Radiological Evaluation of Newly Diagnosed Non-Brainstem Pediatric High-Grade Glioma in the HERBY Phase II Trial.

PURPOSE: The HERBY trial evaluated the benefit of the addition of the antiangiogenic agent Bevacizumab (BEV) to radiotherapy/temozolomide (RT/TMZ) in pediatric patients with newly diagnosed non-brainstem high-grade glioma (HGG). The work presented here aims to correlate imaging characteristics and outcome measures with pathologic and molecular data. EXPERIMENTAL DESIGN: Radiological, pathologic, and molecular data were correlated with trial clinical information to retrospectively re-evaluate event-free survival (EFS) and overall survival (OS). RESULTS: One-hundred thirteen patients were randomized to the RT/TMZ arm (n = 54) or the RT/TMZ+BEV (BEV arm; n = 59). The tumor arose in the cerebral hemispheres in 68 patients (Cerebral group) and a midline location in 45 cases (Midline group). Pathologic diagnosis was available in all cases and molecular data in 86 of 113. H3 K27M histone mutations were present in 23 of 32 Midline cases and H3 G34R/V mutations in 7 of 54 Cerebral cases. Total/near-total resection occurred in 44 of 68 (65%) Cerebral cases but in only 5 of 45 (11%) Midline cases (P < 0.05). Leptomeningeal metastases (27 cases, 13 with subependymal spread) at relapse were more frequent in Midline (17/45) than in Cerebral tumors (10/68, P < 0.05). Mean OS (14.1 months) and EFS (9.0 months) in Midline tumors were significantly lower than mean OS (20.7 months) and EFS (14.9 months) in Cerebral tumors (P < 0.05). Pseudoprogression occurred in 8 of 111 (6.2%) cases. CONCLUSIONS: This study has shown that the poor outcome of midline tumors (compared with cerebral) may be related to (1) lesser surgical resection, (2) H3 K27M histone mutations, and (3) higher leptomeningeal dissemination.

Phase II, Open-Label, Randomized, Multicenter Trial (HERBY) of Bevacizumab in Pediatric Patients With Newly Diagnosed High-Grade Glioma.

Purpose Bevacizumab (BEV) is approved in more than 60 countries for use in adults with recurrent glioblastoma. We evaluated the addition of BEV to radiotherapy plus temozolomide (RT+TMZ) in pediatric patients with newly diagnosed high-grade glioma (HGG). Methods The randomized, parallel group, multicenter, open-label HERBY trial ( ClinicalTrials.gov identifier: NCT01390948) enrolled patients age ≥ 3 years to ≤ 18 years with localized, centrally neuropathology-confirmed, nonbrainstem HGG. Eligible patients were randomly assigned to receive RT + TMZ (RT: 1.8 Gy, 5 days per week, and TMZ: 75 mg/m2 per day for 6 weeks; 4-week treatment break; then up to 12 × 28-day cycles of TMZ [cycle 1: 150 mg/m2 per day, days 1 to 5; cycles 2 to 12: 200 mg/m2 per day, days 1 to 5]) with or without BEV (10 mg/kg every 2 weeks). The primary end point was event-free survival (EFS) as assessed by a central radiology review committee that was blinded to treatment. We report findings of EFS at 12 months after the enrollment of the last patient. Results One hundred twenty-one patients were enrolled (RT+TMZ [n = 59]; BEV plus RT+TMZ [n = 62]). Central radiology review committee-assessed median EFS did not differ significantly between treatment groups (RT+TMZ, 11.8 months; 95% CI, 7.9 to 16.4 months; BEV plus RT+TMZ, 8.2 months; 95% CI, 7.8 to 12.7 months; hazard ratio, 1.44; P = .13 [stratified log-rank test]). In the overall survival analysis, the addition of BEV did not reduce the risk of death (hazard ratio, 1.23; 95% CI, 0.72 to 2.09). More patients in the BEV plus RT+TMZ group versus the RT+TMZ group experienced one or more serious adverse events (n = 35 [58%] v n = 27 [48%]), and more patients who received BEV discontinued study treatment as a result of adverse events (n = 13 [22%] v n = 3 [5%]). Conclusion Adding BEV to RT+TMZ did not improve EFS in pediatric patients with newly diagnosed HGG. Our findings were not comparable to those of previous adult trials, which highlights the importance of performing pediatric-specific studies.

Pre-clinical evaluation of the MDM2-p53 antagonist RG7388 alone and in combination with chemotherapy in neuroblastoma.

Neuroblastoma is a predominantly p53 wild-type (wt) tumour and MDM2-p53 antagonists offer a novel therapeutic strategy for neuroblastoma patients. RG7388 (Roche) is currently undergoing early phase clinical evaluation in adults. This study assessed the efficacy of RG7388 as a single-agent and in combination with chemotherapies currently used to treat neuroblastoma in a panel of neuroblastoma cell lines. RG7388 GI50 concentrations were determined in 21 p53-wt and mutant neuroblastoma cell lines of varying MYCN, MDM2 and p14(ARF) status, together with MYCN-regulatable Tet21N cells. The primary determinant of response was the presence of wt p53, and overall there was a >200-fold difference in RG7388 GI50 concentrations for p53-wt versus mutant cell lines. Tet21N MYCN+ cells were significantly more sensitive to RG7388 compared with MYCN- cells. Using median-effect analysis in 5 p53-wt neuroblastoma cell lines, selected combinations of RG7388 with cisplatin, doxorubicin, topotecan, temozolomide and busulfan were synergistic. Furthermore, combination treatments led to increased apoptosis, as evident by higher caspase-3/7 activity compared to either agent alone. These data show that RG7388 is highly potent against p53-wt neuroblastoma cells, and strongly supports its further evaluation as a novel therapy for patients with high-risk neuroblastoma and wt p53 to potentially improve survival and/or reduce toxicity.

Immunotherapy of high-risk acute leukemia with a recipient (autologous) vaccine expressing transgenic human CD40L and IL-2 after chemotherapy and allogeneic stem cell transplantation.

CD40L generates immune responses in leukemia-bearing mice, an effect that is potentiated by IL-2. We studied the feasibility, safety, and immunologic efficacy of an IL-2- and CD40L-expressing recipient-derived tumor vaccine consisting of leukemic blasts admixed with skin fibroblasts transduced with adenoviral vectors encoding human IL-2 (hIL-2) and hCD40L. Ten patients (including 7 children) with high-risk acute myeloid (n = 4) or lymphoblastic (n = 6) leukemia in cytologic remission (after allogeneic stem cell transplantation [n = 9] or chemotherapy alone [n = 1]) received up to 6 subcutaneous injections of the IL-2/CD40L vaccine. None of the patients were receiving immunosuppressive drugs. No severe adverse reactions were noted. Immunization produced a 10- to 890-fold increase in the frequencies of major histocompatibility complex (MHC)-restricted T cells reactive against recipient-derived blasts. These leukemia-reactive T cells included both T-cytotoxic/T-helper 1 (Th1) and Th2 subclasses, as determined from their production of granzyme B, interferon-gamma, and interleukin-5. Two patients produced systemic IgG antibodies that bound to their blasts. Eight patients remained disease free for 27 to 62 months after treatment (5-year overall survival, 90%). Thus, even in heavily treated patients, including recipients of allogeneic stem cell transplants, recipient-derived antileukemia vaccines can induce immune responses reactive against leukemic blasts. This approach may be worthy of further study, particularly in patients with a high risk of relapse.

Vaccine therapies for pediatric malignancies.

Cancer vaccines are examples of active immunotherapy. In pediatric malignancy such active strategies may be particularly problematic because of immune suppression produced by the tumor or its intensive treatment with combined chemotherapy. Nonetheless, the expression of tumor-specific and tumor-associated antigens on a range of pediatric tumors has encouraged investigation of the approach in patients with either bulky or minimal residual disease. Here we describe promising results in neuroblastoma and acute leukemia, suing genetically modified whole cell vaccines, peptides, and dendritic cells. The difficulties of conducting and evaluating such studies in a pediatric population are also described, and a strategy for cancer vaccine development is outlined.

[Impact of regulations on translational research in cell and gene therapy: the American experience]. / Impact des réglementations sur la recherche de transfert en thérapie génique et cellulaire: l'exemple américain.

The increasing utilization of cell and gene therapy in the treatment of human diseases, particularly cancers, has led lawmakers to institute stringent rules to regulate this new area of medicine and optimally protect patients. Cell and gene therapy centers, often located within academic institutions, are becoming subject to rules previously applied only to pharmaceutical companies. Based on the US experience, we review here the regulations that currently regulate or are being proposed to cover cell and gene therapy centers. We describe the principles of good manufacturing practices, quality assurance and quality control and accreditation. Finally, we discuss the future of cell and gene therapy in the context of the increasingly rigorous regulatory environment implemented in the US.

Overexpression of the Notch ligand, Jagged-1, induces alloantigen-specific human regulatory T cells.

Graft-versus-host disease (GVHD) represents one of the major complications of allogeneic hematopoietic stem cell transplantation. Techniques to prevent GVHD have included ex vivo T-cell depletion of the graft or prolonged in vivo immunosuppression. Both reduce the frequency and severity of GVHD but also reduce T-cell-mediated graft-versus-malignancy effect, and increase the risk of infection. A major goal in transplantation is to prevent alloreactivity while preserving activity against tumors and infectious agents. We have used activation of the Notch pathway to try to generate T cells able to specifically regulate alloantigen responses. We used allogeneic Epstein-Barr virus lymphoblastoid B cells (EBV-LCLs) as stimulator cells. Such LCLs are excellent (allo) antigen-presenting cells and can be obtained in large numbers even from donors who have received extensive chemo/radiotherapy. We overexpressed a Notch ligand, Jagged-1, in these cells by adenoviral vector transduction. Stimulation of CD45RA+ naive T cells by Jagged-1 EBV-LCL reduces production of interferon-gamma, interleukin-2, and interleukin-5, but up-regulates transforming growth factor-beta 1 synthesis, consistent with induction of a regulatory T-cell phenotype. Transfer of these T cells to fresh lymphocyte cultures inhibits proliferative and cytotoxic immune responses to the priming alloantigens while sparing responses to third-party stimulator cells. Notch activation in the presence of alloantigen-presenting cells may therefore be a means of inducing specific regulatory T cells while preserving other T-cell functionality.

Bystander transfer of functional human CD40 ligand from gene-modified fibroblasts to B-chronic lymphocytic leukemia cells.

CD40 ligand (CD40L) is a good candidate molecule for the immunotherapy of B cell malignancies including B-chronic lymphocytic leukemia (B-CLL), because it may increase the capacity of the malignant cells to present tumor antigens. However, efforts to manipulate expression of the human CD40L (hCD40L) molecule have foundered on problems associated with lack of consistent gene transfer into the malignant target cells. We now describe a new, highly reproducible method for inducing hCD40L surface expression on malignant B cells, which is dependent on intercellular transfer of the hCD40L protein from donor gene-modified fibroblasts to patient tumor cells. Ten B-CLL samples were cocultured with MRC-5 fibroblasts (a human embryonic lung cell line) previously transduced with an adenoviral vector encoding the hCD40L gene. The malignant cells expressed high levels of surface hCD40L, B7-1, B7-2, and ICAM-1 after coculture. Upregulation of B7-1 and B7-2 was cycloheximide inhibitable and was a consequence of CD40 activation. However, inhibition of protein synthesis had no effect on the ability of B-CLL cells to acquire surface expression of hCD40L. hCD40L surface expression required cell-to-cell contact, but was independent of CD40 engagement. hCD40L transfer was not mediated by membrane fusion. The transferred hCD40L was functionally intact and B-CLL cells expressing this molecule induced increased interferon-gamma production from autologous peripheral blood T lymphocytes. This approach does not use any direct gene transfer to primary leukemia cells and can readily be scaled up for production of clinical B-CLL vaccines.

Occult orbital neuroblastoma detected after administration of an antitumor vaccine.

A 6-year-old girl with neuroblastoma developed swelling and erythema of her right upper eyelid following administration of an interleukin-2 and lymphotactin gene-modified allogeneic neuroblastoma cell vaccine. Computed tomography demonstrated a cystic lesion in the subperiosteal space. A biopsy of the mass showed necrotic neuroblastoma with minimal associated inflammation. To our knowledge, this case represents the first description of occult orbital metastases in a patient with neuroblastoma detected after administration of an antitumor vaccine.

Local and systemic effects of an allogeneic tumor cell vaccine combining transgenic human lymphotactin with interleukin-2 in patients with advanced or refractory neuroblastoma.

In murine models, transgenic chemokine-cytokine tumor vaccines overcome many of the limitations of single-agent immunotherapy by producing the sequence of T-cell attraction followed by proliferation. The safety and immunologic effects of this approach in humans were tested in 21 patients with relapsed or refractory neuroblastoma. They received up to 8 subcutaneous injections of a vaccine combining lymphotactin (Lptn)- and interleukin-2 (IL-2)-secreting allogeneic neuroblastoma cells in a dose-escalating scheme. Severe adverse reactions were limited to reversible panniculitis in 5 patients and bone pain in 1 patient. Injection-site biopsies revealed increased cellularity caused by infiltration of CD4+ and CD8+ lymphocytes, eosinophils, and Langerhans cells. Systemically, the vaccine produced a 2-fold (P =.035) expansion of CD4+ T cells, a 3.5-fold (P =.039) expansion of natural killer (NK) cells, a 2.1-fold (P =.014) expansion of eosinophils, and a 1.6-fold (P =.049) increase in serum IL-5. When restimulated in vitro by the immunizing cell line, T cells collected after vaccination showed a 2.3-fold increase (P =.02) of T-helper (TH2)-type CD3+IL-4+ cells. Supernatant collected from restimulated cells showed increased amounts of IL-4 (11.4-fold; P =.021) and IL-5 (8.7-fold; P =.002). Six patients had significant increases in NK cytolytic activity. Fifteen patients made immunoglobulin G (IgG) antibodies that bound to the immunizing cell line. Measurable tumor responses included complete remission in 2 patients and partial response in 1 patient. Hence, allogeneic tumor cell vaccines combining transgenic Lptn with IL-2 appear to have little toxicity in humans and can induce an antitumor immune response.