Robin L. Jones, Johanna C. Bendell, David C. Smith, Konstanze Diefenbach, John Lettieri, Oliver Boix, A. Craig Lockhart, Cindy O’Bryant, Kathleen N. Moore

To characterize the cardiovascular safety profile of regorafenib in patients with advanced cancer. Patients received regorafenib 160 mg/day for 21 days followed by a 7-day break. The primary endpoint was the change from baseline in QTcF at the regorafenib t max (Day 21, Cycle 1 or 2) and changes in left ventricular ejection fraction (LVEF) from baseline on Cycle 2, Day 21. Secondary objectives were pharmacokinetics, safety, anti-tumor activity and effects on electrocardiogram intervals. QT intervals were corrected using the methods of Fridericia (QTcF) and Bazett (QTcB). LVEF was assessed by multigated acquisition scanning. Fifty-three patients were enrolled, and all received at least one dose of regorafenib 160 mg. Twenty-five patients received regorafenib for 21 days without dose reduction. The mean change from baseline in QTcF at t max was (-)2 ms (90 % CI -8, 3). No patient experienced a change from baseline in QTcF > 60 ms, and two had QTcF changes between 30 and 60 ms. No patient had a QTcF or QTcB > 480 ms. In 27 patients who received at least 80 mg of regorafenib, the mean change from baseline in LVEF% ± SD was 1.7 ± 7.8. In 14 patients without a dose reduction, the mean change from baseline in LVEF% was (-)0.1 ± 8.6 at Cycle 2, Day 21. Four patients experienced a LVEF decrease between 10 and 20 %. The effects of regorafenib on the QT/QTc interval and LVEF were modest and unlikely to be of clinical significance in the setting of advanced cancer therapy.