Strensiq logo Dosing and administration STRENSIQ® (asfotase alfa) is indicated for long-term enzyme replacement therapy in patients with paediatric-onset hypophosphatasia (HPP) to treat the bone manifestations of the disease.1 To date, this is the first and only approved treatment in this indication,2–4 supported by up to 7 years of clinical data.2–7

This medicinal product is subject to additional monitoring. This will allow quick identification of new safety information. Please report any adverse events via your national reporting system. Adverse events can also be reported to Alexion Pharmaceuticals by contacting:
https://contactazmedical.astrazeneca.com.
Please refer to the Summary of Product Characteristics for further information.
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The maximum recommended dose of STRENSIQ® is 6 mg/kg of body weight per week as either:1
Icon of a syringe next to a medicine bottle Icon of a syringe next to a medicine bottle
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.1


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 The syringes should be of small enough volume that the prescribed dose can be withdrawn from the vial with reasonable accuracy.1

Injection sites should be rotated and carefully monitored for signs of potential reactions.1

Injections can be self-administered at home or by a carer. Patients can only self-inject if they have been properly trained on administration procedures. For handling of the medicinal product before administration, please refer to section 6.6 of the SmPC.1
Please refer to the dosing chart available in the STRENSIQ® Summary of Product Characteristics. The calculator below may help with calculating the necessary STRENSIQ® dosing values.1

Drag the button across the slider bar to select your patient's body weight (kg). The body weight variable will automatically snap to the nearest recognised figure in line with the STRENSIQ® weight-based dosing.
For optimal dosing, patient weight should be checked regularly. STRENSIQ® is for subcutaneous use only. It is not intended for intravenous or intramuscular injection.1
For more information on the dosing and administration schedule of STRENSIQ®, please see the Summary of Product Characteristics.1
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HPP, hypophosphatasia.
This medicinal product has been authorised under ‘exceptional circumstances’. This means that due to the rarity of the disease it has not been possible to obtain complete information on this medicinal product.

▼This medicinal product is subject to additional monitoring. This will allow quick identification of new safety information. Please report any adverse events via your national reporting system. Adverse events can also be reported to Alexion Pharmaceuticals by the following link: https://contactazmedical.astrazeneca.com/
STRENSIQ® Summary of Product Characteristics. Alexion Europe SAS. Available at https://www.ema.europa.eu/en/documents/product-information/strensiq-epar-product-information_en.pdf. Last accessed: June 2025. Whyte MP, et al. Asfotase alfa for infants and young children with hypophosphatasia: 7 year outcomes of a single-arm, open-label, phase 2 extension trial. Lancet Diabetes Endocrinol. 2019;7(2):93–105. European Medicines Agency. EPAR for Strensiq. 2024. Available at: https://www.ema.europa.eu/en/medicines/human/EPAR/strensiq#product-info. Last accessed: June 2025. Jaswanthi N, et al. Effect of Asfotase Alfa in the Treatment of Hypophosphatasia- A Systematic Review. J Pharm Bioallied Sci. 2023;15(Suppl 1):S101-S104. Hofmann CE, et al. Efficacy and Safety of Asfotase Alfa in Infants and Young Children With Hypophosphatasia: A Phase 2 Open-Label Study. J Clin Endocrinol Metab. 2019;104(7):2735–2747. Whyte MP, et al. Asfotase alfa therapy for children with hypophosphatasia. JCI Insight. 2016;1(9):e85971. Kishnani PS, et al. Five-year efficacy and safety of asfotase alfa therapy for adults and adolescents with hypophosphatasia. Bone. 2019;121:149–162.