{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,29]],"date-time":"2026-10-29T16:31:40Z","timestamp":1793291500669,"version":"4.5.0"},"reference-count":21,"publisher":"The Endocrine Society","issue":"3","license":[{"start":{"date-parts":[[2021,10,12]],"date-time":"2021-10-12T00:00:00Z","timestamp":1633996800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2022,2,17]]},"abstract":"<jats:title>Abstract<\/jats:title>\n               <jats:sec>\n                  <jats:title>Purpose<\/jats:title>\n                  <jats:p>In X-linked hypophosphatemia (XLH), excess fibroblast growth factor-23 causes hypophosphatemia and low calcitriol, leading to musculoskeletal disease with clinical consequences. XLH treatment options include conventional oral phosphate with active vitamin D, or monotherapy with burosumab, a monoclonal antibody approved to treat children and adults with XLH. We have previously reported outcomes up to 64 weeks, and here we report safety and efficacy follow-up results up to 160 weeks from an open-label, multicenter, randomized, dose-finding trial of burosumab for 5- to 12-year-old children with XLH.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Methods<\/jats:title>\n                  <jats:p>After 1 week of conventional therapy washout, patients were randomized 1:1 to burosumab every 2 weeks (Q2W) or every 4 weeks (Q4W) for 64 weeks, with dosing titrated based on fasting serum phosphorus levels between baseline and week 16. From week 66 to week 160, all patients received Q2W burosumab.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Results<\/jats:title>\n                  <jats:p>Twenty-six children were randomized initially into each Q2W and Q4W group and all completed treatment to week 160. In 41 children with open distal femoral and proximal tibial growth plates (from both treatment groups), total Rickets Severity Score significantly decreased by 0.9\u2005\u00b1\u20050.1 (least squares mean\u2005\u00b1\u2005SE; P\u2005&amp;lt;\u20050.0001) from baseline to week 160. Fasting serum phosphorus increases were sustained by burosumab therapy throughout the study, with an overall population mean (SD) of 3.35 (0.39) mg\/dL, within the pediatric normal range (3.2-6.1 mg\/dL) at week 160 (mean change from baseline P\u2005&amp;lt;\u20050.0001). Most adverse events were mild to moderate in severity.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Main conclusions<\/jats:title>\n                  <jats:p>In children with XLH, burosumab administration for 160 weeks improved phosphate homeostasis and rickets and was well-tolerated. Long-term safety was consistent with the reported safety profile of burosumab.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Clinicaltrials.gov<\/jats:title>\n                  <jats:p>NCT02163577<\/jats:p>\n               <\/jats:sec>","DOI":"10.1210\/clinem\/dgab729","type":"journal-article","created":{"date-parts":[[2021,10,17]],"date-time":"2021-10-17T21:34:27Z","timestamp":1634506467000},"page":"813-824","source":"Crossref","is-referenced-by-count":98,"title":["Sustained Efficacy and Safety of Burosumab, a Monoclonal Antibody to FGF23, in Children With X-Linked Hypophosphatemia"],"prefix":"10.1210","volume":"107","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-3455-002X","authenticated-orcid":false,"given":"Agn\u00e8s","family":"Linglart","sequence":"first","affiliation":[{"name":"AP-HP, Endocrinology and Diabetes for Children, Reference Center for Rare Disorders of the Calcium and Phosphate Metabolism, and Fili\u00e8re OSCAR, Bice\u0302tre Paris Saclay Hospital, Le Kremlin-Bic\u00eatre, France"},{"name":"Paris-Saclay University, INSERM 1189, Le Kremlin-Bic\u00eatre, France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7284-3467","authenticated-orcid":false,"given":"Erik A","family":"Imel","sequence":"additional","affiliation":[{"name":"Indiana University School of Medicine, Indianapolis, IN, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Michael P","family":"Whyte","sequence":"additional","affiliation":[{"name":"Shriners Hospitals for Children \u2013 St. Louis, MO, USA"},{"name":"Division of Bone and Mineral Diseases, Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Anthony A","family":"Portale","sequence":"additional","affiliation":[{"name":"University of California, San Francisco, CA, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Wolfgang","family":"H\u00f6gler","sequence":"additional","affiliation":[{"name":"Johannes Kepler University Linz, Linz, Austria"},{"name":"University of Birmingham, Birmingham, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Annemieke M","family":"Boot","sequence":"additional","affiliation":[{"name":"University Medical Center Groningen, University of Groningen, Groningen, the Netherlands"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Raja","family":"Padidela","sequence":"additional","affiliation":[{"name":"Royal Manchester Children\u2019s Hospital and Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"William","family":"van\u2019t Hoff","sequence":"additional","affiliation":[{"name":"Great Ormond Street Hospital, London, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gary S","family":"Gottesman","sequence":"additional","affiliation":[{"name":"Shriners Hospitals for Children - St. Louis, St Louis, MO, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Angel","family":"Chen","sequence":"additional","affiliation":[{"name":"Ultragenyx Pharmaceutical Inc., Novato, CA, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Alison","family":"Skrinar","sequence":"additional","affiliation":[{"name":"Ultragenyx Pharmaceutical Inc., Novato, CA, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mary","family":"Scott Roberts","sequence":"additional","affiliation":[{"name":"Ultragenyx Pharmaceutical Inc., Novato, CA, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1328-6768","authenticated-orcid":false,"given":"Thomas O","family":"Carpenter","sequence":"additional","affiliation":[{"name":"Yale 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