Successful Burosumab Treatment in an Adult Patient with X-Linked Hypophosphatemia and Chronic Kidney Disease Stage 3b.
Calcif Tissue Int
; 114(3): 310-314, 2024 03.
Article
in En
| MEDLINE
| ID: mdl-38195892
ABSTRACT
X-linked hypophosphatemic rickets (XLH) is a genetic cause of renal hypophosphatemia due to inactivation of the PHEX gene, with an inappropriate concentration of fibroblast growth factor 23 (FGF23). Burosumab, an anti-FGF23 monoclonal antibody, is a validated treatment for XLH, but its use in patients with chronic kidney disease (CKD) has not been validated. A 61-year-old man with XLH developed CKD during follow-up. Conventional treatment (phosphate salts and active vitamin D analogs) was poorly tolerated. Treatment with burosumab was decided at a multi-professional meeting. Before burosumab initiation, his measured glomerular filtration rate was 44 mL/min/1.73 m2 defining CKD stage 3b and intact FGF23 concentration was very high (4496.0 ng/mL, N 22.7-93.1) due to both XLH and CKD. Severe hypophosphatemia was observed after the two first injections of burosumab at usual doses (1 mg/kg monthly) and concomitant discontinuation of the conventional treatment. After increasing the dose and reducing the interval between doses (1.3 mg/kg every three weeks) from the third injection, serum phosphate concentration normalized and remained around the lower limit of the normal range. A local cutaneous reaction was observed just after the second injection, but did not recur. We report for the first time the efficacy and good short-term tolerance of burosumab in a patient with XLH and CKD, subject to a higher dosage aimed at achieving a phosphatemia at the lower limit of the normal range.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Hypophosphatemia
/
Renal Insufficiency, Chronic
/
Familial Hypophosphatemic Rickets
/
Antibodies, Monoclonal, Humanized
Limits:
Adult
/
Humans
/
Male
/
Middle aged
Language:
En
Journal:
Calcif Tissue Int
/
Calcif. tissue int
/
Calcified tissue international
Year:
2024
Document type:
Article
Affiliation country:
France
Country of publication:
United States