Drug Class Description
Antihaemorrhagic Blood Coagulation Factor IX
Generic Name
Factor IX [nonacog alfa]
Drug Description
BeneFIX 250 IU, BeneFIX 500 IU, BeneFIX 1000 IU, BeneFIX 2000 IU powder and solvent for solution for injection.
Presentation
White/almost white powder and clear and colourless solvent for solution for injection.
Indications
Treatment and prophylaxis of bleeding in patients with haemophilia B (congenital factor IX deficiency).
Adult Dosage
Treatment should be initiated under the supervision of a physician experienced in the treatment of haemophilia.PosologyThe dosage and duration of the substitution therapy depends on the severity of the factor IX deficiency, the location and extent of bleeding, and the patient's clinical condition. Dosing of BeneFIX may differ from that of plasma-derived factor IX products.To ensure that the desired factor IX activity level has been achieved, precise monitoring using the factor IX activity assay is advised and doses should be calculated taking the factor IX activity, pharmacokinetic parameters such as half-life and recovery, as well as the clinical situation into consideration in order to adjust the dose as appropriate.The amount to be administered and the frequency of administration should always be oriented to the clinical effectiveness in the individual case. Factor IX products rarely require to be administered more than once daily.The number of units of factor IX administered is expressed in International Units (IU), which are related to the current WHO standard for factor IX products. Factor IX activity in plasma is expressed either as a percentage (relative to normal human plasma) or in International Units (relative to an international standard for factor IX in plasma).One International Unit (IU) of factor IX activity is equivalent to that quantity of factor IX in one ml of normal human plasma. Estimation of the required dose of BeneFIX can be based on the finding that one unit of factor IX activity per kg body weight is expected to increase the circulating level of factor IX, an average of 0.8 IU/dl (range from 0.4 to 1.4 IU/dl) in adult patients ( 15 years). Pharmacokinetics have to be assessed regularly in each patient and posology has to be adjusted accordingly.The required dosage is determined using the following formula:Number of factor IX IU required=body weight (in kg)Xdesired factor IX increase (%) or (IU/dl)Xreciprocal of observed recoveryFor a recovery 0.8 IU/dl (average increase of factor IX), then:Number of factor IX IU required=body weight (in kg)Xdesired factor IX increase (%) or (IU/dl)X1.3 IU/kg In the case of the following haemorrhagic events, the factor IX activity should not fall below the given plasma activity levels (in % of normal or in IU/dl) in the corresponding period. The following table can be used to guide dosing in bleeding episodes and surgery:Degree of haemorrhage/Type of surgical procedureFactor IX level required (%) or (IU/dl)Frequency of doses (hours)/Duration of Therapy (days)Haemorrhage Early haemarthrosis, muscle bleeding or oral bleeding20-40Repeat every 24 hours. At least 1 day, until the bleeding episode as indicated by pain is resolved or healing is achieved.More extensive haemarthrosis, muscle bleeding or haematoma30-60Repeat infusion every 24 hours for 3-4 days or more until pain and acute disability are resolved.Life-threatening haemorrhages60-100Repeat infusion every 8 to 24 hours until threat is resolved.SurgeryMinor: Including tooth extraction Major30-6080-100pre- and postoperativeEvery 24 hours, at least 1 day, until healing is achieved. Repeat infusion every 8-24 hours until adequate wound healing, then therapy for at least another 7 days to maintain a factor IX activity of 30% to 60% (IU/dl)During the course of treatment, appropriate determination of factor IX levels is advised to guide the dose to be administered and the frequency of repeated infusions. In the case of major surgical interventions in particular, precise monitoring of the substitution therapy by means of coagulation analysis (plasma factor IX activity) is indispensable. Individual patients may vary in their response to factor IX, achieving different levels of in vivo recovery and demonstrating different half-lives.For long term prophylaxis against bleeding in patients with severe haemophilia B, BeneFIX may be administered. In a clinical study for routine secondary prophylaxis the average dose for previously treated patients (PTP) was 40 IU/kg (range 13 to 78 IU/kg) at intervals of 3 to 4 days. In younger patients, shorter dosage intervals or higher doses may be necessary.Paediatric patientsThere are insufficient data to recommend the use of BeneFIX in children less than 6 years of age. In clinical studies, 57% of the paediatric patients increased their doses due to lower than expected recovery or to obtain sufficient therapeutic response or both, some to an average dose of >50 IU/kg. Therefore, close monitoring of factor IX plasma activity should be performed, as well as calculation of pharmacokinetic parameters such as recovery and half-life, as clinically indicated, in order to adjust doses as appropriate. If doses >100 IU/kg have been repeatedly needed during routine prophylaxis or treatment, a switch to another FIX product should be considered.Patients should be monitored for the development of factor IX inhibitors. If the expected factor IX activity plasma levels are not attained, or if bleeding is not controlled with an appropriate dose, biological testing should be performed to determine if a factor IX inhibitor is present.In patients with high levels of inhibitor factor IX therapy may not be effective and other therapeutic options must be considered. Management of such patients should be directed by physicians with experience in the care of patients with haemophilia.Method of administrationBeneFIX is administered by intravenous infusion after reconstitution of the lyophilised powder for solution for injection with sterile 0.234% sodium chloride solution.BeneFIX should be administered at a slow infusion rate. In most of the cases, an infusion rate of up to 4 ml per minute has been used. The rate of administration should be determined by the patient's comfort level.
Child Dosage
There are insufficient data to recommend the use of BeneFIX in children less than 6 years of age. In clinical studies, 57% of the paediatric patients increased their doses due to lower than expected recovery or to obtain sufficient therapeutic response or both, some to an average dose of>50 IU/kg. Therefore, close monitoring of factor IX plasma activity should be performed, as well as calculation of pharmacokinetic parameters such as recovery and half-life, as clinically indicated, in order to adjust doses as appropriate. If doses>100 IU/kg have been repeatedly needed during routine prophylaxis or treatment, a switch to another FIX product should be considered.
Contra Indications
Hypersensitivity to the active substance or to any of the excipients.Known allergic reaction to hamster proteins.
Special Precautions
Activity-neutralizing antibodies (inhibitors) are an uncommon event in previously treated patients (PTPs) receiving factor IX-containing products. Since during clinical studies one PTP treated with BeneFIX developed a clinically relevant low responding inhibitor and experience on antigenicity with recombinant factor IX is still limited, patients treated with BeneFIX should be carefully monitored for the development of factor IX inhibitors that should be titrated in Bethesda Units using appropriate biological testing.Sufficient data have not been obtained from ongoing clinical studies on the treatment of previously untreated patients (PUPs), with BeneFIX. Additional safety and efficacy studies in paediatric patients are ongoing in previously treated, minimally treated, and previously untreated paediatric patients. Clinical studies of BeneFIX did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects. As with any patient receiving BeneFIX, dose selection for an elderly patient should be individualised.As with any intravenous protein product, allergic-type hypersensitivity reactions are possible. The product contains traces of hamster proteins. Potentially life-threatening anaphylactic/anaphylactoid reactions have occurred with factor IX products, including BeneFIX. Patients should be informed of early signs of hypersensitivity reactions including difficult breathing, shortness of breath, swelling, hives, itching, tightness of the chest, bronchospasm, laryngospasm, wheezing, hypotension, blurred vision, and anaphylaxis.If allergic or anaphylactic-type reactions occur, the administration of BeneFIX has to be discontinued immediately and an appropriate treatment has to be initiated. In some cases, these reactions have progressed to severe anaphylaxis. In the case of shock, the current medical standards for treatment of shock should be observed. In case of severe allergic reactions, alternative haemostatic measures should be considered.There have been reports in the literature showing a correlation between the occurrence of a factor IX inhibitor and allergic reactions. Therefore, patients experiencing allergic reactions should be eva luated for the presence of an inhibitor. It should be noted that patients with factor IX inhibitors may be at an increased risk of anaphylaxis with subsequent challenge with factor IX. Preliminary information suggests a relationship may exist between the presence of major deletion mutations in a patient's factor IX gene and an increased risk of inhibitor formation and of acute hypersensitivity reactions. Patients known to have major deletion mutations of the factor IX gene should be observed closely for signs and symptoms of acute hypersensitivity reactions, particularly during the early phases of initial exposure to product.Because of the risk of allergic reactions with factor IX concentrates, the initial administrations of factor IX should, according to the treating physician's judgement, be performed under medical observation where proper medical care for allergic reactions could be provided.Posology has to be adjusted according to the pharmacokinetics of each patient.Although BeneFIX contains only factor IX, the risk of thrombosis and disseminated intravascular coagulation (DIC) should be recognised. Since the use of factor IX complex concentrates has historically been associated with the development of thromboembolic complications, the use of factor IX-containing products may be potentially hazardous in patients with signs of fibrinolysis and in patients with disseminated intravascular coagulation (DIC). Because of the potential risk of thrombotic complications, clinical surveillance for early signs of thrombotic and consumptive coagulopathy should be initiated with appropriate biological testing when administering this product to patients with liver disease, to patients post-operatively, to neonates, or to patients at risk of thrombotic phenomena or DIC. In each of these situations, the benefit of treatment with BeneFIX should be weighed against the risk of these complications.The safety and efficacy of BeneFIX administration by continuous infusion have not been established. There have been post-marketing reports of thrombotic events, including lifethreatening superior vena cava (SVC) syndrome in critically ill neonates, while receiving continuousinfusion BeneFIX through a central venous catheter.There have been reports of agglutination of red blood cells in the tube/syringe with the administration of BeneFIX. So far, no clinical sequelae have been reported in association with this observation. To minimize the possibility of agglutination, it is important to limit the amount of blood entering the tubing. Blood should not enter the syringe. If agglutination of red blood cells in the tubing/syringe is observed, discard all this material (tubing, syringe and BeneFIX solution) and resume administration with a new package.Nephrotic syndrome has been reported following attempted immune tolerance induction in haemophilia B patients with Factor IX inhibitors and a history of allergic reaction. The safety and efficacy of using BeneFIX for immune tolerance induction has not been established.In the interest of patients, it is recommended that, whenever possible, every time that BeneFIX is administered to them, the name and batch number of the product is registered.
Interactions
No interaction studies have been performed.
Adverse Reactions
To date, no adverse reactions reported in association with BeneFIX occurred with a frequency of 1/100 to <1/10 (common). The frequency of adverse reactions reported in association with BeneFIX would be categorized as uncommon (1/1000 to 1/100) or rare (1/10,000 to 1/1000). Of these the most significant include: anaphylaxis, cellulitis, phlebitis, and neutralising antibodies.Adverse reactions based on experience from clinical trials and postmarketing experience are presented below by system organ class and frequency of occurrence. Within each frequency grouping, undesirable effects are presented in order of decreasing seriousness. These frequencies have been estimated on a per-infusion basis and are described using the following categories: uncommon (1/1000 to 1/100); rare (1/10,000 to 1/1000).Nervous system disordersUncommon: Dizziness, headache, altered taste, lightheadednessGastrointestinal disordersUncommon: NauseaRare: VomitingGeneral disorders and administration site conditionsUncommon: Cellulitis, phlebitis, injection site reaction (including burning infusion site and injection site stinging), injection site discomfortRare: PyrexiaImmune system disordersUncommon: Neutralising antibodies (factor IX inhibition)*Rare: Hypersensitivity/allergic reactions; such reactions may include anaphylaxis*, bronchospasm/respiratory distress, hypotension, angioedema, tachycardia, chest tightness, generalised urticarial, hives, rash, burning sensation in jaw and skull, chills (rigors), tingling, flushing, lethargy, restlessness, dry cough/sneezing* See additional information below.Hypersensitivity/allergic reactionsHypersensitivity or allergic reactions have been infrequently observed in patients treated with factor IX containing products, including BeneFIX. In some cases, these reactions have progressed to severe anaphylaxis. Allergic reactions have occurred in close temporal association with development of factor IX inhibitor. The aetiology of the allergic reactions to BeneFIX has not yet been elucidated. These reactions are potentially lifethreatening. If allergic/anaphylactic reactions occur, the administration of BeneFIX should be discontinued at once. In case of severe allergic reactions, alternative haemostatic measures should be considered. The treatment required depends on the nature and severity of side-effect. Due to the production process BeneFIX contains trace amounts of hamster cell proteins. Hypersensitivity responses can occur.Inhibitor developmentPatients with haemophilia B may develop neutralising antibodies (inhibitors) to factor IX. If such inhibitors occur, the condition may manifest itself as an insufficient clinical response. In such cases, it is recommended that a specialised haemophilia centre be contacted. A clinically relevant, low responding inhibitor was detected in 1 out of 65 BeneFIX patients (including 9 patients participating only in the surgery study) who had previously received plasma derived products. This patient was able to continue treatment with BeneFIX with no anamnestic rise in inhibitor or anaphylaxis. There are insufficient data to provide information on inhibitor incidence in PUPs.Nephrotic syndrome has been reported following high doses of plasma derived Factor IX to induce immune tolerance in haemophilia B patients with factor IX inhibitors and a history of allergic reactions.RenalIn a clinical trial, twelve days after a dose of BeneFIX for a bleeding episode, one hepatitis C antibody positive patient developed a renal infarct. The relationship of the infarct to prior administration of BeneFIX is uncertain. The patient continued to be treated with BeneFIX.
Manufacturer
Wyeth Pharmaceuticals
Drug Availability
(POM)
Updated
20 August 2010
