Stay Connected

Take the next step with Strensiq® (asfotase alfa).

Strensiq: the first and only prescription medicine used to treat people with perinatal/infantile- and juvenile-onset hypophosphatasia (HPP)
Learn more about how Strensiq
treats Hypophosphatasia

Strensiq® treats the underlying cause of hypophosphatasia
low alkaline phosphatase (ALP) activity.

Strensiq, Alkaline Phosphatase (ALP)

Personalized support. Every step of the way.

OneSource™ offers personalized support
throughout your treatment journey.

Learn More
  • Education and tools to help with your disease and treatment
  • Connections with other people living with hypophosphatasia
  • Information on co-pay support and financial assistance programs
  • Treatment support from dedicated Alexion nurse case managers
  • Alexion Access Foundation for those without insurance
  • Specialized medication refrigerator to help store Strensiq and track injections
  • In-home injection training by trained professionals
A safe and convenient mail-back program to help dispose of needles



Strensiq is a prescription medicine used to treat people with perinatal/infantile- and juvenile-onset hypophosphatasia (HPP).

What are the possible side effects of STRENSIQ?
STRENSIQ may cause serious side effects, including
  • Serious allergic (hypersensitivity) reactions happened in some people who use STRENSIQ. Stop using STRENSIQ and go to the nearest hospital emergency room right away if you or your loved one have any of the signs and symptoms of a serious allergic reaction, including
    • Difficulty breathing
    • Swelling of your eyes, lips, or tongue
    • Hives
    • Feeling faint
    • Nausea or vomiting
    • Dizziness
    • Itching of your lips, tongue, or throat
    • Choking sensation
  • Skin thickening or pits at the injection site (lipodystrophy) has happened several months after using STRENSIQ.
  • Calcium buildup in the eyes and kidneys can occur if you or your loved one have HPP. Your healthcare provider should check the eyes and kidneys while you or your loved one use STRENSIQ.
  • Decreased efficacy. Contact your healthcare provider if you or your loved one notice STRENSIQ is no longer working or experience worsening symptoms of HPP (e.g., increased respiratory support, increased difficulty walking, new fractures).
The most common side effects of STRENSIQ include local skin injection-site reactions (including red skin patches, bruising, color change, pain, itching, thinning, swelling, pits, and bumps) and calcium buildup in your eyes and kidneys.

Strensiq may affect other lab test results, therefore it is important that you present your Medical Alert Card to your healthcare team so they are aware that you are being treated with an alkaline phosphatase (ALP) replacement therapy which may cause incorrect results on certain laboratory tests.

 Tell your doctor if you are pregnant or plan to become pregnant, or are breastfeeding or plan to breastfeed.

These are not all the possible side effects of STRENSIQ. For more information, ask your healthcare provider or pharmacist. Call your healthcare provider for medical advice about side effects. You may report side effects to the US Food and Drug Administration at 1-800-FDA-1088.

Please see STRENSIQ full Prescribing Information, including Patient Information and Instructions for Use.

Get the most out of your medical visits.

View our list of suggested questions to ask your doctor, nurse, or pharmacist.

Questions to ask