Endocrine Abstracts

JOINT1120

Background: Hypochondroplasia (HCH) is a disproportionate short statured skeletal dysplasia caused by gain-of-function pathogenic variants in the fibroblast growth factor receptor 3 gene (FGFR3) that lead to reduced endochondral bone growth. The natural history of HCH is not well characterized and longitudinal growth data for this condition are limited. Management of HCH is currently focused on treating specific complications.

Methods: ACCEL (NCT06410976) is a non-interventional clinical assessment study designed to characterize the natural history of children with HCH aged 2. 5 to < 17 years. The primary objective is to collect baseline height velocity measurements of children who may participate in an interventional study with infigratinib, an oral FGFR1–3 selective tyrosine kinase inhibitor in development for HCH. Secondary objectives are to collect other baseline growth measurements including height z-score and body proportion ratios, assess cognitive functions, evaluate HCH-related medical events and surgical procedures, and assess health-related quality of life. Evaluation of biomarker indicators of growth is an exploratory objective. Key inclusion criteria include diagnosis of HCH documented clinically by the presence of disproportionate short stature and confirmed with a molecular test. Participants will be assessed for a minimum of 6 months and a maximum of 2 years.

Results: The first participant enrolled in June 2024 and recruitment is ongoing in multiple countries.

Conclusion: Prospective data from this study will contribute to the characterization of the natural history of HCH and serve as a baseline for evaluation of infigratinib as a potential treatment option for children with HCH in future interventional studies.