What is Crysvita (burosumab) and what does it treat?
Crysvita is the brand name for burosumab, an antibody used to treat certain forms of X-linked hypophosphatemia (XLH) and tumor-induced osteomalacia (TIO). It works by targeting FGF23, a hormone that drives phosphate loss in the urine. By inhibiting FGF23, burosumab helps raise blood phosphate levels and supports bone mineralization. [1][2]
Which patients does it cover (XLH vs. tumor-induced osteomalacia)?
For XLH, Crysvita is used in both children and adults. For tumor-induced osteomalacia, it is used for people with the condition when tumors are not removable or when tumors cannot be found/fully addressed. Coverage and age criteria vary by country and regulatory approval. [1][2]
How is Crysvita given, and what monitoring is required?
Crysvita is given by injection (subcutaneous). Because it affects phosphate levels, clinicians monitor serum phosphate and adjust dosing based on response and lab results. People also get periodic monitoring of calcium/phosphate balance and overall mineralization and bone health as part of ongoing care. [1][2]
How fast does it work, and how is the dose adjusted?
After starting treatment, serum phosphate is checked to see whether levels move into the desired range. Dosing is then adjusted to maintain effectiveness while minimizing the risk of abnormal calcium/phosphate balance. Specific titration schedules depend on age, indication, and prior treatments. [1][2]
What side effects do patients ask about most?
Commonly reported issues with burosumab/Crysvita include injection-site reactions and changes in blood phosphate levels. Clinicians also watch for complications related to mineral balance (for example, abnormal calcium/phosphate handling and related issues). The exact list and frequency come from the local prescribing information for your market. [1][2]
What happens if someone misses a dose?
If a scheduled dose is missed, the typical approach is to contact the prescribing clinician for guidance on when to take the next dose and how to adjust monitoring. Because timing matters for keeping phosphate in range, patients should not simply double doses without medical advice. [1][2]
Is Crysvita made by Ultragenyx? Who owns/markets it?
Crysvita is associated with Ultragenyx as a company involved in the product’s development/commercialization in some markets. The drug is burosumab (the active ingredient name), and the manufacturer/marketer details can differ by country and regulatory structure. [1][2]
Where to find the most reliable details for your country
Dosing schedules, age eligibility, and safety guidance can differ by regulator. The most accurate source is the official prescribing information and/or the product page for your country’s health authority or the brand’s official site. [1][2]
Sources:
[1] https://www.cryvita.com/
[2] https://www.ema.europa.eu/en/medicines/human/EPAR/crysvita