A phase II study of the 5-lipoxygenase inhibitor, CV6504, in advanced pancreatic cancer: Correlation of clinical data with pharmacokinetic and pharmacodynamic endpoints

Purpose: Primary objective was to determine response rate of patients with advanced pancreatic cancer to a novel lipoxygenase and thromboxane A2 synthetase inhibitor (CV6504); secondary objectives included estimation of pharmacokinetics of CV6504, target-enzyme inhibition, safety and tolerance, quality of life and survival. Patients and methods: Thirty-one patients with advanced pancreatic cancer were planned to receive CV6504, 100 mg TDS, orally for three months, at which point CT scans were performed to assess therapeutic response rates. Steady state concentrations of CV6504 and thromboxane B2 (an indirect measure of thromboxane A2 synthetase (TA(2)S) inhibition) were made. Of the 31 patients entered into the study, 23 were considered fully evaluable for response. Results: The drug was well tolerated with few side effects; no partial or complete responses were seen, but 10 patients had stable disease at 3 months; quality of life was maintained during therapy; mean CV6504 steady state plasma concentrations of 14 +/- 6 ng/ml resulting in 75 +/- 18% inhibition of TA(2)S were achieved; median-survival time for all patients considered eligible for assessment of efficacy was 36.6 weeks after the initial dose of study medication. The actuarial one-year survival was approximately 25%. Conclusion: CV6504 inhibits its target enzyme in vivo, maintains stable disease in 32% of evaluable patients and is well tolerated.