Asfotase Alfa Dosage

Medically reviewed by Drugs.com. Last updated on Jul 5, 2023.

Applies to the following strengths: 18 mg/0.45 mL; 28 mg/0.7 mL; 40 mg/mL; 80 mg/0.8 mL

Usual Adult Dose for Hypophosphatasia

2 mg/kg subcutaneously 3 times per week OR 1 mg/kg subcutaneously 6 times per week
Maximum dose: 9 mg/kg per week

Comments:

For patients with perinatal/infantile-onset hypophosphatasia (HPP), an increase to 3 mg/kg three times per week may be necessary for insufficient efficacy (e.g., no improvement in respiratory status, growth, or radiographic findings).
Injection site reactions may limit the tolerability of the 6 times per week dosing regimens.

Use: For the treatment of patients with perinatal/infantile and juvenile onset HPP.

2 mg/kg subcutaneously 3 times per week OR 1 mg/kg subcutaneously 6 times per week
Maximum dose: 9 mg/kg per week

Comments:

For patients with perinatal/infantile-onset hypophosphatasia (HPP), an increase to 3 mg/kg three times per week may be necessary for insufficient efficacy (e.g., no improvement in respiratory status, growth, or radiographic findings).
For patients weighing less than 40 kg: Do not use the 80 mg/0.8 mL vial because the systemic exposure is lower than that achieved with the lower strength vials and may not be adequate for these patients.
Injection site reactions may limit the tolerability of the 6 times per week dosing regimens.

Use: For the treatment of patients with perinatal/infantile and juvenile onset HPP.

Data not available

Data not available

CONTRAINDICATIONS:

Clinical studies included patients from 1 day to 58 years of age.

Consult WARNINGS section for additional precautions.

Data not available

Administration advice:

Administer subcutaneously into the abdominal area, thigh, or deltoid
Always use a new syringe and needle; do not share syringes or needles
Rotate injection sites to reduce risk of lipodystrophy; do not administer into reddened, inflamed, or swollen areas

Storage requirements:

Store in the refrigerator [2C to 8C (36F to 46F)] in the original carton until time of use; protect from light
Once removed from refrigerator, use within 1 hour
Do not freeze or shake vial; single-use only

Reconstitution/preparation techniques:

Administer dose within 1 hour of removing vial from the refrigerator.
Do not use 80 mg/0.8 mL vial in patients weighing less than 40 kg.
For injection volumes greater than 1 mL, split dose equally between 2 injections and use 2 separate injection sites.
Vial should be clear, slightly opalescent or opalescent, colorless to slightly yellow aqueous solution; few small translucent or white particles may be present; discard vials not consistent with this description.
Manufacturer product labeling should be consulted for weight-based dosing tables and more specific administration guidance.

General:

Hypophosphatasia (HPP) Registry: A voluntary registry has been established to better understand the HPP population and to monitor and evaluate the long-term treatment effects of this drug; information can be found at www.hppregistry.com.
In clinical trials, anti-drug antibodies were detected; no correlation between anti-drug antibody titer and percent inhibition was observed. The formation of anti-drug antibody resulted in a reduction in systemic exposure.

Monitoring:

Signs and symptoms of hypersensitivity reactions
Signs and symptoms of lipodystrophy
Ophthalmologic exams and renal ultrasounds at baseline and periodically during treatment to monitor for ectopic calcifications

Patient advice:

Patients or caregivers should be instructed on preparation, storage, and administration of this drug; proper injection technique and site rotation are necessary to avoid injection site reactions.
Patients or caregivers should be instructed on proper disposal of needles and syringes; with each dose, a new syringe and needle should be used and needles and syringes should never be shared.
If signs or symptoms of an allergic reaction occur, patients should seek immediate medical advice.
Tell your health care provider if you notice skin thickening or pits at injection sites.