hrp0086s1.1 | Innovative therapies in bone and mineral metabolism | ESPE2016

Innovative Therapies in Bone and Mineral Metabolism: Anti FGF23 in X-linked Hypophosphatemia

Carpenter Thomas

Background: Hypophosphatemia due to excess urinary phosphate losses and rachitic bone disease occur in several related disorders. The most common form of the heritable hypophosphatemic disorders, X-linked hypophosphatemia (XLH), is due to loss-of-function mutations of the osteocyte/osteoblast protein, PHEX. Reduced abundance of phosphate transporters on the luminal surface of renal tubular cells in the syngeneic animal model of XLH, and inappropriately normal (or frankly low) ...

hrp0086wg4.5 | ESPE Bone and Growth Plate Working Group (BGP) | ESPE2016

FGF23, Klotho and PTH in the Regulation of Mineral Homeostasis

Carpenter Thomas

Background: The Fibroblast Growth Factors (FGFs) are a large family of proteins including paracrine, intracrine, and endocrine FGFs. Paracrine and endocrine FGFs interact with specific cell surface receptors (FGFRs) that, via intracellular tyrosine kinase activity, initiate a cascade of downstream intracellular events. Specificity of paracrine/autocrine FGF activity is provided locally by the local production of these FGFs and their cognate receptors. In contrast, endocrine FG...

hrp0084p1-20 | Bone | ESPE2015

24-Hydroxylase Polymorphism as a Possible Contributor to the Increased 1,25(OH)2D in African Americans

Carpenter Thomas O , Cole David E C , Ardeshirpour Laleh , Salehpour Shadab

Background: States of vitamin D insufficiency are important determinants of rickets, as well as osteoporosis and other common complex disorders like diabetes, cancer, and infectious diseases. Although, serum concentrations of the vitamin D metabolites are primarily driven by vitamin D supply (by diet or cutaneous synthesis), there is emerging evidence to suggest that single nucleotide variants (SNVs) are important genetic determinants.Objective and hypot...

hrp0089fc2.1 | Bone, Growth Plate & Mineral Metabolism 1 | ESPE2018

Burosumab, a Fully Human anti-FGF23 Monoclonal Antibody, for X-linked Hypophosphatemia (XLH): Sustained Improvement in two Phase 2 Trials in Affected Children 1–12 years old

Linglart Agnes , van't Hoff William , Whyte Michael P. , Imel Erik , Portale Anthony A. , Boot Annemieke , Hogler Wolfgang , Padidela Raja , Mao Meng , Skrinar Alison , Martin Javier San , Carpenter Thomas O.

In XLH, excess fibroblast growth factor 23 (FGF23) causes hypophosphatemia and consequent rickets, skeletal deformities, and growth impairment. The efficacy and safety of burosumab, a fully human monoclonal antibody against FGF23, was evaluated in two Phase 2 trials in children with XLH. In CL201, 52 children with XLH (5–12 years old, Tanner ≤2) were randomized 1:1 to receive subcutaneous burosumab every 2 (Q2W) or 4 (Q4W) weeks, with doses titrated up to 2 mg/kg to...

hrp0082fc2.5 | Bone & Mineral | ESPE2014

Pharmacokinetics and Pharmacodynamics of a Human Monoclonal Anti-Fibroblast Growth Factor 23 Antibody (KRN23) Following 4 Month Intra-Dose Escalation in Adults with X-Linked Hypophosphatemia

Zhang Xiaoping , Imel Erik , Ruppe Mary , Weber Thomas , Klausner Mark , Ito Takahiro , Vergeire Maria , Humphrey Jeffrey , Glorieux Francis , Portale Anthony , Insogna Karl , Peacock Munro , Carpenter Thomas

Background: In X-linked hypophosphatemia (XLH), abnormally elevated serum fibroblast growth factor 23 (FGF23) results in low renal maximum threshold for phosphate reabsorption (TmP/GFR), low serum phosphorus (Pi), inappropriately normal 1,25-dihydroxyvitamin D (1,25(OH)2D) and development of rachitic deformities.Methods: Up to four s.c. KRN23 doses were given every 28 days to 28 adults with XLH according to a dose-escalation algorithm (0.05&#1...

hrp0082fc2.6 | Bone & Mineral | ESPE2014

Efficacy and Safety Following 4 Monthly s.c. Doses of a Human Anti-Fibroblast Growth Factor 23 Antibody (KRN23) in Adults with X-linked Hypophosphatemia

Peacock Munro , Imel Erik , Zhang Xiaoping , Ruppe Mary , Weber Thomas , Klausner Mark , Ito Takahiro , Vergeire Maria , Humphrey Jeffrey , Glorieux Francis , Portale Anthony , Insogna Karl , Carpenter Thomas

Background: In X-linked Hypophosphatemia (XLH), abnormally elevated serum Fibroblast Growth Factor 23 (FGF23) results in low renal maximum threshold for phosphate reabsorption (TmP/GFR), low serum phosphorus (Pi), inappropriately normal 1,25-dihydroxyvitamin D (1,25(OH)2D) and development of rachitic deformities.Methods: Up to four SC KRN23 doses were given every 28 days to 28 adults with XLH (26 completed) according to a dose-escalation algorithm (0.05&...

hrp0082p1-d2-35 | Bone | ESPE2014

Assessment of Quality of Life Data After 4 Monthly S.C. Doses of a Human Monoclonal Anti-Fibroblast Growth Factor 23 Antibody (KRN23) in Adults with X-linked Hypophosphatemia

Ruppe Mary , Zhang Xiaoping , Imel Erik , Weber Thomas , Klausner Mark , Ito Takahiro , Vergeire Maria , Humphrey Jeffrey , Glorieux Francis , Portale Anthony , Insogna Karl , Peacock Munro , Carpenter Thomas

Objectives: In X-linked hypophosphatemia (XLH), abnormally elevated serum Fibroblast growth Factor 23 (FGF23) results in low renal maximum threshold for phosphate reabsorption, low serum phosphorus, inappropriately normal 1,25-dihydroxyvitamin D, and development of rachitic deformities. The effect of KRN23 on health-related quality of life (HRQL) was assessed.Methods: Open-label KRN23 was given s.c. every 28 days up to four doses to 28 adults with XLH (2...

hrp0092fc2.1 | Bone, Growth Plate and Mineral Metabolism Session 1 | ESPE2019

Continued Improvement in Clinical Outcomes with Burosumab, a Fully Human Anti-FGF23 Monoclonal Antibody: Results from a 3-Year, Phase 2, Clinical Trial in Children with X-Linked Hypophosphatemia (XLH)

Linglart Agnès , Carpenter Thomas O. , Högler Wolfgang , Imel Erik A. , Portale Anthony A. , Boot Annemieke , Padidela Raja , Van't Hoff William , Mao Meng , Skrinar Alison , Scott Roberts Mary , San Martin Javier , Whyte Michael P.

In children with XLH, excess FGF23 causes hypophosphatemia with consequent rickets, skeletal deformities, and impaired growth and mobility. We previously reported that burosumab improved phosphate homeostasis and rickets in children with XLH. Here, we report final data from this Phase 2 Study CL201 (NCT02163577).Fifty-two children with XLH (5-12 years old, Tanner ≤ 2) were randomized 1:1 to receive subcutaneous burosumab every 2 (Q2W) or 4 (Q4W) we...

hrp0092fc2.2 | Bone, Growth Plate and Mineral Metabolism Session 1 | ESPE2019

Benefits of Long-Term Burosumab Persist in 11 Girls with X-Linked Hypophosphatemia (XLH) Who Transitioned into Adolescence During the Phase 2 CL201 Trial

Boot Annemieke , Carpenter Thomas O. , Högler Wolfgang , Imel Erik A. , Portale Anthony A. , Linglart Agnès , Padidela Raja , Van't Hoff William , Mao Meng , Skrinar Alison , Scott Roberts Mary , San Martin Javier , Whyte Michael P.

In children with XLH, excess FGF23 causes hypophosphatemia with consequent rickets, skeletal deformities, and impaired growth and mobility. We reported that burosumab improved phosphate homeostasis and rickets in children with XLH. Here, we present data on 11/52 subjects (all girls) who developed fused growth plates during the phase 2 study CL201 (NCT02163577).In CL201, 52 subjects (Baseline: 5-12 years-old, Tanner ≤ 2) were randomized 1:1 to recei...

hrp0086fc2.6 | Bone & Mineral Metabolism | ESPE2016

Effect of KRN23, a Fully Human Anti-FGF23 Monoclonal Antibody, on Rickets in Children with X-linked Hypophosphatemia (XLH): 40-week Interim Results from a Randomized, Open-label Phase 2 Study

Linglart Agnes , Carpenter Thomas , Imel Erik , Boot Annemieke , Hogler Wolfgang , Padidela Raja , van't Hoff William , Whyte Michael , Chen Chao-Yin , Skrinar Alison , Agarwal Sunil , Martin Javier San , Portale Anthony

Background: In XLH, high circulating FGF23 causes hypophosphatemia, rickets, and short stature.Objective and hypotheses: To evaluate KRN23 effects on serum phosphate (Pi) level and rickets severity in XLH children in a Phase 2 study.Method: 52 XLH children (ages 5–12 years, ≤Tanner 2) received KRN23 subcutaneously biweekly (Q2W) or monthly (Q4W). Serum Pi was measured at 2-week intervals. KRN23 dose was titrated (maximum...