Randomised Controlled Trial of Rivaroxaban Compared to Standard Anticoagulants for the Treatment of Acute Venous Thromboembolism in Children

Background: Treatment of venous thromboembolism (VTE) in children is based on data obtained in adults with little direct documentation of its efficacy and safety in children. Methods: In a parallel-group open-label randomised study, 500 children aged birth to 17 years with documented acute VTE who had started heparinisation were assigned, in a 2:1 ratio, to receive bodyweight-adjusted rivaroxaban (tablets or suspension) in a 20-mg equivalent dose or standard anticoagulants. The main treatment period was 3 months (1 month in children under 2 years with catheter-related VTE). Symptomatic recurrent VTE and bleeding were centrally assessed unaware of treatment assignment. Repeat imaging was obtained at the end of the treatment period. Findings: Recurrent VTE was the primary efficacy outcome and occurred in 4 of the 335 (1.2%) children allocated to rivaroxaban and in 5 of the 165 (3.0%) children allocated to standard anticoagulants (64.2% of whom received subcutaneous heparins only), for a hazard ratio of 0.40 (95% confidence interval, 0.11 to 1.41). Repeat imaging showed an improved effect of rivaroxaban on thrombotic burden as compared with standard anticoagulants (P=0.012). Major or clinically relevant non-major bleeding was the principal safety outcome and occurred in 10 children (3.0%; all non-major) with rivaroxaban and in 3 children (1.9%; two major and 1 non-major) with standard anticoagulants. Absolute and relative efficacy and safety estimates of rivaroxaban versus standard anticoagulation estimates were comparable those obtained in rivaroxaban studies in adults. Interpretation: In children with acute VTE, treatment with rivaroxaban resulted in a low recurrence risk and a reduced thrombotic burden without increased bleeding, as compared to standard anticoagulants. Trial Registration: This trial is registered with ClinicalTrials.gov, number NCT02234843. Funding Statement: Bayer AG and Janssen Research & Development, LLC. Declaration of Interests: CM reports receiving personal fees and fees, paid to his institution, from Bayer, Bristol-Myers-Squibb, Pfizer and fees, paid to his institution, from BoehringerIngelheim; AWAL being employed by Bayer; RK receiving personal fees from Bayer, CSL Behring, and Kedrion; DB receiving personal fees and grant support from Actelion Pharmaceuticals, Bayer, Eli Lilly, BMS, and Novartis and grant support from AbbVie; PC receiving personal fees from Onyx Health Limited; AKC receiving personal fees from Bayer and fees, paid to his institution, from Bayer, Pfizer, Daiichi Sankyo, and Bristol-Myers-Squibb; GK receiving personal fees from Bayer, Boehringer Ingelheim, and Daiichi-Sankyo and fees, paid to her institution from Pfizer; SH receiving personal fees from P and fees, paid to her institution, from Bayer, Pfizer, and Daiichi Sankyo; AS receiving personal fees from Bayer, Pfizer, Daiichi Sankyo and Boehringer Ingelheim; PA receiving personal fees and fees, paid to his institution, from Abbvie and Bayer, and fees paid to his institution from Actelion, Novartis, and Daiichi Sankyo; EC receiving personal fees from Boehringer Ingelheim and Bristol-Myers-Squibb, and fees, paid to her institution from Bayer, Pfizer, and Daiichi Sankyo; DLY receiving fees, paid to his institution, from Bayer, Pfizer, and Bristol-Myers Squibb; OL receiving personal fees from Bayer, Pfizer, Boehringer Ingelheim, and Novartis, and fees, paid to her institution, from Bayer; JB-W receiving personal fees and fees, paid to his institution, from Bayer, Daiichi Sankyo, DOASENSE and Portola and fees, paid to his institution, from Pfizer; TTB receiving fees from Boehringer Ingelheim and Bayer, and grant support from Leo Pharma; IM receiving fees from Sanofi and Bayer; MP receiving grant support from Pfizer and Sobi; MPM receiving personal fees from Bayer; GY receiving receiving personal fees from GlaxoSmithKline and Portola and personal fees and fees paid to his institution from Bayer and Daiichi Sankyo; AFP, MM, WTS, SDB, KT, DK being employed by Bayer; JH was employed by Bayer; MC receiving grant support from and serving on a data and safety monitoring board for Bayer, receiving advisory board fees from Shionogi, Octapharma, Bristol-Myers Squibb Canada, and Asahi Kasei, receiving educational funding from Alexion Pharmaceuticals, Pfizer, CSL Behring, and Diagnostica Stago, receiving grant support, paid to his institution, from Leo Pharma, serving on a data and safety monitoring board for Daiichi Sankyo, owning stock in Alnylam Pharmaceuticals, and receiving educational funding and advisory board fees from Servier Canada; MHP receiving personal fees from Bayer; no other potential conflict of interest relevant to this article was reported. Ethics Approval Statement: The protocol was approved by the institutional review board at each participating center. Written permission from a parent or guardian and, when appropriate, child assent, were obtained.