Gujar and Cui et al. evaluated N17350, a next-generation therapeutic elastase, and found that it selectively induced immunogenic cell death in cancer cells (based on their increased expression of histone H1.0 and H1.2 proteins), driving tumor regression and inducing systemic antitumor immunity across a wide range of preclinical models. N17350 remained effective with repeated dosing and in resistant cancers, and synergized with immunotherapies, positioning it as a strong candidate for first-in-human clinical evaluation.

ABSTRACT: Recent clinical studies highlight the effectiveness of combining cytotoxic agents with immunotherapies, emphasizing the need for next-generation treatments that integrate both therapeutic approaches. Here, we use 30 cancer cell lines, 15 tumor models, and 45 patient samples to develop N17350, a therapeutic elastase that targets the "neutrophil elastase pathway" to induce tumor regression and stimulate anti-tumor immunity. N17350 leverages linker histone H1.0 and H1.2, proteins elevated in many cancers, to trigger immunogenic cancer cell death while preserving immune cells. Intra-tumoral N17350 administration induces rapid, genotype-independent tumor regression, triggering CD8(+) T cell activation to promote durable responses and enable checkpoint inhibitor efficacy in refractory models. N17350 maintains potency with repeated dosing and across diverse treatment histories, including resistance to chemotherapies and checkpoint inhibitors. These findings support the advancement of N17350 to first-in-human clinical trials as a cytotoxic agent designed to stimulate anti-tumor immunity by selectively killing cancer cells.

Author Info: (1) Onchilles Pharma Inc., San Diego, CA, USA. (2) Onchilles Pharma Inc., San Diego, CA, USA. (3) Onchilles Pharma Inc., San Diego, CA, USA. (4) Onchilles Pharma Inc., San Diego, C A, USA. (5) South Coast Gynecologic Oncology Inc, San Diego, CA, USA. (6) Helen Diller Family Comprehensive Cancer Center, Department of Medicine, University of California, San Francisco, San Francisco, CA, USA. (7) The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust National Institute of Health Research Biomedical Research Centre, London, UK. (8) Onchilles Pharma Inc., San Diego, CA, USA. (9) Onchilles Pharma Inc., San Diego, CA, USA. Electronic address: lbecker@onchillespharma.com.