Complete radiological response to first-line regorafenib in a patient with abdominal relapse of BRAF V600E mutated GIST:

Up to 13% ofKITandPDGFRAwild-type (WT) gastrointestinal stromal tumours (GIST) harbour a BRAF mutation, mostly involving the exon 15V600Ehot spot. Even ifBRAFmutation is recognized as druggable target in other solid tumours, currently advancedBRAF-mutant GIST share the same therapeutical algorithm ofKIT/PDGFRAmutants. We report a complete radiological response in a 51-year-old woman with V600E BRAF-mutated metastatic GIST who was treated with regorafenib (REG) as first-line therapy. REG represents the standard third-line therapy for advanced GIST patients progressing on or failing to respond to imatinib and sunitinib. However, according to its wide spectrum of action, withMAPKsignalling pathway blockade at different levels, metastaticKIT/PDGFRAWT, includingBRAFmutants, may benefit from REG upfront in first line.