Enoxaparin versus dalteparin or tinzaparin in patients with cancer and venous thromboembolism: The RIETECAT study

Background: Venous thromboembolism (VTE) is a frequent complication in patients with cancer and a leading cause of morbidity and death. Objectives: The objective of the RIETECAT study was to compare the long-term effectiveness and safety of enoxaparin versus dalteparin or tinzaparin for the secondary prevention of VTE in adults with active cancer. Methods: We used the data from the multicenter, multinational RIETE registry to compare the rates of VTE recurrences, major bleeding, or death over 6 months in patients with active cancer and acute VTE using full doses of enoxaparin versus dalteparin or tinzaparin, and a multivariable Cox proportional hazard model was used to analyze the primary end point. Results: From January 2009 to June 2018, 4451 patients with active cancer received full doses of the study drugs: enoxaparin, 3526 patients; and dalteparin or tinzaparin, 925 (754 + 171) patients. There was limited difference in VTE recurrences (2.0% vs 2.5%) and mortality rate (19% vs 17%) between the enoxaparin and dalteparin or tinzaparin subgroups. However, there was a slight numerical increase in major bleeding (3.1% vs 1.9%). Propensity score matching confirmed that there were no differences in the risk for VTE recurrences (adjusted hazard ratio [aHR], 0.81; 95% confidence interval [CI], 0.48-1.38), major bleeding (aHR, 1.40; 95% CI, 0.80-2.46), or death (aHR, 1.07; 95% CI, 0.88-1.30) between subgroups. Conclusions: In RIETECAT, in patients with cancer and VTE receiving full-dose enoxaparin or dalteparin or tinzaparin, no statistically significant differences were observed regarding effectiveness and safety outcomes over a 6-month period.