Bivalirudin

Bivalirudin for injection is indicated for use as an anticoagulant for use in patients undergoing percutaneous coronary intervention (PCI) including patients with heparin-induced thrombocytopenia and heparin-induced thrombocytopenia and thrombosis syndrome. Bivalirudin for injection is a direct thrombin inhibitor indicated for use as an anticoagulant in patients undergoing percutaneous coronary intervention (PCI) including patients with heparin-induced thrombocytopenia (HIT) or heparin-induced thrombocytopenia and thrombosis syndrome (HITTS).( 1 )

For injection: 250 mg of bivalirudin as a lyophilized powder in a single dose vial for reconstitution. 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 . For injection: 250 mg of bivalirudin as a lyophilized powder in a single dose vial for reconstitution. ( 3 )

Bivalirudin is contraindicated in patients with:

• Active major bleeding;
• Hypersensitivity (e.g., anaphylaxis) to bivalirudin or its components [see Adverse Reactions (6.1) ] .
• Active major bleeding ( 4 )
• Hypersensitivity to bivalirudin or its components ( 4 )

• Bleeding Events: Bivalirudin increases the risk of bleeding. ( 5.1 , 6.1 , 12.2 )
• Acute Stent Thrombosis: Increased incidence of acute stent thrombosis in STEMI patients undergoing primary PCI. ( 2.1 , 5.2 )
• Thrombotic Risk with Coronary Artery Brachytherapy: An increased risk of thrombus formation, including fatal outcomes, in gamma brachytherapy. ( 5.3 )

5.1 Bleeding Events Bivalirudin increases the risk of bleeding [see Adverse Reactions ( 6.1 )] . An unexplained fall in blood pressure or hematocrit should lead to serious consideration of a hemorrhagic event and cessation of bivalirudin administration. Monitor patients receiving bivalirudin for signs and symptoms of bleeding. Monitor patients with disease states associated with an increased risk of bleeding more frequently for bleeding.

5.2 Acute Stent Thrombosis in Patients with STEMI Undergoing PCI Acute stent thrombosis (AST) (less than 4 hours) has been observed at a greater frequency in bivalirudin treated patients (1.2%, 36/2889) compared to heparin treated patients (0.2%, 6/2911) with STEMI undergoing primary PCI. Among patients who experienced an AST, one fatality (0.03%) occurred in a bivalirudin treated patient and one fatality (0.03%) in a heparin treated patient. These patients have been managed by Target Vessel Revascularization (TVR). Patients should remain for at least 24 hours in a facility capable of managing ischemic complications and should be carefully monitored following primary PCI for signs and symptoms consistent with myocardial ischemia.

5.3 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. If a decision is made to use bivalirudin during brachytherapy procedures, maintain meticulous catheter technique, with frequent aspiration and flushing, paying special attention to minimizing conditions of stasis within the catheter or vessels [see Adverse Reactions (6.3) ] .

Most common adverse reaction (>2%) was bleeding. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Sandoz Inc. at 1-800-525-8747 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

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%) patients undergoing PCI for treatment of unstable angina and randomized to bivalirudin experienced major bleeding events, which consisted of intracranial bleeding, retroperitoneal bleeding, and 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.

6.2 Immunogenicity As with all peptides, 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.

6.3 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.

In clinical trials in patients undergoing PCI/ percutaneous transluminal coronary angioplasty (PTCA), coadministration of bivalirudin with heparin, warfarin, thrombolytics, or GPIs was associated with increased risks of major bleeding events compared to patients not receiving these concomitant medications. Heparin, warfarin, thrombolytics, or GPIs: Increased major bleeding risk with concomitant use. ( 7 )

• Geriatric patients: Increased bleeding risk possible. ( 8.5 )
• Renal impairment: Reduce infusion dose and monitor ACT. ( 2.2 , 8.6 )

8.1 Pregnancy Risk Summary There are no data available 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 doses up to 1.6 times and 3.2 times the maximum recommended human dose (MRHD) of 15 mg/kg/day based on body surface area (BSA) during organogenesis, 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 (equivalent to 5.4 times the maximum recommended human dose based on body surface area) 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. There is no study covering the perinatal period because of the potential complications of drug-induced hemorrhage during delivery.

8.2 Lactation Risk Summary It is not known whether bivalirudin is present in human milk. No data are available on the effects on the breastfed child or on milk production. Bivalirudin was administered to lactating rats in reproduction studies (see Data) . The developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for bivalirudin and any potential adverse effects on the breastfed child from bivalirudin or from the underlying maternal condition. Data Animal Data Reproduction studies conducted in lactating female rats dosed subcutaneously daily with bivalirudin at doses up to 150 mg/kg/day (1.6 times the maximum recommended human dose, based on body surface area) from day 2 through day 20 of lactation revealed no adverse developmental outcomes to the pups.

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) ] . Reduce the infusion dose of bivalirudin and monitor the anticoagulant status more frequently in patients with renal impairment creatinine clearance less than 30 mL/min (by Cockcroft Gault equation) [see Dosage and Administration (2.2) ] .

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-Arg 3 -Pro 4 bond, resulting in recovery of thrombin active site functions. In in vitro studies, bivalirudin inhibited both soluble (free) and clot-bound thrombin, was not neutralized by products of the platelet release reaction, and prolonged the activated partial thromboplastin time (aPTT), thrombin time (TT), and prothrombin time (PT) of normal human plasma in a concentration-dependent manner. The clinical relevance of these findings is unknown.