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CRYSVITA® (burosumab-twza) injection 10, 20, 30 mg/mL

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Get answers to common questions about CRYSVITA (burosumab-twza) and its use in the treatment of XLH

About CRYSVITA

CRYSVITA is indicated for the treatment of X-linked hypophosphatemia (XLH) in adult and pediatric patients 6 months of age and older.1

For other CRYSVITA use information, please see the full Prescribing Information.

CRYSVITA is a FGF23 blocking antibody that targets the underlying cause of chronic hypophosphatemia in XLH—excess FGF23.1,2 It binds to and inhibits the biological activity of FGF23, restoring renal phosphate reabsorption and increasing serum concentration of active vitamin D.1


For more information on CRYSVITA and how it works, please see mechanism of action.

CRYSVITA is manufactured by Kyowa Kirin, Inc. (U.S. License No. 2077).1

Mechanism of action for CRYSVITA

CRYSVITA is the only targeted therapy to address the underlying causes of chronic hypophosphatemia in XLH.1,3 It is a human monoclonal antibody specifically designed to inhibit the activity of FGF23.1

In XLH, CRYSVITA-mediated inhibition of FGF23 is thought to1,4:

  • Increase renal phosphate reabsorption via increased expression of sodium phosphate co-transporters
  • Upregulate renal expression of 1α-hydroxylase and reduce expression of 24-hydroxylase, which together act to increase serum concentration of active vitamin D, leading to increased intestinal phosphate absorption
For more information on CRYSVITA and how it works, please see mechanism of action.

Efficacy and safety of CRYSVITA

Children

A phase 3 study in children with XLH between 1 and 12 years of age showed that CRYSVITA1:

  • Helped heal rickets and reduce rickets severity
  • Increased growth
  • Increased and sustained serum phosphorus levels
Adults

Two phase 3 studies in adults with XLH showed that CRYSVITA1:

  • Increased and maintained serum phosphorus levels
  • Helped heal fractures and osteomalacia
For more information on the efficacy of CRYSVITA in clinical studies, please see:

Efficacy & safety in children

Efficacy & safety in adults

CRYSVITA is contraindicated1:
  • In concomitant use with oral phosphate and/or active vitamin D analogs (eg, 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
For other important risk and use information for CRYSVITA, please see the full Prescribing Information.

The warnings and precautions for CRYSVITA are1:
  • Hypersensitivity: Hypersensitivity reactions (eg, 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
  • Hypercalcemia: Increases in serum calcium have been reported in patients treated with CRYSVITA. Patients with risk factors such as pre-existing hyperparathyroidism, prolonged immobilization, dehydration, hypervitaminosis D, or renal impairment, are at higher risk of hypercalcemia. Monitor these patients for serum calcium and parathyroid hormone levels before and during CRYSVITA treatment for moderate to severe hypercalcemia. In patients with moderate to severe hypercalcemia, CRYSVITA should not be administered until hypercalcemia is adequately managed
  • 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
For other important risk and use information for CRYSVITA, please see the full Prescribing Information.

Children

The most common adverse reactions (in ≥25% in the CRYSVITA group and greater than active control) in pediatric patients with XLH were pyrexia, injection site reaction, cough, vomiting, pain in extremity, headache, tooth abscess, and dental caries.1


Adults

The most common adverse reactions (in >5% of CRYSVITA-treated patients and in at least 2 patients more than placebo) in adult patients with XLH were back pain, headache, tooth infection, restless legs syndrome, vitamin D decreased, dizziness, constipation, muscle spasms, and blood phosphorus increased.1


For more information on the safety of CRYSVITA in clinical studies, please see:

Efficacy & safety in children

Efficacy & safety in adults

Advise patients not to use any oral phosphate and/or active vitamin D analog products.1

Instruct patients to contact their physician if hypersensitivity reactions, injection site reactions, and restless legs syndrome induction or worsening of symptoms occur.1

For other patient counseling information for CRYSVITA, please see the full Prescribing Information.

Dosage, administration, and storage for CRYSVITA

Children

The recommended starting dose for patients 6 months to <18 years of age who weigh1:

  • <10 kg is 1 mg/kg of body weight, rounded to the nearest 1 mg, administered every 2 weeks
  • ≥10 kg is 0.8 mg/kg of body weight, rounded to the nearest 10 mg, administered every 2 weeks. The minimum starting dose is 10 mg up to a maximum dose of 90 mg
Adults

The recommended starting dose for patients ≥18 years of age is 1 mg/kg of body weight, rounded to the nearest 10 mg, every 4 weeks. Doses may be increased up to 90 mg, administered every 4 weeks.1


For more information on the dosing for CRYSVITA, please see:

Dosage for children

Dosage for adults

Children

Measure fasting serum phosphorus levels every 4 weeks for the first 3 months of treatment and thereafter, as appropriate.


Adults

Assess fasting serum phosphorus on a monthly basis, measured 2 weeks post-dose, for the first 3 months of treatment and thereafter, as appropriate.


For more information on the assessment schedule for CRYSVITA, please see:

Dosage for children

Dosage for adults

Children

Upon assessment, if fasting serum phosphorus levels are above the lower limit of the reference range for age and below 5 mg/dL, continue treatment with the same dose. To maintain serum phosphorus levels within the reference range for age, adjust the dose as indicated in the full Prescribing Information.1


Adults

Upon assessment, if fasting serum phosphorus is within the normal range, continue with the same dose. To maintain serum phosphorus levels within the normal range, adjust the dose as indicated in the full Prescribing Information.1

For more information on dosage adjustments for CRYSVITA, please see:

Dosage for children

Dosage for adults

CRYSVITA should be administered by an HCP and via subcutaneous injection only. Injection sites should be rotated with each injection, administered at a different anatomic location than the previous injection. Injection site locations include1:

  • Upper arms
  • Upper thighs
  • Buttocks
  • Any quadrant of the abdomen
Do not inject into moles, scars, or areas where the skin is tender, bruised, red, hard, or not intact.1

For more information on the administration of CRYSVITA and general considerations, please see:

Dosage for children

Dosage for adults

CRYSVITA is a sterile, preservative-free, clear to slightly opalescent and colorless to pale brown-yellow solution for subcutaneous injection. Do not use if the solution is discolored or cloudy or if the solution contains any particles or foreign particulate matter.1


For more information on the administration of CRYSVITA and general considerations, please see:

Dosage for children

Dosage for adults

If a patient misses a dose, resume CRYSVITA as soon as possible at the prescribed dose. To avoid missed doses, treatments may be administered 3 days either side of the scheduled treatment date.1

CRYSVITA should be administered by a healthcare professional, such as a registered nurse or physician. Administration can occur at the patient’s home, a medical facility, or another appropriate site of care.1

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CRYSVITA vials must be stored in the original carton until the time of use under refrigerated conditions at 36°F to 46°F (2°C to 8°C). Keep the CRYSVITA vial in the original carton to protect it from light until the time of use.1

  • Do not freeze or shake CRYSVITA
  • Do not use CRYSVITA beyond the expiration date stamped on the carton
  • CRYSVITA vials are single-dose only. Discard any unused product
For more information on storing and handling CRYSVITA, please see supply & storage.

Treatment considerations for CRYSVITA

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
1-844-768-3544.1

For more information on the use of CRYSVITA in specific populations, please see the full Prescribing Information.

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.1

For more information on the use of CRYSVITA in specific populations, please see the full Prescribing Information.

CRYSVITA is contraindicated in concomitant use with oral phosphate and/or active vitamin D analogs (eg, calcitriol, paricalcitol, doxercalciferol, calcifediol) due to the risk of hyperphosphatemia.1

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

Access and support for CRYSVITA

The Kyowa Kirin Cares program helps patients understand their financial options based on their insurance coverage (commercial, government, or no insurance) and offers access support for eligible patients. 95% of eligible, commercially insured patients who were enrolled in the Kyowa Kirin Cares Co-Pay Assistance Program had $0 out-of-pocket costs for CRYSVITA.6*

For more information on access and reimbursement assistance for CRYSVITA, please see patient access & support.

*Data on File, May 2024.

Kyowa Kirin Cares provides patients with ongoing support throughout their journeys with CRYSVITA.

A Case Manager can help healthcare professionals and their patients NAVIGATE treatment:

  • Assist with logistical information regarding access, reimbursement, and financial options
  • Explain how to work with specialty pharmacies
  • Support patients throughout their treatment journeys

A Clinical Educator can help EDUCATE patients about disease and treatment:

  • Help answer questions about XLH and CRYSVITA
  • Provide tools and resources to help patients stay on track
  • Connect with patients along their treatment journey
For more information on patient support and access to helpful resources, please see:

Patient access & support

Resources for your practice & patients

CRYSVITA can be procured and dispensed by an authorized Specialty Distributor or from a select group of Specialty Pharmacies. Ordering requirements may differ based on the patient’s coverage. A dedicated Field Reimbursement Manager from Kyowa Kirin Cares will work with the prescriber to coordinate a procurement option based on the patient’s benefits.

For more information about the procurement and dispensing of CRYSVITA, please call Kyowa Kirin Cares at 833-KK-CARES (833-552-2737) Monday through Friday, 8 AM to 8 PM (ET) or talk to a representative.


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FGF23=fibroblast growth factor 23; XLH=X-linked hypophosphatemia.

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Set up time with a representative to talk more about CRYSVITA or sign up for more information on CRYSVITA for the treatment of XLH.

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Indication

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.

read more
Indication

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.

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.

Hypercalcemia

  • Increases in serum calcium have been reported in patients treated with CRYSVITA. Patients with risk factors such as pre-existing hyperparathyroidism, prolonged immobilization, dehydration, hypervitaminosis D, or renal impairment, are at higher risk of hypercalcemia. Monitor these patients for serum calcium and parathyroid hormone levels before and during CRYSVITA treatment for moderate to severe hypercalcemia. In patients with moderate to severe hypercalcemia, CRYSVITA should not be administered until hypercalcemia is adequately managed.

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

Pediatric Patients

  • Adverse reactions reported in 10% or more of CRYSVITA-treated pediatric XLH patients across three studies are: pyrexia (55%, 44%, and 62%), injection site reaction (52%, 67%, and 23%), cough (52%), vomiting (41%, 48%, and 46%), pain in extremity (38%, 46%, and 23%), headache (34% and 73%), tooth abscess (34%, 15%, and 23%), dental caries (31%), diarrhea (24%), vitamin D decreased (24%, 37%, and 15%), toothache (23% and 15%), constipation (17%), myalgia (17%), rash (14% and 27%), dizziness (15%), and nausea (10%).

Adult 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 (15%), headache (13%), tooth infection (13%), restless legs syndrome (12%), vitamin D decreased (12%), dizziness (10%), constipation (9%), muscle spasms (7%), and blood phosphorus increased (6%).
  • 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.

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 at 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 X-linked hypophosphatemia (XLH) in adult and pediatric patients 6 months 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.

Hypercalcemia

  • Increases in serum calcium have been reported in patients treated with CRYSVITA. Patients with risk factors such as pre-existing hyperparathyroidism, prolonged immobilization, dehydration, hypervitaminosis D, or renal impairment, are at higher risk of hypercalcemia. Monitor these patients for serum calcium and parathyroid hormone levels before and during CRYSVITA treatment for moderate to severe hypercalcemia. In patients with moderate to severe hypercalcemia, CRYSVITA should not be administered until hypercalcemia is adequately managed.

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

Pediatric Patients

  • Adverse reactions reported in 10% or more of CRYSVITA-treated pediatric XLH patients across three studies are: pyrexia (55%, 44%, and 62%), injection site reaction (52%, 67%, and 23%), cough (52%), vomiting (41%, 48%, and 46%), pain in extremity (38%, 46%, and 23%), headache (34% and 73%), tooth abscess (34%, 15%, and 23%), dental caries (31%), diarrhea (24%), vitamin D decreased (24%, 37%, and 15%), toothache (23% and 15%), constipation (17%), myalgia (17%), rash (14% and 27%), dizziness (15%), and nausea (10%).

Adult 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 (15%), headache (13%), tooth infection (13%), restless legs syndrome (12%), vitamin D decreased (12%), dizziness (10%), constipation (9%), muscle spasms (7%), and blood phosphorus increased (6%).
  • 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.

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 at 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.

References:

  • 1. CRYSVITA (burosumab-twza). US Prescribing Information. Kyowa Kirin, Inc.; August 2025. 2. Glorieux FH, Bonewald LF, Harvey NC, van der Meulen M. Potential influences on optimizing long-term musculoskeletal health in children and adolescents with X-linked hypophosphatemia (XLH). Orphanet J Rare Dis. 2022;17(1):30. doi:10.1186/s13023-021-02156-x 3. Carpenter TO, Imel EA, Ruppe MD, et al. Randomized trial of the anti-FGF23 antibody KRN23 in X-linked hypophosphatemia. J Clin Invest. 2014;124(4):1587-1597. doi:10.1172/JCI72829 4. Aono Y, Yamazaki Y, Yasutake J, et al. Therapeutic effects of anti-FGF23 antibodies in hypophosphatemic rickets/osteomalacia. J Bone Miner Res. 2009;24(11):1879-1888. doi:10.1359/jbmr.090509 5. Erben RG, Andrukhova O. FGF23-Klotho signaling axis in the kidney. Bone. 2017;100:62-68. doi:10.1016/j.bone.2016.09.010 6. Data on file. Kyowa Kirin Cares Copay Utilization. Kyowa Kirin, Inc.; 2024.

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COMM-US-CRY-0779 June 2026