KIT exon 13 mutation

Secondary KIT mutations play a crucial role in imatinib resistance and the efficacy of second- and third-line therapies. Genetic profiling at the initial diagnosis and at the time of resistance may provide more personalized and effective treatment strategies.

90Y-SIRT is a potent treatment for patients with liver metastases of GIST resistant to TKI therapy. In patients with 'q-wt' GIST, SIRT is an option for first-line use.

55% (42/77) of liquid samples with a KIT-driver mutation had a co-occurring imatinib-resistant alteration; a minority of cases harbored non-KIT mechanisms of resistance such as FGFR2 fusion, BRAF or EGFR alterations...In conclusion, known driver and TKI-resistant mutations were identified in liquid biopsies of GIST patients with high concordance to tissue in the presence of elevated TF. Liquid biopsy may be valuable in the molecular classification and medical management of GIST.

55% (42/77) of liquid samples with a KIT -driver mutation had a co-occurring imatinib-resistant alteration, and a minority of cases harbored non- KIT mechanisms of resistance such as FGFR2 fusion, BRAF or EGFR alterations... Known driver and TKI-resistant mutations are identified in liquid biopsies of patients with GIST, with high concordance to tissue in the presence of elevated TF. Liquid biopsy may be valuable in the molecular classification of GIST during the medical management of advanced disease.

INTRIGUE was an open-label, phase 3 study in adult patients with advanced gastrointestinal stromal tumor who had disease progression on or intolerance to imatinib and who were randomized to once-daily ripretinib 150 mg or sunitinib 50 mg. The results of this exploratory analysis suggest ctDNA sequencing may improve the prediction of the efficacy of single-drug therapies and support further evaluation of ripretinib in patients with KIT exon 11 + 17/18 mutations. ClinicalTrials.gov identifier: NCT03673501.

Avapritinib showed greater antitumor activity in patients with GISTs harboring KIT ALposABPneg mutations versus KIT OTHERS, and may be considered in the former subpopulation. Patients with KIT exon 9 mutations may also benefit in ³4 line settings.

While KIT ATP-BP mutations were associated with clinical benefit from sunitinib vs ripretinib, pts harboring resistance mutations in the KIT AL derived meaningful clinical benefit from ripretinib but not sunitinib. This study demonstrates the value of ctDNA NGS-based sequencing of KIT mutations to predict the clinical benefit of second-line therapy in pts with advanced GIST. These data were presented in part at the Jan 2023 ASCO plenary session.

P2, N=48, Recruiting, University of Miami | Trial completion date: Jul 2028 --> Dec 2028 | Trial primary completion date: Jul 2026 --> Dec 2026

As sunitinib and regorafenib are only effective against certain secondary mutations, ripretinib can broadly inhibit a wide range of primary and secondary KIT mutations. The proportion of secondary mutations in KIT Exon 11 primary mutations is significantly higher than that in KIT Exon 9 primary mutations following progression on first-line imatinib treatment. Furthermore, the main resistance mechanism of KIT Exon 11 mutant GISTs continues to rely on complex secondary mutations in KIT signaling. Differences in resistance mechanisms among various primary mutations imply that subsequent treatment should take into account both the patient 's primary and resistance mutations.

uPARAP is highly expressed in several GIST xenograft models across multiple passages of ex-mouse tumors. Considering its preferential expression in GIST and other mesenchymal tumors and the recycling character of this molecular target, uPARAP may serve as a powerful emerging target for systemic treatment of GIST beyond traditional kinase inhibitors or in combination with the latter. uPARAP positive xenograft models can be used for in vivo evaluation of such anti-uPARAP treatment.

Different KIT mutation types and signaling pathways atlerations were detected in progression samples of KIT-mutant GISTs after avapritinib or ripretinib failure compared with baseline, which may be associated with mechanism of resistance.

This study represents a one of the most comprehensive analyses of the genomic landscape and integration of genomic features with clinicopathologic attributes and survival outcome in GIST.