Vaisbich MH, de Cillo ACP, Silva BCC, DÁlva CB, de Carvalho ÉH, de Almeida JMCM, Marques LLM, Ribeiro M, da Silva MBM, de Medeiros PFV, Mendes PH. Real-world data of Brazilian adults with X-linked hypophosphatemia (XLH) treated with burosumab and comparison with other worldwide cohorts.
Mol Genet Genomic Med 2024;
12:e2387. [PMID:
38337160 PMCID:
PMC10858313 DOI:
10.1002/mgg3.2387]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 12/23/2023] [Accepted: 01/17/2024] [Indexed: 02/12/2024] Open
Abstract
BACKGROUND
Disease-related variants in PHEX cause XLH by an increase of fibroblast growth factor 23 (FGF23) circulating levels, resulting in hypophosphatemia and 1,25(OH)2 vitamin D deficiency. XLH manifests in early life with rickets and persists in adulthood with osseous and extraosseous manifestations. Conventional therapy (oral phosphate and calcitriol) improves some symptoms, but evidence show that it is not completely effective, and it can lead to nephrocalcinosis (NC) and hyperparathyroidism (HPT). Burosumab (anti-FGF23 antibody) has shown to be effective and safety in the clinical trials.
METHODS
The current real-world collaborative study evaluated genetic, clinical and laboratory data of XLH Brazilian adult patients treated with burosumab.
RESULTS
Nineteen unrelated patients were studied. Patients reported pain, limb deformities and claudication, before burosumab initiation. 78% of them were previously treated with conventional therapy. The severity of the disease was moderate to severe (15 patients with score >5). At the baseline, 3 patients presented NC (16.7%) and 12 HPT (63%). After 16 ± 8.4 months under burosumab, we observed a significant: increase in stature (p = 0.02), in serum phosphate from 1.90 ± 0.43 to 2.67 ± 0.52 mg/dL (p = 0.02); in TmP/GFR from 1.30 ± 0.46 to 2.27 ± 0.64 mg/dL (p = 0.0001), in 1,25 (OH)2 D from 50.5 ± 23.3 to 71.1 ± 19.1 pg/mL (p = 0.03), and a decrease in iPTH from 86.8 ± 37.4 pg/mL to 66.5 ± 31.1 (p = 0.002). Nineteen variants were found (10 novel). HPT tended to develop in patients with truncated PHEX variants (p = 0.06).
CONCLUSIONS
This study confirms the efficacy and safety of burosumab on XLH adult patients observed in clinical trials. Additionally, we observed a decrease in iPTH levels in patients with moderate to severe HPT at the baseline.
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