ESPE Abstracts

Background: Hypophosphatasia (HPP) is a rare, inherited metabolic disease caused by loss-of-function mutations in the gene encoding tissue nonspecific alkaline phosphatase (TNSALP), resulting in hypomineralisation of bone. HPP presenting <6 months of age is often lethal due to respiratory insufficiency, with survival of 42% at 1 year. Asfotase alfa, a human recombinant TNSALP replacement, promotes bone mineralisation, with survival of 95% at 1 year in infants with HPP....

Background: Bone age (BA) is commonly used in pediatrics to define skeletal maturity for medical and non-medical purposes. Normal range is represented by 2 standard deviations (SDs) above and below the mean. A BA greater than &pm;2 SDs from the chronological age (CA) is considered abnormal. BA in achondroplasia (ACH) has not been fully characterized; calculation is challenging given difficulties in comparing x-rays with standard radiographs if using the Greuli...

Background: ACH, the most common short-limbed skeletal dysplasia, is characterized by defective endochondral ossification resulting from gain-of-function mutations in the fibroblast growth factor receptor 3 (FGFR3) gene, a negative regulator of endochondral bone formation. Current treatment options are non-targeted, ineffective, or painful interventions aimed at preventing or treating complications. Infigratinib is an orally bioavailable and selective...

Background: ACH is the most common short-limbed skeletal dysplasia, affecting between 1 in 15,000 to 1 in 30,000 live births. Children and adults with ACH have disproportionate short stature, with a final height of approx. 131 cm for males and 124 cm for females. People with ACH are prone to significant co-morbidities, including obstructive sleep apnea, chronic otitis media with conductive hearing loss, spinal stenosis, and a propensity towards obesity. In som...

Introduction: Vosoritide increases growth in children with achondroplasia aged 5–18 years (Savarirayan et al, Genet Med, 2021). We recently reported results from a phase 2, randomized, double-blind, placebo-controlled study (111-206) in young children with achondroplasia aged 3 months–5 years Here we present results from an open-label extension study (111-208) spanning up to 4 years of treatment in the children aged 2-5 years at study star...

Background: Achondroplasia (ACH), the most common short-limbed skeletal dysplasia, is characterized by impaired endochondral ossification resulting from gain-of-function pathogenic variants in the fibroblast growth factor receptor 3 (FGFR3) gene, a negative regulator of endochondral bone growth. People with ACH are at risk for several significant co-morbidities, including brainstem compression due to foramen magnum stenosis, sleep-disordered breathing, chronic...

Objectives: Achondroplasia (ACH) is characterized by disproportionate short stature and is associated with medical complications and functional constraints. Infigratinib is an oral FGFR3 inhibitor that targets overactive FGFR3 signaling at its origin and is under development as a treatment option for children with ACH. We report Month 18 results from PROPEL 2 (NCT04265651), a Phase 2, multicenter, open-label, dose-escalation and dose-expansion study to evaluat...