{
  "abstract": "Background BNT327 (PM8002) and BNT314 (GEN1059/DuoBody ®-EpCAMx4-1BB) are investigational bispecific antibody (bsAb) immunomodulators. BNT327 combines blockade of the PD-1/PD-L1 checkpoint with VEGF-A neutralization, thereby reducing immune suppression and promoting vascular normalization, immune-cell activation and tumor infiltration. BNT314 is designed to boost antitumor immune responses through EpCAM-dependent activation of the co-stimulatory receptor 4-1BB expressed on activated T cells. Previous studies demonstrated that combining BNT314 with PD-1/PD-L1 blockade further potentiates its effects on T-cell function in vitro and antitumor activity in vivo. Here we investigated the potential of combining BNT327 with BNT314 to promote antitumor immunity in preclinical studies.Methods Co-cultures of CD8 + T cells purified from human peripheral blood mononuclear cells with EpCAM-transduced MDA-MB-231 tumor cells were used to study T-cell cytotoxic activity in vitro. In vivo, Fc-silenced bsAbs targeting mouse PD-L1 and mouse VEGF-A (mPD-L1xmVEGF-A) or human EpCAM and mouse 4-1BB (hEpCAMxm4-1BB) were tested in human EpCAM-transgenic mice bearing human EpCAM-expressing MC38 (MC38-hEpCAM) colorectal or B16F10 (B16F10-hEpCAM) melanoma tumors. Tumor growth and progression-free survival (PFS, defined as time until tumor volume reaches ≥500 mm3) were determined.Results Combining BNT327 with BNT314 enhanced expression of granzyme B and CD107a by CD8 + T cells, and significantly increased T-cell mediated killing of EpCAM+ tumor cells expressing cognate antigen in vitro, compared to each single agent. In this assay, PD-L1 blockade activity of BNT327 was comparable to atezolizumab both as a single treatment and in combination with BNT314. In vivo, combining mPD-L1xmVEGF-A with hEpCAMxm4-1BB delayed outgrowth of subcutaneous MC38-hEpCAM tumors and prolonged mouse PFS compared to both monotherapies. Combination treatment also mediated immunomodulation that was more pronounced compared to single-agent treatments, including enhanced frequencies of activated or tumor-targeting CD8+ T cells, and a shift towards an effector/memory CD8+ T-cell phenotype in the peripheral blood. Moreover, in mice bearing subcutaneous B16F10-hEpCAM tumors, the combination of mPD-L1xmVEGF-A and hEpCAMxm4-1BB enhanced antitumor activity and prolonged PFS beyond the single-agent effect of mPD-L1xmVEGF-A, whereas hEpCAMxm4-1BB alone had no effect in this model.Conclusions Combining a PD-L1xVEGF-A bsAb with an EpCAMx4-1BB bsAb potentiates single-agent effects on T-cell cytotoxic activity in vitro and enhances antitumor activity in vivo in a colorectal cancer model, and in a poorly immunogenic melanoma model that is unresponsive to hEpCAMxm4-1BB bsAb alone. Building on these data, a clinical trial is being initiated to investigate the safety and preliminary efficacy of BNT327 in combination with BNT314 and chemotherapy in patients with metastatic microsatellite-stable/proficient mismatch repair (MSS/pMMR) colorectal cancer.Acknowledgements The authors would like to thank Sissy Witt of BioNTech for her technical expertise and support.",
  "authors": [
    {
      "affiliations": [
        "BioNTech SE, Mainz, Germany"
      ],
      "name": "Andrea Imle"
    },
    {
      "affiliations": [
        "BioNTech SE, Mainz, Germany"
      ],
      "name": "Lena Wiedmann"
    },
    {
      "affiliations": [
        "BioNTech SE, Mainz, Germany"
      ],
      "name": "Marilena Wischnewski"
    },
    {
      "affiliations": [
        "BioNTech SE, Mainz, Germany"
      ],
      "name": "Aras Toker"
    },
    {
      "affiliations": [
        "BioNTech SE, Mainz, Germany"
      ],
      "name": "Ann-Kathrin Wallisch"
    },
    {
      "affiliations": [
        "BioNTech SE, Mainz, Germany"
      ],
      "name": "Selina Klein"
    },
    {
      "affiliations": [
        "Biotheus Inc., Zhuhai, Guangdong Province, China"
      ],
      "name": "Xiaoniu Miao"
    },
    {
      "affiliations": [
        "Biotheus Inc., Zhuhai, Guangdong Province, China"
      ],
      "name": "Yi Luo"
    },
    {
      "affiliations": [
        "Biotheus Inc., Zhuhai, Guangdong Province, China"
      ],
      "name": "Andy Tsun"
    },
    {
      "affiliations": [
        "BioNTech SE, Mainz, Germany"
      ],
      "name": "Ilhan Celik"
    },
    {
      "affiliations": [
        "BioNTech SE, Mainz, Germany"
      ],
      "name": "Özlem Türeci"
    },
    {
      "affiliations": [
        "BioNTech SE, Mainz, Germany"
      ],
      "name": "Ugur Sahin"
    }
  ],
  "title": "652 Combining the bispecific antibodies BNT327 (PD-L1xVEGF-A) and BNT314 (EpCAMx4–1BB) enhances T-cell mediated cytotoxicity and antitumor activity in preclinical studies",
  "uid": "dc4d3553-e205-5acd-aa56-75d589bbd6f2"
}