Dosing and uses of Idelvion (Factor IX, recombinant/albumin fusion protein)
Adult dosage forms and strengths
lyophilized powder for reconstitution
- 250 IU
- 500 IU
- 1000 IU
- 2000 IU
Hemophilia B
Indicated for children and adults with hemophilia B (congenital Factor IX deficiency) for
- On-demand control and prevention of bleeding episodes
- Perioperative management of bleeding
- Routine prophylaxis to prevent or reduce the frequency of bleeding episodes
Dose calculation
- Dosage and treatment duration depends on the severity of Factor IX deficiency, the location and extent of bleeding, and the patient’s clinical condition, age, and recovery of Factor IX
- Calculating the required dose is based on the empirical finding that one IU per kg body weight is expected to increase the circulating level of Factor IX by 1.3 IU/dL in patients aged ≥12 yr, and by 1 IU/dL in patients aged <12 yr
- Required units (IU) = Body weight (kg) x desired Factor IX rise (% of normal or IU/dL) x (reciprocal of recovery [IU/dL per IU/kg]), OR
- Increase in Factor IX IU/dL (or % of normal) = Dose (IU) x recovery (IU/dL per IU/kg)/body weight (kg)
- Adjust the dose based on the individual patient’s clinical condition and response
Hemophilia B, Bleeding Episodes
Indicated for on-demand control and prevention of bleeding episodes
Minor or moderate
- Uncomplicated hemarthrosis, muscle bleeding (except iliopsoas), or oral bleeding
- Maintain circulating FIX at 30-60 % or IU/dL; may repeat q48-72hr; duration of at least 1day, until bleeding stops and healing is achieved; single dose should be sufficient for majority of these bleeds
Major
- Life- or limb-threatening hemorrhage; deep muscle bleeding, including iliopsoas, intracranial, and retropharyngeal
- Maintain circulating Factor IX at 60-100 % or IU/dL; may repeat q48-72hr; duration of 7-14 days, until bleeding stops and healing is achieved; consider weekly maintenance dose
Hemophilia B, Perioperative Management
Indicated for perioperative management of bleeding
Minor
- Includes uncomplicated tooth extraction
- Maintain circulating Factor IX at 50-80 % or IU/dL; duration of at least 1day or until healing is achieved; single dose should be sufficient for majority of minor surgeries
Major
- Includes intracranial, pharyngeal, retropharyngeal, or retroperitoneal
- Maintain circulating FactorIX at 60-100 % or IU/dL; repeat q48-72hr for first week or until healing achieved; duration of 7-14 days, until bleeding stops and healing is achieved; maintenance dose 1-2 times per week
Hemophilia B, Routine Prophylaxis
Indicated for routine prophylaxis to prevent or reduce the frequency of bleeding episodes
25-40 IU/kg IV q7days
Patients who are well-controlled on the 7-day regimen may be switched to a 14-day interval regimen of 50-75 IU/kg
Adjust dose based on individual response
Dosing Considerations
Limitation of use: Not indicated for immune tolerance induction in patients with hemophilia B
Pediatric dosage forms and strengths
lyophilized powder for reconstitution
- 250 IU
- 500 IU
- 1000 IU
- 2000 IU
Hemophilia B
Indicated for children and adults with hemophilia B (congenital Factor IX deficiency) for
- On-demand control and prevention of bleeding episodes
- Perioperative management of bleeding
- Routine prophylaxis to prevent or reduce the frequency of bleeding episodes
Dose calculation
- Dosage and treatment duration depends on the severity of Factor IX deficiency, the location and extent of bleeding, and the patient’s clinical condition, age, and recovery of Factor IX
- Calculating the required dose is based on the empirical finding that one IU per kg body weight is expected to increase the circulating level of Factor IX by 1.3 IU/dL in patients aged ≥12 yr, and by 1 IU/dL in patients aged <12 yr
- Required units (IU) = Body weight (kg) x desired Factor IX rise (% of normal or IU/dL) x (reciprocal of recovery [IU/dL per IU/kg]), OR
- Increase in Factor IX IU/dL (or % of normal) = Dose (IU) x recovery (IU/dL per IU/kg)/body weight (kg)
- Adjust the dose based on the individual patient’s clinical condition and response
Hemophilia B, Bleeding Episodes
Indicated for on-demand control and prevention of bleeding episodes
Minor or moderate
- Uncomplicated hemarthrosis, muscle bleeding (except iliopsoas), or oral bleeding
- Maintain circulating Factor IX at 30-60 % or IU/dL; may repeat q48-72hr; duration of at least 1day, until bleeding stops and healing is achieved; single dose should be sufficient for majority of these bleeds
Major
- Life or limb threatening hemorrhage; deep muscle bleeding, including iliopsoas, intracranial, and retropharyngeal
- Maintain circulating Factor IX at 60-100 % or IU/dL; may repeat q48-72hr; duration of 7-14 days, until bleeding stops and healing is achieved; consider weekly maintenance dose
Hemophilia B, Perioperative Management
Indicated for perioperative management of bleeding
Minor
- Includes uncomplicated tooth extraction
- Maintain circulating Factor IX at 50-80 % or IU/dL; duration of at least 1day or until healing is achieved; single dose should be sufficient for majority of minor surgeries
Major
- Includes intracranial, pharyngeal, retropharyngeal, or retroperitoneal
- Maintain circulating Factor IX at 60-100 % or IU/dL; repeat q48-72hr for first week or until healing achieved; duration of 7-14 days, until bleeding stops and healing is achieved; maintenance dose 1-2 times per week
Hemophilia B, Routine Prophylaxis
Indicated for routine prophylaxis to prevent or reduce the frequency of bleeding episodes
<12 years: 40-55 IU/kg IV q7days
≥12 years
- 25-40 IU/kg IV q7days
- Patients who are well-controlled on the 7-day regimen may be switched to a 14-day interval regimen of 50-75 IU/kg
- Adjust dose based on individual response
Dosing Considerations
Limitation of use: Not indicated for immune tolerance induction in patients with hemophilia B
Idelvion (Factor IX, recombinant/albumin fusion protein) adverse (side) effects
1-10%
Headache (1.8%)
<1%
Dizziness
Hypersensitivity
Rash
Eczema
Warnings
Contraindications
Life-threatening hypersensitivity reactions to the drug or its components, including hamster proteins
Cautions
Hypersensitivity reactions, including anaphylaxis, are possible; if hypersensitivity symptoms occur, immediately discontinue administration and initiate appropriate treatment (see Contraindications)
Formation of neutralizing antibodies to Factor IX may occur
Thromboembolism (eg, pulmonary embolism, venous thrombosis, arterial thrombosis) may occur when using Factor IX-containing products
Nephrotic syndrome reported following attempted immune tolerance induction in hemophilia B patients who develop
Patients with Factor IX inhibitors and a history of allergic reactions
Monitor Factor IX plasma levels and development of inhibitors
Pregnancy and lactation
Pregnancy
No data exist regarding use in pregnant women to inform on drug-associated risk
Animal reproduction studies have not been conducted
Should be given to a pregnant woman only if clearly needed
Lactation
Unknown if distributed in human breast milk
Consider the developmental and health benefits of breastfeeding along with the mother’s clinical need for the drug, and any potential adverse effects on the breastfed infant from the drug or from the underlying maternal condition
Pregnancy categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA: Information not available.
Pharmacology of Idelvion (Factor IX, recombinant/albumin fusion protein)
Mechanism of action
Recombinant protein that temporarily replaces missing coagulation Factor IX needed for effective hemostasis
Comprised of genetically fused recombinant coagulation Factor IX and recombinant albumin; fusion with recombinant albumin extends the half-life of Factor IX
Absorption
Peak plasma concentration: 41.1-82 IU/dL
AUC: 4658-9345 h·IU/dL
Distribution
Vd: 0.86-1.2 dL/kg
Elimination
Half-life: 104-188 hr
Mean residence time: 143-153 hr
Clearance: 0.57-0.84 mL/hr/kg
Administration
IV Preparation
Each vial contains the recombinant Factor IX potency in international units (IU) that is stated on the carton and vial labeL
Follow directions within kit by using provided diluent (sterile water for injection) and Mix2Vial provided
IV Administration
For IV use after reconstitution only
Do not mix or administer in the same tubing or container with other medicinal products
Visually inspect the final solution for particulate matter and discoloration; do not use if particulate matter or discoloration observed
Attach the syringe containing the reconstituted solution to a sterile infusion set and administer by IV injection
Adapt the infusion rate to the comfort level of each patient, not exceeding 10 mL/min
Administer at room temperature and within 4 hr of reconstitution
Discard any unused product
Storage
Unreconstituted viaL
- Store in original package to protect from light
- May store in refrigeratory or at room temperature (2-25°C [36-77°F])
- Do not freeze
