A replication-defective poliovirus was injected directly into recurrent glioblastoma tumors, and dexamethasone and bevacizumab were used to control edema. A total of 20% of the treated patients have ...survived beyond 3 years.
The majority of glioblastomas can be classified into molecular subgroups based on mutations in the TERT promoter (TERTp) and isocitrate dehydrogenase 1 or 2 (IDH). These molecular subgroups utilize ...distinct genetic mechanisms of telomere maintenance, either TERTp mutation leading to telomerase activation or ATRX-mutation leading to an alternative lengthening of telomeres phenotype (ALT). However, about 20% of glioblastomas lack alterations in TERTp and IDH. These tumors, designated TERTp
-IDH
glioblastomas, do not have well-established genetic biomarkers or defined mechanisms of telomere maintenance. Here we report the genetic landscape of TERTp
-IDH
glioblastoma and identify SMARCAL1 inactivating mutations as a novel genetic mechanism of ALT. Furthermore, we identify a novel mechanism of telomerase activation in glioblastomas that occurs via chromosomal rearrangements upstream of TERT. Collectively, our findings define novel molecular subgroups of glioblastoma, including a telomerase-positive subgroup driven by TERT-structural rearrangements (IDH
-TERT
), and an ALT-positive subgroup (IDH
-ALT) with mutations in ATRX or SMARCAL1.
Immunologic targeting of tumor-specific gene mutations may allow precise eradication of neoplastic cells without toxicity. Epidermal growth factor receptor variant III (EGFRvIII) is a constitutively ...activated and immunogenic mutation not expressed in normal tissues but widely expressed in glioblastoma multiforme (GBM) and other neoplasms.
A phase II, multicenter trial was undertaken to assess the immunogenicity of an EGFRvIII-targeted peptide vaccine and to estimate the progression-free survival (PFS) and overall survival (OS) of vaccinated patients with newly diagnosed EGFRvIII-expressing GBM with minimal residual disease. Intradermal vaccinations were given until toxicity or tumor progression was observed. Sample size was calculated to differentiate between PFS rates of 20% and 40% 6 months after vaccination.
There were no symptomatic autoimmune reactions. The 6-month PFS rate after vaccination was 67% (95% CI, 40% to 83%) and after diagnosis was 94% (95% CI, 67% to 99%; n = 18). The median OS was 26.0 months (95% CI, 21.0 to 47.7 months). After adjustment for age and Karnofsky performance status, the OS of vaccinated patients was greater than that observed in a control group matched for eligibility criteria, prognostic factors, and temozolomide treatment (hazard ratio, 5.3; P = .0013; n = 17). The development of specific antibody (P = .025) or delayed-type hypersensitivity (P = .03) responses to EGFRvIII had a significant effect on OS. At recurrence, 82% (95% CI, 48% to 97%) of patients had lost EGFRvIII expression (P < .001).
EGFRvIII-targeted vaccination in patients with GBM warrants investigation in a phase III, randomized trial.
The prognosis for patients with recurrent glioblastoma multiforme is poor, with a median survival of 3 to 6 months. We performed a phase II trial of bevacizumab, a monoclonal antibody to vascular ...endothelial growth factor, in combination with irinotecan.
This phase II trial included two cohorts of patients. The initial cohort, comprising 23 patients, received bevacizumab at 10 mg/kg plus irinotecan every 2 weeks. The dose of irinotecan was based on the patient's anticonvulsant: Patients taking enzyme-inducing antiepileptic drugs (EIAEDs) received 340 mg/m2, and patients not taking EIAEDs received 125 mg/m2. After this regimen was deemed safe and effective, the irinotecan schedule was changed to an accepted brain tumor regimen of four doses in 6 weeks, in anticipation of a phase III randomized trial of irinotecan versus irinotecan and bevacizumab. The second cohort, comprising 12 patients, received bevacizumab 15 mg/kg every 21 days and irinotecan on days 1, 8, 22, and 29. Each cycle was 6 weeks long and concluded with patient evaluations, including magnetic resonance imaging.
The 6-month progression-free survival among all 35 patients was 46% (95% CI, 32% to 66%). The 6-month overall survival was 77% (95% CI, 64% to 92%). Twenty of the 35 patients (57%; 95% CI, 39% to 74%) had at least a partial response. One patient developed a CNS hemorrhage, which occurred in his 10th cycle. Four patients developed thromboembolic complications (deep venous thrombosis and/or pulmonary emboli).
Bevacizumab and irinotecan is an effective treatment for recurrent glioblastoma multiforme and has moderate toxicity.
Intracerebral hemorrhage (ICH) is a subtype of stoke that may cause significant morbidity and mortality. Brain injury due to ICH initially occurs within the first few hours as a result of mass effect ...due to hematoma formation. However, there is increasing interest in the mechanisms of secondary brain injury as many patients continue to deteriorate clinically despite no signs of rehemorrhage or hematoma expansion. This continued insult after primary hemorrhage is believed to be mediated by the cytotoxic, excitotoxic, oxidative, and inflammatory effects of intraparenchymal blood. The main factors responsible for this injury are thrombin and erythrocyte contents such as hemoglobin. Therapies including thrombin inhibitors, N-methyl-D-aspartate antagonists, chelators to bind free iron, and antiinflammatory drugs are currently under investigation for reducing this secondary brain injury. This review will discuss the molecular mechanisms of brain injury as a result of intraparenchymal blood, potential targets for therapeutic intervention, and treatment strategies currently in development.
After stimulation, dendritic cells (DCs) mature and migrate to draining lymph nodes to induce immune responses. As such, autologous DCs generated ex vivo have been pulsed with tumour antigens and ...injected back into patients as immunotherapy. While DC vaccines have shown limited promise in the treatment of patients with advanced cancers including glioblastoma, the factors dictating DC vaccine efficacy remain poorly understood. Here we show that pre-conditioning the vaccine site with a potent recall antigen such as tetanus/diphtheria (Td) toxoid can significantly improve the lymph node homing and efficacy of tumour-antigen-specific DCs. To assess the effect of vaccine site pre-conditioning in humans, we randomized patients with glioblastoma to pre-conditioning with either mature DCs or Td unilaterally before bilateral vaccination with DCs pulsed with Cytomegalovirus phosphoprotein 65 (pp65) RNA. We and other laboratories have shown that pp65 is expressed in more than 90% of glioblastoma specimens but not in surrounding normal brain, providing an unparalleled opportunity to subvert this viral protein as a tumour-specific target. Patients given Td had enhanced DC migration bilaterally and significantly improved survival. In mice, Td pre-conditioning also enhanced bilateral DC migration and suppressed tumour growth in a manner dependent on the chemokine CCL3. Our clinical studies and corroborating investigations in mice suggest that pre-conditioning with a potent recall antigen may represent a viable strategy to improve anti-tumour immunotherapy.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, SBMB, SIK, UILJ, UKNU, UL, UM, UPUK
Purpose: Recurrent grade III-IV gliomas have a dismal prognosis with minimal improvements in survival seen following currently available
salvage therapy. This study was conducted to determine if the ...combination of a novel antiangiogenic therapy, bevacizumab,
and a cytotoxic agent, irinotecan, is safe and effective for patients with recurrent grade III-IV glioma.
Experimental Design: We conducted a phase II trial of bevacizumab and irinotecan in adults with recurrent grade III-IV glioma. Patients with evidence
of intracranial hemorrhage on initial brain magnetic resonance imaging were excluded. Patients were scheduled to receive bevacizumab
and irinotecan i.v. every 2 weeks of a 6-week cycle. Bevacizumab was administered at 10 mg/kg. The dose of irinotecan was
determined based on antiepileptic use: patients taking enzyme-inducing antiepileptic drugs received 340 mg/m 2 , whereas patients not taking enzyme-inducing antiepileptic drugs received 125 mg/m 2 . Toxicity and response were assessed.
Results: Thirty-two patients were assessed (23 with grade IV glioma and 9 with grade III glioma). Radiographic responses were noted
in 63% (20 of 32) of patients (14 of 23 grade IV patients and 6 of 9 grade III patients). The median progression-free survival
was 23 weeks for all patients (95% confidence interval, 15-30 weeks; 20 weeks for grade IV patients and 30 weeks for grade
III patients). The 6-month progression-free survival probability was 38% and the 6-month overall survival probability was
72%. No central nervous system hemorrhages occurred, but three patients developed deep venous thromboses or pulmonary emboli,
and one patient had an arterial ischemic stroke.
Conclusions: The combination of bevacizumab and irinotecan is an active regimen for recurrent grade III-IV glioma with acceptable toxicity.
Patients with glioblastoma have less than 15-month median survival despite surgical resection, high-dose radiation, and chemotherapy with temozolomide. We previously demonstrated that targeting ...cytomegalovirus pp65 using dendritic cells (DC) can extend survival and, in a separate study, that dose-intensified temozolomide (DI-TMZ) and adjuvant granulocyte macrophage colony-stimulating factor (GM-CSF) potentiate tumor-specific immune responses in patients with glioblastoma. Here, we evaluated pp65-specific cellular responses following DI-TMZ with pp65-DCs and determined the effects on long-term progression-free survival (PFS) and overall survival (OS).
Following standard-of-care, 11 patients with newly diagnosed glioblastoma received DI-TMZ (100 mg/m
/d × 21 days per cycle) with at least three vaccines of pp65 lysosome-associated membrane glycoprotein mRNA-pulsed DCs admixed with GM-CSF on day 23 ± 1 of each cycle. Thereafter, monthly DI-TMZ cycles and pp65-DCs were continued if patients had not progressed.
Following DI-TMZ cycle 1 and three doses of pp65-DCs, pp65 cellular responses significantly increased. After DI-TMZ, both the proportion and proliferation of regulatory T cells (Tregs) increased and remained elevated with serial DI-TMZ cycles. Median PFS and OS were 25.3 months 95% confidence interval (CI), 11.0-∞ and 41.1 months (95% CI, 21.6-∞), exceeding survival using recursive partitioning analysis and matched historical controls. Four patients remained progression-free at 59 to 64 months from diagnosis. No known prognostic factors age, Karnofsky performance status (KPS),
mutation, and
promoter methylation predicted more favorable outcomes for the patients in this cohort.
Despite increased Treg proportions following DI-TMZ, patients receiving pp65-DCs showed long-term PFS and OS, confirming prior studies targeting cytomegalovirus in glioblastoma.
.
Frequent mutations in isocitrate dehydrogenase 1 and 2 (IDH1 and IDH2) and the promoter of telomerase reverse transcriptase (TERT) represent two significant discoveries in glioma genomics. ...Understanding the degree to which these two mutations co-occur or occur exclusively of one another in glioma subtypes presents a unique opportunity to guide glioma classification and prognosis. We analyzed the relationship between overall survival (OS) and the presence of IDH1/2 and TERT promoter mutations in a panel of 473 adult gliomas. We hypothesized and show that genetic signatures capable of distinguishing among several types of gliomas could be established providing clinically relevant information that can serve as an adjunct to histopathological diagnosis. We found that mutations in the TERT promoter occurred in 74.2% of glioblastomas (GBM), but occurred in a minority of Grade II-III astrocytomas (18.2%). In contrast, IDH1/2 mutations were observed in 78.4% of Grade II-III astrocytomas, but were uncommon in primary GBM. In oligodendrogliomas, TERT promoter and IDH1/2 mutations co-occurred in 79% of cases. Patients whose Grade III-IV gliomas exhibit TERT promoter mutations alone predominately have primary GBMs associated with poor median OS (11.5 months). Patients whose Grade III-IV gliomas exhibit IDH1/2 mutations alone predominately have astrocytic morphologies and exhibit a median OS of 57 months while patients whose tumors exhibit both TERT promoter and IDH1/2 mutations predominately exhibit oligodendroglial morphologies and exhibit median OS of 125 months. Analyzing gliomas based on their genetic signatures allows for the stratification of these patients into distinct cohorts, with unique prognosis and survival.
Conventional therapies for glioblastoma multiforme (GBM) fail to target tumor cells exclusively, such that their efficacy
is ultimately limited by nonspecific toxicity. Immunologic targeting of ...tumor-specific gene mutations, however, may allow
more precise eradication of neoplastic cells. The epidermal growth factor receptor variant III (EGFRvIII) is a consistent
and tumor-specific mutation widely expressed in GBMs and other neoplasms. The safety and immunogenicity of a dendritic cell
(DC)–based vaccine targeting the EGFRvIII antigen was evaluated in this study. Adults with newly diagnosed GBM, who had undergone
gross-total resection and standard conformal external beam radiotherapy, received three consecutive intradermal vaccinations
with autologous mature DCs pulsed with an EGFRvIII-specific peptide conjugated to keyhole limpet hemocyanin. The dose of DCs
was escalated in cohorts of three patients. Patients were monitored for toxicity, immune response, radiographic and clinical
progression, and death. No allergic reactions or serious adverse events were seen. Adverse events were limited to grade 2
toxicities. The maximum feasible dose of antigen-pulsed mature DCs was reached at 5.7 × 10 7 ± 2.9 × 10 7 SD without dose-limiting toxicity. EGFRvIII-specific immune responses were evident in most patients. The mean time from histologic
diagnosis to vaccination was 3.6 ± 0.6 SD months. Median time to progression from vaccination was 6.8 months 95% confidence
interval (C.I. 95 ), 2.5–8.8, and median survival time from vaccination was 18.7 months (C.I. 95 , 14.5–25.6). Overall median survival from time of histologic diagnosis was 22.8 months (C.I. 95 , 17.5–29). This study establishes the EGFRvIII mutation as a safe and immunogenic tumor-specific target for immunotherapy.
Mol Cancer Ther 2009;8(10):2773–9
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