Medicine and Health Sciences Commons^™

Response And Resistance To Paradox-Breaking Braf Inhibitor In Melanomas, Edward J. Hartsough, Curtis H. Kugel, Michael J. Vido, Adam C. Berger, Timothy J. Purwin, Allison F. Goldberg, Michael A. Davies, Matthew J. Schiewer, Karen E. Knudsen, Gideon Bollag, Andrew E. Aplin

Department of Cancer Biology Faculty Papers

FDA-approved BRAF inhibitors produce high response rates and improve overall survival in patients with BRAF V600E/K-mutant melanoma, but are linked to pathologies associated with paradoxical ERK1/2 activation in wild-type BRAF cells. To overcome this limitation, a next-generation paradox-breaking RAF inhibitor (PLX8394) has been designed. Here, we show that by using a quantitative reporter assay, PLX8394 rapidly suppressed ERK1/2 reporter activity and growth of mutant BRAF melanoma xenografts. Ex vivo treatment of xenografts and use of a patient-derived explant system (PDeX) revealed that PLX8394 suppressed ERK1/2 signaling and elicited apoptosis more effectively than the FDA-approved BRAF inhibitor, vemurafenib. Furthermore, PLX8394 was …