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Background: Multidimensional genotyping of formalin-fixed paraffin-embedded (FFPE) samples has the potential to improve diagnostics and clinical trials for brain tumors, but prospective use in the clinical setting is not yet routine. We report our experience with implementing a multiplexed copy number and mutation-testing program in a diagnostic laboratory certified by the Clinical Laboratory Improvement Amendments., Methods: We collected and analyzed clinical testing results from whole-genome array comparative genomic hybridization (OncoCopy) of 420 brain tumors, including 148 glioblastomas. Mass spectrometry-based mutation genotyping (OncoMap, 471 mutations) was performed on 86 glioblastomas., Results: OncoCopy was successful in 99% of samples for which sufficient DNA was obtained (n = 415). All clinically relevant loci for glioblastomas were detected, including amplifications (EGFR, PDGFRA, MET) and deletions (EGFRvIII, PTEN, 1p/19q). Glioblastoma patients ≤40 years old had distinct profiles compared with patients >40 years. OncoMap testing reliably identified mutations in IDH1, TP53, and PTEN. Seventy-seven glioblastoma patients enrolled on trials, of whom 51% participated in targeted therapeutic trials where multiplex data informed eligibility or outcomes. Data integration identified patients with complete tumor suppressor inactivation, albeit rarely (5% of patients) due to lack of whole-gene coverage in OncoMap., Conclusions: Combined use of multiplexed copy number and mutation detection from FFPE samples in the clinical setting can efficiently replace singleton tests for clinical diagnosis and prognosis in most settings. Our results support incorporation of these assays into clinical trials as integral biomarkers and their potential to impact interpretation of results. Limited tumor suppressor variant capture by targeted genotyping highlights the need for whole-gene sequencing in glioblastoma., (© The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Neuro-Oncology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Bevacizumab is frequently used to treat patients with recurrent high-grade glioma (HGG), but responses are generally not durable. Panobinostat is a histone deacetylase inhibitor with anti-neoplastic and anti-angiogenic effects and may work synergistically with VEGF inhibitors. We performed a phase I study to evaluate the safety and tolerability of the combination of orally administered panobinostat with bevacizumab in patients with recurrent HGG. Patients with recurrent HGG were treated on a 3 + 3 trial design. Patients received bevacizumab 10 mg/kg every other week in combination with oral panobinostat. The starting dose of panobinostat was 20 mg three times per week, weekly (cohort 1). Due to concerns for thrombocytopenia with the weekly dosing regimen, the protocol was amended to examine an every other week regimen. Cohort 2 received panobinostat 20 mg three times per week, every other week, and cohort 3 received 30 mg three times per week, every other week. Dose-limiting toxicity during the first 30 days was used to determine the maximum-tolerated dose. Twelve patients (median age 50, median KPS 90) with recurrent HGG were enrolled. One dose-limiting toxicity (DLT) (Grade 3 thrombocytopenia) was observed in cohort 1. No DLTs were observed in cohorts 2 and 3. The following grade 3 toxicities were seen in one patient each: thrombocytopenia, hypophosphatemia, esophageal hemorrhage, and deep venous thrombosis. There were no grade 4 or 5 toxicities. There were three patients with partial responses and seven with stable disease. The recommended doses for further study are oral panobinostat 30 mg three times per week, every other week, in combination with bevacizumab 10 mg/kg every other week. A phase II clinical trial in recurrent HGG is underway.

Venous thromboembolic events (VTE) are common in glioma patients and are typically treated with anticoagulant medications. The anti-angiogenic agent bevacizumab (BVZ) increases the risks of both VTE and hemorrhagic complications. Little is known about the hemorrhagic risk of anticoagulation in glioma patients receiving BVZ. We reviewed medical records from 282 BVZ-treated patients at our center and identified 64 who received concurrent anticoagulant therapy. The risk and severity of hemorrhagic complications were assessed. Fisher's exact test was used to compare the risk of hemorrhage between subjects who received and did not receive anticoagulants. Forty-seven patients (73%) had glioblastoma, 15 (23%) anaplastic glioma, and 2 (3%) other tumors. Thirteen (20%) and 51 (80%) patients received warfarin and low-molecular-weight heparin, respectively. The indication for anticoagulation was deep venous thrombosis in 37 patients (58%), pulmonary embolism in 22 (34%), and both in 5 (8%). Thirteen patients (20%) experienced hemorrhage, of which four hemorrhages (6%) were serious (grade ≥ 3): one patient had grade 5 intracerebral hemorrhage (ICH), one grade 4 ICH, one grade 3 epistaxis, and one grade 3 gastrointestinal hemorrhage. ICH was seen in seven patients (11%), of which five (8%) were grade 1. Among 218 patients who did not receive anticoagulants, there were two (1%) serious hemorrhages (both grade 4 ICH). Both the serious hemorrhage rate and overall ICH rate were higher in patients who received anticoagulants (P = 0.03 and 0.02, respectively). Anticoagulant use during BVZ therapy may increase the risk of hemorrhage in glioma patients, although it is generally well tolerated.

There is no effective treatment for recurrent glioblastoma (GBM) after bevacizumab failure. Putative mechanisms of resistance to bevacizumab include increased pericyte coverage, mediated partly by platelet-derived growth factor receptor (PDGFR) signaling, and an infiltrative tumor growth pattern potentially dependent on SRC. We explored the efficacy of dasatinib, a SRC, BCR-ABL, c-KIT, EPHA2, and PDGFRβ inhibitor, in patients with recurrent GBM after bevacizumab failure. Adult patients with histologically confirmed GBM who failed bevacizumab therapy were treated with dasatinib 70-100 mg twice daily in combination with bevacizumab (n = 14), until tumor progression or unacceptable toxicity. Fourteen patients were treated. Median age was 55 years (range 32-66) and median KPS was 80 (range 50-90). All patients (100%) had glioblastomas. The median number of prior regimens was 4 (range from 2 to 6). Of the thirteen evaluable patients, none had a complete or partial response. Only one patient had stable disease after an 8 week interval. Median progression-free survival (PFS) was 28 days (95% confidence interval [CI] 26-35 days). Six month progression-free survival (PFS6) was 0%. Median overall survival (OS) was 78 days (95% CI 41-137 days). Treatment was moderately well-tolerated, although one patient sustained a grade 4 intracerebral hemorrhage. Dasatinib in conjunction with bevacizumab does not appear to have activity in patients with recurrent, heavily pretreated GBM.

Purpose: Increasing evidence has suggested that angiogenesis inhibition might potentiate the effects of radiotherapy and chemotherapy in patients with glioblastoma (GBM). In addition, epidermal growth factor receptor inhibition might be of therapeutic benefit, because the epidermal growth factor receptor is upregulated in GBM and contributes to radiation resistance. We conducted a Phase I study of vandetanib, an inhibitor of vascular endothelial growth factor receptor 2 and epidermal growth factor receptor, in patients with newly diagnosed GBM combined with RT and temozolomide (TMZ)., Methods and Materials: A total of 13 GBM patients were treated with vandetanib, radiotherapy, and concurrent and adjuvant TMZ, using a standard "3 + 3" dose escalation. The maximal tolerated dose was defined as the dose with <1 of 6 dose-limiting toxicities during the first 12 weeks of therapy. The eligible patients were adults with newly diagnosed GBM, Karnofsky performance status of >or=60, normal organ function, who were not taking enzyme-inducing antiepileptic drugs., Results: Of the 13 patients, 6 were treated with vandetanib at a dose of 200mg daily. Of the 6 patients, 3 developed dose-limiting toxicities within the first 12 weeks, including gastrointestinal hemorrhage and thrombocytopenia in 1 patient, neutropenia in 1 patient, and diverticulitis with gastrointestinal perforation in 1 patient. The other 7 patients were treated with 100 mg daily, with no dose-limiting toxicities observed, establishing this dose as the maximal tolerated dose combined with TMZ and RT., Conclusion: Vandetanib can be safely combined with RT and TMZ in GBM patients. A Phase II study in which patients are randomized to vandetanib 100 mg daily with RT and TMZ or RT and TMZ alone is underway., (Copyright (c) 2010 Elsevier Inc. All rights reserved.)