Final report of the phase II NEXT/CNS-GCT-4 trial: GemPOx followed by marrow-ablative chemotherapy for recurrent intracranial germ cell tumors

Background

Patients with relapsed intracranial germinoma can achieve durable remission with standard chemotherapy regimens and/or reirradiation; however, innovative therapies are required for patients with relapsed and/or refractory intracranial nongerminomatous germ cell tumors (NGGCTs) due to their poor prognosis. Improved outcomes have been reported using reinduction chemotherapy to achieve minimal residual disease, followed by marrow-ablative chemotherapy (HDCx) with autologous hematopoietic progenitor cell rescue (AuHPCR). We conducted a phase II trial evaluating the response and toxicity of a 3-drug combination developed for recurrent intracranial germ cell tumors consisting of gemcitabine, paclitaxel, and oxaliplatin (GemPOx).

Methods

A total of 9 patients with confirmed relapsed or refractory intracranial GCT were enrolled after signing informed consent, and received at least 2 cycles of GemPOx, of which all but 1 had relapsed or refractory NGGCTs. One patient with progressive disease was found to have pathologically confirmed malignant transformation to pure embryonal rhabdomyosarcoma (without GCT elements), hence was ineligible and not included in the analysis. Patients who experienced sufficient responses proceeded to receive HDCx with AuHPCR. Treatment response was determined based on radiographic tumor assessments and tumor markers.

Results

A total of 7 patients achieved sufficient response and proceeded with HDCx and AuHPCR, and 5 subsequently received additional radiotherapy. A total of 2 patients developed progressive disease while receiving GemPOx. Myelosuppression and transaminitis were the most common treatment-related adverse events. With a mean follow-up of 44 months, 4 patients (3 NGGCTs, 1 germinoma) are alive without evidence of disease.

Conclusions

GemPOx demonstrates efficacy in facilitating stem cell mobilization, thus facilitating the feasibility of both HDCx and radiotherapy.

Investigative needle core biopsies for multi-omics in Glioblastoma

Glioblastoma (GBM) is a primary brain cancer with an abysmal prognosis and few effective therapies. The ability to investigate the tumor microenvironment before and during treatment would greatly enhance both understanding of disease response and progression, as well as the delivery and impact of therapeutics. Stereotactic biopsies are a routine surgical procedure performed primarily for diagnostic histopathologic purposes. The role of investigative biopsies - tissue sampling for the purpose of understanding tumor microenvironmental responses to treatment using integrated multi-modal molecular analyses ('Multi-omics") has yet to be defined. Secondly, it is unknown whether comparatively small tissue samples from brain biopsies can yield sufficient information with such methods. Here we adapt stereotactic needle core biopsy tissue in two separate patients. In the first patient with recurrent GBM we performed highly resolved multi-omics analysis methods including single cell RNA sequencing, spatial-transcriptomics, metabolomics, proteomics, phosphoproteomics, T-cell clonotype analysis, and MHC Class I immunopeptidomics from biopsy tissue that was obtained from a single procedure. In a second patient we analyzed multi-regional core biopsies to decipher spatial and genomic variance. We also investigated the utility of stereotactic biopsies as a method for generating patient derived xenograft models in a separate patient cohort. Dataset integration across modalities showed good correspondence between spatial modalities, highlighted immune cell associated metabolic pathways and revealed poor correlation between RNA expression and the tumor MHC Class I immunopeptidome. In conclusion, stereotactic needle biopsy cores are of sufficient quality to generate multi-omics data, provide data rich insight into a patient's disease process and tumor immune microenvironment and can be of value in evaluating treatment responses.

One sentence summary

Integrative multi-omics analysis of stereotactic needle core biopsies in glioblastoma.

Pembrolizumab alters the tumor immune landscape in a patient with dMMR glioblastoma

Congenital DNA mismatch repair defects (dMMR), such as Lynch Syndrome, predispose patients to a variety of cancers and account for approximately 1% of glioblastoma cases. While few therapeutic options exist for glioblastoma, checkpoint blockade therapy has proven effective in dMMR tumors. Here we present a case study of a male in their 30s diagnosed with dMMR glioblastoma treated with pembrolizumab who experienced a partial response to therapy. Using a multiplex IHC analysis pipeline on archived slide specimens from tumor resections at diagnosis and after therapeutic interventions, we quantified changes in the frequency and spatial distribution of key cell populations in the tumor tissue. Notably, proliferating (KI67+) macrophages and T cells increased in frequency as did other KI67+ cells within the tumor. Therapeutic intervention remodeled the cellular spatial distribution in the tumor leading to a greater frequency of macrophage/tumor cell interactions and T cell/T cell interactions, highlighting impacts of checkpoint blockade on tumor cytoarchitecture and revealing spatial patterns that may indicate advantageous immune interactions in glioma and other solid tumors treated with these agents.

Association between viral infections and glioma risk: a two-sample bidirectional Mendelian randomization analysis

BACKGROUND

Glioma is one of the leading types of brain tumor, but few etiologic factors of primary glioma have been identified. Previous observational research has shown an association between viral infection and glioma risk. In this study, we used Mendelian randomization (MR) analysis to explore the direction and magnitude of the causal relationship between viral infection and glioma.

METHODS

We conducted a two-sample bidirectional MR analysis using genome-wide association study (GWAS) data. Summary statistics data of glioma were collected from the largest meta-analysis GWAS, involving 12,488 cases and 18,169 controls. Single-nucleotide polymorphisms (SNPs) associated with exposures were used as instrumental variables to estimate the causal relationship between glioma and twelve types of viral infections from corresponding GWAS data. In addition, sensitivity analyses were performed.

RESULTS

After correcting for multiple tests and sensitivity analysis, we detected that genetically predicted herpes zoster (caused by Varicella zoster virus (VZV) infection) significantly decreased risk of low-grade glioma (LGG) development (OR = 0.85, 95% CI: 0.76-0.96, P = 0.01, FDR = 0.04). No causal effects of the other eleven viral infections on glioma and reverse causality were detected.

CONCLUSIONS

This is one of the first and largest studies in this field. We show robust evidence supporting that genetically predicted herpes zoster caused by VZV infection reduces risk of LGG. The findings of our research advance understanding of the etiology of glioma.

Triethylammonium salt of a synthesized dicoumarol: Structural insight and human anti-glioblastoma activities

Glioblastoma multiforme (GBM) is the most common and primary brain tumor with poor prognosis. They are removed by following tedious and life threatening surgeries. GBM stem cells (GSCs) are the main source of tumor recurrence after surgery. Hence, drugs are designed to overcome the recurrent glioblastoma malignant cells. Currently used chemotherapies are not cost effective as well as bear resistance. New and effective chemotherapeutic compounds are developed to overcome the intrinsic and acquired resistance. Dicoumarol derivative 3,3'-[(4-methoxyphenyl)methanediyl]bis(4-hydroxy-2Hchromen-2-one) (HL) and its triethylammonium salt triethylammonium3-[(4-methoxyphenyl)(4-hydroxy-2-oxo-2H-chromen-3-yl)methyl]-2-oxo-2H-chromen-4-olate (L) were synthesized and characterized using spectral and analytical techniques. The deprotonated compound L was further studied structurally using single crystal analysis. Cytotoxic studies against human glioblastoma cells A172 and LN229 were investigated both dose and time dependently and compared with the cytotoxicity of normal human astrocytes (NHA). The IC₅₀ value of HL against A172 was found to be lying within the range 2.68-0.95 μM whereas against LN229 the range was found to be 9.55-0.85 μM. Similarly, the compound L revealed range of 1.9-0.271 μM against A172 and 1.2-0.27 μM against LN229. Cell cycle arrest was observed in GBM cells treated with L compared to the control group, which suggested that L may trigger apoptosis in GBM cells according to cytotoxicity and flow cytometry results. The antioxidant activity of synthesized compounds was also investigated using DPPH free radicals.

Oncolytic DNX-2401 virotherapy plus pembrolizumab in recurrent glioblastoma: a phase 1/2 trial

Immune-mediated anti-tumoral responses, elicited by oncolytic viruses and augmented with checkpoint inhibition, may be an effective treatment approach for glioblastoma. Here in this multicenter phase 1/2 study we evaluated the combination of intratumoral delivery of oncolytic virus DNX-2401 followed by intravenous anti-PD-1 antibody pembrolizumab in recurrent glioblastoma, first in a dose-escalation and then in a dose-expansion phase, in 49 patients. The primary endpoints were overall safety and objective response rate. The primary safety endpoint was met, whereas the primary efficacy endpoint was not met. There were no dose-limiting toxicities, and full dose combined treatment was well tolerated. The objective response rate was 10.4% (90% confidence interval (CI) 4.2-20.7%), which was not statistically greater than the prespecified control rate of 5%. The secondary endpoint of overall survival at 12 months was 52.7% (95% CI 40.1-69.2%), which was statistically greater than the prespecified control rate of 20%. Median overall survival was 12.5 months (10.7-13.5 months). Objective responses led to longer survival (hazard ratio 0.20, 95% CI 0.05-0.87). A total of 56.2% (95% CI 41.1-70.5%) of patients had a clinical benefit defined as stable disease or better. Three patients completed treatment with durable responses and remain alive at 45, 48 and 60 months. Exploratory mutational, gene-expression and immunophenotypic analyses revealed that the balance between immune cell infiltration and expression of checkpoint inhibitors may potentially inform on response to treatment and mechanisms of resistance. Overall, the combination of intratumoral DNX-2401 followed by pembrolizumab was safe with notable survival benefit in select patients (ClinicalTrials.gov registration: NCT02798406).

Tumor Microenvironment in Glioblastoma: Current and Emerging Concepts

Glioblastoma (GBM) tumor microenvironment (TME) is a highly heterogeneous and complex system, which in addition to cancer cells, consists of various resident brain and immune cells as well as cells in transit through the tumor such as marrow derived immune cells. The TME is a dynamic environment which is heavily influenced by alterations in cellular composition, cell-to-cell contact and cellular metabolic products as well as other chemical factors, such as pH and oxygen levels. . Emerging evidence suggests that GBM cells appear to reprogram their the TME, and hijack microenvironmental elements to facilitate rapid proliferation, invasion, migration, and survival thus generating treatment resistance. GBM cells interact with their microenvironment directly through cell-to-cell by interaction mediated by cell-surface molecules, or indirectly through apocrine or paracrine signaling via cytokines, growth factors and extracellular vehicles. The recent discovery of neuron-glioma interfaces and neurotransmitter-based interactions has uncovered novel mechanisms that favor tumor cell survival and growth. Here, we review the known and emerging evidence related to the communication between GBM cells and various components of its TME, discuss models for studying the TME and outline current studies targeting components of the TME for therapeutic purposes.

A Case Study of Chimeric Antigen Receptor T Cell Function: Donor Therapeutic Differences in Activity and Modulation with Verteporfin

BACKGROUND

Chimeric antigen receptor (CAR) T cells have recently been demonstrated to extract and express cognate tumor antigens through trogocytosis. This process may contribute to tumor antigen escape, T cell exhaustion, and fratricide, which plays a central role in CAR dysfunction. We sought to evaluate the importance of this effect in epidermal growth factor receptor variant III (EGFRvIII) specific CAR T cells targeting glioma.

METHODS

EGFRvIII-specific CAR T cells were generated from various donors and analyzed for cytotoxicity, trogocytosis, and in vivo therapeutic activity against intracranial glioma. Tumor autophagy resulting from CAR T cell activity was evaluated in combination with an autophagy inducer (verteporfin) or inhibitor (bafilomycin A1).

RESULTS

CAR T cell products derived from different donors induced markedly divergent levels of trogocytosis of tumor antigen as well as PD-L1 upon engaging target tumor cells correlating with variability in efficacy in mice. Pharmacological facilitation of CAR induced-autophagy with verteporfin inhibits trogocytic expression of tumor antigen on CARs and increases CAR persistence and efficacy in mice.

CONCLUSION

These data propose CAR-induced autophagy as a mechanism counteracting CAR-induced trogocytosis and provide a new strategy to innovate high-performance CARs through pharmacological facilitation of T cell-induced tumor death.

BXQ-350 may alleviate symptoms of chemotherapy- induced peripheral neuropathy via modulation of S1P

93

Background: Chemotherapy Induced Peripheral Neuropathy (CIPN) is a debilitating side effect associated with many chemotherapeutic agents. It significantly impacts quality of life during treatment, causes lasting neuropathy, and may also shorten the treatment regimen, potentially impacting clinical benefit. The pathology of CIPN is still not completely understood, however, increasing evidence suggests sphingosine-1-phosphate (S1P) may be an important signaling molecule. Altered neuronal sphingolipid metabolism has been linked to neuropathic pain, evidenced by elevated plasma levels of S1P in patients receiving chemotherapy. Methods: BXQ-350 is a nanovesicle of Saposin C, an allosteric activator of sphingolipid metabolism, that lowers systemic S1P. BXQ-350 was investigated in an adult Phase 1 dose-escalation safety study in heavily pretreated all-comer cancer patients with advanced solid malignancies ( NCT02859857 ). The primary objective was to determine the safety profile and potential clinical activity of BXQ-350 as monotherapy. Samples were collected to explore potential biomarkers. Results: BXQ-350 was safe and well tolerated. Clinical signs of activity were observed in 13 patients (~17.8% of evaluable patients) experiencing a clinical benefit (PR, SD) up to cycle 6 and beyond including: 4 CRC, 1 pancreatic, and 1 GIST patient. Two patients are still on study six years after enrollment, including 1 CRC. Interestingly, a pancreatic cancer patient with chronic CIPN at time of enrollment spontaneously reported a significant improvement of her neuropathic symptoms shortly after receiving BXQ-350. Investigation of potential improvements in patients with chronic CIPN at time of enrollment revealed that 4 out of 10 patients experienced an improvement of their symptoms that seemed to be associated with a decrease in S1P systemic levels following BXQ-350 administration. BXQ-350 was subsequently investigated in a murine oxaliplatin-CIPN preclinical model with results showing a dose-dependent prevention/resolution of CIPN correlating with decreasing systemic S1P levels. Conclusions: Results of this Phase 1 study in heavily pretreated patients shows that BXQ-350 was well tolerated and seems to generate a clinical benefit via modulation of S1P. There were preliminary signs that BXQ-350 may alleviate symptoms of CIPN in relation to decreasing S1P concentration. Additional studies are underway to better understand this novel mechanism of action. Clinical trial information: 02859857 .

BXQ-350: Modulating ceramide and sphingosine-1-phosphate for antitumor activity in patients with advanced CRC

154

Background: Sphingolipids are a class of bioactive signaling molecules implicated in multiple cellular processes and molecular pathways. Many publications have demonstrated that ceramides are proapoptotic, synergize with cancer treatments, and mitigate chemoresistance. Findings also demonstrated that sphingosine-1-phosphate (S1P) is a key sphingolipid that promotes cancer cell proliferation, activates multiple oncogenic pathways, and stimulates immuno-suppressor cell populations promoting a pro-tumoral microenvironment. Several studies of colorectal cancer patients have shown high levels of ceramides being associated with improved survival, while high S1P levels are associated with a poor prognosis. Hence, modulation of sphingolipid metabolism continues to be a promising treatment approach. Methods: BXQ-350 is a nanovesicle of Saposin C, an allosteric activator of sphingolipid metabolism, that lowers systemic S1P and increases C18 ceramide. BXQ-350 was investigated in a Phase 1 dose-escalation safety study in an all-comer cancer patients with advanced solid malignancies ( NCT02859857 ) to determine its safety profile and potential clinical activity as monotherapy. Samples were collected to explore potential biomarkers. Results: 13 patients (~17.8% of evaluable patients) had a clinical benefit up to cycle 6 (PR, SD), with the majority experiencing a decrease in systemic S1P levels and an increase in C18 levels. 8 patients (~11% of evaluable patients) had PFS > 6 months, with 2 patients still on study six years after enrollment. Analysis of plasma samples also revealed an increase in anti-tumoral cytokines (IFNg, TNFa, IL-2) and a decrease in pro-tumoral ones (IL-6, 8, 10). Among patients with PFS > 6 months, there were 4 recurrent CRC patients (1PR, 3SD): 1 patient had a PFS of ~12 months, 2 of ~18 months, and 1 is still on study after 6 years. Conclusions: Results of this Phase 1 study in heavily pretreated patients show BXQ-350 was well tolerated and seem to generate a clinical benefit in CRC patients via modulation of S1P and ceramides. A phase 2 trial of BXQ-350 in combination with FOLFOX/Bevacizumab in newly diagnosed mCRC is on-going with plans to further investigate this novel mechanism of action. Clinical trial information: 02859857 .

NCCN Guidelines® Insights: Central Nervous System Cancers, Version 2.2022

The NCCN Guidelines for Central Nervous System (CNS) Cancers focus on management of the following adult CNS cancers: glioma (WHO grade 1, WHO grade 2-3 oligodendroglioma [1p19q codeleted, IDH-mutant], WHO grade 2-4 IDH-mutant astrocytoma, WHO grade 4 glioblastoma), intracranial and spinal ependymomas, medulloblastoma, limited and extensive brain metastases, leptomeningeal metastases, non-AIDS-related primary CNS lymphomas, metastatic spine tumors, meningiomas, and primary spinal cord tumors. The information contained in the algorithms and principles of management sections in the NCCN Guidelines for CNS Cancers are designed to help clinicians navigate through the complex management of patients with CNS tumors. Several important principles guide surgical management and treatment with radiotherapy and systemic therapy for adults with brain tumors. The NCCN CNS Cancers Panel meets at least annually to review comments from reviewers within their institutions, examine relevant new data from publications and abstracts, and reevaluate and update their recommendations. These NCCN Guidelines Insights summarize the panel's most recent recommendations regarding molecular profiling of gliomas.

Characterization of recurrence patterns and outcomes of medulloblastoma in adults: The University of Texas MD Anderson Cancer Center experience

Background

Medulloblastoma in adults is rare and treatment decisions are largely driven from pediatric literature. We sought to characterize recurrent medulloblastoma in adults.

Methods

From a single-institution dataset of 200 adult patients diagnosed with medulloblastoma during 1978-2017, those with recurrence were analyzed for clinical features, treatment, and outcome.

Results

Of the 200 patients, 82 (41%) with median age of 29 years (18-59) had recurrence after a median follow-up time of 8.4 years (95% CI = 7.1, 10.3). Of these, 30 (37%) were standard-risk, 31 (38%) were high-risk, and 21 (26%) had unknown-risk diseases at the time of initial diagnosis. Forty-eight (58%) presented with recurrence outside the posterior fossa, of whom 35 (43%) had distant recurrence only. Median Progression-free survival (PFS) and OS from initial surgery were 33.5 and 62.4 months, respectively. Neither PFS nor OS from initial diagnosis differed between the standard-risk and high-risk groups in those who experience recurrence (P = .505 and .463, respectively). Median OS from first recurrence was 20.3 months, also with no difference between the standard-risk and high-risk groups (P = .518). Recurrences were treated with combinations of re-resection (20 patients; 25%), systemic chemotherapy (61 patients; 76%), radiation (29 patients; 36%), stem cell transplant (6 patients; 8%), and intrathecal chemotherapy (4 patients; 5%). Patients who received radiation at recurrence had better OS (32.9 months) than those who did not (19.2 months) (P = .034).

Conclusions

Recurrent medulloblastoma in adults has a poor prognosis irrespective of initial risk stratification. Recurrence commonly arises outside the posterior fossa years after initial diagnosis.

A phase 1, safety and dose escalation study of BXQ-350, a nanovesicle formulation of saposin c, a modulator of sphingolipid metabolism, in patients with advanced solid malignancies

e15059

Background: Bexion recently completed an all-comer Phase 1 clinical study of BXQ-350 in patients with advanced solid tumors including high grade gliomas to evaluate the safety profile and to determine the maximum tolerated- or biologically effective dose. BXQ-350 is a nanovesicle comprised of recombinantly expressed Saposin C (SapC) and dioleoylphosphatidylserine. SapC, a human protein encoded by the Psap gene, is an allosteric activator of several enzymes involved sphingolipid metabolism. Sphingolipids are bioactive signaling molecules implicated in multiple cellular processes including apoptosis and immune stimulation/inhibition. In nonclinical studies, BXQ-350 evidences broad anticancer activity, selectively inducing apoptosis of cancer cells by modulating sphingolipids (ceramides/S1P), and BXQ-350 acts synergistically with multiple classes of anticancer agents and treatments. Methods: In the trial (NTC02859857), performed at four US sites, BXQ-350 was administered intravenously for a minimum of 6 cycles over 28 weeks at escalating doses from 0.7 mg/kg up to 2.4 mg/kg. Multiple secondary parameters were included to characterize its pharmacokinetics, efficacy profile and identify potential biomarkers. Results: Results indicate that: i) BXQ-350 was safe and well-tolerated as no DLT was observed and an MTD was not reached; ii) treatment related adverse events leading to discontinuation were typical for this patient population and disease related; iii)* biomarker analyses suggest positive modulation of sphingolipid metabolism and stimulation of the immune system; iv)* surprisingly, some patients noted improvement of existing peripheral neuropathies. RANO or RECIST ver 1.1 criteria were used to evaluate tumor response: 13 patients reached Cycle 6 restaging (17% ORR); 8 patients (11.0% of evaluable patients) demonstrated progression free survival over more than 6 months; and 2 patients (a GBM and CRC patient) are still on study after 5 years. * subject of separate abstracts. Conclusions: In conclusion, BXQ-350 is a first-in-human and first-in-class novel biologic whose Phase 1 results suggest that it may have clinical utility either as a monotherapy or when combined with other targeted agents. Clinical trial information: 028559857.

Infigratinib in Patients with Recurrent Gliomas and FGFR Alterations: A Multicenter Phase II Study

PURPOSE

FGFR genomic alterations (amplification, mutations, and/or fusions) occur in ∼8% of gliomas, particularly FGFR1 and FGFR3. We conducted a multicenter open-label, single-arm, phase II study of a selective FGFR1-3 inhibitor, infigratinib (BGJ398), in patients with FGFR-altered recurrent gliomas.

PATIENTS AND METHODS

Adults with recurrent/progressive gliomas harboring FGFR alterations received oral infigratinib 125 mg on days 1 to 21 of 28-day cycles. The primary endpoint was investigator-assessed 6-month progression-free survival (PFS) rate by Response Assessment in Neuro-Oncology criteria. Comprehensive genomic profiling was performed on available pretreatment archival tissue to explore additional molecular correlations with efficacy.

RESULTS

Among 26 patients, the 6-month PFS rate was 16.0% [95% confidence interval (CI), 5.0-32.5], median PFS was 1.7 months (95% CI, 1.1-2.8), and objective response rate was 3.8%. However, 4 patients had durable disease control lasting longer than 1 year. Among these, 3 had tumors harboring activating point mutations at analogous positions of FGFR1 (K656E; n = 2) or FGFR3 (K650E; n = 1) in pretreatment tissue; an FGFR3-TACC3 fusion was detected in the other. Hyperphosphatemia was the most frequently reported treatment-related adverse event (all-grade, 76.9%; grade 3, 3.8%) and is a known on-target toxicity of FGFR inhibitors.

CONCLUSIONS

FGFR inhibitor monotherapy with infigratinib had limited efficacy in a population of patients with recurrent gliomas and different FGFR genetic alterations, but durable disease control lasting more than 1 year was observed in patients with tumors harboring FGFR1 or FGFR3 point mutations or FGFR3-TACC3 fusions. A follow-up study with refined biomarker inclusion criteria and centralized FGFR testing is warranted.

Bedside to benchtop translational development: Targeting the S1P/ceramide axis may alleviate symptoms of chemical induced peripheral neuropathy

e15045

Background: Chemical Induced Peripheral Neuropathy (CIPN) is a debilitating and serious side-effect associated with many chemotherapeutic treatments. Often, CIPN is a dose-limiting toxicity, and its effects can be long-lasting in some patients. The pathology of CIPN is thought to involve not only cytotoxicity of neuronal cells, but also inflammation and immune responses. Hence, it is not surprising that the sphingolipid sphingosine-1-phosphate (S1P) is thought to be a key contributor to CIPN. Methods: BXQ-350, a nanovesicle comprised of recombinantly expressed Saposin C and dioleoylphosphatidylserine, has broad anticancer activity. It modulates sphingolipid metabolism and signaling, lowers S1P and increases pro-apoptotic ceramides, and induces an anti-tumoral immune response. BXQ-350 was investigated in a Phase 1 dose-escalation safety study of all-comer cancer patients with advanced solid malignancies, including high grade gliomas ( NCT02859857 )*. Multiple secondary parameters were included to characterize BXQ-350’s pharmacokinetics, efficacy profile and to elucidate potential biomarkers. Results: Interestingly, several patients with established CIPN spontaneously reported improvement of their neuropathy-related symptoms following BXQ-350 administration. Plasma samples from those patients revealed changes in circulating levels of sphingolipids and cytokines, including reduction of circulating levels of S1P and of IL-6, IL-8, cytokines, following BXQ-350 dosing. These properties of BXQ-350 were subsequently investigated in a murine oxaliplatin-CIPN preclinical model; results showed a dose-dependent prevention/resolution of CIPN, which also correlated with decreasing systemic S1P levels. Additional plasma based CIPN specific biomarkers were investigated, and preclinical results suggest that BXQ-350 may also favorably inhibit specific immune cells that favor CPIN. Conclusions: These preclinical and clinical observations related to CIPN, coupled with the fact that BXQ-350 acts synergistically with many chemotherapies and radiation, warrant further its investigation into preventing or improving CIPN related symptoms in cancer patients. Clinical trial information: 02859857.

Characterization of industry relationships in oncology

11025

Background: Collaborative relationships between academic oncology and the pharmaceutical industry are essential for therapeutic development in oncology. Despite this, formal training and mentorship in developing productive industry collaborations are not routinely included in oncology training. Since little research has been done to characterize and optimize the efficiency of these relationships, we sought to better understand the nature of such collaborations in order to identify areas for optimization. Methods: An electronic survey was administered to 1000 randomly selected ASCO members. The survey included 23 questions eliciting demographic and practice information, and 26 questions eliciting respondents’ views around oncology-industry collaborations. Survey results were analyzed using descriptive statistics. Results: There were 225 survey respondents. Most were from the United States (70%), worked at an academic institution (60.1%), worked in medical oncology (81.2%), and had an active relationship with industry (85.8%). 26.7 % of respondents reported difficulty establishing a relationship with industry collaborators. Many relied on federal (39.5%) or departmental (30.2%) funding to supplement their research ventures. Partnerships were initiated by the respondents themselves (34.6%) or industry partners (31.9%) with similar frequency, whereas institutional affiliations (15.7%) and collaborative groups (5.8%) were reported as less common means for establishing collaborations. The majority (85.3%) of respondents stated these collaborations were of importance to their career. Inclusion in industry sponsored trials (71.1%) and commitment to research funding (66.3%) were considered early signs of a productive relationship, whereas lack of effective communication (86.1%) or little engagement by senior industry leadership (63.1%) were early red flags. Most respondents (75%) did not report having had mentorship in developing these relationships. Scientific integrity was generally thought to be preserved (92%) and there was little concern over the quality of the collaborative product (95%). Many shared concern over potential conflict of interest if a compensated relationship promoted an industry product for clinical care/research (60%), yet also stated these relationships did not shape their interactions with patients (67%). Conclusions: This study provides novel data characterizing the nature of collaborative industry-academia relationships in oncology. While respondents considered these collaborations an important part of clinical and academic oncology, formal education or mentorship around these relationships is rare. Further study exploring the structure of effective industry collaborations, optimizing methods to provide education in this area at all career stages, navigating conflict of interest issues in these relationships, and understanding industry perspectives is warranted.

S1P/ceramides and cytokines as potential biomarkers of response following administration of bxq-350

e15007

Background: BXQ-350 was investigated in a Phase 1 dose-escalation safety study of all-comer cancer patients with advanced solid malignancies, including high grade gliomas ( NCT02859857 ) (safety/efficacy results reported in a separate abstract). The primary objective of this single agent study was to describe the safety profile and to determine the maximum tolerated dose. Multiple secondary parameters were included to characterize BXQ-350’s pharmacokinetic parameters, efficacy profile and elucidation of potential biomarkers. BXQ-350 is a nanovesicle of recombinantly expressed Saposin C (SapC) and dioleoylphosphatidylserine. In nature, SapC is a protein encoded by the Psap gene, and serves as an allosteric activator of several enzymes involved in sphingolipid/ceramide metabolism, enzymes which are being investigated as novel therapeutic targets in cancers. Indeed, sphingolipids are a class of bioactive signaling molecules implicated in multiple cellular processes and molecular pathways. Amongst these sphingolipids, Sphingosine-1-Phosphate (S1P) induces cancer cell survival and proliferation, activates multiple oncogenic pathways, and promotes a pro-tumoral microenvironment. SapC has broad anticancer activity, lowering S1P and increasing ceramides, also inducing an anti-tumoral immune response. Methods: Lipodomic analysis (sphingolipids) and cytokines were analyzed in plasma samples of a subset of patients enrolled in this study. Results: Analysis of plasma biomarker samples, collected throughout the period patients were on study, reveals notable changes of circulating sphingolipids and cytokines. A subset of patients exhibited clinical benefits following BXQ-350 administration (see other presentation for details; ̃17% of the evaluable patients remained on study up to Cycle 6; and 8 patients (̃11%) with PFS> 6 months). Concomitant circulating changes in S1P and other ceramides may be indicative of treatment effect. Also, concurrent changes in circulating levels of pro/antitumoral cytokines were noted. Conclusions: While these results are exploratory and preliminary in nature, these initial results warrant further investigation. These observations will be further explored in specific cancer and non-cancer indications. Clinical trial information: 02859857.

Multicenter phase 2 trial of the PARP inhibitor (PARPi) olaparib in recurrent IDH1 and IDH2-mutant contrast-enhancing glioma

2035

Background: Isocitrate dehydrogenase ( IDH) 1 and IDH2 mutations ( IDH1/2mt) are the most common mutations in gliomas, occurring in over 70% of low grade and 20% of higher grade gliomas. IDH1/2mts are associated with improved prognosis, although tumors typically recur and progress to a higher grade despite first lines of treatment. Recent preclinical studies have suggested IDHmt and accumulation of 2-HG confer a “BRCAness” phenotype, a vulnerability that can be targeted through PARPi. To test this hypothesis, we conducted a multicenter study of olaparib monotherapy in patients (pts) with IDH1/2mt gliomas that had progressed despite standard therapy. Methods: Eligible pts had contrast enhancing and biopsy confirmed IDH1/2mt glioma that progressed despite standard therapy. Pts with prior treatment with PARPi or IDHmt inhibitors were excluded. The primary endpoint was overall response rate (ORR). Secondary objectives were progression free survival (PFS), overall survival (OS) and duration of response (DR). Olaparib 300 mg orally twice daily was given. A standard Simon 2 stage design was used. Stage 1 included 15 pts. If 2/15 pts responded stage 2 would expand by 30 pts. Responses were assessed with RANO criteria and reviewed centrally. Results: 15 evaluable pts were enrolled. Most recent histology as per 2021 WHO classification was 12 astrocytoma (4 grade 2, 3 grade 3, 5 grade 4) and 3 oligodendroglioma (2 grade 2, 1 grade 3). A total of 13 pts’ tumors had IDH1 R132H mutations; 2 pts had IDH2mt (R172G, R172K). All pts had >1 and 10 pts had >2 prior lines of systemic therapy (median 2, range 1-4). Most toxicities were grade 1 or 2. Nausea (67%) and fatigue (47%) were most frequent. Grade 3 lymphopenia, thrombocytopenia, and hypertension were seen in 1 patient each. Best response was stable disease (SD) in 9 pts and 6 pts had disease progression (PD). The median PFS was 3.6 months, 6-month PFS rate 26.7%, median OS 13.2 months. For pts with SD, median PFS was 5.5 months; 4 pts had SD for > 6 months. 2/6 pts with PD had confirmed WHO grade 4 by histology; 4 had CDKN2A deletion. CDKN2A deletion was unknown for 2 pts. Conclusions: Olaparib was well tolerated in this pt population. The study did not meet the pre-specified response-based threshold for moving to step 2, but prolonged SD was observed in pts with grades 2 and 3 histologies, suggesting olaparib monotherapy could be of clinical benefit in select pts. Grade 4 tumors per the 2021 WHO classification defined by histology or CDKN2A mutation derived minimal to no benefit from this drug highlighting the usefulness of this new classification for future patient stratification and trial design and suggesting investigation of this treatment earlier in the disease course might be of interest. Further studies are needed to identify other molecular or clinical predictive markers of benefit from PARPi as well as novel drug combinations for improved efficacy in this population. Clinical trial information: NCT03212274.

Designing Clinical Trials for Combination Immunotherapy: A Framework for Glioblastoma

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

Disruption of DNA Repair and Survival Pathways through Heat Shock Protein inhibition by Onalespib to Sensitize Malignant Gliomas to Chemoradiation therapy

PURPOSE

Proficient DNA repair by homologous recombination (HR) facilitates resistance to chemo-radiation in glioma stem cells (GSCs). We evaluated whether compromising HR by targeting HSP90, a molecular chaperone required for the function of key HR proteins, using onalespib, a long-acting, brain-penetrant HSP90 inhibitor, would sensitize high-grade gliomas to chemo-radiation in vitro and in vivo Experimental Design: The ability of onalespib to deplete HR client proteins, impair HR repair capacity, and sensitize GBM to chemo-radiation was evaluated in vitro in GSCs, and in vivo using zebrafish and mouse intracranial glioma xenograft models. The effects of HSP90 inhibition on the transcriptome and cytoplasmic proteins was assessed in GSCs and in ex vivo organotypic human glioma slice cultures.

RESULTS

Treatment with onalespib depleted CHK1 and RAD51, two key proteins of the HR pathway, and attenuated HR repair, sensitizing GSCs to the combination of radiation and temozolomide (TMZ). HSP90 inhibition reprogrammed the transcriptome of GSCs and broadly altered expression of cytoplasmic proteins including known and novel client proteins relevant to GSCs. The combination of onalespib with radiation and TMZ extended survival in a zebra fish and a mouse xenograft model of GBM compared to the standard of care (radiation and TMZ) or onalespib with radiation.

CONCLUSIONS

The results of this study demonstrate that targeting HR by HSP90 inhibition sensitizes GSCs to radiation and chemotherapy and extends survival in zebrafish and mouse intracranial models of GBM. These results provide a preclinical rationale for assessment of HSP90 inhibitors in combination with chemoradiation in GBM patients.

Patterns of failure after radiation therapy in primary spinal high-grade gliomas: A single institutional analysis

Background

Primary spinal high-grade gliomas (S-HGG) are rare aggressive tumors; radiation therapy (RT) often plays a dominant role in management. We conducted a single-institution retrospective review to study the clinicopathological features and management of S-HGGs.

Methods

Patients with biopsy-proven S-HGG who received RT from 2001 to 2020 were analyzed for patient, tumor, and treatment characteristics. Kaplan–Meier estimates were used for survival analyses.

Results

Twenty-nine patients were identified with a median age of 25.9 years (range 1–74 y). Four patients had GTR while 25 underwent subtotal resection or biopsy. All patients were IDH wildtype and MGMT-promoter unmethylated, where available. H3K27M mutation was present in 5 out of 10 patients tested, while one patient harbored p53 mutation. Median RT dose was 50.4 Gy (range 39.6–54 Gy) and 65% received concurrent chemotherapy, most commonly temozolomide. Twenty-three (79%) of patients had documented recurrence. Overall, 16 patients relapsed locally, 10 relapsed in the brain and 8 developed leptomeningeal disease; only 8 had isolated local relapse. Median OS from diagnosis was 21.3 months and median PFS was 9.7 months. On univariate analysis, age, gender, GTR, grade, RT modality, RT dose and concurrent chemotherapy did not predict for survival. Patients with H3K27M mutation had a poorer PFS compared to those without mutation (10.1 m vs 45.1 m) but the difference did not reach statistical significance (P = .26).

Conclusions

The prognosis of patients with spinal HGGs remains poor with two-thirds of the patients developing distant recurrence despite chemoradiation. Survival outcomes were similar in patients ≤ 29 years compared to adults > 29 years. A better understanding of the molecular drivers of spinal HGGs is needed to develop more effective treatment options.

Results of a phase I trial to assess the safety of macitentan in combination with temozolomide for the treatment of recurrent glioblastoma

Background

There is an urgent need for additional therapies to treat recurrent glioblastoma (GBM). Preclinical studies suggest that high dose macitentan, an oral dual endothelin receptor antagonist, enhances the cytotoxic effects of temozolomide (TMZ) in GBM, improving survival. This phase I trial investigated the maximum tolerated dose of macitentan combined with TMZ in patients with recurrent GBM and assessed the safety and tolerability of high dose macitentan in these patients (NCT01499251).

Methods

Adults with recurrent GBM received ascending doses of macitentan from 30 mg once daily concomitantly with TMZ. Safety and tolerability were assessed in addition to exploratory efficacy and pharmacokinetic endpoints. An ancillary study examined biomarker expression following macitentan treatment prior to surgical resection of recurrent GBM.

Results

Thirty-eight patients with recurrent GBM were administered macitentan doses up to 300 mg once daily; no dose-limiting toxicities were observed, and a maximum tolerated dose was not determined. All patients experienced at least one treatment-emergent adverse event (TEAE), the majority associated with GBM or TMZ treatment. TEAEs related to macitentan and TMZ were reported for 16 (42.1%) and 26 (68.4%) patients, respectively, with no serious macitentan-related TEAEs. Macitentan concentrations increased with dose, with no plateau in exposure. Substantial heterogeneity was observed in the expression of efficacy biomarkers within tumors. The Kaplan-Meier estimate of median overall survival across all dose groups was 9.4 (95% CI 8.5, 13.4) months.

Conclusion

High-dose macitentan was well tolerated in recurrent GBM patients concomitantly receiving TMZ. TEAEs were consistent with those seen in patients receiving either drug individually.

Assessment of Leptomeningeal Carcinomatosis Diagnosis, Management and Outcomes in Patients with Solid Tumors Over a Decade of Experience

Objective

Leptomeningeal carcinomatosis (LMC), a common complication of advanced malignancies, is associated with high morbidity and mortality, yet diagnosis and treatment decisions remain challenging. This study describes the diagnostic and treatment modalities for LMC and identifies factors associated with overall survival (OS).

Materials and Methods

We performed a single-institution retrospective study (registration #: OSU2016C0053) of 153 patients diagnosed with LMC treated at The Ohio State University, Comprehensive Cancer Center, (OSUCCC)-James between January 1, 2010 and December 31, 2015.

Results

Median age at diagnosis was 55.7 years, and 61% had Eastern Cooperative Oncology Group baseline performance status ≤1. Most common primary tumors were breast (43%), lung (26%), and cutaneous melanoma (10%). At presentation, most patients were stage III-IV (71%) with higher grade tumors (grade III: 46%). Metastases to bone (36%), brain (33%), and lung (12%) were the most common sites with a median of 0.5 years (range, 0-14.9 years) between the diagnosis of first metastasis and of LMC. 153 (100%) patients had MRI evidence of LMC. Of the 67 (44%) who underwent lumbar puncture (LP), 33 (22%) had positive cerebrospinal fluid (CSF) cytology. Most patients received radiotherapy for LMC (60%) and chemotherapy (93%) for either the primary disease or LMC. 28 patients received intrathecal chemotherapy, 22 of whom had a primary diagnosis of breast cancer. 98% died with median OS of all patients was 1.9 months (95% CI: 1.3-2.5 months).

Conclusion

Despite improved treatments and targeted therapies, outcomes of LMC remain extremely poor. Positive CSF cytology was associated with lower OS in patients who had cytology assessed and specifically in patients with breast cancer. CSF cytology serves as an important indicator for prognosis and helps aid in developing individualized therapeutic strategies for patients with LMC.

Targeted Therapy for BRAF Mutant Brain Tumors

OPINION STATEMENT

Molecular heterogeneity has confounded attempts to target individual pathways in brain tumors. However, gliomas with BRAF mutations have been identified as being uniquely vulnerable to targeted therapies. Such mutations are predominantly seen in brain tumors of the adolescent and young adult population. Given that accurate and timely identification of such mutations is essential for offering appropriate treatment, treatment centers should offer both immunohistochemical and sequencing methods for detection of these mutations to guide treatment. Additional studies of these tumors at recurrence would also allow identification of breakthrough resistance mechanisms that may also be targetable for treatment. Due to the relative rarity of these tumors, multicenter collaborative studies will be essential in achieving long term control of these tumors.

Inhibition of nicotinamide phosphoribosyltransferase, the rate-limiting enzyme of the nicotinamide adenine dinucleotide salvage pathway, to target glioma heterogeneity through mitochondrial oxidative stress

BACKGROUND

Tumor-specific metabolic processes essential for cell survival are promising targets to potentially circumvent intratumoral heterogeneity, a major resistance factor in gliomas. Tumor cells preferentially using nicotinamide phosphoribosyltransferase (NAMPT), the rate-limiting enzyme in the salvage pathway for synthesis of NAD, a critical cofactor for diverse biological processes including cellular redox reactions, energy metabolism and biosynthesis. NAMPT is overexpressed in most malignancies, including gliomas, and can serve as a tumor-specific target.

METHODS

Effects of pharmacological inhibition of NAMPT on cellular oxygen consumption rate, extracellular acidification, mitochondrial respiration, cell proliferation, invasion and survival were assessed through in vitro and ex vivo studies on genetically heterogeneous glioma cell lines, glioma stem-like cells (GSCs) and mouse and human ex vivo organotypic glioma slice culture models.

RESULTS

Pharmacological inhibition of the NAD salvage biosynthesis pathway using a highly specific inhibitor, KPT-9274, resulted in reduction of NAD levels and related downstream metabolites, inhibited proliferation, and induced apoptosis in vitro in cell lines and ex vivo in human glioma tissue. These effects were mediated by mitochondrial dysfunction, DNA damage and increased oxidative stress leading to apoptosis in GSCs independent of genotype, IDH status or MGMT promoter methylation status. Conversely, NAMPT inhibition had minimal in vitro effects on normal human astrocytes (NHA) and no apparent in vivo toxicity in non-tumor-bearing mice.

CONCLUSIONS

Pharmacological NAMPT inhibition by KPT9274 potently targeted genetically heterogeneous gliomas by activating mitochondrial dysfunction. Our preclinical results provide a rationale for targeting the NAMPT-dependent alternative NAD biosynthesis pathway as a novel clinical strategy against gliomas.

Systematic review of combinations of targeted or immunotherapy in advanced solid tumors

With rapid advances in our understanding of cancer, there is an expanding number of potential novel combination therapies, including novel-novel combinations. Identifying which combinations are appropriate and in which subpopulations are among the most difficult questions in medical research. We conducted a Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA)-guided systematic review of trials of novel-novel combination therapies involving immunotherapies or molecular targeted therapies in advanced solid tumors. A MEDLINE search was conducted using a modified Cochrane Highly Sensitive Search Strategy for published clinical trials between July 1, 2017, and June 30, 2020, in the top-ranked medical and oncology journals. Trials were evaluated according to a criterion adapted from previously published Food and Drug Administration guidance and other key considerations in designing trials of combinations. This included the presence of a strong biological rationale, the use of a new established or emerging predictive biomarker prospectively incorporated into the clinical trial design, appropriate comparator arms of monotherapy or supportive external data sources and a primary endpoint demonstrating a clinically meaningful benefit. Of 32 identified trials, there were 11 (34%) trials of the novel-novel combination of anti-programmed death 1 (PD-1)/programmed death ligand 1 (PD-L1) and anti-cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) therapy, and 10 (31%) trials of anti-PD-1/PD-L1 and anti-vascular endothelial growth factor (VEGF) combination therapy. 20 (62.5%) trials were phase II trials, while 12 (37.5%) were phase III trials. Most (72%) trials lacked significant preclinical evidence supporting the development of the combination in the given indication. A majority of trials (69%) were conducted in biomarker unselected populations or used pre-existing biomarkers within the given indication for patient selection. Most studies (66%) were considered to have appropriate comparator arms or had supportive external data sources such as prior studies of monotherapy. All studies were evaluated as selecting a clinically meaningful primary endpoint. In conclusion, designing trials to evaluate novel-novel combination therapies presents numerous challenges to demonstrate efficacy in a comprehensive manner. A greater understanding of biological rationale for combinations and incorporating predictive biomarkers may improve effective evaluation of combination therapies. Innovative statistical methods and increasing use of external data to support combination approaches are potential strategies that may improve the efficiency of trial design. Designing trials to evaluate novel-novel combination therapies presents numerous challenges to demonstrate efficacy in a comprehensive manner. A greater understanding of biological rationale for combinations and incorporating predictive biomarkers may improve effective evaluation of combination therapies. Innovative statistical methods and increasing use of external data to support combination approaches are potential strategies that may improve the efficiency of trial design.

Clinical characterization of adult medulloblastoma and the effect of first-line therapies on outcome; The MD Anderson Cancer Center experience

Background

Adult medulloblastoma (MB) is rare, and management guidelines are largely based on pediatric clinical trials and retrospective series. Limited data exist with respect to clinical characteristics, prognostic factors, and outcomes based on first-line treatments.

Methods

Two hundred adults with MB seen at a single institution from January 1978 to April 2017 were identified and followed for a median of 8.4 y (7.1, 10.3).

Results

Patient’s median age at diagnosis was 29 y (18, 63). One hundred eleven (55.5%) were standard-risk, 59 (29.5%) were high-risk, and 30 (15.0%) were indeterminate. Most received post-operative radiation (RT) (184 [92.0%]), and 105 (52.5%) received first-line chemotherapy. Median overall survival (OS) was 8.8 y (7.2, 12.2) and median progression-free survival (PFS) was 6.6 y (4.9, 11.2). High-risk patients had inferior OS (Hazard ratio [HR] = 2.5 [1.5, 4.2], P = .0006) and PFS (HR = 2.3 [1.3, 3.9], P = .002) compared to standard-risk patients. Age, sex, and metastatic disease were not associated with survival. After adjusting for risk status, those who received RT plus adjuvant chemotherapy had superior PFS compared to RT plus neoadjuvant chemotherapy [HR = 0.46 (0.22, 0.95), P = .0357]. Within a subgroup for whom detailed clinical data were available, those who received RT plus adjuvant chemotherapy had improved PFS compared to RT only [HR = 0.24 (0.074–0.76), P = .016]. The substitution of cisplatin for carboplatin and the elimination of vincristine did not negatively affect outcomes.

Conclusion

This is the largest single-institution retrospective study of adult MB to our knowledge and identifies standard-risk status, first-line RT and adjuvant chemotherapy as factors associated with improved outcomes.

Tumor Treating Fields for Glioblastoma Therapy During the COVID-19 Pandemic

Background

The COVID-19 pandemic has placed excessive strain on health care systems and is especially evident in treatment decision-making for cancer patients. Glioblastoma (GBM) patients are among the most vulnerable due to increased incidence in the elderly and the short survival time. A virtual meeting was convened on May 9, 2020 with a panel of neuro-oncology experts with experience using Tumor Treating Fields (TTFields). The objective was to assess the risk-to-benefit ratio and provide guidance for using TTFields in GBM during the COVID-19 pandemic.

Panel Discussion

Topics discussed included support and delivery of TTFields during the COVID-19 pandemic, concomitant use of TTFields with chemotherapy, and any potential impact of TTFields on the immune system in an intrinsically immunosuppressed GBM population. Special consideration was given to TTFields' use in elderly patients and in combination with radiotherapy regimens. Finally, the panel discussed the need to better capture data on COVID-19positive brain tumor patients to analyze longitudinal outcomes and changes in treatment decision-making during the pandemic.

Expert Opinion

TTFields is a portable home-use device which can be managed via telemedicine and safely used in GBM patients during the COVID-19 pandemic. TTFields has no known immunosuppressive effects which is important during a crisis where other treatment methods might be limited, especially for elderly patients with multiple co-morbidities. It is too early to estimate the full impact of COVID-19 on the global healthcare system and on patient outcomes and the panel strongly recommended collaboration with existing cancer COVID-19 registries to follow CNS tumor patients.

A Bayesian adaptive randomized phase II multicenter trial of bevacizumab with or without vorinostat in adults with recurrent glioblastoma

BACKGROUND

Bevacizumab has promising activity against recurrent glioblastoma (GBM). However, acquired resistance to this agent results in tumor recurrence. We hypothesized that vorinostat, a histone deacetylase (HDAC) inhibitor with anti-angiogenic effects, would prevent acquired resistance to bevacizumab.

METHODS

This multicenter phase II trial used a Bayesian adaptive design to randomize patients with recurrent GBM to bevacizumab alone or bevacizumab plus vorinostat with the primary endpoint of progression-free survival (PFS) and secondary endpoints of overall survival (OS) and clinical outcomes assessment (MD Anderson Symptom Inventory Brain Tumor module [MDASI-BT]). Eligible patients were adults (≥18 y) with histologically confirmed GBM recurrent after prior radiation therapy, with adequate organ function, KPS ≥60, and no prior bevacizumab or HDAC inhibitors.

RESULTS

Ninety patients (bevacizumab + vorinostat: 49, bevacizumab: 41) were enrolled, of whom 74 were evaluable for PFS (bevacizumab + vorinostat: 44, bevacizumab: 30). Median PFS (3.7 vs 3.9 mo, P = 0.94, hazard ratio [HR] 0.63 [95% CI: 0.38, 1.06, P = 0.08]), median OS (7.8 vs 9.3 mo, P = 0.64, HR 0.93 [95% CI: 0.5, 1.6, P = 0.79]) and clinical benefit were similar between the 2 arms. Toxicity (grade ≥3) in 85 evaluable patients included hypertension (n = 37), neurological changes (n = 2), anorexia (n = 2), infections (n = 9), wound dehiscence (n = 2), deep vein thrombosis/pulmonary embolism (n = 2), and colonic perforation (n = 1).

CONCLUSIONS

Bevacizumab combined with vorinostat did not yield improvement in PFS or OS or clinical benefit compared with bevacizumab alone or a clinical benefit in adults with recurrent GBM. This trial is the first to test a Bayesian adaptive design with adaptive randomization and Bayesian continuous monitoring in patients with primary brain tumor and demonstrates the feasibility of using complex Bayesian adaptive design in a multicenter setting.

Phase I trial of intracerebral convection-enhanced delivery of carboplatin for treatment of recurrent high-grade gliomas

Background

Carboplatin is a potent cytoreductive agent for a variety of solid tumors. However, when delivered systemically, clinical efficacy for the treatment of high grade gliomas is poor due to limited penetration across the blood-brain barrier (BBB). Direct intracerebral (IC) convection-enhanced delivery (CED) of carboplatin has been used to bypass the BBB and successfully treat the F98 rat glioma. Based on these studies, we initiated a Phase I clinical trial.

Objective

This Phase I clinical trial was conducted to establish the maximum tolerated dose and define the toxicity profile of carboplatin delivered intracerebrally via convection enhanced delivery (CED) for patients with high grade glial neoplasms.

Methods

Cohorts of 3 patients with recurrent WHO grade III or IV gliomas were treated with escalating doses of CED carboplatin (1–4 μg in 54mL over 72 hours) delivered via catheters placed at the time of recurrent tumor resection. The primary outcome measure was determination of the maximum tolerated dose (MTD). Secondary outcome measures included overall survival (OS), progression-free survival (PFS), and radiographic correlation.

Results

A total of 10 patients have completed treatment with infusion doses of carboplatin of 1μg, 2μg, and 4μg. The total planned volume of infusion was 54mL for each patient. All patients had previously received surgery and chemoradiation. Histology at treatment include GBM (n = 9) and anaplastic oligodendroglioma (n = 1). Median KPS was 90 (range, 70 to 100) at time of treatment. Median PFS and OS were 2.1 and 9.6 months after completion of CED, respectively. A single adverse event possibly related to treatment was noted (generalized seizure).

Conclusions

IC CED of carboplatin as a potential therapy for recurrent malignant glioma is feasible and safe at doses up to 4μg in 54mL over 72 hours. Further studies are needed to determine the maximum tolerated dose and potential efficacy.

Central Nervous System Cancers, Version 3.2020, NCCN Clinical Practice Guidelines in Oncology

The NCCN Guidelines for Central Nervous System (CNS) Cancers focus on management of adult CNS cancers ranging from noninvasive and surgically curable pilocytic astrocytomas to metastatic brain disease. The involvement of an interdisciplinary team, including neurosurgeons, radiation therapists, oncologists, neurologists, and neuroradiologists, is a key factor in the appropriate management of CNS cancers. Integrated histopathologic and molecular characterization of brain tumors such as gliomas should be standard practice. This article describes NCCN Guidelines recommendations for WHO grade I, II, III, and IV gliomas. Treatment of brain metastases, the most common intracranial tumors in adults, is also described.

Early imaging marker of progressing glioblastoma: a window of opportunity

PURPOSE

Therapeutic intervention at glioblastoma (GBM) progression, as defined by current assessment criteria, is arguably too late as second-line therapies fail to extend survival. Still, most GBM trials target recurrent disease. We propose integration of a novel imaging biomarker to more confidently and promptly define progression and propose a critical timepoint for earlier intervention to extend therapeutic exposure.

METHODS

A retrospective review of 609 GBM patients between 2006 and 2019 yielded 135 meeting resection, clinical, and imaging inclusion criteria. We qualitatively and quantitatively analyzed 2000+ sequential brain MRIs (initial diagnosis to first progression) for development of T2 FLAIR signal intensity (SI) within the resection cavity (RC) compared to the ventricles (V) for quantitative inter-image normalization. PFS and OS were evaluated using Kaplan-Meier curves stratified by SI. Specificity and sensitivity were determined using a 2 × 2 table and pathology confirmation at progression. Multivariate analysis evaluated SI effect on the hazard rate for death after adjusting for established prognostic covariates. Recursive partitioning determined successive quantifiers and cutoffs associated with outcomes. Neurological deficits correlated with SI.

RESULTS

Seventy-five percent of patients developed SI on average 3.4 months before RANO-assessed progression with 84% sensitivity. SI-positivity portended neurological decline and significantly poorer outcomes for PFS (median, 10 vs. 15 months) and OS (median, 20 vs. 29 months) compared to SI-negative. RC/V ratio ≥ 4 was the most significant prognostic indicator of death.

CONCLUSION

Implications of these data are far-reaching, potentially shifting paradigms for glioma treatment response assessment, altering timepoints for salvage therapeutic intervention, and reshaping glioma clinical trial design.

Tolerability and preliminary efficacy of BXQ-350 for refractory solid tumors and high-grade gliomas: First-in-human, first-in-class phase I trial

3505

Background: BXQ-350 is a first-in-class agent comprised of Saposin C (SapC) and dioleoyl phosphatidylserine (DOPS). SapC, a multifunctional lysosomal-activator glycoprotein that preferentially interacts with tumor cell phospholipids, has demonstrated anti-tumor effects in both in vitro and in vivo preclinical models. The tolerability and preliminary efficacy of BXQ-350 in the first-in-human study are summarized here. Methods: Eighty-six refractory solid tumor (ST) or high-grade glioma (HGG) patients age ≥18 (36F:50M, age 24-81) were enrolled in a 3-part first-in-human trial (NCT02859857) from 2016-2019 and received at least one dose of BXQ-350. Doses were administered via intravenous infusion during 28-day cycles until disease progression occurred. The previously reported part 1 dose escalation portion of the study (9 HGG, 9 ST patients) established the highest planned dose of 2.4mg/kg as safe but did not identify a maximum tolerated dose. The part 2 expansion cohort treated 37 patients (18 HGG and 19 ST) and an additional part 3 cohort treated 31 ST gastrointestinal (GI) patients, both at the 2.4 mg/kg dose level. Preliminary antitumor activity was evaluated (RECISTv1.1 or RANO). Results: There were no BXQ-350-related serious adverse events, dose limiting toxicities or withdrawals with the exception of 1 allergic type reaction. Three patients (Glioblastoma, Ependymoma, Appendiceal) demonstrated a partial response per RECIST/RANO. Two HGG patients with progressive radiologic enhancement were seen to have treatment effect at surgery, and hence considered to have stable disease. Seven patients (2 HGG, 3 GI, 2 other ST) remain on study and have received treatment for 9+ to 41+ months, with 5 patients treated for > 1 year. A continuing treatment protocol is planned in order to allow these patients to remain on BXQ-350 treatment. Conclusions: BXQ-350 was well tolerated with no significant dose-limiting toxicities at the highest planed dose level. Preliminary results indicate this novel agent demonstrated possible anti-tumor activity in refractory solid tumors and HGG. Clinical trial information: NCT03967093) .

OS10.6 Infigratinib (BGJ398) in patients with recurrent gliomas with fibroblast growth factor receptor (FGFR) alterations: a multicenter phase II study

BACKGROUND

FGFR mutations and translocations occur in approximately 10% of glioblastomas (GBMs). FGFR3-TACC3 fusion has been reported as predictive of response to FGFR tyrosine kinase inhibitor therapy both pre-clinically and clinically. Infigratinib (BGJ398) is a selective small-molecule pan-FGFR kinase inhibitor that has demonstrated anti-tumor activity in several solid tumors with FGFR genetic alterations. Therefore, we conducted a phase II trial to test the efficacy of infigratinib in FGFR-altered recurrent GBM (NCT01975701).

METHODS

This open-label trial accrued adults with recurrent high-grade gliomas following failure of initial therapy that harbored FGFR1-TACC1 or FGFR3-TACC3 fusions; activating mutations in FGFR1, 2 or 3; or FGFR1, 2, 3, or 4 amplification. Oral infigratinib was administered 125 mg on days 1–21 every 28 days. Prophylaxis for hyperphosphatemia, a common toxicity, was recommended. The primary endpoint was the 6-month progression-free survival (6mPFS) rate by RANO (locally assessed, estimated by K-M method), with a goal of >40%.

RESULTS

As of the Sep 2017 data cut-off, 26 patients (16 men, 10 women; median age 55 years, range 20–76 years; 50% with ≥2 prior regimens) were treated, and 24 (92.3%) discontinued for disease progression (n=21) or other reasons (n=3). All patients had FGFR1 or FGFR3 gene alterations, and 4 had >1 gene alteration. The estimated 6mPFS rate was 16% (95% CI 5.0–32.5%); median PFS was 1.7 months (95% CI 1.1–2.8 months); median OS was 6.7 months (95% CI 4.2–11.7 months); ORR was 7.7% (95% CI 1.0–25.1%). The best overall response was: partial response 7.7% (FGFR1 mutation n=1; FGFR3 amplification n=1); stable disease 26.9%; progressive disease 50.0%; missing/unknown 15.3%. The most common (>15%) all-grade treatment-related adverse events (AEs) were hyperphosphatemia, fatigue, diarrhea, hyperlipasemia, and stomatitis. There were no grade 4 treatment-related AEs. Eleven patients (42.3%) had treatment-related AEs requiring dose interruptions or reductions (most commonly hyperphosphatemia).

CONCLUSIONS

Infigratinib induced partial response or stable disease in approximately one-third of patients with recurrent GBM and/or other glioma subtypes harboring FGFR alterations. Most AEs were reversible and manageable. Further potential combinations are being explored in patients with proven FGFR-TACC fusion genes and analysis of biomarker data is ongoing.

Stroke-Like Migraine Attacks after Radiation Therapy Syndrome: Clinical and Imaging Characteristics

Stroke-like migraine attacks after radiation therapy (SMART) syndrome is a rare, reversible phenomenon that occurs several years after radiotherapy in patients treated for intracranial neoplastic lesions. Patients typically present with symptoms of headache, seizures, and other focal neurologic deficits concerning for stroke or disease recurrence. In this report, we describe SMART syndrome in a 70-year-old male who developed a persistent right temporal headache, right-sided neck pain, and new-onset seizures 12 years after surgical resection of a temporal anaplastic ependymoma followed by irradiation. We present this case to highlight typical disease presentation, imaging characteristics, and important differential radiologic considerations. Recognition of this delayed complication of brain tumor radiation is paramount given its self-limited course and favorable response to conservative therapy and to avoid misinterpreting imaging findings as tumor recurrence.

Changing paradigms for targeted therapies against diffuse infiltrative gliomas: tackling a moving target

Introduction: Gliomas are highly heterogeneous primary brain tumors which result in a disproportionately high degree of morbidity and mortality despite their locoregional occurrence. Advances in the understanding of the biological makeup of these malignancies have yielded a number of potential tumor-driving pathways which have been identified as rational targets for therapy. However, early trials of agents that target these pathways have uniformly failed to yield improvement in outcomes in patients with malignant gliomas. Areas covered: This review provides an overview of the most common biological features of gliomas and the strategies to target the same; in addition, the current status of immunotherapy and biological therapies are outlined and the future directions to tackle the challenges of therapy for gliomas are examined. Expert opinion: The limitations of current treatments are attributed to the inability of most of these agents to cross the blood-brain barrier and to the intrinsic heterogeneity of the tumors that result in treatment resistance. The recent emergence of immune-mediated and biological therapies and of agents that target metabolic pathways in gliomas have provided strategies that may overcome tumor heterogeneity and ongoing trials of such agents are anticipated to yield improved outcomes.

Assessment of Leptomeningeal Carcinomatosis Diagnosis and Outcomes from 2005 to 2015 at Ohio State University

e13554

Background: Leptomeningeal carcinomatosis (LMC) is a complication of advanced malignancies wherein primary tumors metastasize to the leptomeninges surrounding brain and spinal cord. LMC complicates 4-15% of malignant solid tumors with incidence increasing as survival of patients with advanced cancer improves. Diagnostic methods include magnetic resonance imaging (MRI) and cerebrospinal fluid (CSF) cytology. MRI findings may be nonspecific, and the gold standard of diagnosis is malignant cytology on CSF analysis. We assessed detection methods, incidence, and outcomes of LMC at The Ohio State University Comprehensive Cancer Center from 2005-2015. Methods: This was an IRB-approved single-institution retrospective study of 160 patients with confirmed diagnosis of LMC who were treated at the OSUCCC-James between Jan 1, 2005 and Dec 31, 2015. Patients with hematologic and central nervous system malignancies were excluded. Descriptive statistics were used to summarize demographic and clinical characteristics. Overall survival (OS) was defined as time from LMC diagnosis to death or last known follow-up, and was generated using Kaplan-Meier methods. Results: Median age of LMC diagnosis was 55.8 years (range: 48, 62.5). 69 (43%) patients had primary breast cancer, 41 (26%) had lung cancer, and 17 (11%) had melanoma. 73 patients (46%) presented with stage IV disease at initial diagnosis of the primary cancer, 41 (26%) with stage III disease, and 26 (16%) with stage II disease. Median time from diagnosis of primary cancer to diagnosis of LMC was 2 years (range: 0, 31.2). 158 (99%) patients had metastases at the time of LMC diagnosis, predominantly in bone (36%) or brain (36%). Median OS was 1.9 months (CI: 1.3, 2.5). 160 (100%) patients had an MRI of the brain or spine and 155 (97%) had MRI findings consistent with LMC. 75 (47%) patients underwent lumbar puncture, and 39 (52%) had CSF cytology positive for malignancy. Conclusions: Patients with LMC commonly presented with stage IV breast cancer, lung cancer, or melanoma with metastases to the brain or bone. Despite treatment, prognosis remains poor and confirmation of diagnosis can be challenging. Clinicians should have a low threshold for investigating LMC in high risk patients presenting with neurologic signs or symptoms.

Safety and pharmacokinetics of BXQ-350 in a phase 1a and 1b trial of solid tumors and high-grade glioma

e13531

Background: BXQ-350 is composed of the multifunctional, lysosomal-activator protein Saposin C and phosphatidylserine lipid with demonstrated antitumor effects in vitro and in vivo. In this abstract we update the safety and pharmacokinetic (PK) profile based on an ongoing Phase 1 trial. Methods: BXQ-350 was administered in a Phase 1a dose-escalation trial (NCT02859857), and an ongoing Phase 1b trial (data cut off at max of 6 cycles, 01DEC2018) to refractory solid tumor/high-grade glioma patients (pts). In Phase 1a, pts received escalating IV BXQ-350 doses of 0.7, 1.1, 1.4, 1.8, or 2.4 mg/kg on days 1, 2, 3, 4, 5, 8, 10, 12, 15, 22 (cycle 1), 29 (cycle 2), and thereafter 28-day cycles. PK was assessed over a 24-hr period following the first dose. The Saposin C level was analyzed by ELISA and PK parameters were calculated using noncompartmental methods. Results: The 1a cohort of 18 pts (age 24-69) had a median of 3 cycles and 1b cohort of 20 pts (age 31-80) had median of 2 cycles with no treatment-related serious adverse events to date. Moderately severe related adverse events (AEs, n case, n events) are reported with serious non-related events. The most common treatment-related AE was fatigue (2 at dose 1.1, 2 at 1.8, 1 at 2.4mg/kg and 3 in 1b), at 2.4 mg/kg, 1 pt had moderate blood pressure elevation. Exposures in the 1.4 and 1.8 mg/kg cohorts were less than dose-proportional, likely due to higher clearance in those groups. The overall mean clearance and half-live values were 66.8 (mL/kg/h) and 4.03 h, respectively. Conclusions: BXQ-350 has had no serious related AEs during dose-escalation or in the on-going trial supporting a tolerable safety profile at 2.4 mg/kg. Clinical trial information: NCT02859857. [Table: see text]

Leptomeningeal spread of glioma in the molecular era

e13537

Background: Leptomeningeal disease (LMD) is an uncommon event in patients with gliomas which is estimated to occur in 4% of cases and is associated with poor outcome. Genomic alterations in gliomas that precipitate LMD have not been characterized. Methods: We performed a retrospective chart review of patients with gliomas (grade II-IV)- for whom we have genomic testing data at The Ohio State University. We identified patients who developed LMD. LMD was defined as leptomeningeal enhancement as seen on brain or spine imaging. Patients with negative cerebrospinal fluid (CSF) cytology were not excluded if imaging was convincing of LMD. Genomic testing was performed through Foundation One. Results: 129 charts of glioma patients were reviewed. We identified 6 patients with LMD. One is still alive. All patients were diagnosed histologically as glioblastoma. One patient had Lynch syndrome. All patients were men with a median age at diagnosis of 44 (range 20-65). All tumors appeared to have extended into the ventricles on brain imaging. 4 tumors had evidence of subependymal spread prior (range 45-93 days) or at the time of LMD enhancement. 4 patients had available CSF studies: 2 of whom had evidence of atypical or malignant cells. CSF protein was elevated in all four samples (range 113-492 mg/dL). CSF glucose was low in all four samples (range < 10-46 mg/dL). 5 tumor samples were IDH wild type whereas 1 had IDH1 R132H mutation. MGMT promoter was methylated in 3 tumors and unmethylated in 3. The genomic alterations varied among samples and included EGFR V765M mutation (N = 1), PDGFR amplification (N = 1), PDGFRA Y849C subclonal mutation (N = 1), CDKN2A/B loss (N = 3), TP53 mutations (N = 4) and TERT promoter mutations (N = 3). No case had EGFR amplification or EGFRvIII mutation. Other alterations observed included DNMT3A mutation, KIT, MYC and MDM2 amplifications and RB1 losses. PD-L1 expression ranged from 5-40%. One intracranial sample had a 20% PD-L1 expression with LMD from this tumor exhibiting 40% PD-L1 expression. Of the five deceased patients (all IDH WT), median overall survival (OS) was 355 days (range 184-557). Median OS after LMD diagnosis was 84 days (range 58-225). Conclusions: In this series, 4.5% of glioma patients developed LMD. Samples were associated with a variety of genomic alterations but without a specific predictor of leptomeningeal involvement. This is possibly due to the small number of cases. Physical proximity of the tumor to the ventricles appears to be a potential risk factor. Larger studies of LMD in gliomas are warranted to identify potential genetic drivers, if any exist.

Phase 1 lead-in to a phase 2 factorial study of temozolomide plus memantine, mefloquine, and metformin as postradiation adjuvant therapy for newly diagnosed glioblastoma

BACKGROUND

Repurposed memantine, mefloquine, and metformin have putative anticancer activity. The objective of this phase 1 study was to determine the maximum tolerated doses (MTDs) of combinations of these agents with temozolomide (TMZ).

METHODS

Adults with newly diagnosed glioblastoma who completed chemoradiation were eligible. The patients were assigned to receive doublet, triplet, or quadruplet therapy with TMZ combined with mefloquine, memantine, and/or metformin. Dose-limiting toxicities (DLTs) were determined, using a 3 + 3 study design.

RESULTS

Of 85 enrolled patients, 4 did not complete cycle 1 (the DLT observation period) for nontoxicity reasons, and 81 were evaluable for DLT. The MTDs for doublet therapy were memantine 20 mg twice daily, mefloquine 250 mg 3 times weekly, and metformin 850 mg twice daily. For triplet therapy, the MTDs were memantine 10 mg twice daily, mefloquine 250 mg 3 times weekly, and metformin 850 mg twice daily. For quadruplet therapy, the MTDs were memantine 10 mg twice daily, mefloquine 250 mg 3 times weekly, and metformin 500 mg twice daily. DLTs included dizziness (memantine) and gastrointestinal effects (metformin). Lymphopenia was the most common adverse event (66%). From study entry, the median survival was 21 months, and the 2-year survival rate was 43%.

CONCLUSIONS

Memantine, mefloquine, and metformin can be combined safely with TMZ in patients with newly diagnosed glioblastoma.

NCCN Guidelines Insights: Central Nervous System Cancers, Version 1.2017

For many years, the diagnosis and classification of gliomas have been based on histology. Although studies including large populations of patients demonstrated the prognostic value of histologic phenotype, variability in outcomes within histologic groups limited the utility of this system. Nonetheless, histology was the only proven and widely accessible tool available at the time, thus it was used for clinical trial entry criteria, and therefore determined the recommended treatment options. Research to identify molecular changes that underlie glioma progression has led to the discovery of molecular features that have greater diagnostic and prognostic value than histology. Analyses of these molecular markers across populations from randomized clinical trials have shown that some of these markers are also predictive of response to specific types of treatment, which has prompted significant changes to the recommended treatment options for grade III (anaplastic) gliomas.

Chemotherapy of High-Grade Astrocytomas in Adults

Malignant gliomas have been historically considered unresponsive to chemotherapy due to their intrinsic resistance to conventional anticancer medications and the role of the blood-brain barrier in preventing access of the cytotoxic agents to the tumor. However, recent studies have demonstrated the efficacy of specific drugs in subsets of patients with high-grade astrocytomas that has revived the enthusiasm for the role of systemic chemotherapy against these neoplasms. Temozolomide, a monofunctional alkylator, was the first chemotherapeutic agent to definitively improve survival in adults with newly diagnosed glioblastoma used in combination with radiation therapy with the most pronounced effect being in a subgroup of tumors with MGMT promoter methylation. Various other cytotoxic drugs and their combinations have been tested in this population with mostly anecdotal reports of benefit. Current efforts are directed towards identifying the subsets of patients most likely to benefit from chemotherapy and to determine the most effective treatment regimens likely to improve outcome. In addition, specific strategies in order to overcome resistance mechanisms to cytotoxic drugs and to disable cellular adaptive pathways are being explored to enhance cell kill and antitumor effects of chemotherapeutic agents.