{
  "abstract": "Background TK-6302 is a novel TCR-T cell therapy targeting PRAME, designed with best-in-class potential. It incorporates a high-affinity TCR, a costimulatory CD8 co-receptor engaging CD4 T cells and providing co-stimulation upon TCR engagement, and a FAS switch receptor (SwR) boosting engraftment and fitness. TK-6302 cells are manufactured with a non-viral genome editing process. Here we present the preclinical safety and efficacy package supporting advancement of TK-6302 into a First-In-Human trial.Methods Off-target TCR recognition motifs were analyzed using a panel of peptide variants (X-scan). Potential recognition of healthy tissues was assessed by co-culture of TK-6302 with commercially available primary tissue-derived cells and iPSC-differentiated cell types. Alloreactivity was tested by IFN-γ quantification upon co-culture with HLA-mismatched lymphoblastoid cell lines (LCL). Functional activity was assessed by cytokine secretion (ELISA and LEGENDplex) and cytotoxicity using IncuCyte real time imaging. Antigen-independent growth was assessed by cell count. All preclinical studies were conducted with TK-6302 produced from at-scale manufacturing runs with healthy donor material representing the intended clinical product.Results Potential off-target recognition motifs of TK-6302 TCR were identified by X-scan and subsequently derisked using co-cultures with peptide-loaded cells and cell lines overexpressing the corresponding peptides and/or proteins, confirming the TCR’s specificity. Moreover, co-culture of TK-6302 with 20 primary tissue-derived or iPSC-derived cell types demonstrated a safe recognition profile with expected recognition patterns. Alloreactivity was cleared with > 97% HLA coverage. The FAS-SwR expression protected TK-6302 from FAS-ligand induced cell death, but did not result in aberrant activation of TK-6302 in the absence of antigen. Importantly, TK-6302 showed robust anti-tumor activity against a variety of cancer cell lines derived from various indications, as demonstrated using cytokine secretion, cytotoxicity upon long-term and repeated stimulation, and upon co-culture with multi-cellular tumor spheroids mirroring the plethora of challenges raised by solid tumors.Conclusions TK-6302 demonstrates a favorable preclinical safety profile and robust functional activity supporting its advancement to clinical evaluation in multiple PRAME-expressing cancer indications.",
  "authors": [
    {
      "affiliations": [
        "T-knife GmbH, Berlin, Germany"
      ],
      "name": "Gianna Triller"
    },
    {
      "affiliations": [
        "T-knife GmbH, Berlin, Germany"
      ],
      "name": "Natallia Salei"
    },
    {
      "affiliations": [
        "T-knife GmbH, Berlin, Germany"
      ],
      "name": "Lejla Stettnisch"
    },
    {
      "affiliations": [
        "T-knife GmbH, Berlin, Germany"
      ],
      "name": "Claudia Selck"
    },
    {
      "affiliations": [
        "T-knife GmbH, Berlin, Germany"
      ],
      "name": "Mira Heichenko"
    },
    {
      "affiliations": [
        "T-knife GmbH, Berlin, Germany"
      ],
      "name": "Vijay Srinivasan"
    },
    {
      "affiliations": [
        "T-knife GmbH, Berlin, Germany"
      ],
      "name": "Kateryna Herasymenko"
    },
    {
      "affiliations": [
        "T-knife GmbH, Berlin, Germany"
      ],
      "name": "Alexei Leliavski"
    },
    {
      "affiliations": [
        "T-knife GmbH, Berlin, Germany"
      ],
      "name": "Mohamad Toutounji"
    },
    {
      "affiliations": [
        "T-knife Therapeutics, Inc, San Francisco, CA, USA"
      ],
      "name": "Panagiota A Sotiropoulou"
    },
    {
      "affiliations": [
        "T-knife GmbH, Berlin, Germany"
      ],
      "name": "Marion Jurk"
    }
  ],
  "title": "329 TK-6302, a supercharged PRAME TCR-T cell therapy containing a high affinity TCR, a costimulatory CD8 coreceptor and a FAS-based switch receptor, demonstrates preclinical safety and efficacy",
  "uid": "7f8de928-2fbf-5d79-b0e0-f26a7a51fecf"
}