Start treatment with CRYSVITA® as early as possible after diagnosis of XLH in suitable patients
Please refer to the Summary of Product Characteristics for full details before prescribing.
CRYSVITA is indicated for the treatment of XLH, in children and adolescents aged 1 to 17 years with radiographic evidence of bone disease, and in adults.1
CRYSVITA dosing is every 2 weeks in paediatric patients (children and adolescents aged 1–17 years)1
Dosing in children and adolescents is every 2 weeks.
The recommended starting dose is 0.8 mg/kg of body weight. All doses should be rounded to the nearest 10 mg. The maximum dose is 90 mg.
After initiating CRYSVITA, measure fasting serum phosphate:
- every 2 weeks for the first month of treatment
- every 4 weeks for the following 2 months
- thereafter as appropriate
If fasting serum phosphate is within the reference range for age, the same dose should be maintained.
It is recommended that fasting serum phosphate is targeted to the lower end of the normal reference range for age.
Oral phosphate and active vitamin D analogues (e.g. calcitriol) should be discontinued 1 week prior to initiation of CRYSVITA treatment. Vitamin D replacement or supplementation (with inactive forms) may be started or continued as per local guidelines under monitoring of serum calcium and phosphate.
CRYSVITA is dosed every 4 weeks in adult patients1
Dosing in adults is every 4 weeks.
The recommended starting dose in adults is 1.0 mg/kg of body weight, rounded to the nearest 10 mg up to a maximum dose of 90 mg, given every 4 weeks.
After initiation of treatment with burosumab, fasting serum phosphate should be measured:
- every 2 weeks for the first month of treatment
- every 4 weeks for the following 2 months
- thereafter as appropriate
Fasting serum phosphate should be measured 2 weeks after the previous dose of CRYSVITA. If serum phosphate is within the normal range, the same dose should be continued.
Oral phosphate and active vitamin D analogues (e.g. calcitriol) should be discontinued 1 week prior to initiation of CRYSVITA treatment. Vitamin D replacement or supplementation (with inactive forms) may be started or continued as per local guidelines under monitoring of serum calcium and phosphate.
Calculation for starting dose
Dose increase (children and adolescents aged 1 to 17 years)1
If fasting serum phosphate is below the reference range for age, the dose may be increased stepwise by 0.4 mg/kg up to a maximum dose of 2 mg/kg (maximum dose of 90 mg).
Reassess fasting serum phosphate level 4 weeks after each dose adjustment.
Dose decrease (children and adolescents aged 1 to 17 years)1
If fasting serum phosphate is above the reference range for age, withhold the next dose and reassess fasting serum phosphate within 4 weeks.
Fasting serum phosphate must be below the reference range for age to restart CRYSVITA at approximately half of the previous dose, rounding the amount as described above.
Reassess fasting serum phosphate level 4 weeks after dose adjustment.
Dose decrease (adults)1
If serum phosphate is above the upper limit of normal range, the next dose should be withheld and the serum phosphate level reassessed within 2 weeks. The patient must have serum phosphate below the normal range before restarting burosumab. Once serum phosphate is below the normal range, treatment may be restarted at half the initial starting dose up to a maximum dose of 40 mg every 4 weeks. Serum phosphate should be reassessed 2 weeks after any change in dose.
Do not adjust CRYSVITA
more frequently than every 4 weeks
Missed or late dosing1
To avoid missed doses, treatments may be administered 3 days either side of the scheduled treatment date. If a patient misses a dose, resume CRYSVITA as soon as possible at the prescribed dose.
CRYSVITA should be administered subcutaneously by a healthcare professional1
Inject in the arm, abdomen, buttock or thigh.
The maximum volume of CRYSVITA per injection site is 1.5 mL. If more than 1.5 mL is required on a given dosing day, the total volume of medicinal product must be split and administered at two or more different injection sites.
Injection sites should be rotated and carefully monitored for signs of potential reactions.
Recommended monitoring schedule for CRYSVITA patients1
| Assessment | Frequency |
|---|---|
| Fasting serum phosphate† | |
| Month 1: Every 2 weeks | |
| Month 2-3: Every 4 weeks | |
| Thereafter: As appropriate | |
| Following dose adjustment: 4 weeks after | |
| Renal ultrasonography | |
| Year 1: At start of treatment and every 6 months | |
| Thereafter: Annually | |
| Plasma ALP, calcium, PTH and creatinine | |
| In children aged 1–2 years: Every 3 months, or as indicated | |
| In children >2 years and adults: Every 6 months, or as indicated | |
| Urine calcium and phosphate | Every 3 months |
†It is recommended that fasting serum phosphate is targeted at the lower end of the normal reference for age.
Contraindications, warnings and precautions1
- Hypersensitivity to the active substance or to any of the excipients (L-histidine, D-sorbitol E420, polysorbate 80, L-methionine, hydrochloric acid, 10% [for pH adjustment] and water for injections)
- Concurrent administration with oral phosphate, active vitamin D analogues
- Fasting serum phosphate above the normal range for age due to the risk of hyperphosphataemia
- Patients with severe renal impairment or end stage renal disease
- Safety and efficacy of CRYSVITA in children aged less than one year have not been established
- Co-administration of calcimimetic medicinal products* could potentially exacerbate hypocalcaemia
- CRYSVITA is not recommended during pregnancy and in women of childbearing potential not using contraception
- It is unknown whether CRYSVITA or its metabolites are excreted in human milk and a risk to newborns or infants cannot be ruled out. A discussion between the prescribing healthcare professional and patient should take place to make a decision whether to continue breastfeeding
*Agents that mimic the effect of calcium on tissues by activating the calcium receptor.
Store CRYSVITA away from light and in refrigerated conditions2
CRYSVITA is supplied as a clear to slightly opalescent, colourless to pale brownish-yellowish solution. The product is available as one single-dose vial per pack in the following strengths: 10, 20, and 30 mg/mL.
Store under refrigerated conditions at 2°C to 8°C in the original package to protect from light until use.
Do not freeze or shake before use. CRYSVITA should not be used after the expiry date which is stated on the package and label. Any unused medicinal product or waste material should be disposed of in accordance with local requirements.
