Clinical trial links oncolytic immunoactivation to survival in glioblastoma.

Immunotherapy failures can result from the highly suppressive tumour microenvironment that characterizes aggressive forms of cancer such as recurrent glioblastoma (rGBM)1,2. Here we report the results of a first-in-human phase I trial in 41 patients with rGBM who were injected with CAN-3110-an oncolytic herpes virus (oHSV)3. In contrast to other clinical oHSVs, CAN-3110 retains the viral neurovirulence ICP34.5 gene transcribed by a nestin promoter; nestin is overexpressed in GBM and other invasive tumours, but not in the adult brain or healthy differentiated tissue4. These modifications confer CAN-3110 with preferential tumour replication. No dose-limiting toxicities were encountered. Positive HSV1 serology was significantly associated with both improved survival and clearance of CAN-3110 from injected tumours. Survival after treatment, particularly in individuals seropositive for HSV1, was significantly associated with (1) changes in tumour/PBMC T cell counts and clonal diversity, (2) peripheral expansion/contraction of specific T cell clonotypes; and (3) tumour transcriptomic signatures of immune activation. These results provide human validation that intralesional oHSV treatment enhances anticancer immune responses even in immunosuppressive tumour microenvironments, particularly in individuals with cognate serology to the injected virus. This provides a biological rationale for use of this oncolytic modality in cancers that are otherwise unresponsive to immunotherapy (ClinicalTrials.gov: NCT03152318 ).

Mechanisms and therapeutic implications of hypermutation in gliomas.

A high tumour mutational burden (hypermutation) is observed in some gliomas1-5; however, the mechanisms by which hypermutation develops and whether it predicts the response to immunotherapy are poorly understood. Here we comprehensively analyse the molecular determinants of mutational burden and signatures in 10,294 gliomas. We delineate two main pathways to hypermutation: a de novo pathway associated with constitutional defects in DNA polymerase and mismatch repair (MMR) genes, and a more common post-treatment pathway, associated with acquired resistance driven by MMR defects in chemotherapy-sensitive gliomas that recur after treatment with the chemotherapy drug temozolomide. Experimentally, the mutational signature of post-treatment hypermutated gliomas was recapitulated by temozolomide-induced damage in cells with MMR deficiency. MMR-deficient gliomas were characterized by a lack of prominent T cell infiltrates, extensive intratumoral heterogeneity, poor patient survival and a low rate of response to PD-1 blockade. Moreover, although bulk analyses did not detect microsatellite instability in MMR-deficient gliomas, single-cell whole-genome sequencing analysis of post-treatment hypermutated glioma cells identified microsatellite mutations. These results show that chemotherapy can drive the acquisition of hypermutated populations without promoting a response to PD-1 blockade and supports the diagnostic use of mutational burden and signatures in cancer.

Virtual multi-institutional tumor board: a strategy for personalized diagnoses and management of rare CNS tumors.

PURPOSE: Multidisciplinary tumor boards (MTBs) integrate clinical, molecular, and radiological information and facilitate coordination of neuro-oncology care. During the COVID-19 pandemic, our MTB transitioned to a virtual and multi-institutional format. We hypothesized that this expansion would allow expert review of challenging neuro-oncology cases and contribute to the care of patients with limited access to specialized centers. METHODS: We retrospectively reviewed records from virtual MTBs held between 04/2020-03/2021. Data collected included measures of potential clinical impact, including referrals to observational or therapeutic studies, referrals for specialized neuropathology analysis, and whether molecular findings led to a change in diagnosis and/or guided management suggestions. RESULTS: During 25 meetings, 32 presenters discussed 44 cases. Approximately half (n = 20; 48%) involved a rare central nervous system (CNS) tumor. In 21% (n = 9) the diagnosis was changed or refined based on molecular profiling obtained at the NIH and in 36% (n = 15) molecular findings guided management. Clinical trial suggestions were offered to 31% (n = 13), enrollment in the observational NCI Natural History Study to 21% (n = 9), neuropathology review and molecular testing at the NIH to 17% (n = 7), and all received management suggestions. CONCLUSION: Virtual multi-institutional MTBs enable remote expert review of CNS tumors. We propose them as a strategy to facilitate expert opinions from specialized centers, especially for rare CNS tumors, helping mitigate geographic barriers to patient care and serving as a pre-screening tool for studies. Advanced molecular testing is key to obtaining a precise diagnosis, discovering potentially actionable targets, and guiding management.

National Cancer Institute Collaborative Workshop on Shaping the Landscape of Brain Metastases Research: challenges and recommended priorities.

Brain metastases are an increasing global public health concern, even as survival rates improve for patients with metastatic disease. Both metastases and the sequelae of their treatment are key determinants of the inter-related priorities of patient survival, function, and quality of life, mandating a multidimensional approach to clinical care and research. At a virtual National Cancer Institute Workshop in September, 2022, key stakeholders convened to define research priorities to address the crucial areas of unmet need for patients with brain metastases to achieve meaningful advances in patient outcomes. This Policy Review outlines existing knowledge gaps, collaborative opportunities, and specific recommendations regarding consensus priorities and future directions in brain metastases research. Achieving major advances in research will require enhanced coordination between the ongoing efforts of individual organisations and consortia. Importantly, the continual and active engagement of patients and patient advocates will be necessary to ensure that the directionality of all efforts reflects what is most meaningful in the context of patient care.

Neurotoxicity of Cancer Immunotherapies Including CAR T Cell Therapy.

PURPOSE OF REVIEW: To outline the spectrum of neurotoxicity seen with approved immunotherapies and in pivotal clinical trials including immune checkpoint inhibitors, chimeric antigen receptor T-cell therapy, vaccine therapy, and oncolytic viruses. RECENT FINDINGS: There has been an exponential growth in new immunotherapies, which has transformed the landscape of oncology treatment. With more widespread use of cancer immunotherapies, there have also been advances in characterization of its associated neurotoxicity, research into potential underlying mechanisms, and development of management guidelines. Increasingly, there is also mounting interest in long-term neurologic sequelae. Neurologic complications of immunotherapy can impact every aspect of the central and peripheral nervous system. Early recognition and treatment are critical. Expanding indications for immunotherapy to solid and CNS tumors has led to new challenges, such as how to reliably distinguish neurotoxicity from disease progression. Our evolving understanding of immunotherapy neurotoxicity highlights important areas for future research and the need for novel immunomodulatory therapeutics.

A practical guide to neuro-oncology fellowship.

Neuro-oncology is a growing, interdisciplinary field at the intersection of neurology and oncology, devoted to the care of patients with central nervous system tumors and neurologic complications of cancer, and collaboratively interfacing with neurosurgery, neuropathology, medical oncology and radiation oncology. There is increasing trainee interest in the field of neuro-oncology and an increasing number of fellowship training programs, attracting applicants with backgrounds in neurology, neurosurgery and medical oncology. The present guide aims to provide some general recommendations for residents and fellows to help them make the most out of their neuro-oncology fellowship and enable them to start their careers as a neuro-oncologists on firm footing.

Quantitation of navtemadlin in human plasma and brain tissue by liquid chromatography-tandem mass spectrometry.

Navtemadlin is an orally bioavailable small molecule that blocks the protein-protein interaction between murine double minute 2 protein (MDM2) and the tumor suppressor protein p53, leading to p53-mediated cell cycle arrest and apoptosis. It is being evaluated in clinical trials for a variety of malignancies, both as a single agent and in combination regimens. A sensitive, robust LC-tandem mass spectrometry (LC-MS/MS) method was developed to quantitate navtemadlin in plasma, and this method was also validated using brain tissue homogenate. Sample preparation involved protein precipitation of plasma or brain tissue homogenate using acetonitrile. Navtemadlin, navtemadlin glucuronide, and the internal standard, D6 -navtemadlin, were separated from microsomal incubation extracts using gradient elution and a ZORBAX XDB C18 column. Analytes were detected using a SCIEX 5500 triple quadrupole mass spectrometer in positive electrospray ionization mode. The assay range of 1-1000 ng/mL was shown to be accurate (96.1-102.0% and 95.7-104%) and precise (coefficient of variation ≤ 10.6% and ≤ 6.6%) in plasma and brain tissue homogenate, respectively. An 8000 ng/mL navtemadlin sample diluted 1:10 (v/v) with plasma was also accurately quantitated. Navtemadlin has been stable in frozen plasma at -70°C for at least 20 months. This validated LC-MS/MS method was applied to determine navtemadlin concentrations in plasma and brain tissue samples from two separate patients receiving 120 mg/day navtemadlin on protocol ABTC1604.

Immune checkpoint inhibitors in GBM.

PURPOSE: The purpose of this review is to summarize recent updates regarding immune checkpoint inhibitor therapy in GBM patients including updates in brain immunology, clinical trials, mechanisms of resistance, and biomarkers of response. METHODS: PubMed was searched to identify recent relevant articles on immune checkpoint inhibitor therapy as it pertains to GBM. Clinicaltrials.gov was also searched to identify relevant clinical trials. RESULTS: The reported randomized phase 2 and 3 clinical trials of immune checkpoint inhibitors (alone or in combination with standard therapy) have not demonstrated a survival benefit to date in either newly diagnosed or recurrent GBM. A small randomized surgical study of neoadjuvant and adjuvant pembrolizumab suggested an increase in PFS and OS compared to adjuvant pembrolizumab only; further studies are needed to validate this finding. CONCLUSIONS: Despite the positive impact of immune checkpoint inhibitors in many cancers, only a small subset of GBM patients respond to these agents. Further research is needed to identify biomarkers of response and therapies to rationally combine with immune checkpoint inhibitors.

Neurologic Complications of Cancer Therapies.

PURPOSE OF REVIEW: To review the neurologic complications of systemic anti-cancer therapies and radiation therapy. RECENT FINDINGS: Although many of the newer systemic therapies have more favorable side effect profiles than traditional cytotoxic chemotherapy, neurotoxicity has been seen with some of newer targeted therapies, immunotherapy, and T cell engaging therapies, including CAR-T therapy. The most recent advances in radiation-induced neurotoxicity have focused on the prevention and the management of cognitive dysfunction, a known long-term complication of brain irradiation. Cancer therapies can damage both the central and the peripheral nervous systems, and the damage may not always be reversible. Neurologists and oncologists must be aware of the neurotoxicities associated with newer treatments, particularly CAR-T therapy and immunotherapy. Early recognition and appropriate management can help minimize neurologic injury.

Clinical Trial Considerations in Neuro-oncology.

OPINION STATEMENT: Clinical trials play a critical role in discovering new treatments, but the path to regulatory approval can be cumbersome and time consuming. Efforts to increase the efficiency and interpretability of clinical trials within the neuro-oncology community have focused on standardization of response assessment, development of consensus guidelines for clinical trial conduct, decentralization of clinical trials, removal of barriers to clinical trial accrual, and re-examination of patient eligibility criteria.

Neurologic complications of lung cancer.

Lung cancer and its associated treatments can cause various neurologic complications, including brain and leptomeningeal metastases, epidural spinal cord compression, cerebrovascular events, and treatment-related neurotoxicities. Lung cancer care has significantly changed in the last 5 to 10 years, with novel therapies that have affected aspects of neurologic complication management. Herein, the authors review the potential neurologic complications of lung cancer, including important clinical and therapeutic aspects of care.

NRG/RTOG 1122: A phase 2, double-blinded, placebo-controlled study of bevacizumab with and without trebananib in patients with recurrent glioblastoma or gliosarcoma.

BACKGROUND: Targeting vascular endothelial growth factor (VEGF) alone does not improve overall survival (OS) in recurrent glioblastoma (rGBM). The angiopoiein (Ang)-TIE2 system may play a role in tumor survival under VEGF inhibition. We conducted a phase 2, double-blinded, placebo-controlled trial of bevacizumab plus trebananib (a novel Fc fusion protein that sequesters Ang1/Ang2) over bevacizumab alone in rGBM. METHODS: Patients ≥18 years of age with a Karnofsky performance status ≥70 and GBM or variants in first or second relapse were randomized to bevacizumab 10 mg/kg every 2 weeks plus trebananib 15 mg/kg every week or bevacizumab plus placebo. The primary endpoint was 6-month progression-free survival (PFS). RESULTS: After an initial 6-patient lead-in cohort confirmed the safety of combining bevacizumab and trebananib, 115 eligible patients were randomized to the control (n = 58) or experimental treatment (n = 57). In the control arm, 6-month PFS was 41.1%, median survival time was 11.5 months (95% CI, 8.4-14.2 months), median PFS was 4.8 months (95% CI, 3.8-7.1 months), and radiographic response (RR) was 5.9%. In the experimental arm, 6-month PFS was 22.6%, median survival time was 7.5 months (95% CI, 6.8-10.1 months), median PFS was 4.2 months (95% CI, 3.7-5.6 months), and RR was 4.2%. The rate of severe toxicities was not significantly different between arms. CONCLUSION: The combination of bevacizumab and trebananib was well tolerated but did not significantly improve 6-month PFS rate, PFS, or OS for patients with rGBM over bevacizumab alone. The shorter PFS in the experimental arm with a hazard ratio of 1.51 (P = .04) suggests that the addition of trebananib to bevacizumab is detrimental.

Advances in Management of Brain and Leptomeningeal Metastases.

PURPOSE OF REVIEW: The management of brain and leptomeningeal metastases has changed significantly over the past decade. RECENT FINDINGS: Historically, radiation therapy had been the mainstay of treatment. Several strategies to limit toxicities with radiation have been developed in the recent years. Increasingly systemic therapy options are being considered an important therapeutic option for CNS metastases. Numerous novel small molecule inhibitors and immunotherapy agents have intracranial activity to varying degrees, in addition to good extracranial disease control. Overall, the prognosis of select patients with CNS metastases has improved over the past several years with advent of new therapeutic strategies. Systemic therapy options with CNS benefit should be considered in select patients with small and asymptomatic CNS metastases. Further areas of research focus on molecular alterations predisposing to CNS metastases, identification of small molecule inhibitors with CNS activity, and the combination of radiation therapy and immunotherapy.

Local control after brain-directed radiation in patients with cystic versus solid brain metastases.

PURPOSE: Brain metastases can be radiographically cystic or solid. Cystic metastases are associated with a greater intracranial disease burden and poorer oncologic outcomes, but the impact of cystic versus solid appearance on local control after radiation remains unknown. We investigated whether cystic versus solid nature is predictive of local control after management with stereotactic or whole brain radiation (WBRT) and whether the radiation modality utilized is an effect modifier. METHODS: We identified 859 patients with 2211 newly-diagnosed brain metastases managed with upfront stereotactic radiation or WBRT without preceding resection/aspiration at Brigham and Women's Hospital/Dana-Farber Cancer Institute between 2000 and 2015. Multivariable Cox regression with an interaction term and sandwich covariance matrix was used to quantify local failure. RESULTS: Cystic lesions were more likely to recur than solid ones when managed with stereotactic radiation (HR 2.33, 95% CI 1.32-4.10, p = 0.004) but not WBRT (HR 0.92, 95% CI 0.62-1.36, p = 0.67), p-interaction = 0.007. 1 year local control rates for cystic versus solid metastases treated with stereotactic radiation were 75% versus 88%, respectively; estimates with WBRT were 76% versus 76%, respectively. However, no significant differences were noted between the two cohorts in post-radiation outcomes including all-cause mortality and neurologic death (p > 0.05). CONCLUSIONS: Among patients with brain metastases, stereotactic radiation yields improved local control and less morbidity than WBRT, and consequently for many patients the cystic versus solid designation does not impact treatment selection. However, our results suggest that in patients with a large number of cystic brain metastases, a lower threshold to consider WBRT, as opposed to stereotactic radiation, should be employed. If our results can be confirmed, further investigation into the underlying mechanism(s) would be warranted.

Clinical trial design for systemic agents in patients with brain metastases from solid tumours: a guideline by the Response Assessment in Neuro-Oncology Brain Metastases working group.

Patients with active CNS disease are often excluded from clinical trials, and data regarding the CNS efficacy of systemic agents are usually obtained late in the drug development process or not at all. In this guideline from the Response Assessment in Neuro-Oncology Brain Metastases (RANO-BM) working group, we provide detailed recommendations on when patients with brain metastases from solid tumours should be included or excluded in clinical trials of systemic agents. We also discuss the limitations of retrospective studies in determining the CNS efficacy of systemic drugs. Inclusion of patients with brain metastases early on in the clinical development of a drug or a regimen is needed to generate appropriate CNS efficacy or non-efficacy signals. We consider how to optimally incorporate or exclude such patients in systemic therapy trials depending on the likelihood of CNS activity of the agent by considering three scenarios: drugs that are considered very unlikely to have CNS antitumour activity or efficacy; drugs that are considered very likely to have CNS activity or efficacy; and drugs with minimal baseline information on CNS activity or efficacy. We also address trial design issues unique to patients with brain metastases, including the selection of appropriate CNS endpoints in systemic therapy trials.

Clinical trial design for local therapies for brain metastases: a guideline by the Response Assessment in Neuro-Oncology Brain Metastases working group.

The goals of therapeutic and biomarker development form the foundation of clinical trial design, and change considerably from early-phase to late-phase trials. From these goals, decisions on specific clinical trial design elements, such as endpoint selection and statistical approaches, are formed. Whereas early-phase trials might focus on finding a therapeutic signal to make decisions on further development, late-phase trials focus on the confirmation of therapeutic impact by considering clinically meaningful endpoints. In this guideline from the Response Assessment in Neuro-Oncology Brain Metastases (RANO-BM) working group, we highlight issues related to, and provide recommendations for, the design of clinical trials on local therapies for CNS metastases from solid tumours. We discuss endpoint selection criteria, the analysis appropriate for early-phase and late-phase trials, the association between tumour-specific and clinically meaningful endpoints, and possible issues related to the estimation of local control in the context of competing risks. In light of these discussions, we make specific recommendations on the clinical trial design of local therapies for brain metastases.

Phase 2 and biomarker study of trebananib, an angiopoietin-blocking peptibody, with and without bevacizumab for patients with recurrent glioblastoma.

BACKGROUND: Angiopoietins contribute to tumor angiogenesis and may be upregulated as a compensatory factor after vascular endothelial growth factor (VEGF) blockade. The authors performed a phase 2 and biomarker study to evaluate trebananib, an angiopoietin 1 and angiopoietin 2 blocking peptibody, with and without bevacizumab in patients with recurrent glioblastoma. METHODS: Forty-eight patients who had bevacizumab-naive, recurrent glioblastoma were treated with trebananib (30 mg/kg weekly) as single agent (n = 11) or combined with bevacizumab (n = 37). The primary endpoint was 6-month progression-free survival rate as determined by investigator review. Circulating biomarker levels were assessed before and after study therapy. RESULTS: Trebananib was well tolerated as monotherapy and did not enhance bevacizumab-associated toxicity. Trebananib had no single-agent activity, and all treated patients exhibited progressive disease within 2 months. The 6-month progression-free survival rate for trebananib plus bevacizumab was 24.3% (95% confidence interval [CI], 12.1%-38.8%); whereas the median overall survival was 9.5 months (95% CI, 7.5-4.7 months), and the 12-month overall survival rate was 37.8% (95% CI, 22.6%-53.0%). Baseline and post-treatment changes in circulating vascular VEGF and interleukin-8 levels were correlated with survival among patients who received trebananib plus bevacizumab. CONCLUSIONS: Angiopoietin 1 and angiopoietin 2 inhibition with trebananib was ineffective as monotherapy and did not enhance the ability of VEGF blockade with bevacizumab to improve the outcomes of patients with recurrent glioblastoma. Cancer 2018;124:1438-48. © 2017 American Cancer Society.

Salvage re-irradiation for recurrent high-grade glioma and comparison to bevacizumab alone.

While salvage re-irradiation is often used for recurrent high-grade glioma (HGG), there have been few comparisons between various re-radiation dose/fractionation schedules or with bevacizumab alone. We analyzed patients with recurrent HGG who received re-irradiation at Dana-Farber Cancer Institute and Brigham and Women's Hospital from 2010 to 2014 (n = 67), as well as those who received bevacizumab alone (n = 177). Cox proportional hazards modeling was used to examine factors associated with overall survival (OS). Propensity score modeling was used to compare survival after re-irradiation vs. bevacizumab alone. Median time from initial diagnosis to re-irradiation was 31.4 months. The most common re-irradiation dose/fractionations used were 6 Gy × 5 (36%), 3.5 Gy × 10 (21%), 2.67 Gy × 15 (15%), and 18-20 Gy × 1 (15%). No early or late toxicities >grade 2 were observed. Median PFS and OS after re-irradiation were 4.8 and 10.7 months, respectively. Number of progressions prior to re-irradiation (adjusted hazard ratio [AHR] 1.6; 95% CI, 1.1-2.3; p = .007), and recurrence in a new brain location (vs. local-only; AHR 7.4; 95% CI, 2.4-23.1; p < .001) were associated with OS; dose/fractionation was not. Compared with bevacizumab alone, re-irradiated patients had a non-significant increase in OS (HR 0.80; 95% CI, 0.53-1.23; P = .31). Among patients with a local-only recurrence, there was a trend towards longer median OS after re-irradiation compared to bevacizumab alone (12.4 vs. 8.0 months; p = .12). Survival after re-irradiation for recurrent HGG appears independent of dose/fractionation and compares favorably with bevacizumab alone.

Central nervous system involvement by Waldenström macroglobulinaemia (Bing-Neel syndrome): a multi-institutional retrospective study.

Bing-Neel syndrome (BNS) is a rare complication seen in patients with Waldenström macroglobulinaemia (WM), in which lymphoplasmacytic lymphoma cells colonize the central nervous system. In this retrospective multi-centre study, we present the clinicopathological features, imaging findings, therapy, response and outcomes of 34 patients with BNS. The median time from WM diagnosis to BNS diagnosis was 3 years, 15% of patients were diagnosed with BNS at the time of WM diagnosis, and 22% of patients developed BNS when responding to active treatment for WM. Patients with BNS presented with variable clinical features including limb motor deficits, change in mental status and cranial nerve palsies. The diagnosis was made using a combination of cerebrospinal fluid cytology, flow cytometry and detection of the MYD88 L265 mutation, and magnetic resonance imaging. The estimated 3-year overall survival rate was 59%. Of the survivors, 40% have evidence of pathological and/or radiological persistence of disease. Age older than 65 years, platelet count lower than 100 × 10(9) /l, and treatment for WM prior to BNS diagnosis were associated with worse outcome. Exposure to rituximab for treatment of BNS was associated with a better outcome. Multi-institutional collaboration is warranted to improve treatment and outcomes in patients with BNS.

Assessment of Brain Tumor Response: RANO and Its Offspring.

OPINION STATEMENT: Treatment options for most nervous system tumors remain limited and patients are often confronted with significant morbidity and reduced life expectancy. However, significant efforts are underway to find more effective therapies for patients with primary and secondary brain tumors. As more and more clinical trials for nervous system tumors are being conducted, it is increasingly important to optimize the conduct of clinical trials in neuro-oncology. One of the key aspects in this regard is the development of objective and standardized criteria that allow for accurate response assessment in clinical trials and prevent the misclassification of responders and non-responders. Such misclassification may lead to premature discontinuation of an actually effective agent, thereby withholding a potentially active treatment from the patient. Conversely, patients may be inappropriately continued on an inactive treatment. Moreover, such misclassification may confound the data obtained in such studies and may lead to false conclusions with regards to the efficacy of the investigated drug. Therefore, reliable response assessment criteria are necessary that not only accurately capture radiographic changes but also account for treatment-related changes and incorporate the assessment of clinical status and quality of life (QoL). The Response Assessment in Neuro-Oncology (RANO) working group is an international collaboration of neuro-oncologists, medical oncologists, radiation oncologists, neurosurgeons, neuroradiologists, and regulatory groups (among others) commissioned to develop objective and tumor-specific response criteria for various tumor subtypes. This article reviews the currently available response criteria for high-grade glioma, low-grade glioma, and brain metastases and discusses some of the barriers to accurate assessment of treatment response in neuro-oncology.