Improvement in the mobility of a patient with fibroblast growth factor 23-related hypophosphatemic osteomalacia and decompensated liver cirrhosis in response to burosumab: a case report

• DOI: 10.1507/endocrj.ej22-0520
• Publication Date: 2022-12-27T22:10:02Z
• Authors: Norikazu Toi; Yasuo Imanishi; Yuki Nagata; Masafumi Kurajoh; Tomoaki Morioka; Tetsuo Shoji; Yoshitaka Shinto; Masanori Emoto
• Keywords: Hypophosphatemia; Osteomalacia; Bone pain; Liver function

Acquired fibroblast growth factor (FGF) 23-related hypophosphatemic osteomalacia is characterized clinically by muscle weakness, bone pain, and fractures. Its biochemical features include hypophosphatemia, caused renal phosphate wasting, inappropriately normal or low 1,25-dihydroxy-vitamin D levels. Recently, burosumab, a fully human monoclonal antibody targeting FGF23, was approved for the treatment of FGF23-related rickets osteomalacia. We report case 75-year-old Japanese woman with decompensated liver cirrhosis hepatic encephalopathy, primary biliary cholangitis, who complained back pain limited mobility resulting from multiple vertebral She not receiving iron infusion therapy denied alcohol consumption. The patient exhibited hypophosphatemia tubular maximum reabsorption per unit glomerular filtration rate (TmP/GFR) high circulating concentration FGF23. Conventional alfacalcidol oral slightly improved her serum but she experienced hip fracture, causing to become wheelchair-dependent. Burosumab initiated 8 weeks after which increased TmP/GFR. Her gradually improved, such that could walk without cane 16 treatment. lumbar mineral density 48 weeks. Hepatic encephalopathy developed once before initiation twice therapy, function preserved. This first study efficacy safety burosumab cirrhosis.