Preclinical and clinical evaluation of Buparlisib (BKM120) in recurrent/refractory Central Nervous System Lymphoma

Central Nervous System (CNS) Lymphomas are aggressive brain tumors with limited treatment options. Targeting the phosphoinositide 3-kinase (PI3K) pathway yields promising responses across B-cell malignancies, but its therapeutic potential in CNS lymphomas remains unexplored. We present pre-clinical and clinical data on the pan-PI3K inhibitor Buparlisib in CNS lymphomas. In a primary CNS lymphoma-patient-derived cell line, we define the EC50. Four patients with recurrent CNS lymphoma were enrolled in a prospective trial. We evaluated Buparlisib plasma and cerebrospinal fluid pharmacokinetics, clinical outcomes, and adverse events. Treatment was well tolerated. Common toxicities include hyperglycemia, thrombocytopenia, and lymphopenia. The presence of Buparlisib in plasma and CSF was confirmed 2h post-treatment with a median CSF concentration below the EC50 defined in the cell line All four patients were evaluated for response and the median time to progression was 39 days. Buparlisib monotherapy did not lead to meaningful responses and the trial was prematurely stopped.Clinical Trial Registration: NCT02301364.

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).

Alliance A071401: Phase II Trial of Focal Adhesion Kinase Inhibition in Meningiomas With Somatic NF2 Mutations

PURPOSE

Patients with progressive or recurrent meningiomas have limited systemic therapy options. Focal adhesion kinase (FAK) inhibition has a synthetic lethal relationship with NF2 loss. Given the predominance of NF2 mutations in meningiomas, we evaluated the efficacy of GSK2256098, a FAK inhibitor, as part of the first genomically driven phase II study in recurrent or progressive grade 1-3 meningiomas.

PATIENTS AND METHODS

Eligible patients whose tumors screened positively for NF2 mutations were treated with GSK2256098, 750 mg orally twice daily, until progressive disease. Efficacy was evaluated using two coprimary end points: progression-free survival at 6 months (PFS6) and response rate by Macdonald criteria, where PFS6 was evaluated separately within grade-based subgroups: grade 1 versus 2/3 meningiomas. Per study design, the FAK inhibitor would be considered promising in this patient population if either end point met the corresponding decision criteria for efficacy.

RESULTS

Of 322 patients screened for all mutation cohorts of the study, 36 eligible and evaluable patients with NF2 mutations were enrolled and treated: 12 grade 1 and 24 grade 2/3 patients. Across all grades, one patient had a partial response and 24 had stable disease as their best response to treatment. In grade 1 patients, the observed PFS6 rate was 83% (10/12 patients; 95% CI, 52 to 98). In grade 2/3 patients, the observed PFS6 rate was 33% (8/24 patients; 95% CI, 16 to 55). The study met the PFS6 efficacy end point both for the grade 1 and the grade 2/3 cohorts. Treatment was well tolerated; seven patients had a maximum grade 3 adverse event that was at least possibly related to treatment with no grade 4 or 5 events.

CONCLUSION

GSK2256098 was well tolerated and resulted in an improved PFS6 rate in patients with recurrent or progressive NF2-mutated meningiomas, compared with historical controls. The criteria for promising activity were met, and FAK inhibition warrants further evaluation for this patient population.

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.

CTNI-64. FOCUSED ULTRASOUND MEDIATED BLOOD-BRAIN BARRIER PENETRANCE TO ENABLE CELL-FREE DNA (CFDNA) AS A LIQUID BIOPSY IN RECURRENT PRIMARY BRAIN TUMORS

The WHO recommends molecular characterization of CNS tumors. (Louis et al., 2021, 2016). However, many patients at diagnosis and recurrence, do not have tissue accessible for genomics. Blood-based liquid biopsy tests, provide a non-invasive means to obtain genomic data. Liquid biopsy tests are widely adopted to avoid side effects related to invasive biopsies in other solid tumors. However, for primary brain tumors, most patients have cfDNA concentrations below the Limit-of-Detection (LOD) of the tests. The primary contributor to low yield is the blood-brain barrier (BBB) which prevents free passage of tumor analytes into the circulatory system. BBB opening mediated by Focused Ultrasound (FUS) oscillation of microbubbles (MB) has led to an increase of tumor-derived circulating biomarkers in pre-clinical models and in human GBM (Zhu et al 2018, Meng et al 2021). Cordance Medical is developing a non-invasive, portable FUS platform that can enable clinic-based BBB opening treatments. The Cordance device utilizes three transducer types, a Type 1 transducer for non-invasive BBB opening localization obtains Doppler images of the Circle-of-Willis through the temporal lobe. The Doppler images align to the existing MRI using CoW as the fiducial. An array of Type 2 transducers for BBB opening to generate sufficient acoustic pressure to safely oscillate MBs to open the BBB. Finally, Type 3 transducers for safety monitoring receive echo signals from the MBs. Signals are analyzed for harmonic content which enables safety monitoring. The primary endpoint, we will be examining the Cordance platform's ability to increase the concentration of circulating biomarkers following a safe BBB opening. We will recruit patients with recurrent GBM. Patients will receive a baseline blood draw, a BBB opening treatment with the Cordance device, followed by a blood draw after the treatment. Liquid biopsy tests to be examined include the MSK ACCESS test and tumor-informed ddPCR MRD test.

Safety, tolerability and efficacy of agonist anti-CD27 antibody (varlilumab) administered in combination with anti-PD-1 (nivolumab) in advanced solid tumors

BACKGROUND

Phase 1/2 dose-escalation and expansion study evaluating varlilumab, a fully human agonist anti-CD27 mAb, with nivolumab in anti-PD-1/L1 naïve, refractory solid tumors.

METHODS

Phase 1 evaluated the safety of varlilumab (0.1-10 mg/kg) with nivolumab (3 mg/kg) administered once every 2 weeks. Phase 2 evaluated varlilumab regimens (3 mg/kg once every 2 weeks, 3 mg/kg once every 12 weeks, and 0.3 mg/kg once every 4 weeks) with nivolumab 240 mg once every 2 weeks in tumor-specific cohorts. Primary objective was safety; key clinical endpoints included objective response rate (ORR) and overall survival rate at 12 months (OS12) (glioblastoma (GBM) only). Exploratory objectives included determination of effects on peripheral blood and intratumoral immune signatures.

RESULTS

175 patients were enrolled (36 in phase 1 and 139 in phase 2). Phase 1 dose-escalation proceeded to the highest varlilumab dose level without determining a maximum tolerated dose. In phase 2, ORR were ovarian 12.5%, squamous cell carcinoma of the head and neck 12.5%, colorectal cancer 5%, and renal cell carcinoma 0%; GBM OS12 was 40.9%. Increased tumor PD-L1 and intratumoral T cell infiltration were observed in ovarian cancer patients, with increases of ≥5% associated with better progression-free survival. The most common treatment related adverse events were fatigue (18%), pruritus (16%), and rash (15%).

CONCLUSION

Varlilumab and nivolumab were well tolerated, without significant toxicity beyond that expected for each agent alone. Clinical activity was observed in patients that are typically refractory to anti-PD-1 therapy, however, overall was not greater than expected for nivolumab monotherapy. Treatment was associated with proinflammatory changes in the tumor microenvironment, particularly in ovarian cancer where the changes were associated with better clinical outcomes.

TRIAL REGISTRATION NUMBER

NCT02335918.

Circulating Immune Cell and Outcome Analysis from the Phase II Study of PD-L1 Blockade with Durvalumab for Newly Diagnosed and Recurrent Glioblastoma

PURPOSE

PD-L1 is upregulated in glioblastoma and supports immunosuppression. We evaluated PD-L1 blockade with durvalumab among glioblastoma cohorts and investigated potential biomarkers.

PATIENTS AND METHODS

MGMT unmethylated newly diagnosed patients received radiotherapy plus durvalumab (cohort A; n = 40). Bevacizumab-naïve, recurrent patients received durvalumab alone (cohort B; n = 31) or in combination with standard bevacizumab (cohort B2; n = 33) or low-dose bevacizumab (cohort B3; n = 33). Bevacizumab-refractory patients received durvalumab plus bevacizumab (cohort C; n = 22). Primary endpoints were: OS-12 (A), PFS-6 (B, B2, B3), and OS-6 (C). Exploratory biomarkers included: a systematic, quantitative, and phenotypic evaluation of circulating immune cells; tumor mutational burden (TMB); and tumor immune activation signature (IAS).

RESULTS

No cohort achieved the primary efficacy endpoint. Outcome was comparable among recurrent, bevacizumab-naïve cohorts. No unexpected toxicities were observed. A widespread reduction of effector immune cell subsets was noted among recurrent patients compared with newly diagnosed patients that was partially due to dexamethasone use. A trend of increased CD8+Ki67+ T cells at day 15 was noted among patients who achieved the primary endpoint and were not on dexamethasone. Neither TMB nor IAS predicted outcome.

CONCLUSIONS

Patients with recurrent glioblastoma have markedly lower baseline levels of multiple circulating immune cell subsets compared with newly diagnosed patients. An early increase in systemic Ki67+CD8+ cells may warrant further evaluation as a potential biomarker of therapeutic benefit among patients with glioblastoma undergoing checkpoint therapy. Dexamethasone decreased immune cell subsets. PD-L1 blockade and combination with standard or reduced dose bevacizumab was ineffective.

Brain radiotherapy, tremelimumab-mediated CTLA-4-directed blockade +/- trastuzumab in patients with breast cancer brain metastases

Breast cancer brain metastases (BCBM) are a common and devastating complication of metastatic breast cancer with conventional systemic therapies demonstrating limited effectiveness. Consequently, radiotherapy (RT) ± surgery remains the cornerstone of BCBM management. Because preclinical and clinical evidence indicate that immune checkpoint blockade (ICB) may synergize with RT to promote systemic tumor regression, we explored the safety and efficacy of RT and concurrent tremelimumab-mediated cytotoxic T-lymphocyte associated protein 4 (CTLA-4) ICB with tremelimumab ± HER2-directed therapy with trastuzumab for BCBM. Eligible patients had BCBM indicated for brain RT. A Simon two-stage design was adopted to evaluate the efficacy of tremelimumab and RT in 20 patients with human epidermal growth factor receptor normal (HER2−) BCBM. The safety of concurrent RT, tremelimumab, and trastuzumab was evaluated in a cohort of 6 HER2+ patients. The primary endpoint was 12-week non-central nervous system (CNS) disease control rate (DCR). Secondary endpoints included safety, survival, and CNS response. Exploratory correlatives included characterization of peripheral blood immune responses among exceptional responders. Tremelimumab plus RT ± trastuzumab was tolerated with no treatment-related grade 4 adverse events reported. The 12-week non-CNS DCR was 10% (2/20) in the HER2− cohort and 33% (2/6) in the HER2+ cohort. One patient with HER2+ disease experienced a durable partial response with evidence of peripheral T-cell activation. Thus, tremelimumab and RT ± trastuzumab was tolerated. Although modest clinical activity was observed in the HER2- efficacy cohort, encouraging responses were observed in the HER2+ safety cohort. Consequently, a trial to determine efficacy in HER2+ BCBM is planned.

Clinical Trial Registration Number: NCT02563925.

CTNI-55. THE CDK4/6 INHIBITOR ABEMACICLIB IN PATIENTS WITH RECURRENT MENINGIOMA AND OTHER PRIMARY CNS TUMORS

BACKGROUND

Medical therapies for recurrent brain tumors are limited. Abemaciclib is a small molecule CDK4/6 inhibitor that has demonstrated antitumor activity in multiple cancer types and crosses the blood-brain barrier.

METHODS

We conducted a phase II trial of single-agent abemaciclib in patients with recurrent primary brain tumors utilizing a novel CNS basket trial design with multiple tumor types accrued to separate cohorts including patients with recurrent IDH-wildtype gliomas (Cohort A), any recurrent gliomas requiring cytoreductive surgery (Cohort B), and any other recurrent primary brain tumors (Cohort C) including IDH-mutant gliomas, meningiomas, and other tumor types. In all patients, abemaciclib was administered orally at 200mg twice daily for each 28-day cycle. In cohort B abemaciclib was administered 4-7 days prior to surgery then resumed after recovery. Neuroimaging disease assessments were performed every two cycles. Cohorts were individually assessed for efficacy, tumoral molecular characteristics, and exploratory biomarker analyses. Next generation sequencing was performed on patients who had prior surgery.

RESULTS

To date, a total of 61 patients have enrolled and initiated treatment with abemaciclib. Cohort A enrolled 9 patients with IDH-wildtype WHO grade II and III astrocytomas. Cohort B enrolled 10 patients with astrocytomas of varying IDH-status. Cohort C is a diverse group of 42 patients including 22 treatment-refractory meningiomas, 10 IDH-mutant gliomas (5 astrocytomas, 5 oligodendrogliomas), 3 ependymomas, 3 primary CNS lymphomas, 2 pituitary tumors, 1 glioneuronal rosette forming tumor, and 1 diffuse midline glioma. A total of 7 grade 3 toxicities occurred in 6 patients: fatigue (3), neutropenia (2), colitis (1) and seizure (1); no grade 4 toxicities occurred.

CONCLUSIONS

We present the results of a novel CNS basket trial looking at the efficacy of abemaciclib across multiple recurrent primary brain tumors. Efficacy results will be presented, highlighting an update on promising results in the 22 patients with recurrent meningiomas.

CTNI-40. EVALUATING FEASIBILITY AND EFFICIENCY OF PHASE II ADAPTIVE PLATFORM TRIAL DESIGNS BASED ON THE INDIVIDUALIZED SCREENING TRIAL OF INNOVATIVE GLIOBLASTOMA THERAPY (INSIGhT) EXPERIENCE

BACKGROUND

The Individualized Screening Trial of Innovative Glioblastoma Therapy (INSIGhT) is a phase II platform trial with Bayesian adaptive randomization and deep genomic profiling to more efficiently test experimental agents in newly diagnosed glioblastoma and to prioritize therapies for late-stage testing.

METHODS

In the ongoing INSIGhT trial, patients with newly diagnosed MGMT-unmethylated glioblastoma are randomized to the control arm or one of three experimental therapy arms (CC-115, abemaciclib, and neratinib). The control arm therapy is radiotherapy with concomitant and adjuvant temozolomide, and primary endpoint is overall survival. Randomization has been adapted based on Bayesian estimation of biomarker-specific probability of treatment impact on progression-free survival (PFS). All tumors undergo detailed molecular sequencing, and this is facilitated with the companion ALLELE protocol. To evaluate feasibility of this approach, we assessed the status of this ongoing trial.

RESULTS

Since INSIGhT was activated 4.3 years ago, it has expanded to include 12 sites across the United States. A total of 247 patients have been enrolled. Randomization probabilities have been repeatedly adjusted over time based upon early PFS results to alter the randomization ratio from standard 1:1:1:1 randomization. All three arms have completed accrual and efficacy estimates are available based upon comparison to the common control arm in context of relevant biomarkers. There are 87 patients alive and in follow-up, and there are ongoing plans to add additional arms to evaluate further treatments in the future.

CONCLUSION

The INSIGhT trial demonstrates that a multi-center Bayesian adaptive platform trial is a feasible and effective approach to help prioritize therapies and biomarkers for newly diagnosed GBM. The trial has maintained robust accrual, and the simultaneous testing of multiple agents, sharing a common control arm and adaptive randomization serve as features to increase trial efficiency relative to traditional clinical trial designs.

CTNI-05. PRELIMINARY RESULTS OF THE NERATINIB ARM IN THE INDIVIDUALIZED SCREENING TRIAL OF INNOVATIVE GLIOBLASTOMA THERAPY (INSIGHT): A PHASE II PLATFORM TRIAL USING BAYESIAN ADAPTIVE RANDOMIZATION

BACKGROUND

EGFR is amplified in over 50% of glioblastoma and 20-30% have EGFRvIII mutations. Neratinib is a potent inhibitor of EGFR/HER2 approved for metastatic HER2+ breast cancer. To efficiently evaluate the potential impact of neratinib on overall survival (OS) in newly-diagnosed glioblastoma and to simultaneously develop information regarding potential genomic biomarker associations, neratinib was included as an arm on the Individualized Screening Trial of Innovative Glioblastoma Therapy (INSIGhT) trial. INSIGhT is a phase II platform trial using response adaptive randomization and deep genomic profiling to more efficiently test experimental agents in MGMT unmethylated glioblastoma and accelerate identification of novel therapies for phase III testing. Initial randomization was equal between neratinib, control, and two other experimental arms but subsequent randomization was adapted based on efficacy as determined by progression-free survival (PFS). We report preliminary results for the neratinib arm.

METHODS

Patients with newly diagnosed MGMT-unmethylated glioblastoma were randomized to receive either radiotherapy with concomitant and adjuvant temozolomide or standard radiochemotherapy followed by adjuvant neratinib (240 mg daily). Treatment continued until progression or development of unacceptable toxicities. The primary endpoint was OS. Association between neratinib efficacy and EGFR amplification was also investigated.

RESULTS

There were 144 patients (70 control; 74 neratinib). Neratinib was reasonably well-tolerated with no new toxicity signals identified. PFS was compared (HR 0.84; p=0.38, logrank test – not significant) between the neratinib (median 6.05 months) and control (median 5.82 months) arms. For patients EGFR pathway activation the PFS HR was 0.53 (p-value=0.03 – significant, median PFS: neratinib, 6.21 months, control, 5.26 months). However, there was no significant improvement in OS in EGFR amplified/mutated patients (HR 1.05; p-value 0.87) between neratinib (median 14.2) compared to the control arm (median 14.6).

CONCLUSION

Neratinib prolonged PFS in the EGFR positive subpopulation but there was no overall PFS benefit, or any OS improvement.

Leptomeningeal disease in pancreas ductal adenocarcinoma: A manifestation of longevity

BACKGROUND

/Objectives: Pancreatic adenocarcinoma (PDAC) metastatic to the leptomeninges is a rare and lethal event. Leptomeningeal disease (LMD) research is limited in PDAC, and insights into clinical descriptors, possible disease predictors, and treatment strategies is necessitated.

METHODS

Memorial Sloan Kettering databases were queried with Institutional Review Board approval to identify patients with LMD and PDAC treated between January 2000 and June 2020. Medical record review was used to abstract clinical, genomic, pathologic, and radiographic data. Overall survival was calculated from date of PDAC diagnosis to date of death. Previously published literature on LMD from PDAC was reviewed.

RESULTS

Four patients with LMD from PDAC were identified, two males and two females. Age at diagnosis ranged from 57 to 68 years. All four patients had predominant lung metastasis and a relatively low burden of intra-abdominal disease. Somatic testing indicated alterations typical of PDAC and no PDAC defining pathogenic germline mutations were identified. An extended clinical course prior to LMD diagnosis was observed in all patients, ranging from 16 to 148 months. Upon diagnosis of LMD, three patients elected for supportive care and one patient received a limited course of craniospinal radiation. The median survival following diagnosis of LMD was 1.6 months (range 0.5-2.8 months).

CONCLUSIONS

LMD from PDAC is a rare occurrence that may be more frequent in patients with lung metastasis and/or a more indolent clinical course. Following diagnosis of LMD, prognosis is poor, and survival is short. New treatment strategies for this manifestation of PDAC are needed.

Randomized Phase II and Biomarker Study of Pembrolizumab plus Bevacizumab versus Pembrolizumab Alone for Patients with Recurrent Glioblastoma

PURPOSE

VEGF is upregulated in glioblastoma and may contribute to immunosuppression. We performed a phase II study of pembrolizumab alone or with bevacizumab in recurrent glioblastoma.

PATIENTS AND METHODS

Eighty bevacizumab-naïve patients with recurrent glioblastoma were randomized to pembrolizumab with bevacizumab (cohort A, n = 50) or pembrolizumab monotherapy (cohort B, n = 30). The primary endpoint was 6-month progression-free survival (PFS-6). Assessed biomarkers included evaluation of tumor programmed death-ligand 1 expression, tumor-infiltrating lymphocyte density, immune activation gene expression signature, and plasma cytokines. The neurologic assessment in neuro-oncology (NANO) scale was used to prospectively assess neurologic function.

RESULTS

Pembrolizumab alone or with bevacizumab was well tolerated but of limited benefit. For cohort A, PFS-6 was 26.0% [95% confidence interval (CI), 16.3-41.5], median overall survival (OS) was 8.8 months (95% CI, 7.7-14.2), objective response rate (ORR) was 20%, and median duration of response was 48 weeks. For cohort B, PFS-6 was 6.7% (95% CI, 1.7-25.4), median OS was 10.3 months (95% CI, 8.5-12.5), and ORR was 0%. Tumor immune markers were not associated with OS, but worsened OS correlated with baseline dexamethasone use and increased posttherapy plasma VEGF (cohort A) and mutant IDH1, unmethylated MGMT, and increased baseline PlGF and sVEGFR1 levels (cohort B). The NANO scale contributed to overall outcome assessment.

CONCLUSIONS

Pembrolizumab was ineffective as monotherapy and with bevacizumab for recurrent glioblastoma. The infrequent radiographic responses to combinatorial therapy were durable. Tumor immune biomarkers did not predict outcome. Baseline dexamethasone use and tumor MGMT warrant further study as potential biomarkers in glioblastoma immunotherapy trials.

NCOG-44. NEUROLOGIC ASSESSMENT IN NEURO-ONCOLOGY (NANO) SCALE IN A PHASE II STUDY OF PEMBROLIZUMAB OR PEMBROLIZUMAB PLUS BEVACIZUMAB IN PATIENTS WITH RECURRENT GLIOBLASTOMA

PURPOSE

The neurologic assessment in neuro-oncology (NANO) scale was developed as a standardized metric to objectively measure neurologic function in brain tumor patients to complement radiographic assessment in defining overall outcome. A multicenter, phase 2 study of pembrolizumab with or without bevacizumab in patients with recurrent glioblastoma incorporated the NANO scale as an exploratory endpoint.

METHODS

Neurologic examination was evaluated at baseline and MRI assessments using the NANO scale until patients came off study. Statistical descriptive data analysis was performed using R (version 3.4.3). Correlation analysis utilized Fisher’s exact test.

RESULTS

NANO compliance rate was 94% in 80 patients accrued on the study. Of the 80 patients, 7 were missing NANO at baseline visit and were excluded from analysis for NANO response criteria. Fifteen patients did not have end of treatment NANO evaluation. Of 73 patients, 35 (48%) had a normal neurologic examination at baseline by NANO. Strength and language accounted for the majority of changes in neurologic function over the course of study treatment. Eighteen patients (25%) had neurologic progression by NANO, of whom 2 did not have concurrent radiographic progression. Three patients (pembrolizumab plus bevacizumab cohort) had a neurologic response associated with stable disease on MRI. NANO assessment prior to initiation of cycle 3 correlated with RANO response (p=0.011), change in KPS (p=0.002) and dexamethasone requirement (p=0.007) while those with NANO progression at this assessment had worse overall survival (291 vs 324 days), but this trend did not achieve statistical significance (p=0.2).

CONCLUSIONS

Evaluation of neurologic function by NANO scale was feasible in a multicenter prospective study in patients with GBM with a high compliance rate. The NANO scale objectively tracked stable neurologic function in most patients throughout the trial period and was associated with a trend for survival.

CTNI-11. CC-115 IN NEWLY DIAGNOSED MGMT UNMETHYLATED GLIOBLASTOMA IN THE INDIVIDUALIZED SCREENING TRIAL OF INNOVATIVE GLIOBLASTOMA THERAPY (INSIGHT): A PHASE II RANDOMIZED BAYESIAN ADAPTIVE PLATFORM TRIAL

BACKGROUND

CC-115 is an oral, CNS-penetrant, selective inhibitor of mammalian target of rapamycin kinase (mTOR) and deoxyribonucleic acid-dependent protein kinase (DNA-PK). Both targets are important in glioblastoma; PI3K/Akt/mTOR signaling is hyperactive in most glioblastomas, and DNA-PK is integral to repair of radiotherapy-mediated DNA damage. To investigate CC-115 in newly diagnosed glioblastoma and explore potential genomic biomarker associations, CC-115 was evaluated in the Individualized Screening Trial of Innovative Glioblastoma Therapy (INSIGhT) trial, an adaptive platform trial designed to efficiently test experimental agents.

METHODS

Adults with newly diagnosed MGMT-unmethylated glioblastoma, with genomic data available, are eligible for this ongoing trial. Patients are adaptively randomized to one of several experimental arms or the control arm: standard radiotherapy with concurrent and adjuvant temozolomide. The primary endpoint is overall survival (OS). Patients randomized to CC-115 (10mg po BID) received it concurrently with radiotherapy and as adjuvant monotherapy. As the first in-human use of CC-115 with radiation, a safety lead-in 3 + 3 design was used.

RESULTS

Twelve patients were randomized to CC-115; seven patients had possible treatment-related CTCAE grade > 3 toxicity, including four pre-specified dose-limiting toxicities: liver function abnormality (n=1), hyperlipidemia (n=1), lipase elevation (n=1) and cerebral edema (n=1). There was no significant difference in progression-free survival (PFS, median 4.2 months [CC-115] vs. 5.2 months, p=0.9) or OS (median 10.1 months [CC-115] vs. 14.5 months, p=0.9) compared to the 50 patients randomized to the control arm. Based on early PFS results, randomization probability to CC-115 decreased from 25% to < 10% at time of the trial arm closure.

CONCLUSION

Concurrent and adjuvant CC-115 was associated with toxicity and failed to improve PFS or OS. The INSIGhT trial design allowed for more efficient testing of CC-115, decreasing patients and resources allocated to a therapy that was discontinued due to concerns about toxicity and unfavorable risk-to-benefit ratio.

CTNI-12. PRELIMINARY RESULTS OF THE ABEMACICLIB ARM IN THE INDIVIDUALIZED SCREENING TRIAL OF INNOVATIVE GLIOBLASTOMA THERAPY (INSIGHT): A PHASE II PLATFORM TRIAL USING BAYESIAN ADAPTIVE RANDOMIZATION

BACKGROUND

The cyclin D-CDK4/6-Rb pathway is activated in most glioblastomas. Abemaciclib is a potent CDK4/6 inhibitor with good brain penetration approved for ER/PR/HER2- breast cancer. In order to efficiently evaluate the potential impact of abemaciclib on overall survival (OS) in newly diagnosed glioblastoma and to simultaneously develop information regarding potential genomic biomarker associations, abemaciclib was included as an arm on the Individualized Screening Trial of Innovative Glioblastoma Therapy (INSIGhT) trial. INSIGhT is a phase II platform trial using response adaptive randomization and deep genomic profiling to more efficiently test experimental agents in MGMT unmethylated glioblastoma and potentially accelerate identification of novel therapies for phase III testing. Initial randomization was equal between abemaciclib, control, and two other experimental arms but subsequent randomization was adapted based on efficacy as determined by progression-free survival (PFS). Ineffective arms were discontinued and new arms added by protocol amendment. We report preliminary results for the abemaciclib arm which has completed accrual.

METHODS

Patients with newly diagnosed MGMT-unmethylated glioblastoma were randomized to receive either radiotherapy with concomitant and adjuvant temozolomide at standard doses or standard radiochemotherapy followed by adjuvant abemaciclib (150–200 mg orally BID) without temozolomide. Treatment continued until progression or development of unacceptable toxicities. The primary endpoint was OS. Association between abemaciclib efficacy and cyclin D-CDK4/6-Rb pathway genomic alterations was also investigated.

RESULTS

There were 123 patients (50 control; 73 treated with abemaciclib). Abemaciclib was generally well-tolerated with no new toxicity signals identified. PFS was significantly longer (p=0.03, logrank test) with abemaciclib (median 6.31 months 95% CI [5.29, 8.18]) compared to the control arm (5.16 months 95% CI [4.37, 6.28]). 28/50 control and 36/73 abemaciclib patients remain alive.

CONCLUSION

Preliminary analysis suggests that abemaciclib increases PFS compared to control. Updated toxicity, PFS and survival data and potential genomic biomarker associations will be presented.

CTIM-32. PHASE II AND BIOMARKER STUDY OF PEMBROLIZUMAB OR PEMBROLIZUMAB PLUS BEVACIZUMAB FOR RECURRENT GLIOBLASTOMA PATIENTS

PURPOSE

Vascular endothelial growth factor (VEGF) is upregulated in glioblastoma and may contribute to immunosuppression. We performed a phase 2 study of pembrolizumab, a programmed death-1 (PD-1) blocking antibody alone or with the anti-VEGF antibody bevacizumab in recurrent glioblastoma with detailed analyses of biomarkers and patient neurologic function.

METHODS

Eighty bevacizumab-naive, recurrent glioblastoma patients were randomized to receive pembrolizumab with bevacizumab (cohort A, n=50) or pembrolizumab monotherapy (cohort B, n=30). The primary endpoint was six-month progression-free survival (PFS-6). Exploratory endpoints included evaluation of tumor PD-L1 expression, TIL density, immune activation gene expression signature and plasma cytokines with outcome. Changes in neurologic function were prospectively assessed using the Neurologic Assessment in Neuro-Oncology (NANO) scale.

RESULTS

Pembrolizumab alone or with bevacizumab was well tolerated but of limited benefit. For cohort A, PFS-6 was 26.0% (95% CI: 16.3, 41.5), median OS was 8.8 months (95% CI: 7.7, 14.2), ORR was 20% and median duration of response was 48 weeks. For cohort B, PFS-6 was 6.7% (95% CI: 1.7, 25.4), median OS was 10.3 months (95% CI: 8.5, 12.5) and ORR was 0%. Factors associated with worsened OS included baseline dexamethasone use and increased post-therapy plasma VEGF (cohort A) and wild-type IDH1, unmethylated MGMT and increased baseline PlGF and sVEGFR1 levels (cohort B), but tumor immune markers were not informative. The NANO scale effectively predicted neurologic function.

CONCLUSIONS

Although well tolerated, pembrolizumab was ineffective both as monotherapy and with bevacizumab for recurrent glioblastoma. Nonetheless, radiographic responses to combinatorial therapy were durable. Baseline dexamethasone use and plasma cytokines but not tumor immunologic biomarkers were associated with outcome. Neurologic function evaluated by the NANO scale contributed to outcome assessment.

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.

Management of Central Nervous System Tumors

Meningiomas represent a full spectrum of tumors that are the most common type of brain tumor in adults. Although most are benign, recent research has shown that the recurrence rate is high, especially for WHO grades 2 and 3, and overall survival is poor for these grades. Treatment is evolving, and recently sunitinib and bevacizumab have shown promise compared with historical treatments. However, more research is needed to identify better treatments for meningiomas. Treatment of brain metastases is another evolving field. Studies suggest that stereotactic radiosurgery is preferable to whole-brain radiation therapy and that immune checkpoint inhibitors and therapies targeted to the T790M mutation and ALK can improve outcomes in patients with non-small cell lung cancer and brain metastases.

Proposed response assessment and endpoints for meningioma clinical trials: report from the Response Assessment in Neuro-Oncology Working Group

No standard criteria exist for assessing response and progression in clinical trials involving patients with meningioma, and there is no consensus on the optimal endpoints for trials currently under way. As a result, there is substantial variation in the design and response criteria of meningioma trials, making comparison between trials difficult. In addition, future trials should be designed with accepted standardized endpoints. The Response Assessment in Neuro-Oncology Meningioma Working Group is an international effort to develop standardized radiologic criteria for treatment response for meningioma clinical trials. In this proposal, we present the recommendations for response criteria and endpoints for clinical trials involving patients with meningiomas.

Value of [18F]-FDG positron emission tomography in patients with recurrent glioblastoma receiving bevacizumab

BACKGROUND

Treatment of recurrent glioblastoma (GBM) with bevacizumab can induce MRI changes that confound the determination of progression. We sought to determine the value of [18F]-fluorodeoxyglucose (FDG) positron emission tomography (PET) in GBM patients receiving bevacizumab at the time of suspected progression and, thereby, its utility as a potential prognostic adjunct in progressive disease.

METHODS

This retrospective study included patients who underwent brain FDG PET within 4 weeks of receiving bevacizumab for recurrent GBM with suspected progression. Volumes-of-interest were placed over the reference lesion with measurement of maximum standardized uptake value (SUVmax), peak standardized uptake value (SUVpeak), metabolic tumor volume, total lesion glycolysis (TLG), and tumor-to-normal contralateral white matter ratios (TNR-WM). Tumors were additionally categorized as non-avid or avid based on qualitative FDG uptake. Associations between baseline variables and overall survival (OS) were examined using univariable and multivariable Cox proportional hazards regression, with P < .05 considered significant.

RESULTS

Thirty-one patients were analyzed. Qualitative FDG uptake was significantly associated with OS (P = .03), with a median OS of 9.0 months in non-avid patients versus 4.5 months in avid patients. SUVmax, SUVpeak, TNR-WM, and TLG were significantly associated with OS (P < .001, TLG: P = .009). FDG avidity and SUVmax remained significantly associated with OS (P = .046 and .048, respectively) in the multivariable analysis including age, KPS, and MGMT status. Dichotomizing patients using an SUVmax cutoff of 15.3 was associated with OS (adjusted P = .048).

CONCLUSION

FDG PET is a promising imaging tool to further stratify prognosis in recurrent GBM patients on antiangiogenic therapy.

DCE-MRI perfusion predicts pseudoprogression in metastatic melanoma treated with immunotherapy

PURPOSE

It can be challenging to differentiate pseudoprogression from progression. We assessed the ability of dynamic contrast enhanced T1 MRI (DCE-MRI) perfusion to identify pseudoprogression in melanoma brain metastases.

METHODS

Patients with melanoma brain metastases who underwent immunotherapy and DCE-MRI were identified. Enhancing lesions ≥  5mm in diameter on DCE-MRI and that were new or increased in size between a week from beginning the treatment, and a month after completing the treatment were included in the analysis. The 90th percentiles of rVp and rKtrans and the presence or absence of hemorrhage were recorded. Histopathology served as the reference standard for pseudoprogression. If not available, pseudoprogression was defined as neurological and radiographic stability or improvement without any new treatment for ≥ 2 months.

RESULTS

Forty-four patients were identified; 64% received ipilimumab monotherapy for a median duration of 9 weeks (range, 1-138). Sixty-four lesions in 44 patients were included in the study. Of these, nine lesions in eight patients were determined to be pseudoprogression and seven lesions were previously irradiated. Forty-four progression lesions and eight pseudoprogression lesions were hemorrhagic. Median lesion volume for pseudoprogression and progression were not significantly different, at 2.3 cm³ and 3.2 cm³, respectively (p = 0.82). The rVp⁹⁰ was smaller in pseudoprogression versus progression, at 2.2 and 5.3, respectively (p = 0.02), and remained significant after false discovery rate adjustment (p = 0.04).

CONCLUSIONS

Pseudoprogression exhibited significantly lower rVp⁹⁰ on DCE-MRI compared with progression. This knowledge can be useful for managing growing lesions in patients with melanoma brain metastases who are receiving immunotherapy.

NIMG-72. PROGNOSTIC VALUE OF [18F]-FDG POSITRON EMISSION TOMOGRAPHY IN PATIENTS WITH RECURRENT GLIOBLASTOMA RECEIVING BEVACIZUMAB

BACKGROUND

Bevacizumab is used extensively for the treatment of recurrent glioblastoma, and its modification of contrast-enhanced MRI creates a need for alternate prognostic read-outs. We sought to determine the prognostic value of [18F]-FDG (FDG) PET in glioblastoma patients performed during treatment with bevacizumab.

METHODS

We performed an institutional review board approved retrospective study on patients who underwent FDG PET within 4 weeks of a dose of bevacizumab for recurrent glioblastoma. Volumes of interest were placed over one reference lesion as defined by MRI. Maximum standardized uptake value (SUVmax) and peak standardized uptake value (SUVpeak) in this volume of interest were measured on PET, and metabolic tumor volume (MTV), total lesion glycolysis (TLG) and lesion-to-normal contralateral white matter ratios (SUVmax/cWM) were calculated. In addition, tumors were divided into 2 groups based on qualitative uptake pattern: (i) FDG non-avid and (ii) FDG avid. Statistical impact of PET parameters on overall survival (OS) was assessed, as was histopathological correlate of PET findings for patients with pathology available within 3 months of PET.

RESULTS

31 patients were included. Qualitative uptake pattern was significantly associated with OS (p = 0.005), with a median OS of 9.7 months in FDG non-avid patients versus 4.5 months in FDG avid patients. In univariate analysis, SUVmax, SUVpeak and T/N ratio were also significantly associated with OS (p < 0.001). Dichotomizing our sample using a SUVmax cut-off of 15.3 was also predictive of OS (adjusted p = 0.05). Pathology was available for 7 patients (22.6%) and confirmed PET findings.

CONCLUSION

FDG PET is a promising imaging biomarker to predict overall survival in recurrent glioblastoma patients on chronic antiangiogenic therapy, offering a tool for guiding assessment of treatment response in this patient population.

BRAF Inhibition in BRAFV600-Mutant Gliomas: Results From the VE-BASKET Study

Purpose

BRAF^V600 mutations are frequently found in several glioma subtypes, including pleomorphic xanthoastrocytoma (PXA) and ganglioglioma and much less commonly in glioblastoma. We sought to determine the activity of vemurafenib, a selective inhibitor of BRAF^V600, in patients with gliomas that harbor this mutation.

Patients and Methods

The VE-BASKET study was an open-label, nonrandomized, multicohort study for BRAF^V600-mutant nonmelanoma cancers. Patients with BRAF^V600-mutant glioma received vemurafenib 960 mg twice per day continuously until disease progression, withdrawal, or intolerable adverse effects. Key end points included confirmed objective response rate by RECIST version 1.1, progression-free survival, overall survival, and safety.

Results

Twenty-four patients (median age, 32 years; 18 female and six male patients) with glioma, including malignant diffuse glioma (n = 11; six glioblastoma and five anaplastic astrocytoma), PXA (n = 7), anaplastic ganglioglioma (n = 3), pilocytic astrocytoma (n = 2), and high-grade glioma, not otherwise specified (n = 1), were treated. Confirmed objective response rate was 25% (95% CI, 10% to 47%) and median progression-free survival was 5.5 months (95% CI, 3.7 to 9.6 months). In malignant diffuse glioma, best response included one partial response and five patients with stable disease, two of whom had disease stabilization that lasted more than 1 year. In PXA, best response included one complete response, two partial responses, and three patients with stable disease. Additional partial responses were observed in patients with pilocytic astrocytoma and anaplastic ganglioglioma (one each). The safety profile of vemurafenib was generally consistent with that of previously published studies.

Conclusion

Vemurafenib demonstrated evidence of durable antitumor activity in some patients with BRAF^V600-mutant gliomas, although efficacy seemed to vary qualitatively by histologic subtype. Additional study is needed to determine the optimal use of vemurafenib in patients with primary brain tumors and to identify the mechanisms driving differential responses across histologic subsets.

Rapid infusion rituximab is well tolerated in patients with primary CNS lymphoma

Aim:

To establish the safety and feasibility of rapidly infusing rituximab over 90 min in patients with primary CNS lymphoma (PCNSL).

Patients & methods:

We retrospectively reviewed all patients with PCNSL who received rapid rituximab infusions (RRI) from January 2016 to January 2017. Primary end point was incidence of infusion reactions.

Results & conclusion:

11 patients received a total of 44 RRIs. Rituximab was dosed at 500 or 750 mg/m². Premedication included acetaminophen and diphenhydramine. No infusion reactions occurred during any RRI. Two infusions were administered with steroids for neurologic symptoms at baseline (4.5%). Rapid administration of rituximab was safe and feasible for patients with PCNSL and at the higher doses received.

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.

Multicenter phase II study of temozolomide and myeloablative chemotherapy with autologous stem cell transplant for newly diagnosed anaplastic oligodendroglioma

Background

Anaplastic oligodendroglioma (AO) and anaplastic oligoastrocytoma (AOA) are chemotherapy-sensitive tumors with prolonged survival after radiochemotherapy. We report a prospective trial using induction temozolomide (TMZ) followed by myeloablative high-dose chemotherapy (HDC) with autologous stem-cell transplant (ASCT) as a potential strategy to defer radiotherapy.

Methods

Patients with AO/AOA received 6 cycles of TMZ (200 mg/m2 × 5/28 day). Responding patients were eligible for HDC (thiotepa 250 mg/m2/day × 3 days, then busulfan 3.2 mg/kg/day × 3 days), followed by ASCT. Genomic characterization was performed using next-generation sequencing.

Results

Forty-one patients were enrolled; 85% had 1p/19q codeleted tumors. After induction, 26 patients were eligible for HDC-ASCT and 21 agreed to proceed. There were no unexpected adverse events or toxic deaths. After median follow-up of 66 months, 2-year progression-free survival (PFS) for transplanted patients was 86%, 5-year PFS 60%, and no patient has died. Among all 1p/19q codeleted patients (N = 33), 5-year PFS was 50% and 5-year overall survival (OS) 93%, with median time to radiotherapy not reached. Next-generation sequencing disclosed typical oligodendroglioma-related mutations, including IDH1, TERT, CIC, and FUBP1 mutations in 1p/19q codeleted patients, and glioblastoma-like signatures in 1p/19q intact patients. Aside from IDH1, potentially oncogenic/actionable mutations were variable, depicting wide molecular heterogeneity within oligodendroglial tumors.

Conclusions

TMZ followed by HDC-ASCT can be safely administered to patients with newly diagnosed 1p/19q codeleted AO. This strategy was associated with promising PFS and OS, suggesting that a chemotherapy-based approach may delay the need for radiotherapy and radiation-related toxicities. Raw data for further genomic and meta-analyses are publicly available at http://cbioportal.org/study?id=odg_msk_2017, accessed 6 January 2017.

Clinicaltrials.gov registry

NCT00588523.

Phase I Study of MEDI3617, a Selective Angiopoietin-2 Inhibitor Alone and Combined with Carboplatin/Paclitaxel, Paclitaxel, or Bevacizumab for Advanced Solid Tumors

Purpose: This first-in-human study aimed to determine the MTD and safety of MEDI3617, a selective anti-angiopoietin-2 (Ang2) mAb, alone and combined with bevacizumab or cytotoxic chemotherapy.Patients and Methods: This phase I/Ib, multicenter, open-label, dose-escalation and dose-expansion study evaluated patients with advanced solid tumors. Patients received intravenous MEDI3617 as monotherapy [5-1,500 mg every 3 weeks (Q3W)] or with bevacizumab every 2 weeks (Q2W) or Q3W, weekly paclitaxel, or carboplatin plus paclitaxel Q3W. Dose expansions included a monotherapy cohort in platinum-resistant ovarian cancer and a bevacizumab combination cohort in bevacizumab-refractory malignant glioma. Safety/tolerability, pharmacokinetics, pharmacodynamics, and clinical activity were assessed.Results: We enrolled 116 patients. No formal MTD was identified (monotherapy or combination therapy). MEDI3617 demonstrated linear pharmacokinetics and maximal accumulation of peripheral Ang2 binding at doses above 300 mg Q3W. MEDI3617 monotherapy safety profile was acceptable, except in advanced ovarian cancer [prolonged grade 3 edema-associated adverse events (AE) occurred]. Otherwise, MEDI3617 combined with chemotherapy or bevacizumab was well tolerated. The AE profiles of MEDI3617 and bevacizumab were largely non-overlapping. Overall response rates in ovarian cancer and glioma monotherapy dose-expansion arms were 6% and 0%, respectively.Conclusions: Recommended MEDI3617 monotherapy dosage is 1,500 mg Q3W or 1,000 mg Q2W, except in ovarian cancer. Although peripheral edema has occurred with other Ang2 inhibitors, the severity and duration seen here in ovarian cancer potentially identifies a new, clinically significant safety signal for this class of agents. On the basis of limited clinical activity, MEDI3617 development was discontinued. Clin Cancer Res; 24(12); 2749-57. ©2018 AACR.

OncoKB: A Precision Oncology Knowledge Base

PURPOSE

With prospective clinical sequencing of tumors emerging as a mainstay in cancer care, there is an urgent need for a clinical support tool that distills the clinical implications associated with specific mutation events into a standardized and easily interpretable format. To this end, we developed OncoKB, an expert-guided precision oncology knowledge base.

METHODS

OncoKB annotates the biological and oncogenic effect and the prognostic and predictive significance of somatic molecular alterations. Potential treatment implications are stratified by the level of evidence that a specific molecular alteration is predictive of drug response based on US Food and Drug Administration (FDA) labeling, National Comprehensive Cancer Network (NCCN) guidelines, disease-focused expert group recommendations and the scientific literature.

RESULTS

To date, over 3000 unique mutations, fusions, and copy number alterations in 418 cancer-associated genes have been annotated. To test the utility of OncoKB, we annotated all genomic events in 5983 primary tumor samples in 19 cancer types. Forty-one percent of samples harbored at least one potentially actionable alteration, of which 7.5% were predictive of clinical benefit from a standard treatment. OncoKB annotations are available through a public web resource (http://oncokb.org/) and are also incorporated into the cBioPortal for Cancer Genomics to facilitate the interpretation of genomic alterations by physicians and researchers.

CONCLUSION

OncoKB, a comprehensive and curated precision oncology knowledge base, offers oncologists detailed, evidence-based information about individual somatic mutations and structural alterations present in patient tumors with the goal of supporting optimal treatment decisions.

Multicenter, Phase 1, Dose Escalation Study of Hypofractionated Stereotactic Radiation Therapy With Bevacizumab for Recurrent Glioblastoma and Anaplastic Astrocytoma

PURPOSE

To establish the maximum tolerated dose of a 3-fraction hypofractionated stereotactic reirradiation schedule when delivered with concomitant bevacizumab to treat recurrent high-grade gliomas.

METHODS AND MATERIALS

Patients with recurrent high-grade glioma with Karnofsky performance status ≥60, history of standard fractionated initial radiation, tumor volume at recurrence ≤40 cm³, and absence of brainstem or corpus callosum involvement were eligible. A standard 3+3 phase 1 dose escalation trial design was utilized, with dose-limiting toxicities defined as any grade 3 to 5 toxicities possibly, probably, or definitely related to radiation. Bevacizumab was given at a dose of 10 mg/kg every 2 weeks. Hypofractionated stereotactic reirradiation was initiated after 2 bevacizumab doses, delivered in 3 fractions every other day, starting at 9 Gy per fraction.

RESULTS

A total of 3 patients were enrolled at the 9 Gy × 3 dose level cohort, 5 in the 10 Gy × 3 cohort, and 7 in the 11 Gy × 3 cohort. One dose-limiting toxicity of grade 3 fatigue and cognitive deterioration possibly related to hypofractionated stereotactic reirradiation was observed in the 11 Gy × 3 cohort, and this dose was declared the maximum tolerated dose in combination with bevacizumab. Although no symptomatic radionecrosis was observed, substantial treatment-related effects and necrosis were observed in resected specimens. The intent-to-treat median overall survival was 13 months.

CONCLUSIONS

Reirradiation using a 3-fraction schedule with bevacizumab support is feasible and reasonably well tolerated. Dose-escalation was possible up to 11 Gy × 3, which achieves a near doubling in the delivered biological equivalent dose to normal brain, in comparison with our previous 6 Gy × 5 schedule. Promising overall survival warrants further investigation.

Abstract P6-10-05: A pilot study of radiation (RT) and CTLA4-mediated checkpoint blockade with tremelimumab for the treatment of breast cancer brain metastases (BCBM)

This abstract was withdrawn by the authors.

Abstract IA20: Phase II study to evaluate the clinical efficacy and safety of MEDI4736 (durvalumab) in patients with glioblastoma (GBM): Results for cohort B (durvalumab monotherapy), bevacizumab-naïve patients with recurrent GBM

Background: Outcome for patients with glioblastoma (GBM), the most common primary malignancy of the central nervous system, remains poor. Inhibition of PD-1 signaling has been shown to improve survival in an orthotopic, syngeneic murine GBM model. PD-L1 is expressed by GBM tumors, and its level of expression has been shown to correlate with patient outcome. Durvalumab (DUR) is a human IgG1 monoclonal antibody against PD-L1. Blockade of PD-1/PD-L1 has shown benefit among solid tumors; data implicate PD-1/PD-L1 signaling as a significant contributor to immunosuppression in glioblastoma (GBM). Bevacizumab (BEV) is an approved angiogenesis inhibitor for recurrent GBM; angiogenesis inhibition may promote antitumor benefit of immunotherapies. Methods: This ongoing phase II open-label study (NCT02336165) evaluates the safety and efficacy of DUR (10 mg/kg every 2 weeks) in 5 GBM cohorts with and without BEV. This report presents the safety and efficacy for Cohort B (BEV-naïve recurrent GBM; DUR monotherapy). The primary efficacy endpoint for Cohort B is progression-free survival at 6 months (PFS-6), based on modified RANO criteria by investigator assessment; secondary endpoints include safety/tolerability. A PFS-6 of 10% is the comparative historical benchmark (pre-BEV), based on published meta-analyses. The null hypothesis (PFS-6 ≤ 10%) was tested in the Intent-to-Treat (ITT) population against the alternative hypothesis (PFS-6 &gt; 10%) at α = 0.05, using 90% confidence interval (CI). The null hypothesis was rejected if the lower bound of the CI was &gt; 10%. ITT includes patients receiving any dose of DUR and having at least baseline and 1 post-baseline tumor assessment. Results: The first patient was dosed on 05Mar2015, and the data cutoff was 05Feb2016. Cohort B completed enrollment of 31 patients (male: 83.9%; mean age: 54.0 [24-77] years; baseline ECOG Performance Status (PS) 0: 51.6%, PS 1: 48.4%; baseline measurable lesions: 77.4%). Incidences of treatment-related adverse events (TRAEs) by maximum CTCAE grade (Gr) were Gr1: 35.5%; Gr2: 41.9%; Gr3: 9.7%; and Gr4/5: 0%. Most common TRAEs (≥3 (9.7%) patients) were fatigue, headache, hemiparesis, increased AST, and decreased platelets, WBCs and lymphocytes. Thirty patients were evaluable for efficacy (PFS), and 6 were progression free at 6 months. Kaplan-Meier estimate for PFS-6 was 20%. Conclusions: DUR appears to be well tolerated and shows activity in BEV-naïve recurrent GBM, although the primary PFS-6 endpoint was not met. Further studies are warranted.

Citation Format: David A. Reardon, Thomas Kaley, Jorg Dietrich, Michael Lim, Gavin P. Dunn, Hui K. Gan, Timothy Cloughesy, Jennifer L. Clarke, Andrew Park, Mary Macri, Aileen Ryan, Toni Ricciardi, Vijay Reddy, Ralph Venhaus. Phase II study to evaluate the clinical efficacy and safety of MEDI4736 (durvalumab) in patients with glioblastoma (GBM): Results for cohort B (durvalumab monotherapy), bevacizumab-naïve patients with recurrent GBM [abstract]. In: Proceedings of the Second CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; 2016 Sept 25-28; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(11 Suppl):Abstract nr IA20.

Central Nervous System Cancers, Version 1.2015

The NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Central Nervous System (CNS) Cancers provide interdisciplinary recommendations for managing adult CNS cancers. Primary and metastatic brain tumors are a heterogeneous group of neoplasms with varied outcomes and management strategies. These NCCN Guidelines Insights summarize the NCCN CNS Cancers Panel's discussion and highlight notable changes in the 2015 update. This article outlines the data and provides insight into panel decisions regarding adjuvant radiation and chemotherapy treatment options for high-risk newly diagnosed low-grade gliomas and glioblastomas. Additionally, it describes the panel's assessment of new data and the ongoing debate regarding the use of alternating electric field therapy for high-grade gliomas.

Molecular and Clinical Effects of Notch Inhibition in Glioma Patients: A Phase 0/I Trial

PURPOSE

High-grade gliomas are associated with a dismal prognosis. Notch inhibition via the gamma-secretase inhibitor RO4929097 has emerged as a potential therapeutic option based on modulation of the cancer-initiating cell (CIS) population and a presumed antiangiogenic role.

EXPERIMENTAL DESIGN

In this phase 0/I trial, 21 patients with newly diagnosed glioblastoma or anaplastic astrocytoma received RO4929097 combined with temozolomide and radiotherapy. In addition to establishing the MTD, the study design enabled exploratory studies evaluating tumor and brain drug penetration and neuroimaging parameters. We also determined functional effects on the Notch pathway and targeting of CISs through analysis of tumor tissue sampled from areas with and without blood-brain barrier disruption. Finally, recurrent tumors were also sampled and assessed for Notch pathway responses while on treatment.

RESULTS

Treatment was well tolerated and no dose-limiting toxicities were observed. IHC of treated tumors showed a significant decrease in proliferation and in the expression of the Notch intracellular domain (NICD) by tumor cells and blood vessels. Patient-specific organotypic tumor explants cultures revealed a specific decrease in the CD133⁺ CIS population upon treatment. Perfusion MRI demonstrated a significant decrease in relative plasma volume after drug exposure. Gene expression data in recurrent tumors suggested low Notch signaling activity, the upregulation of key mesenchymal genes, and an increase in VEGF-dependent angiogenic factors.

CONCLUSIONS

The addition of RO4929097 to temozolomide and radiotherapy was well tolerated; the drug has a variable blood-brain barrier penetration. Evidence of target modulation was observed, but recurrence occurred, associated with alterations in angiogenesis signaling pathways. Clin Cancer Res; 22(19); 4786-96. ©2016 AACR.