Strategies for Cancer Immunotherapy Development: Preclinical Studies

Division Of Basic Sciences - Nci

Investigators

Linked publications, trials & patents

Abstract

Recent accomplishments include the following: [] THE USE OF TUMOUR-TARGETED INTERLEUKIN-12 AND ENTINOSTAT COMBINATION THERAPY TO IMPROVE CANCER SURVIVAL BY REPROGRAMMING THE TUMOUR IMMUNE CELL LANDSCAPE. Poorly inflamed carcinomas do not respond well to immune checkpoint blockade. Converting the tumour microenvironment into a functionally inflamed immune hub would extend the clinical benefit of immune therapy to a larger proportion of cancer patients. We have shown, by using comprehensive single-cell transcriptome, proteome, and immune cell analysis, that Entinostat, a class I histone deacetylase inhibitor, facilitates accumulation of the necrosis-targeted recombinant murine immune-cytokine, NHS-rmIL12, in experimental mouse colon carcinomas and poorly immunogenic breast tumours. This combination therapy reprograms the tumour innate and adaptive immune milieu to an inflamed landscape, where the concerted action of highly functional CD8+ T cells and activated neutrophils drive macrophage M1-like polarization, leading to complete tumour eradication in 41.7%-100% of cases. Biomarker signature of favourable overall survival in multiple human tumor types shows close resemblance to the immune pattern generated by Entinostat/NHS-rmIL12 combination therapy. Collectively, these findings provide a rationale for combining NHS-IL12 with Entinostat in the clinical setting. [] TUMOR-TARGETED INTERLEUKIN-12 SYNERGIZES WITH ENTINOSTAT TO OVERCOME PD-1/PD-L1 BLOCKADE-RESISTANT TUMORS HARBORING MHC-I AND APM DEFICIENCIES. Immune checkpoint blockade (ICB) has achieved unprecedented success in treating multiple cancer types. However, clinical benefit remains modest for most patients with solid malignancies due to primary or acquired resistance. Tumor-intrinsic loss of major histocompatibility complex class I (MHC-I) and aberrations in antigen processing machinery (APM) and interferon gamma (IFN-gamma) pathways have been shown to play an important role in ICB resistance. While a plethora of combination treatments are being investigated to overcome ICB resistance, there are few identified preclinical models of solid tumors harboring these deficiencies to explore therapeutic interventions that can bypass ICB resistance. Here, we investigated the combination of the epigenetic modulator entinostat and the tumor-targeted immunocytokine NHS-IL12 in three different murine tumor models resistant to aPD-1/aPD-L1 (anti-programmed cell death protein 1/anti-programmed death ligand 1) and harboring MHC-I, APM, and IFN-gamma response deficiencies and differing tumor mutational burden (TMB). Entinostat and NHS-IL12 were administered to mice bearing TC-1/a9 (lung, HPV16 E6/E7+), CMT.64 lung, or RVP3 sarcoma tumors. Antitumor efficacy and survival were monitored. Comprehensive tumor microenvironment (TME) and spleen analysis of immune cells, cytokines, and chemokines was performed. Additionally, whole transcriptomic analysis was carried out on TC-1/a9 tumors. Cancer Genome Atlas (TCGA) datasets were analyzed for translational relevance. We have demonstrated that the combination of entinostat and NHS-IL12 therapy elicits potent antitumor activity and survival benefit through prolonged activation and tumor infiltration of cytotoxic CD8+ T cells, across aPD-1/aPD-L1 refractory tumors irrespective of TMB, including in the IFN-? signaling-impaired RVP3 tumor model. The combination therapy promoted M1-like macrophages and activated antigen-presenting cells while decreasing M2-like macrophages and regulatory T cells in a tumor-dependent manner. This was associated with increased levels of IFN-gamma, IL-12, chemokine (C-X-C motif) ligand 9 (CXCL9), and CXCL13 in the TME. Further, the combination therapy synergized to promote MHC-I and APM upregulation, and enrichment of JAK/STAT (janus kinase/signal transducers and activators of transcription), IFN-gamma-response and antigen processing-associated pathways. A biomarker signature of the mechanism involved in these studies is associated with patients' overall survival across multiple tumor types. Our findings provide a rationale for combining the tumor-targeting NHS-IL12 with the histone deacetylase inhibitor entinostat in the clinical setting for patients unresponsive to aPD-1/aPD-L1 and/or with innate deficiencies in tumor MHC-I, APM expression, and IFN-gamma signaling. [] CHARACTERIZATION OF RECOMBINANT GORILLA ADENOVIRUS HPV THERAPEUTIC VACCINE PRGN-2009. 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-beta2m-/- 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. Phase I and II clinical trials employing PRGN-2009 both as monotherapy and in combination therapies are ongoing in patients with HPV malignancies. Several other studies are also ongoing; these involve: [] Studies of bintrafusp alfa, a novel bifunctional anti-PD-L1/TGFbetaRII agent. [] Remodeling the tumor microenvironment via blockade of LAIR-1 and TGF-beta signaling enables PD-L1-mediated tumor eradication. [] Combination therapies for HPV-associated malignancies using a peptide-based HPV targeting vaccine.