factor IX

INDICATIONS AND USAGE REBINYN, Coagulation Factor IX (Recombinant), GlycoPEGylated, is a recombinant DNA-derived coagulation Factor IX concentrate indicated for use in adults and children with hemophilia B (congenital Factor IX deficiency) for: • On-demand treatment and control of bleeding episodes • Perioperative management of bleeding • Routine prophylaxis to reduce the frequency of bleeding episodes Limitations of Use : REBINYN is not indicated for immune tolerance induction in patients with hemophilia B. REBINYN, Coagulation Factor IX (Recombinant), GlycoPEGylated, is a recombinant DNA-derived coagulation Factor IX concentrate indicated for use in adults and children with hemophilia B (congenital Factor IX deficiency) for: • On-demand treatment and control of bleeding episodes • Perioperative management of bleeding • Routine prophylaxis to reduce the frequency of bleeding episodes Limitations of Use : REBINYN is not indicated for immune tolerance induction in patients with hemophilia B ( 1 ).

DOSAGE AND ADMINISTRATION For intravenous use after reconstitution only. For intravenous use after reconstitution only. On-demand treatment and control of bleeding episodes and perioperative management of bleeding: Adolescents/Adults (≥ 12 years of age): One international unit (IU) of IXINITY per kg body weight increases the circulating activity of factor IX by 0.98 IU/dL. ( 2.1 ) Children (< 12 years of age): One international (IU) of IXINITY per kg body weight increases the circulating activity of factor IX by 0.79 IU/dL. ( 2.1 ) Initial dose: Required factor IX units (IU) = body weight (kg) x desired factor IX increase (% of normal or IU/dL) x reciprocal of observed recovery (IU/kg per IU/dL). ( 2.1 ) The maintenance dose depends on the type of bleed or surgery, the intensity of the hemostatic challenge, and number of days until adequate wound healing is achieved. ( 2.1 ) Routine prophylaxis: Adolescents/Adults (≥ 12 years of age): 40 to 70 IU/kg twice weekly. ( 2.1 ) Children (< 12 years of age): 35 to 75 IU/kg twice weekly. Adjust the dosing regimen (dose or frequency) based on the patient’s clinical response. ( 2.1 ) 2.1 Dose Each vial of IXINITY has the recombinant factor IX (rFIX) potency in international units (IU) stated on the vial. Dosage and duration of treatment for factor IX products depend on the severity of the factor IX deficiency, the location and extent of bleeding, the patient’s clinical condition, age, and pharmacokinetic parameters of factor IX, such as incremental recovery and half-life. Initial Dose Adolescents/Adults ≥ 12 years of age): Calculate the initial dose of IXINITY based on the empirical finding that one international unit (IU) of IXINITY per kg body weight increases the circulating level of factor IX by 0.98 international units/dL (IU/dL) of plasma in adults and children ≥ 12 years of age. Children (< 12 years of age): Calculate the initial dose of IXINITY based on the empirical finding that one international unit (IU) of IXINITY per kg body weight increases the circulating level of factor IX by 0.79 international units/dL (IU/dL) of plasma in children < 12 years of age. Initial Dose = body weight (kg) x desired factor IX increase (% of normal or IU/dL) × reciprocal of observed recovery (IU/kg per IU/dL) Incremental Recovery in Previously Treated Patients (PTPs) Base calculation of the dose on the patient’s individual incremental recovery using serial factor IX activity assays, to account for the wide range of inter-individual differences in incremental recovery and the type of aPTT reagent used for the assay. Titrate the dose based on the patient’s clinical response and individual pharmacokinetics, in particular incremental recovery and half-life. Adolescents/Adults (≥ 12 years of age): For an incremental recovery of 0.98 IU/dL per IU/kg (0.98% of normal), calculate the dose as follows: Dose (IU) = body weight (kg) x desired factor IX increase (% of normal or IU/dL) × 1.02 dL/kg Examples (assuming patient’s baseline factor IX level is < 1% of normal): A peak of 70% is required in a 60 kg patient. The appropriate dose would be (60 kg × 70 IU/dL)/(0.98 IU/dL per IU/kg) = 4286 IU A dose of 4550 international units (IUs) of IXINITY administered to a 70 kg patient should be expected to result in a peak post-infusion factor IX increase of 4550 IU x (0.98 IU/dL per IU/kg)/(70 kg) = 64 IU/dL (approximately 64% of normal) Children (< 12 years of age): A lower recovery has been observed in pediatric patients (< 12 years, n=20). For an incremental recovery of 0.79 IU/dL per IU/kg (0.79% of normal), calculate the dose as follows: Dose (IU) = body weight (kg) x desired factor IX increase (% of normal or IU/dL) × 1.27 dL/kg Examples (assuming patient’s baseline factor IX level is < 1% of normal): A peak of 60% is required in a 20 kg patient. The appropriate dose would be (20 kg x 60 IU/dL)/(0.79 IU/dL per IU/kg) = 1519 IU A dose of 500 international units (IUs) of IXINITY administered to a 7 kg patient should be expected to result in a peak post-infusion factor IX increase of 500 IU x (0.79 IU/dL per IU/kg)/(7 kg) = 56 IU/dL (approximately 56% of normal) Monitor factor IX activity to ensure that the desired factor IX activity level has been achieved [see Warnings and Precautions (5.5) ]. Titrate doses using factor IX activity and pharmacokinetic parameters such as half-life and incremental recovery, as well as by taking the clinical situation into consideration, to adjust the dose and frequency of repeated infusions as appropriate. Factor IX activity measurements in the clinical laboratory may be affected by the type of activated partial thromboplastin time (aPTT) reagent or laboratory standard used [see Warnings and Precautions (5.5) ]. On-demand Treatment and Control of Bleeding Episodes and Perioperative Management of Bleeding Guides for dosing IXINITY in the on-demand treatment and control of bleeding episodes ( Table 1 ) and perioperative management ( Table 2 ) are provided in the tables below. Individual patients may vary in their response to factor IX and may demonstrate different levels of in vivo recovery and different half-lives. For surgical procedures, initiate treatment with IXINITY early enough pre-operatively to achieve and maintain the desired factor IX level before starting the procedure. Routine Prophylaxis For adolescents/ adults ≥ 12 years of age the recommended dose for previously treated patients (PTPs) is 40 to 70 IU/kg twice weekly. For children < 12 years of age the recommended dose for previously treated patients (PTPs) is 35 to 75 IU/kg twice weekly. Children (<12 years) have lower recovery, shorter half-life and higher clearance (based on per kg body weight) as compared to adolescents and adults. Adjust the dosing regimen (dose or frequency) based on the patient's clinical response. Adjust the dose based on the individual patient’s age, bleeding pattern, and physical activity. Table 1 Dosing for On-demand Treatment and Control of Bleeding Episodes Adapted from Srivastava et al. 2013 (1) . Type of Bleeding Episode Desired Peak Factor IX Level (% of normal or IU/dL) Dosing Interval (hours) Duration of therapy (days) Minor Early bleeds: uncomplicated hemarthroses and superficial muscle (except iliopsoas) with no neurovascular compromise, other soft tissue 30-60 24 1-3, until healing is achieved Moderate Hemarthrosis of longer duration, recurrent hemarthrosis, mucous membranes, deep lacerations, hematuria 40-60 24 2-7, until healing is achieved Major or Life Threatening Iliopsoas, deep muscle with neurovascular injury, substantial blood loss, CNS, pharyngeal, retropharyngeal, retroperitoneal 60-100 12-24 2-14, until healing is achieved Table 2 Dosing for Perioperative Management Adapted from Srivastava et al. 2013 (1) . Type of Surgery Desired Peak Factor IX Level (% of normal or IU/dL) Dosing Interval (hours) Duration of therapy (days) Minor (including uncomplicated dental extractions) Pre-op 50-80 Post-op 30-80 24 1-5, depending on type of procedure Major Pre-op 60-80 Post-op 40-60 30-50 20-40 8-24 1-3 4-6 7-14 2.2 Preparation and Reconstitution The procedures below are provided as general recommendations for the preparation and reconstitution of IXINITY. Before starting reconstitution and administration you will need the following items that are included in each kit of IXINITY: One (or more) vial(s) of IXINITY 250, 500, 1000, 1500, 2000, or 3000 IU powder One (or more) 10 mL syringe(s), pre-filled with 5 mL of Sterile Water for Injection (pre-filled syringe) with plunger rod attached One sterile vial adapter with filter In addition, you will need the following items that are not included in the kit: One sterile LUER-LOK™ syringe (administration syringe); additional or larger syringes may be required if pooling multiple vials Sterile alcohol swabs Sterile infusion set Sterile gauze pad Sterile bandage Always work on a clean surface and wash your hands before performing the following procedures: Use a

WARNINGS AND PRECAUTIONS • Hypersensitivity reactions, including anaphylaxis, have occurred. Should hypersensitivity reactions occur, discontinue REBINYN and administer appropriate treatment ( 5.1 ). • Neutralizing antibodies (inhibitors) to Factor IX have occurred following administration of REBINYN. Perform an assay that measures Factor IX inhibitor concentration if bleeding is not controlled with the recommended dose of REBINYN or if plasma Factor IX activity level fails to increase as expected (5.2 , 5.5 ). • The use of Factor IX- products has been associated with the development of thromboembolic complications ( 5.3 ). • Nephrotic syndrome has been reported following immune tolerance induction with Factor IX-containing products in hemophilia B patients with Factor IX inhibitors and a history of allergic reactions to Factor IX. ( 5.4 ) • Factor IX activity assay results may vary with the type of activated partial thromboplastin time reagent used ( 5.5 ). 5.1 Hypersensitivity Reactions Allergic-type hypersensitivity reactions, including anaphylaxis, have occurred with REBINYN. The product may contain traces of hamster proteins which in some patients may cause allergic reactions. Signs of allergic reactions, which can progress to anaphylaxis, may include angioedema, chest tightness, difficulty breathing, wheezing, urticaria, and itching. Observe patients for signs and symptoms of acute hypersensitivity reactions, particularly during the early phases of exposure to the product. Discontinue use of REBINYN if allergic- or anaphylactic - type reactions occur, and initiate appropriate treatment. 5.2 Inhibitors The formation of inhibitors (neutralizing antibodies) to Factor IX has occurred following REBINYN. If expected plasma factor IX activity levels are not attained, or if bleeding is not controlled as expected with the administered dose, perform an assay that measures Factor IX inhibitor concentration. Monitor all patients using clinical observations and laboratory tests for the development of inhibitors [ see Warnings and Precautions (5.5) ]. An association between the development of Factor IX inhibitors and allergic reactions has been reported. Evaluate patients experiencing allergic reactions for the presence of an inhibitor. Patients with Factor IX inhibitors may be at an increased risk of severe allergic reactions with subsequent exposure to Factor IX. 5.3 Thrombotic Events The use of Factor IX-containing products has been associated with thromboembolic complications. Due to the potential risk of thromboembolic complications, monitor patients for early signs of thrombotic and consumptive coagulopathy when administering this product to patients with liver disease, post-operatively, to newborn infants, or to patients at risk of thrombosis or disseminated intravascular coagulation (DIC). In each of these situations, the benefit of treatment with REBINYN should be weighed against the risk of these complications. 5.4 Nephrotic Syndrome Nephrotic syndrome has been reported following immune tolerance induction therapy with Factor IX products in hemophilia B patients with Factor IX inhibitors, often with a history of allergic reactions to Factor IX. The safety and efficacy of using REBINYN for immune tolerance induction have not been established. 5.5 Monitoring Laboratory Tests If monitoring of Factor IX activity is performed, use a chromogenic assay or selected one-stage clotting assay validated for use with REBINYN [ see Dosage and Administration ( 2 ) ]. The one-stage clotting assay results can be significantly affected by the type of activated partial thromboplastin time (aPTT) reagent used, which can result in over- or under-estimation of Factor IX activity. Avoid the use of silica-based reagents, as some may overestimate the activity of REBINYN. If a validated one-stage clotting or chromogenic assay is not available locally, then use of a reference laboratory is recommended. If bleeding is not controlled with the recommended dose of REBINYN, or if the expected Factor IX activity levels in plasma are not attained, then perform a Bethesda assay to determine if Factor IX inhibitors are present.

CONTRAINDICATIONS REBINYN is contraindicated in patients who have known hypersensitivity to REBINYN or its components (including hamster proteins) [ see Warnings and Precautions ( 5.1 ) and Description ( 11 ) ] Do not use in patients who have known hypersensitivity to REBINYN or its components, including hamster proteins ( 4 ).

ADVERSE REACTIONS Common adverse reactions (incidence ≥ 1%) in PTPs reported in clinical trials for REBINYN were itching and injection site reactions. Common adverse reactions (incidence ≥ 1%) in PUPs reported in clinical trials for REBINYN were rash, FIX inhibitors, hypersensitivity, itching, injection site reaction, and anaphylactic reaction. The most frequently reported adverse reactions (≥ 1%) in previously treated patients (PTPs) and previously untreated patients (PUPs) were itching and injection site reactions ( 6 ). Additional frequently reported adverse reactions (≥ 1%) in PUPs included rash, Factor IX inhibition, hypersensitivity, and anaphylactic reaction ( 6 ). In animals administered repeat doses of REBINYN, accumulation of polyethylene-glycol (PEG) was observed in the choroid plexus, pituitary, circumventricular organs, and cranial motor neurons ( 8.4 and 13.2 ). The potential clinical implications of these animal findings are unknown ( 6.3 ). To report SUSPECTED ADVERSE REACTIONS, contact Novo Nordisk Inc. at 1-877-668-6777 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 clinical trials of another drug and may not reflect the rates observed in clinical practice. Previously Treated Patients (PTPs) In five multicenter, prospective, non-controlled, open-label clinical trials, 115 PTPs [0 to 6 years old: 12 subjects (10%); 7 to 12 years old: 13 subjects (11%); 13 to 17 years old: 18 subjects (16%); ≥18 years old: 72 subjects (63%)] received at least one dose of REBINYN as part of routine prophylaxis, on-demand treatment of bleeding episodes, perioperative management of major and minor surgery, or pharmacokinetic evaluation [ see Clinical Studies (14) ]. A PTP was defined as a subject with a history of at least 150 exposure days to other Factor IX products (adolescent/adult subjects) or 50 exposure days to other Factor IX products (pediatric subjects), and no history of inhibitors. A total of 15,167 injections were administered over a median of 733 days (range: 29- 2951 days), equivalent to 15,137 exposure days and 292 patient-years. Adverse reactions in PTPs are listed in Table 3. Table 3: Summary of Adverse Reactions in Previously Treated Patients System Organ Class Adverse Reaction Number of subjects (%) N=115 General disorders and administration site conditions Injection site reactions 4 (4) Immune system disorders Hypersensitivity 1 (1) Skin and subcutaneous tissue disorders Itching 3 (3) Previously Untreated Patients (PUPs) In one multicenter, prospective, non-controlled, open-label clinical trial conducted in PUPs, 50 subjects (≤6 years of age) received at least one dose of REBINYN [see Clinical Studies (14) ]. A PUP was defined as a subject previously untreated or exposed to FIX-containing products less than or equal to 3 exposure days (5 previous exposures to blood components was acceptable). A total of 6,737 injections were administered over a median of 996 days (range: 61- 2,233 days), equivalent to 6,709 exposure days and 142 patient-years. Adverse reactions in PUPs are listed in Table 4. Table 4: Summary of Adverse Reactions in Previously Untreated Patients System Organ Class Adverse Reaction Number of subjects (%) N=50 Blood and lymphatic system disorders Factor IX inhibition 4 (8) General disorders and administration site conditions Injection site reaction 1 (2) Immune system disorders Anaphylactic reaction Hypersensitivty 1 (2) 3 (6) Skin and subcutaneous tissue disorders Rash Itching 9 (18) 2 (4) 6.2 Immunogenicity Subjects were monitored for inhibitory antibodies to factor IX prior to dosing, on a monthly basis for the first three months, every two months up to one year, every three months for an additional year, and then every 6 months until end of trial. No inhibitors were reported in the clinical trials in previously treated patients. In an ongoing trial in previously untreated patients, one anaphylactic reaction has occurred with development of a factor IX inhibitor following treatment with REBINYN. Inhibitor development and anaphylactic reactions are more likely to occur during the early phases of factor IX replacement therapy [ see Warnings and Precautions ( 5.1 , 5.2 ) ]. 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. 6.3 Neurologic Considerations Animals administered repeat doses of REBINYN showed accumulation of PEG in the choroid plexus, pituitary, circumventricular organs, and cranial motor neurons [ see Use in Specific Populations ( 8.4 ) and Animal Toxicology and/or Pharmacology ( 13.2 ) ]. The potential clinical implications of these animal findings are unknown. In the pediatric studies, 47 PUPs and 25 PTPs receiving routine prophylaxis with REBINYN at a weekly dose of 40 IU/kg were followed for central nervous system (CNS)-related ADRs for 6 and 8 years, respectively. The median duration of follow up of ADRs in the PUP and PTP studies were 2 and 7 years, respectively. Furthermore, neurological examinations were prospectively conducted in 44 PUPs and 17 PTPs with a median follow up of 2 years, and neurocognitive assessments were prospectively performed in 38 PUPs and 16 PTPs with a median follow up of 1 year. Although no clear clinical implications of the animal findings are known and no clear clinical neurologic or neurocognitive safety signal has emerged, the physician should consider whether the patient is vulnerable to cognitive impairment, such as infants and children who have developing brains, and patients who are cognitively impaired. Factors such as duration of use, cumulative dose, age of the patient and co-morbidities that may increase risk of adverse neurologic and/or neurocognitive events should be considered when prescribing REBINYN. Report adverse neurocognitive and neurologic reactions. 6.4 Postmarketing Experience The following adverse reactions have been identified during post-approval use of REBINYN. Because these 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. Blood and lymphatic system disorders: Factor IX inhibitor development.

Mechanism of Action Hemophilia B is a sex-linked hereditary disorder of blood coagulation caused by a deficiency in factor IX and results in bleeding into joints, muscles or internal organs, either spontaneously or as a result of accidental or surgical trauma. Treatment with IXINITY replaces factor IX, thereby enabling a temporary correction of the factor deficiency and correction of the bleeding tendencies.