CATCH: A randomized trial comparing tinzaparin versus warfarin for treatment of acute venous thromboembolism (VTE) in cancer patients.

Abstract

TPS9149^ Background: VTE is a major cause of morbidity and mortality in cancer patients. LMWHs have been shown to be superior to warfarin in one randomized study, but adequately powered confirmatory studies have not been conducted and warfarin continues to be widely used for treatment of cancer-associated VTE. Methods: We are conducting an open-label, randomized trial of tinzaparin versus warfarin in 900 patients with active cancer and symptomatic proximal deep vein thrombosis (DVT) and/or pulmonary embolism (PE). Tinzaparin is given at full treatment doses (175 IU/kg once daily) for 6 months in the experimental arm and initial tinzaparin treatment for 5-10 days followed by dose-adjusted warfarin (target INR 2.0-3.0) is given for 6 months in the control arm. The primary composite outcome is time to recurrent VTE event, including incidentally diagnosed VTE and fatal PE. Baseline characteristics will be analysed for their ability to predict the risk for recurrent VTE or bleeding. In particular, the parameters of the Khorana scale and Wells rule will be tested for their usefulness in predicting recurrent VTE. Predictive biomarkers will be tested including D-dimer and Tissue Factor. Assessment of post-thrombotic syndrome (PTS), quality of life and healthcare resource utilization will also be performed. The trial is recruiting in > 160 sites in >25 countries in 4 continents (NCT01130025). As of Jan 2012, 135 sites were activated for study enrolment and 228 patients have been enrolled. We anticipate completion of enrolment in Jan 2013. The results obtained from this study will add significantly to the knowledge on the efficacy, safety and cost-effectiveness of LMWH to prevent recurrent VTE. Important prospective data on the clinical significance of incidental VTE in patients with active cancer will be generated, and analyses of risk stratification parameters will add important information that may help to further tailor therapy. The study of PTS, which has not previously been done in this selected patient population, will add to the evidence that tinzaparin significantly reduces the incidence of PTS and leg ulcers (Hull et al, Am J Med 2009;122:762-9).