Regression of mutant adult glioblastoma after primary combined BRAF-MEK inhibitor targeted therapy: a report of two cases.

Background: Up to 15% of young adults with glioblastoma have the activating oncogenic mutation, an actionable target of the MAPK signal transduction pathway governing tumor cell proliferation. Small molecule inhibitors of BRAF and MEK, a downstream protein immediately following BRAF, have been shown to confer a survival advantage for patients with mutant advanced melanoma. We describe our experience using this combined target therapy for two patients with BRAF mutant glioblastoma (GBM) as primary treatment due to extenuating clinical circumstances that prohibited the prescription of standard treatment.