阿福他酶α(asfotase alfa)用法用量:推荐剂量,剂量减少、不良反应剂量调整

The injection dose of asfotase alfa needs to be individually adjusted according to the patient's weight. The specific dosage regimen should be determined by the clinician after a comprehensive assessment of the patient's disease severity, treatment response and tolerance.

Afotalase α usage and dosage

1. Dosage of perinatal/infant-onset hypophosphatasia

The recommended dosage regimen of afotalase α for the treatment of perinatal/infant-onset HPP is 6 mg/kg per week, administered subcutaneously, as follows:

(1) 2 mg/kg three times a week, or 1 mg/kg six times a week. Injection site reactions may limit tolerability of the six-weekly regimen.

(2) Due to lack of efficacy (e.g., no improvement in respiratory status, growth, or imaging findings), the dose of aftase alfa may be increased to 9 mg/kg per week or 3 mg/kg subcutaneously three times per week.

2. Dosage of adolescent-onset hypophosphatasia

The recommended dosage regimen of aftase alfa for the treatment of adolescent-onset HPP is 6 mg/kg per week, administered subcutaneously, as follows:

3 times a week, 2 mg/kg each time, or six times a week, 1 mg/kg each time. Injection site reactions may limit tolerability of the six-weekly regimen.

Afotalase α dose adjustment

1. Recommended dose adjustment

Determine the total weekly volume required for the prescribed dose based on the patient's weight and recommended dose. Please follow the steps below to determine patient dosage:

(1) Total weekly dose (mg) = patient weight (kg) × prescribed dose (mg/kg/week)

(2) Total weekly injection volume (mL) = total dose (mg/week) divided by STRENSIQ concentration (40mg/mL or 100mg/mL). Please note that the product concentration is: 40mg/mL (vial concentration 18mg/0.45mL, 28mg/0.7mL, 40mg/mL) or 100mg/mL (vial concentration 80mg/0.8mL).

(3) Round the total injection volume to the nearest hundredth of mL.

(4) Total number of vials per week = total injection volume divided by vial volume (mL).

2. Determine the number of injection days per week (three to six days per week).

3. Determine the dose for each injection day

When determining the dose, the patient's weight should be rounded to the nearest kilogram. For patients dosing 2 mg/kg three times weekly, 1 mg/kg six times weekly, and for patients escalating to 3 mg/kg three times weekly, use the table below as a guide, recommended only for patients with perinatal/infantile-onset hypophosphatasia.

4. Body weight-based dosage of 2 mg/kg three times a week

(5) Body weight is 3 kg, injection dose is 6 mg, injection volume is 0.15 ml, sample bottle preparation is 18 mg/0.45 ml.

(6) The body weight is 4 kg, the injection dose is 8 mg, the injection volume is 0.2 ml, and the sample bottle preparation is 18 mg/0.45 ml.

(7) The body weight is 5 kg, the injection dose is 10 mg, the injection volume is 0.25 ml, and the sample bottle preparation is 18 mg/0.45 ml.

(8) The body weight is 6 kg, the injection dose is 12 mg, the injection volume is 0.3 ml, and the sample bottle preparation is 18 mg/0.45 ml.

(9) The body weight is 7 kg, the injection dose is 14 mg, the injection volume is 0.35 ml, and the sample bottle preparation is 18 mg/0.45 ml.

(10) The body weight is 8 kg, the injection dose is 16 mg, the injection volume is 0.4 ml, and the sample bottle preparation is 18 mg/0.45 ml.

(11) The body weight is 9 kg, the injection dose is 18 mg, the injection volume is 0.45 ml, and the sample bottle preparation is 18 mg/0.45 ml.

(12) The body weight is 10 kg, the injection dose is 20 mg, the injection volume is 0.5 ml, and the sample bottle preparation is 28 mg/0.7 ml.

(13) The body weight is 15 kg, the injection dose is 30 mg, the injection volume is 0.75 ml, and the sample bottle preparation is 40 mg/1 ml.

(14) The body weight is 20 kg, the injection dose is 40 mg, the injection volume is 1 ml, and the sample bottle preparation is 40 mg/1 ml.

(15) The body weight is 25 kg, the injection dose is 50 mg, the injection volume is 1.25 ml, and the sample bottle is prepared with two 28 mg/0.7 mL sample bottles.

(16) The body weight is 30 kg, the injection dose is 60 mg, the injection volume is 1.5 ml, and the sample bottle is prepared with two 40 mg/1mL sample bottles.

(17) The body weight is 35 kg, the injection dose is 70 mg, the injection volume is 1.75 ml, and the sample bottle is prepared with two 40 mg/1mL sample bottles.

(18) The body weight is 40 kg, the injection dose is 80 mg, the injection volume is 0.8 ml, and the sample bottle preparation is 80 mg/0.8 ml.

(19) The body weight is 50 kg, the injection dose is 100 mg, the injection volume is 1 ml, and the sample bottles are prepared with two 80 mg/0.8 mL sample bottles.

(20) The body weight is 60 kg, the injection dose is 120 mg, the injection volume is 1.2 ml, and the sample bottle is prepared with two 80 mg/0.8 mL sample bottles.

(21) The body weight is 70 kg, the injection dose is 140 mg, the injection volume is 1.4 ml, and the sample bottle is prepared with two 80 mg/0.8 mL sample bottles.

(22) The body weight is 80 kg, the injection dose is 160 mg, the injection volume is 1.6 ml, and the sample bottle is prepared with two 80 mg/0.8 mL sample bottles.

5. Body weight-based dose of 1 mg/kg 6 times a week

(1) Body weight 3 kg, injection dose 3 mg, injection volume 0.08 ml, sample bottle preparation 18 mg/0.45 ml.

(2) The body weight is 4 kg, the injection dose is 4 mg, the injection volume is 0.1 ml, and the sample bottle preparation is 18 mg/0.45 ml.

(3) The body weight is 5 kg, the injection dose is 5 mg, the injection volume is 0.13 ml, and the sample bottle preparation is 18 mg/0.45 ml.

(4) The body weight is 6 kg, the injection dose is 6 mg, the injection volume is 0.15 ml, and the sample bottle preparation is 18 mg/0.45 ml.

(5) The body weight is 7 kg, the injection dose is 7 mg, the injection volume is 0.18 ml, and the sample bottle preparation is 18 mg/0.45 ml.

(6) The body weight is 8 kg, the injection dose is 8 mg, the injection volume is 0.2 ml, and the sample bottle preparation is 18 mg/0.45 ml.

(7) The body weight is 9 kg, the injection dose is 9 mg, the injection volume is 0.23 ml, and the sample bottle preparation is 18 mg/0.45 ml.

(8) The body weight is 10 kg, the injection dose is 10 mg, the injection volume is 0.25 ml, and the sample bottle preparation is 18 mg/0.45 ml.

(9) The body weight is 15 kg, the injection dose is 15 mg, the injection volume is 0.38 ml, and the sample bottle preparation is 18 mg/0.45 ml.

(10) The body weight is 20 kg, the injection dose is 20 mg, the injection volume is 0.5 ml, and the sample bottle preparation is 28 mg/0.7 ml.

(11) The body weight is 25 kg, the injection dose is 25 mg, the injection volume is 0.63 ml, and the sample bottle preparation is 28 mg/0.7 ml.

(12) The body weight is 30 kg, the injection dose is 30 mg, the injection volume is 0.75 ml, and the sample bottle preparation is 40 mg/1 ml.

(13) The body weight is 35 kg, the injection dose is 35 mg, the injection volume is 0.88 ml, and the sample bottle preparation is 40 mg/1 ml.

(14) The body weight is 40 kg, the injection dose is 40 mg, the injection volume is 1 ml, and the sample bottle preparation is 40 mg/1 ml.

(15) The body weight is 50 kg, the injection dose is 50 mg, the injection volume is 0.5 ml, and the sample bottle preparation is 80 mg/0.8 ml.

(16) The body weight is 60 kg, the injection dose is 60 mg, the injection volume is 0.6 ml, and the sample bottle preparation is 80 mg/0.8 ml.

(17) The body weight is 70 kg, the injection dose is 70 mg, the injection volume is 0.7 ml, and the sample bottle preparation is 80 mg/0.8 ml.

(18) The body weight is 80 kg, the injection dose is 80 mg, the injection volume is 0.8 ml, and the sample bottle preparation is 80 mg/0.8 ml.

(19) The body weight is 90 kg, the injection dose is 90 mg, the injection volume is 0.9 ml, and the sample bottles are prepared with two 80 mg/0.8 mL sample bottles.

(20) The body weight is 100 kg, the injection dose is 100 mg, the injection volume is 1 ml, and the sample bottles are prepared with two 80 mg/0.8 mL sample bottles.

4. Body weight-based dosage of 3 mg/kg three times a week

Only applicable to perinatal/infant-onset hypophosphatasia:

(1) Body weight 3 kg, injection dose 9 mg, injection volume 0.23 ml, sample bottle configuration 18 mg/0.45 ml.

(2) The body weight is 4 kg, the injection dose is 12 mg, the injection volume is 0.3 ml, and the sample bottle configuration is 18 mg/0.45 ml.

(3) The body weight is 5 kg, the injection dose is 15 mg, the injection volume is 0.38 ml, and the sample bottle configuration is 18 mg/0.45 ml.

(4) The body weight is 6 kg, the injection dose is 18 mg, the injection volume is 0.45 ml, and the sample bottle configuration is 18 mg/0.45 ml.

(5) The body weight is 7 kg, the injection dose is 21 mg, the injection volume is 0.53 ml, and the sample bottle configuration is 28 mg/0.7 ml.

(6) The body weight is 8 kg, the injection dose is 24 mg, the injection volume is 0.6 ml, and the sample bottle configuration is 28 mg/0.7 ml.

(7) The body weight is 9 kg, the injection dose is 27 mg, the injection volume is 0.68 ml, and the sample bottle configuration is 28 mg/0.7 ml.

(8) The body weight is 10 kg, the injection dose is 30 mg, the injection volume is 0.75 ml, and the sample bottle configuration is 40 mg/1 ml.

(9) The body weight is 15 kg, the injection dose is 45 mg, the injection volume is 1.13 ml, and the sample bottle is equipped with two 28mg/0.7mL sample bottles.

(10) The body weight is 20 kg, the injection dose is 60 mg, the injection volume is 1.5 ml, and the sample bottle is equipped with two 40 mg/1mL sample bottles.

(11) The body weight is 25 kg, the injection dose is 75 mg, the injection volume is 1.88 ml, and the sample bottle is equipped with two 40 mg/1mL sample bottles.

Precautions for the use of aftase α

1. Remove the unopened vial of aftase α from the refrigerator 15 to 30 minutes before injection and allow the liquid to reach room temperature.

2. Do not heat aphthase α in any other way (e.g., do not heat in microwave or hot water).

3. Check the solution in the vial for particles and discoloration. Aftase alfa is supplied as a clear, slightly opalescent or opalescent, colorless to slightly yellow aqueous solution; some small translucent or white particles may be present. Discard any vial that does not appear consistent with this appearance.

4. Assemble injection supplies. Use a sterile disposable 1 mL syringe and a 1/2-inch needle to administer aftase alfa, recommended between 25 and 29 gauge. It is recommended to use two different specifications of needles, a large-diameter needle (such as 25-gauge) for withdrawal, and a small-diameter needle (such as 29-gauge) for injection. For doses greater than 1 mL, the injection volume should be divided equally between two 1 mL syringes. Always use a new syringe and needle for each injection.

5. Remove the cap of the vial, prepare the vial aseptically and insert the syringe into the vial, take out the prescribed dose and administer it. Don't shake.

6. Remove all air bubbles from the syringe and verify correct dosage.

7. The aphthase α vial is for one-time use only. Discard any unused product.

Afotalase alfa medication management

Afotalase alfa is for subcutaneous injection only:

1. When giving two injections, please use two separate injection sites.

2. Administer aftase alfa within 3 hours after removing the vial from refrigeration.

3. Inject in turn from the following areas to reduce the risk of lipodystrophy: abdomen, thigh, deltoid or buttocks.

4. Do not inject in areas that are red, inflamed or swollen.

5. Inject aftase alfa subcutaneously into the determined site and dispose of the syringe and needle properly.