Important safety information related to taking CRYSVITA® (burosumab-twza)

Learn about the potential side effects related to taking CRYSVITA

Learn about the potential side effects related to taking CRYSVITA

You should not take CRYSVITA if:

  • You take an oral phosphate supplement and/or a specific form of vitamin D supplement (such as calcitriol, paricalcitol, doxercalciferol, calcifediol)
  • Your phosphorus levels from a blood sample are within or above the normal range for age
  • You have kidney problems

What is the most important information I should know about CRYSVITA?

  • Some patients developed allergic reactions (e.g., rash and hives) while taking CRYSVITA. Your doctor will monitor you for symptoms of an allergic reaction while you are taking CRYSVITA
  • High levels of phosphorus in the blood have been reported in some patients taking CRYSVITA. This may be related to a risk of high calcium levels in the kidneys. Your doctor will collect samples to monitor your levels
  • Administration of CRYSVITA may result in reactions at the injection site, such as hives, reddening of the skin, rash, swelling, bruising, pain, severe itching of the skin, and collection of blood outside of a blood vessel (i.e., hematoma)
Potential side effects of CRYSVITA in children

What are the possible side effects of CRYSVITA in children?

The following side effects were observed in 10% or more of children who were treated with CRYSVITA across all studies

The most common side effects reported in children with XLH who were treated with CRYSVITA were:

  • Fever
  • Injection site reaction
  • Cough
  • Vomiting
  • Pain in arms and legs
  • Headache
  • Tooth infection
  • Dental cavities
  • Diarrhea
  • Decreased vitamin D levels
  • Toothache
  • Constipation
  • Muscle pain
  • Rash
  • Dizziness
  • Nausea

Before your child starts taking CRYSVITA, tell your child’s doctor about all of their medications (including supplements) and medical conditions, including if they:

  • are taking oral phosphate and/or active vitamin D (such as calcitriol, paricalcitol, doxercalciferol, calcifediol)
Potential side effects of CRYSVITA in adults

What are the possible side effects of CRYSVITA in adults?

The following side effects were observed in more than 5% of adults who were treated with CRYSVITA every 4 weeks and in at least 2 patients more than with placebo in the first 24 weeks of Study 4

The most common side effects reported in adults with XLH who were treated with CRYSVITA were:

  • Back pain
  • Headache
  • Tooth infection
  • Restless leg syndrome
  • Decreased vitamin D levels
  • Dizziness
  • Constipation
  • Muscle spasms
  • Phosphorus levels increased in the blood

Narrowing of the spaces within the spine is common in adults with XLH, and pressure on the spinal cord has been reported in adults taking CRYSVITA. It is not known if taking CRYSVITA worsens the narrowing of the spaces within the spine or the pressure on the spinal cord.

Before taking CRYSVITA, tell your doctor about all of your medications (including supplements) and medical conditions, including if you:

  • are taking oral phosphate and/or active vitamin D (such as calcitriol, paricalcitol, doxercalciferol, calcifediol)
  • are pregnant, think you may be pregnant, or plan to become pregnant. There is not enough experience to know if CRYSVITA may harm your unborn baby. Report pregnancies to the Kyowa Kirin, Inc. Adverse Event reporting line at 1-888-756-8657
  • are breastfeeding or plan to breastfeed. There is not enough experience to know if CRYSVITA passes into your breast milk. Talk with your doctor about the best way to feed your baby while you receive CRYSVITA