the benefits of and adverse events associated with SSTR-targeted PRRT for treatment-refractory meningioma. The treatment was well tolerated, achieved disease control in most cases, and showed promising results regarding PFS and OS.

Effect of Vocimagene Amiretrorepvec in Combination With Flucytosine vs Standard of Care on Survival Following Tumor Resection in Patients With Recurrent High-Grade Glioma: A Randomized Clinical Trial

Importance

New treatments are needed to improve the prognosis of patients with recurrent high-grade glioma.

Objective

To compare overall survival for patients receiving tumor resection followed by vocimagene amiretrorepvec (Toca 511) with flucytosine (Toca FC) vs standard of care (SOC).

Design, Setting, and Participants

A randomized, open-label phase 2/3 trial (TOCA 5) in 58 centers in the US, Canada, Israel, and South Korea, comparing posttumor resection treatment with Toca 511 followed by Toca FC vs a defined single choice of approved (SOC) therapies was conducted from November 30, 2015, to December 20, 2019. Patients received tumor resection for first or second recurrence of glioblastoma or anaplastic astrocytoma.

Interventions

Patients were randomized 1:1 to receive Toca 511/FC (n = 201) or SOC control (n = 202). For the Toca 511/FC group, patients received Toca 511 injected into the resection cavity wall at the time of surgery, followed by cycles of oral Toca FC 6 weeks after surgery. For the SOC control group, patients received investigators' choice of single therapy: lomustine, temozolomide, or bevacizumab.

Main Outcomes and Measures

The primary outcome was overall survival (OS) in time from randomization date to death due to any cause. Secondary outcomes reported in this study included safety, durable response rate (DRR), duration of DRR, durable clinical benefit rate, OS and DRR by IDH1 variant status, and 12-month OS.

Results

All 403 randomized patients (median [SD] age: 56 [11.46] years; 62.5% [252] men) were included in the efficacy analysis, and 400 patients were included in the safety analysis (3 patients on the SOC group did not receive resection). Final analysis included 271 deaths (141 deaths in the Toca 511/FC group and 130 deaths in the SOC control group). The median follow-up was 22.8 months. The median OS was 11.10 months for the Toca 511/FC group and 12.22 months for the control group (hazard ratio, 1.06; 95% CI 0.83, 1.35; P = .62). The secondary end points did not demonstrate statistically significant differences. The rates of adverse events were similar in the Toca 511/FC group and the SOC control group.

Conclusions and Relevance

Among patients who underwent tumor resection for first or second recurrence of glioblastoma or anaplastic astrocytoma, administration of Toca 511 and Toca FC, compared with SOC, did not improve overall survival or other efficacy end points.

Trial Registration

ClinicalTrials.gov Identifier: NCT02414165.

Development and external validation of a prognostic tool for COVID-19 critical disease

Background

The rapid spread of coronavirus disease 2019 (COVID-19) revealed significant constraints in critical care capacity. In anticipation of subsequent waves, reliable prediction of disease severity is essential for critical care capacity management and may enable earlier targeted interventions to improve patient outcomes. The purpose of this study is to develop and externally validate a prognostic model/clinical tool for predicting COVID-19 critical disease at presentation to medical care.

Methods

This is a retrospective study of a prognostic model for the prediction of COVID-19 critical disease where critical disease was defined as ICU admission, ventilation, and/or death. The derivation cohort was used to develop a multivariable logistic regression model. Covariates included patient comorbidities, presenting vital signs, and laboratory values. Model performance was assessed on the validation cohort by concordance statistics. The model was developed with consecutive patients with COVID-19 who presented to University of California Irvine Medical Center in Orange County, California. External validation was performed with a random sample of patients with COVID-19 at Emory Healthcare in Atlanta, Georgia.

Results

Of a total 3208 patients tested in the derivation cohort, 9% (299/3028) were positive for COVID-19. Clinical data including past medical history and presenting laboratory values were available for 29% (87/299) of patients (median age, 48 years [range, 21–88 years]; 64% [36/55] male). The most common comorbidities included obesity (37%, 31/87), hypertension (37%, 32/87), and diabetes (24%, 24/87). Critical disease was present in 24% (21/87). After backward stepwise selection, the following factors were associated with greatest increased risk of critical disease: number of comorbidities, body mass index, respiratory rate, white blood cell count, % lymphocytes, serum creatinine, lactate dehydrogenase, high sensitivity troponin I, ferritin, procalcitonin, and C-reactive protein. Of a total of 40 patients in the validation cohort (median age, 60 years [range, 27–88 years]; 55% [22/40] male), critical disease was present in 65% (26/40). Model discrimination in the validation cohort was high (concordance statistic: 0.94, 95% confidence interval 0.87–1.01). A web-based tool was developed to enable clinicians to input patient data and view likelihood of critical disease.

Conclusions and relevance

We present a model which accurately predicted COVID-19 critical disease risk using comorbidities and presenting vital signs and laboratory values, on derivation and validation cohorts from two different institutions. If further validated on additional cohorts of patients, this model/clinical tool may provide useful prognostication of critical care needs.

CTIM-09. DOUBLE-BLINDED, PLACEBO CONTROLLED PHASE 2 STUDY OF ERC1671 IN RECURRENT GLIOBLASTOMA: VACCINE OVERALL SURVIVAL IN BEVACIZUMAB NAIVE AND BEVACIZUMAB RESISTANT PATIENTS

ERC1671 is an allogeneic/autologous therapeutic vaccine – composed of whole, inactivated tumor cells mixed with tumor- cell lysates. The hypothesized action of ERC1671 is to potentiate the patients’ immune system against the tumor. Goals of this ongoing, phase 2 study are to determine the safety and effectiveness (overall survival) of ERC1671 in combination with GM-CSF and cyclophosphamide as an add-on treatment to bevacizumab at the time of GBM recurrence. To date 22 recurrent bevacizumab-naïve rGBM patients have been randomized to ERC1671/GM-CSF/Cyclophosphamide + Bevacizumab or Placebo + Bevacizumab. Median age is 56.5 (33–74), 7 patients (32%) are female, and average KPS is 82.3 (70–100). Of the 22, two discontinued before completing one cycle of therapy and two remain on blinded treatment. Currently 18 patients are unblinded due to further progression: 8 were on vaccine and 10 on placebo. Five of those on placebo crossed to vaccine at progression. All but one of the 18 are now deceased. Median overall survival of unblinded patients randomized to ERC1671 + Bevacizumab (n = 8) is 264.5 days from the start of study treatment, compared to 182 days for those randomized to placebo + Bevacizumab who did not cross over (n = 5). Median overall survival of unblinded patients on vaccine at randomization or crossover is 328 days after first study treatment (n = 13). While sparse, the data to date suggest pre-treatment and maximal CD4+T lymphocyte count in the peripheral blood correlate with OS more strongly in the ERC1671 group than in the placebo group. First clinical results for toxicity show no difference in the distribution of AEs between the Vaccine and Placebo groups, with no Gr4/Gr5 AEs in either group. This phase 2 randomized, double-blinded study is ongoing, with the addition of one more site.

CTIM-26. PATIENT-SPECIFIC DENDRITIC CELL VACCINE (DC-ATA) PULSED WITH ANTIGENS FROM SELF-RENEWING AUTOLOGOUS TUMOR CELLS IN THE TREATMENT OF NEWLY-DIAGNOSED GLIOBLASTOMA: A PHASE II TRIAL

GBM standard treatment is associated with poor survival. Adjunctive therapy with patient-specific vaccines may improve outcomes by enhancing anti-GBM immune responses. A multi-institutional phase II clinical trial was designed with a primary objective of 75% survival 15 months after intent-to-treat enrollment. IL-4 and GM-CSF were used to generate dendritic cells (DC) from monocytes. DC were incubated with autologous tumor antigens (ATA) from the lysate of cultured GBM cells to produce each patient-specific DC-ATA vaccine. Each dose was admixed with 500 mcg GM-CSF at the time of subcutaneous injections at weeks 1, 2, 3, 8, 12, 16, 20 and 24. Enrollment has been completed in April 2020 (n=60). Three patients withdrew from the study prior to starting treatment leaving 57 patients for whom data is available. So far 57 patients have received 344 doses; 27 have completed all 8 doses, 11 received fewer than 8 doses at the time they discontinued treatment, 19 are currently in treatment. No patient has discontinued treatment because of toxicity. 9 pt had died and the preliminary 12 months overall survival is 74%. In a preliminary serologic analysis 12 of 16 patients (75%) had an increase in markers associated with Th1/NK, Th2/immunoglobulins, and Th2 hypersensitivity (eotaxins, IgE and IL17F) by week-3; 9 of 15 (60%) had a decrease in angiogenesis factors, growth factors, and tumor markers by week-8. Immunologic data for all 55 patients who received at least two injections will be available November 2020. This patient-specific DC-ATA immunotherapy approach is feasible, is associated with changes in serologic markers, and may be increasing intratumor inflammation that may be associated with on-target toxicity and efficacy. A interim survival analysis will be conducted in mid-October 2020, 15 months after the 28th patient was enrolled; results will be available November 2020 [Clinicaltrials.gov NCT03400917].

RTID-03. A PHASE I CLINICAL TRIAL TO EVALUATE MTD OF PERAMPANEL AND MEMANTINE IN COMBINATION WITH STANDARD CHEMORADIOTHERAPY FOR THE TREATMENT OF PATIENTS WITH NEWLY DIAGNOSED GBM –A STUDY DESIGN

BACKGROUND

Glioblastoma (GBM) is the most aggressive malignant brain tumor in adults with poor prognosis. Effective treatment is urgently needed. Recent studies demonstrated cross-talk between neuron and glioma through neuro-transmitter glutamate receptors (AMPA and NMDA receptors) promotes glioma invasion and progression in vitro and in vivo. Therefore, dual blocking AMPA and NMDA receptor therapy is a potential strategy to prevent and treat GBM progression, particularly given the fact that the two blockers act through different anti-glioma mechanism. OBJECTIVE/

HYPOTHESIS

We hypothesize that adding Perampanel (an AMPA receptor blocker) and Memantine (a NMDA receptor antagonist) to standard temozolomide plus radiation therapy for the treatment of newly diagnosed GBM patients may be well tolerated and have a safe profile to prevent tumor progression, seizure recurrence or cognition impairment from radiation.

STUDY DESIGN

3 + 3 DESIGN: Maximum Tolerated Dose (MTD) is dose level at which 0/3 or 1/6 patients experience DLT with the next higher dose having at least 2/3 or 2/6 patients encountering DLT. MTD will not be more than FDA approved maximized doses for Perampanel (12 mg daily) and Memantine (20 mg bid) for the treatment of neurological diseases. Once the MTD is found, the patient will continue at MTD for the completion of concurrent chemoradiation therapy plus completion of 6 cycles of adjuvant temozolomide therapy.

SUMMARY

A Phase I trial to study the safety and toxicity of combined Perampanel and Memantine with standard chemo-radiation therapy to treat patients with newly diagnosed glioblastoma (GBM). To find Maximum Tolerated Dose (MTD) Levels of Perampanel and Memantine at concurrent chemoradiation therapy phase and adjuvant chemotherapy phase to prepare for future phase II or III trial.

RTID-04. A RANDOMIZED PHASE II TRIAL TO COMPARE THE EFFICACY OF STANDARD VERSUS COMBINATION THERAPY (PERAMPANEL, MEMANTINE PLUS STANDARD) IN THE TREATMENT OF PATIENTS WITH NEWLY DIAGNOSED GBM-A STUDY DESIGN

BACKGROUND

Glioblastoma (GBM) is the most aggressive malignant brain tumor in adults with poor prognosis. Effective treatment is urgently needed. Recent studies demonstrated neurogliomal synaptic communication through AMPA and NMDA receptors promotes glioma invasion and progression in vitro and in vivo. Therefore, dual blocking AMPA and NMDA receptor therapy is a potential enhancing strategy to prevent and to treat GBM progression given the two blockers act through different anti-glioma mechanisms.

OBJECTIVE/HYPOTHESIS

We hypothesize that adding AMPA blocker Perampanel (An anti-seizure medication) and NMDA blocker Memantine (An anti-dementia medication) to standard temozolomide plus radiation therapy (Stupp’s regimen) for the treatment of newly diagnosed GBM may prevent tumor progression. It may also reduce the frequency of onset/recurrence of seizure episodes and possibly improve radiation related cognition impairment.

STUDY DESIGN

This is a randomized, active controlled, open label, two arm phase II study of efficacy of treatment of GBM with combination therapy (dual AMPA and NMDA receptor blockers plus standard therapy) versus standard therapy. In the combination therapy arm, patients take Perampanel 2 mg daily and Memantine 5 mg bid, starting from -14 days to +14 days from initiation of concurrent chemo-radiation therapy. Titrating up at a 2 mg increment for Perampanel and 5 mg bid increment for Memantine until reaching MTD. If the patient has AE &gt;= grade 2, then reduce doses at a decrement of 2 mg for Perampanel and decrement of 5 mg bid for Memantine. In the standard therapy arm, the patients are treated with Stupp’s regimen.

PRIMARY AND SECONDARY ENDPOINTS

PFS, 12, 24 month survival rates and response duration. Safety will be assessed by CTCAE V5. We will use Kaplan-Meier estimates for survival data and a stratified log-rank test for the randomization strata.

EXTH-19. EVALUATING THE ANTI-TUMOR EFFECT OF A NOVEL THERAPEUTIC AGENT, MAGMAS INHIBITOR, IN MALIGNANT GLIOMA

BACKGROUNDS

Glioblastoma (GBM) is an aggressive infiltrative brain tumor, and has an extremely poor prognosis despite the use of multiple treatment modalities, including surgery, radiation, and chemotherapy. Meanwhile, mitochondrial changes represent a significant part of cancer cell biology since cancer cells must survive and adapt to challenging microenvironments, specifically in conditions where tumor growth makes oxygen and glucose scarce. As GBM is characterized by extensive hypoxia-induced phenotypic changes such as abnormal vascular proliferation and necrosis, regulation of mitochondrial function could be a novel approach for treating GBM that currently lacks effective therapies. Magmas (mitochondria-associated protein involved in granulocyte-macrophage colony-stimulating factor signal transduction) is a nuclear gene that encodes for the mitochondrial import inner membrane translocase subunit Tim16. We previously demonstrated that a novel Magmas inhibitor, BT#9, significantly exerted anti-tumor effect in glioma in vitro, and may cross the blood brain barrier in vivo, indicating that Magmas inhibitor may be a new chemotherapeutic agent for the treatment of GBM.

METHODS

In this study, the antitumor effect of Magmas inhibitor BT#9 was tested in an orthotopic xenograft model of human GBM. The molecular mechanism of BT#9 was investigated using glioma cell lines.

RESULTS

The mice were tolerated to BT#9, and there was no statistical difference in the weight of animals between the control and MTD (Maximum-tolerated Dose, 50mg/kg) groups. The immunocompromised mice, intracranially implanted with human D-54 GBM xenografts, survived significantly longer than the controls (P&lt; 0.5) when treated with BT#9 at MTD. In vitro study showed that the MAP kinase pathways are involved in BT#9-induced tumor suppression.

DISCUSSION

This is the first study on the role of Magmas in glioma in vivo. Our findings suggested that Magmas plays a key role in glioma survival and targeting Magmas by Magmas inhibitor has the potential to become a therapeutic strategy in glioma patients.

DDRE-22. NOVEL LonP1 INHIBITORS FOR TARGETING GLIOMA STEM CELLS

Glioblastoma (GBM) has an exceptional high rate of reoccurrence that largely explains its &lt; 15 months median survival. LonP1 is a serine protease that degrades misfolded proteins and regulates mitochondrial DNA replication. It drives tumor progression towards a malignant cancer phenotype in colorectal cancer, melanoma, oral cancer and cervical cancer. Dr. Daniela Bota has previously shown that LonP1 is overexpressed in human malignant gliomas and is associated with higher tumor grade and poor survival prognosis. In collaboration with Professor Bhaskar Das, we have used structure activity Relationship (SAR) analysis to generate compounds with on-target inhibition of LonP1 protease activity. Preliminary work on these novel compounds shows that these proprietary inhibitors can drastically decrease cell viability in the established D54 and U251 GBM lines. The lead compound BT317, shows on-target LonP1 and exceptional chymotrypsin-like proteasome inhibition. This has led to further testing, which has shown that BT317 has enhanced activity against glioma stem cell lines (GSC) and can cause global downregulation of hypoxia inducible factor 1 alpha (Hif1α) in a heterogenous GSC-derived organoid model. Finally, we have demonstrated that BT317 has less activity against differentiated GSC lines (e.g. through successive passages) and appears to have enhanced activity against TNFa-induced, differentiated GSC. This preliminary data highlights combinatorial, pharmacological LonP1 and proteasome inhibition as a novel strategy for targeting GSC in GBM.

NCMP-16. THE ROLE OF p38 AND JNK MAPK PATHWAYS IN CISPLATIN CHEMOTHERAPY-RELATED COGNITIVE IMPAIRMENT

OBJECTIVES

Chemotherapy-related cognitive impairment (CRCI) is an adverse sequela of cancer treatment commonly reported in cancer survivors. Cisplatin is used for the treatment of various malignancies including ovarian, testicular, head and neck cancers, and pediatric brain tumors. More than 30% of advanced ovarian cancer patients develop CRCI during and after platinum-based chemotherapy. We examined the role of p38 and c-Jun N-terminal kinase (JNK) mitogen-activated protein kinase (MAPK) activation in cisplatin-induced CRCI, and whether the small molecule p38 MAPK inhibitor Neflamapimod and JNK inhibitor SP600125, can prevent cisplatin-induced neuronal damage. The p38 and JNK MAPK signaling pathways are involved in various stress response pathways in the CNS including oxidative stress.

METHODS

The effect of cisplatin on cognition in an ovarian cancer female rat model was assessed by novel object recognition (NOR). Hippocampal glutathione levels were measured post-behavioral testing. P38 and JNK MAPK signaling activation were assessed in the neural cell lines PC12 and SH-SY5Y by Western blot. Cultured hippocampal neurons were pretreated with Neflamapimod or SP600125 followed by cisplatin for 24 hours, and dendritic spine density and branch length were quantified.

RESULTS

Cisplatin increased phospho-p38 and phospho-JNK MAPK protein levels in PC12 and SH-SY5Y cells. Cisplatin reduced dendritic branching and spine density, which was prevented by Neflamapimod and SP600125 pre-treatment in hippocampal neurons, in vitro. Chronic cisplatin treatment decreased hippocampal glutathione levels and impaired cognitive function in the ovarian cancer rat model.

DISCUSSION

The cognitive deficits caused by cisplatin results in part from dendritic damage and neural apoptosis, which is mediated by oxidative stress and the p38 and JNK MAPK pathways. P38 and JNK MAPK inhibition mitigated cisplatin-induced dendritic spine loss and branching in vitro. Next, we will examine whether Neflamapimod and SP600125 administration in an ovarian cancer rat model is safe and if they can prevent cognitive impairment.

Differential effects of cisplatin on cybrid cells with varying mitochondrial DNA haplogroups

Background

Drug therapy yields different results depending on its recipient population. Cisplatin, a commonly used chemotherapeutic agent, causes different levels of resistance and side effects for different patients, but the mechanism(s) are presently unknown. It has been assumed that this variation is a consequence of differences in nuclear (n) DNA, epigenetics, or some external factor(s). There is accumulating evidence that an individual's mitochondrial (mt) DNA may play a role in their response to medications. Variations within mtDNA can be observed, and an individual's mtDNA can be categorized into haplogroups that are defined by accumulations of single nucleotide polymorphisms (SNPs) representing different ethnic populations.

Methods

The present study was conducted on transmitochondrial cytoplasmic hybrids (cybrids) that possess different maternal-origin haplogroup mtDNA from African (L), Hispanic [A+B], or Asian (D) backgrounds. Cybrids were created by fusing Rho0 ARPE-19 cells (lacking mtDNA) with platelets, which contain numerous mitochondria but no nuclei. These cybrid cells were cultured to passage five, treated with cisplatin, incubated for 48 h, then analyzed for cell metabolic activity (tetrazolium dye (MTT) assay), mitochondrial membrane potential (JC-1 assay), cytotoxicity (lactate dehydrogenase (LDH) assay), and gene expression levels for ALK, BRCA1, EGFR, and ERBB2/HER2.

Results

Results indicated that untreated cybrids with varying mtDNA haplogroups had similar relative metabolic activity before cisplatin treatment. When treated with cisplatin, (1) the decline in metabolic activity was greatest in L (27.4%, p < 0.012) < D (24.86%, p = 0.0001) and [A+B] cybrids (24.67%, p = 0.0285) compared to untreated cybrids; (2) mitochondrial membrane potential remained unchanged in all cybrids (3) LDH production varied between cybrids (L >[A+B], p = 0.0270). (4) The expression levels decreased for ALK in L (p < 0.0001) and [A+B] (p = 0.0001) cybrids but not in D cybrids (p = 0.285); and decreased for EGFR in [A+B] cybrids (p = 0.0246) compared to untreated cybrids.

Conclusion

Our findings suggest that an individual's mtDNA background may be associated with variations in their response to cisplatin treatment, thereby affecting the efficiency and the severity of side effects from the treatment.

LS1 PRACTICAL APPLICATION AND UNDERLYING BIOLOGY OF TUMOR TREATING FIELDS

Glioblastoma (GBM) is the most common and most aggressive form of brain cancer in adults. For decades, the mainstay of therapeutic intervention was based on surgical resection (when safely feasible), followed by radiotherapy (RT). In 2005, data from the landmark EORTC-NCIC trial changed the standard of care treatment for GBM. This phase III trial demonstrated a survival advantage for concomitant and adjuvant temozolomide (TMZ) chemotherapy when added to the standard course of radiation. In the group of patients assigned to radiation plus TMZ, median survival improved from 12.1 months (radiotherapy alone) to 14.6 months, but all the patient finally relapsed on TMZ. In 2015, Tumor Treating Fields (TTF, Optune) became the first FDA-approved device for the treatment of for newly diagnosed GBM. This approval was based on the EF-14 clinical trial results, in which nearly half of the patients treated with Optune in combination with maintenance temozolomide (TMZ) were alive at 2 years compared with 31% of people on TMZ alone.

Optune utilize the natural electrical properties of dividing cancer cells to disrupt mitosis and provide continuous antimitotic action against progression of GBM. TTF-treated tumor cells can exit the process of mitosis aberrantly and release cellular stress signals, such as the endoplasmic reticulum chaperonin calreticulin (CRT) and high mobility group box 1 protein (HMGB1). CRT is important to induce antitumor immune responses because CRT inhibition decreases immunogenicity. HMGB1, an endogenous chromatin-associated protein released from dying tumor cells, also plays a critical role in the activation of HMGB1-mediated toll-like receptor 2 (TLR2) immune signaling. The presence of those signals may facilitate immune activation, and immunogenic induced cell death, and eventually result in tumor destruction.

In this presentation, Daniela Bota, MD, PhD, will review the clinical results of Optune in the treatment of GBM, and will discuss the novel biological mechanisms underlying the effects of Optune in controlling tumor growth and promoting the immune responses in GBM.

ATIM-28. PHASE II TRIAL OF AV-GBM-1 (AUTOLOGOUS DENDRITIC CELLS LOADED WITH TUMOR ASSOCIATED ANTIGENS) AS ADJUNCTIVE THERAPY FOLLOWING SURGERY PLUS CONCURRENT CHEMORADIATION IN NEWLY DIAGNOSED GBM PATIENTS

Newly-diagnosed glioblastoma (GBM) patients have a limited survival (18–24 months). In the last decade immunotherapy has improved survival for patients with other malignancies, but not GBM. Herein we present the design and initial enrollment results for the AV-GBM-1 single-arm phase 2 trial. The study enrolls patients with primary GBM who have undergone craniotomy, have a tumor cell culture established, and complete satisfactory leukapheresis prior to planned concurrent chemotherapy and radiation. Patients are scheduled to receive up to 8 vaccine injections at weeks 1, 2, 3, 8, 12, 16, 20 and 24. Blood samples are collected just prior to each injection. The primary endpoint is overall survival from date of enrollment for intent-to-treat with AV-GBM-1. The study has fully enrolled 26 of planned 55 patients. The cell line success rate is 30/32, with 6 in progress; successful completion of leukapheresis is 28/29. Two patients have completed all 8 doses, two discontinued after dose 3 and dose 6 because of progressive disease; 15 are currently in treatment, and 6 are about to start treatment. There have been seven SAE, all for hospitalizations related to GBM. For the first 8 treated patients, plasma samples from baseline and weeks 2, 3, and 8 have been analyzed for immune markers by RayBiotech Life Inc. using quantitative multiplex ELISA array. Markers reflecting Th1, Th2, Th17 pathways and B-cells, natural killer cells and cytotoxic T-lymphocytes increased in 7/8 patients. Principal component analysis demonstrates correlative marker groupings with early dominance of Th1/Th17 (weeks 1 and 2) followed by Th2/immunoglobulins at week 8. These findings show that these patient-specific dendritic cell vaccines are inducing pro-inflammatory responses similar to what was observed in a previous trial in melanoma. The study is progressing efficiently. Full enrollment data may be available for presentation at the time of the annual meeting.

ATIM-42. DOUBLE-BLINDED, PLACEBO CONTROLLED PHASE 2 STUDY OF ERC1671 IN RECURRENT GLIOBLASTOMA: OS CORRELATIONS WITH INITIAL AND MAXIMUM CD4+T LYMPHOCYTE COUNT IN THE PERIPHERAL BLOOD

Standard therapy for recurrent GBM is bevacizumab, a monoclonal VEGF inhibitor that targets tumor vascularization. The response to bevacizumab is transient and short-lived (4–6 months) after which patients typically develop progressive physical and mental debilitation culminating in death. ERC1671 is an allogeneic/autologous therapeutic vaccine – composed of whole, inactivated tumor cells mixed with tumor- cell lysates. The hypothesized action of ERC1671 is to potentiate the patients’ immune system against the tumor. Goals of this ongoing, phase 2 study are to to determine the safety and effectiveness (over-all survival) of ERC1671 in combination with GM-CSF and cyclophosphamide as an add-on treatment to bevacizumab at the time of GBM recurrence. To date 16 recurrent bevacizumab-naïve GBM patients have been randomized to ERC1671/GM-CSF/Cyclophosphamide + Bevacizumab or Placebo + Bevacizumab. Median age is 56.5 (39–74), 5 patients (31%) are female, and average KPS is 83 (70–100). Thirteen patients are deceased and were unblinded at the time of further progression: 5 received vaccine, 7 received placebo, and 1 is non-evaluable due to discontinuation before completing 1 cycle. Median overall survival of the deceased patients treated with ERC1671 + Bevacizumab was 328 days (10.9 months), compared to 245 days (8.2 months) for patients treated with Placebo + Bevacizumab. While sparse, the data to date suggest pre-treatment and maximal CD4+T lymphocyte count in the peripheral blood correlate with OS more strongly in the ERC1671 group than in the placebo group. First clinical results for toxicity show no difference in the distribution of AEs between the Vaccine and Placebo groups, with no Gr4/Gr5 AEs in either group. The phase 2 randomized, double-blinded study is ongoing with the addition of 2 subsites.

RARE-36. BORTEZOMIB WOKE UP A PATIENT WITH ANTI-NMDA RECEPTOR ENCEPHALITIS REFRACTORY TO STANDARD THERAPY AND LONG TERM FOLLOW-UP

OBJECTIVE

To report a case with refractory NMDA encephalitis in comatose for 18 months, who was treated successfully with bortezomib.

BACKGROUND

Anti-NMDA encephalitis is a rare autoimmune encephalitis. Standard therapy include corticosteroid, IVIG or plasma exchange, cyclophosphamide, rituximab, and tumor removal. Refractory cases are very severe and often stay in ICU on ventilation for several months to years. Bortezomib for the treatment of refractory anti-NMDA receptor encephalitis was reported. We have applied the treatment to our refractory case and successfully woke up the patient. And we have followed up the patient for 3 years.

METHODS

Case report.

RESULTS

A 40 yo male was diagnosed as anti-NMDA encephalitis. Standard therapy was applied. After stabilization, the patient was eventually discharged to ICU at a long term care subacute hospital. The patient was brought back for more Rituxan or steroid or IVIG therapy. The condition had not improved at all. Eighteen months in comatose, the patient had worsening NMDA titer in CSF to 1:640. Decision was made to start bortezumib as reported with modification: 1.3 mg/m2 bortezomib were administered on days 1, 8, 11 and 14 and allowed two weeks off therapy. After first cycle, the patent started to talk first word “hurt.” After 6 cycles, the patient sat up and started riding bicycles for physical therapy. The NMDA titer in CSF was reduced to 1:40 at the end of 6 cycles. One year later, the patent stood up and ambulated with a walker. One and half year later, the patient walks without assistance and his speech and cognition have significantly improved with good communication with family members and staff.

CONCLUSIONS

Proteasome inhibitor bortezomib might be considered to be the third line therapy as early as possible if the first line and second line are ineffective to treat anti-NMDA receptor encephalitis.

European mtDNA Variants Are Associated With Differential Responses to Cisplatin, an Anticancer Drug: Implications for Drug Resistance and Side Effects

Background: Cisplatin, a powerful antitumor agent, causes formation of DNA adducts, and activation of apoptotic pathways. Presently, cisplatin resistance develops in up to 70% of patients but the underlying molecular mechanism(s) are unclear and there are no markers to determine which patients will become resistant. Mitochondria play a significant role not only in energy metabolism but also retrograde signaling (mitochondria to nucleus) that modulates inflammation, complement, and apoptosis pathways. Maternally inherited mitochondrial (mt) DNA can be classified into haplogroups representing different ethnic populations that have diverse susceptibilities to diseases and medications. Methods: Transmitochondrial cybrids, where all cell lines possess identical nuclear genomes but either the H (Southern European) or J (Northern European) mtDNA haplogroups, were treated with cisplatin and analyzed for differential responses related to viability, oxidative stress, and expression levels of genes associated with cancer, cisplatin-induced nephrotoxicity and resistance, apoptosis and signaling pathways. Results: The cisplatin-treated-J cybrids showed greater loss of cell viability along with lower levels of reactive oxygen species and mitochondrial membrane potential compared to cisplatin-treated-H cybrids. After cisplatin treatment, J cybrids showed increased gene expression of BAX, CASP3, and CYP51A, but lower levels of SFRP1 compared to untreated-J cybrids. The cisplatin-treated-H cybrids had elevated expression of CDKN1A/P21, which has a role in cisplatin toxicity, compared to untreated-H cybrids. The cisplatin-treated H had higher transcription levels of ABCC1, DHRS2/HEP27, and EFEMP1 compared to cisplatin-treated-J cybrids. Conclusions: Cybrid cell lines that contain identical nuclei but either H mtDNA mitochondria or J mtDNA mitochondria respond differently to cisplatin treatments suggesting involvement of the retrograde signaling (from mitochondria to nucleus) in the drug-induced cell death. Varying toxicities and transcription levels of the H vs. J cybrids after cisplatin treatment support the hypothesis that mtDNA variants play a role in the expression of genes affecting resistance and side effects of cisplatin.

Somatic SMARCB1 Mutation in Sporadic Multiple Meningiomas: Case Report

Background: Multiple intracranial meningiomas account for <10% of all meningiomas. Familial multiple meningiomas have been linked to germline mutations in two genes: neurofibromatosis type 2 (NF2) and SWIch/Sucrose Non-Fermentable (SWI/SNF)-related matrix-associated actin-dependent regulator of chromatin subfamily B member 1 (SMARCB1). Sporadic multiple meningiomas have been associated with somatic NF2 mutations and, to date, there has been no case related to somatic SMARCB1 mutations. Here, we describe the first case.

Case Report: A 45-year-old female suffered a head trauma while snowboarding. Subsequent to her injury, she experienced persistent headache, nausea, vomiting, dizziness, and flashing lights in the right eye. Magnetic resonance imaging (MRI) of her brain revealed multiple intracranial meningiomas. She underwent a two-staged craniotomy to remove frontal/parietal/temporal and occipital extra-axial tumors. Pathology confirmed the masses as meningiomas, WHO Grade I. Tumor genetic testing was positive for SMARCB1 mutation but blood genetic testing was negative for SMARCB1 mutation.

Conclusion: In sporadic multiple meningiomas, somatic NF2 mutations are usually the suspected genetic alternations. Our case illustrates that somatic SMARCB1 mutation is another genetic risk factor for sporadic multiple meningiomas, albeit rare.

Deep-Learning Convolutional Neural Networks Accurately Classify Genetic Mutations in Gliomas

BACKGROUND AND PURPOSE

The World Health Organization has recently placed new emphasis on the integration of genetic information for gliomas. While tissue sampling remains the criterion standard, noninvasive imaging techniques may provide complimentary insight into clinically relevant genetic mutations. Our aim was to train a convolutional neural network to independently predict underlying molecular genetic mutation status in gliomas with high accuracy and identify the most predictive imaging features for each mutation.

MATERIALS AND METHODS

MR imaging data and molecular information were retrospectively obtained from The Cancer Imaging Archives for 259 patients with either low- or high-grade gliomas. A convolutional neural network was trained to classify isocitrate dehydrogenase 1 (IDH1) mutation status, 1p/19q codeletion, and O6-methylguanine-DNA methyltransferase (MGMT) promotor methylation status. Principal component analysis of the final convolutional neural network layer was used to extract the key imaging features critical for successful classification.

RESULTS

Classification had high accuracy: IDH1 mutation status, 94%; 1p/19q codeletion, 92%; and MGMT promotor methylation status, 83%. Each genetic category was also associated with distinctive imaging features such as definition of tumor margins, T1 and FLAIR suppression, extent of edema, extent of necrosis, and textural features.

CONCLUSIONS

Our results indicate that for The Cancer Imaging Archives dataset, machine-learning approaches allow classification of individual genetic mutations of both low- and high-grade gliomas. We show that relevant MR imaging features acquired from an added dimensionality-reduction technique demonstrate that neural networks are capable of learning key imaging components without prior feature selection or human-directed training.

Intracranial meningioma with carcinoma tumor-to-tumor metastasis: two case reports

Meningiomas have been implicated as the most common primary intracranial tumor to contain tumor-to-tumor metastasis. In the following two case reports, we describe cases of adenocarcinoma and breast carcinoma that metastasized into an intracranial meningioma. The first patient was a 64-year-old man presenting to the emergency department with seizures and loss of consciousness. After a left frontal mass resection, pathology reported a heterogeneous mass consisting of a meningioma and a metastatic adenocarcinoma component. The second patient was a 63-year-old woman presenting with significant vision problems and unstable gait. After a right frontal mass resection, pathology reported a heterogeneous mass consisting of a meningioma and a metastatic breast carcinoma component. Possible explanations for the development of the tumor-to-tumor metastasis are described.