Comparing Regorafenib Combined With Envafolimab to Physician's Choice in Patients With Metastatic Gastrointestinal Stromal Tumors Harboring KIT Exon 17 Mutations Refractory to Standard Treatment

Gastrointestinal stromal tumors (GISTs) are mostly driven by c-kit or PDGFRA mutations, and commonly occur in the stomach and small intestine. Targeted therapy is the mainstay for advanced metastatic GISTs, but there is a lack of effective regimens after drug resistance. Immune checkpoint inhibitors (ICIs) have limited efficacy as monotherapy, while tyrosine kinase inhibitor (TKI) drugs such as regorafenib can improve the immune microenvironment and exert a synergistic effect when combined with ICIs, with more significant efficacy especially in cases with kit exon 17 mutations. This study aims to explore the effectiveness of regorafenib combined with envafolimab in metastatic gastrointestinal stromal tumors with kit exon 17 mutations that have failed standard treatment.