Abstract 2858: Development of a first-in-class humanized antibody targeting CXCL1 in bladder cancer

Abstract Introduction and Objectives: Chemokine (C-X-C motif) ligand 1 (CXCL1) plays a crucial role in tumor initiation, promotion, and progression in bladder cancer (BCa) development. Previously, we reported on a monoclonal murine antibody (HL2401) towards CXCL1 which was capable of inhibiting growth in both in vitro and in vivo models. Herein, we have developed a first-in-class humanized monoclonal antibody neutralizing CXCL1 (NTC-001). This study is final step in pre-clinical stage. In this study, we aimed to evaluate efficacy and safety of the antibody to move into phase 1 clinical trials in near future. Methods: We humanized mouse anti-human CXCL1 antibody resulting in NTC-001, and then tested for the following: molecular weight and pH, specificity, binding affinity to ligand and to albumin, ability to inhibit in vitro angiogenesis, ability to inhibit cellular proliferation alone or with chemotherapy, and pharmacokinetics and pharmacodynamics. Results: NTC-001 had a molecular weight of 150kD, and was an acidic antibody (pH5.1). NTC-001 specifically bound human CXCL1 in both WB and ELISA. NTC-001 was bound to albumin and had minimal hepatic metabolism. NTC-001 significantly inhibited tube formation in HUVEC, and more efficiently with the formulation. NTC-001 significantly inhibited T24 cell proliferation (p<0.001). Inhibitory effect of NTC-001 on cell proliferation was correlated with the levels of CXCL1 expression in BCa cell lines. Compared to CXCL1 expression-low group (RT112 and UMUC-14), CXCL1 expression-high group (T24, 5637, 253J, 253J-BV) tended to show low IC50. Synergistic combination efficacy was observed in NTC-001 in combination with gemcitabine (combination index<1) though not with cisplatin. PK study demonstrated a half-life of 324 hours and 18 hours in CD-1 and NSG-SGM3, respectively. Conclusions: NTC-001 is a first in class humanized neutralizing monoclonal antibody towards CXCL1, and could be a promising therapeutic agent in BCa. We are going to proceed to complete our investigational new drug enabling studies in both small and large animals. Citation Format: Kaoru Murakami, Yuka Sasaki, Hideki Furuya, Charles Rosser. Development of a first-in-class humanized antibody targeting CXCL1 in bladder cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2858.