8 mg/kg of body weight rounded to the nearest 10 mg, administered every two weeks. The minimum starting dose is 10 mg up to a maximum dose of 90 mg. 2 ) Dose may be increased up to approximately 2 mg/kg (maximum 90 mg), administered every two weeks to achieve normal serum phosphorus.
2 ) Adult XLH: Dose regimen is 1 mg/kg body weight rounded to the nearest 10 mg up to a maximum dose of 90 mg administered every four weeks. 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 two weeks.
5 mg/kg every four weeks. Dose may be increased up to 2 mg/kg not to exceed 180 mg, administered every two weeks. g. 3) ] . Prior to starting CRYSVITA, fasting serum phosphorus concentration should be below the reference range for age [see Contraindications (4) ].
3) ] . CRYSVITA is administered by subcutaneous injection and should be administered by a healthcare provider. 5 mL. If multiple injections are required, administer at different injection sites. 2 Recommended Dosage for Pediatric Patients with X-linked Hypophosphatemia (6 months to less than 18 years of age) For patients who weigh less than 10 kg, the recommended starting dosage is 1 mg/kg of body weight, rounded to the nearest 1 mg, administered every two weeks.
8 mg/kg of body weight, rounded to the nearest 10 mg, administered every two weeks. The minimum starting dose is 10 mg up to a maximum dose of 90 mg. After initiation of treatment with CRYSVITA, measure fasting serum phosphorus every 4 weeks for the first 3 months of treatment, and thereafter as appropriate.
If serum phosphorus is above the lower limit of the reference range for age and below 5 mg/dL, continue treatment with the same dose. Follow dose adjustment schedule below to maintain serum phosphorus within the reference range for age.
Dose Adjustment Reassess fasting serum phosphorus level 4 weeks after dose adjustment. Do not adjust CRYSVITA more frequently than every 4 weeks. 5 mg/kg, rounded to the nearest 1 mg, administered every two weeks. If additional dose increases are needed, the dose may be increased to the maximum dose of 2 mg/kg, rounded to the nearest 1 mg, administered every two weeks.
For patients who weigh 10 kg or greater, if serum phosphorus is below the reference range for age, the dose may be increased stepwise up to approximately 2 mg/kg, administered every two weeks (maximum dose of 90 mg) according to the dosing schedule shown in Table 1.
Table 1:
XLH Pediatric Dose Schedule for Stepwise Dose Increase for Patients Weighing 10 kg or More Body Weight (kg) Starting Dose (mg) First Dose Increase to (mg) Second Dose Increase to (mg) 10 – 14 10 15 20 15 – 18 10 20 30 19 – 31 20 30 40 32 – 43 30 40 60 44 – 56 40 60 80 57 – 68 50 70 90 69 – 80 60 90 90 81 – 93 70 90 90 94 – 105 80 90 90 106 and greater 90 90 90 Dose Decrease: If serum phosphorus is above 5 mg/dL, withhold the next dose and reassess the 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. 5 mg/kg of body weight, rounded to the nearest 1 mg, administered every two weeks.
For patients who weigh 10 kg or more, restart CRYSVITA according to the dose schedule shown in Table 2.
Table 2:
XLH Pediatric Dose Schedule for Re-Initiation of Therapy for Patients Weighing 10 kg or More Previous Dose (mg) Re-Initiation Dose (mg) 10 5 15 10 20 10 30 10 40 20 50 20 60 30 70 30 80 40 90 40 After a dose decrease, reassess serum phosphorus level 4 weeks after the dose adjustment.
If the level remains below the reference range for age after the re-initiation dose, the dose can be adjusted as outlined under Dose Increase. 3 Recommended Dosage for Adult Patients with X-linked Hypophosphatemia (18 years of age and older) The recommended dosage regimen in adults is 1 mg/kg body weight, rounded to the nearest 10 mg up to a maximum dose of 90 mg, administered every four weeks.
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. If serum phosphorus is within the normal range, continue with the same dose.
Dose Decrease Reassess fasting serum phosphorus level 2 weeks after dose adjustment. Do not adjust CRYSVITA more frequently than every 4 weeks. If serum phosphorus is above the normal range, withhold the next dose and reassess the serum phosphorus level after 4 weeks.
The patient must have serum phosphorus below the normal range to be able to reinitiate CRYSVITA. Once serum phosphorus is below the normal range, treatment may be restarted at approximately half the initial starting dose up to a maximum dose of 40 mg every 4 weeks according to the dose schedule shown in Table 3.
Reassess serum phosphorus 2 weeks after any change in dose. 4 mg/kg body weight administered every 2 weeks, rounded to the nearest 10 mg, up to a maximum dose of 2 mg/kg not to exceed 180 mg, administered every 2 weeks. 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.
If serum phosphorus is within the reference range for age, continue with the same dose. Follow the dose adjustment schedule below to maintain serum phosphorus within the reference range for age. Dose Adjustment Reassess fasting serum phosphorus level 4 weeks after dose adjustment.
Do not adjust CRYSVITA more frequently than every 4 weeks. Dose Increase If serum phosphorus is below the reference range for age, the dose should be titrated in accordance with Table 4 up to the maximum dose of 2 mg/kg every 2 weeks.
The maximum dose should not exceed 180 mg. 5 mg/kg. Further dose increases to a maximum of 2 mg/kg not to exceed 180 mg, administered every 2 weeks should be calculated by the physician. Increase to (mg) 10 – 14 5 10 15 20 15 – 18 5 10 20 25 19 – 31 10 20 25 30 32 – 43 10 30 40 50 44 – 56 20 40 50 70 57 – 68 20 50 70 90 69 – 80 30 60 80 100 81 – 93 30 70 100 120 94 – 105 40 80 110 140 106 and greater 40 90 130 160 Dose Decrease If serum phosphorus is above the reference range for age, withhold the next dose and reassess the 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 for pediatrics.
After a dose decrease, reassess serum phosphorus level 4 weeks after the dose adjustment. If the level remains below the reference range for age after the re-initiation dose, the dose can be adjusted as outlined per Table 4 . , surgical excision or radiation therapy) CRYSVITA treatment should be interrupted and serum phosphorus reassessed after treatment has been completed.
CRYSVITA dose should be restarted at the patient's initiation dose if serum phosphorus remains below the lower limit of normal. Follow dose adjustment per Table 4 to maintain serum phosphorus within the reference range for age. 5 mg/kg body weight administered every 4 weeks, rounded to the nearest 10 mg, up to a maximum dose of 2 mg/kg not to exceed 180 mg, administered every 2 weeks.
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. If serum phosphorus is within the normal range, continue with the same dose.
Follow the dose adjustment schedule below to maintain serum phosphorus within the reference range. Dose Adjustment Reassess fasting serum phosphorus level 2 weeks after dose adjustment. Do not adjust CRYSVITA more frequently than every 4 weeks.
Dose Increase If serum phosphorus is below the normal range, the dose should be titrated in accordance with Table 5 up to the maximum dose of 2 mg/kg not to exceed 180 mg, administered every 2 weeks. For those individuals not reaching a serum phosphorus greater than the lower limit of the normal range, physicians may consider dividing total dose administered every 4 weeks and administering every 2 weeks.
Table 5:
TIO Dose Schedule Rounded to the nearest 10 mg. for Stepwise Do not adjust CRYSVITA more frequently than every 4 weeks. Dose Increase for Adults (18 years of age and older) Starting Dose First Dose Increase For those individuals not reaching a serum phosphorus greater than the lower limit of the normal range, physicians may consider dividing total dose administered every 4 weeks and administering every 2 weeks.
5 mg/kg every 4 weeks In patients with high body weight, if the calculated dose is greater than 180 mg every 4 weeks, move to a divided dose every 2 weeks. 5 mg/kg not to exceed 180 mg every 2 weeks Increase to: 2 mg/kg not to exceed 180 mg every 2 weeks Dose Decrease If serum phosphorus is above the normal range, withhold the next dose and reassess the 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 for adults.
After a dose decrease, reassess serum phosphorus level 2 weeks after the dose adjustment. If the level remains below the reference range after the re-initiation dose, the dose can be adjusted as outlined per Table 5 . , surgical excision or radiation therapy) CRYSVITA treatment should be interrupted and serum phosphorus reassessed after treatment has been completed.
CRYSVITA dose should be restarted at the patient’s initiation dose if serum phosphorus remains below the lower limit of normal. Follow dose adjustment per Table 5 to maintain serum phosphorus within the reference range. 6 Missed Dose 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. 7 25-Hydroxy Vitamin D Supplementation Monitor 25-hydroxy vitamin D levels. Supplement with cholecalciferol or ergocalciferol to maintain 25-hydroxy vitamin D levels in the normal range for age.
Do not administer active Vitamin D analogs during CRYSVITA treatment [see Contraindications (4) ]. 8 General Considerations for Subcutaneous Administration 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. If a given dose on a dosing day requires multiple vials of CRYSVITA, contents from two vials can be combined for injection. 5 mL. If multiple injections are required on a given dosing day, administer at different injection sites.
4) ] . Visually inspect CRYSVITA for particulate matter and discoloration prior to administration. 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.