InVivoSIM anti-human PD-1 (Nivolumab Biosimilar)

Adoptive cell therapy based on chimeric antigen receptor (CAR)-engineered T-cells has proven to be lifesaving for many cancer patients. However, its therapeutic efficacy has so far been restricted to only a few malignancies, with solid tumors proving to be especially recalcitrant to efficient therapy. Poor intra-tumor infiltration by T cells and T cell dysfunction due to a desmoplastic, immunosuppressive microenvironment are key barriers for CAR T-cell success against solid tumors. Cancer-associated fibroblasts (CAFs) are critical components of the tumor stroma, evolving specifically within the tumor microenvironment (TME) in response to tumor cell cues. The CAF secretome is a significant contributor to the extracellular matrix and a plethora of cytokines and growth factors that induce immune suppression. Together they form a physical and chemical barrier which induces a T cell-excluding 'cold' TME. CAF depletion in stroma rich solid tumors can thus provide an opportunity to convert immune evasive tumors susceptible to tumor-antigen CAR T-cell cytotoxicity. Using our TALEN-based gene editing platform we engineered non-alloreactive, immune evasive CAR T-cells (termed UCAR T-cells) targeting the unique CAF marker Fibroblast Activation Protein, alpha (FAP). In an orthotopic mouse model of triple-negative breast cancer (TNBC) composed of patient derived-CAFs and tumor cells, we demonstrate the efficacy of our engineered FAP UCAR T-cells in CAF depletion, reduction of desmoplasia and successful tumor infiltration. Furthermore, while previously resistant, pre-treatment with FAP UCAR T-cells now sensitized these tumors to Mesothelin (Meso) UCAR T-cell infiltration and anti-tumor cytotoxicity. Combination therapy of FAP UCAR, Meso UCAR T cells and the checkpoint inhibitor anti-PD-1 significantly reduced tumor burden and prolonged mice survival. Our study thus proposes a novel treatment paradigm for successful CAR T-cell immunotherapy against stroma-rich solid tumors.

YIV-906 is a systems biology botanical cancer drug, inspired by a traditional Chinese herbal formulation. Results from eight Phase I/II to II clinical studies demonstrated the potential of YIV-906 to prolong survival and improve the quality of life of cancer patients. As an immunomodulator in the tumor microenvironment, YIV-906 can turn cold tumors hot and potentiate anti-tumor activity for different classes of anticancer agents; and as a cytoprotector in the GI, YIV-906 can reduce non-hematological side effects and speed up damaged tissue recovery. YIV-906 enhanced anti-PD1 action against hepatoma in mice by stimulating both innate and adaptive immunity. In a Jurkat cell-staphylococcal superantigen E (SEE)-Raji cell culture model, YIV-906 promoted T cell activation with upregulation of CD69 by enhancing NFAT activity, with or without PD1-PD-L1 interaction. YIV-906 could trigger the phosphorylation of TCR downstream signaling cascades without the involvement of TCR. YIV-906 could inhibit SHP1 and SHP2 activities, which dephosphorylates TCR downstream proteins due to the PD1-PD-L1 interaction. Therefore, YIV-906 could enhance anti-PD1 action to rescue the depressed NFAT activity of Jurkat cells due to the PD1-PD-L1 interaction. In addition, YIV-906 enhanced the NFAT activity and killing capability of Jurkat cells expressing chimeric antigen receptor (CAR-CD19^-CD3z) toward CD19 expressing cells, such as Raji cells, with or without PD1-PD-L1 overexpression. Ingredient herb S (Scutellaria baicalensis Georgi) of YIV-906 and some S compounds were found to play key roles in these activities. In conclusion, YIV-906 modulates adaptive immunity by activating T effector cells mainly through its action on SHP1/2. YIV-906 could also facilitate immune checkpoint blockade therapy or CAR-T cell therapy for cancer treatment.

Anti-PD-1 therapy targets intratumoral CD8+ T cells to promote clinical responses in cancer patients. Recent evidence suggests an additional activity in the periphery, but the underlying mechanism is unclear. Here, we show that anti-PD-1 mAb enhances CD8+ T cell responses in tumor-draining lymph nodes by stimulating cytokine production in follicular helper T cells (Tfh). In two different models, anti-PD-1 mAb increased the activation and proliferation of tumor-specific T cells in lymph nodes. Surprisingly, anti-PD-1 mAb did not primarily target CD8+ T cells but instead stimulated IL-4 production by Tfh cells, the major population bound by anti-PD-1 mAb. Blocking IL-4 or inhibiting the Tfh master transcription factor BCL6 abrogated anti-PD-1 mAb activity in lymph nodes while injection of IL-4 complexes was sufficient to recapitulate anti-PD-1 mAb activity. A similar mechanism was observed in a vaccine model. Finally, nivolumab also boosted human Tfh cells in humanized mice. We propose that Tfh cells and IL-4 play a key role in the peripheral activity of anti-PD-1 mAb.

Hepatitis B virus (HBV) infection generally elicits weak type-I interferon (IFN) immune response in hepatocytes, covering the regulatory effect of IFN-stimulated genes. In this study, low level of IFN-stimulated gene 12a (ISG12a) predicted malignant transformation and poor prognosis of HBV-associated hepatocellular carcinoma (HCC), whereas high level of ISG12a indicated active NK cell phenotypes. ISG12a interacts with TRIM21 to inhibit the phosphorylation activation of protein kinase B (PKB, also known as AKT) and β-catenin, suppressing PD-L1 expression to block PD-1/PD-L1 signaling, thereby enhancing the anticancer effect of NK cells. The suppression of PD-1-deficient NK-92 cells on HBV-associated tumors was independent of ISG12a expression, whereas the anticancer effect of PD-1-expressed NK-92 cells on HBV-associated tumors was enhanced by ISG12a and treatments of atezolizumab and nivolumab. Thus, tumor intrinsic ISG12a promotes the anticancer effect of NK cells by regulating PD-1/PD-L1 signaling, presenting the significant role of innate immunity in defending against HBV-associated HCC.