Adjuvant Imatinib in Patients with GIST Harboring Exon 9 KIT Mutations : Results from a Multi-institutional European Retrospective Study
[Purpose] The effect of high-dose imatinib (800 mg/day) on survival in the adjuvant treatment of patients with resected KIT exon 9–mutated gastrointestinal stromal tumors (GIST) is not established. Here, the association of dose and other clinicopathologic variables with survival was evaluated in a large multi-institutional European cohort.
A Phase 2 Trial of Ixabepilone in Asian Patients with Advanced Gastric Cancer Previously Treated with Fluoropyrimidine-Based Chemotherapy
ABSTRACT Background The highest rates of gastric cancer occur in Eastern Asia. Fluoropyrimidine-based therapy is used initially in unresectable and metastatic disease, following progression, 60–70% of patients in Asian countries subsequently receive second-line chemotherapy. However, there is no standard treatment in this setting. Ixabepilone, an epothilone B analog, is a non-taxane microtubule-stabilizing agent with clinical anti-tumor activity across multiple tumor types. We evaluated the efficacy and safety of single-agent ixabepilone as a second-line chemotherapy in Asian patients. Methods Asian patients with unresectable or metastatic gastric adenocarcinoma who had failed previous fluo…
Randomized Phase 3 Trial of Regorafenib in Patients (Patients) with Metastatic and/or Unresectable Gastrointestinal Stromal Tumor (GIST) Progressing Despite Prior Treatment with at Least Imatinib (IM) and Sunitinib (SU) : Grid Trial
LBA10008 Background: Oral multikinase inhibitor regorafenib (REG) demonstrated substantial activity in a phase II trial in pts with GIST after failure of both IM and SU (J Clin Oncol. 2011; 29:606s; abstr 10007). This phase III, randomized, double-blind, placebo-controlled trial evaluated the efficacy and safety of REG for this unmet clinical need. Methods: Eligible pts had metastatic and/or unresectable GIST, objective failure of both prior IM and SU (progressive disease [PD] on, or intolerance to, IM and PD on SU), ≥1 measurable lesion, ECOG performance status 0 or 1. Pts were randomized 2:1 to receive best supportive care plus either REG 160 mg po once daily (3 wks on/1 wk off) or placeb…
Mammary-derived growth inhibitor (MDGI) interacts with integrin α-subunits and suppresses integrin activity and invasion
The majority of mortality associated with cancer is due to formation of metastases from the primary tumor. Adhesion mediated by different integrin heterodimers has an important role during cell migration and invasion. Protein interactions with the β1-integrin cytoplasmic tail are known to influence integrin affinity for extracellular ligands, but regulating binding partners for the α-subunit cytoplasmic tails have remained elusive. In this study, we show that mammary-derived growth inhibitor (MDGI) (also known as FABP-3 or H-FABP) binds directly to the cytoplasmic tail of integrin α-subunits and its expression inhibits integrin activity. In breast cancer cell lines, MDGI expression correlat…
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…
Abstract LB-295: Detection of oncogenic kinase mutations in circulating plasma DNA and correlation with clinical benefit in the phase III GRID study of regorafenib vs placebo in TKI-refractory metastatic GIST.
Abstract Background: GRID is a phase III study for patients with advanced gastrointestinal stromal tumors (GIST) following failure of imatinib (I) and sunitinib (S) who were randomized to receive either the multikinase inhibitor regorafenib (R) or placebo (P). R demonstrated a highly significant improvement in progression-free survival compared with P (HR 0.27, p&lt;0.0001). A preplanned retrospective biomarker analysis was conducted to assess GIST genotypes in GRID patients and to explore the possible impact of different driver oncogene mutations on clinical outcomes. Methods: DNA was isolated from archival tumor tissue and analyzed for KIT mutations via Sanger sequencing. The expectat…
Role of adjuvant imatinib dose in radically resected GIST harboring KIT exon 9 mutations
11533 Background: Gastrointestinal stromal tumors (GIST) with a driver mutation in KIT exon 9 (Ex9) represent about 10% of all newly diagnosed cases. In the metastatic setting, Ex9-mutated GIST patients benefit from higher doses of imatinib (800 mg/day vs standard 400 mg/day). The additional therapeutic benefit from a higher dose of imatinib in the adjuvant setting in this molecular subgroup has not been confirmed. Methods: We retrospectively identified 105 patients (pts) with resected Ex9-mutated GIST treated with adjuvant imatinib (800 mg/day or 400 mg/day) in 15 different European centers. Disease-Free Survival (DFS) and Imatinib Failure-Free Survival (IFFS) were calculated and analyzed…