European Medicines Agency's (EMA) Committee for Medicinal Products for Human
Use (CHMP) has granted conditional marketing authorization for burosumab for
the treatment of a rare bone disease called X-linked hypophosphatemia (XLH).
- Burosumab is a monoclonal antibody that acts against
the fibroblast growth factor 23 (FGF23)
- It has been granted conditional approval for the
treatment of X-linked hypophosphatemia from the European Union
- Further studies are required before its use can be
established for the condition
now be used in the European Union in children over 1 year of age and in
adolescents with growing skeletons and with radiological evidence of the
presence of the condition. Currently, the US Food and Drug Administration (FDA)
is also reviewing the drug for its use in the rare condition.
is a monoclonal antibody directed against the hormone fibroblast growth factor
FGF23 prevents the
reabsorption of phosphate by the kidney. It also plays a role in the regulation
of vitamin D. An excess of FGF23 results in excess loss of phosphate and
reduces its blood level. Burosumab increases the reabsorption of phosphate from
the kidney thereby increasing the blood phosphate levels. It also increases the
production of vitamin D, which in turn increases the absorption of calcium and
phosphate from the intestine, thereby increasing their blood levels.
‘Burosumab is a monoclonal antibody that has recently received conditional approval in the European Union for the treatment of X-linked hypophosphatemia.’
benefits of burosumab in X-linked hypophosphatemia in increasing blood
phosphate levels and improving rickets have been
demonstrated in two small studies.
One study was conducted on 53 children
in the age group of 5 to 12 years with the disorder, while the second study was
conducted on 13 children between the ages of 1 to 4 years. Side effects noted
were reactions at the site of the injection, headache and pain in the
Burosumab is also being
evaluated for the treatment of tumor-induced osteomalacia, another condition
that weakens bones. Tumor-induced osteomalacia occurs in patients with benign
tumors and is associated with high FGF23 levels.
hypophosphatemia (XLH) is a rare inherited bone disorder that arises due loss
of excess phosphate through the urine. This results in low levels of
phosphate in the blood, which in turn draws phosphate from the bone, thereby
weakening it and resulting in rickets. The patient has a high level of the
Children with XLH suffer
from bone and teeth pain, along with bone deformities that include bent legs
and short stature. Other features include a waddling gait, muscle weakness,
pseudofractures, narrowing of the spinal cord, abnormal bone growth at the
attachment of tendons or ligaments to bone (enthesopathy) and osteoarthritis
Treatment includes the intake of oral phosphate and vitamin D, which treat the
symptoms but do not address the underlying problem.
- Hereditary hypophosphatemic rickets - (https://ghr.nlm.nih.gov/condition/hereditary-hypophosphatemic-rickets)
- FGF23 Gene - (https://ghr.nlm.nih.gov/gene/FGF23)