Premium Nahrungsergänzungsmittel | artgerecht

Burosumab: Mechanism, Uses & Side Effects

Burosumab is a monoclonal antibody used to treat X-linked hypophosphatemia. It inhibits FGF23 and helps restore normal phosphate levels in the blood.

Regular tips about health Regular tips about health

Things worth knowing about "Burosumab"

Burosumab is a monoclonal antibody used to treat X-linked hypophosphatemia. It inhibits FGF23 and helps restore normal phosphate levels in the blood.

What is Burosumab?

Burosumab is a fully human monoclonal antibody approved for the treatment of X-linked hypophosphatemia (XLH), a rare inherited disorder in which the body cannot maintain adequate phosphate levels in the blood. This leads to rickets, bone deformities, impaired growth in children, and chronic musculoskeletal pain in adults. Burosumab is marketed under the brand name Crysvita and is approved for both children and adults.

Indications

Burosumab is approved for:

X-linked hypophosphatemia (XLH) in children aged one year and older and in adults
Tumor-induced osteomalacia (TIO) in adults where the causative tumor cannot be completely resected or localized

Mechanism of Action

In XLH and TIO, the protein FGF23 (Fibroblast Growth Factor 23) is excessively elevated in the bloodstream. Under normal conditions, FGF23 plays a role in regulating phosphate excretion by the kidneys. When FGF23 levels are too high, the kidneys excrete too much phosphate in the urine (hyperphosphaturia), leading to chronically low blood phosphate levels (hypophosphatemia) and impaired vitamin D activation.

Burosumab binds directly and selectively to FGF23, blocking its biological activity. This results in:

Increased phosphate reabsorption in the kidneys
Normalization of serum phosphate levels
Increased activation of vitamin D (to 1,25-dihydroxyvitamin D)
Improved bone mineralization and healing of rickets or osteomalacia

Dosage and Administration

Burosumab is administered as a subcutaneous injection (under the skin). The dose is based on body weight and serum phosphate levels:

Children (XLH): Typically every 2 weeks, starting dose of 0.4 mg/kg body weight
Adults (XLH): Typically every 4 weeks, starting dose of 1.0 mg/kg body weight
Adults (TIO): Dosing adjusted individually based on phosphate levels, given every 2 or 4 weeks

The dose is regularly adjusted to maintain serum phosphate within the target range. Concomitant use of oral phosphate supplements or active vitamin D analogues should be avoided during burosumab therapy, as this increases the risk of hyperphosphatemia and nephrocalcinosis.

Side Effects

Burosumab is generally well tolerated. The most commonly reported side effects include:

Injection site reactions (redness, swelling, pain)
Headache
Dizziness
Tooth pain or dental abscesses
Elevated blood phosphate levels (hyperphosphatemia)
Vitamin D imbalance
Rash or itching

In rare cases, ectopic mineralization (unwanted calcium deposits in soft tissues or kidneys) may occur. Regular laboratory monitoring is therefore required throughout the course of treatment.

Treatment Context and Clinical Significance

Before burosumab became available, the standard treatment for XLH consisted of high-dose oral phosphate supplements combined with active vitamin D analogues (calcitriol or alfacalcidol). This regimen was associated with significant side effects, including diarrhea, nephrocalcinosis, and secondary hyperparathyroidism. Burosumab, by contrast, targets the underlying disease mechanism directly and has demonstrated superior efficacy in clinical trials, including improved healing of rickets, reduction in bone pain, and better physical function.

Burosumab is classified as a biologic therapy and belongs to the monoclonal antibody drug class. It was developed by Kyowa Kirin and received approval from the European Medicines Agency (EMA) in 2018.

References

European Medicines Agency (EMA): Crysvita (Burosumab) - European Public Assessment Report (EPAR), 2018. Available at: https://www.ema.europa.eu
Insogna KL et al. - A Randomized, Double-Blind, Placebo-Controlled, Phase 3 Trial Evaluating the Efficacy of Burosumab in Adults with XLH. Journal of Bone and Mineral Research, 2018.
Carpenter TO et al. - Burosumab Therapy in Children with X-Linked Hypophosphatemia. New England Journal of Medicine, 2018; 378(21): 1987-1998.

Building Blocks for a Healthy Life

As an integrated manufacturer, we develop & produce evidence-based, patented, and non-patented formulations. We work exclusively with plant and natural extracts according to the strictest purity & quality standards.
The combination of science & modern technology with the laws of nature creates solutions consistently tailored to humans – for the highest good: health.