Pharmacotherapeutic group: Antithrombotic agents, direct factor Xa inhibitors, ATC code: B01AF01
Mechanism of action
Rivaroxaban is a highly selective direct factor Xa inhibitor with oral bioavailability. Inhibition of factor Xa interrupts the intrinsic and extrinsic pathway of the blood coagulation cascade, inhibiting both thrombin formation and development of thrombi. Rivaroxaban does not inhibit thrombin (activated factor II) and no effects on platelets have been demonstrated.
Pharmacodynamic effects
Dose-dependent inhibition of factor Xa activity was observed in humans. Prothrombin time (PT) is influenced by rivaroxaban in a dose dependent way with a close correlation to plasma concentrations (r value equals 0.98) if Neoplastin is used for the assay. Other reagents would provide different results. The readout for PT is to be done in seconds, because the INR is only calibrated and validated for coumarins and cannot be used for any other anticoagulant. In patients undergoing major orthopaedic surgery, the 5/95 percentiles for PT (Neoplastin) 2 - 4 hours after tablet intake (i.e. at the time of maximum effect) ranged from 13 to 25 s (baseline values before surgery 12 to 15 s).
In a clinical pharmacology study on the reversal of rivaroxaban pharmacodynamics in healthy adult subjects (n=22), the effects of single doses (50 IU/kg) of two different types of PCCs, a 3-factor PCC (Factors II, IX and X) and a 4-factor PCC (Factors II, VII, IX and X) were assessed. The 3-factor PCC reduced mean Neoplastin PT values by approximately 1.0 second within 30 minutes, compared to reductions of approximately 3.5 seconds observed with the 4-factor PCC. In contrast, the 3-factor PCC had a greater and more rapid overall effect on reversing changes in endogenous thrombin generation than the 4-factor PCC (see section 4.9).
The activated partial thomboplastin time (aPTT) and HepTest are also prolonged dose-dependently; however, they are not recommended to assess the pharmacodynamic effect of rivaroxaban. There is no need for monitoring of coagulation parameters during treatment with rivaroxaban in clinical routine. However, if clinically indicated rivaroxaban levels can be measured by calibrated quantitative anti- factor Xa tests (see section 5.2).
Clinical efficacy and safety
Prevention of VTE in adult patients undergoing elective hip or knee replacement surgery
The rivaroxaban clinical programme was designed to demonstrate the efficacy of rivaroxaban for the prevention of VTE, i.e. proximal and distal deep vein thrombosis (DVT) and pulmonary embolism (PE) in patients undergoing major orthopaedic surgery of the lower limbs. Over 9,500 patients (7,050 in total hip replacement surgery and 2,531 in total knee replacement surgery) were studied in controlled randomised double-blind phase III clinical studies, the RECORD-programme. Rivaroxaban 10 mg once daily (od) started no sooner than 6 hours post-operatively was compared with enoxaparin 40 mg once daily started 12 hours pre-operatively.
In all three phase III studies (see table 4), rivaroxaban significantly reduced the rate of total VTE (any venographically detected or symptomatic DVT, non-fatal PE and death) and major VTE (proximal DVT, non-fatal PE and VTE-related death), the pre-specified primary and major secondary efficacy endpoints. Furthermore, in all three studies the rate of symptomatic VTE (symptomatic DVT, non- fatal PE, VTE-related death) was lower in rivaroxaban treated patients compared to patients treated with enoxaparin.
The main safety endpoint, major bleeding, showed comparable rates for patients treated with rivaroxaban 10 mg compared to enoxaparin 40 mg.
Table 4: Efficacy and safety results from phase III clinical studies
| | RECORD 1 | RECORD 2 | RECORD 3 |
| Study population | 4,541 patients undergoing total hip replacement surgery | 2,509 patients undergoing total hip replacement surgery | 2,531 patients undergoing total knee replacement surgery |
| Treatment dose and duration after surgery | Rivaroxaban 10 mg od 35 ± 4 days | Enoxaparin 40 mg od 35 ± 4 days | p | Rivaroxaban 10 mg od 35 ± 4 days | Enoxaparin 40 mg od 12 ± 2 days | p | Rivaroxaban 10 mg od 12 ± 2 days | Enoxaparian 40 mg od 12 ± 2 days | p |
| Total VTE | 18 (1.1%) | 58 (3.7%) | < 0.001 | 17 (2.0%) | 81 (9.3%) | < 0.001 | 79 (9.6%) | 166 (18.9%) | < 0.001 |
| Major VTE | 4 (0.2%) | 33 (2.0%) | < 0.001 | 6 (0.6%) | 49 (5.1%) | < 0.001 | 9 (1.0%) | 24 (2.6%) | 0.01 |
| Symptomatic VTE | 6 (0.4%) | 11 (0.7%) | 3 (0.4%) | 15 (1.7%) | 8 (1.0%) | 24 (2.7%) |
| Major bleedings | 6 (0.3%) | 2 (0.1%) | 1 (0.1%) | 1 (0.1%) | 7 (0.6%) | 6 (0.5%) |
The analysis of the pooled results of the phase III studies corroborated the data obtained in the individual studies regarding reduction of total VTE, major VTE and symptomatic VTE with rivaroxaban 10 mg once daily compared to enoxaparin 40 mg once daily.
In addition to the phase III RECORD programme, a post-authorisation, non-interventional, open-label cohort study (XAMOS) has been conducted in 17,413 patients undergoing major orthopaedic surgery of the hip or knee, to compare rivaroxaban with other pharmacological thromboprophylaxis (standard-of-care) under real-life setting. Symptomatic VTE occurred in 57 (0.6%) patients in the rivaroxaban group (n=8,778) and 88 (1.0%) of patients in the standard-of-care group (n=8,635; HR 0.63; 95% CI 0.43-0.91); safety population). Major bleeding occurred in 35 (0.4%) and 29 (0.3%) of patients in the rivaroxaban and standard-of-care groups (HR 1.10; 95% CI 0.67-1.80). Thus, the results were consistent with the results of the pivotal randomised studies.
Treatment of DVT, PE and prevention of recurrent DVT and PE
The rivaroxaban clinical programme was designed to demonstrate the efficacy of rivaroxaban in the initial and continued treatment of acute DVT and PE and prevention of recurrence.
Over 12,800 patients were studied in four randomised controlled phase III clinical studies (Einstein DVT, Einstein PE, Einstein Extension and Einstein Choice). and additionally a predefined pooled analysis of the Einstein DVT and Einstein PE studies was conducted. The overall combined treatment duration in all studies was up to 21 months.
In Einstein DVT 3,449 patients with acute DVT were studied for the treatment of DVT and the prevention of recurrent DVT and PE (patients who presented with symptomatic PE were excluded from this study). The treatment duration was for 3, 6 or 12 months depending on the clinical judgement of the investigator.
For the initial 3 week treatment of acute DVT 15 mg rivaroxaban was administered twice daily. This was followed by 20 mg rivaroxaban once daily.
In Einstein PE, 4,832 patients with acute PE were studied for the treatment of PE and the prevention of recurrent DVT and PE. The treatment duration was for 3, 6 or 12 months depending on the clinical judgement of the investigator.
For the initial treatment of acute PE 15 mg rivaroxaban was administered twice daily for three weeks. This was followed by 20 mg rivaroxaban once daily.
In both the Einstein DVT and the Einstein PE study, the comparator treatment regimen consisted of enoxaparin administered for at least 5 days in combination with vitamin K antagonist treatment until the PT/INR was in therapeutic range (≥ 2.0). Treatment was continued with a vitamin K antagonist dose-adjusted to maintain the PT/INR values within the therapeutic range of 2.0 to 3.0.
In Einstein Extension 1,197 patients with DVT or PE were studied for the prevention of recurrent DVT and PE. The treatment duration was for an additional 6 or 12 months in patients who had completed 6 to 12 months of treatment for venous thromboembolism depending on the clinical judgment of the investigator. Rivaroxaban 20 mg once daily was compared with placebo.
Einstein DVT, PE and Extension used the same pre-defined primary and secondary efficacy outcomes. The primary efficacy outcome was symptomatic recurrent VTE defined as the composite of recurrent DVT or fatal or non-fatal PE. The secondary efficacy outcome was defined as the composite of recurrent DVT, non-fatal PE and all-cause mortality.
In Einstein Choice, 3,396 patients with confirmed symptomatic DVT and/or PE who completed 6-12 months of anticoagulant treatment were studied for the prevention of fatal PE or non-fatal symptomatic recurrent DVT or PE. Patients with an indication for continued therapeutic-dosed anticoagulation were excluded from the study. The treatment duration was up to 12 months depending on the individual randomisation date (median: 351 days). Rivaroxaban 20 mg once daily and rivaroxaban 10 mg once daily were compared with 100 mg acetylsalicylic acid once daily.
The primary efficacy outcome was symptomatic recurrent VTE defined as the composite of recurrent DVT or fatal or non-fatal PE.
In the Einstein DVT study (see Table 5) rivaroxaban was demonstrated to be non-inferior to enoxaparin/VKA for the primary efficacy outcome (p < 0.0001 (test for non-inferiority); Hazard Ratio (HR): 0.680 (0.443 - 1.042), p=0.076 (test for superiority)). The prespecified net clinical benefit (primary efficacy outcome plus major bleeding events) was reported with a HR of 0.67 ((95% CI: 0.47 - 0.95), nominal p value p=0.027) in favour of rivaroxaban. INR values were within the therapeutic range a mean of 60.3% of the time for the mean treatment duration of 189 days, and 55.4%, 60.1%, and 62.8% of the time in the 3-, 6-, and 12-month intended treatment duration groups, respectively. In the enoxaparin/VKA group, there was no clear relation between the level of mean centre TTR (Time in Target INR Range of 2.0 – 3.0) in the equally sized tertiles and the incidence of the recurrent VTE (P=0.932 for interaction). Within the highest tertile according to centre, the HR with rivaroxaban versus warfarin was 0.69 (95% CI: 0.35 - 1.35).
The incidence rates for the primary safety outcome (major or clinically relevant non-major bleeding events) as well as the secondary safety outcome (major bleeding events) were similar for both treatment groups.
Table 5: Efficacy and safety results from phase III Einstein DVT
| Study population | 3,449 patients with symptomatic acute deep vein thrombosis |
| Treatment dose and duration | Rivaroxaban a) 3, 6 or 12 months N=1,731 | Enoxaparin/VKAb) 3, 6 or 12 months N=1,718 |
| Symptomatic recurrent VTE* | 36 (2.1%) | 51 (3.0%) |
| Symptomatic recurrent PE | 20 (1.2%) | 18 (1.0%) |
| Symptomatic recurrent DVT | 14 (0.8%) | 28 (1.6%) |
| Symptomatic PE and DVT | 1 (0.1%) | 0 |
| Fatal PE/death where PE cannot be ruled out | 4 (0.2%) | 6 (0.3%) |
| Major or clinically relevant non-major bleeding | 139 (8.1%) | 138 (8.1%) |
| Major bleeding events | 14 (0.8%) | 20 (1.2%) |
a) Rivaroxaban 15 mg twice daily for 3 weeks followed by 20 mg once daily
b) Enoxaparin for at least 5 days, overlapped with and followed by VKA
* p < 0.0001 (non-inferiority to a prespecified HR of 2.0); HR: 0.680 (0.443 - 1.042), p=0.076 (superiority)
In the Einstein PE study (see Table 6) rivaroxaban was demonstrated to be non-inferior to enoxaparin/VKA for the primary efficacy outcome (p=0.0026 (test for non-inferiority); HR: 1.123 (0.749 – 1.684)). The prespecified net clinical benefit (primary efficacy outcome plus major bleeding events) was reported with a HR of 0.849 ((95% CI: 0.633 - 1.139), nominal p value p= 0.275). INR values were within the therapeutic range a mean of 63% of the time for the mean treatment duration of 215 days, and 57%, 62%, and 65% of the time in the 3-, 6-, and 12-month intended treatment duration groups, respectively. In the enoxaparin/VKA group, there was no clear relation between the level of mean centre TTR (Time in Target INR Range of 2.0 – 3.0) in the equally sized tertiles and the incidence of the recurrent VTE (p=0.082 for interaction). Within the highest tertile according to centre, the HR with rivaroxaban versus warfarin was 0.642 (95% CI: 0.277 - 1.484).
The incidence rates for the primary safety outcome (major or clinically relevant non-major bleeding events) were slightly lower in the rivaroxaban treatment group (10.3% (249/2412)) than in the enoxaparin/VKA treatment group (11.4% (274/2405)). The incidence of the secondary safety outcome (major bleeding events) was lower in the rivaroxaban group (1.1% (26/2412)) than in the enoxaparin/VKA group (2.2% (52/2405)) with a HR 0.493 (95% CI: 0.308 - 0.789).
Table 6: Efficacy and safety results from phase III Einstein PE
| Study population | 4,832 patients with an acute symptomatic PE |
| Treatment dose and duration | Rivaroxaban a) 3, 6 or 12 months N=2,419 | Enoxaparin/VKAb) 3, 6 or 12 months N=2,413 |
| Symptomatic recurrent VTE* | 50 (2.1%) | 44 (1.8%) |
| Symptomatic recurrent PE | 23 (1.0%) | 20 (0.8%) |
| Symptomatic recurrent DVT | 18 (0.7%) | 17 (0.7%) |
| Symptomatic PE and DVT | 0 | 2 (<0.1%) |
| Fatal PE/death where PE cannot be ruled out | 11 (0.5%) | 7 (0.3%) |
| Major or clinically relevant non-major bleeding | 249 (10.3%) | 274 (11.4%) |
| Major bleeding events | 26 (1.1%) | 52 (2.2%) |
a) Rivaroxaban 15 mg twice daily for 3 weeks followed by 20 mg once daily
b) Enoxaparin for at least 5 days, overlapped with and followed by VKA
* p < 0.0026 (non-inferiority to a prespecified HR of 2.0); HR: 1.123 (0.749 – 1.684)
A prespecified pooled analysis of the outcome of the Einstein DVT and PE studies was conducted (see Table 7).
Table 7: Efficacy and safety results from pooled analysis of phase III Einstein DVT and Einstein PE
| Study population | 8,281 patients with an acute symptomatic DVT or PE |
| Treatment dose and duration | Rivaroxaban a) 3, 6 or 12 months N=4,150 | Enoxaparin/VKAb) 3, 6 or 12 months N=4,131 |
| Symptomatic recurrent VTE* | 86 (2.1%) | 95 (2.3%) |
| Symptomatic recurrent PE | 43 (1.0%) | 38 (0.9%) |
| Symptomatic recurrent DVT | 32 (0.8%) | 45 (1.1%) |
| Symptomatic PE and DVT | 1 (<0.1%) | 2 (<0.1%) |
| Fatal PE/death where PE cannot be ruled out | 15 (0.4%) | 13 (0.3%) |
| Major or clinically relevant non-major bleeding | 388 (9.4%) | 412 (10.0%) |
| Major bleeding events | 40 (1.0%) | 72 (1.7%) |
a) Rivaroxaban 15 mg twice daily for 3 weeks followed by 20 mg once daily
b) Enoxaparin for at least 5 days, overlapped with and followed by VKA
* p < 0.0001 (non-inferiority to a prespecified HR of 1.75); HR: 0.886 (0.661 – 1.186)
The prespecified net clinical benefit (primary efficacy outcome plus major bleeding events) of the pooled analysis was reported with a HR of 0.771 ((95% CI: 0.614 – 0.967), nominal p value p = 0.0244).
In the Einstein Extension study (see Table 8) rivaroxaban was superior to placebo for the primary and secondary efficacy outcomes. For the primary safety outcome (major bleeding events) there was a non-significant numerically higher incidence rate for patients treated with rivaroxaban 20 mg once daily compared to placebo. The secondary safety outcome (major or clinically relevant non-major bleeding events) showed higher rates for patients treated with rivaroxaban 20 mg once daily compared to placebo.
Table 8: Efficacy and safety results from phase III Einstein Extension
| Study population | 1,197 patients continued treatment and prevention of recurrent venous thromboembolism |
| Treatment dose and duration | Rivaroxaban a) 6 or 12 months N=602 | Placebo 6 or 12 months N=594 |
| Symptomatic recurrent VTE* | 8 (1.3%) | 42 (7.1%) |
| Symptomatic recurrent PE | 2 (0.3%) | 13 (2.2%) |
| Symptomatic recurrent DVT | 5 (0.8%) | 31 (5.2%) |
| Fatal PE/death where PE cannot be ruled out | 1 (0.2%) | 1 (0.2%) |
| Major bleeding events | 4 (0.7%) | 0 (0.0%) |
| Clinically relevant non-major bleeding | 32 (5.4%) | 7 (1.2%) |
a) Rivaroxaban 20 mg once daily
* p < 0.0001 (superiority), HR: 0.185 (0.087 - 0.393)
In the Einstein Choice study (Table 9) rivaroxaban 20 mg and 10 mg were both superior to 100 mg acetylsalicylic acid for the primary efficacy outcome. The principal safety outcome (major bleeding events) was similar for patients treated with rivaroxaban 20 mg and 10 mg once daily compared to 100 mg acetylsalicylic acid.
Table 9: Efficacy and safety results from phase III Einstein Choice
| Study population | 3,396 patients continued prevention of recurrent venous thromboembolism |
| Treatment dose | Rivaroxaban 20 mg once daily N=1,107 | Rivaroxaban 10 mg once daily N=1,127 | ASA 100 mg once daily N=1,131 |
| Treatment duration median [interquartile range] | 349 [189-362] days | 353 [190-362] days | 350 [186-362] days |
| Symptomatic recurrent VTE | 17 (1.5%)* | 13 (1.2%)** | 50 (4.4%) |
| Symptomatic recurrent PE | 6 (0.5%) | 6 (0.5%) | 19 (1.7%) |
| Symptomatic recurrent DVT | 9 (0.8%) | 8 (0.7%) | 30 (2.7%) |
| Fatal PE/death where PE cannot be ruled out | 2 (0.2%) | 0 | 2 (0.2%) |
| Symptomatic recurrent VTE, MI, stroke, or non-CNS systemic embolism | 19 (1.7%) | 18 (1.6%) | 56 (5.0%) |
| Major bleeding events | 6 (0.5%) | 5 (0.4%) | 3 (0.3%) |
| Clinically relevant non-major bleeding | 30 (2.7) | 22 (2.0) | 20 (1.8) |
| Symptomatic recurrent VTE or major bleeding (net clinical benefit) | 23 (2.1%)+ | 17 (1.5%)++ | 53 (4.7%) |
* p<0.001(superiority) rivaroxaban 20 mg od vs ASA 100 mg od; HR=0.34 (0.20–0.59)
** p<0.001 (superiority) rivaroxaban 10 mg od vs ASA 100 mg od; HR=0.26 (0.14–0.47)
+ Rivaroxaban 20 mg od vs ASA 100 mg od; HR=0.44 (0.27–0.71), p=0.0009 (nominal)
++ Rivaroxaban 10 mg od vs ASA 100 mg od; HR=0.32 (0.18–0.55), p<0.0001 (nominal)
In addition to the phase III EINSTEIN programme, a prospective, non-interventional, open-label cohort study (XALIA) with central outcome adjudication including recurrent VTE, major bleeding and death has been conducted. 5,142 patients with acute DVT were enrolled to investigate the long-term safety of rivaroxaban compared with standard-of-care anticoagulation therapy in clinical practice. Rates of major bleeding, recurrent VTE and all-cause mortality for rivaroxaban were 0.7%, 1.4% and 0.5%, respectively. There were differences in patient baseline characteristics including age, cancer and renal impairment. A pre-specified propensity score stratified analysis was used to adjust for measured baseline differences but residual confounding may, in spite of this, influence the results. Adjusted HRs comparing rivaroxaban and standard-of-care for major bleeding, recurrent VTE and all-cause mortality were 0.77 (95% CI 0.40 - 1.50), 0.91 (95% CI 0.54 - 1.54) and 0.51 (95% CI 0.24 - 1.07), respectively.
These results in clinical practice are consistent with the established safety profile in this indication.
In a post-authorisation, non-interventional study, in more than 40,000 patients without a history of cancer from four countries, rivaroxaban was prescribed for the treatment or prevention of DVT and PE. The event rates per 100 patient-years for symptomatic/clinically apparent TE/thromboembolic events leading to hospitalisation ranged from 0.64 (95% CI 0.40 - 0.97) in the UK to 2.30 (95% CI 2.11 - 2.51) for Germany. Bleeding resulting in hospitalisation occurred at event rates per 100 patient-years of 0.31 (95% CI 0.23 - 0.42) for intracranial bleeding, 0.89 (95% CI 0.67 - 1.17) for gastrointestinal bleeding, 0.44 (95% CI 0.26 - 0.74) for urogenital bleeding and 0.41 (95% CI 0.31 - 0.54) for other bleeding.
Patients with high risk triple positive antiphospholipid syndrome
In an investigator sponsored, randomised open-label multicentre study with blinded endpoint adjudication, rivaroxaban was compared to warfarin in patients with a history of thrombosis, diagnosed with antiphospholipid syndrome and at high risk for thromboembolic events (positive for all 3 antiphospholipid tests: lupus anticoagulant, anticardiolipin antibodies, and anti-beta 2-glycoprotein I antibodies). The study was terminated prematurely after the enrolment of 120 patients due to an excess of events among patients in the rivaroxaban arm. Mean follow-up was 569 days. 59 patients were randomised to rivaroxaban 20 mg (15 mg for patients with creatinine clearance (CrCl) < 50 mL/min) and 61 to warfarin (INR 2.0-3.0). Thromboembolic events occurred in 12% of patients randomised to rivaroxaban (4 ischaemic strokes and 3 myocardial infarctions). No events were reported in patients randomised to warfarin. Major bleeding occurred in 4 patients (7%) of the rivaroxaban group and 2 patients (3%) of the warfarin group.
Paediatric population
The European Medicines Agency has waived the obligation to submit the results of studies with Rivaroxaban in all subsets of the paediatric population in the prevention of thromboembolic events (see section 4.2 for information on paediatric use).