CRYSVITA (burosumab-twza)
OFFICE ADMINISTRATION
Indications for Prior Authorization:
- Treatment of X-linked hypophosphatemia (XLH) in adult and pediatric patients 1 year of age and older
Patients must meet the following criteria for the indication(s) above:
- Patient is 1 year of age or older, AND
- Diagnosis of X-linked hypophosphatemia (XLH), AND
- Prescribed by or in consultation with an endocrinologist or nephrologist, AND
- Patient has a baseline serum phosphorus level below normal range for age, AND
- Patient has a baseline tubular reabsorption of phosphate corrected for glomerular filtration rate that was below the normal range for age and gender, AND
- Patient will not use oral phosphate and active Vitamin D analogs, AND
- Patient does not have severe renal impairment or end stage renal disease
Dosing:
- Pediatric XLH:
- Starting dose: 0.8 mg/kg of body weight rounded to the nearest 10 mg, administered every 2 weeks. Minimum dose 10 mg up to a maximum dose of 90 mg.
- Do not adjust Crysvita more frequently than every 4 weeks.
- Dose may be increased up to approximately 2 mg/kg (maximum 90 mg), administered every 2 weeks to achieve normal serum phosphorus
- Adult XLH:
- Dose regimen: 1 mg/kg body weight rounded to the nearest 10 mg up to a maximum dose of 90 mg administered every 4 weeks
Approval:
- 1 year
Last review date: April 30, 2019