GIST: Molecular Profiling Suggests 2nd Therapy

Area of Science:

• Oncology
• Molecular Biology
• Genetics

Background:

• Advanced gastrointestinal stromal tumors (GIST) are rare.
• Imatinib is a standard first-line therapy, but resistance develops.
• Identifying specific genetic alterations in GIST is crucial for treatment selection.

Purpose of the Study:

• To investigate the efficacy of second-line treatments (ripretinib vs. sunitinib) based on specific KIT gene alterations in advanced GIST patients previously treated with imatinib.
• To highlight the clinical utility of circulating tumor DNA (ctDNA) analysis in guiding GIST therapy.

Main Methods:

• Analysis of ctDNA from patients with advanced GIST.
• Comparison of progression-free survival (PFS) and overall survival (OS) between patients receiving ripretinib or sunitinib as second-line therapy.
• Stratification of patients based on specific KIT exon alterations (11+17/18 vs. 11+13/14).

Main Results:

• Patients with KIT exon 11 plus 17 and/or 18 alterations showed superior PFS and OS with ripretinib compared to sunitinib.
• Patients with KIT exon 11 plus 13 and/or 14 alterations demonstrated superior PFS and OS with sunitinib compared to ripretinib.
• These findings underscore the importance of molecular profiling in advanced GIST.

Conclusions:

• Specific KIT exon alterations in advanced GIST predict differential responses to second-line therapies ripretinib and sunitinib.
• Molecular testing of ctDNA is a valuable tool for personalized treatment strategies in GIST.
• Tailoring therapy based on genetic mutations can improve patient outcomes in advanced GIST.