Skip to main content

Dosing for patients

Dosing schedule and administration for CRYSVITA1

Adult patients

(18 years of age and older)

Administered by an HCP every 4 weeks. Starting dose is 0.5 mg/kg every 4 weeks. Dose may be increased up to 2 mg/kg not to exceed 180 mg, administered every 2 weeks.

Pediatric patients

CRYSVITA dosing for pediatric patients

(2 years to <18 years of age)*

Administered by an HCP every 2 weeks. Starting dose is 0.4 mg/kg of body weight rounded to the nearest 10 mg every 2 weeks. Dose may be increased up to 2 mg/kg not to exceed 180 mg, administered every 2 weeks.

CRYSVITA administration1

Injection vial
strengths

Ready-to-use subcutaneous injection that comes in: 10 mg/mL, 20 mg/mL, or 30 mg/mL

Injection site
locations

Injection sites should be rotated with each injection administered at a different anatomic location (upper arms, upper thighs, buttocks, or any quadrant of abdomen) than the previous injection. Do not inject into moles, scars, or areas where the skin is tender, bruised, red, hard, or not intact.

*Safety and effectiveness of CRYSVITA in pediatric patients 2 years of age and older with TIO are supported by evidence from the studies in adult patients with TIO with additional modeling and simulation of pharmacokinetic (PK) data from adult and pediatric patients with XLH and adult patients with TIO to inform dosing. Safety and effectiveness for CRYSVITA in pediatric patients with TIO below the age of 2 years have not been established.

Before initiating CRYSVITA1

  • Discontinue oral phosphate and/or active vitamin D analogs (eg, calcitriol, paricalcitol, doxercalciferol, calcifediol) 1 week prior to initiation of treatment
  • Fasting serum phosphorus concentration should be below the reference range for age prior to initiation of treatment
  • CRYSVITA is administered by subcutaneous injection and should be administered by a healthcare provider
  • The maximum volume of CRYSVITA per injection is 1.5 mL. If multiple injections are required, administer at different injection sites

After initiating CRYSVITA1

  • Monitor fasting serum phosphorus level every 4 weeks, measured 2 weeks post-dose for the first 3 months of treatment and thereafter, as appropriate
  • If serum phosphorus is within the normal range, continue with the same dose

Dose adjustments in adults1

  • Reassess fasting serum phosphorus level 2 weeks after dose adjustment
  • Do not adjust the dose of CRYSVITA more frequently than every 4 weeks
  • Dose increase: If serum phosphorus is below the normal range, the CRYSVITA dose may be increased stepwise up to a maximum dose of 2 mg/kg, not to exceed 180 mg, administered every 2 weeks, according to the dose schedule in the full Prescribing Information

Dose decrease:

If serum phosphorus is above the normal range, withhold the next dose and reassess the fasting serum phosphorus level in 4 weeks. The patient must have serum phosphorus below the reference range to reinitiate CRYSVITA. Once serum phosphorus is below the reference range, treatment may be restarted at approximately half the initial starting dose, up to a maximum dose of 180 mg, administered every 2 weeks.

After a dose decrease, reassess the fasting serum phosphorus level 2 weeks after the dose adjustment. If the level remains below the reference range after the reinitiation dose, the dose can be adjusted, as outlined in the full Prescribing Information.

Dose interruption:

If a patient undergoes treatment of the underlying tumor, such as surgical excision or radiation therapy, treatment with CRYSVITA should be interrupted and serum phosphorus reassessed after treatment has been completed. If the serum phosphorus level remains below the lower limit of normal, the CRYSVITA dose should be restarted at the patient’s initiation dose. The dose may be adjusted following the dose schedule in the full Prescribing Information to maintain serum phosphorus levels within the reference range.

Dose adjustments in children1

  • Reassess fasting serum phosphorus level 4 weeks after dose adjustment
  • Do not adjust the dose of CRYSVITA more frequently than every 4 weeks
  • Dose increase: If serum phosphorus is below the reference range for the patient's age, the dose of CRYSVITA may be increased stepwise up to the maximum dose of 2 mg/kg, not to exceed 180 mg, administered every 2 weeks, according to the dose schedule shown in the full Prescribing Information

Dose decrease:

If serum phosphorus is above the reference range for age, withhold the next dose and reassess the fasting serum phosphorus level in 4 weeks. The patient must have serum phosphorus below the reference range for age to reinitiate CRYSVITA. Once serum phosphorus is below the reference range for age, treatment may be restarted at approximately half the initial starting dose, up to a maximum dose of 180 mg, administered every 2 weeks.

After a dose decrease, reassess the fasting serum phosphorus level 4 weeks after the dose adjustment. If the level remains below the reference range for age after the reinitiation dose, the dose can be adjusted, as outlined in the full Prescribing Information.

Dose interruption:

If a patient undergoes treatment of the underlying tumor, such as surgical excision or radiation therapy, CRYSVITA treatment should be interrupted and serum phosphorus reassessed after treatment has been completed. If serum phosphorus level remains below the lower limit of normal, CRYSVITA dose should be restarted at the patient’s initiation dose. The dose may be adjusted following the dose schedule in the full Prescribing Information to maintain serum phosphorus levels within the reference range for age.

CRYSVITA dosing is based on a patient's weight. Continue to monitor their weight and make any dose adjustments as indicated in the full Prescribing Information.1

Ready to start your patients on CRYSVITA?

Take the first step by filling out the enrollment form.

Enrollment Form

Stay connected

Set up time with a representative to talk more about CRYSVITA.

REQUEST A REP

Indication

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

Indication

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

Important Safety Information

CONTRAINDICATIONS

CRYSVITA is contraindicated:

  • In concomitant use with oral phosphate and/or active vitamin D analogs (e.g., calcitriol, paricalcitol, doxercalciferol, calcifediol) due to the risk of hyperphosphatemia.
  • When serum phosphorus is within or above the normal range for age.
  • In patients with severe renal impairment or end stage renal disease because these conditions are associated with abnormal mineral metabolism.

WARNINGS AND PRECAUTIONS

Hypersensitivity

  • Hypersensitivity reactions (e.g., rash, urticaria) have been reported in patients with CRYSVITA. Discontinue CRYSVITA if serious hypersensitivity reactions occur and initiate appropriate medical treatment.

Hyperphosphatemia and Risk of Nephrocalcinosis

  • Increases in serum phosphorus to above the upper limit of normal may be associated with an increased 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 who undergo treatment of the underlying tumor should have dosing interrupted and adjusted to prevent hyperphosphatemia.

Injection Site Reactions

  • Administration of CRYSVITA may result in local injection site reactions. Discontinue CRYSVITA if severe injection site reactions occur and administer appropriate medical treatment.

ADVERSE REACTIONS

Adult Patients

  • Adverse reactions reported in more than 10% of CRYSVITA-treated adult TIO patients in two studies are: tooth abscess (19%), muscle spasms (19%), dizziness (15%), constipation (15%), injection site reaction (15%), rash (15%), and headache (11%).

USE IN SPECIFIC POPULATIONS

  • 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 1-844-768-3544.
  • There is no information regarding the presence of CRYSVITA in human milk or the effects of CRYSVITA on milk production or the breastfed infant. Therefore, the developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for CRYSVITA and any potential adverse effects on the breastfed infant from CRYSVITA or from the underlying maternal condition.

PATIENT COUNSELING INFORMATION

  • 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 legs syndrome induction or worsening of symptoms occur.

You may report side effects to the FDA at (800) FDA-1088 or www.fda.gov/medwatch. You may also report side effects to Kyowa Kirin, Inc. at 1-844-768-3544.

For important risk and use information, please see the full Prescribing Information for CRYSVITA.

Indication

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

Important Safety Information

CONTRAINDICATIONS

CRYSVITA is contraindicated:

  • In concomitant use with oral phosphate and/or active vitamin D analogs (e.g., calcitriol, paricalcitol, doxercalciferol, calcifediol) due to the risk of hyperphosphatemia.
  • When serum phosphorus is within or above the normal range for age.
  • In patients with severe renal impairment or end stage renal disease because these conditions are associated with abnormal mineral metabolism.

WARNINGS AND PRECAUTIONS

Hypersensitivity

  • Hypersensitivity reactions (e.g., rash, urticaria) have been reported in patients with CRYSVITA. Discontinue CRYSVITA if serious hypersensitivity reactions occur and initiate appropriate medical treatment.

Hyperphosphatemia and Risk of Nephrocalcinosis

  • Increases in serum phosphorus to above the upper limit of normal may be associated with an increased 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 who undergo treatment of the underlying tumor should have dosing interrupted and adjusted to prevent hyperphosphatemia.

Injection Site Reactions

  • Administration of CRYSVITA may result in local injection site reactions. Discontinue CRYSVITA if severe injection site reactions occur and administer appropriate medical treatment.

ADVERSE REACTIONS

Adult Patients

  • Adverse reactions reported in more than 10% of CRYSVITA-treated adult TIO patients in two studies are: tooth abscess (19%), muscle spasms (19%), dizziness (15%), constipation (15%), injection site reaction (15%), rash (15%), and headache (11%).

USE IN SPECIFIC POPULATIONS

  • 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 1-844-768-3544.
  • There is no information regarding the presence of CRYSVITA in human milk or the effects of CRYSVITA on milk production or the breastfed infant. Therefore, the developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for CRYSVITA and any potential adverse effects on the breastfed infant from CRYSVITA or from the underlying maternal condition.

PATIENT COUNSELING INFORMATION

  • 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 legs syndrome induction or worsening of symptoms occur.

You may report side effects to the FDA at (800) FDA-1088 or www.fda.gov/medwatch. You may also report side effects to Kyowa Kirin, Inc. at 1-844-768-3544.

For important risk and use information, please see the full Prescribing Information for CRYSVITA.

Reference:

1. CRYSVITA (burosumab-twza). US Prescribing Information. Kyowa Kirin, Inc.; March 2023.