Jessica Wenthe

Shaping the tumor stroma and sparking immune activation by CD40 and 4-1BB signaling induced by an armed oncolytic virus.

Purpose: Pancreatic cancer is a severe indication with short expected survival despite surgery and/or combination chemotherapeutics. Checkpoint blockade antibodies are approved for several cancer indications, but pancreatic cancer has remained refractory. However, there are clinical data suggesting that stimulation of the CD40 pathway may be of interest for these patients. Oncolytic viruses armed with immunostimulatory genes represent an interesting approach. Herein, we present LOAd703, a designed adenovirus armed with trimerized CD40L and 4-1BBL that activates the CD40 and 4-1BB pathways, respectively. As many cells in the tumor stroma, including stellate cells and the infiltrating immune cells, express CD40 and some 4-1BB, we hypothesize that LOAd703 activates immunity and simultaneously modulates the biology of the tumor stroma. Experimental Design: Tumor, stellate, endothelial, and immune cells were infected by LOAd703 and investigated by flow cytometry, proteomics, and functional analyses. Results: LOAd703-infected pancreatic cell lines were killed by oncolysis, and the virus was more effective than standard-of-care gemcitabine. In in vivo xenograft models, LOAd703 efficiently reduced established tumors and could be combined with gemcitabine for additional effect. Infected stellate and tumor cells reduced factors that promote tumor growth (Spp-1, Gal-3, HGF, TGFβ and collagen type I), while chemokines were increased. Molecules involved in lymphocyte migration were upregulated on infected endothelial cells. Dendritic cells were robustly stimulated by LOAd703 to produce costimulators, cytokines and chemokines, and such DCs potently expanded both antigen-specific T cells and NK cells. Conclusions: LOAd703 is a potent immune activator that modulates the stroma to support antitumor responses. Clin Cancer Res; 23(19); 5846–57. ©2017 AACR.

516. A Novel Oncolytic Adenovirus Expressing Tumor Microenvironment Stimulators to Evoke and Facilitate Anti-Tumor Immune Responses

A Novel Oncolytic Adenovirus Expressing Tumor Microenvironment Stimulators to Evoke and Facilitate Anti-Tumor Immune Responses

A Phase I/IIa Trial Using CD19-Targeted Third-Generation CAR T Cells for Lymphoma and Leukemia

Purpose: The chimeric antigen receptor (CAR) T-cell therapy has been effective for patients with CD19+ B-cell malignancies. Most studies have investigated the second-generation CARs with either CD28 or 4-1BB costimulatory domains in the CAR receptor. Here, we describe the first clinical phase I/IIa trial using third-generation CAR T cells targeting CD19 to evaluate safety and efficacy. Patients and Methods: Fifteen patients with B-cell lymphoma or leukemia were treated with CAR T cells. The patients with lymphoma received chemotherapy during CAR manufacture and 11 of 15 were given low-dose cyclophosphamide and fludarabine conditioning prior to CAR infusion. Peripheral blood was sampled before and at multiple time points after CAR infusion to evaluate the persistence of CAR T cells and for immune profiling, using quantitative PCR, flow cytometry, and a proteomic array. Results: Treatment with third-generation CAR T cells was generally safe with 4 patients requiring hospitalization due to adverse reactions. Six of the 15 patients had initial complete responses [4/11 lymphoma and 2/4 acute lymphoblastic leukemia (ALL)], and 3 of the patients with lymphoma were in remission at 3 months. Two patients are still alive. Best predictor of response was a good immune status prior to CAR infusion with high IL12, DC-Lamp, Fas ligand, and TRAIL. Responding patients had low monocytic myeloid-derived suppressor cells (MDSCs; CD14+CD33+HLA−DR−) and low levels of IL6, IL8, NAP3, sPDL1, and sPDL2. Conclusions: Third-generation CARs may be efficient in patients with advanced B-cell lymphoproliferative malignancy with only modest toxicity. Immune profiling pre- and posttreatment can be used to find response biomarkers.

Local irradiation does not enhance the effect of immunostimulatory AdCD40L gene therapy combined with low dose cyclophosphamide in melanoma patients

Background AdCD40L is an immunostimulatory gene therapy under evaluation for advanced melanoma, including ocular melanoma. Herein, we present the final data of a Phase I/IIa trial using AdCD40L alone or in combination with low dose cyclophosphamide +/- radiation therapy. Methods AdCD40L is a replication-deficient adenovirus carrying the gene for CD40 ligand (CD40L). Twenty-four patients with advanced melanoma were enrolled and treated with AdCD40L monotherapy, or combined with cyclophosphamide +/- single fraction radiotherapy. The patients were monitored for 10 weeks using immunological and radiological evaluations and thereafter for survival. Results AdCD40L treatment was safe and well tolerated both alone and in combination with cyclophosphamide as well as local radiotherapy. Four out of twenty-four patients had >1 year survival. Addition of cyclophosphamide was beneficial but adding radiotherapy did not further extend survival. High initial plasma levels of IL12 and MIP3b correlated to overall survival, whereas IL8 responses post-treatment correlated negatively with survival. Interestingly, antibody reactions to the virus correlated negatively with post IL6 and pre IL1b levels in blood. Conclusions AdCD40L was safely administered to patients and effect was improved by cyclophosphamide but not by radiotherapy. Immune activation profile at baseline may predict responders better than shortly after treatment.

Abstract 3662: Activation of CD40 while inhibiting IL6/STAT3 using oncolytic viruses induces mature DCs with high cytokine production but blocks PDL1 expression

The tumor microenvironment (TME) consists of tumor cells and stroma, including fibroblasts, blood vessels, immune cells and extracellular matrix. The TME supports tumor progression, metastasis as well as resistance to cancer therapeutics. In pancreatic cancer, the TME is dense due to overproduction of collagen and the tumor is infiltrated with suppressive myeloid cells such as M2 macrophages and myeloid suppressor cells. One key regulator of myeloid cells is CD40, a receptor expressed on a variety of cell types. CD40/CD40L signaling results in production of cytokines and chemokines by myeloid cells but also endothelial and epithelial cells to alert the immune system of immediate danger. 4-1BB is expressed by lymphocytes and dendritic cells (DCs). Stimulation via 4-1BBL drives lymphocyte expansion and regulates memory formation. IL6 signaling leads to STAT3 phosphorylation in myeloid cells and tumor cells leading to suppressive phenotypes, tumor proliferation, and angiogenesis. Further, STAT3 signaling enhances production of TGFb, which in turn leads to overexpression of collagen. We have constructed a family of oncolytic adenoviruses (LOAd) activating the CD40, 4-1BB and/or inhibiting IL6 signaling. The LOAd viruses (-, 700, 703, 713) were investigated for their capacity to activate human monocyte-derived DCs as well as their effect on pancreatic tumor cells and stroma (fibroblastic stellate cells, endothelial cells) using flow cytometry, MTS assay and ProSeek Proteomics. The LOAd viruses expressing a trimerized CD40L, 4-1BBL and/or a scFv IL6R showed efficient oncolysis of tumor cells but primary stellate cells were unaffected. However, stellate cells reduced tumor-promoting factors such as FGF5, PlGF, amphiregulin, Gal3, TGFb and collagen type I. Dendritic cells increased costimulators, cytokines as well as chemokines but PDL1 was not expressed when IL6/STAT3 was blocked. Infected endothelial cells upregulated receptors important for lymphocyte transmigration (ICAM, VCAM and E-Selectin). Taken together, our data demonstrates that it is possible to utilize oncolytic adenoviruses to spark immune activation at the same time changing biological processes via STAT3 blockade and/or CD40/4-1BB pathway activation to reduce factors that promotes tumor progression. Citation Format: Emma Eriksson, Ioanna Milenova, Jessica Wenthe, Anna Dimberg, Rafael Moreno, Gustav Ullenhag, Ramon Alemany, Angelica Loskog. Activation of CD40 while inhibiting IL6/STAT3 using oncolytic viruses induces mature DCs with high cytokine production but blocks PDL1 expression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3662. doi:10.1158/1538-7445.AM2017-3662

T cell stimulation with different cytokines results in distinct phenotypes and cytotoxic activity of CD19-specific CART cells

T cell stimulation with different cytokines results in distinct phenotypes and cytotoxic activity of CD19-specific CART cells

748. A Clinical Trial Using Third Generation CD19 Targeting CAR T Cells for Relapsed Lymphoma and Leukemia

A Clinical Trial Using Third Generation CD19 Targeting CAR T Cells for Relapsed Lymphoma and Leukemia