Regorafenib is an oral multi-kinase inhibitor, which targets angiogenic (VEGFR, TIE-2), stromal (PDGFR-ß) and oncogenic (RAF, RET and KIT) receptor tyrosine kinases.
The randomised, double-blind, placebo-controlled, multi-centre, cross-over Phase III study will enroll approximately 170 patients whose cancer has progressed after initial treatment with at least imatinib and sunitinib as prior treatment regimens.
For the study, patients will be randomised in 2:1 ratio to receive either regorafenib 160mg or placebo.
Patients receiving placebo who experience disease progression will be allowed to switch to open label regorafenib treatment (cross over option).
The primary endpoint of the trial will be progression-free survival (PFS), while the secondary endpoints include overall survival (OS), time to progression (TTP), disease control rate (DCR), tumour response rate (RR), duration of response (DOR), and safety.
Bayer Schering Pharma head of Global Development Kemal Malik said currently there are limited treatment options available for patients whose GIST tumours have progressed after imatinib and sunitinib.
"Bayer is committed to its ongoing efforts to improve the lives of people with cancer, and the initiation of a Phase III clinical trial for regorafenib is a critical step towards a potential new treatment option for GIST patients," Malik said.