Active Ingredient: Burosumab
Burosumab is indicated for the treatment of FGF23-related hypophosphataemia in tumour-induced osteomalacia associated with phosphaturic mesenchymal tumours that cannot be curatively resected or localised in children and adolescents aged 1 to 17 years and in adults.
For this indication, competent medicine agencies globally authorize below treatments:
For:
Subcutaneous, 0.4 milligrams burosumab per kilogram of body weight, once every 2 weeks. The maximum allowed total dose is 2 milligrams burosumab per kilogram of body weight every 2 weeks.
The posology in children has been determined from pharmacokinetic modelling and simulation.
The recommended starting dose for children aged 1 to 12 years is 0.4 mg/kg of body weight, given every 2 weeks. Doses should be rounded to the nearest 10 mg. The maximum dose is 90 mg.
If serum phosphate is below the reference range for age, the dose may be increased in a stepwise manner. Doses should be increased by an initial increment of 0.6 mg/kg with subsequent increments, depending on patient’s response to treatment, of 0.5 mg/kg (up to a maximum dose of 2.0 mg/kg), rounding the amount as described above, up to a maximum dose of 90 mg, given every 2 weeks. Fasting serum phosphate should be measured 2 weeks after dose adjustment. Burosumab should not be adjusted more frequently than every 4 weeks.
For all paediatric patients, 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 and thereafter as appropriate. Fasting serum phosphate should also be measured 2 weeks after any dose adjustment. If fasting serum phosphate is within the reference range for age, the same dose should be maintained.
If serum phosphate is above the reference range for age, the next dose should be withheld and the fasting serum phosphate level reassessed in 2 weeks. Once serum phosphate is below the reference range for age, treatment may be restarted at half the previous dose in rounding the amount as described above. The fasting serum phosphate level should be assessed 2 weeks after the dose adjustment. If the level remains below the reference range for age after the re-started dose, the dose can be further adjusted.
If a patient undergoes treatment of the underlying tumour (i.e., surgical excision or radiation therapy) burosumab treatment should be interrupted.
Following completion of the treatment of the underlying tumour, serum phosphate should be reassessed before reinitiating treatment with burosumab. Burosumab treatment should be resumed at the patient’s original starting dose if serum phosphate level remains below the lower end of the normal reference range. Follow the recommended dose adjustment outlined above to maintain serum phosphate level within the normal reference range for age.
For all patients with TIO, treatment should be discontinued if the treating physician considers that no meaningful improvement in biochemical or clinical markers of response are observed, despite the maximum dose being administered.
To decrease the risk for ectopic mineralisation, it is recommended that fasting serum phosphate is targeted in the lower end of the normal reference range for age.
Treatments may be administered 3 days either side of the scheduled treatment date if needed for practical reasons. If a patient misses a dose, burosumab should be resumed as soon as possible at the prescribed dose.
Burosumab should be injected in the arm, abdomen, buttock or thigh.
Injections sites should be rotated and carefully monitored for signs of potential reactions.
For:
Subcutaneous, 0.3 milligrams burosumab per kilogram of body weight, once every 2 weeks.
The recommended starting dose for adolescents aged 13 to 17 years is 0.3 mg/kg of body weight, given every 2 weeks. Doses should be rounded to the nearest 10 mg. The maximum dose is 180 mg.
If serum phosphate is below the reference range for age, the dose may be increased in a stepwise manner. Doses should be increased by an initial increment of 0.3 mg/kg with subsequent increments of between 0.2 mg/kg – 0.5 mg/kg (dose increment dependent on the patient’s serum phosphate response to treatment), rounding the amount as described above, up to a maximum dose of 2.0 mg/kg (maximum dose 180 mg), given every 2 weeks. Fasting serum phosphate should be measured 2 weeks after dose adjustment. Burosumab should not be adjusted more frequently than every 4 weeks.
For all paediatric patients, 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 and thereafter as appropriate. Fasting serum phosphate should also be measured 2 weeks after any dose adjustment. If fasting serum phosphate is within the reference range for age, the same dose should be maintained.
If serum phosphate is above the reference range for age, the next dose should be withheld and the fasting serum phosphate level reassessed in 2 weeks. Once serum phosphate is below the reference range for age, treatment may be restarted at half the previous dose in rounding the amount as described above. The fasting serum phosphate level should be assessed 2 weeks after the dose adjustment. If the level remains below the reference range for age after the re-started dose, the dose can be further adjusted.
At 18 years of age the patient should convert to the adult dose and dosing regimen as outlined below.
If a patient undergoes treatment of the underlying tumour (i.e., surgical excision or radiation therapy) burosumab treatment should be interrupted.
Following completion of the treatment of the underlying tumour, serum phosphate should be reassessed before reinitiating treatment with burosumab. Burosumab treatment should be resumed at the patient’s original starting dose if serum phosphate level remains below the lower end of the normal reference range. Follow the recommended dose adjustment outlined above to maintain serum phosphate level within the normal reference range for age.
For all patients with TIO, treatment should be discontinued if the treating physician considers that no meaningful improvement in biochemical or clinical markers of response are observed, despite the maximum dose being administered.
To decrease the risk for ectopic mineralisation, it is recommended that fasting serum phosphate is targeted in the lower end of the normal reference range for age.
Treatments may be administered 3 days either side of the scheduled treatment date if needed for practical reasons. If a patient misses a dose, burosumab should be resumed as soon as possible at the prescribed dose.
Burosumab should be injected in the arm, abdomen, buttock or thigh.
Injections sites should be rotated and carefully monitored for signs of potential reactions.
For:
Subcutaneous, 0.3 milligrams burosumab per kilogram of body weight, once every 4 weeks. The maximum allowed total dose is 2 milligrams burosumab per kilogram of body weight every 4 weeks.
The recommended starting dose for adults is 0.3 mg/kg body weight, rounded to the nearest 10 mg, given every 4 weeks.
After initiation of treatment with burosumab, fasting serum phosphate should be measured 2 weeks after each dose for the first 3 months of treatment, and thereafter as appropriate. If serum phosphate is within the reference range, the same dose should be maintained.
If serum phosphate is below the reference range, the dose may be increased in a stepwise manner. Doses should be increased by an initial increment of 0.3 mg/kg, with subsequent increments of between 0.2 mg/kg – 0.5 mg/kg (dose dependent on the patient’s response to treatment), up to a maximum dose of 2.0 mg/kg (maximum dose 180 mg), given every 4 weeks. Fasting serum phosphate should be measured 2 weeks after dose adjustment.
For patients whose serum phosphate still remains below the reference range, despite providing the maximum dose every 4 weeks, the previous dose may be divided and given every 2 weeks, with incremental increases as required, as outlined above, up to a maximum dose of 2.0 mg/kg every 2 weeks (maximum dose 180 mg).
If serum phosphate is above the reference range, the next dose should be withheld and the fasting serum phosphate level reassessed in 2 weeks. The patient must have serum phosphate below the reference range before restarting burosumab. Once serum phosphate is below the reference range, treatment may be restarted at approximately half the previous dose, administered every 4 weeks. Serum phosphate should be reassessed 2 weeks after any change in dose.
If the level remains below the reference range after the re-started dose, the dose can be further adjusted.
If a patient undergoes treatment of the underlying tumour (i.e., surgical excision or radiation therapy) burosumab treatment should be interrupted.
Following completion of the treatment of the underlying tumour, serum phosphate should be reassessed before reinitiating treatment with burosumab. Burosumab treatment should be resumed at the patient’s original starting dose if serum phosphate level remains below the lower end of the normal reference range. Follow the recommended dose adjustment outlined above to maintain serum phosphate level within the normal reference range for age.
For all patients with TIO, treatment should be discontinued if the treating physician considers that no meaningful improvement in biochemical or clinical markers of response are observed, despite the maximum dose being administered.
To decrease the risk for ectopic mineralisation, it is recommended that fasting serum phosphate is targeted in the lower end of the normal reference range for age.
Treatments may be administered 3 days either side of the scheduled treatment date if needed for practical reasons. If a patient misses a dose, burosumab should be resumed as soon as possible at the prescribed dose.
Burosumab should be injected in the arm, abdomen, buttock or thigh.
Injections sites should be rotated and carefully monitored for signs of potential reactions.
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