...1.Age 18-75 years old, male or female; 2.GIST tumor is primary, no distant metastasis was found in preoperative examination and intraoperative exploration; 3.No targeted drug neoadjuvant therapy before operation; 4.Accepted Radical R0 surgical resection; 5.Postoperative pathologically confirmed soft tissue tumor, in line with GIST; 6.Genetic testing (first- or second-generation sequencing) confirmed PDGFRα Exon18 D842V mutation, and the remaining sites were detected c-kit (Exon-9, Exon-11, Exon-13, Exon-17) and PDGFRα (Exon-12) have no mutation; 7.Have understood and signed the informed consent....

CONTRADICTING EVIDENCE: KIT molecular subgroups and outcomes were determined in pts with primary KIT mutations treated with oral avapritinib 300 mg once daily (starting dose) enrolled in the phase 1 NAVIGATOR (NCT02508532) and phase 1/2 (China bridging) trials (NCT04254939, CS3007-101)....In pts with KIT 9 mutations in the 4L (n = 14) and > 4L settings (n = 19), mPFS was 5.6 and 3.7 months, respectively....The results suggest that avapritinib could confer meaningful clinical benefit in pts with GIST and specific KIT mutation types, especially KIT-AL or KIT 9 mutations.

A 40-year-old male with gastric GIST and liver metastases (c-KIT exon 9 mutation positive)...After a discussion in the tumor board, avapritinib was started. He received avapritinib for 1 month, with a treatment interruption of 3 months due to an ongoing corona pandemic. He was again restarted on the avapritinib, however response assessment at 1 month showed PD.