A metastatic colon adenocarcinoma harboring BRAF V600E has a durable major response to dabrafenib/trametinib and chemotherapy

Abstract

Casey B Williams,1,* Caitlin McMahon,2,* Siraj M Ali,2 Mark Abramovitz,1 Kirstin A Williams,1 Jessica Klein,1 Heidi McKean,1 Roman Yelensky,2 Thomas J George Jr,3 Julia A Elvin,2 Salil Soman,4 Doron Lipson,2 Juliann Chmielecki,2 Deborah Morosini,2 Vincent A Miller,2 Philip J Stephens,2 Jeffrey S Ross,2,5 Brian Leyland-Jones1 1Avera Cancer Institute, Sioux Falls, SD, USA; 2Foundation Medicine, Inc., Cambridge, MA, USA; 3University of Florida College of Medicine, Gainesville, FL, USA; 4Beth Israel Deaconess Medical Center, Boston, MA, USA; 5Albany Medical College, Albany, NY, USA *These authors contributed equally to this work Abstract: The subset of metastatic colorectal adenocarcinomas that harbor BRAF V600E mutations are aggressive tumors with significantly shortened survival and limited treatment options. Here we present a colorectal cancer patient whose disease progressed through standard chemotherapy and who developed liver metastasis. Comprehensive genomic profiling (FoundationOne®) identified a BRAF V600E mutation in the liver lesion, as well as other genomic alterations consistent with colorectal cancers. Combination therapy of dabrafenib and trametinib with standard cytotoxic chemotherapy resulted in a durable major ongoing response for the patient. This report illustrates the utility of comprehensive genomic profiling with personalized targeted therapy for aggressive metastatic colorectal adenocarcinomas. Keywords: oxaliplatin, colorectal adenocarcinoma, combination targeted therapy, BRAF mutations