Bone Abstracts

Many disorders cause osteosclerosis, and many exclusively affect adults. Pediatricians are likely to encounter those that are Mendelian diseases, with most still classified as ‘dysplasias’ although now understood at the gene level. Thus, there is promise for defining their molecular and biochemical pathogeneses, and for developing targeted medical treatments. Sclerosing bone dysplasias too have become the ‘turf’ of the metabolic bone disease specialist. How...

Biographical DetailsMichael P Whyte is Professor of Medicine, Pediatrics, and Genetics at the Washington University School of Medicine, a staff member of Barnes-Jewish Hospital and St. Louis Children’s Hospital, and Medical-Scientific Director at the Center for Metabolic Bone Disease and Molecular Research, Shriners Hospital for Children in St. Louis, Missouri, USA.<p class="abst...

Objective: Children with hypophosphatasia (HPP) treated with asfotase alfa in a Phase 2 study (NCT00952484) and its open-label extension (NCT01203826) experienced significant improvements in skeletal mineralization and physical function that were sustained through 5 years of treatment (1). Herein, we report data from these studies with a maximum of 7 years of treatment.Methods: Children with HPP aged 6–12 years at baseline received asfotase alfa (3 ...

Objective: To evaluate safety and efficacy after 5 years of treatment with asfotase alfa in adolescents and adults with hypophosphatasia (HPP) in a Phase 2, open-label, randomized, dose-ranging study (NCT01163149).Methods: Treatment with subcutaneous asfotase alfa 0.3 or 0.5 mg/kg per d was compared with no treatment (control) for 6 months in patients aged 13–66 years. After 6 months, all patients (treatment and control groups) received active treat...

Objectives: Asfotase alfa (AA), an enzyme replacement therapy, is the only approved medical treatment for pediatric-onset hypophosphatasia (HPP), which is caused by deficient tissue-nonspecific alkaline phosphatase activity. We detail the long-term efficacy of AA observed from the pediatric clinical trial program.Methods: Efficacy data collected to study completion were pooled from 3 open-label, multicenter investigations of children who manifested HPP s...

Objectives: XLH features renal phosphate (Pi) wasting, hypophosphatemia, rickets, and skeletal deformities from elevated circulating levels of fibroblast growth factor 23 (FGF23). KRN23, an investigational fully human monoclonal antibody, binds FGF23 and inhibits its action. Our Phase 2 study of KRN23 in XLH children (ages 5–12 years) is demonstrating improvements in serum Pi and rickets. Here we present our Phase 2 trial evaluating the efficacy and safety of KRN23 in you...

Dysosteosclerosis (DSS) is the rare osteopetrosis (OPT) distinguished by metaphyseal osteosclerosis with relative radiolucency of widened diaphyses and platyspondyly. In 2012, mutations in the SLC29A3 gene were discovered to cause DSS.Here, we report a new case of DSS presenting with severe anemia and having a unique homozygous mutation in SLC29A3.Our patient was the 3rd child of consanguineous Turkish parents. She present...

Objectives: In XLH, musculoskeletal outcomes of current treatment with oral phosphate (Pi)/active vitamin D are suboptimal for many patients. In a Phase 2, open-label study, we tested the hypothesis that KRN23 improves rickets and functional outcomes in XLH children.Methods: Fifty-two children with XLH (ages 5–12 years at baseline) received KRN23 subcutaneously biweekly (Q2W) or monthly (Q4W). At study entry, most participants had received oral Pi/a...

Objectives: Asfotase alfa (AA), an enzyme replacement therapy, is the only approved treatment for pediatric-onset hypophosphatasia (HPP). We evaluated the safety profile of AA from the clinical trial program spanning pediatric and adult patients.Methods: Safety data were pooled from 4 open-label, multicenter studies in children aged ≤3 years (study 002/003 [NCT00744042/NCT01205152]; n=11) and ≤5 years (study 010-10 [NCT01176266]; <em...