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

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Dosage and administration

Adult dosing schedule and administration for CRYSVITA® (burosumab-twza)

How to initiate treatment using the recommended starting dosage for adults with XLH.

Recommended starting dosage for adult patients (≥18 years of age)1

1 mg/kg of
body weight

rounded to the nearest 10 mg

(up to a maximum dose of 90 mg)

administered
every 4 weeks

CRYSVITA
starting dosage
given every

4

weeks1

CRYSVITA should be administered by a healthcare professional.1

Ready-to-use subcutaneous injection that comes in 3 strengths1:

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

The maximum volume of CRYSVITA per injection is
1.5 mL. If multiple injections are required, administer at different injection sites.1

You may need to adjust your patient's dosage for CRYSVITA if their serum phosphorus levels are not within the normal range1

  • CRYSVITA dosage may be decreased at any time for elevated serum phosphorus
  • After the initial 3 months of treatment, CRYSVITA dosing may be adjusted by modifying both the dose and dosing frequency (from every 4 weeks to every 2 weeks) to maintain serum phosphorus within the normal range

For additional details on how and when to monitor serum phosphorus and adjust the dosage for CRYSVITA, please see the Dosage adjustment section below.

A silhouette of a person indicating areas for injection in the front and back of the body

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

Before initiating treatment

Preparing your adult patients for CRYSVITA

Before initiating CRYSVITA1

  • Have your patient discontinue oral phosphate and/or active vitamin D analogs (eg, calcitriol, paricalcitol, doxercalciferol, calcifediol) 1 week prior
  • Fasting serum phosphorus concentration should be below the reference range for age
  • In patients at high risk for hypercalcemia (eg, pre-existing hyperparathyroidism, prolonged immobilization, dehydration, hypervitaminosis D, or renal impairment), assess serum calcium and parathyroid hormone levels
CRYSVITA® (burosumab-twza) injection 10, 20, 30 mg/mL vials
After initiating treatment

Assessing fasting serum phosphorus during CRYSVITA treatment for adults with XLH

The starting dosage of CRYSVITA is administered every 4 weeks for the first 3 months.1

After initiation of treatment with CRYSVITA, assess fasting serum phosphorus on a monthly basis, measured 2 weeks post-dose, for the first 3 months of treatment, and thereafter as appropriate.1

Monitor and adjust dose based on serum phosphorus levels1

If serum phosphorus is within the normal range, continue with the same dose. If serum phosphorus is not within the normal range, follow the Dosage adjustment instructions below.

Dosage adjustments

Adjust CRYSVITA dosage for adults with XLH to help maintain serum phosphorus within the normal range1

A calendar date with a star in the middle

When making dosage adjustments for your patients, take note of the following1:

  • CRYSVITA dosage may be decreased at any time for elevated serum phosphorus
  • CRYSVITA dosage may be increased after initial 3 months of treatment to maintain serum phosphorus within the normal range
  • Reassess fasting serum phosphorus level 2 weeks after dosage adjustment
  • Do not adjust CRYSVITA dosage more frequently than every 4 weeks

Increasing CRYSVITA dosing

If serum phosphorus is below the normal range after the first 3 months of treatment1:

  • Patients may be transitioned to a CRYSVITA dosage of 0.5 mg/kg, not to exceed 90 mg, once every 2 weeks
  • If further dosage increase is needed after 4 weeks of CRYSVITA dosed at 0.5 mg/kg every 2 weeks, the CRYSVITA dosage can be increased to 1 mg/kg, not to exceed 90 mg, administered every 2 weeks

Decreasing CRYSVITA dosing

If fasting serum phosphorus is above the normal range1:

  • Withhold the next dose and reassess the fasting serum phosphorus level after 4 weeks
  • The patient must have fasting serum phosphorus below the normal range to reinitiate CRYSVITA

Once fasting serum phosphorus is below the normal range1:

  • Reinitiate CRYSVITA at approximately half the previous dose
  • Reassess serum phosphorus 2 weeks after any change in dose
  • If the level remains below the normal range after the reinitiation dose, the dose can be adjusted as needed
Additional considerations

Additional considerations for dosage and administration of CRYSVITA for adults with XLH

When treating your patients with CRYSVITA, consider the following1:

  • CRYSVITA should be administered via subcutaneous injection only
  • Visually inspect CRYSVITA for particulate matter and discoloration prior to administration. Do not use if the solution is discolored or cloudy or if the solution contains any particles or foreign particulate matter
  • If a patient misses a dose, have the patient resume CRYSVITA as soon as possible at the prescribed dose. To avoid missed doses, treatments may be administered 3 days on either side of the scheduled treatment date
  • Monitor serum calcium and parathyroid hormone levels in patients at high risk for hypercalcemia before and during treatment

Have questions about biochemical reference ranges?

Check with the testing laboratory for specific definitions, parameters, and normal ranges. Your CRYSVITA representative can also provide resources on biochemical markers in XLH, including serum phosphorus.

Contact a rep

Connect with Kyowa Kirin Cares to help your adult patients prescribed CRYSVITA with their treatment journey

Patient access & support
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.

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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.

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.

Reference:

  • 1. CRYSVITA (burosumab-twza). US Prescribing Information. Kyowa Kirin, Inc.; April 2026.

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COMM-US-CRY-0778 June 2026