Source: European Medicines Agency (EU) Revision Year: 2020 Publisher: Alexion Europe SAS, 103-105 rue Anatole France, 92300, Levallois-Perret, France
Strensiq is indicated for long-term enzyme replacement therapy in patients with paediatric-onset hypophosphatasia to treat the bone manifestations of the disease (see section 5.1).
Treatment should be initiated by a physician experienced in the management of patients with metabolic or bone disorders.
Recommended dosage regimen of asfotase alfa is 2 mg/kg of body weight administered subcutaneously three times per week, or a dosage regimen of 1 mg/kg of body weight administered subcutaneously six times per week. Maximum recommended dose of asfotase alfa is 6 mg/kg/week (see Section 5.1).
Refer to the dosing chart below for more details.
| Body Weight (kg) | If injecting 3x per week | If injecting 6 x per week | ||||
|---|---|---|---|---|---|---|
| Dose to be injected | Volume to be injected | Vial type used for injection | Dose to be injected | Volume to be injected | Vial type used for injection | |
| 3 | 6 mg | 0.15 ml | 0.3 ml | |||
| 4 | 8 mg | 0.20 ml | 0.3 ml | |||
| 5 | 10 mg | 0.25 ml | 0.3 ml | |||
| 6 | 12 mg | 0.30 ml | 0.3 ml | 6 mg | 0.15 ml | 0.3 ml |
| 7 | 14 mg | 0.35 ml | 0.45 ml | 7 mg | 0.18 ml | 0.3 ml |
| 8 | 16 mg | 0.40 ml | 0.45 ml | 8 mg | 0.20 ml | 0.3 ml |
| 9 | 18 mg | 0.45 ml | 0.45 ml | 9 mg | 0.23 ml | 0.3 ml |
| 10 | 20 mg | 0.50 ml | 0.7 ml | 10 mg | 0.25 ml | 0.3 ml |
| 11 | 22 mg | 0.55 ml | 0.7 ml | 11 mg | 0.28 ml | 0.3 ml |
| 12 | 24 mg | 0.60 ml | 0.7 ml | 12 mg | 0.30 ml | 0.3 ml |
| 13 | 26 mg | 0.65 ml | 0.7 ml | 13 mg | 0.33 ml | 0.45 ml |
| 14 | 28 mg | 0.70 ml | 0.7 ml | 14 mg | 0.35 ml | 0.45 ml |
| 15 | 30 mg | 0.75 ml | 1 ml | 15 mg | 0.38 ml | 0.45 ml |
| 16 | 32 mg | 0.80 ml | 1 ml | 16 mg | 0.40 ml | 0.45 ml |
| 17 | 34 mg | 0.85 ml | 1 ml | 17 mg | 0.43 ml | 0.45 ml |
| 18 | 36 mg | 0.90 ml | 1 ml | 18 mg | 0.45 ml | 0.45 ml |
| 19 | 38 mg | 0.95 ml | 1 ml | 19 mg | 0.48 ml | 0.7 ml |
| 20 | 40 mg | 1.00 ml | 1 ml | 20 mg | 0.50 ml | 0.7 ml |
| 25 | 50 mg | 0.50 ml | 0.8 ml | 25 mg | 0.63 ml | 0.7 ml |
| 30 | 60 mg | 0.60 ml | 0.8 ml | 30 mg | 0.75 ml | 1 ml |
| 35 | 70 mg | 0.70 ml | 0.8 ml | 35 mg | 0.88 ml | 1 ml |
| 40 | 80 mg | 0.80 ml | 0.8 ml | 40 mg | 1.00 ml | 1 ml |
| 50 | 50 mg | 0.50 ml | 0.8 ml | |||
| 60 | 60 mg | 0.60 ml | 0.8 ml | |||
| 70 | 70 mg | 0.70 ml | 0.8 ml | |||
| 80 | 80 mg | 0.80 ml | 0.8 ml | |||
| 90 | 90 mg | 0.90 ml | 0.8 ml (x2) | |||
| 100 | 100 mg | 1.00 ml | 0.8 ml (x2) | |||
If a dose of asfotase alfa is missed, a double dose should not be injected to make up for the missed dose.
The pharmacokinetics, pharmacodynamics, and safety of asfotase alfa have been studied in patients with hypophosphatasia > 18 years old. Dose adjustment is not needed in adult patients with paediatric- onset hypophosphatasia (HPP) (see Sections 5.1 and 5.2).
The safety and efficacy of asfotase alfa in elderly patients have not been established and no specific dose regimen can be recommended for these patients.
The safety and efficacy of asfotase alfa in patients with renal impairment have not been evaluated and no specific dose regimen can be recommended for these patients.
The safety and efficacy of asfotase alfa in patients with hepatic impairment have not been evaluated and no specific dose regimen can be recommended for these patients.
Strensiq is for subcutaneous use only. It is not intended for intravenous or intramuscular injection. The maximum volume of medicinal product per injection should not exceed 1 ml. If more than 1 ml is required, multiple injections may be administered at the same time. Strensiq should be administered using sterile disposable syringes and injection needles. The syringes should be of small enough volume that the prescribed dose can be withdrawn from the vial with reasonable accuracy.
Injections sites should be rotated and carefully monitored for signs of potential reactions (see section 4.4).
Patients can self-inject only if they have properly been trained on administration procedures. For handling of the medicinal product before administration, see section 6.6.
There is limited experience with overdose of asfotase alfa. The maximum dose of asfotase alfa used in clinical studies is 28 mg/kg/week. No dose-related toxicity or change in the safety profile has been observed in clinical studies. Therefore, no overdose level has been determined. For management of adverse reactions, see sections 4.4 and 4.8.
Shelf life: 2 years.
Chemical and physical in-use stability has been demonstrated for up to 3 hours at a temperature between 23°C to 27°C.
Store in a refrigerator (2°C–8°C).
Do not freeze.
Store in the original package in order to protect from light.
For storage conditions after first opening of the medicinal product, see section 6.3.
Type I glass vial with a stopper (butyl rubber) and a seal (aluminium) with a flip-off cap
(polypropylene).
Strensiq 40 mg/ml solution for injection: Filled volumes of the vials are: 0.3 ml, 0.45 ml, 0.7 ml and 1.0 ml
Strensiq 100 mg/ml solution for injection: Filled volumes of the vials are: 0.8 ml
Pack sizes of 1 or 12 vials.
Not all pack sizes may be marketed.
Each vial is intended for single use only and should only be punctured once. Any unused solution in the vial should be discarded.
Strensiq should be administered using sterile disposable syringes and injection needles. The syringes should be of small enough volume that the prescribed dose can be withdrawn from the vial with reasonable accuracy. An aseptic technique should be used.
Any unused medicinal product or waste material should be disposed of in accordance with local requirements.
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