Preclinical investigation of anti-tumor efficacy of allogeneic natural killer cells combined with cetuximab for head and neck squamous cell carcinoma.

Head and neck squamous cell carcinoma (HNSCC) presents a significant therapeutic challenge because of the limited effectiveness of current treatments including immunotherapy and chemotherapy. This study investigated the potential of a novel combination therapy using allogeneic natural killer (NK) cells and cetuximab, an anti-epidermal growth factor receptor monoclonal antibody, to enhance anti-tumor efficacy in HNSCC. Allogeneic NK cells were tested against HNSCC cells in vitro and NOG (NOD/Shi-scid/IL-2Rγ null) xenograft mouse models for cytotoxicity. In vitro assays demonstrated enhanced cytotoxicity against HNSCC cells when NK cells were combined with cetuximab, a phenomenon attributed to antibody-dependent cellular cytotoxicity. In vivo, the combination therapy exhibited a significant anti-tumor effect compared to either monotherapy, with high NK cell infiltration and cytotoxic activity in the tumor microenvironment. Tumor infiltration by NK cells was confirmed using flow cytometry and immunohistochemistry, highlighting the increased presence of NK cells (CD3(-) CD56(+)). These findings suggest that combination allogeneic NK cells and cetuximab could be a potential therapeutic modality for HNSCC and provide a foundation for future clinical trials to improve patient outcomes.