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Kiafzezi D, Stamati A, Karagiannis T, Goulis DG, Christoforidis A. Burosumab Efficacy and Safety in Patients with X-Linked Hypophosphatemia: Systematic Review and Meta-analysis of Real-World Data. Calcif Tissue Int 2024:10.1007/s00223-024-01250-z. [PMID: 39008126 DOI: 10.1007/s00223-024-01250-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Accepted: 06/18/2024] [Indexed: 07/16/2024]
Abstract
To assess the efficacy and safety of burosumab in children and adults with X-linked hypophosphatemia based on real-world evidence. MEDLINE (via PubMed) and Cochrane Library were searched until 18 October 2023 for single-arm (before-after) studies. Registries including Clinicaltrials.gov, EU Clinical Trials, WHO International Clinical Trials Registry Platform, and conference abstracts. The outcomes were a change in serum phosphorus concentrations and change in RSS, a change in serum ALP, bone-specific ALP, a change in the ratio of Tubular maximum reabsorption of Phosphate to Glomerular Filtrate rate, a change in serum 1,25(OH)2D and 25(OH)2D concentrations, change in height Z-score, McMaster Universities Osteoarthritis Index (WOMAC) and safety outcomes. An inverse variance random-effects meta-analysis was applied for data synthesis. Fifteen studies (289 participants) were included. Burosumab treatment improved serum phosphate concentrations [mean difference 0.88 mg/dl, 95% confidence interval 0.70 to 1.07, I2 = 92%), Rickets Severity score (mean difference - 1.86, 95% confidence interval - 2.5 to - 1.21, I2 = 71%), serum alkaline phosphate concentrations (mean difference - 1.86, 95% confidence interval - 2.5 to - 1.21, I2 = 71%), serum 1,25(OH)2D concentrations (mean difference 18.91 pg/ml, 95% confidence interval 6.39 to 31.43, I2 = 96%) and renal phosphate reabsorption (mean difference 1.22 mg/dl, 95% confidence interval 0.70 to 1.74, I2 93%). Burosumab treatment improved overall clinical and laboratory findings in patients with X-linked hypophosphatemia.
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Affiliation(s)
- Damiani Kiafzezi
- Postgraduate Program "Research Methodology in Medicine and Health Sciences", Aristotle University of Thessaloniki, Thessaloniki, Greece.
| | - Athina Stamati
- School of Medicine, Faculty of Health Science, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Thomas Karagiannis
- Clinical Research and Evidence-Based Medicine Unit, Second Medical Department, Aristotle University of Thessaloniki, Thessaloniki, Greece
- Diabetes Centre, Second Medical Department, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Dimitrios G Goulis
- Unit of Reproductive Endocrinology, 1st Department of Obstetrics and Gynecology, Medical School, Aristotle University of Thessaloniki, 541 24, Thessaloniki, Greece
| | - Athanasios Christoforidis
- 1st Paediatric Department, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, Ippokratio General Hospital, Thessaloniki, Greece
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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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Affiliation(s)
| | | | - Bárbara Campolina C. Silva
- Hospital Felício Rocho, Osteometabolism Unit of Santa Casa de Belo HorizonteProfessor of Medicine at University Center of Belo Horizonte – UNIBHBelo HorizonteBrazil
| | | | - Érico Higino de Carvalho
- Instituto de Medicina Integrada Professor Fernado Figueira, recifeFederal University of PernambucoRecifeBrazil
| | | | | | - Marcia Ribeiro
- Genetic Unit of Federal University of Rio de JaneiroRio de JaneiroBrazil
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Kassianides X, Bhandari S. Methodology and Baseline Data of a Comparative Exploratory Double-Blinded Randomized Study of Intravenous Iron on Fibroblast Growth Factor 23 and Phosphate in Chronic Kidney Disease. Kidney Blood Press Res 2023; 48:151-164. [PMID: 37015198 DOI: 10.1159/000528313] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Accepted: 11/14/2022] [Indexed: 04/06/2023] Open
Abstract
Modern intravenous iron compounds (e.g., ferric carboxymaltose [FCM] and ferric derisomaltose [FDI]) are utilized in the treatment of iron deficiency anemia in non-dialysis-dependent chronic kidney disease (ND-CKD). Product-specific alterations in the metabolism of fibroblast growth factor 23 (FGF-23) leading to hypophosphatemia have been described for certain intravenous iron compounds, such as FCM, with potential effects on bone and cardiovascular health and quality of life. No prior head-to-head comparison between FCM and FDI exists in ND-CKD. This single-center exploratory double-blind randomized controlled trial primarily aimed to investigate the differential impact of FCM and FDI on FGF-23 and phosphate in patients with iron deficiency +/- anemia and ND-CKD (stages 3a-5 - serum ferritin <200 μg/L or serum ferritin 200-299 μg/L and transferrin saturation <20%). Patients were randomized (1:1) to receive either FCM or FDI over two infusions (1 month apart). Follow-up was 3 months. Measurements of serum intact FGF-23, phosphate, vitamin D metabolites, parathyroid hormone, other bone metabolism, cardiovascular, and quality of life markers were monitored. 168 patients were prescreened. Thirty-five patients were screened; 26 patients were randomized. The mean (standard deviation) age was 67.9 (12.4) years and 17 participants were male. Most participants had stage 4 CKD (median [interquartile range] estimated glomerular filtration rate [eGFR]: 18.0 [11.3] mL/min/1.73 m2). A higher than normal median (interquartile range) level of intact FGF-23 (212.1 [116.4] pg/mL) was noted. Serum phosphate was within normal range, while parathyroid hormone was higher and 1,25 (OH)2 vitamin D lower than the normal range. The "Iron and Phosphaturia - ExplorIRON-CKD" trial will provide important information regarding the differential effect of intravenous iron products in terms of FGF-23, phosphate, and other markers of bone and cardiovascular metabolism, alongside patient-reported outcome measures in patients with ND-CKD.
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Affiliation(s)
- Xenophon Kassianides
- Academic Renal Research Department, Hull University Teaching Hospitals NHS Trust and Hull York Medical School, Kingston upon Hull, UK
| | - Sunil Bhandari
- Academic Renal Research Department, Hull University Teaching Hospitals NHS Trust and Hull York Medical School, Kingston upon Hull, UK
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Arcidiacono T, Foligno NE, Brioni E, Bologna A, Weber G, Mora S, Pitea M, Vitale C, Vezzoli G. Different Efficacy of Burosumab on Physical Performance and Serum Phosphate in Adult Patients with X-Linked Hyphophosphatemic Rickets during the First Six-Month of Treatment. J Clin Med 2023; 12:jcm12082906. [PMID: 37109242 PMCID: PMC10143203 DOI: 10.3390/jcm12082906] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 04/11/2023] [Accepted: 04/14/2023] [Indexed: 04/29/2023] Open
Abstract
Burosumab is a monoclonal anti-FGF23 antibody used to treat patients with X-linked hypophosphatemic rickets (XLH). Its effect on serum phosphate and physical performance was compared in patients during a 6-month treatment with burosumab. Eight adult patients with XHL were treated with burosumab (1 mg/kg s.c. every 28 days). In the first 6 months of treatment, calcium-phosphate metabolism variables were measured, and muscle performance (tested with chair and walking test) and quality of life (tested with fatigue, BPI-pain and BPI-life questionnaires) were estimated. A significant increase in serum phosphate was observed during the treatment. From the 16th week, serum phosphate became significantly lower than its value in the 4th week. No patients had serum phosphate below the normal range at the 10th week, but seven patients were hypophosphatemic in the 20th and 24th week. All patients improved the execution time of the chair test and walking test, which reached a plateau after the 12th week. BPI-pain and BPI-life scores significantly decreased from baseline to the 24th week. In conclusion, a six-month burosumab treatment may significantly improve the general condition and physical performance of adult patients with XLH; this improvement was more stable and more indicative of treatment efficacy than that of serum phosphate.
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Affiliation(s)
- Teresa Arcidiacono
- Nephrology and Dialysis Unit, IRCCS San Raffaele Scientific Institute, 20132 Milan, Italy
- Postgraduate School of Nephrology, Vita Salute San Raffaele University, 20132 Milan, Italy
| | - Nadia E Foligno
- Nephrology and Dialysis Unit, IRCCS San Raffaele Scientific Institute, 20132 Milan, Italy
- Postgraduate School of Nephrology, Vita Salute San Raffaele University, 20132 Milan, Italy
| | - Elena Brioni
- Nephrology and Dialysis Unit, IRCCS San Raffaele Scientific Institute, 20132 Milan, Italy
| | - Arianna Bologna
- Nephrology and Dialysis Unit, IRCCS San Raffaele Scientific Institute, 20132 Milan, Italy
- Postgraduate School of Nephrology, Vita Salute San Raffaele University, 20132 Milan, Italy
| | - Giovanna Weber
- Department of Pediatrics, IRCCS San Raffaele Scientific Institute, Vita Salute San Raffaele University, 20132 Milan, Italy
| | - Stefano Mora
- Laboratory of Pediatric Endocrinology, IRCCS San Raffaele Scientific Institute, 20132 Milan, Italy
| | - Marco Pitea
- Department of Pediatrics, IRCCS San Raffaele Scientific Institute, Vita Salute San Raffaele University, 20132 Milan, Italy
| | - Corrado Vitale
- Nephrology and Dialysis Unit, Mauriziano Hospital, 10128 Turin, Italy
| | - Giuseppe Vezzoli
- Nephrology and Dialysis Unit, IRCCS San Raffaele Scientific Institute, 20132 Milan, Italy
- Postgraduate School of Nephrology, Vita Salute San Raffaele University, 20132 Milan, Italy
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Weber TJ, Imel EA, Carpenter TO, Peacock M, Portale AA, Hetzer J, Merritt JL, Insogna K. Long-term Burosumab Administration Is Safe and Effective in Adults With X-linked Hypophosphatemia. J Clin Endocrinol Metab 2022; 108:155-165. [PMID: 36072994 PMCID: PMC9759172 DOI: 10.1210/clinem/dgac518] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 08/24/2022] [Indexed: 02/03/2023]
Abstract
CONTEXT Burosumab was developed as a treatment option for patients with the rare, lifelong, chronically debilitating, genetic bone disease X-linked hypophosphatemia (XLH). OBJECTIVE Collect additional information on the safety, immunogenicity, and clinical response to long-term administration of burosumab. METHODS UX023-CL203 (NCT02312687) was a Phase 2b, open-label, single-arm, long-term extension study of adult subjects with XLH who participated in KRN23-INT-001 or KRN23-INT-002 studies. The long-term UX023-CL203 study (January 5, 2015 through November 30, 2018) provided data up to 184 weeks. Participants in UX023-CL203 received burosumab based on the last dose in the prior KRN23-INT-001 or KRN23-INT-002 studies (0.3, 0.6, or 1.0 mg/kg given by subcutaneous injection every 4 weeks). At Week 12, burosumab could be titrated upward/downward to achieve fasting serum phosphate levels within the normal range. Primary objectives included long-term safety, the proportion of subjects achieving fasting serum phosphate in the normal range, changes in bone turnover markers, patient-reported outcomes for pain and stiffness, and measures of mobility. RESULTS Fasting serum phosphate levels at the midpoint of the dosing interval (2 weeks postdose, the time of peak effect) were within the normal range in 85% to 100% of subjects. Measures of phosphate metabolism and bone biomarkers generally improved with burosumab therapy, approaching or reaching their respective normal ranges by study end. Improvements in patient-reported outcomes and mobility were sustained throughout the observation period. No new safety findings emerged with longer-term burosumab treatment. CONCLUSION These data support the conclusion that burosumab therapy may be a safe and effective long-term treatment option for adult patients with XLH.
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Affiliation(s)
- Thomas J Weber
- Correspondence: Thomas J. Weber, MD, Division of Endocrinology, Metabolism and Nutrition, 303 Baker House, DUMC 3470, Duke University Medical Center, Durham, NC 27710, USA.
| | - Erik A Imel
- Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | | | - Munro Peacock
- Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | | | - Joel Hetzer
- Ultragenyx Pharmaceutical Inc., Novato, CA 94949, USA
| | | | - Karl Insogna
- Yale University School of Medicine, New Haven, CT 06520, USA
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Complications and Treatments in Adult X-Linked Hypophosphatemia. ENDOCRINES 2022. [DOI: 10.3390/endocrines3030047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
X-linked hypophosphatemia (XLH) is a rare inherited disorder involving elevated levels of fibroblast growth factor (FGF) 23, and is caused by loss-of-function mutations in the PHEX gene. FGF23 induces renal phosphate wasting and suppresses the activation of vitamin D, resulting in defective bone mineralization and rachitic changes in the growth plate and osteomalacia. Conventional treatment with combinations of oral inorganic phosphate and active vitamin D analogs enhances bone calcification, but the efficacy of conventional treatment is insufficient for adult XLH patients to achieve an acceptable quality of life. Burosumab, a fully human monoclonal anti-FGF23 antibody, binds and inhibits FGF23, correcting hypophosphatemia and hypovitaminosis D. This review describes a typical adult with XLH and summarizes the results of clinical trials of burosumab in adults with XLH.
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Trombetti A, Al-Daghri N, Brandi ML, Cannata-Andía JB, Cavalier E, Chandran M, Chaussain C, Cipullo L, Cooper C, Haffner D, Harvengt P, Harvey NC, Javaid MK, Jiwa F, Kanis JA, Laslop A, Laurent MR, Linglart A, Marques A, Mindler GT, Minisola S, Yerro MCP, Rosa MM, Seefried L, Vlaskovska M, Zanchetta MB, Rizzoli R. Interdisciplinary management of FGF23-related phosphate wasting syndromes: a Consensus Statement on the evaluation, diagnosis and care of patients with X-linked hypophosphataemia. Nat Rev Endocrinol 2022; 18:366-384. [PMID: 35484227 DOI: 10.1038/s41574-022-00662-x] [Citation(s) in RCA: 38] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/10/2022] [Indexed: 12/17/2022]
Abstract
X-linked hypophosphataemia (XLH) is the most frequent cause of hypophosphataemia-associated rickets of genetic origin and is associated with high levels of the phosphaturic hormone fibroblast growth factor 23 (FGF23). In addition to rickets and osteomalacia, patients with XLH have a heavy disease burden with enthesopathies, osteoarthritis, pseudofractures and dental complications, all of which contribute to reduced quality of life. This Consensus Statement presents the outcomes of a working group of the European Society for Clinical and Economic Aspects of Osteoporosis, Osteoarthritis and Musculoskeletal Diseases, and provides robust clinical evidence on management in XLH, with an emphasis on patients' experiences and needs. During growth, conventional treatment with phosphate supplements and active vitamin D metabolites (such as calcitriol) improves growth, ameliorates leg deformities and dental manifestations, and reduces pain. The continuation of conventional treatment in symptom-free adults is still debated. A novel therapeutic approach is the monoclonal anti-FGF23 antibody burosumab. Although promising, further studies are required to clarify its long-term efficacy, particularly in adults. Given the diversity of symptoms and complications, an interdisciplinary approach to management is of paramount importance. The focus of treatment should be not only on the physical manifestations and challenges associated with XLH and other FGF23-mediated hypophosphataemia syndromes, but also on the major psychological and social impact of the disease.
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Affiliation(s)
- Andrea Trombetti
- Division of Bone Diseases, Department of Medicine, Geneva University Hospitals and Faculty of Medicine, Geneva, Switzerland
- Division of Geriatrics, Department of Rehabilitation and Geriatrics, Geneva University Hospitals and Faculty of Medicine, Geneva, Switzerland
| | - Nasser Al-Daghri
- Chair for Biomarkers of Chronic Diseases, Biochemistry Department, College of Science, King Saud University, Riyadh, Kingdom of Saudi Arabia
| | | | - Jorge B Cannata-Andía
- Hospital Universitario Central de Asturias (HUCA), Oviedo, Spain
- Universidad de Oviedo, Oviedo, Spain
- Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Oviedo, Spain
- Retic REDinREN-RICORS, 2040-ISCIII, Madrid, Spain
| | - Etienne Cavalier
- Department of Clinical Chemistry, University of Liege, CHU de Liège, Liège, Belgium
| | - Manju Chandran
- Complicated Metabolic Bone Disorders Clinic, Osteoporosis and Bone Metabolism Unit, Department of Endocrinology, Singapore General Hospital, Singapore, Singapore
| | - Catherine Chaussain
- Université de Paris, Institut des maladies musculo-squelettiques, URP2496, UFR Odontologie, Montrouge, France
- AP-HP, FHU DDS-Net, Centre de Référence des Maladies Rares du Métabolisme du Calcium et du Phosphore, Service médecine bucco-dentaire, Hôpital Bretonneau, GH Paris Nord Université de Paris, Paris, France
| | - Lucia Cipullo
- Patient representative with XLH, Geneva, Switzerland
| | - Cyrus Cooper
- MRC Lifecourse Epidemiology Centre, University of Southampton, Southampton, UK
- NIHR Southampton Biomedical Research Centre, University of Southampton and University Hospital Southampton NHS Foundation Trust, Southampton, UK
- NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford, UK
| | - Dieter Haffner
- Department of Paediatric Kidney, Liver and Metabolic Diseases, Hannover Medical School, Hannover, Germany
| | - Pol Harvengt
- XLH Belgium, Belgian association of patients with XLH (a member of the International XLH Alliance), Waterloo, Belgium
| | - Nicholas C Harvey
- MRC Lifecourse Epidemiology Centre, University of Southampton, Southampton, UK
- NIHR Southampton Biomedical Research Centre, University of Southampton and University Hospital Southampton NHS Foundation Trust, Southampton, UK
| | | | - Famida Jiwa
- Chair of the Committee of Patients Societies at the International Osteoporosis Foundation, Osteoporosis Canada, Toronto, Canada
| | - John A Kanis
- Mary McKillop Institute for Health Research, Australian Catholic University, Melbourne, Australia
- Centre for Metabolic Bone Diseases, University of Sheffield Medical School, Sheffield, UK
| | - Andrea Laslop
- Scientific Office, Federal Office for Safety in Health Care, Vienna, Austria
| | - Michaël R Laurent
- Centre for Metabolic Bone Diseases, University Hospitals Leuven, Leuven, Belgium
| | - Agnès Linglart
- Paris-Saclay University, INSERM U1185, Le Kremlin-Bicêtre, France
- AP-HP, endocrinology and diabetes for children, Reference centre for rare diseases of calcium and phosphate metabolism, OSCAR network, Platform of expertise for rare diseases of Paris Saclay Hospital, Bicêtre Paris Saclay Hospital, Le Kremlin-Bicêtre, France
| | - Andréa Marques
- Rheumatology Department, Centro Hospitalar Universitário de Coimbra, Coimbra, Portugal
- Health Sciences Research Unit: Nursing (UICiSA:E), Nursing School of Coimbra, Coimbra, Portugal
| | - Gabriel T Mindler
- Department of Paediatric Orthopaedics, Orthopaedic Hospital Speising, Vienna, Austria
- Vienna Bone and Growth Center, Vienna, Austria
| | - Salvatore Minisola
- Department of Clinical, Internal, Anaesthesiologic and Cardiovascular Sciences, 'Sapienza', Rome University, Rome, Italy
| | | | - Mario Miguel Rosa
- Departamento de Neurociências, Laboratório de Farmacologia Clínica E Terapêutica Faculdade de Medicina da Universidade de Lisboa, Lisbon, Portugal
| | - Lothar Seefried
- Orthopedic Department, University of Würzburg, Würzburg, Germany
| | - Mila Vlaskovska
- Medical Faculty, Department of Pharmacology, Medical University Sofia, Sofia, Bulgaria
| | - María Belén Zanchetta
- Instituto de Investigaciones Metabólicas (IDIM), Universidad del Salvador, Buenos Aires, Argentina
| | - René Rizzoli
- Division of Bone Diseases, Department of Medicine, Geneva University Hospitals and Faculty of Medicine, Geneva, Switzerland.
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Namba N, Kubota T, Muroya K, Tanaka H, Kanematsu M, Kojima M, Orihara S, Kanda H, Seino Y, Ozono K. Safety and Efficacy of Burosumab in Pediatric Patients With X-linked Hypophosphatemia: A Phase 3/4 Open-Label Trial. J Endocr Soc 2022; 6:bvac021. [PMID: 35356008 PMCID: PMC8962727 DOI: 10.1210/jendso/bvac021] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Indexed: 11/19/2022] Open
Abstract
Objective Burosumab, an anti-fibroblast growth factor 23 antibody, was recently approved for the treatment of X-linked hypophosphatemia (XLH). We evaluated the safety and efficacy of burosumab in pediatric XLH patients. Methods This open-label, phase 3/4 trial of ≤ 124 weeks’ duration was conducted at 4 Japanese medical centers. Fifteen children aged 1 to 12 years with XLH were included. All had previously been treated with phosphorus or vitamin D. Subcutaneous burosumab was administered every 2 weeks, starting with 0.8 mg/kg, and adjusted based on serum phosphorus levels and any safety concerns (maximum 2 mg/kg). Safety assessments included the frequency of treatment-emergent adverse events (TEAEs). Efficacy of burosumab on biochemical markers, clinical markers of rickets, motor function, and growth was also evaluated. Results The average treatment duration was 121.7 weeks. Frequently reported TEAEs were nasopharyngitis (46.7%), dental caries (40.0%), and influenza (33.3%). At baseline, patients had low serum phosphorus concentrations (2.6 ± 0.3 mg/dL) and low-to-normal 1,25-dihydroxyvitamin D concentrations (24.7 ± 12.7 pg/mL), which increased with burosumab treatment and were maintained during the study period. Alkaline phosphatase decreased continuously. At baseline, the mean ± SD total Thacher Rickets Severity Score (RSS) was 1.3 ± 1.2, and 4 patients (26.7%) had an RSS ≥ 2.0. Mean Radiographic Global Impression of Change and RSS tended to improve, particularly in patients with higher baseline RSS. There was a trend toward increased 6-minute walk test distance. No apparent changes in growth rate were observed. Conclusion Burosumab has a good safety profile and is effective in pediatric patients with XLH.
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Affiliation(s)
- Noriyuki Namba
- Division of Pediatrics and Perinatology, Tottori University Faculty of Medicine, Tottori, Japan
| | - Takuo Kubota
- Department of Pediatrics, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Koji Muroya
- Department of Endocrinology and Metabolism, Kanagawa Children's Medical Center, Kanagawa, Japan
| | - Hiroyuki Tanaka
- Department of Pediatrics, Okayama Saiseikai Outpatient Center Hospital, Okayama, Japan
| | | | | | | | | | - Yoshiki Seino
- Department of Pediatrics, Osaka Hospital, Japan Community Healthcare Organization (JCHO), Osaka, Japan
| | - Keiichi Ozono
- Department of Pediatrics, Osaka University Graduate School of Medicine, Osaka, Japan
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9
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Lafage-Proust MH. What are the benefits of the anti-FGF23 antibody burosumab on the manifestations of X-linked hypophosphatemia in adults in comparison with conventional therapy? A review. THERAPEUTIC ADVANCES IN RARE DISEASE 2022; 3:26330040221074702. [PMID: 37180412 PMCID: PMC10032432 DOI: 10.1177/26330040221074702] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Accepted: 01/03/2022] [Indexed: 05/16/2023]
Abstract
X-linked hypophosphatemia (XLH) is a genetic disease mostly related to PHEX gene mutations which increases FGF23 serum levels, leading to hypophosphatemia and osteomalacia in adults, while affected children, in addition, develop rickets. Most of adults with XLH suffer from reduced quality of life and physical disability due to chronic bone and joint pain related to limb deformities, early osteoarthritis, delayed-healing of insufficiency fractures, and enthesopathies. Dental infections, muscle dysfunction, and deafness are also frequent. The current treatment consists of 2-5 times daily oral administration of phosphate combined to active vitamin D, often badly tolerated with immediate digestive side effects, responsible for poor compliance. In the long term, it may induce nephrocalcinosis and hyperparathyroidism. Burosumab, an anti-FGF23 blocking antibody, was approved for treating children with XLH in many countries. A randomized 24-week-long placebo-controlled trial, followed by an open-label period of equal duration was conducted in 134 XLH adults treated with 1 mg/kg burosumab/4 weeks. During burosumab treatment, 94% of the patients normalized serum phosphate values versus 7% in the placebo group. Fracture healing was increased 16.7 times compared with placebo-treated patients. All pain and disability tests improved significantly in a time-dependent manner. Burosumab for 48 weeks improved histological lesions of osteomalacia in a single-arm longitudinal study analyzing paired bone biopsies. Another single-arm, open-label study investigated the long-term safety and efficacy of burosumab in 20 adult patients followed for 3.2 years. Burosumab was beneficial on pain and disability scores and on bone remodeling markers. No major side effects especially no hyperphosphatemic episodes were reported. Overall, the benefit/risk ratio of burosumab is positive in adult patients with clinical and/or biological complications of XLH. Burosumab corrects hypophosphatemia, promotes fracture healing, and induces a modest but significant effect on XLH-induced subjective pain and disability symptoms. Plain language title and summary Effects of conventional treatment and burosumab in adults with X-linked hypophosphatemia.X-linked hypophosphatemia (XLH) is a disease of genetic origin that affects mineralized tissues (skeleton and teeth) and impairs muscle function. It induces a decrease in blood phosphate levels. This leads to under mineralization of bones and insufficiency fractures that heal slowly, associated with poor dental health characterized by spontaneous dental abscesses. Adults with XLH suffer from chronic pain and limb deformities that alter their quality of life. They are currently treated with daily administration of vitamin D and several daily doses of phosphate. This treatment may induce parathyroid gland dysfunction and mineral deposits in the kidney. If not tightly monitored, these side effects may lead to tertiary hyperparathyroidism and the need for parathyroid gland surgery, or to nephrocalcinosis which may proceed to chronic kidney disease. Burosumab is an antibody that blocks the action of FGF23 the factor that circulates in excess in blood and is responsible for phosphate renal leak in XLH. Three studies demonstrated that burosumab, injected every 4 weeks, is efficient and safe for treating adults with XLH.
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Salcion A, Herrou J, Briot K. Adult rheumatologic features, treatment and complications of X-linked hypophosphatemia. Arch Pediatr 2021; 28:606-611. [PMID: 34625379 DOI: 10.1016/j.arcped.2021.09.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
X-linked hypophosphatemia (XLH) is a rare genetic phosphate disorder caused mainly by PHEX mutations. Unlike for children, knowledge of the disease's manifestations in adults is limited. Musculoskeletal symptoms are the main feature of the disease in young adults associated with a heavy burden on patients' life. They include fractures and pseudofractures, pain, joint stiffness, osteoarthritis, enthesopathies, and muscle weakness, eventually leading to impaired quality of life. Conventional treatment with phosphate supplements and vitamin D analogs is indicated in symptomatic patients. Appropriate rehabilitation is also a key to the management of the disease to improve physical function and decrease pain, stiffness, and fatigue. Regarding the incidence and consequences of musculoskeletal features in XLH, all patients should be assessed by a bone disease specialist and, if necessary, managed by a multidisciplinary team.
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Affiliation(s)
- Axelle Salcion
- Department of Rheumatology, Reference Center for Rare Disorders for Calcium and Phosphate Metabolism, Cochin Hospital, Paris, France
| | - Julia Herrou
- Department of Rheumatology, Reference Center for Rare Disorders for Calcium and Phosphate Metabolism, Cochin Hospital, Paris, France; INSERM U1153, Paris, France
| | - Karine Briot
- Department of Rheumatology, Reference Center for Rare Disorders for Calcium and Phosphate Metabolism, Cochin Hospital, Paris, France; INSERM U1153, Paris, France.
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11
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Vincze J, Skinner BW, Tucker KA, Conaway KA, Lowery JW, Hum JM. The Metabolic Bone Disease X-linked Hypophosphatemia: Case Presentation, Pathophysiology and Pharmacology. Life (Basel) 2021; 11:life11060563. [PMID: 34203792 PMCID: PMC8232744 DOI: 10.3390/life11060563] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 06/09/2021] [Accepted: 06/12/2021] [Indexed: 11/16/2022] Open
Abstract
The authors present a stereotypical case presentation of X-linked hypophosphatemia (XLH) and provide a review of the pathophysiology and related pharmacology of this condition, primarily focusing on the FDA-approved medication burosumab. XLH is a renal phosphate wasting disorder caused by loss of function mutations in the PHEX gene (phosphate-regulating gene with homologies to endopeptidases on the X chromosome). Typical biochemical findings include elevated serum levels of bioactive/intact fibroblast growth factor 23 (FGF23) which lead to (i) low serum phosphate levels, (ii) increased fractional excretion of phosphate, and (iii) inappropriately low or normal 1,25-dihydroxyvitamin D (1,25-vitD). XLH is the most common form of heritable rickets and short stature in patients with XLH is due to chronic hypophosphatemia. Additionally, patients with XLH experience joint pain and osteoarthritis from skeletal deformities, fractures, enthesopathy, spinal stenosis, and hearing loss. Historically, treatment for XLH was limited to oral phosphate supplementation, active vitamin D supplementation, and surgical intervention for cases of severe bowed legs. In 2018, the United States Food and Drug Administration (FDA) approved burosumab for the treatment of XLH and this medication has demonstrated substantial benefit compared with conventional therapy. Burosumab binds circulating intact FGF23 and blocks its biological effects in target tissues, resulting in increased serum inorganic phosphate (Pi) concentrations and increased conversion of inactive vitamin D to active 1,25-vitD.
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Affiliation(s)
- Jon Vincze
- College of Osteopathic Medicine Division of Biomedical Science, Marian University, 3200 Cold Spring Rd., Indianapolis, IN 46222, USA; (J.V.); (K.A.C.)
- Bone & Muscle Research Group, Marian University, 3200 Cold Spring Rd., Indianapolis, IN 46222, USA
| | - Brian W. Skinner
- College of Osteopathic Medicine Division of Clinical Sciences Marian University, 3200 Cold Spring Rd., Indianapolis, IN 46222, USA;
| | - Katherine A. Tucker
- Leighton School of Nursing, Marian University, 3200 Cold Spring Rd., Indianapolis, IN 46222, USA;
| | - Kory A. Conaway
- College of Osteopathic Medicine Division of Biomedical Science, Marian University, 3200 Cold Spring Rd., Indianapolis, IN 46222, USA; (J.V.); (K.A.C.)
- Bone & Muscle Research Group, Marian University, 3200 Cold Spring Rd., Indianapolis, IN 46222, USA
| | - Jonathan W. Lowery
- College of Osteopathic Medicine Division of Biomedical Science, Marian University, 3200 Cold Spring Rd., Indianapolis, IN 46222, USA; (J.V.); (K.A.C.)
- Bone & Muscle Research Group, Marian University, 3200 Cold Spring Rd., Indianapolis, IN 46222, USA
- Correspondence: (J.W.L.); (J.M.H.); Tel./Fax: +1-317-955-6621 (J.W.L.); +1-317-955-6265 (J.M.H.)
| | - Julia M. Hum
- College of Osteopathic Medicine Division of Biomedical Science, Marian University, 3200 Cold Spring Rd., Indianapolis, IN 46222, USA; (J.V.); (K.A.C.)
- Bone & Muscle Research Group, Marian University, 3200 Cold Spring Rd., Indianapolis, IN 46222, USA
- Correspondence: (J.W.L.); (J.M.H.); Tel./Fax: +1-317-955-6621 (J.W.L.); +1-317-955-6265 (J.M.H.)
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Ishigami J, Grams ME, Michos ED, Lutsey PL, Matsushita K. 25-hydroxyvitamin D, Fibroblast Growth Factor 23, and Risk of Acute Kidney Injury Over 20 Years of Follow-Up. Kidney Int Rep 2021; 6:1299-1308. [PMID: 34013108 PMCID: PMC8116771 DOI: 10.1016/j.ekir.2021.02.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 01/11/2021] [Accepted: 02/01/2021] [Indexed: 11/25/2022] Open
Abstract
INTRODUCTION Low serum 25-hydroxyvitamin D levels have been identified as a risk factor for acute kidney injury (AKI) among critically ill patients. Whether low 25-hydroxyvitamin D levels are associated with long-term incidence of hospitalization with AKI in the general population is unknown. METHODS Among 12,380 participants (mean age, 57 years; 24% black) in the Atherosclerosis Risk in Communities (ARIC) Study who attended visit 2 (1990-1992), we explored the association of serum 25-hydroxyvitamin D with incident hospitalization with AKI. Multivariable Cox models were used to estimate hazard ratios (HRs). We also examined the association of serum fibroblast growth factor 23 (FGF23) with AKI. RESULTS During a median follow-up of 24.3 years, 2145 participants had incident hospitalization with AKI (crude incidence rate: 8.3; 95% confidence interval [CI]: 8.0-8.7, per 1,000 person-years). In multivariable Cox models (including adjustment for kidney function), lower 25-hydroxyvitamin D and higher FGF23 levels were each significantly associated with an increased risk of AKI (HR: 1.35; 95% CI: 1.17-1.54, for lowest vs. highest quartile for 25-hydroxyvitamin D, and HR: 1.19; 95% CI: 1.05-1.36, for highest vs. lowest quartile for FGF23). The association was consistent across demographic and clinical subgroups, regardless of whether AKI was the primary diagnosis for hospitalization, and when adjusting for incident chronic kidney disease (CKD) or cardiovascular disease (CVD) as a time-varying covariate. CONCLUSION Among middle- to older-age adults in the community, low 25-hydroxyvitamin D and high FGF23 levels were independently associated with an increased risk of AKI. Future studies should explore underlying mechanisms linking these bone mineral metabolism markers with kidney injury.
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Affiliation(s)
- Junichi Ishigami
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Morgan E. Grams
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
- Department of Medicine, Johns Hopkins University, Baltimore, Maryland, USA
| | - Erin D. Michos
- Department of Medicine, Johns Hopkins University, Baltimore, Maryland, USA
| | - Pamela L. Lutsey
- Division of Epidemiology and Community Health, University of Minnesota, Minneapolis, Minnesota, USA
| | - Kunihiro Matsushita
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
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13
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Cheung M, Rylands AJ, Williams A, Bailey K, Bubbear J. Patient-Reported Complications, Symptoms, and Experiences of Living With X-Linked Hypophosphatemia Across the Life-Course. J Endocr Soc 2021; 5:bvab070. [PMID: 34258488 PMCID: PMC8272533 DOI: 10.1210/jendso/bvab070] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Indexed: 11/19/2022] Open
Abstract
Context X-linked hypophosphatemia (XLH) is a rare, genetic phosphate-wasting disease resulting in bone, muscular, and dental problems, beginning in childhood and increasing in adulthood. Objective This qualitative analysis aimed to explore patient-reported symptoms, complications, and experiences of XLH over the life-course, using data from a large multinational online survey. Methods Responses to 2 open-ended questions from 209 adults and 86 children/adolescents (proxy report) with self-reported XLH were analyzed in 8 age groups. Two researchers independently coded and analyzed the responses, using thematic analysis, with differences settled among a multidisciplinary group. Six themes were identified, with age subgroup analysis conducted on the 3 most common, according to coding frequency. Results Within theme 1, “Clinical Signs and Symptoms of XLH,” “Pain” was a dominant subtheme across the life-course, but “Skeletal Pathology” dominated the responses of children/adolescents. Within theme 2, “Impacts of Clinical Signs and Symptoms,” interference with “Physical Exertion” and “Emotional Wellbeing” (comprising depression/anxiety in adults and lack of self-esteem in children/adolescents) was reported across all ages. For theme 3, “Negative Treatment Experiences,” “Medication” was problematic for children, with adults reporting lack of “Access to Appropriate Treatment.” Three further themes were identified: “Resilience,” “Positive Treatment Experiences,” and “Information Needs.” Conclusion The multiple burdens imposed on people with XLH throughout their lifetime encompassed the physical, emotional, and social, although the most challenging symptoms or complications differed between ages. Burden was further exacerbated by adults’ lack of access to appropriate treatment, illustrating the need for age-appropriate multidisciplinary care.
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Affiliation(s)
- Moira Cheung
- Evelina London Children's Hospital, London, SE1 7EH, UK
| | - Angela J Rylands
- Kyowa Kirin International, Galashiels, Selkirkshire, TD1 1QH, UK
| | - Angela Williams
- Kyowa Kirin International, Galashiels, Selkirkshire, TD1 1QH, UK
| | | | - Judith Bubbear
- Royal National Orthopaedic Hospital NHS Trust, Middlesex, HA7 4LP, UK
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14
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Marcucci G, Brandi ML. Congenital Conditions of Hypophosphatemia Expressed in Adults. Calcif Tissue Int 2021; 108:91-103. [PMID: 32409880 DOI: 10.1007/s00223-020-00695-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Accepted: 04/15/2020] [Indexed: 01/05/2023]
Abstract
The main congenital conditions of hypophosphatemia expressed in adulthood include several forms of hereditary hypophosphatemic rickets and a congenital disorder of vitamin D metabolism characterized by osteomalacia and hypophosphatemia in adult patients. Hypophosphatemia in adults is defined as serum phosphate concentration < 0.80 mmol/L. The principal regulators of phosphate homeostasis, as is well known, are parathyroid hormone (PTH), activated vitamin D, and Fibroblast Growth Factor 23 (FGF23). Differential diagnosis of hypophosphatemia is based on the evaluation of mechanisms leading to this alteration, such as high PTH activity, inadequate phosphate absorption from the gut, or renal phosphate wasting, either due to primary tubular defects or high FGF23 levels. The most common inherited form associated to hypophosphatemia is X-linked hypophosphatemic rickets (XLH), caused by PHEX gene mutations with enhanced secretion of the FGF23. Until now, the management of hypophosphatemia in adulthood has been poorly investigated. It is widely debated whether adult patients benefit from the conventional treatments normally used for pediatric patients. The new treatment for XLH with burosumab, a recombinant human IgG1 monoclonal antibody that binds to FGF23, blocking its activity, may change the pharmacological management of adult subjects with hypophosphatemia associated to FGF23-dependent mechanisms.
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Affiliation(s)
- Gemma Marcucci
- Bone Metabolic Diseases Unit, Department of Biomedical, Experimental and Clinical Sciences, University of Florence, AOU Careggi, Florence, Italy
| | - Maria Luisa Brandi
- Bone Metabolic Diseases Unit, Department of Biomedical, Experimental and Clinical Sciences, University of Florence, AOU Careggi, Florence, Italy.
- Head Bone Metabolic Diseases Unit, Department of Biomedical, Experimental and Clinical Sciences, University of Florence, Largo Palagi 1, 50139, Florence, Italy.
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15
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Seefried L, Smyth M, Keen R, Harvengt P. Burden of disease associated with X-linked hypophosphataemia in adults: a systematic literature review. Osteoporos Int 2021; 32:7-22. [PMID: 32710160 PMCID: PMC7755619 DOI: 10.1007/s00198-020-05548-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Accepted: 07/08/2020] [Indexed: 12/30/2022]
Abstract
UNLABELLED This systematic review collated evidence on the burden of XLH in adults. Data captured highlight the substantial ongoing burden of XLH in adulthood and identified unmet needs. Greater awareness and understanding of the impact of XLH in adulthood are needed to improve care and outcomes in adults with XLH. INTRODUCTION X-linked hypophosphataemia (XLH) is a rare metabolic bone disease characterized by renal phosphate wasting and musculoskeletal manifestations. Whilst the disease's impact in children is well documented, information on the effects of this progressive, debilitating condition on adults is lacking. This systematic review aimed to collate existing evidence on the burden of XLH in adulthood to identify unmet needs. METHODS MEDLINE, Embase and Cochrane Library databases and recent congress reports were searched on 19 February 2019 for English-language publications describing the medical, humanistic and socio-economic impact of XLH in adults (≥ 18 years old). In addition, a structured Internet search was conducted. RESULTS Of the 2351 articles identified, 91 met the selection criteria along with 44 congress abstracts. Data show that adults with XLH experience a range of clinical manifestations, particularly skeletal deformities and (pseudo)fractures, along with pain, dental abnormalities and impaired physical function and mobility. XLH in adulthood impacts on quality of life and places limitations on daily activities. The level of healthcare resource utilization among adults with XLH is indicative of substantial socio-economic burden; further research is needed to quantitate the economic impact on the healthcare system, society and patients. Adults with XLH may not receive appropriate care and treatment; a possible explanation for this is a lack of awareness among healthcare professionals. CONCLUSION XLH in adults is associated with considerable disease burden and unmet needs. Forthcoming studies and increased awareness of the impact of XLH in adulthood should help to improve management of XLH in adulthood and patient outcomes.
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Affiliation(s)
- L Seefried
- Orthopedic Institute, König-Ludwig Haus, University of Würzburg, Würzburg, Germany
| | - M Smyth
- Kyowa Kirin International, Galashiels, UK
| | - R Keen
- Royal National Orthopaedic Hospital, Stanmore, UK
| | - P Harvengt
- RVRH-XLH, French association of patients with XLH (a member of the International XLH Alliance), 20 rue Merlin de Thionville, Appt 120, 92150, Suresnes, France.
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16
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Athonvarangkul D, Insogna KL. New Therapies for Hypophosphatemia-Related to FGF23 Excess. Calcif Tissue Int 2021; 108:143-157. [PMID: 32504139 DOI: 10.1007/s00223-020-00705-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Accepted: 05/12/2020] [Indexed: 12/12/2022]
Abstract
FGF23 is a hormone produced by osteocytes in response to an elevation in the concentration of extracellular phosphate. Excess production of FGF23 by bone cells, or rarely by tumors, is the hormonal basis for several musculoskeletal syndromes characterized by hypophosphatemia due to renal phosphate wasting. FGF23-dependent chronic hypophosphatemia causes rickets and osteomalacia, as well as other skeletal complications. Genetic disorders of FGF23-mediated hypophosphatemia include X-linked hypophosphatemia (XLH), autosomal dominant hypophosphatemic rickets (ADHR), autosomal recessive hypophosphatemic rickets (ARHR), fibrous dysplasia of bone, McCune-Albright syndrome, and epidermal nevus syndrome (ENS), also known as cutaneous skeletal hypophosphatemia syndrome (CSHS). The principle acquired form of FGF23-mediated hypophosphatemia is tumor-induced osteomalacia (TIO). This review summarizes current knowledge about the pathophysiology and clinical presentation of the most common FGF23-mediated conditions, with a focus on new treatment modalities. For many decades, calcitriol and phosphate supplements were the mainstay of therapy. Recently, burosumab, a monoclonal blocking antibody to FGF23, has been approved for treatment of XLH in children and adults, and an active comparator trial in children has shown good efficacy and safety for this drug. The remainder of FGF23-mediated hypophosphatemic disorders continue to be treated with phosphate and calcitriol, although ongoing trials with burosumab for treatment of tumor-induced osteomalacia show early promise. Burosumab may be an effective treatment for the remainder of FGF23-mediated disorders, but clinical trials to support that possibility are at present not available.
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Affiliation(s)
- Diana Athonvarangkul
- Department of Medicine Section of Endocrinology, Yale School of Medicine, PO Box 802080, New Haven, CT, 06520, USA.
| | - Karl L Insogna
- Department of Medicine Section of Endocrinology, Yale School of Medicine, PO Box 802080, New Haven, CT, 06520, USA
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Ishigami J, Taliercio JT, Feldman HI, Srivastava A, Townsend RR, Cohen DL, Horwitz EJ, Rao P, Charleston J, Fink JC, Ricardo AC, Sondheimer J, Chen TK, Wolf M, Isakova T, Appel LJ, Matsushita K. Fibroblast Growth Factor 23 and Risk of Hospitalization with Infection in Chronic Kidney Disease: The Chronic Renal Insufficiency Cohort (CRIC) Study. J Am Soc Nephrol 2020; 31:1836-1846. [PMID: 32576601 DOI: 10.1681/asn.2019101106] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Accepted: 04/14/2020] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND Risk of infectious disease is increased among individuals with CKD. Fibroblast growth factor 23 (FGF23) is often elevated in CKD, and may impair immune function directly or indirectly through proinflammatory and vitamin D-suppressing pathways. Whether FGF23 is associated with risk of infection has not been evaluated in a CKD population. METHODS In 3655 participants of the Chronic Renal Insufficiency Cohort study, we evaluated the association of baseline plasma levels of C-terminal FGF23 with time to first hospitalization with major infection, defined by hospital discharge with a diagnosis code for urinary tract infection, pneumonia, cellulitis/osteomyelitis, or bacteremia/septicemia. Multivariable Cox models were used to estimate hazard ratios (HRs) and adjust for confounding. RESULTS During a median follow-up of 6.5 years, 1051 individuals (29%) were hospitalized with major infection. Multivariable Cox analysis indicated a graded increase in the risk of infection with higher levels of FGF23 (HR, 1.51; 95% CI, 1.23 to 1.85 with the highest quartile [≥235.9 RU/ml] versus lowest quartile [<95.3 RU/ml]; HR, 1.26; 95% CI, 1.18 to 1.35 per SD increment in log FGF23). The association was consistent across infection subtypes and demographic and clinical subgroups, and remained significant after additional adjustment for biomarkers of inflammation (IL-6, TNF-α, high-sensitivity C-reactive protein, fibrinogen, and albumin), and bone mineral metabolism (25-hydroxyvitamin D, phosphorus, calcium, and parathyroid hormone). The association was consistent across infection subtypes of urinary tract infection (482 cases), cellulitis/osteomyelitis (422 cases), pneumonia (399 cases), and bacteremia/septicemia (280 cases). CONCLUSIONS Among individuals with CKD, higher FGF23 levels were independently and monotonically associated with an increased risk of hospitalization with infection.
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Affiliation(s)
- Junichi Ishigami
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland .,Welch Center for Prevention, Epidemiology, and Clinical Research, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - Jonathan T Taliercio
- Department of Nephrology and Hypertension, Cleveland Clinic Foundation, Cleveland, Ohio
| | - Harold I Feldman
- Department of Biostatistics and Epidemiology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Anand Srivastava
- Division of Nephrology and Hypertension, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Raymond R Townsend
- Department of Biostatistics and Epidemiology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Debbie L Cohen
- Department of Biostatistics and Epidemiology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Edward J Horwitz
- Division of Nephrology, MetroHealth Medical Center, Cleveland, Ohio
| | - Panduranga Rao
- Division of Nephrology, University of Michigan, Ann Arbor, Michigan
| | - Jeanne Charleston
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - Jeffrey C Fink
- Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland
| | - Ana C Ricardo
- Division of Nephrology, University of Illinois, Chicago, Illinois
| | - James Sondheimer
- Division of Nephrology and Hypertension, Wayne State University School of Medicine, Detroit, Michigan
| | - Teresa K Chen
- Division of Nephrology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Myles Wolf
- Division of Nephrology, Department of Medicine, and Duke Clinical Research Institute, Duke University School of Medicine, Durham, North Carolina
| | - Tamara Isakova
- Division of Nephrology and Hypertension, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Lawrence J Appel
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland.,Welch Center for Prevention, Epidemiology, and Clinical Research, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - Kunihiro Matsushita
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland.,Welch Center for Prevention, Epidemiology, and Clinical Research, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
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Torregrosa JV, Sánchez Del Pozo J, Luiz Yanes MI, Muñoz Torres M. Panel Discussion: Some Aspects of the Management of Patients with X-Linked Hypophosphataemic Rickets. Adv Ther 2020; 37:121-126. [PMID: 32236878 DOI: 10.1007/s12325-019-01208-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Indexed: 12/01/2022]
Abstract
X-linked hypophosphataemia (XLH) rickets is a rare disease frequently misdiagnosed and mismanaged. Despite having clinical guidelines that offers some therapeutic recommendations based on the clinical experience of experts, physicians still have questions about some important aspects of the diagnosis and treatment of XLH, such as when the disease should be suspected, who should be in charge of the diagnosis, what should be done once the disease is diagnosed, or what therapeutic options are currently available. The objective of this paper is to answer some of the more frequent questions related to the management of patients with XLH by a group of experts participating in a scientific conference on XLH held in Madrid.
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Affiliation(s)
- José-Vicente Torregrosa
- Servicio de Nefrología y Trasplante Renal, Hospital Clinic, Universidad de Barcelona, Barcelona, Spain.
| | - Jaime Sánchez Del Pozo
- Sección de Endocrinología, Nutrición y Dismorfología Pediátrica, Servicio de Pediatría, Hospital Universitario 12 de Octubre, Madrid, Spain
| | - María Isabel Luiz Yanes
- Unidad de Nefrología Pediátrica, Servicio de Pediatría, Hospital Universitario Nuestra Señora de Candelaria, Santa Cruz de Tenerife, Spain
| | - Manuel Muñoz Torres
- Departamento de Medicina, Universidad de Granada, UGC Endocrinología y Nutrición. Hospital Universitario San Cecilio, CIBERFES, Instituto de Salud Carlos III, Instituto de Investigación Biosanitaria de Granada, Granada, Spain
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Chande S, Caballero D, Ho BB, Fetene J, Serna J, Pesta D, Nasiri A, Jurczak M, Chavkin NW, Hernando N, Giachelli CM, Wagner CA, Zeiss C, Shulman GI, Bergwitz C. Slc20a1/Pit1 and Slc20a2/Pit2 are essential for normal skeletal myofiber function and survival. Sci Rep 2020; 10:3069. [PMID: 32080237 PMCID: PMC7033257 DOI: 10.1038/s41598-020-59430-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Accepted: 01/29/2020] [Indexed: 01/25/2023] Open
Abstract
Low blood phosphate (Pi) reduces muscle function in hypophosphatemic disorders. Which Pi transporters are required and whether hormonal changes due to hypophosphatemia contribute to muscle function is unknown. To address these questions we generated a series of conditional knockout mice lacking one or both house-keeping Pi transporters Pit1 and Pit2 in skeletal muscle (sm), using the postnatally expressed human skeletal actin-cre. Simultaneous conditional deletion of both transporters caused skeletal muscle atrophy, resulting in death by postnatal day P13. smPit1-/-, smPit2-/- and three allele mutants are fertile and have normal body weights, suggesting a high degree of redundance for the two transporters in skeletal muscle. However, these mice show a gene-dose dependent reduction in running activity also seen in another hypophosphatemic model (Hyp mice). In contrast to Hyp mice, grip strength is preserved. Further evaluation of the mechanism shows reduced ERK1/2 activation and stimulation of AMP kinase in skeletal muscle from smPit1-/-; smPit2-/- mice consistent with energy-stress. Similarly, C2C12 myoblasts show a reduced oxygen consumption rate mediated by Pi transport-dependent and ERK1/2-dependent metabolic Pi sensing pathways. In conclusion, we here show that Pit1 and Pit2 are essential for normal myofiber function and survival, insights which may improve management of hypophosphatemic myopathy.
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Affiliation(s)
- Sampada Chande
- Department of Internal Medicine, Section Endocrinology, Yale University School of Medicine, New Haven, CT, USA
| | - Daniel Caballero
- Department of Internal Medicine, Section Endocrinology, Yale University School of Medicine, New Haven, CT, USA
| | - Bryan B Ho
- Department of Internal Medicine, Section Endocrinology, Yale University School of Medicine, New Haven, CT, USA
| | - Jonathan Fetene
- Department of Internal Medicine, Section Endocrinology, Yale University School of Medicine, New Haven, CT, USA
| | - Juan Serna
- Department of Internal Medicine, Section Endocrinology, Yale University School of Medicine, New Haven, CT, USA
| | - Dominik Pesta
- Department of Cellular&Molecular Physiology, Yale University School of Medicine, New Haven, CT, USA
- German Diabetes Center, Düsseldorf, Germany, University of Washington, Box 355061, Foege Hall Seattle, WA, 98195, USA
| | - Ali Nasiri
- Department of Cellular&Molecular Physiology, Yale University School of Medicine, New Haven, CT, USA
| | - Michael Jurczak
- Department of Internal Medicine, Section Endocrinology, Yale University School of Medicine, New Haven, CT, USA
- Department of Medicine, Division of Endocrinology, University of Pittsburgh, University of Washington, Box 355061, Foege Hall Seattle, WA, 98195, USA
| | - Nicholas W Chavkin
- Department of Bioengineering, University of Washington, Box 355061, Foege Hall Seattle, WA, 98195, USA
| | - Nati Hernando
- Institute of Physiology, University of Zürich, Switzerland and National Center of Competence in Research NCCR Kidney.CH, Zürich, Switzerland
| | - Cecilia M Giachelli
- Department of Bioengineering, University of Washington, Box 355061, Foege Hall Seattle, WA, 98195, USA
| | - Carsten A Wagner
- Institute of Physiology, University of Zürich, Switzerland and National Center of Competence in Research NCCR Kidney.CH, Zürich, Switzerland
| | - Caroline Zeiss
- Comparative Medicine, Yale University School of Medicine, New Haven, CT, USA
| | - Gerald I Shulman
- Department of Internal Medicine, Section Endocrinology, Yale University School of Medicine, New Haven, CT, USA
- Department of Cellular&Molecular Physiology, Yale University School of Medicine, New Haven, CT, USA
| | - Clemens Bergwitz
- Department of Internal Medicine, Section Endocrinology, Yale University School of Medicine, New Haven, CT, USA.
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20
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Haffner D, Emma F, Eastwood DM, Duplan MB, Bacchetta J, Schnabel D, Wicart P, Bockenhauer D, Santos F, Levtchenko E, Harvengt P, Kirchhoff M, Di Rocco F, Chaussain C, Brandi ML, Savendahl L, Briot K, Kamenicky P, Rejnmark L, Linglart A. Clinical practice recommendations for the diagnosis and management of X-linked hypophosphataemia. Nat Rev Nephrol 2020; 15:435-455. [PMID: 31068690 PMCID: PMC7136170 DOI: 10.1038/s41581-019-0152-5] [Citation(s) in RCA: 265] [Impact Index Per Article: 66.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
X-linked hypophosphataemia (XLH) is the most common cause of inherited phosphate wasting and is associated with severe complications such as rickets, lower limb deformities, pain, poor mineralization of the teeth and disproportionate short stature in children as well as hyperparathyroidism, osteomalacia, enthesopathies, osteoarthritis and pseudofractures in adults. The characteristics and severity of XLH vary between patients. Because of its rarity, the diagnosis and specific treatment of XLH are frequently delayed, which has a detrimental effect on patient outcomes. In this Evidence-Based Guideline, we recommend that the diagnosis of XLH is based on signs of rickets and/or osteomalacia in association with hypophosphataemia and renal phosphate wasting in the absence of vitamin D or calcium deficiency. Whenever possible, the diagnosis should be confirmed by molecular genetic analysis or measurement of levels of fibroblast growth factor 23 (FGF23) before treatment. Owing to the multisystemic nature of the disease, patients should be seen regularly by multidisciplinary teams organized by a metabolic bone disease expert. In this article, we summarize the current evidence and provide recommendations on features of the disease, including new treatment modalities, to improve knowledge and provide guidance for diagnosis and multidisciplinary care. In this Evidence-Based Guideline on X-linked hypophosphataemia, the authors identify the criteria for diagnosis of this disease, provide guidance for medical and surgical treatment and explain the challenges of follow-up.
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Affiliation(s)
- Dieter Haffner
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Hannover Medical School, Hannover, Germany. .,Center for Congenital Kidney Diseases, Center for Rare Diseases, Hannover Medical School, Hannover, Germany.
| | - Francesco Emma
- Department of Pediatric Subspecialties, Division of Nephrology, Children's Hospital Bambino Gesù - IRCCS, Rome, Italy
| | - Deborah M Eastwood
- Department of Orthopaedics, Great Ormond St Hospital for Children, Orthopaedics, London, UK.,The Catterall Unit Royal National Orthopaedic Hospital NHS Trust, Stanmore, UK
| | - Martin Biosse Duplan
- Dental School, Université Paris Descartes Sorbonne Paris Cité, Montrouge, France.,APHP, Department of Odontology, Bretonneau Hospital, Paris, France.,APHP, Reference Center for Rare Diseases of Calcium and Phosphate Metabolism, and Filière OSCAR, Paris, France
| | - Justine Bacchetta
- Department of Pediatric Nephrology, Rheumatology and Dermatology, University Children's Hospital, Lyon, France
| | - Dirk Schnabel
- Center for Chronic Sick Children, Pediatric Endocrinology, Charitè, University Medicine, Berlin, Germany
| | - Philippe Wicart
- APHP, Reference Center for Rare Diseases of Calcium and Phosphate Metabolism, and Filière OSCAR, Paris, France.,APHP, Department of Pediatric Orthopedic Surgery, Necker - Enfants Malades University Hospital, Paris, France.,Paris Descartes University, Paris, France
| | - Detlef Bockenhauer
- University College London, Centre for Nephrology and Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Fernando Santos
- Hospital Universitario Central de Asturias (HUCA), University of Oviedo, Oviedo, Spain
| | - Elena Levtchenko
- Department of Pediatric Nephrology and Development and Regeneration, University Hospitals Leuven, University of Leuven, Leuven, Belgium
| | - Pol Harvengt
- RVRH-XLH, French Patient Association for XLH, Suresnes, France
| | - Martha Kirchhoff
- Phosphatdiabetes e.V., German Patient Association for XLH, Lippstadt, Germany
| | - Federico Di Rocco
- Pediatric Neurosurgery, Hôpital Femme Mère Enfant, Centre de Référence Craniosténoses, Université de Lyon, Lyon, France
| | - Catherine Chaussain
- Dental School, Université Paris Descartes Sorbonne Paris Cité, Montrouge, France.,APHP, Department of Odontology, Bretonneau Hospital, Paris, France.,APHP, Reference Center for Rare Diseases of Calcium and Phosphate Metabolism, and Filière OSCAR, Paris, France
| | - Maria Louisa Brandi
- Metabolic Bone Diseases Unit, Department of Surgery and Translational Medicine, University of Florence, Florence, Italy
| | - Lars Savendahl
- Pediatric Endocrinology Unit, Karolinska University Hospital, Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden
| | - Karine Briot
- APHP, Reference Center for Rare Diseases of Calcium and Phosphate Metabolism, and Filière OSCAR, Paris, France.,Paris Descartes University, Paris, France.,APHP, Department of Rheumatology, Cochin Hospital, Paris, France.,INSERM UMR-1153, Paris, France
| | - Peter Kamenicky
- APHP, Reference Center for Rare Diseases of Calcium and Phosphate Metabolism, and Filière OSCAR, Paris, France.,APHP, Department of Endocrinology and Reproductive Diseases, Bicêtre Paris-Sud Hospital, Paris, France.,INSERM U1185, Bicêtre Paris-Sud, Paris-Sud - Paris Saclay University, Le Kremlin-Bicêtre, France
| | - Lars Rejnmark
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Agnès Linglart
- APHP, Reference Center for Rare Diseases of Calcium and Phosphate Metabolism, and Filière OSCAR, Paris, France.,INSERM U1185, Bicêtre Paris-Sud, Paris-Sud - Paris Saclay University, Le Kremlin-Bicêtre, France.,APHP, Platform of Expertise of Paris-Sud for Rare Diseases and Filière OSCAR, Bicêtre Paris-Sud Hospital (HUPS), Le Kremlin-Bicêtre, France.,APHP, Endocrinology and Diabetes for Children, Bicêtre Paris-Sud Hospital, Le Kremlin-Bicêtre, France
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21
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Rothenbuhler A, Schnabel D, Högler W, Linglart A. Diagnosis, treatment-monitoring and follow-up of children and adolescents with X-linked hypophosphatemia (XLH). Metabolism 2020; 103S:153892. [PMID: 30928313 DOI: 10.1016/j.metabol.2019.03.009] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Revised: 03/22/2019] [Accepted: 03/25/2019] [Indexed: 11/19/2022]
Abstract
Early diagnosis, optimal therapeutic management and regular follow up of children with X-linked hypophosphatemia (XLH) determine their long term outcomes and future quality of life. Biochemical screening of potentially affected newborns in familial cases and improving physician's knowledge on clinical signs, symptoms and biochemical characteristics of XLH for de novo cases should lead to earlier diagnosis and treatment initiation. The follow-up of children with XLH includes clinical, biochemical and radiological monitoring of treatment (efficacy and complications) and screening for XLH-related dental, neurosurgical, rheumatological, cardiovascular, renal and ENT complications. In 2018, the European Union approved the use of burosumab, a humanized monoclonal anti-FGF23 antibody, as an alternative therapy to conventional therapy (active vitamin D analogues and phosphate supplements) in growing children with XLH and insufficiently controlled disease. Diagnostic criteria of XLH and the principles of disease management with conventional treatment or with burosumab are reviewed in this paper.
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Affiliation(s)
- Anya Rothenbuhler
- APHP, Endocrinology and Diabetology for Children, Bicêtre Paris Sud Hospital, Le Kremlin-Bicêtre, France; APHP, Reference Center for Rare Disorders of Calcium and Phosphate Metabolism, filière OSCAR, Paris, France; APHP, Platform of Expertise for Rare Disorders Paris-Sud, Bicêtre Paris Sud Hospital, Le Kremlin-Bicêtre, France.
| | - Dirk Schnabel
- Center for Chronic Sick Children, Pediatric Endocrinology, Charité, University Medicine Berlin, Germany
| | - Wolfgang Högler
- Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, United Kingdom; Department of Pediatrics and Adolescent Medicine, Johannes Kepler University Linz, Linz, Austria
| | - Agnès Linglart
- APHP, Endocrinology and Diabetology for Children, Bicêtre Paris Sud Hospital, Le Kremlin-Bicêtre, France; APHP, Reference Center for Rare Disorders of Calcium and Phosphate Metabolism, filière OSCAR, Paris, France; APHP, Platform of Expertise for Rare Disorders Paris-Sud, Bicêtre Paris Sud Hospital, Le Kremlin-Bicêtre, France
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22
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Lecoq AL, Brandi ML, Linglart A, Kamenický P. Management of X-linked hypophosphatemia in adults. Metabolism 2020; 103S:154049. [PMID: 31863781 DOI: 10.1016/j.metabol.2019.154049] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Revised: 10/23/2019] [Accepted: 11/25/2019] [Indexed: 11/27/2022]
Abstract
X-linked hypophosphatemia (XLH) is caused by mutations in the PHEX gene which result in Fibroblast Growth Factor-23 (FG-F23) excess and phosphate wasting. Clinically, XLH children present with rickets, bone deformities and short stature. In adulthood, patients may still be symptomatic with bone and joint pain, osteomalacia-related fractures or pseudofractures, precocious osteoarthrosis, enthesopathy, muscle weakness and severe dental anomalies. Besides these musculoskeletal and dental manifestations, adult XLH patients are also prone to secondary and tertiary hyperparathyroidism, cardiovascular and metabolic disorders. Pathophysiology of hyperparathyroidism is only partially understood but FGF23 excess and deficient production of calcitriol likely contributes to its development. Similarly, the pathophysiological mechanisms of potential cardiovascular and metabolic involvements are not clear, but FGF-23 excess may play an essential role. Treatment should be considered in symptomatic patients, patients undergoing orthopedic or dental surgery and women during pregnancy and lactation. Treatment with oral phosphate salts and active vitamin D analogs has incomplete efficacy and potential risks. Burosumab, a recombinant human monoclonal antibody against FGF-23, has proven its efficacy in phase 2 and phase 3 clinical trials in adult patients with XLH, but currently its position as first line or second line treatment differ among the countries.
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Affiliation(s)
- Anne-Lise Lecoq
- AP-HP, Department of Endocrinology and Reproductive Diseases, Reference Center for Rare Disorders of Calcium and Phosphate Metabolism, filière OSCAR, and Platform of Expertise for Rare Disorders, Bicêtre Paris Saclay Hospital, Le Kremlin-Bicêtre, France
| | - Maria Luisa Brandi
- Department of Surgery and Translational Medicine, University of Florence, University Hospital of Florence, Florence, Italy
| | - Agnès Linglart
- AP-HP, Endocrinology and Diabetes for Children, Reference Center for Rare Disorders of Calcium and Phosphate Metabolism, filière OSCAR, and Platform of Expertise for Rare Disorders, Bicêtre Paris Saclay Hospital, Le Kremlin-Bicêtre, France; Université Paris-Saclay, INSERM, Physiologie et Physiopathologie Endocriniennes, Le Kremlin-Bicêtre, France
| | - Peter Kamenický
- AP-HP, Department of Endocrinology and Reproductive Diseases, Reference Center for Rare Disorders of Calcium and Phosphate Metabolism, filière OSCAR, and Platform of Expertise for Rare Disorders, Bicêtre Paris Saclay Hospital, Le Kremlin-Bicêtre, France; Université Paris-Saclay, INSERM, Physiologie et Physiopathologie Endocriniennes, Le Kremlin-Bicêtre, France.
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23
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Schindeler A, Biggin A, Munns CF. Clinical Evidence for the Benefits of Burosumab Therapy for X-Linked Hypophosphatemia (XLH) and Other Conditions in Adults and Children. Front Endocrinol (Lausanne) 2020; 11:338. [PMID: 32547492 PMCID: PMC7271822 DOI: 10.3389/fendo.2020.00338] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 04/29/2020] [Indexed: 12/14/2022] Open
Abstract
Burosumab (KRN23) is an FGF23 neutralizing antibody that has been the subject of several recent clinical trials principally focused on the treatment of hypophosphatemic rickets in patients with X-linked hypophosphatemia (XLH). Since the first publications in 2014, these trials have demonstrated efficacy with minimal safety concerns in both adult and pediatric cohorts. These studies have used dose-escalation to establish a dosing regimen that is well-tolerated in clinical use. This review summarizes the clinical trial data with respect to burosumab treatment in adults and children as well as noting several clinical trials currently underway. While burosumab appears transformative for the treatment of XLH, long term follow-up studies would be required to allay concerns over the potential for nephrocalcinosis and cardiac calcification. While these do not appear to be problematic in current trials, the effects of chronic or lifelong treatment have yet to be established.
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Affiliation(s)
- Aaron Schindeler
- Bioengineering and Molecular Medicine Laboratory, The Children's Hospital at Westmead, Westmead, NSW, Australia
- Discipline of Child and Adolescent Health, University of Sydney, Sydney, NSW, Australia
| | - Andrew Biggin
- Discipline of Child and Adolescent Health, University of Sydney, Sydney, NSW, Australia
- Department of Endocrinology and Diabetes, The Children's Hospital at Westmead, Westmead, NSW, Australia
| | - Craig F. Munns
- Discipline of Child and Adolescent Health, University of Sydney, Sydney, NSW, Australia
- Department of Endocrinology and Diabetes, The Children's Hospital at Westmead, Westmead, NSW, Australia
- *Correspondence: Craig F. Munns
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24
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Imel EA, Biggin A, Schindeler A, Munns CF. FGF23, Hypophosphatemia, and Emerging Treatments. JBMR Plus 2019; 3:e10190. [PMID: 31485552 PMCID: PMC6715782 DOI: 10.1002/jbm4.10190] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/29/2018] [Revised: 02/13/2019] [Accepted: 02/26/2019] [Indexed: 01/03/2023] Open
Abstract
FGF23 is an important hormonal regulator of phosphate homeostasis. Together with its co-receptor Klotho, it modulates phosphate reabsorption and both 1α-hydroxylation and 24-hydroxylation in the renal proximal tubules. The most common FGF23-mediated hypophosphatemia is X-linked hypophosphatemia (XLH), caused by mutations in the PHEX gene. FGF23-mediated forms of hypophosphatemia are characterized by phosphaturia and low or low-normal calcitriol concentrations, and unlike nutritional rickets, these cannot be cured with nutritional vitamin D supplementation. Autosomal dominant and autosomal recessive forms of FGF23-mediated hypophosphatemias show a similar pathophysiology, despite a variety of different underlying genetic causes. An excess of FGF23 activity has also been associated with a number of other conditions causing hypophosphatemia, including tumor-induced osteomalacia, fibrous dysplasia of the bone, and cutaneous skeletal hypophosphatemia syndrome. Historically phosphate supplementation and therapy using analogs of highly active vitamin D (eg, calcitriol, alfacalcidol, paricalcitol, eldecalcitol) have been used to manage conditions involving hypophosphatemia; however, recently a neutralizing antibody for FGF23 (burosumab) has emerged as a promising treatment agent for FGF23-mediated disorders. This review discusses the progression of clinical trials for burosumab for the treatment of XLH and its recent availability for clinical use. Burosumab may have potential for treating other conditions associated with FGF23 overactivity, but these are not yet supported by trial data. © 2019 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.
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Affiliation(s)
- Erik A Imel
- Division of EndocrinologyIndiana University School of Medicine, Indianapolis, INUSA
| | - Andrew Biggin
- The University of Sydney Children's Hospital Westmead Clinical School, University of SydneySydneyAustralia
- Department of EndocrinologyThe Children's Hospital at WestmeadWestmeadAustralia
| | - Aaron Schindeler
- The University of Sydney Children's Hospital Westmead Clinical School, University of SydneySydneyAustralia
- Orthopaedic Research Unit, The Children's Hospital at WestmeadWestmeadAustralia
| | - Craig F Munns
- The University of Sydney Children's Hospital Westmead Clinical School, University of SydneySydneyAustralia
- Department of EndocrinologyThe Children's Hospital at WestmeadWestmeadAustralia
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25
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McKenna MJ, Martin-Grace J, Crowley R, Twomey PJ, Kilbane MT. Congenital hypophosphataemia in adults: determinants of bone turnover markers and amelioration of renal phosphate wasting following total parathyroidectomy. J Bone Miner Metab 2019; 37:685-693. [PMID: 30238432 DOI: 10.1007/s00774-018-0957-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Accepted: 09/03/2018] [Indexed: 01/08/2023]
Abstract
Congenital hypophosphataemia (CH) is a collection of disorders that cause defective bone mineralisation manifesting with rickets in childhood and osteomalacia in adulthood. Bone turnover markers (BTMs) are surrogate measures of metabolic bone disease severity. We explored the utility of BTMs in 27 adults with CH: 23 had X-linked hypophosphataemia (XLH), of whom 2 were hypoparathyroid post-total parathyroidectomy (PTx); 2 had autosomal dominant hypophosphataemic rickets (ADHR), and 2 had none of the known mutations. We measured the renal tubular maximum reabsorption rate of phosphate (TmP/GFR), C-terminal fibroblast growth factor 23 (FGF23), parathyroid hormone (PTH), ionised calcium, 1,25-dihydroxyvitamin D [1,25(OH)2D], and a panel of BTMs: serum bone-specific alkaline phosphatase (bone ALP), osteocalcin (Oc), total procollagen type I amino-terminal propeptide (PINP), and carboxy-terminal telopeptide of type I collagen (CTX); and urine amino-terminal telopeptides of type I collagen (uNTX). After excluding 2 patients with XLH and PTx, the frequency of abnormal elevation in BTMs was: bone ALP (96%); CTX (72%); PINP (52%); uNTX (48%); Oc (28%). The strongest association with bone ALP was TmP/GFR. Those patients receiving phosphate supplements and alfacalcidol had significant elevation in CTX. The 2 patients with XLH and PTx had normalisation of TmP/GFR and near normalisation of BTMs post-operatively, despite marked elevation in both C-terminal and intact FGF23. In conclusion, BTMs in our CH patients indicated that most have abnormalities consistent with osteomalacia and many have mild secondary hyperparathyroidism; and the normalisation of TmP/GFR after total PTx in 2 cases of XLH remains unexplained, but possible causes are speculated.
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Affiliation(s)
- Malachi J McKenna
- Department of Endocrinology, St. Vincent's University Hospital, Elm Park, Dublin 4, D04T6F4, Ireland.
- UCD School of Medicine and Medical Science, University College Dublin, Dublin, Ireland.
| | - Julie Martin-Grace
- Department of Endocrinology, St. Vincent's University Hospital, Elm Park, Dublin 4, D04T6F4, Ireland
| | - Rachel Crowley
- Department of Endocrinology, St. Vincent's University Hospital, Elm Park, Dublin 4, D04T6F4, Ireland
- UCD School of Medicine and Medical Science, University College Dublin, Dublin, Ireland
| | - Patrick J Twomey
- UCD School of Medicine and Medical Science, University College Dublin, Dublin, Ireland
- Department of Clinical Chemistry, St. Vincent's University Hospital, Dublin, Ireland
| | - Mark T Kilbane
- UCD School of Medicine and Medical Science, University College Dublin, Dublin, Ireland
- Department of Clinical Chemistry, St. Vincent's University Hospital, Dublin, Ireland
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26
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Larsen P, Vedel JO, Vistrup S, Elsoe R. Long-Lasting Hyperalgesia Is Common in Patients Following Patella Fractures. PAIN MEDICINE 2019; 19:429-437. [PMID: 29566207 DOI: 10.1093/pm/pnx144] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Background The objective was to investigate the long-term development of pain and hyperalgesia after patella fractures. The secondary objective was to report the association between tibiofemoral and patellofemoral osteoarthritis, pain, and hyperalgesia. Methods The study used a cohort design. Patients who were treated for patella fractures between January 2006 and December 2009 were identified. Patients age 20 to 78 years were included. The main outcome was the pain pressure threshold (PPT). Moreover, visual analog scale (VAS) for pain, radiological outcomes of patellofemoral and tibiofemoral osteoarthritis, and the pain subscale of the WOMAC and EQ-5D questionnaires were used. Results Forty-nine patients were included, with a mean age of 53.9 years and a mean follow-up time of 8.5 years. The injured knee region showed significantly decreased PPT levels (P < 0.046), but decreases in PPT were not found for the forearm region (P = 0.24). The VAS score for the worst pain during the last 24 hours was reported, with a mean of 2.9 ± 2.4 cm. The EQ-5D-5L-pain scale was reported, with a mean score of 2.4 (95% confidence interval [CI] = 2.0-2.7). The WOMAC Pain score was reported, with a mean score of 3.9 (95% CI = 2.8-4.9). Moderate correlations were found between the VAS scores and PPT levels (R = 0.428, P = 0.002). Weak correlations were found between VAS scores and PPT levels for site 7 (forearm; R = 0.313, P = 0.03). Conclusions The present study suggests that long-lasting local hyperalgesia following a patella fracture is common. No side-to-side difference at the forearms were observed, indicating that the observed local hyperalgesia was not part of a generalized sensitization.
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Affiliation(s)
- Peter Larsen
- Department of Occupational Therapy and Physiotherapy
| | - Julie Odgaard Vedel
- Department of Orthopaedic Surgery, Aalborg University Hospital, Aalborg, Denmark
| | - Sabina Vistrup
- Department of Orthopaedic Surgery, Aalborg University Hospital, Aalborg, Denmark
| | - Rasmus Elsoe
- Department of Orthopaedic Surgery, Aalborg University Hospital, Aalborg, Denmark
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27
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Beck-Nielsen SS, Mughal Z, Haffner D, Nilsson O, Levtchenko E, Ariceta G, de Lucas Collantes C, Schnabel D, Jandhyala R, Mäkitie O. FGF23 and its role in X-linked hypophosphatemia-related morbidity. Orphanet J Rare Dis 2019; 14:58. [PMID: 30808384 PMCID: PMC6390548 DOI: 10.1186/s13023-019-1014-8] [Citation(s) in RCA: 143] [Impact Index Per Article: 28.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Accepted: 01/30/2019] [Indexed: 12/29/2022] Open
Abstract
Background X-linked hypophosphatemia (XLH) is an inherited disease of phosphate metabolism in which inactivating mutations of the Phosphate Regulating Endopeptidase Homolog, X-Linked (PHEX) gene lead to local and systemic effects including impaired growth, rickets, osteomalacia, bone abnormalities, bone pain, spontaneous dental abscesses, hearing difficulties, enthesopathy, osteoarthritis, and muscular dysfunction. Patients with XLH present with elevated levels of fibroblast growth factor 23 (FGF23), which is thought to mediate many of the aforementioned manifestations of the disease. Elevated FGF23 has also been observed in many other diseases of hypophosphatemia, and a range of animal models have been developed to study these diseases, yet the role of FGF23 in the pathophysiology of XLH is incompletely understood. Methods The role of FGF23 in the pathophysiology of XLH is here reviewed by describing what is known about phenotypes associated with various PHEX mutations, animal models of XLH, and non-nutritional diseases of hypophosphatemia, and by presenting molecular pathways that have been proposed to contribute to manifestations of XLH. Results The pathophysiology of XLH is complex, involving a range of molecular pathways that variously contribute to different manifestations of the disease. Hypophosphatemia due to elevated FGF23 is the most obvious contributor, however localised fluctuations in tissue non-specific alkaline phosphatase (TNAP), pyrophosphate, calcitriol and direct effects of FGF23 have been observed to be associated with certain manifestations. Conclusions By describing what is known about these pathways, this review highlights key areas for future research that would contribute to the understanding and clinical treatment of non-nutritional diseases of hypophosphatemia, particularly XLH.
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Affiliation(s)
| | - Zulf Mughal
- Royal Manchester Children's Hospital, Manchester, UK
| | | | - Ola Nilsson
- Karolinska Institutet, Stockholm, Sweden and Örebro University, Örebro, Sweden
| | | | - Gema Ariceta
- Hospital Universitario Materno-Infantil Vall d'Hebron, Universitat Autonoma de Barcelona, Barcelona, Spain
| | | | - Dirk Schnabel
- University Children's Hospital of Berlin, Berlin, Germany
| | | | - Outi Mäkitie
- Children's Hospital, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
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Marcucci G, Masi L, Ferrarì S, Haffner D, Javaid MK, Kamenický P, Reginster JY, Rizzoli R, Brandi ML. Phosphate wasting disorders in adults. Osteoporos Int 2018; 29:2369-2387. [PMID: 30014155 DOI: 10.1007/s00198-018-4618-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Accepted: 06/19/2018] [Indexed: 12/14/2022]
Abstract
A cause of hypophosphatemia is phosphate wasting disorders. Knowledge concerning mechanisms involved in phosphate wasting disorders has greatly increased in the last decade by the identification of phosphatonins, among them FGF-23. FGF-23 is a primarily bone derived factor decreasing renal tubular reabsorption of phosphate and the synthesis of calcitriol. Currently, pharmacological treatment of these disorders offers limited efficacy and is potentially associated to gastrointestinal, renal, and parathyroid complications; therefore, efforts have been directed toward newer pharmacological strategies that target the FGF-23 pathway. This review focuses on phosphate metabolism, its main regulators, and phosphate wasting disorders in adults, highlighting the main issues related to diagnosis and current and new potential treatments.
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Affiliation(s)
- G Marcucci
- Metabolic Bone Diseases Unit, Department of Surgery and Translational Medicine, University of Florence, Florence, Italy
| | - L Masi
- Metabolic Bone Diseases Unit, Department of Surgery and Translational Medicine, University of Florence, Florence, Italy
| | - S Ferrarì
- Division of Bone Diseases, Geneva University Hospitals and Faculty of Medicine, Geneva, Switzerland
| | - D Haffner
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Hannover Medical School, Hannover, Germany
| | - M K Javaid
- Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, UK
| | - P Kamenický
- Service d'Endocrinologie et des Maladies de la Reproduction, Centre de référence des Maladies Rares du métabolisme du calcium et du phosphore, Hopital de Bicêtre - AP-HP, 94275, Le Kremlin-Bicêtre, France
| | - J-Y Reginster
- Department of Public Health, Epidemiology and Health Economics, University of Liège, Liège, Belgium
| | - R Rizzoli
- Division of Bone Diseases, Geneva University Hospitals and Faculty of Medicine, Geneva, Switzerland
| | - M L Brandi
- Metabolic Bone Diseases Unit, Department of Surgery and Translational Medicine, University of Florence, Florence, Italy.
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Cardoso AL, Fernandes A, Aguilar-Pimentel JA, de Angelis MH, Guedes JR, Brito MA, Ortolano S, Pani G, Athanasopoulou S, Gonos ES, Schosserer M, Grillari J, Peterson P, Tuna BG, Dogan S, Meyer A, van Os R, Trendelenburg AU. Towards frailty biomarkers: Candidates from genes and pathways regulated in aging and age-related diseases. Ageing Res Rev 2018; 47:214-277. [PMID: 30071357 DOI: 10.1016/j.arr.2018.07.004] [Citation(s) in RCA: 279] [Impact Index Per Article: 46.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Revised: 07/08/2018] [Accepted: 07/10/2018] [Indexed: 12/12/2022]
Abstract
OBJECTIVE Use of the frailty index to measure an accumulation of deficits has been proven a valuable method for identifying elderly people at risk for increased vulnerability, disease, injury, and mortality. However, complementary molecular frailty biomarkers or ideally biomarker panels have not yet been identified. We conducted a systematic search to identify biomarker candidates for a frailty biomarker panel. METHODS Gene expression databases were searched (http://genomics.senescence.info/genes including GenAge, AnAge, LongevityMap, CellAge, DrugAge, Digital Aging Atlas) to identify genes regulated in aging, longevity, and age-related diseases with a focus on secreted factors or molecules detectable in body fluids as potential frailty biomarkers. Factors broadly expressed, related to several "hallmark of aging" pathways as well as used or predicted as biomarkers in other disease settings, particularly age-related pathologies, were identified. This set of biomarkers was further expanded according to the expertise and experience of the authors. In the next step, biomarkers were assigned to six "hallmark of aging" pathways, namely (1) inflammation, (2) mitochondria and apoptosis, (3) calcium homeostasis, (4) fibrosis, (5) NMJ (neuromuscular junction) and neurons, (6) cytoskeleton and hormones, or (7) other principles and an extensive literature search was performed for each candidate to explore their potential and priority as frailty biomarkers. RESULTS A total of 44 markers were evaluated in the seven categories listed above, and 19 were awarded a high priority score, 22 identified as medium priority and three were low priority. In each category high and medium priority markers were identified. CONCLUSION Biomarker panels for frailty would be of high value and better than single markers. Based on our search we would propose a core panel of frailty biomarkers consisting of (1) CXCL10 (C-X-C motif chemokine ligand 10), IL-6 (interleukin 6), CX3CL1 (C-X3-C motif chemokine ligand 1), (2) GDF15 (growth differentiation factor 15), FNDC5 (fibronectin type III domain containing 5), vimentin (VIM), (3) regucalcin (RGN/SMP30), calreticulin, (4) PLAU (plasminogen activator, urokinase), AGT (angiotensinogen), (5) BDNF (brain derived neurotrophic factor), progranulin (PGRN), (6) α-klotho (KL), FGF23 (fibroblast growth factor 23), FGF21, leptin (LEP), (7) miRNA (micro Ribonucleic acid) panel (to be further defined), AHCY (adenosylhomocysteinase) and KRT18 (keratin 18). An expanded panel would also include (1) pentraxin (PTX3), sVCAM/ICAM (soluble vascular cell adhesion molecule 1/Intercellular adhesion molecule 1), defensin α, (2) APP (amyloid beta precursor protein), LDH (lactate dehydrogenase), (3) S100B (S100 calcium binding protein B), (4) TGFβ (transforming growth factor beta), PAI-1 (plasminogen activator inhibitor 1), TGM2 (transglutaminase 2), (5) sRAGE (soluble receptor for advanced glycosylation end products), HMGB1 (high mobility group box 1), C3/C1Q (complement factor 3/1Q), ST2 (Interleukin 1 receptor like 1), agrin (AGRN), (6) IGF-1 (insulin-like growth factor 1), resistin (RETN), adiponectin (ADIPOQ), ghrelin (GHRL), growth hormone (GH), (7) microparticle panel (to be further defined), GpnmB (glycoprotein nonmetastatic melanoma protein B) and lactoferrin (LTF). We believe that these predicted panels need to be experimentally explored in animal models and frail cohorts in order to ascertain their diagnostic, prognostic and therapeutic potential.
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Imel EA, White KE. Pharmacological management of X-linked hypophosphataemia. Br J Clin Pharmacol 2018; 85:1188-1198. [PMID: 30207609 DOI: 10.1111/bcp.13763] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 09/05/2018] [Accepted: 09/05/2018] [Indexed: 12/25/2022] Open
Abstract
The most common heritable disorder of renal phosphate wasting, X-linked hypophosphataemia (XLH), was discovered to be caused by inactivating mutations in the phosphate regulating gene with homology to endopeptidases on the X-chromosome (PHEX) gene in 1995. Although the exact molecular mechanisms by which PHEX mutations cause disturbed phosphate handling in XLH remain unknown, focus for novel therapies has more recently been based upon the finding that the bone-produced phosphaturic hormone fibroblast growth factor-23 is elevated in XLH patient plasma. Previous treatment strategies for XLH were based upon phosphate repletion plus active vitamin D analogues, which are difficult to manage, fail to address the primary pathogenesis of the disease, and can have deleterious side effects. A novel therapy for XLH directly targeting fibroblast growth factor-23 via a humanized monoclonal antibody (burosumab-twza/CRYSVITA, henceforth referred to just as burosumab) has emerged as an effective, and recently approved, pharmacological treatment for both children and adults. This review will provide an overview of the clinical manifestations of XLH, the molecular pathophysiology, and summarize its current treatment.
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Affiliation(s)
- Erik A Imel
- Department of Medicine, Division of Endocrinology and Metabolism, Indiana University School of Medicine, Indianapolis, IN, USA.,Department of Pediatrics, Section of Endocrinology and Diabetology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Kenneth E White
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, USA.,Department of Medicine, Division of Nephrology, Indiana University School of Medicine, Indianapolis, IN, USA
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Lyseng-Williamson KA. Burosumab in X-linked hypophosphatemia: a profile of its use in the USA. DRUGS & THERAPY PERSPECTIVES 2018; 34:497-506. [PMID: 30459508 PMCID: PMC6223702 DOI: 10.1007/s40267-018-0560-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Burosumab (Crysvita®), a fully human IgG1 monoclonal antibody directed at fibroblast growth factor 23 (FGF23), is indicated for the treatment of X-linked hypophosphatemia (XLH), a condition associated with excessive FGF23 production. It directly addresses the excessive FGF23 activity in patients with XLH by binding to FGF23, and inhibiting its signaling. This leads to increased gastrointestinal phosphate absorption and renal phosphate reabsorption, thereby improving serum phosphate levels, and, ultimately, bone mineralization and the risk of bone disease. In clinical trials, subcutaneous burosumab increased serum phosphorus levels in pediatric and adult patients with XLH, as well as significantly improving the severity of rickets in children, and improving pain, stiffness, physical functioning, and fracture/pseudofracture healing in adults. Burosumab is well tolerated by children and adults with XLH, with most treatment-emergent adverse events being of mild to moderate severity.
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Avin KG, Vallejo JA, Chen NX, Wang K, Touchberry CD, Brotto M, Dallas SL, Moe SM, Wacker MJ. Fibroblast growth factor 23 does not directly influence skeletal muscle cell proliferation and differentiation or ex vivo muscle contractility. Am J Physiol Endocrinol Metab 2018; 315:E594-E604. [PMID: 29558205 PMCID: PMC6230710 DOI: 10.1152/ajpendo.00343.2017] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 01/29/2018] [Accepted: 02/15/2018] [Indexed: 02/06/2023]
Abstract
Skeletal muscle dysfunction accompanies the clinical disorders of chronic kidney disease (CKD) and hereditary hypophosphatemic rickets. In both disorders, fibroblast growth factor 23 (FGF23), a bone-derived hormone regulating phosphate and vitamin D metabolism, becomes chronically elevated. FGF23 has been shown to play a direct role in cardiac muscle dysfunction; however, it is unknown whether FGF23 signaling can also directly induce skeletal muscle dysfunction. We found expression of potential FGF23 receptors ( Fgfr1-4) and α-Klotho in muscles of two animal models (CD-1 and Cy/+ rat, a naturally occurring rat model of chronic kidney disease-mineral bone disorder) as well as C2C12 myoblasts and myotubes. C2C12 proliferation, myogenic gene expression, oxidative stress marker 8-OHdG, intracellular Ca2+ ([Ca2+]i), and ex vivo contractility of extensor digitorum longus (EDL) or soleus muscles were assessed after treatment with various amounts of FGF23. FGF23 (2-100 ng/ml) did not alter C2C12 proliferation, expression of myogenic genes, or oxidative stress after 24- to 72-h treatment. Acute or prolonged FGF23 treatment up to 6 days did not alter C2C12 [Ca2+]i handling, nor did acute treatment with FGF23 (9-100 ng/ml) affect EDL and soleus muscle contractility. In conclusion, although skeletal muscles express the receptors involved in FGF23-mediated signaling, in vitro FGF23 treatments failed to directly alter skeletal muscle development or function under the conditions tested. We hypothesize that other endogenous substances may be required to act in concert with FGF23 or apart from FGF23 to promote muscle dysfunction in hereditary hypophosphatemic rickets and CKD.
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Affiliation(s)
- Keith G Avin
- Department of Physical Therapy, School of Health and Rehabilitation Sciences, Indiana University , Indianapolis, Indiana
- Division of Nephrology, Department of Medicine, Indiana University School of Medicine , Indianapolis, Indiana
| | - Julian A Vallejo
- Department of Biomedical Sciences, School of Medicine, University of Missouri-Kansas City , Kansas City, Missouri
- Department of Oral and Craniofacial Sciences, School of Dentistry, University of Missouri-Kansas City , Kansas City, Missouri
| | - Neal X Chen
- Division of Nephrology, Department of Medicine, Indiana University School of Medicine , Indianapolis, Indiana
| | - Kun Wang
- Department of Oral and Craniofacial Sciences, School of Dentistry, University of Missouri-Kansas City , Kansas City, Missouri
| | - Chad D Touchberry
- Department of Biomedical Sciences, School of Medicine, University of Missouri-Kansas City , Kansas City, Missouri
| | - Marco Brotto
- College of Nursing and Health Innovation, Bone-Muscle Collaborative Sciences, University of Texas-Arlington , Arlington, Texas
| | - Sarah L Dallas
- Department of Oral and Craniofacial Sciences, School of Dentistry, University of Missouri-Kansas City , Kansas City, Missouri
| | - Sharon M Moe
- Division of Nephrology, Department of Medicine, Indiana University School of Medicine , Indianapolis, Indiana
- Roudebush Veterans Administration Medical Center , Indianapolis, Indiana
| | - Michael J Wacker
- Department of Biomedical Sciences, School of Medicine, University of Missouri-Kansas City , Kansas City, Missouri
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33
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Mohammed MA, Rady SA, Mohammed RA, Fadda SM. Relation of plasma fibroblast growth factor-23 (FGF-23) to radiographic severity in primary knee osteoarthritis patients. EGYPTIAN RHEUMATOLOGIST 2018. [DOI: 10.1016/j.ejr.2018.01.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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Xiao L, Homer-Bouthiette C, Hurley MM. FGF23 Neutralizing Antibody Partially Improves Bone Mineralization Defect of HMWFGF2 Isoforms in Transgenic Female Mice. J Bone Miner Res 2018; 33:1347-1361. [PMID: 29502359 PMCID: PMC11034775 DOI: 10.1002/jbmr.3417] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 02/20/2018] [Accepted: 02/28/2018] [Indexed: 01/12/2023]
Abstract
Mice overexpressing high molecular weight FGF2 isoforms (HMWTg) in osteoblast lineage phenocopy human X-linked hypophosphatemic rickets (XLH) and a Hyp murine model of XLH demonstrating increased FGF23/FGF receptor signaling and hypophosphatemic rickets/osteomalacia. Because HMWFGF2 was upregulated in bones of Hyp mice and abnormal FGF23 signaling is important in XLH, HMWTg mice were used to examine the effect of the FGF23 neutralizing antibody (FGF23Ab). Eight-week-old female Vector control mice and HMWTg mice were treated with FGF23Ab or control IgG. A single injection of FGF23Ab rescued abnormal hypophosphatemia in HMWTg. The decreased type II sodium-dependent phosphate co-transporter (Npt2a) was rescued by FGF23Ab treatment. Inappropriately low serum 1,25(OH)2 D in HMWTg mice was normalized by FGF23Ab treatment, which is accompanied by increased anabolic vitamin D hydroxylase Cyp27b1 and decreased catabolic vitamin D hydroxylase Cyp24 mRNA in kidney. Long-term treatment with FGF23Ab normalized femur length and significantly increased vertebrae BMD and BMC, and femur BMC in HMWTg mice compared to IgG-treated HMWTg mice. Micro-computed tomography (μCT) revealed increased cortical porosity and decreased cortical apparent density in the HMWTg-IgG group compared with the Vector-IgG group; however, FGF23Ab treatment rescued defective cortical mineralization, decreased porosity, and increased apparent density in HMWTg mice. Bone histomorphometry analysis showed FGF23Ab treatment decreased osteoid volume, increased intra-label thickness, mineralization apposition rate, and bone formation rate in HMWTg mice. FGF23Ab improved disorganized double labeling in femurs from HMWTg mice. Quantitative real-time PCR analysis of tibia shafts showed FGF23Ab treatment normalized the osteocalcin (Ocn) mRNA expression in HMWTg mice, but further increased expression of SIBLING protein-related and pyrophosphate-related genes that are important in matrix mineralization, suggesting that HMWFGF2 modulates these genes independent of FGF23. We conclude that FGF23Ab partially rescued hypophosphatemic osteomalacia in HMWTg. However, long-term treatment with FGF23Ab further increased SIBLING protein-related genes and pyrophosphate-related genes in bone that could contribute to incomplete rescue of the mineralization defect. © 2018 American Society for Bone and Mineral Research.
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Affiliation(s)
- Liping Xiao
- Department of Medicine, University of Connecticut School of Medicine, UCONN Health, Farmington, CT, USA
| | - Collin Homer-Bouthiette
- Department of Medicine, University of Connecticut School of Medicine, UCONN Health, Farmington, CT, USA
| | - Marja M Hurley
- Department of Medicine, University of Connecticut School of Medicine, UCONN Health, Farmington, CT, USA
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Meo Burt P, Xiao L, Hurley MM. FGF23 Regulates Wnt/β-Catenin Signaling-Mediated Osteoarthritis in Mice Overexpressing High-Molecular-Weight FGF2. Endocrinology 2018; 159:2386-2396. [PMID: 29718273 PMCID: PMC6457004 DOI: 10.1210/en.2018-00184] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Accepted: 04/21/2018] [Indexed: 12/23/2022]
Abstract
Although humans with X-linked hypophosphatemia (XLH) and the Hyp mouse, a murine homolog of XLH, are known to develop degenerative joint disease, the exact mechanism that drives the osteoarthritis (OA) phenotype remains unclear. Mice that overexpress high-molecular-weight fibroblast growth factor (FGF) 2 isoforms (HMWTg mice) phenocopy both XLH and Hyp, including OA with increased FGF23 production in bone and serum. Because HMWTg cartilage also has increased FGF23 and there is cross-talk between FGF23-Wnt/β-catenin signaling, the purpose of this study was to determine if OA observed in HMWTg mice is due to FGF23-mediated canonical Wnt signaling in chondrocytes, given that both pathways are implicated in OA pathogenesis. HMWTg OA joints had decreased Dkk1, Sost, and Lrp6 expression with increased Wnt5a, Wnt7b, Lrp5, Axin2, phospho-GSK3β, Lef1, and nuclear β-catenin, as indicated by immunohistochemistry or quantitative PCR analysis. Chondrocytes from HMWTg mice had enhanced alcian blue and alkaline phosphatase staining as well as increased FGF23, Adamts5, Il-1β, Wnt7b, Wnt16, and Wisp1 gene expression and phospho-GSK3β protein expression as indicated by Western blot, compared with chondrocytes of vector control and chondrocytes from mice overexpressing the low-molecular-weight isoform, which were protected from OA. Canonical Wnt inhibitor treatment rescued some of those parameters in HMWTg chondrocytes, seemingly delaying the initially accelerated chondrogenic differentiation. FGF23 neutralizing antibody treatment was able to partly ameliorate OA abnormalities in subchondral bone and reduce degradative/hypertrophic chondrogenic marker expression in HMWTg joints in vivo. These results demonstrate that osteoarthropathy of HMWTg is at least partially due to FGF23-modulated Wnt/β-catenin signaling in chondrocytes.
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Affiliation(s)
- Patience Meo Burt
- Division of Endocrinology and Metabolism, Department of Medicine, School of Medicine, UConn Health, Farmington, Connecticut
| | - Liping Xiao
- Division of Endocrinology and Metabolism, Department of Medicine, School of Medicine, UConn Health, Farmington, Connecticut
| | - Marja M Hurley
- Division of Endocrinology and Metabolism, Department of Medicine, School of Medicine, UConn Health, Farmington, Connecticut
- Correspondence: Marja M. Hurley, MD, Department of Medicine MC-3023, UConn Health, 263 Farmington Avenue, Farmington, Connecticut 06030. E-mail:
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Kinoshita Y, Fukumoto S. X-Linked Hypophosphatemia and FGF23-Related Hypophosphatemic Diseases: Prospect for New Treatment. Endocr Rev 2018; 39:274-291. [PMID: 29381780 DOI: 10.1210/er.2017-00220] [Citation(s) in RCA: 79] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Accepted: 01/23/2018] [Indexed: 12/21/2022]
Abstract
Phosphate plays essential roles in many biological processes, and the serum phosphate level is tightly controlled. Chronic hypophosphatemia causes impaired mineralization of the bone matrix and results in rickets and osteomalacia. Fibroblast growth factor 23 (FGF23) is a bone-derived hormone that regulates phosphate metabolism. FGF23 excess induces hypophosphatemia via impaired phosphate reabsorption in the renal proximal tubules and decreased phosphate absorption in the intestines. There are several types of genetic and acquired FGF23-related hypophosphatemic diseases. Among these diseases, X-linked hypophosphatemia (XLH), which is caused by inactivating mutations in the phosphate-regulating endopeptidase homolog, X-linked (PHEX) gene, is the most prevalent form of genetic FGF23-related hypophosphatemic rickets. Another clinically relevant form of FGF23-related hypophosphatemic disease is tumor-induced osteomalacia (TIO), a paraneoplastic syndrome associated with FGF23-producing tumors. A combination of active vitamin D and phosphate salts is the current medical therapy used to treat patients with XLH and inoperative TIO. However, this therapy has certain efficacy- and safety-associated limitations. Several measures to inhibit FGF23 activity have been considered as possible new treatments for FGF23-related hypophosphatemic diseases. In particular, a humanized monoclonal antibody for FGF23 (burosumab) is a promising treatment in patients with XLH and TIO. This review will focus on the phosphate metabolism and the pathogenesis and treatment of FGF23-related hypophosphatemic diseases.
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Affiliation(s)
- Yuka Kinoshita
- Division of Nephrology and Endocrinology, Department of Medicine, The University of Tokyo Hospital, Tokyo, Japan
| | - Seiji Fukumoto
- Fujii Memorial Institute of Medical Sciences, Institute of Advanced Medical Sciences, Tokushima University, Tokushima, Japan
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Fukumoto S. Targeting Fibroblast Growth Factor 23 Signaling with Antibodies and Inhibitors, Is There a Rationale? Front Endocrinol (Lausanne) 2018. [PMID: 29515522 PMCID: PMC5826173 DOI: 10.3389/fendo.2018.00048] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Fibroblast growth factor 23 (FGF23) is a phosphotropic hormone mainly produced by bone. FGF23 reduces serum phosphate by suppressing intestinal phosphate absorption through reducing 1,25-dihydroxyvitamin D and proximal tubular phosphate reabsorption. Excessive actions of FG23 result in several kinds of hypophosphatemic rickets/osteomalacia including X-linked hypophosphatemic rickets (XLH) and tumor-induced osteomalacia. While neutral phosphate and active vitamin D are standard therapies for child patients with XLH, these medications have several limitations both in their effects and adverse events. Several approaches that inhibit FGF23 actions including anti-FGF23 antibodies and inhibitors of FGF signaling have been shown to improve phenotypes of model mice for FG23-related hypophosphatemic diseases. In addition, clinical trials indicated that a humanized anti-FGF23 antibody increased serum phosphate and improved quality of life in patients with XLH. Furthermore, circulatory FGF23 is high in patients with chronic kidney disease (CKD). Many epidemiological studies indicated the association between high FGF23 levels and various adverse events especially in patients with CKD. However, it is not known whether the inhibition of FGF23 activities in patients with CKD is beneficial for these patients. In this review, recent findings concerning the modulation of FGF23 activities are discussed.
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Affiliation(s)
- Seiji Fukumoto
- Department of Molecular Endocrinology, Fujii Memorial Institute of Medical Sciences, Institute of Advanced Medical Sciences, Tokushima University, Tokushima, Japan
- *Correspondence: Seiji Fukumoto,
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Abstract
Rickets is a bone disease associated with abnormal serum calcium and phosphate levels. The clinical presentation is heterogeneous and depends on the age of onset and pathogenesis but includes bowing deformities of the legs, short stature and widening of joints. The disorder can be caused by nutritional deficiencies or genetic defects. Mutations in genes encoding proteins involved in vitamin D metabolism or action, fibroblast growth factor 23 (FGF23) production or degradation, renal phosphate handling or bone mineralization have been identified. The prevalence of nutritional rickets has substantially declined compared with the prevalence 200 years ago, but the condition has been re-emerging even in some well-resourced countries; prematurely born infants or breastfed infants who have dark skin types are particularly at risk. Diagnosis is usually established by medical history, physical examination, biochemical tests and radiography. Prevention is possible only for nutritional rickets and includes supplementation or food fortification with calcium and vitamin D either alone or in combination with sunlight exposure. Treatment of typical nutritional rickets includes calcium and/or vitamin D supplementation, although instances infrequently occur in which phosphate repletion may be necessary. Management of heritable types of rickets associated with defects in vitamin D metabolism or activation involves the administration of vitamin D metabolites. Oral phosphate supplementation is usually indicated for FGF23-independent phosphopenic rickets, whereas the conventional treatment of FGF23-dependent types of rickets includes a combination of phosphate and activated vitamin D; an anti-FGF23 antibody has shown promising results and is under further study.
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Abstract
Burosumab (KRN23) is a fully human monoclonal IgG1 antibody that binds excess fibroblast growth factor 23 (FGF23) and has been successfully tested in clinical trials in children with X-linked hypophosphatemic rickets. A report enclosed in this letter gives a brief review of current knowledge on burosumab therapy.
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Affiliation(s)
- Stepan Kutilek
- (1) Department of Paediatrics, Klatovy Hospital, Klatovy, Czech Republic.,(2) Department of Paediatrics, Pardubice Hospital, Pardubice, Czech Republic.,(3) Department of Paediatrics, Faculty of Medicine and Faculty Hospital in Hradec Kralove, Charles University, Hradec Kralove, Czech Republic
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