0000000000779176
AUTHOR
Michael G Leahy
Results from a phase III trial (GRID) evaluating regorafenib (REG) in metastatic gastrointestinal stromal tumour (GIST): Subgroup analysis of outcomes based on pretreatment characteristics
10551 Background: REG, an oral receptor kinase inhibitor with activity against KIT, PDGFR, VEGFR, FGFRs, and other oncologic targets, demonstrated significant improvement in progression-free survival (PFS) over placebo (PL) in a phase III study (GRID) of patients (pts) with advanced GIST following failure of at least imatinib (IM) and sunitinib (SU). To understand the impact of pts’ baseline characteristics on outcome, we performed an exploratory analysis of REG effects across pt subgroups based on sex, age, and mitotic index of primary GIST tissue, as well as duration and number of lines of previous therapies. Methods: Adult pts with metastatic GIST (n=199) progressing after at least IM a…
Mutational analysis of plasma DNA from patients (pts) in the phase III GRID study of regorafenib (REC) versus placebo (PL) in tyrosine kinase inhibitor (TKI)-refractory GIST: Correlating genotype with clinical outcomes
10503 Background: The phase III GRID study showed that REG provides a significant improvement in progression-free survival (PFS) compared with PL in pts with advanced gastrointestinal stromal tumors (GIST) following failure of at least imatinib (IM) and sunitinib (SU; HR 0.27, p<0.0001). Determining GIST genotype in TKI-refractory disease has proven challenging due to inter-tumoral heterogeneity and pt preference to avoid serial biopsies. To overcome this, we analysed circulating DNA in plasma as a source of tumor DNA and studied the correlation between mutational status and clinical outcome. Methods: DNA was isolated from both archival tumor tissue (n=102) and plasma at baseline (n=163…