Glioblastoma, the most aggressive primary brain tumor in humans, exhibits a large degree of molecular heterogeneity. Understanding the molecular pathology of a tumor and its linkage to behavior is an important foundation for developing and evaluating approaches to clinical management. Here we integrate array-comparative genomic hybridization and array-based gene expression profiles to identify relationships between DNA copy number aberrations, gene expression alterations, and survival in 34 patients with glioblastoma. Unsupervised clustering on either profile resulted in similar groups of patients, and groups defined by either method were associated with survival. The high concordance between these separate molecular classifications suggested a strong association between alterations on the DNA and RNA levels. We therefore investigated relationships between DNA copy number and gene expression changes. Loss of chromosome 10, a predominant genetic change, was associated not only with changes in the expression of genes located on chromosome 10 but also with genome-wide differences in gene expression. We found that CHI3L1/YKL-40 was significantly associated with both chromosome 10 copy number loss and poorer survival. Immortalized human astrocytes stably transfected with CHI3L1/YKL-40 exhibited changes in gene expression similar to patterns observed in human tumors and conferred radioresistance and increased invasion in vitro. Taken together, the results indicate that integrating DNA and mRNA-based tumor profiles offers the potential for a clinically relevant classification more robust than either method alone and provides a basis for identifying genes important in glioma pathogenesis.

Purpose: To evaluate the results of the randomized, double-blind, placebo-controlled phase II clinical trial of ICT-107 in patients with newly diagnosed glioblastoma. Patients and Methods: We conducted a double-blinded randomized phase II trial of ICT-107 in newly diagnosed patients with glioblastoma (GBM) and tested efficacy, safety, quality of life (QoL), and immune response. HLA-A1⁺ and/or -A2⁺–resected patients with residual tumor ≤1 cm³ received radiotherapy and concurrent temozolomide. Following completion of radiotherapy, 124 patients, randomized 2:1, received ICT-107 [autologous dendritic cells (DC) pulsed with six synthetic peptide epitopes targeting GBM tumor/stem cell–associated antigens MAGE-1, HER-2, AIM-2, TRP-2, gp100, and IL13Rα2] or matching control (unpulsed DC). Patients received induction ICT-107 or control weekly × 4 followed by 12 months of adjuvant temozolomide. Maintenance vaccinations occurred at 1, 3, and 6 months and every 6 months thereafter. Results: ICT-107 was well tolerated, with no difference in adverse events between the treatment and control groups. The primary endpoint, median overall survival (OS), favored ICT-107 by 2.0 months in the intent-to-treat (ITT) population but was not statistically significant. Progression-free survival (PFS) in the ITT population was significantly increased in the ICT-107 cohort by 2.2 months (P = 0.011). The frequency of HLA-A2 primary tumor antigen expression was higher than that for HLA-A1 patients, and HLA-A2 patients had higher immune response (via Elispot). HLA-A2 patients achieved a meaningful therapeutic benefit with ICT-107, in both the MGMT methylated and unmethylated prespecified subgroups, whereas only HLA-A1 methylated patients had an OS benefit. Conclusions: PFS was significantly improved in ICT-107–treated patients with maintenance of QoL. Patients in the HLA-A2 subgroup showed increased ICT-107 activity clinically and immunologically.

Purpose: Proton magnetic resonance spectroscopy (MRS) of the brain can detect 2-hydroxyglutarate (2HG), the oncometabolite produced in neoplasms harboring a mutation in the gene coding for isocitrate dehydrogenase ( IDH). We conducted a prospective longitudinal imaging study to determine whether quantitative assessment of 2HG by MRS could serve as a noninvasive clinical imaging biomarker for IDH-mutated gliomas. Patients and Methods: 2HG MRS was performed in 136 patients using point-resolved spectroscopy at 3 T in parallel with standard clinical magnetic resonance imaging and assessment. Data were analyzed in patient cohorts representing the major phases of the glioma clinical course and were further subgrouped by histology and treatment type to evaluate 2HG. Histologic correlations were performed. Results: Quantitative 2HG MRS was technically and biologically reproducible. 2HG concentration > 1 mM could be reliably detected with high confidence. During the period of indolent disease, 2HG concentration varied by less than ± 1 mM, and it increased sharply with tumor progression. 2HG concentration was positively correlated with tumor cellularity and significantly differed between high- and lower-grade gliomas. In response to cytotoxic therapy, 2HG concentration decreased rapidly in 1p/19q codeleted oligodendrogliomas and with a slower time course in astrocytomas and mixed gliomas. The magnitude and time course of the decrease in 2HG concentration and magnitude of the decrease in tumor volume did not differ between oligodendrogliomas treated with temozolomide or carmustine. Criteria for 2HG MRS were established to make a presumptive molecular diagnosis of an IDH mutation in gliomas technically unable to undergo a surgical procedure. Conclusion: 2HG concentration as measured by MRS was reproducible and reliably reflected the disease state. These data provide a basis for incorporating 2HG MRS into clinical management of IDH-mutated gliomas.

Significance: The prognosis and management of patients with glioma is vastly different depending on whether one detects tumor progression or treatment effects. Although the gold standard in the evaluation of treatment efficacy involves MRI, the currently available imaging methods often do not suffice to make the final decision. Our study demonstrated that amide proton transfer (APT) imaging, one subset of chemical exchange saturation transfer imaging, can detect molecular signals in glioma induced by short-term chemotherapy with temozolomide. These molecular events precede morphologic changes. The APT signal did not decrease in tumors resistant to chemotherapy. APT imaging may provide a useful prognostic biomarker of treatment response or tumor progression in glioma.

The FDA's approval of bevacizumab for recurrent glioblastoma on May 9, 2009, was based on the significant response rate and clinical benefits seen from randomized phase II studies. Large-scale phase III data are unavailable. In an effort to determine benchmark efficacy parameters for bevacizumab and analyze its dose–response effect, the authors performed a meta-analysis of 15 studies published from 2005 to 2009, involving 548 patients with a median age of 53 years (range, 5–74 years), that used bevacizumab to treat recurrent glioblastoma. Median overall survival was 9.3 months (95% CI, 7.9–10.6 months). The respective 6-month progression-free and 6-month overall survival rates were 45% (95% CI, 34%–57%) and 76% (95% CI, 69%–84%), respectively. Median time to tumor progression was 6.1 months (95% CI, 4.2–8.1 months). The response analysis yielded a 6% complete response (95% CI, 2%–9%), 49% partial response (95% CI, 37%–61%), and 29% stable disease (95% CI, 20%–38%). No difference was seen in bevacizumab dose–response benefit between 5 mg/kg and 10 to 15 mg/kg. The efficacy benchmarks from this meta-analysis did not differ from those of the recently published randomized phase II studies. The lack of a dose–response effect would require confirmation in a prospectively conducted clinical trial. The FDA's approval of bevacizumab for recurrent glioblastoma on May 9, 2009, was based on the significant response rate and clinical benefits seen from randomized phase II studies. Large-scale phase III data are unavailable. In an effort to determine benchmark efficacy parameters for bevacizumab and analyze its dose–response effect, the authors performed a meta-analysis of 15 studies published from 2005 to 2009, involving 548 patients with a median age of 53 years (range, 5–74 years), that used bevacizumab to treat recurrent glioblastoma. Median overall survival was 9.3 months (95% CI, 7.9–10.6 months). The respective 6-month progression-free and 6-month overall survival rates were 45% (95% CI, 34%–57%) and 76% (95% CI, 69%–84%), respectively. Median time to tumor progression was 6.1 months (95% CI, 4.2–8.1 months). The response analysis yielded a 6% complete response (95% CI, 2%–9%), 49% partial response (95% CI, 37%–61%), and 29% stable disease (95% CI, 20%–38%). No difference was seen in bevacizumab dose–response benefit between 5 mg/kg and 10 to 15 mg/kg. The efficacy benchmarks from this meta-analysis did not differ from those of the recently published randomized phase II studies. The lack of a dose–response effect would require confirmation in a prospectively conducted clinical trial.

Aberrant epidermal growth factor receptor (EGFR) signaling is widespread in cancer, making the EGFR an important target for therapy. EGFR gene amplification and mutation are common in glioblastoma (GBM), but EGFR inhibition has not been effective in treating this tumor. Here we propose that primary resistance to EGFR inhibition in glioma cells results from a rapid compensatory response to EGFR inhibition that mediates cell survival. We show that in glioma cells expressing either EGFR wild type or the mutant EGFRvIII, EGFR inhibition triggers a rapid adaptive response driven by increased tumor necrosis factor (TNF) secretion, which leads to activation in turn of c-Jun N-terminal kinase (JNK), the Axl receptor tyrosine kinase and extracellular signal–regulated kinases (ERK). Inhibition of this adaptive axis at multiple nodes rendered glioma cells with primary resistance sensitive to EGFR inhibition. Our findings provide a possible explanation for the failures of anti-EGFR therapy in GBM and suggest a new approach to the treatment of EGFR-expressing GBM using a combination of EGFR and TNF inhibition.