SEARCH

SEARCH BY CITATION

Keywords:

  • VEGF;
  • Hypertension;
  • Receptor tyrosine kinase;
  • Ejection fraction;
  • Sunitinib

SUMMARY

Background: Sunitinib, a multi-tyrosine kinase inhibitor has demonstrated clinical activity in advanced renal cell carcinoma and imatinib-resistant/intolerant gastrointestinal stromal tumor. It has been associated with manageable hypertension and other unique toxicities. Aims: Two nonclinical studies were conducted to determine if sunitinib has direct/indirect effects on cardiac structure/function that may be related to hypertension at clinically relevant exposures. Materials & Methods: Rats received once-daily vehicle or sunitinib 1 or 10 mg/kg/day (n = 10/group) orally for 4 weeks, followed by 2 weeks off treatment then a 2-week rechallenge. Blood pressure (BP) and heart rate (HR) were continuously acquired and echocardiograms were obtained weekly. Effects of sunitinib and its metabolite (0.003–0.3 μM) were also evaluated in guinea pig isolated Langendorff-perfused hearts (n = 4–6 hearts/group). Results: Sunitinib 10 mg/kg/day produced significant (P < 0.05) hemodynamic changes: 24 h average BP increased during initial dosing/rechallenge, with rebound hypotension during the off-treatment period; 24 h average HR increased during the off-treatment period, and decreased during rechallenge; no changes in cardiac structure/function were observed. In guinea pig isolated hearts, neither sunitinib nor its metabolite had direct effects on contractility, HR or left ventricular pressure. Discussion & Conclusion: These studies demonstrate that sunitinib/metabolite had no direct effects on cardiac function ex vivo, and that therapeutically relevant concentrations of sunitinib dosed on a “clinical schedule” increased BP in rats without adverse changes in cardiac structure/function.