IXINITY- coagulation factor ix (recombinant)
Medexus Pharma, Inc.


IXINITY, Coagulation Factor IX (Recombinant), is a human blood coagulation factor indicated in adults and children ≥ 12 years of age with hemophilia B for:

  • On-demand treatment and control of bleeding episodes
  • Perioperative management
  • Routine prophylaxis to reduce the frequency of bleeding episodes

IXINITY is not indicated for induction of immune tolerance in patients with hemophilia B [see Warnings and Precautions (5.3) ].


For intravenous use after reconstitution only.

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

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.

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.

For an incremental recovery of 0.98 IU/dL per IU/kg, 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):

  1. 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 × (0.98 IU/dL per IU/kg)/(70 kg) = 64 IU/dL (approximately 60% of normal)
  2. 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
  • 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

The dose for previously treated patients (PTPs) is 40 to 70 IU/kg twice weekly. 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
   Pre-op 60-80
   Post-op 40-6030-5020-40 8-24 1-34-67-14

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