2.1 Recommended Dosage

The recommended dose of Bivalirudin Injection is an intravenous bolus dose of 0.75 mg/kg, followed immediately by a maintenance infusion of 1.75 mg/kg/h for the duration of the procedure. Five minutes after the bolus dose has been administered, assess activated clotting time (ACT) to determine if an additional bolus of 0.3 mg/kg is needed.

Consider extending duration of infusion following PCI at 1.75 mg/kg/h for up to 4 hours post- procedure in patients with ST segment elevation MI (STEMI).

2.2 Dose Adjustment in Renal Impairment

Bolus Dose:

No reduction in the bolus dose is needed for any degree of renal impairment. 

Maintenance Infusion:

In patients with creatinine clearance less than 30 mL/min (by Cockcroft Gault equation), reduce the infusion rate to 1 mg/kg/h.

In patients on hemodialysis, reduce the infusion rate to 0.25 mg/kg/h [see Use in Specific Populations (8.6), Clinical Pharmacology (12.3)].

2.3 Instructions for Administration

Bivalirudin Injection is a ready-to-use-sterile solution for intravenous use only.

Inspection of Container

Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit.

Once removed from the refrigerator, Bivalirudin Injection may be stored at room temperature 20º to 25°C (68º to 77°F) for up to 72 hours [see How Supplied Storage and Handling (16.2)].  Discard any unused portion.

Drug Compatibilities

No incompatibilities have been observed with administration sets.

Do not administer the drugs listed in Table 1 in the same intravenous line with Bivalirudin Injection.

Table 1. Drugs Not for Administration in the Same Intravenous Line with Bivalirudin Injection

5.1 Bleeding Events

Bivalirudin increases the risk of bleeding [see Adverse Reactions (6.1)]. Bivalirudin’s anticoagulant effect subsides approximately one hour after discontinuation [see Clinical Pharmacology (12.2)].

5.2 Thrombotic Risk with Coronary Artery Brachytherapy

An increased risk of thrombus formation, including fatal outcomes, has been associated with the use of bivalirudin in gamma brachytherapy [see Adverse Reactions (6.2)].

6.1 Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.

In the BAT trials, 79 of the 2161 (3.7%) of subjects undergoing PCI for treatment of unstable angina and randomized to bivalirudin experienced intracranial bleeding, retroperitoneal bleeding, clinically overt bleeding with a decrease in hemoglobin greater than 3 g/dL or leading to a transfusion of greater than 2 units of blood.

Immunogenicity/Re-Exposure

As with all therapeutic proteins, there is potential for immunogenicity. The detection of antibody formation is highly dependent on the sensitivity and specificity of the assay. Additionally, the observed incidence of antibody (including neutralizing antibody) positivity in an assay may be influenced by several factors including assay methodology, sample handling, timing of sample collection, concomitant medications, and underlying disease. For these reasons, comparison of the incidence of antibodies to bivalirudin in the studies described below with the incidence of antibodies in other studies or to other products may be misleading.

In in vitro studies, bivalirudin exhibited no platelet aggregation response against sera from patients with a history of HIT/HITTS.

Among 494 subjects who received bivalirudin in clinical trials and were tested for antibodies, 2 subjects had treatment-emergent positive bivalirudin antibody tests. Neither subject demonstrated clinical evidence of allergic or anaphylactic reactions and repeat testing was not performed. Nine additional patients who had initial positive tests were negative on repeat testing.

6.2 Postmarketing Experience

Because postmarketing adverse reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.

The following adverse reactions have been identified during post-approval use of bivalirudin: fatal bleeding; hypersensitivity and allergic reactions including reports of anaphylaxis; lack of anticoagulant effect; thrombus formation during PCI with and without intracoronary brachytherapy, including reports of fatal outcomes; pulmonary hemorrhage; cardiac tamponade; and INR increased.

8.1 Pregnancy

Risk Summary

There are no available data on use of bivalirudin in pregnant women to inform a drug-associated risk of adverse developmental outcomes. Reproduction studies in rats and rabbits administered subcutaneously (SC) doses up to 1.6 times and 3.2 times the maximum recommended human dose (MRHD) based on body surface area (BSA), respectively, revealed no evidence of fetal harm.

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

Data

Animal Data

Reproductive studies have been performed in rats at subcutaneous doses up to 150 mg/kg/day, (1.6 times the maximum recommended human dose based on body surface area) and rabbits at subcutaneous doses up to 150 mg/kg/day (3.2 times the maximum recommended human dose based on body surface area). These studies revealed no harm to the fetus attributable to bivalirudin.

At 500 mg/kg/day subcutaneously, litter sizes and live fetuses in rats were reduced. Fetal skeletal variations were also noted. Some of these changes could be attributed to maternal toxicity observed at high doses.

8.2 Lactation

Risk Summary

It is not known whether bivalirudin is present in human milk. No data are available on the effects of bivalirudin on the breastfed child or on milk production.

8.4 Pediatric Use

The safety and effectiveness of bivalirudin in pediatric patients have not been established.

8.5 Geriatric Use

In studies of patients undergoing PCI, 44% were ≥65 years of age and 12% of patients were ≥75 years old. Elderly patients experienced more bleeding events than younger patients.

8.6 Renal Impairment

The disposition of bivalirudin was studied in PTCA patients with mild, moderate and severe renal impairment. The clearance of bivalirudin was reduced approximately 21% in patients with moderate and severe renal impairment and was reduced approximately 70% in dialysis- dependent patients [see Clinical Pharmacology (12.3)]. The infusion dose of Bivalirudin Injection may need to be reduced, and anticoagulant status monitored in patients with renal impairment [see Dosage and Administration (2.2)].

12.1 Mechanism of Action

Bivalirudin directly inhibits thrombin by specifically binding both to the catalytic site and to the anion-binding exosite of circulating and clot-bound thrombin. Thrombin is a serine proteinase that plays a central role in the thrombotic process, acting to cleave fibrinogen into fibrin monomers and to activate Factor XIII to Factor XIIIa, allowing fibrin to develop a covalently cross-linked framework which stabilizes the thrombus; thrombin also activates Factors V and VIII, promoting further thrombin generation, and activates platelets, stimulating aggregation and granule release. The binding of bivalirudin to thrombin is reversible as thrombin slowly cleaves the bivalirudin-Arg3-Pro4 bond, resulting in recovery of thrombin active site functions.

12.2 Pharmacodynamics

In healthy volunteers and patients (with ≥70% vessel occlusion undergoing routine PTCA), bivalirudin exhibited dose- and concentration-dependent anticoagulant activity as evidenced by prolongation of the ACT, aPTT, PT, and TT. Intravenous administration of bivalirudin produces an immediate anticoagulant effect. Coagulation times return to baseline approximately 1 hour following cessation of bivalirudin administration. Bivalirudin also increases INR.

In 291 patients with ≥70% vessel occlusion undergoing routine PTCA, a positive correlation was observed between the dose of bivalirudin and the proportion of patients achieving ACT values of 300 sec or 350 sec. At a bivalirudin dose of 1 mg/kg intravenous bolus plus 2.5 mg/kg/h intravenous infusion (1.4 times higher than the approved dose of 1.75 mg/kg/h) for 4 hours, followed by 0.2 mg/kg/h, all patients reached maximal ACT values greater than 300 sec.

12.3 Pharmacokinetics

Bivalirudin exhibits linear pharmacokinetics following intravenous administration to patients undergoing PTCA. In these patients, a mean steady state bivalirudin concentration of 12.3 ± 1.7 mcg/mL is achieved following an intravenous bolus of 1 mg/kg and a 4-hour 2.5 mg/kg/h intravenous infusion.

Distribution

Bivalirudin does not bind to plasma proteins (except thrombin) or to red blood cells.  

Elimination

Bivalirudin has a half-life of 25 minutes in PTCA patients with normal renal function. The total body clearance of bivalirudin in PTCA patients with normal renal function is 3.4 mL/min/kg.

Metabolism

Bivalirudin is metabolized by proteolytic cleavage.

Excretion

Bivalirudin undergoes glomerular filtration. Tubular secretion and tubular reabsorption are also implicated in the excretion of bivalirudin, although the extent is unknown.

Specific Populations

Patients with Renal Impairment

Total body clearance was similar for PTCA patients with normal renal function and with mild renal impairment. Clearance was reduced by 21% in patients with moderate and severe renal impairment with a half-life of 34 and 57 minutes, respectively. In dialysis patients, clearance was reduced by 70%, with a half-life of 3.5 hours. Approximately 25% bivalirudin is cleared by hemodialysis.

13.1 Carcinogenesis, Mutagenesis, Impairment of Fertility

No long-term studies in animals have been performed to evaluate the carcinogenic potential of bivalirudin. Bivalirudin displayed no genotoxic potential in the in vitro bacterial cell reverse mutation assay (Ames test), the in vitro Chinese hamster ovary cell forward gene mutation test (CHO/HGPRT), the in vitro human lymphocyte chromosomal aberration assay, the in vitro rat hepatocyte unscheduled DNA synthesis (UDS) assay, and the in vitro rat micronucleus assay. Fertility and general reproductive performance in rats were unaffected by subcutaneous doses of bivalirudin up to 150 mg/kg/day, about 1.6 times the dose on a body surface area basis (mg/m2) of a 50 kg person given the maximum recommended dose of 15 mg/kg/day.

16.1 How Supplied

Bivalirudin Injection is supplied as a refrigerated, ready-to-use, clear to slightly opalescent, colorless to yellow, sterile solution in 250 mg/50 mL (5 mg/mL) single-dose, glass vials.  The single-dose vials are available as follows:

• NDC 70511-142-50: Carton containing 1 Bivalirudin Injection single-dose vial
• NDC 70511-142-84: Carton containing 10 Bivalirudin Injection single-dose vials

Each vial contains 250 mg of bivalirudin (equivalent to an average of 275 mg bivalirudin trifluoroacetate*).

*The range of bivalirudin trifluoroacetate is 270 to 280 mg based on a range of trifluoroacetic acid composition of 1.7 to 2.6 equivalents.

16.2 Storage

Store Bivalirudin Injection vials in the refrigerator between 2° to 8°C (36° to 46°F). Once removed from the refrigerator, Bivalirudin Injection may be stored at room temperature 20º to 25°C (68º to 77°F) for up to 72 hours) [see Dosage and Administration (2.3)]. Avoid excess heat.