Abstract B026: SIWA318H, a novel advanced glycation end product (AGE) specific antibody, targets cancer and senescent cells in the tumor microenvironment and exhibits potent antitumor activity in a humanized mouse model for pancreatic cancer. [R

Abstract

Abstract The aging-related and cancer cell derived oxidatively stressed tumor microenvironment drives cell senescence. Senescent cells (SCs), in turn, promote immune suppression, tumor progression, and metastasis. Hence, targeting SCs presents an attractive approach for cancer therapy. SIWA318H is a monoclonal antibody that selectively targets an advanced glycation end product biomarker on the surface of dysfunctional cells exhibiting both (a) aerobic glycolysis and (b) oxidative stress. The SIWA318H biomarker is associated with cancer cells, SCs, oxidatively damaged cells, and infected cells. SIWA318H has been shown to bind to an ADCC inducing human IgG FcγR3 receptor as a mechanism of action. SIWA318H exhibits strong binding to pancreatic cancer patient derived xenograft tumors as demonstrated by immunohistochemistry. In an in vivo study using a humanized mouse xenograft model for pancreatic cancer, we showed that treatment with SIWA318H (both high and low dose groups) statistically significantly reduced tumor growth compared to the isotype antibody control group (P < 0.0001). In addition, there was a significantly higher number of mice had complete remission in the treated groups compared to the isotype control group: 37.5% in high dose group (P = 0.0325) and 43.8% in low dose group (P = 0.0143). Moreover, mice treated with 318H had a median overall survival of > 45 days compared to 26 days for the isotype control mice. There was no difference in animal body weight between the SIWA318H-treated mice and the isotype control mice. Immunohistochemical analysis of tumor tissues taken from the in vivo study showed that SIWA318H treatment significantly reduced (a) tumor fibrosis as measured by the area of αSMA+ staining and (b) the number of senescent cells in the tumor stroma as measured by the number of p16INK4a positive cells in αSMA+ areas. In summary, our results demonstrate that SIWA318H is a novel senolytic antibody that exhibits potent preclinical antitumor activity against pancreatic cancer. SWA318H is currently under development for a first in human clinical trial. Citation Format: Gabriela Rossi, Lewis Gruber, Misty Gruber, Haiyong Han. SIWA318H, a novel advanced glycation end product (AGE) specific antibody, targets cancer and senescent cells in the tumor microenvironment and exhibits potent antitumor activity in a humanized mouse model for pancreatic cancer. [R] [abstract]. In: Proceedings of the AACR Special Conference: Aging and Cancer; 2022 Nov 17-20; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2022;83(2 Suppl_1):Abstract nr B026.