Nearly 2 years after their presentation at a national meeting, the results of MAGELLAN, comparing rivaroxaban to enoxaparin for thromboprophylaxis in critically ill hospitalized patients, have been published online Feb. 6 in the New England Journal of Medicine.
In that large, multicenter trial, rivaroxaban was noninferior to enoxaparin when used for the standard 10-day duration, and superior when used for an extended 35-day duration, for thromboprophylaxis.
However, the rate of clinically relevant bleeding and the incidence of major bleeding events were significantly higher with rivaroxaban than with enoxaparin. This adverse effect apparently balanced out the reduction in venous thromboembolism, as a prespecified analysis of net clinical benefit and harm did not show either one at day 10 or day 35, reported Dr. Alexander T. Cohen and his associates in MAGELLAN (Multicenter, Randomized, Parallel Group Efficacy and Safety Study for the Prevention of Venous Thromboembolism in Hospitalized Acutely Ill Medical Patients Comparing Rivaroxaban with Enoxaparin). The results were first presented by Dr. Cohen, of King's College Hospital, London, at the annual meeting of the American College of Cardiology in spring 2011.
In the 2.5-year study, 8,101 patients at 556 sites in 52 countries were randomized to receive rivaroxaban (4,050 subjects) or enoxaparin (4,051 subjects). Hundreds of patients in both study groups were excluded from the final analyses for various reasons, usually because they could not be assessed for venous thromboembolism using ultrasonography and other imaging techniques in a timely fashion, as required by the study protocol.
At 10 days' follow-up, 2.7% of patients in both groups had a primary outcome event - asymptomatic proximal deep vein thrombosis (DVT), symptomatic nonfatal pulmonary embolism (PE), or thromboembolism-related death - so rivaroxaban met the criteria for noninferiority to enoxaparin.
At the 35-day follow-up, 4.4% of subjects who received extended-duration rivaroxaban and 5.7% of those who received enoxaparin plus placebo had a primary outcome event, so rivaroxaban met the criteria for superiority to enoxaparin, the investigators reported (N. Engl. J. Med. 2013 Feb. 6 [doi: 10.1056/NEJMoa1111096]).
Rivaroxaban (Xarelto)has several indications: for stroke prevention in nonvalvular atrial fibrillation, for the treatment of DVT and PE, for reducing the risk of recurrence of DVT and PE, and for the prophylaxis of DVT in patients undergoing knee or hip replacement surgery. It is not indicated for the condition studied in MAGELLAN, namely prevention of VTE in acutely medically ill patients.
This study was funded by Bayer HealthCare and Janssen, sponsors that also collected and analyzed the study data. Dr. Cohen and his associates reported numerous ties to industry sources.
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