Abstract 4260: 3D colorectal cancer organoids as preclinical models for assessment of activity of RAF inhibitor BGB-283

Abstract

Abstract Tumor organoids are three-dimensional (3D) cultures of cancer cells. They can be derived from the tumor cell lines, patient-derived xenografts and tumor tissues from cancer patients, thereby providing an attractive in vitro assay to optimize anticancer treatment. Oncogenic B-RAF, which drives cell transformation and proliferation, has been detected in 5-15% of colorectal cancers (CRC). Despite the remarkable clinical activities achieved by vemurafenib in treating B-RAF V600E metastatic melanoma, their clinical efficacy in B-RAF V600E CRC is far less impressive. BGB-283, currently under clinical development for RAF and RAS mutated solid tumors, is a novel inhibitor of the RAF dimer with inhibitory activities against RAF family kinases. In this study, we evaluated the anti-proliferative effect of BGB-283 and compared it to BRAF inhibitor vemurafenib in CRC patient tumor derived organoids models. BGB-283 exhibited therapeutic potentials in tumors with mutations in the MAPK pathway. Herein, we reported the establishment of tumor organoid models from 19 CRC patients’ tumor tissues with a success rate of 83%. Organoids maintained many characteristics of their original tumors based on their histology. Our studies using primary CRC tumor organoids showed that in contrast to vemurafenib, which only inhibited B-RAF V600E CRC tumors, BGB-283 had inhibition effect on both B-RAF V600E and KRAS mutated tumors. These findings support BGB-283 as a promising clinical stage antitumor agent in treating CRC harboring B-RAF V600E and KRAS mutations. In addition, we showed that patient-derived organoids can be a valuable tool to test drug sensitivity in a personalized treatment and help to fill the gap between tumor genetics and patient trials. Citation Format: Xiaoran Wu, Chunyan Fu, Xi Yuan, Lianhai Zhang, Xiaohong Wang, Jiafu Ji, Lusong Luo. 3D colorectal cancer organoids as preclinical models for assessment of activity of RAF inhibitor BGB-283. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4260.