Expression data from 5 colorectal cancer patients neoadjuvantly treated with Imatinib (ImPACCT study)

Gene expression profiling of CMS4 colon cancer treated with Imatinib in the ImPACCT study. Fresh-frozen biopsies were taken during diagnostic colonoscopy for CMS4 identification. Five patients gave informed consent for two week of neoadjuvant Imatinib therapy prior to removal of the primary tumor. Fresh-frozen samples were taken from surgically resected colon cancer specimens. Overall design: Molecular subtyping of colon cancer has identified four Consensus Molecular Subtypes (CMS1-4). The mesenchymal subtype CMS4 is associated with poor prognosis and therapy resistance. In this proof-of-concept study, we assessed whether a rationally chosen drug (Imatinib) could mitigate the distinguishing molecular features of primary CMS4 colon cancer. In the ImPACCT trial, informed consent was obtained for molecular subtyping at initial diagnosis of colon cancer using a validated RT-qPCR CMS4-test on three colonoscopy biopsies per tumor (Phase-1, n=69 patients), and for neoadjuvant CMS4-targeting therapy with imatinib (Phase-2, n=5). Multiple biopsies were taken to account for intra-tumoral heterogeneity. Five patients consented to imatinib treatment prior to surgery. Three biopsies were taken from the surgical resection specimen per patient, yielding 15 pre- and 15 post-treatment samples from 5 patients for molecular analysis.