A Phase I Study of Autologous Dendritic Cell Vaccine Pulsed with Allogeneic Stem-like Cell Line Lysate in Patients with Newly Diagnosed or Recurrent Glioblastoma.

PURPOSE: Glioblastoma (GBM) is a heterogeneous malignancy with multiple subpopulations of cancer cells present within any tumor. We present the results of a phase I clinical trial using an autologous dendritic cell (DC) vaccine pulsed with lysate derived from a GBM stem-like cell line. PATIENTS AND METHODS: Patients with newly diagnosed and recurrent GBM were enrolled as separate cohorts. Eligibility criteria included a qualifying surgical resection or minimal tumor size, ≤ 4-mg dexamethasone daily dose, and Karnofsky score ≥70. Vaccine treatment consisted of two phases: an induction phase with vaccine given weekly for 4 weeks, and a maintenance phase with vaccines administered every 8 weeks until depletion of supply or disease progression. Patients with newly diagnosed GBM also received standard-of-care radiation and temozolomide. The primary objective for this open-label, single-institution trial was to assess the safety and tolerability of the autologous DC vaccine. RESULTS: For the 11 patients with newly diagnosed GBM, median progression-free survival (PFS) was 8.75 months, and median overall survival was 20.36 months. For the 25 patients with recurrent GBM, median PFS was 3.23 months, 6-month PFS was 24%, and median survival was 11.97 months. A subset of patients developed a cytotoxic T-cell response as determined by an IFNγ ELISpot assay. CONCLUSIONS: In this trial, treatment of newly diagnosed and recurrent GBM with autologous DC vaccine pulsed with lysate derived from an allogeneic stem-like cell line was safe and well tolerated. Clinical outcomes add to the body of evidence suggesting that immunotherapy plays a role in the treatment of GBM.

A phase I trial of surgical resection with Gliadel Wafer placement followed by vaccination with dendritic cells pulsed with tumor lysate for patients with malignant glioma.

High grade gliomas are associated with poor prognosis and high mortality. Conventional treatments and management of high grade gliomas have shown little improvement in 5-year overall survival. This phase I trial evaluated the safety, immunogenicity, and potential synergy of surgical resection with Gliadel Wafer implantation, followed by autologous tumor lysate-pulsed dendritic cell (DC) vaccine in patients with malignant glioma. Primary end points of this study were safety and surrogate markers of immunogenicity, overall survival, and progression free survival. Following surgical resection, Gliadel Wafers were placed along the resection cavity. Patients subsequently received intradermal injections of autologous tumor lysate-pulsed DC vaccines 3 times at 2 week intervals. Treatment response was evaluated clinically and through MRI at regular intervals. Twenty-eight patients received Gliadel Wafers and DC vaccination: 11 newly diagnosed (8 glioblastoma [GBM], 2 anaplastic astrocytoma [AA], and 1 anaplastic oligodendroglioma [AO]) and 17 recurrent (15 GBMs, 1 AA, and 1 AO) high grade gliomas. Immunogenicity data was collected for 20 of the 28 patients. Five of 20 patients showed elevated IFN-γ responses following vaccination. Median progression-free survival and overall survival for all GBM patients in the trial from the start of vaccination were 3.6 months and 16.9 months respectively. Comparisons between vaccine responders and non-vaccine responders were not statistically significant. Adjuvant autologous dendritic cells pulsed with tumor-lysate following resection and Gliadel Wafer placement is safe, elicits modest immunogenicity and shows similar clinical outcomes in patients who had DC vaccination in previous studies.

Regulatable interleukin-12 gene therapy in patients with recurrent high-grade glioma: Results of a phase 1 trial.

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.

Isolated Extracranial Intraosseous Metastasis of an Intracranial Meningioma following Bevacizumab Therapy: Case Report and Review of the Literature.

Meningiomas account for a significant proportion of all primary intracranial tumors; distant metastasis is quite rare. We report a patient with resected, atypical meningioma. The patient's clinical course over 5 years included two craniotomies, a course of radiation, and a shortened course of bevacizumab. Only 5 months after starting bevacizumab, the patient developed an isolated left clavicular pathological fracture attributable to metastatic anaplastic meningioma. This constitutes the first report of meningioma with isolated extracranial intraosseous metastasis in the modern English literature and highlights concerns associated with the use of anti-angiogenic agents in promoting more invasive tumor phenotypes upon disease recurrence.

Do Long-Term Survivor Primary Glioblastoma Patients Harbor IDH1 Mutations?

BACKGROUND: Approximately 3 to 16% of glioblastoma multiforme (GBM) patients are considered long-term survivors (LTS: 3+ years). OBJECTIVE: Given the improved survival conferred by IDH1 mutations and the fact that these mutations are detected in 12% of newly diagnosed GBM cases, could long-term survivorship be explained by IDH1 mutation status? Our aim was to describe GBM LTS with IDH1 mutations and explore its association with overall survival (OS). METHODS: Records of 453 newly diagnosed adult GBM patients treated at a single institution from 2004 to 2010 were reviewed retrospectively for patients who survived at least 36 months postsurgery. Descriptive statistics for clinical characteristics, treatments received, and tumor biomarkers were reported. Estimates for progression-free survival (PFS) and OS were provided. RESULTS: Forty (8.8%) LTS GBM patients were identified, with a median age of 50 years and a median preoperative Karnofsky Performance Score (KPS) of 80. Most patients underwent near-total/gross-total resection (72.5%), postoperative radiation (97.5%), and adjuvant temozolomide (95%). PFS rates at 12, 36, 48, and 72 months were 67.5%, 40%, 32.7%, and 26.2%, respectively. Median OS has not yet been reached; however, the survival rate at 48 months was 62.1%. Among 35 patients with available tumor samples, only 8 (22.9%) had IDH1 mutations. No significant difference in median PFS was found between IDH1 mutation and wild-type patients (46.6 versus 26.3 months; p =0.45). CONCLUSIONS: Less than a quarter of our patients' long-term survivorship was associated with favorable IDH1 status. Therefore, IDH1 status does not explain most of the long-term survivorship in the temozolomide era.

Functionality of hypoxia-induced BAX expression in a human glioblastoma xenograft model.

The effectiveness of radiation therapy for human brain tumors is limited by the presence of radiation-resistant hypoxic cells. In order to improve patient outcomes, therapeutic methods that increase hypoxic cell killing must be developed. To investigate the possibility of using the hypoxic tumor microenvironment itself as a target for gene therapy, we stably transfected U-251 MG human glioblastoma cells with constructs containing the suicide gene Bax under the regulation of a nine-copy concatemer of hypoxia responsive elements (HREs). Previously, we demonstrated that the expression of BAX protein under anoxic conditions in transfected U-251 MG clones leads to increased cell killing in vitro. Our recent studies revealed that HIF-1alpha induction under anoxic conditions occurs prior to the increase in BAX expression, thereby implicating HIF-1 induction as the basis of BAX upregulation. To test the effect of BAX-mediated cell killing in vivo, we implanted five stably transfected clones subcutaneously into the flanks of athymic mice. Compared to nontransfected controls, tumor growth in four of five clones was significantly retarded. Histopathological analysis demonstrated decreased hypoxic fractions and increased amounts of apoptosis in clone-derived tumors. These results suggest that the tumor microenvironment is sufficiently hypoxic to trigger HRE-mediated cell killing via the BAX apoptotic pathway.