Prospective Feasibility Trial for Genomics-Informed Treatment in Recurrent and Progressive Glioblastoma

Purpose: Glioblastoma is an aggressive and molecularly heterogeneous cancer with few effective treatment options. We hypothesized that next-generation sequencing can be used to guide treatment recommendations within a clinically acceptable time frame following surgery for patients with recurrent glioblastoma.Experimental Design: We conducted a prospective genomics-informed feasibility trial in adults with recurrent and progressive glioblastoma. Following surgical resection, genome-wide tumor/normal exome sequencing and tumor RNA sequencing were performed to identify molecular targets for potential matched therapy. A multidisciplinary molecular tumor board issued treatment recommendations based on the genomic results, blood-brain barrier penetration of the indicated therapies, drug-drug interactions, and drug safety profiles. Feasibility of generating genomics-informed treatment recommendations within 35 days of surgery was assessed.Results: Of the 20 patients enrolled in the study, 16 patients had sufficient tumor tissue for analysis. Exome sequencing was completed for all patients, and RNA sequencing was completed for 14 patients. Treatment recommendations were provided within the study's feasibility time frame for 15 of 16 (94%) patients. Seven patients received treatment based on the tumor board recommendations. Two patients reached 12-month progression-free survival, both adhering to treatments based on the molecular profiling results. One patient remained on treatment and progression free 21 months after surgery, 3 times longer than the patient's previous time to progression. Analysis of matched nonenhancing tissue from 12 patients revealed overlapping as well as novel putatively actionable genomic alterations.Conclusions: Use of genome-wide molecular profiling is feasible and can be informative for guiding real-time, central nervous system-penetrant, genomics-informed treatment recommendations for patients with recurrent glioblastoma. Clin Cancer Res; 24(2); 295-305. ©2017 AACRSee related commentary by Wick and Kessler, p. 256.

Incidence and prognosis of patients with brain metastases at diagnosis of systemic malignancy: a population-based study

BACKGROUND

Brain metastases are associated with significant morbidity and mortality. Population-level data describing the incidence and prognosis of patients with brain metastases are lacking. The aim of this study was to characterize the incidence and prognosis of patients with brain metastases at diagnosis of systemic malignancy using recently released data from the Surveillance, Epidemiology, and End Results (SEER) program.

METHODS

We identified 1302166 patients with diagnoses of nonhematologic malignancies originating outside of the CNS between 2010 and 2013 and described the incidence proportion and survival of patients with brain metastases.

RESULTS

We identified 26430 patients with brain metastases at diagnosis of cancer. Patients with small cell and non-small cell lung cancer displayed the highest rates of identified brain metastases at diagnosis; among patients presenting with metastatic disease, patients with melanoma (28.2%), lung adenocarcinoma (26.8%), non-small cell lung cancer not otherwise specified/other lung cancer (25.6%), small cell lung cancer (23.5%), squamous cell carcinoma of the lung (15.9%), bronchioloalveolar carcinoma (15.5%), and renal cancer (10.8%) had an incidence proportion of identified brain metastases of >10%. Patients with brain metastases secondary to prostate cancer, bronchioloalveolar carcinoma, and breast cancer displayed the longest median survival (12.0, 10.0, and 10.0 months, respectively).

CONCLUSIONS

In this study we provide generalizable estimates of the incidence and prognosis for patients with brain metastases at diagnosis of a systemic malignancy. These data may allow for appropriate utilization of brain-directed imaging as screening for subpopulations with cancer and have implications for clinical trial design and counseling of patients regarding prognosis.

Clinical Relevance of Steroid Use in Neuro-Oncology

BACKGROUND

Corticosteroids are commonly used in the management of primary central nervous system (CNS) tumors and CNS metastases to treat cancer- and treatment-related cerebral edema and improve neurologic function. However, they are also associated with significant morbidity and mortality, given their wide range of adverse effects.

PURPOSE OF REVIEW

To review the mechanism of action, pharmacology, and toxicity profile of corticosteroids and to critically appraise the evidence that supports their use in neuro-oncologic practice based on the latest scientific and clinical data.

RECENT FINDINGS

Recent data suggest that corticosteroids may negatively impact survival in glioma patients. In addition, corticosteroids should be incorporated as a standard criterion to assess a patient's clinical and radiographic response to treatment. Corticosteroids should be used judiciously in neuro-oncologic patients, given the potential deleterious effects on clinical outcome and patient survival. Anti-angiogenic agents, which lack these adverse effects, may be a reasonable alternative to corticosteroids.

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.

Diffusion MRI Phenotypes Predict Overall Survival Benefit from Anti-VEGF Monotherapy in Recurrent Glioblastoma: Converging Evidence from Phase II Trials

Purpose: Anti-VEGF therapies remain controversial in the treatment of recurrent glioblastoma (GBM). In the current study, we demonstrate that recurrent GBM patients with a specific diffusion MR imaging signature have an overall survival (OS) advantage when treated with cediranib, bevacizumab, cabozantinib, or aflibercept monotherapy at first or second recurrence. These findings were validated using a separate trial comparing bevacizumab with lomustine.Experimental Design: Patients with recurrent GBM and diffusion MRI from the monotherapy arms of 5 separate phase II clinical trials were included: (i) cediranib (NCT00035656); (ii) bevacizumab (BRAIN Trial, AVF3708g; NCT00345163); (iii) cabozantinib (XL184-201; NCT00704288); (iv) aflibercept (VEGF Trap; NCT00369590); and (v) bevacizumab or lomustine (BELOB; NTR1929). Apparent diffusion coefficient (ADC) histogram analysis was performed prior to therapy to estimate "ADCL," the mean of the lower ADC distribution. Pretreatment ADCL, enhancing volume, and clinical variables were tested as independent prognostic factors for OS.Results: The coefficient of variance (COV) in double baseline ADCL measurements was 2.5% and did not significantly differ (P = 0.4537). An ADCL threshold of 1.24 μm2/ms produced the largest OS differences between patients (HR ∼ 0.5), and patients with an ADCL > 1.24 μm2/ms had close to double the OS in all anti-VEGF therapeutic scenarios tested. Training and validation data confirmed that baseline ADCL was an independent predictive biomarker for OS in anti-VEGF therapies, but not in lomustine, after accounting for age and baseline enhancing tumor volume.Conclusions: Pretreatment diffusion MRI is a predictive imaging biomarker for OS in patients with recurrent GBM treated with anti-VEGF monotherapy at first or second relapse. Clin Cancer Res; 23(19); 5745-56. ©2017 AACR.

Adjuvant treatments for ependymomas

Ependymomas are rare primary central nervous system tumors occurring in children and young adults. They can be indolent or locally aggressive depending on location, histology, and extent of resection. Treatment involves maximal surgical resection and usually focal radiation therapy, depending on the presence of residual disease and tumor grade. Chemotherapy has been studied for both adults and children but do not have an established role in adjuvant therapy. In both age groups, treatment with mainly cisplatin based regimens can be considered in the setting of residual disease after surgery or for salvage therapy when surgery or further radiation is not indicated. In children, chemotherapy can be considered in very young children to delay radiation or to increase the likelihood of complete resection in second look surgery. Targeted agents such as bevacizumab and lapatinib do not have a role in adjuvant therapy for ependymomas but are being explored for recurrent disease. This review discusses adjuvant therapy in both adult and child populations.

Brain Metastases in Newly Diagnosed Breast Cancer: A Population-Based Study

Importance

Population-based estimates of the incidence and prognosis of brain metastases at diagnosis of breast cancer are lacking.

Objective

To characterize the incidence proportions and median survivals of patients with breast cancer and brain metastases at the time of cancer diagnosis.

Design, Setting, and Participants

Patients with breast cancer and brain metastases at the time of diagnosis were identified using the Surveillance, Epidemiology, and End Results (SEER) database of the National Cancer Institute. Data were stratified by subtype, age, sex, and race. Multivariable logistic and Cox regression were performed to identify predictors of the presence of brain metastases at diagnosis and factors associated with all-cause mortality, respectively. For incidence, we identified a population-based sample of 238 726 adult patients diagnosed as having invasive breast cancer between 2010 and 2013 for whom the presence or absence of brain metastases at diagnosis was known. Patients diagnosed at autopsy or with an unknown follow-up were excluded from the survival analysis, leaving 231 684 patients in this cohort.

Main Outcomes and Measures

Incidence proportion and median survival of patients with brain metastases and newly diagnosed breast cancer.

Results

We identified 968 patients with brain metastases at the time of diagnosis of breast cancer, representing 0.41% of the entire cohort and 7.56% of the subset with metastatic disease to any site. A total of 57 were 18 to 40 years old, 423 were 41 to 60 years old, 425 were 61-80 years old, and 63 were older than 80 years. Ten were male and 958 were female. Incidence proportions were highest among patients with hormone receptor (HR)-negative human epidermal growth factor receptor 2 (HER2)-positive (1.1% among entire cohort, 11.5% among patients with metastatic disease to any distant site) and triple-negative (0.7% among entire cohort, 11.4% among patients with metastatic disease to any distant site) subtypes. Median survival among the entire cohort with brain metastases was 10.0 months. Patients with HR-positive HER2-positive subtype displayed the longest median survival (21.0 months); patients with triple-negative subtype had the shortest median survival (6.0 months).

Conclusions and Relevance

The findings of this study provides population-based estimates of the incidence and prognosis for patients with brain metastases at time of diagnosis of breast cancer. The findings lend support to consideration of screening imaging of the brain for patients with HER2-positive or triple-negative subtypes and extracranial metastases.

Response Assessment in Neuro-Oncology Clinical Trials

Development of novel therapies for CNS tumors requires reliable assessment of response and progression. This requirement has been particularly challenging in neuro-oncology for which contrast enhancement serves as an imperfect surrogate for tumor volume and is influenced by agents that affect vascular permeability, such as antiangiogenic therapies. In addition, most tumors have a nonenhancing component that can be difficult to accurately quantify. To improve the response assessment in neuro-oncology and to standardize the criteria that are used for different CNS tumors, the Response Assessment in Neuro-Oncology (RANO) working group was established. This multidisciplinary international working group consists of neuro-oncologists, medical oncologists, neuroradiologists, neurosurgeons, radiation oncologists, neuropsychologists, and experts in clinical outcomes assessments, working in collaboration with government and industry to enhance the interpretation of clinical trials. The RANO working group was originally created to update response criteria for high- and low-grade gliomas and to address such issues as pseudoresponse and nonenhancing tumor progression from antiangiogenic therapies, and pseudoprogression from radiochemotherapy. RANO has expanded to include working groups that are focused on other tumors, including brain metastases, leptomeningeal metastases, spine tumors, pediatric brain tumors, and meningiomas, as well as other clinical trial end points, such as clinical outcomes assessments, seizures, corticosteroid use, and positron emission tomography imaging. In an effort to standardize the measurement of neurologic function for clinical assessment, the Neurologic Assessment in Neuro-Oncology scale was drafted. Born out of a workshop conducted by the Jumpstarting Brain Tumor Drug Development Coalition and the US Food and Drug Administration, a standardized brain tumor imaging protocol now exists to reduce variability and improve reliability. Efforts by RANO have been widely accepted and are increasingly being used in neuro-oncology trials, although additional refinements will be needed.

Abstract 4974: Pharmacogenomic interactions in glioblastoma cell line models

Glioblastoma (GBM) is the most common and malignant brain tumor. These tumors display a uniform and very short survival time even with treatment, but are highly heterogeneous at the histological and genomic level. To identify effective treatments and dependencies, we profiled the sensitivity of a panel of cancer cell lines to a small molecules and integrated this with systematic analysis of genetic and non-genetic determinants associated with chemical response.

Methods. We profiled 381 drugs described in the Cancer Therapeutics Response Portal (CTRP) at 16 different duplicated concentrations across 78 GBM cell lines belonging to two different models: Patient-Derived GBM Cell Lines (PDGCL) and Long-Term GBM Cell Lines (LTGCL) previously included in the Cancer Cell Line Encyclopedia (CCLE). Cell lines were deeply characterized as to genotype and phenotype. As non-genomic determinants we considered: model, growth rate, behavior, stem cell and differentiation markers. Genomic determinants included mutations and somatic copy number alterations (SCNA) computed from whole exome sequencing. Each of these were integrated to determine oncogene and tumor suppressor gene pathway disruption (p53, RB and RTK signaling). At transcriptomic level we considered expression of 20.647 genes and patters described in GBMs (proneural, neural, classical, mesenchymal). Overall we correlated 10,859,643 pharmacogenomic features to discover associations with drug sensitivity.

Summary. We developed a brain tumor living tissue bank as platform for preclinical pharmacogenomics analysis. Large-scale phenotypic characterization of GBM models showed increased cellular and molecular heterogeneity among PDGCLs compared to LTGCLs. PDGCLs better recapitulated patient GBM copy-number profiles. GBM cell lines exhibited all major driver mutations in human GBMs, except IDH1. PDGCLs and LTGCLs enriched for proneural and mesenchymal phenotypes, respectively. We identified NAMPT inhibitors as among the compounds with highest activity across cell lines. Integrative pharmacogenomic analyses showed MDM2/4 inhibitors were able to effectively suppress TP53 wild type GBM models, being CDKN1A (p21) expression a robust predictor of drug response in vitro and in vivo. Overall drug resistance across the screen in lines was highly associated with TP53 mutation, however a specific subset of TP53 mutant cell lines bearing simultaneous CDKN2A/B deletions were sensitive to CHK1/2 inhibitors, revealing a potential synthetic lethal interaction of clinical significance in these highly refractory cells.

Analysis identified genetic alterations associated with vulnerabilities targeted by small molecules. About 85% of GBM patients display p53 pathway disruption, our results suggest independent pharmacological strategies for two genetic subtypes of GBM determined by TP53 and CDKN1A status. Our analyses provide molecular insights to drive targeted therapies in the new era of precision medicine.

Citation Format: Ruben Ferrer-Luna, Shakti H. Ramkissoon, Karl H. Olausson, Lori A. Ramkissoon, Steven Schumacher, Rebecca Lamothe, Jaime H. Cheah, Kristine Pellton, Sam Haidar, Yun J. Kang, Brenton R. Paolella, Cecile Maire, Wenyu Song, Alice Meng, Ahmed Idbaih, Mikael L. Rinne, David A. Reardon, Patrick Y. Wen, Paul A. Clemons, Stuart L. Schreiber, Alykhan F. Shamji, Rameen Beroukhim, Keith L. Ligon. Pharmacogenomic interactions in glioblastoma cell line models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4974. doi:10.1158/1538-7445.AM2017-4974

Early changes in glioblastoma metabolism measured by MR spectroscopic imaging during combination of anti-angiogenic cediranib and chemoradiation therapy are associated with survival

Precise assessment of treatment response in glioblastoma during combined anti-angiogenic and chemoradiation remains a challenge. In particular, early detection of treatment response by standard anatomical imaging is confounded by pseudo-response or pseudo-progression. Metabolic changes may be more specific for tumor physiology and less confounded by changes in blood-brain barrier permeability. We hypothesize that metabolic changes probed by magnetic resonance spectroscopic imaging can stratify patient response early during combination therapy. We performed a prospective longitudinal imaging study in newly diagnosed glioblastoma patients enrolled in a phase II clinical trial of the pan-vascular endothelial growth factor receptor inhibitor cediranib in combination with standard fractionated radiation and temozolomide (chemoradiation). Forty patients were imaged weekly during therapy with an imaging protocol that included magnetic resonance spectroscopic imaging, perfusion magnetic resonance imaging, and anatomical magnetic resonance imaging. Data were analyzed using receiver operator characteristics, Cox proportional hazards model, and Kaplan-Meier survival plots. We observed that the ratio of total choline to healthy creatine after 1 month of treatment was significantly associated with overall survival, and provided as single parameter: (1) the largest area under curve (0.859) in receiver operator characteristics, (2) the highest hazard ratio (HR = 85.85, P = 0.006) in Cox proportional hazards model, (3) the largest separation (P = 0.004) in Kaplan-Meier survival plots. An inverse correlation was observed between total choline/healthy creatine and cerebral blood flow, but no significant relation to tumor volumetrics was identified. Our results suggest that in vivo metabolic biomarkers obtained by magnetic resonance spectroscopic imaging may be an early indicator of response to anti-angiogenic therapy combined with standard chemoradiation in newly diagnosed glioblastoma.

Phase I study of AZD1775 with radiation therapy (RT) and temozolomide (TMZ) in patients with newly diagnosed glioblastoma (GBM) and evaluation of intratumoral drug distribution (IDD) in patients with recurrent GBM

2005

Background: The standard of care treatment for newly diagnosed GBM is maximal safe surgical resection followed by two DNA damaging agents, RT and TMZ. Cellular response to DNA damage involves checkpoints that halt the cell cycle to allow DNA repair. AZD1775 is an oral small molecular inhibitor of a nuclear tyrosine kinase Wee1, a key regulator of the G2/M checkpoint. Abrogation of the G2/M checkpoint prevents repair and pushes cells into mitosis with unrepaired DNA damage. AZD1775 was shown to enhance TMZ and RT effects in preclinical models. Methods: The Adult Brain Tumor Consortium 1202 trial (NCT01849146) is a phase I, open label, multicenter dose-finding study of AZD1775 in combination with standard RT and TMZ followed by an IDD study for patients undergoing surgery for recurrent GBM. The dose finding portion is comprised of two arms, one with AZD1775 given Monday through Friday during concurrent RT/TMZ and a second arm given with adjuvant TMZ qd x 5d/28d cycle. Each arm had standard 3+3 design. A combination cohort with both concurrent and adjuvant AZD1775 at MTD and analysis of PK/PD and IDD at MTD in patients undergoing surgery for recurrent GBM followed. Results: 51 patients enrolled in the dose finding arms. For the concurrent arm, the MTD was 200 mg. At 275 mg one patient had grade 3 fatigue and another had grade 4 thrombocytopenia and neutropenia. Two of 6 total patients enrolled at 200 mg experienced DLTs (grade 4 neutropenia and grade 3 ALT elevation). The MTD for the adjuvant arm was 425 mg as 1 of 6 patients had DLT (grade 4 decrease in ANC). At 500 mg, 2 of 3 patients experienced intolerable diarrhea despite prophylaxis. Enrollment in the combination cohort is completed and evaluation of safety is underway. The drug concentration in contrast enhancing and non-enhancing brain tumor was 4-8 x and 0.5-2.6 x greater than plasma, respectively for patients on IDD portion. Conclusions: The MTD for AZD1775 in combination with RT/TMZ is 200 mg qd M-F with concurrent RT/TMZ and 425 mg qd x 5d/28d cycle in combination with adjuvant TMZ. IDD and PK/PD analysis is ongoing to inform the decision to proceed to phase II testing. Clinical trial information: NCT01849146.

NCCTG N1174: Phase I/comparative randomized phase (Ph) II trial of TRC105 plus bevacizumab versus bevacizumab in recurrent glioblastoma (GBM) (Alliance)

2023

Background: TRC105 is a humanized antibody targeting CD105 (endoglin), a member of the TGFβ receptor superfamily. CD105 is expressed in glioma stem cells and circulating endothelial cells (CECs) in GBM patients (pts), increasing following VEGF inhibition. N1174 was conducted in recurrent bevacizumab (bev) naïve GBM pts to investigate the hypothesis that CD105 blockade+bev can delay development of bev resistance. Methods: After a ph I cohort (15 pts) established the ph II dose of TRC105 as 10 mg/kg IV over 4 hours every 7 days in combination with standard dose bev, the ph II trial used 1:1 randomization with 90% power and 0.10 type I error to detect a 3 month (mo) difference in progression-free survival (PFS) between the two arms. CECs including CD105 positive subsets were measured by flow cytometry at baseline and multiple time points. Results: Based on 101 evaluable ph II pts, there was no significant difference in PFS between TRC105+bev and bev only (2.9 vs 3.2 mo, respectively; HR=1.14, 95% CI 0.73-1.77, p=0.57), or overall survival (10.0 vs 7.4 mo; HR 1.02 95% CI 0.63-1.65, p=0.93). Response rate (complete or partial) was 12.2% (6/49) for TRC105+bev and 11.6% (5/43) for bev only. Overall incidence of grade (gr) 3+ toxicity was higher for TRC105+bev (67.3% vs 32.7%, p<0.001) mainly due to 14 pts with gr 3 anemia in the TRC105+bev arm vs 0 in the bev only pts. Gr 3+ non-heme toxicities were higher in pts receiving TRC105+bev vs bev only (50% vs 30.6%, p=0.07), mainly due to headache (6 vs 1 pts) and hyperglycemia (3 vs 0 pts). CECs remained stable in combination treated pts, suggesting a possible impact of the anti-CD105 blockade, but increased at progression in the bev only arm. There was no association between PFS and initial changes in CEC values, independent of treatment received. Conclusions: TRC105 plus bev did not prolong median PFS vs single agent bev in recurrent GBM pts, although it was associated with a non-significant prolongation of OS. These data and associated correlative analysis of CECs from study pts point against endoglin being a clinically significant factor for the development of bev resistance. Support: U10CA180821, U10CA180882. Clinical trial information: NCT01648348.

Treatment through progression with ofranogene obadenovec (VB-111), an anti-cancer viral therapy, significantly attenuates tumor growth in recurrent GBM: Individual phase 2 patient data

2055

Background: Ofranergene obadenovec (VB-111) is a viral cancer-therapy with a dual mechanism: vascular disruption and induction of a tumor directed immune response. Prolongation of overall survival (OS) has been shown in recurrent glioblastoma (rGBM) patients treated through progression with VB-111 in combination with bevacizumab (BEV) compared to historical controls and to patients with limited exposure (LE) to VB-111. Here we present individual patient tumor growth data. Methods: VB-111 was administered at 1x1013viral particles bimonthly until progression, followed by BEV standard of care (LE cohort). The protocol was amended to allow treatment through progression (TThP) with VB-111 bimonthly, with the addition of BEV 10mg/Kg biweekly, until further progression (TThP cohort). Tumor dimensions were assessed q2 months by MRI locally and by an independent central lab. The slope of the log tumor measurement over time was calculated for each patient, average slopes were compared across therapy groups using the Wilcoxon Rank Sum test. Results: 46 patients received up to 13 doses of VB-111. All started with VB-111 monotherapy. 22 were included in the LE cohort; 24 in the TThP cohort. Cohorts were comparable by measures of age, performance status, prior lines of therapy, baseline tumor dimensions and progression-free-survival. Spider diagrams demonstrate similar rapid tumor growth in both LE and TThP cohorts during the VB-111 monotherapy period (local site data; median % increase (MPI) per 30d: 14.8 vs 14.1, p = 0.98). In the TThP cohort, growth was attenuated after the 1stprogression, compared to the preceding VB-111 monotherapy period (MPI: 0.6 vs 14.1, p = 0.0032); responses were seen, including 2 complete responses (CR), one patient remaining in CR over 3 years. A similar attenuation was seen in central lab tumor measurements. Conclusions: Treatment through progression with VB-111 in combination with BEV induced durable tumor growth attenuation, which was associated with prolonged OS of 15 months in patients with rGBM. The GLOBE phase 3 randomized controlled trial of VB-111 in rGBM is currently underway. Clinical trial information: NCT01260506.

Individualized screening trial of innovative glioblastoma therapy (INSIGhT)

TPS2079

Background: Patient with glioblastoma (GBM) with unmethylated MGMT promoters derive limited benefit from temozolomide (TMZ) and have dismal outcome. Prioritizing the numerous available therapies and biomarkers for late stage testing requires an efficient clinical testing platform. INSIGhT (NCT02977780) is a biomarker-based, Bayesian adaptively randomized, multi-arm phase II platform screening trial for patients with newly diagnosed GBM and unmethylated MGMT promoters. Methods: INSIGhT compares experimental arms to a common control of standard concurrent TMZ and radiation therapy (RT) followed by adjuvant TMZ. The primary endpoint is overall survival (OS). Patients with newly diagnosed, unmethylated GBM that are IDH R132H mutation negative, and with genomic data available or who consent to whole exome sequencing through the ALLELE companion study for biomarker grouping are eligible. Two experimental arms consist of concurrent RT/TMZ followed by adjuvant neratinib (EGFR, HER2, and HER4 inhibitor) or abemaciclib CDK 4/6 inhibitor), respectively, in place of TMZ. The other experimental arm is CC-115 (TORC1/2 and DNA PK inhibitor), which replaces TMZ in both the concurrent and adjuvant phases. Biomarker groups include: EGFR + patients with EGFR amplification/mutation; PI3K + patients with PIK3CA mutation/amplification, PIK3R1 mutation, AKT3amplification, PIK3C2B > 1 copy gain, or PTEN dual loss; CDK: + patients with wild-type RB1 and CDK4 amplification, CDK6 amplification, or CDKN2A > 1 copy loss. Given the lack of pretrial biomarker data and the anticipated overlap of the groups, randomization will initially be equal. As the trial progresses, randomization probabilities will be adapted based on the Bayesian estimation of the probability of treatment impact on progression-free survival (PFS). These randomization probabilities can vary among the biomarker groups so predictive biomarkers will be identified and utilized if present. Treatment arms may drop due to low probability of treatment impact on OS, and new arms may be added. Experimental arms are compared only with control and should be thought of as discrete experimental questions, with INSIGhT being open to new investigators with proposed therapeutic hypotheses. Clinical trial information: NCT02977780.

Efficacy of dabrafenib (D) and trametinib (T) in patients (pts) with BRAF V600E–mutated anaplastic thyroid cancer (ATC)

6023

Background: ATC is a rare, aggressive malignancy with a dismal prognosis. Median overall survival (OS) is < 6 mo. Combined BRAF and MEK inhibition is efficacious in BRAF V600–mutated melanoma and lung cancer. One-fourth of ATCs harbor activating BRAF V600E mutations; thus, D (BRAF inhibitor) + T (MEK inhibitor) was evaluated as a treatment for pts with BRAF V600E–mutated ATC. Methods: In this phase 2, open-label trial (NCT02034110), pts with BRAF V600E mutations in 9 rare tumor types, including ATC, received continuous D (150 mg BID) + T (2 mg QD) until unacceptable toxicity, disease progression, or death. Eligible pts had advanced or metastatic cancer with no standard-of-care treatment options. The primary endpoint was investigator-assessed overall response rate (ORR). Secondary endpoints included duration of response (DOR), progression-free survival (PFS), OS, and safety. We report data from the ATC cohort. Results: 16 pts with BRAF V600E–mutated ATC had evaluable data with a median follow-up time of 47 wk (range 4-120 wk). BRAF V600E mutations were centrally confirmed in 15/16 pts. Median age was 72 y; all 16 pts had undergone prior tumor radiation and/or surgery and 6/16 pts (38%) had received ≥1 prior line of systemic therapy. Investigator-assessed confirmed ORR was 69% (11/16; 95% CI, 41%-89%), with 7/11 responses ongoing at the time of data cut. The Bayesian estimate of ORR was 69% (95% credible interval, 47%-87%) with a 100% probability that this ORR exceeded the 15% historical RR. Median DOR, PFS, and OS were not estimable due to insufficient progression and death events. Kaplan-Meier estimates of DOR, PFS, and OS at 12 mo were 90%, 79%, and 80%, respectively. The safety population comprised 100 pts enrolled in 7/9 histologies. Among all pts, 92% had an AE. Common AEs of any grade for all histologies were fatigue (38%), pyrexia (37%), and nausea (35%). In the ATC cohort, the most common grade 3/4 events were hyponatremia (19%), pneumonia (13%), and anemia (13%). Conclusions: D+T combination therapy significantly improved outcomes in ATC with a favorable safety profile. This regimen represents a clinically meaningful therapeutic advance for pts with advanced/metastatic BRAF V600–mutated ATC. Clinical trial information: NCT02034110.

Assessment of tumor hypoxia in BEV resistant GBM using FMISO 18F-PET and MRI

2045

Background: Glioblastoma (GBM) is the most common malignant brain tumor in adults, and is characterized by poor survival and marked resistance to treatment. Hypoxic volume is directly correlated with poor outcome in GBM, with structural and functional tumor vasculature changes regarded as a primary driver of tumor hypoxia. As part of an ongoing clinical trial with a hypoxia activated prodrug, we sought to explore the correlation between abnormal tumor vasculature and hypoxia in bevacizumab (BEV) resistant GBM. Methods: MRI and 18F-FMISO PET scans were acquired at study entry. The MRI protocols include standard anatomical sequences as well as Dynamic Susceptibility Contrast (DSC/perfusion) imaging. Enhancing tumor ROIs were determined from Delta T1 maps, non-enhancing tumor ROIs were obtained from FLAIR images, ratio between enhancing and non-enhancing volumes were calculated, values from standardized rCBV maps were extracted from corresponding enhancing ROIs. Decay correction was applied to18F-FMISO images and converted to SUV units. After registration to MR images, cerebellar regions were used as surrogates for blood activity. The FMISO images were then normalized to generate tissue to blood ratio (TB). A threshold of TB > 1.2 was used in discriminating the hypoxia volume (HV). Correlation between parameters was assessed using Pearson correlation. Results: 7 patients from University of Texas Health Science center and 7 patients from Dana-Farber Cancer Institute had evaluable MR and PET imaging. We compared MRI parameters (enhancing and non-enhancing tumor volumes, srCBV) with hypoxia (HV and maxSUV). There was a positive correlation between HV and enhancing volume (R = 0.732, p = 0.0029) as well as between HV and ratio (R = 0.644, p = 0.013. The correlation between other pairs were not statistically significant (HV vs srCBV: p = 0.862, T1 vs maxSUV p = 0.492, srCBV vs maxSUV: p = 0.393, ratio vs maxSUV = 0.178). Conclusions: The hypoxic volume following bevacizumab failure correlates with both the volume of enhancement and the fraction of enhancement within the mass. The clinical implications of this is being assessed in an ongoing phase 2 study. Clinical trial information: NCT02342379.

Angiogenesis inhibitors in tackling recurrent glioblastoma

INTRODUCTION

Despite aggressive multimodality treatment of glioblastoma, outcome remains poor and patients mostly die of local recurrences. Besides reoperation and occasionally reirradiation, systemic treatment of recurrent glioblastoma consists of alkylating chemotherapy (lomustine, temozolomide), bevacizumab and combinations thereof. Unfortunately, antiangiogenic agents failed to improve survival either as a monotherapy or in combination treatments. This review provides current insights into tumor-derived escape mechanisms and other areas of treatment failure of antiangiogenic agents in glioblastoma. Areas covered: We summarize the current literature on antiangiogenic agents in the treatment of glioblastoma, with a focus on recurrent disease. A literature search was performed using the terms 'glioblastoma', 'bevacizumab', 'antiangiogenic', 'angiogenesis', 'resistance', 'radiotherapy', 'chemotherapy' and derivations thereof. Expert commentary: New insights in glioma neoangiogenesis, increasing understanding of vascular pathway escape mechanisms, and upcoming immunotherapy approaches might revitalize the therapeutic potential of antiangiogenic agents against glioblastoma, although with a different treatment intention. The combination of antiangiogenic approaches with or without radiotherapy might still hold promise to complement the therapeutic armamentarium of fighting glioblastoma.

The Neurologic Assessment in Neuro-Oncology (NANO) scale: a tool to assess neurologic function for integration into the Response Assessment in Neuro-Oncology (RANO) criteria

Background

The Macdonald criteria and the Response Assessment in Neuro-Oncology (RANO) criteria define radiologic parameters to classify therapeutic outcome among patients with malignant glioma and specify that clinical status must be incorporated and prioritized for overall assessment. But neither provides specific parameters to do so. We hypothesized that a standardized metric to measure neurologic function will permit more effective overall response assessment in neuro-oncology.

Methods

An international group of physicians including neurologists, medical oncologists, radiation oncologists, and neurosurgeons with expertise in neuro-oncology drafted the Neurologic Assessment in Neuro-Oncology (NANO) scale as an objective and quantifiable metric of neurologic function evaluable during a routine office examination. The scale was subsequently tested in a multicenter study to determine its overall reliability, inter-observer variability, and feasibility.

Results

The NANO scale is a quantifiable evaluation of 9 relevant neurologic domains based on direct observation and testing conducted during routine office visits. The score defines overall response criteria. A prospective, multinational study noted a >90% inter-observer agreement rate with kappa statistic ranging from 0.35 to 0.83 (fair to almost perfect agreement), and a median assessment time of 4 minutes (interquartile range, 3-5).

Conclusion

The NANO scale provides an objective clinician-reported outcome of neurologic function with high inter-observer agreement. It is designed to combine with radiographic assessment to provide an overall assessment of outcome for neuro-oncology patients in clinical trials and in daily practice. Furthermore, it complements existing patient-reported outcomes and cognition testing to combine for a global clinical outcome assessment of well-being among brain tumor patients.

Feasibility, phase I, and phase II studies of tandutinib, an oral platelet-derived growth factor receptor-β tyrosine kinase inhibitor, in patients with recurrent glioblastoma

Background

Platelet-derived growth factor (PDGF) signaling is important in gliomagenesis and PDGF receptor-β is expressed on most endothelial cells in glioblastoma specimens.

Methods

We report the results of feasibility, phase I, and phase II studies of tandutinib (MLN518), an orally bioavailable inhibitor of type III receptor tyrosine kinases including PDGF receptor-β, Fms-like tyrosine kinase 3, and c-Kit in patients with recurrent glioblastoma.

Results

In an initial feasibility study, 6 patients underwent resection for recurrent glioblastoma after receiving tandutinib 500mg twice daily for 7 days. The mean ratio of tandutinib concentration in brain tumor-to-plasma was 13.1±8.9 in 4 of the 6 patients. In the phase I study, 19 patients were treated at 500, 600, and 700mg twice daily dose levels. The maximum tolerated dose was found to be 600mg twice daily, and 30 patients were treated with this dose in the phase II study. The trial was closed after interim analysis, as the prespecified goal of patients alive and progression-free survival at 6 months was not achieved. Biomarker studies suggested that tandutinib treatment could lead to vascular disruption rather than normalization, which was associated with rapid progression.

Conclusions

Tandutinib readily distributed into the brain following oral administration and achieved concentrations within the tumor that exceed the corresponding concentration in plasma. The phase II study was closed at interim analysis due to lack of efficacy, although this study was not enriched for glioblastomas with alterations of the PDGF pathway.

Modified Criteria for Radiographic Response Assessment in Glioblastoma Clinical Trials

Radiographic endpoints including response and progression are important for the evaluation of new glioblastoma therapies. The current RANO criteria was developed to overcome many of the challenges identified with previous guidelines for response assessment, however, significant challenges and limitations remain. The current recommendations build on the strengths of the current RANO criteria, while addressing many of these limitations. Modifications to the current RANO criteria include suggestions for volumetric response evaluation, use contrast enhanced T1 subtraction maps to increase lesion conspicuity, removal of qualitative non-enhancing tumor assessment requirements, use of the post-radiation time point as the baseline for newly diagnosed glioblastoma response assessment, and "treatment-agnostic" response assessment rubrics for identifying pseudoprogression, pseudoresponse, and a confirmed durable response in newly diagnosed and recurrent glioblastoma trials.

Leptomeningeal metastases: a RANO proposal for response criteria

Leptomeningeal metastases (LM) currently lack standardization with respect to response assessment. A Response Assessment in Neuro-Oncology (RANO) working group with expertise in LM developed a consensus proposal for evaluating patients treated for this disease. Three basic elements in assessing response in LM are proposed: a standardized neurological examination, cerebral spinal fluid (CSF) cytology or flow cytometry, and radiographic evaluation. The group recommends that all patients enrolling in clinical trials undergo CSF analysis (cytology in all cancers; flow cytometry in hematologic cancers), complete contrast-enhanced neuraxis MRI, and in instances of planned intra-CSF therapy, radioisotope CSF flow studies. In conjunction with the RANO Neurological Assessment working group, a standardized instrument was created for assessing the neurological exam in patients with LM. Considering that most lesions in LM are nonmeasurable and that assessment of neuroimaging in LM is subjective, neuroimaging is graded as stable, progressive, or improved using a novel radiological LM response scorecard. Radiographic disease progression in isolation (ie, negative CSF cytology/flow cytometry and stable neurological assessment) would be defined as LM disease progression. The RANO LM working group has proposed a method of response evaluation for patients with LM that will require further testing, validation, and likely refinement with use.

Phase II study of tivozanib, an oral VEGFR inhibitor, in patients with recurrent glioblastoma

Targeting tumor angiogenesis is a potential therapeutic strategy for glioblastoma because of its high vascularization. Tivozanib is an oral pan-VEGF receptor tyrosine kinase inhibitor that hits a central pathway in glioblastoma angiogenesis. We conducted a phase II study to test the effectiveness of tivozanib in patients with recurrent glioblastoma. Ten adult patients were enrolled and treated with tivozanib 1.5 mg daily, 3 weeks on/1 week off in 28-day cycles. Brain MRI and blood biomarkers of angiogenesis were performed at baseline, within 24-72 h of treatment initiation, and monthly thereafter. Dynamic contrast enhanced MRI, dynamic susceptibility contrast MRI, and vessel architecture imaging were used to assess vascular effects. Resting state MRI was used to assess brain connectivity. Best RANO criteria responses were: 1 complete response, 1 partial response, 4 stable diseases, and 4 progressive disease (PD). Two patients were taken off study for toxicity and 8 patients were taken off study for PD. Median progression-free survival was 2.3 months and median overall survival was 8.1 months. Baseline abnormal tumor vascular permeability, blood flow, tissue oxygenation and plasma sVEGFR2 significantly decreased and plasma PlGF and VEGF increased after treatment, suggesting an anti-angiogenic effect of tivozanib. However, there were no clear structural changes in vasculature as vessel caliber and enhancing tumor volume did not significantly change. Despite functional changes in tumor vasculature, tivozanib had limited anti-tumor activity, highlighting the limitations of anti-VEGF monotherapy. Future studies in glioblastoma should leverage the anti-vascular activity of agents targeting VEGF to enhance the activity of other therapies.

Abstract B12: Adding angiotensin-system inhibitors to anti-angiogenic therapy reduces vasogenic edema in newly diagnosed glioblastomas but not in recurrent disease

Introduction: Recent theoretical [1], pre-clinical [2] and human tumor data [3] suggest anti-hypertensives with an extracellular matrix-depleting effect improve vascular function by reducing the solid stress that can squeeze tumor vessels shut [4]. This work is contrasted by studies showing that certain matrix-depleting anti-hypertensives (angiotensin-II receptor blockers) are also associated with reduced peri-tumoral edema [5]. We here show that combined matrix-depleting and anti-angiogenic therapy does reduce vasogenic edema in newly diagnosed glioblastomas but not in recurrent disease and that the mechanisms of action are therefore not fully understood.

Methods: We retrospectively assessed data from 40 patients with newly diagnosed glioblastomas (nGBM) and 30 patients with recurrent glioblastomas (rGBM) receiving cediranib, an oral pan-VEGFR inhibitor, with- (NCT00662506) and without (NCT00305656) chemoradiation, respectively. Conventional, perfusion and vessel caliber MRI were performed at baseline and repeated weekly (nGBM) or monthly (rGBM) [6, 7]. Vasogenic edema was measured as the relative volume of peri-tumoral hyper T2-Fluid Attenuated Inversion Recovery (FLAIR) signal on the conventional MRIs. For nGBM, after cediranib onset, 12/40 patients received angiotensin II receptor blockers (Valsartan), β1 receptor antagonists (Atenolol) or angiotensin-converting enzyme inhibitors (Lisinopril), while 8/40 patients received calcium antagonists (Norvasc, Amlodipine) [3]. Similarly, for rGBM, 15/30 patients received Atenolol and 7/30 patients Norvasc.

Results: While angiotensin-system inhibitors (ASIs) significantly improved the perfused vessel fraction (% of tumor values &gt;½ the value of healthy tissue; Wilcoxon P&lt;0.05) and the relative small vessel fraction (&lt;½ the size of healthy tissue; Wilcoxon P&lt;0.01) for both cohorts, reduction of vasogenic edema was only observed in nGBM patients. Here, both cediranib alone and in combination with ASIs reduced the median relative vasogenic edema volume (82% and 54% over study period and compared to baseline values, respectively; Wilcoxon P&lt;0.05), but not for non-ASI calcium antagonists (96%). For rGBMs, cediranib alone reduced the median relative vasogenic edema volume (90%; P&lt;0.05), but not when adding ASIs. Instead, there was a trend towards reduced vasogenic edema with non-ASI calcium antagonists.

Conclusion: The potential anti-edema effect associated with ASI anti-hypertensives is an attractive feature for reduced administration of steroids in patients with glioblastoma. However, our data indicate that the matrix-depleting activity of some anti-hypertensives improves vascular function in both nGBMs and rGBMs [3], but only reduces vasogenic edema in the newly diagnosed setting [5]. Further studies to understand the mechanisms of benefit of ASIs in cancer are warranted.

References:

1: PNAS 2013;110:18632-37

2: Nat Commun 2013; 4, 2516

3: Proc AACR Annual Meeting 2016; p3975

4: PNAS 2012; 109, 15101-8

5: J Neurol. 2016; 263, 524-30

6: PNAS 2013; 110, 19059-64

7: Nat Med 2013; 19, 1178-83

Citation Format: Kyrre E. Emblem, Elizabeth R. Gerstner, A Gregory Sorensen, Bruce R. Rosen, Patrick Y. Wen, Tracy T. Batchelor, Rakesh K. Jain. Adding angiotensin-system inhibitors to anti-angiogenic therapy reduces vasogenic edema in newly diagnosed glioblastomas but not in recurrent disease. [abstract]. In: Proceedings of the AACR Special Conference on Engineering and Physical Sciences in Oncology; 2016 Jun 25-28; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2017;77(2 Suppl):Abstract nr B12.