Biosimilar versus branded enoxaparin to prevent postoperative venous thromboembolism after surgery for digestive tract cancer: Randomized trial

Cancer and/or major surgery are two factors that predispose to post-operative thrombosis. The annual incidence of venous thromboembolic disease (VTED) in cancer patients was estimated at 0.5%-20%. Surgery increases the risk of VTED by 29% in the absence of thromboprophylaxis. Enoxaparin is a low molecular weight heparin that is safe and effective. Branded Enoxaparin and biosimilar Enoxaparin are two enoxaparin treatments. This study aimed to compare Branded Enoxaparin with biosimilar Enoxaparin in patients operated on for digestive cancer regarding the prevention of postoperative thrombosis event, to compare the tolerance of the two treatments and to identify independent predictive factors of thromboembolic incident. A randomized controlled trial conducted in a single-centre, surgical department B of Charles Nicolle Hospital, over a 5-year period from October 12th, 2015, to July 08th, 2020. We included all patients over 18 who had cancer of the digestive tract newly diagnosed, operable and whatever its nature, site, or stage, operated on in emergency or elective surgery. The primary endpoint was any asymptomatic thromboembolic event, demonstrated by systematic US Doppler of the lower limbs on postoperative day 7 to day 10. The sonographer was unaware of the prescribed treatment (Branded Enoxaparin [BE] or biosimilar Enoxaparin [BSE]). Of one hundred sixty-eight enrolled patients, six patients (4.1%) had subclinical venous thrombosis. Among those who had subclinical thrombosis, four patients (5.6%) were in the Branded Enoxaparin group and two patients (2.7%) in the Biosimilar Enoxaparin group without statistically significant difference (p = 0.435). Analysis of the difference in means using Student's t test demonstrated the equivalence of the two treatments. Our study allowed us to conclude that there was no statistically significant difference between Branded Enoxaparin and Biosimilar Enoxaparin regarding the occurrence of thromboembolic accidents postoperatively. BE and BSE are equivalent.Trial registration. Trial registration: The trial was registered on CLINICALTRIALS.GOV under the number NCT02444572.