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Background While prophylactic human papillomavirus (HPV) vaccines will certainly reduce the incidence of HPV-associated cancers, these malignancies remain a major health issue. PDS0101 is a liposomal-based HPV therapeutic vaccine consisting of the immune activating cationic lipid R-DOTAP and HLA-unrestricted HPV16 peptides that has shown in vivo CD8+ T cell induction and safety in a phase I study. In this report, we have employed the PDS0101 vaccine with two immune modulators previously characterized in preclinical studies and which are currently in phase II clinical trials. Bintrafusp alfa (M7824) is a first-in-class bifunctional fusion protein composed of the extracellular domains of the transforming growth factor-β receptor type II (TGFβRII) fused to a human IgG1 monoclonal antibody blocking programmed cell death protein-1 ligand (PDL1), designed both as a checkpoint inhibitor and to bring the TGFβRII ‘trap’ to the tumor microenvironment (TME). NHS-interleukin-12 (NHS-IL12) is a tumor targeting immunocytokine designed to bring IL-12 to the TME and thus enhance the inflammatory Th1 response.Methods We employed TC-1 carcinoma (expressing HPV16 E6 and E7 and devoid of PDL1 expression) in a syngeneic mouse model in monotherapy and combination therapy studies to analyze antitumor effects and changes in immune cell types in the spleen and the TME.Results As a monotherapy, the PDS0101 vaccine generated HPV-specific T cells and antitumor activity in mice bearing HPV-expressing mEER oropharyngeal and TC-1 lung carcinomas. When used as a monotherapy in the TC-1 model, NHS-IL12 elicited antitumor effects as well as an increase in CD8+ T cells in the TME. When used as a monotherapy, bintrafusp alfa did not elicit antitumor effects or any increase in T cells in the TME. When all three agents were used in combination, maximum antitumor effects were observed, which correlated with increases in T cells and T-cell clonality in the TME.Conclusion These studies provide the rationale for the potential clinical use of combinations of agents that can (1) induce tumor-associated T-cell responses, (2) potentiate immune responses in the TME and (3) reduce immunosuppressive entities in the TME.

The lack of serial biopsies in patients with a range of carcinomas has been one obstacle in our understanding of the mechanism of action of immuno-oncology agents as well as the elucidation of mechanisms of resistance to these novel therapeutics. While much information can be obtained from studies conducted with syngeneic mouse models, these models have limitations, including that both tumor and immune cells being targeted are murine and that many of the immuno-oncology agents being evaluated are human proteins, and thus multiple administrations are hampered by host xenogeneic responses. Some of these limitations are being overcome by the use of humanized mouse models where human peripheral blood mononuclear cells (PBMC) are engrafted into immunosuppressed mouse strains. Bintrafusp alfa (M7824) is an innovative first-in-class bifunctional fusion protein composed of the extracellular domain of the TGF-βRII to function as a TGF-β “trap” fused to a human IgG1 antibody blocking PD-L1. A phase I clinical trial of bintrafusp alfa showed promising anti-tumor efficacy in heavily pretreated advanced solid tumors, and multiple clinical studies are currently ongoing. There is still much to learn regarding the mechanism of action of bintrafusp alfa, including its effects on both human immune cells in the periphery and in the tumor microenvironment (TME), and any temporal effects upon multiple administrations. By using the NSG-β2m−/− mouse strain humanized with PBMC, we demonstrate here for the first time: (a) the effects of bintrafusp alfa administration on human immune cells in the periphery vs. the TME using three different human xenograft models; (b) temporal effects upon multiple administrations of bintrafusp alfa; (c) phenotypic changes induced in the TME, and (d) variations observed in the use of multiple different PBMC donors. Also discussed are the similarities and differences in the data thus far obtained employing murine syngeneic models, from clinical trials, and in the use of this humanized mouse model. The results described here may guide the future use of this agent or similar immunotherapy agents as monotherapies or in combination therapy studies.

Here we describe a novel bifunctional fusion protein, designated N-809. This molecule comprises the IL-15/IL15Rα superagonist complex containing the Fc-domain of IgG1 (N-803, formerly designated as ALT-803) fused to two single chain anti-PD-L1 domains. The fully human IgG1 portion of the N-809 molecule was designed to potentially mediate antibody dependent cellular cytotoxicity (ADCC). The studies reported here show that N-809 has the same ability to bind PD-L1 as an anti-PD-L1 monoclonal antibody. RNAseq studies show the ability of N-809 to alter the expression of an array of genes of both CD4+ and CD8+ human T cells, and to enhance their proliferation; CD8+ T cells exposed to N-809 also have enhanced ability to lyse human tumor cells. An array of genes was differentially expressed in human natural killer (NK) cells following N-809 treatment, and there was increased expression of several surface activating receptors; there was, however, no increase in the expression of inhibitory receptors known to be upregulated in exhausted NK cells. N-809 also increased the cytotoxic potential of NK cells, as shown by increased expression of granzyme B and perforin. The lysis of several tumor cell types was increased when either NK cells or tumor cells were exposed to N-809. Similarly, the highest level of ADCC was seen when both NK cells (from donors or cancer patients) and tumor cells were exposed to N-809. These studies thus demonstrate the multi-functionality of this novel agent.

Background As accessible diagnostic approaches fail to differentiate between ulcerative colitis (UC) and Crohn's colitis (CC) in one-third of patients with predominantly colonic inflammatory bowel disease (IBD), leading to inappropriate therapy, we aim to investigate the serum cytokine levels in these patients in search of molecular biometric markers delineating UC from CC. Methods We measured 38 cytokines, chemokines, and growth factors using magnetic-bead-based multiplex immunoassay in 25 UC patients, 28 CC patients, and 30 controls. Our results are compared with those from a review of current literature regarding advances in serum cytokine profiles and associated challenges preventing their use for diagnostic/prognostic purposes. Results Univariate analysis showed statistically significant increases of eotaxin, GRO, and TNF-α in UC patients compared to controls (Ctrl); interferon γ, interleukin (IL)-6, and IL-7 in CC group compared to Ctrl; and IL-8 in both UC and CC versus Ctrl. No cytokines were found to be different between UC and CC. A generalized linear model identified combinations of cytokines, allowing the identification of UC and CC patients, with area under the curve (AUC) = 0.936, as determined with receiver operating characteristic (ROC) analysis. Conclusions The current knowledge available about circulating cytokines in IBD is often contradictory. The development of an evidence-based tool using cytokines for diagnostic accuracy is still preliminary.

There are approximately 44,000 cases of human papillomavirus–associated (HPV-associated) cancer each year in the United States, most commonly caused by HPV types 16 and 18. Prophylactic vaccines successfully prevent healthy people from acquiring HPV infections via HPV-specific antibodies. In order to treat established HPV-associated malignancies, however, new therapies are necessary. Multiple recombinant gorilla adenovirus HPV vaccine constructs were evaluated in NSG-β2m–/– peripheral blood mononuclear cell–humanized mice bearing SiHa, a human HPV16+ cervical tumor, and/or in the syngeneic HPV16+ TC-1 model. PRGN-2009 is a therapeutic gorilla adenovirus HPV vaccine containing multiple cytotoxic T cell epitopes of the viral oncoproteins HPV 16/18 E6 and E7, including T cell enhancer agonist epitopes. PRGN-2009 treatment reduced tumor volume and increased CD8+ and CD4+ T cells in the tumor microenvironment of humanized mice bearing the human cervical tumor SiHa. PRGN-2009 monotherapy in the syngeneic TC-1 model also reduced tumor volumes and weights, generated high levels of HPV16 E6–specific T cells, and increased multifunctional CD8+ and CD4+ T cells in the tumor microenvironment. These studies provide the first evaluation to our knowledge of a therapeutic gorilla adenovirus HPV vaccine, PRGN-2009, showing promising preclinical antitumor efficacy and induction of HPV-specific T cells, along with the rationale for its evaluation in clinical trials.