Peri-procedural use of rivaroxaban in elective percutaneous coronary intervention to treat stable coronary artery disease. The X-PLORER trial.

Patients on rivaroxaban requiring percutaneous coronary intervention (PCI) represent a clinical conundrum. We aimed to investigate whether rivaroxaban, with or without an additional bolus of unfractionated heparin (UFH), effectively inhibits coagulation activation during PCI. Stable patients (n=108) undergoing elective PCI and on stable dual antiplatelet therapy were randomised (2:2:2:1) to a short treatment course of rivaroxaban 10 mg (n=30), rivaroxaban 20 mg (n=32), rivaroxaban 10 mg plus UFH (n=30) or standard peri-procedural UFH (n=16). Blood samples for markers of thrombin generation and coagulation activation were drawn prior to and at 0, 0.5, 2, 6-8 and 48 hours (h) after start of PCI. In patients treated with rivaroxaban (10 or 20 mg) and patients treated with rivaroxaban plus heparin, the levels of prothrombin fragment 1 + 2 at 2 h post-PCI were 0.16 [0.1] nmol/l (median) [interquartile range, IQR] and 0.17 [0.2] nmol/l, respectively. Thrombin-antithrombin complex values at 2 h post-PCI were 3.90 [6.8]µg/l and 3.90 [10.1] µg/l, respectively, remaining below the upper reference limit (URL) after PCI and stenting. This was comparable to the control group of UFH treatment alone. However, median values for thrombin-antithrombin complex passed above the URL with increasing tendency, starting at 2 h post-PCI in the UFH-alone arm but not in rivaroxaban-treated patients. In this exploratory trial, rivaroxaban effectively suppressed coagulation activation after elective PCI and stenting.

Rivaroxaban versus placebo in patients with acute coronary syndromes (ATLAS ACS-TIMI 46): a randomised, double-blind, phase II trial.

BACKGROUND: Rivaroxaban is an oral direct factor Xa inhibitor that has been effective in prevention of venous thromboembolism in patients undergoing elective orthopaedic surgery. However, its use after acute coronary syndromes has not been investigated. In this setting, we assessed the safety and efficacy of rivaroxaban and aimed to select the most favourable dose and dosing regimen. METHODS: In this double-blind, dose-escalation, phase II study, undertaken at 297 sites in 27 countries, 3491 patients stabilised after an acute coronary syndrome were stratified on the basis of investigator decision to use aspirin only (stratum 1, n=761) or aspirin plus a thienopyridine (stratum 2, n=2730). Participants were randomised within each strata and dose tier with a block randomisation method at 1:1:1 to receive either placebo or rivaroxaban (at doses 5-20 mg) given once daily or the same total daily dose given twice daily. The primary safety endpoint was clinically significant bleeding (TIMI major, TIMI minor, or requiring medical attention); the primary efficacy endpoint was death, myocardial infarction, stroke, or severe recurrent ischaemia requiring revascularisation during 6 months. Safety analyses included all participants who received at least one dose of study drug; efficacy analyses were by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00402597. FINDINGS: Three patients in stratum 1 and 26 in stratum 2 never received the study drug. The risk of clinically significant bleeding with rivaroxaban versus placebo increased in a dose-dependent manner (hazard ratios [HRs] 2.21 [95% CI 1.25-3.91] for 5 mg, 3.35 [2.31-4.87] for 10 mg, 3.60 [2.32-5.58] for 15 mg, and 5.06 [3.45-7.42] for 20 mg doses; p<0.0001). Rates of the primary efficacy endpoint were 5.6% (126/2331) for rivaroxaban versus 7.0% (79/1160) for placebo (HR 0.79 [0.60-1.05], p=0.10). Rivaroxaban reduced the main secondary efficacy endpoint of death, myocardial infarction, or stroke compared with placebo (87/2331 [3.9%] vs 62/1160 [5.5%]; HR 0.69, [95% CI 0.50-0.96], p=0.0270). The most common adverse event in both groups was chest pain (248/2309 [10.7%] vs 118/1153 [10.2%]). INTERPRETATION: The use of an oral factor Xa inhibitor in patients stabilised after an acute coronary syndrome increases bleeding in a dose-dependent manner and might reduce major ischaemic outcomes. On the basis of these observations, a phase III study of low-dose rivaroxaban as adjunctive therapy in these patients is underway. FUNDING: Johnson & Johnson Pharmaceutical Research & Development and Bayer Healthcare AG.

Rivaroxaban. A novel, oral, direct factor Xa inhibitor in clinical development for the prevention and treatment of thromboembolic disorders.

Rivaroxaban (Xarelto) is a novel, oral, direct Factor Xa (FXa) inhibitor in late-stage development for the prevention and treatment of thromboembolic disorders. Rivaroxaban inhibits clot-associated and free FXa activity, and prothrombinase activity, and reduces thrombin generation. In animal models, rivaroxaban prevented venous and arterial thrombosis, and was effective at treating venous thrombosis. Rivaroxaban has high oral bioavailability, a rapid onset of action and predictable pharmacokinetics. In phase II studies, rivaroxaban was effective and well tolerated for the prevention of venous thromboembolism (VTE) after major orthopaedic surgery, and for the treatment of deep vein thrombosis. In a phase III study, rivaroxaban demonstrated significantly superior efficacy to enoxaparin for thromboprophylaxis after total knee arthroplasty, with similar low bleeding. Rivaroxaban is also being assessed for the treatment and secondary prevention of VTE, prevention of stroke in patients with atrial fibrillation and secondary prevention in patients with acute coronary syndrome. Rivaroxaban is a promising alternative to current pharmacological agents for thromboembolic disorders.

BAY 59-7939: an oral, direct factor Xa inhibitor for the prevention of venous thromboembolism in patients after total knee replacement. A phase II dose-ranging study.

BACKGROUND: BAY 59-7939, a novel, oral, direct factor Xa inhibitor, is in clinical development for the prevention of venous thromboembolism (VTE), a frequent complication following orthopaedic surgery. METHODS: In a multicenter, parallel-group, double-blind, double-dummy study, 621 patients undergoing elective total knee replacement were randomly assigned to oral BAY 59-7939 (2.5, 5, 10, 20, and 30 mg b.i.d., initiated 6-8 h postsurgery), or subcutaneous enoxaparin (30 mg b.i.d., initiated 12-24 h postsurgery). Treatment was continued until mandatory bilateral venography 5-9 days after surgery. The primary efficacy endpoint was a composite of any deep vein thrombosis (proximal and/or distal), confirmed non-fatal pulmonary embolism and all-cause mortality during treatment. The primary safety endpoint was major, postoperative bleeding during treatment. RESULTS: Of the 613 patients treated, 366 (59.7%) were evaluable for the primary efficacy analysis. The primary efficacy endpoint occurred in 31.7%, 40.4%, 23.3%, 35.1%, and 25.4% of patients receiving 2.5, 5, 10, 20 and 30 mg b.i.d. doses of BAY 59-7939, respectively (test for trend, P = 0.29), compared with 44.3% in the enoxaparin group. The frequency of major, postoperative bleeding increased with increasing doses of BAY 59-7939 (test for trend, P = 0.0007), with no significant difference between any dose group compared with enoxaparin. Bleeding endpoints were lower for the 2.5-10 mg b.i.d. doses compared with higher doses of BAY 59-7939. CONCLUSIONS: Oral administration of 2.5-10 mg b.i.d. of BAY 59-7939, early in the postoperative period, showed potential efficacy and an acceptable safety profile, similar to enoxaparin, for the prevention of VTE in patients undergoing elective total knee replacement.