Tumor-infiltrating immune cells have been linked to prognosis and response to immunotherapy; however, the levels of distinct immune cell subsets and the signals that draw them into a tumor, such as the expression of antigen presenting machinery genes, remain poorly characterized. Here, we employ a gene expression-based computational method to profile the infiltration levels of 24 immune cell populations in 19 cancer types. We compare cancer types using an immune infiltration score and a T cell infiltration score and find that clear cell renal cell carcinoma (ccRCC) is among the highest for both scores. Using immune infiltration profiles as well as transcriptomic and proteomic datasets, we characterize three groups of ccRCC tumors: T cell enriched, heterogeneously infiltrated, and non-infiltrated. We observe that the immunogenicity of ccRCC tumors cannot be explained by mutation load or neo-antigen load, but is highly correlated with MHC class I antigen presenting machinery expression (APM). We explore the prognostic value of distinct T cell subsets and show in two cohorts that Th17 cells and CD8+ T/Treg ratio are associated with improved survival, whereas Th2 cells and Tregs are associated with negative outcomes. Investigation of the association of immune infiltration patterns with the subclonal architecture of tumors shows that both APM and T cell levels are negatively associated with subclone number. Our analysis sheds light on the immune infiltration patterns of 19 human cancers and unravels mRNA signatures with prognostic utility and immunotherapeutic biomarker potential in ccRCC.

In oncology, the “abscopal effect” refers to the therapeutic effect on a distant tumor resulting from the treatment of local tumor (e. g., ablation, injection, or radiation). Typically associated with radiation, the abscopal effect is thought to be mediated by a systemic antitumor immune response that is induced by two concurrent changes at the treated tumor: (1) the release of tumor antigens and (2) the exposure of damage-associated molecular patterns. Therapies that produce these changes are associated with immunogenic cell death (ICD). Some interventions have been shown to cause an abscopal effect without inducing the release of tumor antigens, suggesting that release of tumor antigens at baseline plays a significant role in mediating the abscopal effect. With tumor antigens already present, therapies that target activation of APCs alone may be sufficient to enhance the abscopal effect. Here, we discuss two therapies targeted at APC activation, TLR9 and CD40 agonists, and their use in the clinic to enhance the abscopal effect.

The liver tumor immune microenvironment has been thought to possess a critical role in the development and progression of hepatocellular carcinoma (HCC). Despite the approval of immune checkpoint inhibitors (ICIs), such as programmed cell death receptor 1 (PD-1)/programmed cell death ligand 1 (PD-L1) and cytotoxic T lymphocyte associated protein 4 (CTLA-4) inhibitors, for several types of cancers, including HCC, liver metastases have shown evidence of resistance or poor response to immunotherapies. Radiation therapy (RT) has displayed evidence of immunosuppressive effects through the upregulation of immune checkpoint molecules post-treatment. However, it was revealed that the limitations of ICIs can be overcome through the use of RT, as it can reshape the liver immune microenvironment. Moreover, ICIs are able to overcome the RT-induced inhibitory signals, effectively restoring anti-tumor activity. Owing to the synergetic effect believed to arise from the combination of ICIs with RT, several clinical trials are currently ongoing to assess the efficacy and safety of this treatment for patients with HCC.

Background: Tumor-selective oncolytic viral vectors are promising anticancer therapeutics; however, challenges with dosing and potency in advanced/metastatic cancers have limited efficacy and usage. NG-350A is a next-generation blood-stable adenoviral vector engineered to express an agonist anti-cluster of differentiation (CD)40 antibody without affecting tumor-selectivity and oncolytic potency. Methods: Intravenous and intratumoral (IT) administration of NG-350A was assessed in a phase Ia/Ib study in patients with metastatic/advanced epithelial tumors (NCT03852511). Dose-escalation was performed separately for intravenous (four dose levels available, each with infusions on Days 1, 3 and 5 of a 57-day treatment period) and IT (single injection on D1 only or injections on Days 1, 8, 15 and 22) administration. The primary objective was safety and tolerability; secondary objectives included determining a recommended dose, pharmacokinetics, and immunogenicity. Results: In total, 25 heavily pretreated patients received NG-350A (16 with intravenous and 9 with IT administration). Intravenous and IT dosing were both well tolerated, with no evidence of transgene-related or off-target viral toxicity. Intravenous and IT dosing resulted in dose-dependent increases in systemic NG-350A C_max. Despite both routes of administration inducing anti-virus antibodies, sustained persistence of NG-350A in blood samples was observed up to 7 weeks after the last dose, particularly with higher intravenous dose levels. Delivery of NG-350A to tumors was demonstrated in biopsy samples following both routes of administration; a dose-dependent pattern was seen with intravenous infusion, with four patients remaining positive for vector DNA in biopsies at Day 57. Transgene messenger RNA from replicating NG-350A was detected in 5/12 patients with intravenous treatment and 1/9 patients with IT injection, and sustained increases in inflammatory cytokines were observed following dosing, particularly with higher intravenous dose levels. Conclusions: This phase 1a study provided initial proof-of-mechanism for NG-350A, with strong evidence of tumor delivery, viral replication and transgene expression—particularly after intravenous dosing. The lack of transgene-related or off-target viral toxicity was consistent with the highly selective delivery and replication of NG-350A, even after systemic delivery. The efficacy of intravenous-dosed NG-350A will now be evaluated in combination with pembrolizumab (NCT05165433), as well as with chemoradiotherapy (NCT06459869). Trial registration number: NCT05165433, NCT06459869.

The pioneers of tumor immunology and cancer immunotherapy, including the late William B. Coley and Lloyd J. Old, have championed the potential for immunotherapy for over a century. Finally, advances in our understanding of the fundamentals of tumor immunology are translating into clinical success, with recent US Food and Drug Administration approval of several immunotherapies that improve clinical outcomes across prostate cancer, metastatic melanoma, non-small cell lung cancer and lymphocytic leukemia. In tandem with these clinical successes, new technologies such as high-throughput DNA/RNA sequencing, genetic engineering, and streamlined ex vivo cell culturing have paved the way for the next generation of immunotherapies and provided new tools for investigating potential biomarkers of response to existing therapies. During the November 2014 Annual Meeting of the Society of the Immunotherapy of Cancer, leaders in tumor immunology and cancer immunotherapy convened at the second annual SITC Primer to review both current knowledge and future directions in the field. Here, we will review the key discussions across a variety of topics, including innate immunity, adaptive immunity, dendritic cells, adoptive T cell therapy, anti-tumor antibodies, cancer vaccines, immune checkpoint blockade, challenges to immunotherapy, monitoring immune responses, and immunotherapy clinical trial design.