{
  "abstract": "Background Triple-negative breast cancer (TNBC) is an aggressive subtype with limited treatment options and higher mortality than other breast cancer subtypes. Tumor hypoxia due to rapid proliferation of cancer cells impairs T cell infiltration and function in TNBC. Although reversing tumor hypoxia has shown promise in pre-clinical tumor models, existing oxygenation strategies remain limited for clinical translation. NanO 2 (NuvOx Pharma), a novel perfluorocarbon-based oxygen therapeutic composed of 2% w/v dodecafluoropentane, improves tissue oxygenation without receptor binding. It has been shown to reverse tumor hypoxia in preclinical models and in patients with Glioblastoma Multiforme. We hypothesized, that reversing hypoxia with NanO2 will change tumor microenvironment (TME) to enhance response to immunotherapy and chemotherapy.Methods We tested NanO 2 on hypoxia reversal, changes in TME in a syngeneic TNBC model (4T1 cells in BALB/c mice). Flow cytometry and IHC (CD4, CD8a, CD19, CD206, F4/80, PD-1) were used to characterize immune cell populations. In our first series of experiments we tested the effect of NanO2 with/without oxygen in 2 dosing regimens: single dose or five daily doses. Seventy mice received either saline or NanO2 intravenously, with air or O2 exposure for 17 days starting on day 5 post-tumor implantation. In the second series of experiments, we tested the effect of NanO2 in combination with immunotherapy (IT), chemotherapy (CTX, paclitaxel) or both IT and CTX. BALB/c mice were treated for three weeks starting on day 3 post-implantation with IV NanO2 (every 3 days), anti-PD-1 (200 µg IV every 5 days), Paclitaxel (2 µg/g IP every 3 days), or combinations. Due to unexpected mortality, only 26 mice reached the endpoint.Results Treatment with NanO 2 decreased hypoxic cells when combined with oxygen. In addition, it decreased PD-1 positive cells, increased CD8 cell infiltration (figure 1). Tumor associated macrophages (TAMs) were also increased. PD-1 expression decreased supporting that reversing hypoxia can enhance response to IT. In addition, in the second series of experiments we demonstrated that the TME changes by NanO2 +oxygen were enhanced by IT, CTX and combination IT+CTX (figure 2).Conclusions NanO 2 synergizes with immunotherapy and chemotherapy to remodel the TME to enhance anti-tumor immune responses in in vivo TNBC models.Acknowledgements This study was funded by DOD Grant to Pavani Chalasani (Award number:W81XWH2210640Ethics Approval Study was approved by IACUC at GWUC and DOD ACCUROAbstracts 5 Figure 1CD8 IHC resultsAbstracts 5 Figure 2Hypoxia cells by flow cytometry",
  "authors": [
    {
      "affiliations": [
        "The George Washington University, Washington, DC, USA"
      ],
      "name": "Aparna Nanduru"
    },
    {
      "affiliations": [
        "National Institutes of Health, Silver Spring, MD, USA"
      ],
      "name": "Peter Egwom"
    },
    {
      "affiliations": [
        "The George Washington University, Washington, DC, USA"
      ],
      "name": "Alexi Kiss"
    },
    {
      "affiliations": [
        "The George Washington University, Washington, DC, USA"
      ],
      "name": "Gregory Cresswell"
    },
    {
      "affiliations": [
        "NuvOx Therapeutics, Tucson, AZ, USA"
      ],
      "name": "Jennifer Johnson"
    },
    {
      "affiliations": [
        "NuvOx Therapeutics, Tucson, AZ, USA"
      ],
      "name": "Evie C Unger"
    },
    {
      "affiliations": [
        "The George Washington University, Washington, DC, USA"
      ],
      "name": "Pavani Chalasani"
    }
  ],
  "title": "5 Immunomodulation of tumor microenvironment in triple negative breast cancer by reversing hypoxia with NanO2, a novel oxygen delivery agent",
  "uid": "871e7270-c50f-5ef2-a6a7-4518f03bf6f4"
}