Project description:Poly I:C is a powerful immune adjuvant as a result of its agonist activities on TLR-3, MDA5 and RIG-I. Intratumoral administration is conceivably safer than systemic delivery and allows concentrate proinflammatory adjuvanticity in the tumor microenvironment and tumor-draining lymphoid tissue. BO-112 is a nanoplexed formulation of Poly I:C complexed with polyethylenimine that causes tumor cell apoptosis showing immunogenic cell death features and that upon intratumoral release results in more prominent tumor infiltration by T lymphocytes. Intratumoral treatment of subcutaneous tumors derived from MC38, 4T1 and B16F10 with BO-112 leads to remarkable local disease control mediated by CD8+ T lymphocytes, as concluded from selective depletion experiments. Some degree of control of non-injected tumor lesions upon BO-112 intratumoral treatment was found in mice bearing bilateral B16OVA melanomas, that was enhanced when co-treated with systemic anti-CD137 and anti-PD-L1 immunomodulatory mAbs. More abundant CD8+ T lymphocytes were found in tumor-draining lymph nodes and in the tumor microenvironment following intratumoral treatment with BO-112. Enhanced numbers of tumor-specific CTLs recognizing melanosomal antigens and ovalbumin were readily detected among them. Genome-wide transcriptome analyses of injected tumor lesions were consistent with a marked upregulation of the type-I interferon pathway. Intratumorally delivered BO-112 is being tested in cancer patients (NCT02828098) and our results in mice suggest prominent anti-tumor local control through its proimmune effects. Intratumoral administration of BO-112, a nanoplexed form of PolyI:C, triggers an efficacious antitumor response in different tumor models as a consequence of proimmflamatory activity and its direct effects in tumor cells. BO-112 local administration induces direct tumor cell death by apoptosis, showing signs of immunogenic cell death, and a strong release of IFNα/β and other proinflammatory mediators. As a result, a tumor-specific CD8+ immune response is mounted or augmented to the point of controlling tumor progression both in the locally injected lesion and to some extent on distantly implanted tumor nodules

Project description:By their selective infection or replication into tumors, oncolytic viruses trigger profound modifications of tumor immune microenvironment with a massive infiltration and activation of T cells. This tumor warming up can be further amplified by the local delivery of powerful immunomodulatory molecules encoded into virus’ genome. Those properties are particularly of interest for tumor poorly infiltrated or infiltrated with anergic T cells to reverse patient’s unresponsiveness to immune checkpoint inhibitors (ICI). TG6050 is a new oncolytic vaccinia virus encoding single-chain human Interleukin-12 (hIL-12) and full length anti-cytotoxic T-lymphocyte-associated antigen-4 (@CTLA-4) monoclonal antibody. Replication, oncolysis, selectivity, transgenes expression and functionality of TG6050 were characterized in vitro. Virus and IL-12 pharmacokinetics, antitumoral activities (alone or combined with ICI), and mechanism of action (MOA) were investigated in “hot” (highly infiltrated) and “cold” (poorly infiltrated) syngeneic murine tumor models. MOA was deciphered by monitoring both systemic and tumor immune responses, and tumor transcriptome analyses. Finally, TG6050 safety after repeated intravenous administrations was evaluated in cynomolgus monkeys and special attention was paid to the level of circulating IL-12 potentially associated with toxic effects. In vitro or in vivo replication of TG6050 in tumor cells allows local expression of functional IL-12 and @CTLA-4. The expression of transgenes, together with the virus replication, translated into an antitumoral activity in both “cold and “hot” tumor murine models that was further amplified by combination with ICI. Analysis of tumor microenvironment (TME) after TG6050 treatment showed an increase of interferon gamma, CD8+ T cells, M1/M2 macrophages ratio and a drastic decrease of regulatory T cells. Those local modifications were observed together with an enhanced systemic and specific antitumor adaptive immune response. In toxicology studies, the virus did not produce any observable adverse effects in cynomolgus monkeys. Conclusions: TG6050 allows the delivery of functional IL-12 and @CTLA-4 into tumor resulting in an excellent antitumor activity along with a shift towards an inflamed TME, and a boost of the systemic antitumor T-cells. Toxicological studies in macaques demonstrated the safety of TG6050. Together these results paved the way for clinical evaluation of TG6050 in metastatic non-small cell lung cancer (NCT05788926).

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The role of residue chirality of polypeptide hydrogels in regulating local immune microenvironment for anti-tumor immune responses

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