Thursday, December 26, 2024
12/26/2024
PROJECT SUMMARY Despite substantial improvements in therapeutic strategies, generating robust anti-tumor immune responses in human cancers with a lower somatic mutation burden remains a substantial challenge. Recent data indicate that a critical player in this process, dendritic cells (DCs), fail to effectively elicit efficient and durable T cell responses unless they have entered a unique state of hyperactivation. In this setting, DCs exhibit enhanced migration to local lymph nodes (LNs) and sustained secretion of IL-1β, a cytokine critical for memory T cell formation. In mouse tumor models, vaccination with whole tumor lysate plus an adjuvant consisting of the TLR 7/8 agonist R848 (resiquimod) in combination with a unique isolated lysophosphatidylcholine (22:0 Lyso PC) promotes DC hyperactivation, expansion of antigen specific CD8+ T cells, and robust rejection of tumors. While these findings are encouraging and suggest that identification of specific neoantigens is not necessary to prime and expand a pool of cytotoxic T cells (CTLs), validation and optimization of this approach necessitates the use of a model system that more closely recapitulates human cancers with respect to immune landscape. As such, the purpose of this proposal is to use spontaneous canine cancer, specifically osteosarcoma (OS), as a bridging animal model to validate the utility of DC hyperactivation as a foundational element for generation of robust anti-tumor immunity. The central hypothesis to be tested in this application is that combining hyperactivation of DCs with WTL derived neoantigen will expand a diverse and tumor-specific population of CTLs capable of eliminating residual microscopic metastatic OS tumor cells in dogs following primary tumor removal (amputation). We further predict, that combining DC hyperactivation/WTL with a novel tumor microenvironment (TME) conditioning regimen consisting of toceranib/losartan/ladarixin will enhance the objective response rate in dogs that develop macroscopic lung metastasis. To accomplish this, we will conduct a prospective randomized clinical trial in dogs with OS combining amputation and standard of care carboplatin chemotherapy with adjuvant alone or adjuvant+WTL. Dogs that develop lung metastasis will then be treated with the TME conditioning regimen in combination with adjuvant+WTL. A biobank of tissue samples and blood will be collected from dogs enrolled in these trials including matched primary/metastatic tumors and associated LNs, whole blood, plasma, PBMCs, cell-free DNA, and samples from the vaccine draining LNs. These will be used to perform a set of complementary assays designed to characterize the immune microenvironment and tumor genome over the course of relapse/resistance, credential a novel neoantigen prediction pipeline, and evaluate antigen specific T cell responses. An outstanding team with complementary sets of expertise across clinical trials, translational oncology, comparative genomics, and immuno-oncology has been assembled to ensure stated milestones are achieved. This is bolstered by a dynamic collaboration with our industry partner, Corner Therapeutics, which is committed to supporting this work to facilitate optimization and successful translation into human patients.
HHS’ Tracking Accountability in Government Grants System (TAGGS) website provides access to detailed descriptions of grants, loans, aggregated direct payments and other types of financial assistance awarded by the HHS Operating Divisions (OPDIVs) and the Office of the Secretary Staff Divisions (STAFFDIVs).