IMPORTANT SAFETY INFORMATION INCLUDING BOXED WARNING

What is the most important information I should know about STRENSIQ?
Severe allergic (hypersensitivity) reactions have occurred with STRENSIQ treatment and can be severe and life-threatening. Severe allergic reactions have happened in some people within minutes after receiving STRENSIQ and more than 1 year after starting
treatment with STRENSIQ.

What are the possible side effects of STRENSIQ?
STRENSIQ may cause serious side effects, including:
Severe allergic (hypersensitivity) reactions. Allergic reactions are
common with STRENSIQ treatment and can be severe and life threatening. Severe allergic reactions have happened in some people within minutes after receiving STRENSIQ and more than 1 year after starting treatment with 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 severe allergic reaction:

• difficulty breathing
• choking sensation
• swelling of your eyes, lips, or tongue
• itching or numbness of the
  tongue, lips, cheeks, or gums
• dizziness
• nausea or vomiting

Call your doctor if you experience any of the following signs and symptoms of an allergic reaction: fever, headache, sweating, feeling irritable, chills, skin redness, skin rash or hives.

Skin thickening or pits at the injection site (lipodystrophy) has happened several months after using STRENSIQ.

Calcium buildup in the eyes and kidneys. People with HPP are at increased risk for developing calcium build-up due to disease and may be a side effect of STRENSIQ, although it may also occur in untreated patients. Your healthcare provider should check your eyes and kidneys before and during
treatment with STRENSIQ.

Immune-related effects. You may develop antibodies during
treatment that may decrease how well STRENSIQ works. Tell your healthcare provider right away if you get worsening symptoms of HPP including difficulty breathing or walking, feeling tired, bone pain, stiff joints, or loss of appetite.

The most common side effects of STRENSIQ include local skin injection-site reactions (skin redness, bruising, color change, pain, itching, swelling, and bumps).

These are not all the possible side effects of STRENSIQ. For more information, ask your healthcare provider or pharmacist.

Before using STRENSIQ, tell your healthcare provider about all your medical conditions, including if
you:

• have had an allergic reaction to STRENSIQ
• are pregnant or plan to become pregnant. It is not known if STRENSIQ will harm your unborn baby.
• are breastfeeding or plan to breastfeed. It is not known if STRENSIQ passes into your breast milk. Talk to your healthcare provider about the best way to feed your baby if you use STRENSIQ.

Tell your healthcare provider about all the medicines you take,
including prescription and over-the-counter medicines, vitamins, and herbal supplements.

There is a registry for people who use STRENSIQ. The purpose of this registry is to collect information about HPP and about what happens when you use STRENSIQ for a long time. For more information about this registry, talk with your healthcare provider or go to www.hppregistry.com.

Call your healthcare provider for medical advice about side effects. To report SUSPECTED SIDE EFFECTS, contact Alexion
Pharmaceuticals, Inc. at
1-844-259-6783 or FDA at 1- 800-FDA-1088 or www.fda.gov/
medwatch

Please see the full Prescribing Information, and Patient Information for STRENSIQ
(asfotase alfa), including Boxed
WARNING regarding severe allergic (hypersensitivity) reaction

INDICATION

What is STRENSIQ?
STRENSIQ® (asfotase alfa) is a prescription medicine used to treat people with perinatal, infantile, and juvenile onset hypophosphatasia (HPP).