CRYSVITA

The following pharmacokinetic parameters were observed in patients with XLH administered the approved recommended starting dosage based on a 70 kg patient, unless otherwise specified. Based on the population PK analysis, the PK characteristics of burosumab-twza were similar between patients with XLH and TIO. Burosumab-twza exhibited linear pharmacokinetics following SC injections within the dose range of 0.1 to 1 mg/kg (0.08 to 0.8 times the maximum approved recommended dosage based on a 70 kg p...

14.1 Pediatric X-linked Hypophosphatemia CRYSVITA has been evaluated in three studies enrolling a total of 126 pediatric patients with XLH.

Study 1(NCT 02915705) is a 64-week randomized, open-label study in 61 pediatric XLH patients, 1 to 12 years old that compared treatment with CRYSVITA to active control (oral phosphate and active vitamin D). At time of first dose the mean age of patients was 6.3 years and 44% were male. All patients had radiographic evidence of rickets at baseline, with an RSS score of ≥ 2.0 and had received oral phosphate and active vitamin D analogs for a mean (SD) durat...

The following adverse reactions are described below and elsewhere in the labeling: Hypersensitivity [see Warnings and Precautions (5.1) ] Hyperphosphatemia and Risk of Nephrocalcinosis [see Warnings and Precautions (5.2) ] Hypercalcemia [see Warnings and Precautions (5.3) Injection Site Reactions [see Warnings and Precautions (5.4) ] Most common adverse reactions (≥25% in the CRYSVITA group and > Active Control) in pediatric XLH patients are: pyrexia, injection site reaction, cough, vomiting, pa...

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 [see Warnings and Precautions (5.2) and Drug Interactions (7.1) ] . When serum phosphorus is within or above the normal range for age [see Warnings and Precautions (5.2) ] . In patients with severe ren...

Hypersensitivity : Discontinue CRYSVITA if serious hypersensitivity reactions occur and initiate appropriate medical treatment. ( 5.1 ) Hyperphosphatemia and 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. ( 5.2 , 6.1 ) Hypercalcemia : Increases in serum calcium been reported. Monitor serum calcium and parathyroid hormone levels in patients at high risk for hypercalcemia before ...

7 DRUG INTERACTIONS 7.1 Oral Phosphate and Active Vitamin D Analogs Concomitant use of CRYSVITA with oral phosphate and/or active vitamin D analogs will increase phosphate concentrations greater than expected with CRYSVITA alone. This increase may result in hyperphosphatemia which can induce nephrocalcinosis. Concomitant use of CRYSVITA with oral phosphate and/or active vitamin D analogs is contra...