Abstract C073: CRO-67 is a novel therapeutic for pancreatic cancer: Implications for tumor and stromal reprogramming

Abstract

Abstract Background: Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignancies and new therapeutic strategies are urgently required. A key drug delivery barrier and promoter of tumor progression is the fibrotic and heterogeneous microenvironment of PDAC which is mainly orchestrated by stromal cancer-associated fibroblasts (CAFs). Thus, any novel therapeutic strategy should not only target PDAC cells but should also aim to inhibit the pro-tumor properties of the PDAC stroma. However, to accurately evaluate the clinical potential of novel PDAC therapeutics, preclinical models are required that closely mimic the heterogeneity and multicellular architecture of human disease. Aim: We aimed to investigate the therapeutic potential of novel functionalized benzopyrans (CRO-05 & CRO-67) in a patient-derived PDAC tumor explant model. Methods: We collected PDAC tumor samples from patients undergoing resection of their primary tumor. We cultured whole tumor explants (1-2mm diameter) on gelatin sponges. This model accurately maintains the multicellular tumor and stromal architecture of human PDAC [Kokkinos et al, Scientific Reports, 11,1941 (2021)]. Tumor explants were treated every 3 days with the racemic compound CRO-05 or its active enantiomer CRO-67 and explants were fixed in paraformaldehyde at day-12. Therapeutic response was assessed by immunohistochemistry for markers of tumor cells (cytokeratin), CAFs (α-Smooth Muscle Actin), cell-proliferation (Bromodeoxyuridine), and cell-death (TUNEL). Results: Treatment of human PDAC explants with CRO-05 resulted in reduced tumor cell frequency in 3/4 patients and in 4/4 patients, reduced CAF frequency, decreased cell-proliferation, and increased cell-death relative to controls. CRO-67 treatment in explants from 4/5 patients led to reduced tumor cell frequency, and in 5/5 patients, reduced CAF frequency, decreased cell-proliferation, and increased cell-death relative to controls. Conclusions: This work identifies the functionalized benzopyrans CRO-05 and CRO-67 as novel dual-cell therapeutics that potently inhibit both PDAC tumor cells and their surrounding CAFs and provides support for their clinical development as novel PDAC therapeutics. Citation Format: John Kokkinos, George Sharbeen, Koroush S. Haghighi, Janet Youkhana, Aparna Raina, Omali Pitiyarachchi, Quach Truong, Daniel Wenholz, Olivier Laczka, Naresh Kumar, David Goldstein, Phoebe A. Phillips. CRO-67 is a novel therapeutic for pancreatic cancer: Implications for tumor and stromal reprogramming [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer; 2022 Sep 13-16; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2022;82(22 Suppl):Abstract nr C073.