BackgroundThis study evaluated the safety and immune responses to an autologous dendritic cell vaccine pulsed with class I peptides from tumor-associated antigens (TAA) expressed on gliomas and overexpressed in their cancer stem cell population (ICT-107).MethodsTAA epitopes included HER2, TRP-2, gp100, MAGE-1, IL13Rα2, and AIM-2. HLA-A1- and/or HLA-A2-positive patients with glioblastoma (GBM) were eligible. Mononuclear cells from leukapheresis were differentiated into dendritic cells, pulsed with TAA peptides, and administered intradermally three times at two-week intervals.ResultsTwenty-one patients were enrolled with 17 newly diagnosed (ND-GBM) and three recurrent GBM patients and one brainstem glioma. Immune response data on 15 newly diagnosed patients showed 33 % responders. TAA expression by qRT-PCR from fresh-frozen tumor samples showed all patient tumors expressed at least three TAA, with 75 % expressing all six. Correlations of increased PFS and OS with quantitative expression of MAGE1 and AIM-2 were observed, and a trend for longer survival was observed with gp100 and HER2 antigens. Target antigens gp100, HER1, and IL13Rα2 were downregulated in recurrent tumors from 4 HLA-A2+ patients. A decrease in or absence of CD133 expression was seen in five patients who underwent a second resection. At a median follow-up of 40.1 months, six of 16 ND-GBM patients showed no evidence of tumor recurrence. Median PFS in newly diagnosed patients was 16.9 months, and median OS was 38.4 months.ConclusionsExpression of four ICT-107 targeted antigens in the pre-vaccine tumors correlated with prolonged overall survival and PFS in ND-GBM patients. The goal of targeting tumor antigens highly expressed on glioblastoma cancer stem cells is supported by the observation of decreased or absent CD133 expression in the recurrent areas of gadolinium-enhanced tumors.

Human interleukin-12 (hIL-12) is a cytokine with anticancer activity, but its systemic application is limited by toxic inflammatory responses. We assessed the safety and biological effects of an hIL-12 gene, transcriptionally regulated by an oral activator. A multicenter phase 1 dose-escalation trial (NCT02026271) treated 31 patients undergoing resection of recurrent high-grade glioma. Resection cavity walls were injected (day 0) with a fixed dose of the hIL-12 vector (Ad–RTS–hIL-12). The oral activator for hIL-12, veledimex (VDX), was administered preoperatively (assaying blood-brain barrier penetration) and postoperatively (measuring hIL-12 transcriptional regulation). Cohorts received 10 to 40 mg of VDX before and after Ad–RTS–hIL-12. Dose-related increases in VDX, IL-12, and interferon-γ (IFN-γ) were observed in peripheral blood, with about 40% VDX tumor penetration. Frequency and severity of adverse events, including cytokine release syndrome, correlated with VDX dose, reversing promptly upon discontinuation. VDX (20 mg) had superior drug compliance and 12.7 months median overall survival (mOS) at mean follow-up of 13.1 months. Concurrent corticosteroids negatively affected survival: In patients cumulatively receiving >20 mg versus ≤20 mg of dexamethasone (days 0 to 14), mOS was 6.4 and 16.7 months, respectively, in all patients and 6.4 and 17.8 months, respectively, in the 20-mg VDX cohort. Re-resection in five of five patients with suspected recurrence after Ad–RTS–hIL-12 revealed mostly pseudoprogression with increased tumor-infiltrating lymphocytes producing IFN-γ and programmed cell death protein 1 (PD-1). These inflammatory infiltrates support an immunological antitumor effect of hIL-12. This phase 1 trial showed acceptable tolerability of regulated hIL-12 with encouraging preliminary results.

Recurrent glioblastoma multiforme (GBM) is a highly aggressive cancer with poor prognosis, and an overall survival of 6 to 7 months with optimal therapies. The NovoTTF-100A™ System is a novel antimitotic cancer therapy recently approved for the treatment of recurrent GBM, based on phase III (EF-11) trial results. The Patient Registry Dataset (PRiDe) is a post-marketing registry of all recurrent GBM patients who received NovoTTF Therapy in a real-world, clinical practice setting in the United States between 2011 and 2013. Data were collected from all adult patients with recurrent GBM who began commercial NovoTTF Therapy in the United States between October 2011 and November 2013. All patients provided written consent before treatment was started. Overall survival (OS) curves were constructed for PRiDe using the Kaplan-Meier method. Median OS in PRiDe was compared for patients stratified by average daily compliance (≥75% v<75% per day) and other prognostic variables. Adverse events were also evaluated. Data from 457 recurrent GBM patients who received NovoTTF Therapy in 91 US cancer centers were analyzed. More patients in PRiDe than the EF-11 trial received NovoTTF Therapy for first recurrence (33% v 9%) and had received prior bevacizumab therapy (55.1% v 19%). Median OS was significantly longer with NovoTTF Therapy in clinical practice (PRiDe data set) than in the EF-11 trial (9.6 v 6.6 months; HR, 0.66; 95% CI, 0.05 to 0.86, P = .0003). One- and 2-year OS rates were more than double for NovoTTF Therapy patients in PRiDe than in the EF-11 trial (1-year: 44% v 20%; 2-year: 30% v 9%). First and second versus third and subsequent recurrences, high Karnofsky performance status (KPS), and no prior bevacizumab use were favorable prognostic factors. No unexpected adverse events were detected in PRiDe. As in the EF-11 trial, the most frequent adverse events were mild to moderate skin reactions associated with application of the NovoTTF Therapy transducer arrays. Results from PRiDe, together with those previously reported in the EF-11 trial, indicate that NovoTTF Therapy offers clinical benefit to patients with recurrent GBM. NovoTTF Therapy has high patient tolerability and favorable safety profile in the real-world, clinical practice setting.

Atypical and anaplastic (WHO Grades II and III) meningiomas are aggressive tumors, and patients often progress despite surgery and radiation. There is no known effective chemotherapeutic option for these patients. Meningiomas have a high expression of vascular endothelial growth factor receptor (VEGFR). We sought to retrospectively study the activity of bevacizumab, which is an anti-angiogenic agent targeting the VEGF pathway in these tumors. This is a retrospective review of WHO Grade II and III meningiomas treated at four institutions, selecting only those patients who received bevacizumab. We analyzed radiographic response according to standard RANO criteria, progression-free survival (PFS) and overall survival from the initiation of bevacizumab therapy using Kaplan-Meier statistics. We identified 15 patients across four institutions who carried a diagnosis of atypical or anaplastic meningioma and were treated with bevacizumab. Best radiographic response was stable disease. MR perfusion studies showed decreased tumor blood volume in one patient. Three patients developed non-fatal intratumoral hemorrhage. Median PFS was 26 weeks (95 % CI, 10-29 weeks). Six month PFS rate was 43.8 % (95 % CI, 15.7-69.1 %). Bevacizumab was well-tolerated in our patients, and may be considered in patients who have exhausted radiation and surgical options. Prospective studies are required to define the safety and efficacy of bevacizumab in atypical and anaplastic meningiomas.

There is an unmet need for the treatment of glioblastoma multiforme (GBM). The extracellular matrix, including laminins, in the tumor microenvironment is important for tumor invasion and progression. In a panel of 226 patient brain glioma samples, we found a clinical correlation between the expression of tumor vascular laminin-411 (a4b1g1) with higher tumor grade and with expression of cancer stem cell (CSC) markers, including Notch pathway members, CD133, Nestin, and c-Myc. Laminin-411 overexpression also correlated with higher recurrence rate and shorter survival of GBM patients. We also showed that depletion of laminin-411 a4 and b1 chains with CRISPR/Cas9 in human GBM cells led to reduced growth of resultant intracranial tumors in mice and significantly increased survival of host animals compared with mice with untreated cells. Inhibition of laminin-411 suppressed Notch pathway in normal and malignant human brain cell types. A nanobioconjugate potentially suitable for clinical use and capable of crossing blood-brain barrier was designed to block laminin-411 expression. Nanobioconjugate treatment of mice carrying intracranial GBM significantly increased animal survival and inhibited multiple CSC markers, including the Notch axis. This study describes an efficient strategy for GBM treatment via targeting a critical component of the tumor microenvironment largely independent of heterogeneous genetic mutations in glioblastoma. Significance: Laminin-411 expression in the glioma microenvironment correlates with Notch and other cancer stem cell markers and can be targeted by a novel, clinically translatable nanobioconjugate to inhibit glioma growth.