TIE1 and gastrointestinal stromal tumor: Regorafenib is an oral multi-targeted inhibitor with activity against multiple kinases, including KIT, RET, RAF1 and BRAF, as well as those involved in angiogenesis (VEGFR and TIE-2) and in tumour support from the microenvironment (PDGFR and FGFR).35 The GRID study, a randomised, Phase 3 trial with regorafenib monotherapy in progressive GIST, reported a median PFS of 4.8 months (hazard ratio, 0.27; 95% CI, 0.19–0.39; P < 0.0001) when treated with the active compound in the third line.36 Regorafenib was shown to significantly improve PFS and DCR compared with placebo.