Rivaroxaban trumps dabigatran, apixaban for VTE prophylaxis
MedWire News: Rivaroxaban may be more efficient than dabigatran and apixaban for venous thromboembolism prophylaxis in patients undergoing orthopedic surgery, indicate the results of an indirect comparison by network meta-analysis (NETMA).
In the development of novel pharmaceuticals, there is an increasing frequency of situations where two or more new agents have been compared with standard therapy based on a randomized controlled trial (RCT), but a head-to-head (direct) comparison between the novel treatments is lacking, explain Andrea Messori (Regional Health System, Prato, Italy) and colleagues.
As a result, new techniques are being explored that generate indirect statistical comparisons between novel treatments that have not been compared with each other in clinical trials.
Network meta-analysis (NETMA) is one such technique. Messori and team used NETMA to indirectly compare the efficacy of three novel oral anticoagulants: dabigatran, rivaroxaban, and apixaban. These agents have typically been tested against the standard therapy of enoxaparin 40 mg daily in clinical trials.
The researchers identified eight RCTs that compared dabigatran, rivaroxaban, or apixaban with enoxaparin in patients undergoing primary elective total hip or knee replacement.
They applied a simplified NETMA to the data to calculate the risk ratio (RR) for the composite clinical endpoint of symptomatic or asymptomatic deep vein thrombosis (DVT), nonfatal pulmonary embolism (PE), and/or all-cause mortality.
Direct comparisons of apixaban 2.5 mg daily, rivaroxaban 10 mg daily, and dabigatran 220 mg daily with enoxaparin 40 mg daily yielded pooled RRs for the composite endpoint of 0.56, 0.39, and 0.93, respectively. This indicates that each of the new anticoagulants conferred a lower risk for symptomatic or asymptomatic DVT, nonfatal PE, and/or all-cause mortality than standard therapy.
Indirect comparison using NETMA resulted in a RR of 0.70 for rivaroxaban versus apixaban, 1.66 for dabigatran versus apixaban, and 2.38 for dabigatran versus rivaroxaban.
"Our results indicate that, despite the indirect nature of this type of evidence and the limitations of this technique, rivaroxaban tends to be more effective than the other two innovative oral anticoagulants (dabigatran and apixaban) and proves also to be superior to enoxaparin on the basis of a direct comparison," write Messori and co-authors in the Journal of Thrombosis and Haemostasis.
"Of course, whether this statistical superiority translates into a clinically relevant difference still remains to be established," they add.
MedWire (www.medwire-news.md) is an independent clinical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2011
By Laura Dean