Crysvita® (burosumab-twza)

The first and only FDA-approved therapy for the treatment of XLH and TIO

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Crysvita® (burosumab-twza) is a fibroblast growth factor 23 (FGF23)-blocking antibody indicated for the treatment of:

  • X-linked hypophosphatemia (XLH) in adult and pediatric patients 6 months of age and older.
  • FGF23-related hypophosphatemia in tumor-induced osteomalacia (TIO) associated with phosphaturic mesenchymal tumors that cannot be curatively resected or localized in adult and pediatric patients 2 years of age and older.



  • With oral phosphate and/or active vitamin D analogs (e.g., calcitriol, paricalcitol, doxercalciferol, calcifediol).
  • When serum phosphorus is within or above the normal range for age.
  • In patients with severe renal impairment or end stage renal disease.



  • Discontinue Crysvita if serious hypersensitivity reactions occur and initiate appropriate medical treatment.

Hyperphosphatemia and Risk of Nephrocalcinosis

  • For patients already taking Crysvita, dose interruption and/or dose reduction may be required based on a patient’s serum phosphorus levels.
  • Patients with TIO who undergo treatment of the underlying tumor should have dosing interrupted and adjusted to prevent hyperphosphatemia. 

Injection Site Reactions

  • Discontinue Crysvita if severe injection site reactions occur and administer appropriate medical treatment.


Pediatric XLH Patients

  • Adverse reactions reported in 10% or more of Crysvita-treated pediatric XLH patients across all studies are: pyrexia, injection site reaction, cough, vomiting, pain in extremity, headache, tooth abscess, dental caries, diarrhea, vitamin D decreased, toothache, constipation, myalgia, rash, dizziness, and nausea.
  • Post-marketing experience reported in pediatric XLH patients receiving Crysvita – blood phosphorus increased.

Adult XLH Patients

  • Adverse reactions reported in more than 5% of Crysvita-treated adult XLH patients and in at least 2 patients more than placebo in one study are: back pain, headache, tooth infection, restless legs syndrome, vitamin D decreased, dizziness, constipation, muscle spasms, and blood phosphorus increased.
  • Spinal stenosis is prevalent in adults with XLH, and spinal cord compression has been reported. It is unknown if Crysvita therapy exacerbates spinal stenosis or spinal cord compression.

Adult TIO Patients

  • Adverse reactions reported in more than 10% of Crysvita-treated adult TIO patients in two studies are: tooth abscess, muscle spasms, dizziness, constipation, injection site reaction, rash, and headache.


  • There are no available data on Crysvita use in pregnant women to inform a drug-associated risk of adverse developmental outcomes. Serum phosphorus levels should be monitored throughout pregnancy. Report pregnancies to the Kyowa Kirin, Inc. Adverse Event reporting line at 1-888-756-8657.
  • There is no information regarding the presence of Crysvita in human milk or the effects of Crysvita on milk production or the breastfed infant.


  • Advise patients not to use any oral phosphate and/or active vitamin D analog products.
  • Instruct patients to contact their physician if hypersensitivity reactions, injection site reactions, and restless leg syndrome induction or worsening of symptoms occur.

Report side effects to the FDA at You may also report side effects to Kyowa Kirin, Inc. at 1-888-756-8657.

Please see full Prescribing Information for a complete discussion of the risks associated with Crysvita.