Microplastics and Misinformation: What Science Really Says
November 12, 2025
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Brand Name :
Crysvita, burosumab-twza
Synonyms :
burosumab
Class :
Monoclonal Antibodies, Endocrine
Brand Name :
Crysvita, burosumab-twza
Synonyms :
burosumab
Class :
Monoclonal Antibodies, Endocrine
Dosage forms & Strengths:
Adult:
Solution for Injection:
10 mg/ml
20 mg/ml
30 mg/ml
Solution for Injection:
10 mg/ml
20 mg/ml
30 mg/ml
Refer to the adult dosing
may have an increased adverse effect when combined with burosumab
may increase the toxic effect of Vitamin D analogs
Actions and Spectrum:
Actions:
burosumab binds to and inhibits the activity of fibroblast growth factor 23 (FGF23), a hormone that regulates phosphorus metabolism in the body. By blocking the action of FGF23, burosumab increases phosphorus levels in the blood and bones, helping to correct the underlying deficiency in XLH.
Spectrum:
burosumab is effective in reducing symptoms and improving bone mineralization in patients with XLH. In clinical trials, treatment with burosumab has been associated with increases in phosphorus levels, decreases in levels of parathyroid hormone (PTH), and improvements in markers of bone health, such as bone density and growth.
Frequency Defined
10%:
Headache (8-73%)
Vomiting (46-48%)
Pyrexia (44-62%)
Injection site reaction (23-67%)
Toothache (15-23%)
Myalgia (8-17%)
A Tooth abscess (15-23%)
Rash (8-27%)
Hypersensitivity (22%)
Dizziness (15%)
Pain in extremities (23-46%)
Vitamin D decreased (15-37%)
1-10%:
Dizziness (10%)
Blood phosphorus increased (6%)
Constipation (9%)
Contraindication/Caution:
Contraindications:
burosumab should not be used in patients with a known hypersensitivity to burosumab or any of its components.
Cautions:
Caution should be used in patients with severe hypersensitivity, like anaphylaxis, to other monoclonal antibodies.
Pregnancy consideration:
No data is available regarding the use of the drug during pregnancy.
Breastfeeding warnings:
No data is available regarding the excretion of the drug in breast milk.
Pregnancy category:
Category A: well-controlled and satisfactory studies do not show risk to the fetus in the first/later trimester.
Category B: there was no evidence of risk to the fetus in animal studies, and there were not enough studies on pregnant women.
Category C: there was evidence of risk of adverse effects in animal reproduction studies, and no adequate evidence in human studies must take care of potential risks in pregnant women.
Category D: adequate data available with sufficient evidence of human fetal risk from various platforms, but despite the potential risk, and used only in emergency cases for potential benefits.
Category X: Drugs listed in this category outweigh the risks over benefits. Hence these categories of drugs need to be avoided by pregnant women.
Category N: No data is available for the drug under this category.
Pharmacology:
burosumab works by binding to and blocking the activity of a protein called fibroblast growth factor 23 (FGF23). It is overproduced in XLH and results in excessive phosphate wasting. And reduces levels of active vitamin D. By inhibiting FGF23, burosumab increases phosphate reabsorption in the kidney. It allows for more effective vitamin D activation, increases serum phosphate levels, and improves bone health in XLH patients.
Pharmacodynamics:
burosumab is a fully human monoclonal antibody that binds to and neutralizes the activity of sclerostin, a protein that regulates bone formation. Sclerostin is an inhibitor of bone formation, and increased levels of sclerostin are associated with decreased bone density and an increased risk of fractures. By neutralizing sclerostin, burosumab stimulates bone formation and increases bone density. It is a promising treatment option for conditions associated with low bone density. These conditions include osteogenesis imperfecta (OI) and X-linked hypophosphatemia (XLH).
Pharmacokinetics:
Pharmacokinetics of burosumab have shown that the antibody is well-tolerated and exhibits linear pharmacokinetics over the dose range studied, with no accumulation after repeated dosing.
Absorption
Peak plasma time is 8-11 days
The steady-state trough is 5.8 mcg/mL
Distribution
The volume of distribution is 8L
Metabolism
burosumab is expected to catabolize into smaller peptides and amino acids
Elimination
The half-life of the drug is 19 days
The rate of clearance is 0.290 L/day
Administration:
burosumab is administered as a subcutaneous injection. The recommended dosing regimen for burosumab is based on the patient’s weight and the treatment condition. The recommended starting dose for adults is 1 mg/kg once every 4 weeks. Adjust the dose based on the patient’s response to treatment and individual needs. The drug is stored under refrigeration.
Patient information leaflet
Generic Name: burosumab
Pronounced: bur-OH-sue-mab
Why do we use burosumab?
burosumab is a medication used to treat X-linked hypophosphatemia (XLH), a rare genetic disorder that affects bone health. By blocking FGF23, burosumab helps increase phosphate levels in the blood and improve bone health in people with XLH.
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