Limitation of Use for NVAF

SAVAYSA should not be used in patients with CrCL > 95 mL/min because of an increased risk of ischemic stroke compared to warfarin [see Dosage and Administration (2.1), Warnings and Precautions (5.1) and Clinical Studies (14.1)].

Reversal of Anticoagulant Effect

There is no established way to reverse the anticoagulant effects of SAVAYSA, which can be expected to persist for approximately 24 hours after the last dose. The anticoagulant effect of SAVAYSA cannot be reliably monitored with standard laboratory testing. A specific reversal agent for edoxaban is not available. Hemodialysis does not significantly contribute to edoxaban clearance [see Clinical Pharmacology (12.3)]. Protamine sulfate, vitamin K, and tranexamic acid are not expected to reverse the anticoagulant activity of SAVAYSA. The use of prothrombin complex concentrates (PCC), or other procoagulant reversal agents such as activated prothrombin complex concentrate (APCC) or recombinant factor VIIa (rFVIIa) may be considered but has not been evaluated in clinical outcome studies [see Clinical Pharmacology (12.2)]. When PCCs are used, monitoring for anticoagulation effect of edoxaban using clotting test (PT, INR, or aPTT) or anti-FXa activity is not useful and is not recommended.

The ENGAGE AF-TIMI 48 Study

In the ENGAGE AF-TIMI 48 study, the median study drug exposure for the SAVAYSA and warfarin treatment groups was 2.5 years.

Bleeding was the most common reason for treatment discontinuation. Bleeding led to treatment discontinuation in 3.9% and 4.1% of patients in the SAVAYSA 60 mg and warfarin treatment groups, respectively.

In the overall population, major bleeding was lower in the SAVAYSA group compared to the warfarin group [HR 0.80 (0.70, 0.91), p < 0.001]. Table 6.1 shows major bleeding events (percentage of patients with at least one bleeding event, per year) for the indicated population (CrCL ≤ 95 mL/min).

The most common site of a major bleeding event was the gastrointestinal (GI) tract. Table 6.2 shows the number of and the rate at which patients experienced GI bleeding in the SAVAYSA 60 mg and warfarin treatment groups.

The rate of anemia-related adverse events was greater with SAVAYSA 60 mg than with warfarin (9.6% vs. 6.8%).

The comparative rates of major bleeding on SAVAYSA and warfarin were generally consistent among subgroups (see Figure 6.1). Bleeding rates appeared higher in both treatment arms (SAVAYSA and warfarin) in the following subgroups of patients: those receiving aspirin, those in the United States, those more than 75 years old and those with reduced renal function.

Other Adverse Reactions

The most common non-bleeding adverse reactions (≥ 1%) for SAVAYSA 60 mg versus warfarin were rash (4.2% vs. 4.1%), and abnormal liver function tests (4.8% vs. 4.6%), respectively.

Interstitial Lung Disease (ILD) was reported as a serious adverse event on treatment for SAVAYSA 60 mg and warfarin in 15 (0.2%) and 7 (0.1%) patients, respectively. Many of the cases in both treatment groups were confounded by the use of amiodarone, which has been associated with ILD, or by infectious pneumonia. In the overall study period, there were 5 and 0 fatal ILD cases in the SAVAYSA 60 mg and warfarin groups, respectively.

The Hokusai VTE Study

The safety of SAVAYSA in the treatment of VTE was assessed in the Hokusai VTE study. The duration of drug exposure for SAVAYSA was ≤ 6 months for 1561 (37.9%) of patients, > 6 months for 2557 (62.1%) of patients and 12 months for 1661 (40.3%) of patients.

Bleeding was the most common reason for treatment discontinuation and occurred in 1.4% and 1.4% of patients in the SAVAYSA and warfarin arms, respectively.

Bleeding in Patients with DVT and/or PE in the Hokusai VTE Study

The major safety outcome was Clinically Relevant Bleeding, defined as the composite of Major and Clinically Relevant Non-Major (CRNM) Bleeding that occurred during or within three days of stopping study treatment. The incidence of Clinically Relevant Bleeding was lower in SAVAYSA than warfarin [HR (95% CI): 0.81 (0.71, 0.94); p = 0.004].

Table 6.3 shows the number of patients experiencing bleeding events in the Hokusai VTE Study.

Patients with low body weight (≤ 60 kg), CrCL ≤ 50 mL/min, or concomitant use of select P-gp inhibitors were randomized to receive SAVAYSA 30 mg or warfarin. As compared to all patients who received SAVAYSA or warfarin in the 60 mg cohort, all patients who received SAVAYSA or warfarin in the 30 mg cohort (n = 1452, 17.6% of the entire study population) were older (60.1 vs 54.9 years), more frequently female (66.5% vs 37.7%), more frequently of Asian race (46.0% vs 15.6%) and had more co-morbidities (e.g., history of bleeding, hypertension, diabetes, cardiovascular disease, cancer). Clinically relevant bleeding events occurred in 58/733 (7.9%) of the SAVAYSA patients receiving 30 mg once daily and 92/719 (12.8%) of warfarin patients meeting the above criteria.

In the Hokusai VTE study, among all patients the most common bleeding adverse reactions (≥ 1%) are shown in Table 6.4.

Bleeding in Patients with VTE in the Hokusai VTE Cancer Study

The safety of SAVAYSA in patients with cancer and VTE was evaluated in the Hokusai VTE Cancer study [see Clinical Studies (14.2)]. The median duration of SAVAYSA exposure was 211 days (range, 2 to 423). The safety outcome was major bleeding that occurred during or within three days of stopping study treatment. The incidence of major bleeding was higher in the SAVAYSA arm than in the dalteparin arm [HR (95% CI): 2.00 (1.09, 3.66)].

Table 6.5 presents the bleeding results from the Hokusai VTE Cancer study.

In patients with GI cancer at randomization, major bleeding occurred in 13.2% (18/136) in the SAVAYSA group and 2.4% (3/125) in the dalteparin group. In patients without GI cancer at randomization, major bleeding occurred in 3.6% (14/386) in the SAVAYSA group and 3.3% (13/399) in the dalteparin group.

Treatment of NVAF

Based on clinical experience from the ENGAGE AF-TIMI 48 study, dose reduction in patients concomitantly receiving P-gp inhibitors resulted in edoxaban blood levels that were lower than in patients who were given the full dose. Consequently, no dose reduction is recommended for concomitant P-gp inhibitor use [see Dosage and Administration (2.1), Clinical Pharmacology (12.3), and Clinical Studies (14.1)].

Treatment of Deep Vein Thrombosis and Pulmonary Embolism

[see Clinical Studies (14.2)]

Risk Summary

Available data about SAVAYSA use in pregnant women are insufficient to determine whether there are drug-associated risks for adverse developmental outcomes. In animal developmental studies, no adverse developmental effects were seen when edoxaban was administered orally to pregnant rats and rabbits during organogenesis at up to 16-times and 8-times, respectively, the human exposure, when based on body surface area and AUC, respectively (see Data).

The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2-4% and 15-20%, respectively.

Clinical Considerations

Data

Risk Summary

There are no data on the presence of edoxaban in human milk, or its effects on the breastfeeding infant or on milk production. Edoxaban was present in rat milk. Because of the potential for serious adverse reactions in nursing infants, including hemorrhage, advise patients that breastfeeding is not recommended during treatment with SAVAYSA.

Cardiac Electrophysiology

In a thorough QT study in healthy men and women aged 19-45 years, no QTc interval prolongation was observed with edoxaban (90 mg and 180 mg).

Effect of PCCs on Pharmacodynamics of SAVAYSA

There is no systematic evaluation of bleeding reversal by 4-factor prothrombin complex concentrate (PCC) products in patients who have received SAVAYSA.

Effects of PCC (50 IU/kg) on the pharmacodynamics of edoxaban were studied in healthy subjects following a punch biopsy. Following administration of a single dose of edoxaban, endogenous thrombin potential (ETP) returned to pre-edoxaban baseline levels in 0.5 hours after the initiation of a 15-minute infusion of 50 IU/kg PCC, compared to more than 24 hours with placebo. Mean ETP levels continued to increase and exceeded pre-edoxaban baseline, reaching maximum elevations (~40% over pre-edoxaban levels) at 22 hours after initiating PCC dose, which was the last observation of ETP. The clinical relevance of this ETP increase is unknown.

Pharmacodynamic Interactions

Absorption

Following oral administration, peak plasma edoxaban concentrations are observed within 1-2 hours. Absolute bioavailability is 62%. Food does not affect total systemic exposure to edoxaban. SAVAYSA was administered with or without food in the ENGAGE AF-TIMI 48 and Hokusai VTE trials.

Administration of a crushed 60 mg tablet, either mixed into applesauce or suspended in water and given through a nasogastric tube, showed similar exposure compared to administration of an intact tablet.

Distribution

Disposition is biphasic. The steady-state volume of distribution (Vdss) is 107 (19.9) L [mean (SD)]. In vitro plasma protein binding is approximately 55%. There is no clinically relevant accumulation of edoxaban (accumulation ratio 1.14) with once daily dosing.

Steady-state concentrations are achieved within 3 days.

Elimination

Edoxaban is eliminated primarily as unchanged drug in the urine. Renal clearance (11 L/hour) accounts for approximately 50% of the total clearance of edoxaban (22 L/hour). Metabolism and biliary/intestinal excretion account for the remaining clearance. The terminal elimination half-life of edoxaban following oral administration is 10 to 14 hours.

Specific Populations

Drug Interactions

The ENGAGE AF-TIMI 48 Study

The ENGAGE AF-TIMI 48 (NCT00781391) study was a multi-national, double-blind, non-inferiority study comparing the efficacy and safety of two SAVAYSA treatment arms (60 mg and 30 mg) to warfarin (titrated to INR 2.0 to 3.0) in reducing the risk of stroke and systemic embolic events in patients with NVAF. The non-inferiority margin (degree of inferiority of SAVAYSA to warfarin that was to be ruled out) was set at 38%, reflecting the substantial effect of warfarin in reducing strokes. The primary analysis included both ischemic and hemorrhagic strokes.

To enter the study, patients had to have one or more of the following additional risk factors for stroke:

• a prior stroke (ischemic or unknown type), transient ischemic attack (TIA) or non-CNS systemic embolism, or
• 2 or more of the following risk factors:

  –

  age ≥ 75 years,

  –

  hypertension,

  –

  heart failure, or

  –

  diabetes mellitus

A total of 21,105 patients were randomized and followed for a median of 2.8 years and treated for a median of 2.5 years. Patients in the SAVAYSA treatment arms had their dose halved (60 mg halved to 30 mg or 30 mg halved to 15 mg) if one or more of the following clinical factors were present: CrCL ≤ 50 mL/min, low body weight (≤ 60 kg) or concomitant use of specific P-gp inhibitors (verapamil, quinidine, dronedarone). Patients on antiretroviral therapy (ritonavir, nelfinavir, indinavir, saquinavir) as well as cyclosporine were excluded from the study. Approximately 25% of patients in all treatment groups received a reduced dose at baseline, and an additional 7% were dose-reduced during the study. The most common reason for dose reduction was a CrCL ≤ 50 mL/min at randomization (19% of patients).

Patients were well balanced with respect to demographic and baseline characteristics. The percentages of patients age ≥ 75 years and ≥ 80 years were approximately 40% and 17%, respectively. The majority of patients were Caucasian (81%) and male (62%). Approximately 40% of patients had not taken a Vitamin K Antagonist (VKA) (i.e., never took a VKA or had not taken a VKA for more than 2 months).

The mean patient body weight was 84 kg (185 lbs) and 10% of patients had a body weight of ≤ 60 kg. Concomitant diseases of patients in this study included hypertension (94%), congestive heart failure (58%), and prior stroke or transient ischemic attack (28%). At baseline, approximately 30% of patients were on aspirin and approximately 2% of patients were taking a thienopyridine.

Patients randomized to the warfarin arm achieved a mean TTR (time in therapeutic range, INR 2.0 to 3.0) of 65% during the course of the study.

The primary endpoint of the study was the occurrence of first stroke (either ischemic or hemorrhagic) or of a systemic embolic event (SEE) that occurred during treatment or within 3 days from the last dose taken. In the overall results of the study, shown in Table 14.1, both treatment arms of SAVAYSA were non-inferior to warfarin for the primary efficacy endpoint of stroke or SEE. However, the 30 mg (15 mg dose-reduced) treatment arm was numerically less effective than warfarin for the primary endpoint, and was also markedly inferior in reducing the rate of ischemic stroke. Based on the planned superiority analysis (ITT, which required p < 0.01 for success), statistical superiority of the 60 mg (30 mg dose-reduced) treatment arm compared to warfarin was not established in the total study population, but there was a favorable trend [HR (99% CI): 0.87 (0.71, 1.07)].

Figure 14.1 is a plot of the time from randomization to the occurrence of the first primary endpoint in all patients randomized to 60 mg SAVAYSA or warfarin.

The incidence rate of the primary endpoint of stroke or SEE in patients (N = 1776) treated with the 30 mg reduced dose of SAVAYSA because of a CrCL level ≤ 50 mL/min, low body weight ≤ 60 kg, or the concomitant use of a P-gp inhibitor drug, was 1.79% per year. Patients with any of these characteristics who were randomized to receive warfarin had an incidence rate of the primary endpoint of 2.21% per year [HR (95% CI): 0.81 (0.58, 1.13)].

In all randomized patients during the overall study period, the rates of CV death with SAVAYSA and warfarin were 2.74% per year vs. 3.17% per year, respectively [HR (95% CI): 0.86 (0.77, 0.97)].

The results in the ENGAGE AF-TIMI 48 study for the primary efficacy endpoint for most major subgroups are displayed in Figure 14.2.

The results of the ENGAGE AF-TIMI 48 study show a strong relationship between the blood levels of edoxaban and its effectiveness in reducing the rate of ischemic stroke. There was a 64% increase in the ischemic stroke rate in patients in the 30 mg treatment arm (including patients with dose reduced to 15 mg) compared to the 60 mg treatment arm (including patients with dose reduced to 30 mg). Approximately half of the SAVAYSA dose is eliminated by the kidney, and edoxaban blood levels are lower in patients with better renal function, averaging about 30% less in patients with CrCL of > 80 mL/min, and 40% less in patients with CrCL > 95 mL/min when compared to patients with a CrCL of > 50 to ≤ 80 mL/min. Given the clear relationship of dose and blood levels to effectiveness in the ENGAGE AF-TIMI 48 study, it could be anticipated that patients with better renal function would show a smaller effect of SAVAYSA compared to warfarin than would patients with mildly impaired renal function, and this was in fact observed.

Table 14.2 shows the results for the study primary efficacy endpoint of first stroke or SEE as well as the effects on ischemic and hemorrhagic stroke in the pre-randomization CrCL subgroups for SAVAYSA 60 mg (including 30 mg dose-reduced) and warfarin. There was a decreased rate of ischemic stroke with SAVAYSA 60 mg compared to warfarin in patients with CrCL > 50 to ≤ 80 mL/min [HR (95% CI): 0.63 (0.44, 0.89)]. In patients with CrCL > 80 to ≤ 95 mL/min the results for ischemic stroke slightly favor warfarin with a confidence interval that crosses 1.0 [HR (95% CI): 1.11 (0.58, 2.12)]. The rate of ischemic stroke was higher relative to warfarin in the patients with CrCL > 95 mL/min [HR (95% CI): 2.16 (1.17, 3.97)]. Pharmacokinetic data indicate that patients with CrCL > 95 mL/min had lower plasma edoxaban levels, along with a lower rate of bleeding relative to warfarin than patients with CrCL ≤ 95 mL/min. Consequently, SAVAYSA should not be used in patients with CrCL > 95 mL/min [see Dosage and Administration (2.1), Warnings and Precautions (5.1), Adverse Reactions (6.1), and Clinical Pharmacology (12.3)].

In patients with CrCL ≤ 95 mL/min, the SAVAYSA 60 mg (30 mg dose-reduced) treatment arm reduced the risk of stroke or SEE when compared to warfarin [HR (95% CI): 0.68 (0.55, 0.84)].

In the indicated population (CrCL ≤ 95 mL/min), during the overall study period, the rates of CV death with SAVAYSA and warfarin were 2.95% per year vs. 3.59% per year, respectively [HR (95% CI): 0.82 (0.72, 0.93)].

Transition to Other Anticoagulants in the ENGAGE AF-TIMI 48 Study

In the ENGAGE AF-TIMI 48 study, the schemes for transitioning from study medication to open-label warfarin at the end of study were associated with similar rates of stroke and systemic embolism in the SAVAYSA 60 mg and warfarin groups [see Dosage and Administration (2.4)]. In the SAVAYSA 60 mg group 7 (0.2%) of 4529 patients had a stroke or SEE compared to 7 (0.2%) of 4506 patients in the warfarin arm.

The Hokusai VTE Study

SAVAYSA for the treatment of patients with deep vein thrombosis (DVT) and pulmonary embolism (PE) was studied in a multi-national, double-blind study (Hokusai VTE) (NCT00986154) which compared the efficacy and safety of SAVAYSA 60 mg orally once daily to warfarin (titrated to INR 2.0 to 3.0) in patients with acute symptomatic venous thromboembolism (VTE) (DVT or PE with or without DVT). All patients had VTE confirmed by appropriate diagnostic imaging at baseline and received initial heparin therapy with low molecular weight heparin (LMWH) or unfractionated heparin for at least 5 days [median LMWH/heparin treatment in the SAVAYSA 60 mg group was 7 days, and in the warfarin group it was 8.0 days] and until INR (sham or real) was ≥ 2.0 on two measurements. Blinded drug treatment in the warfarin arm was started concurrently with initial heparin therapy and in the SAVAYSA arm after discontinuation of initial heparin. Patients randomized to SAVAYSA received 30 mg once daily if they met one or more of the following criteria: CrCL 30 to 50 mL/min, body weight ≤ 60 kg, or concomitant use of specific P-gp inhibitors (verapamil and quinidine or the short-term concomitant administration of azithromycin, clarithromycin, erythromycin, oral itraconazole or oral ketoconazole). The edoxaban dosage regimen was to be returned to the regular dosage of 60 mg once daily at any time the subject is not taking the concomitant medication provided no other criteria for dose reduction are met. Other P-gp inhibitors were not permitted in the study. Patients on antiretroviral therapy (ritonavir, nelfinavir, indinavir, saquinavir) as well as cyclosporine were excluded from the Hokusai VTE study. The concomitant use of these drugs with SAVAYSA has not been studied in patients. The treatment duration was from 3 months up to 12 months, determined by investigator based on patient clinical features. Patients were excluded if they required thrombectomy, insertion of a caval filter, use of a fibrinolytic agent, or use of other P-gp inhibitors, had a creatinine clearance < 30 mL/min, significant liver disease, or active bleeding. The primary efficacy outcome was symptomatic VTE, defined as the composite of recurrent DVT, new non-fatal symptomatic PE, and fatal PE during the 12-month study period.

A total of 8292 patients were randomized to receive SAVAYSA or warfarin and were followed for a mean treatment duration of 252 days for SAVAYSA and 250 days for warfarin. The mean age was approximately 56 years. The population was 57% male, 70% Caucasian, 21% Asian, and about 4% Black. The presenting diagnosis was PE (with or without DVT) in 40.7% and DVT only in 59.3% of patients. At baseline, 27.6% of patients had temporary risk factors only (e.g., trauma, surgery, immobilization, estrogen therapy). Overall 9.4% had a history of cancer, 17.3% of the patients had an age ≥ 75 years and/or a body weight ≤ 50 kg, and/or a CrCL < 50 mL/min, and 31.4% of patients had NT-ProBNP ≥ 500 pg/mL.

Aspirin was taken as on treatment concomitant antithrombotic medication by approximately 9% of patients in both groups.

In the warfarin group, the median TTR (time in therapeutic range, INR 2.0 to 3.0) was 65.6%.

A total of 8240 patients (n = 4118 for SAVAYSA and n = 4122 for warfarin) received study drug and were included in the modified intent-to-treat (mITT) population. SAVAYSA was demonstrated to be non-inferior to warfarin for the primary endpoint of recurrent VTE [HR (95% CI): 0.89 (0.70, 1.13)] (Table 14.3, Figure 14.3).

Figure 14.3: Kaplan-Meier Cumulative Event Rate Estimates for Adjudicated Recurrent VTE (mITT analysis – on treatment)

The Hokusai VTE Cancer Study

In the Hokusai VTE Cancer study (NCT02073682), 1050 patients were randomized to receive SAVAYSA 60 mg once daily [30 mg dose reduced per the dose adjustment regimen used in Engage AF-TIMI 48 and Hokusai VTE studies, (see The Hokusai VTE Study)] after at least 5 days of low-molecular-weight heparin treatment or dalteparin (200 IU/kg day 1-30; 150 IU/kg day 31 to the end of treatment). The treatment duration was for a minimum of 6 months and up to 12 months.

The efficacy of SAVAYSA was based upon the rate of recurrent VTE (mITT) during the overall study period. SAVAYSA was non-inferior to dalteparin for the rate of recurrent VTE. Recurrent VTE occurred in 7.9% (41/522) and 11.3% (59/524) of patients in the SAVAYSA and dalteparin groups, respectively [HR (95% CI): 0.71 (0.48, 1.06)].