(CHICAGO, IL) – Regorafenib significantly prolongs progression-free survival (PFS) and disease control rate (DCS) among patients with advanced metastatic or unresectable gastrointestinal stromal tumor (GIST) that has progressed despite prior imatinib and sunitinib treatement, according to a randomized, double-blind, placebo-controlled Phase 3 study presented at the 2012 American Society of Clinical Oncology Annual Meeting.
“Regorafenib was well tolerated, with adverse events as expected for this class and manageable with dose modifications,” said lead author George D. Demetri, MD, Director, Center for Sarcoma and Bone Oncology, Dana-Farber Cancer Institute, Boston, MA.
Eligible patients had metastatic and/or unresectable GIST; medically-severe imatinib intolerance or objective progression on imatinib; progression of GIST on sunitinib; ≥1 measurable lesion; and ECOG performance status 0 or 1. Patients were randomized 2:1 to receive best supportive care plus either regorafenib (oral 160mg daily; 3 weeks on/1 week off; n=133), or placebo (n=66). Patients were stratified at randomization for number of prior systemic therapies and geographical region. Baseline characteristics were balanced between the two arms, Dr. Demetri reported.
Median PFS was significantly longer for patients in the regorafenib-arm than those in the placebo arm (4.8 vs. 0.9 months; HR=0.27; P<0.0001).
“PFS rates at 3 and 6 months were 60% and 38% for regorafenib versus 11% and 0% for placebo,” Dr. Demetri added. Regorafenib DCR was also superior to placebo (53% vs. 9%).
“It is immaterial whether patients were third-line or fourth, or higher,” Demetri said. “There’s a significant, robust effect regardless of the number of prior treatments.”
The most common grade 3+ treatment-emergent toxicities for regorafenib and placebo were hypertension (23.5% vs. 3%), hand-foot skin reaction (19.7% vs. 1.5%), and diarrhea (5.3% vs. 0%) Dr. Demetri reported.