ESPE Abstracts

Background: Achondroplasia (ACH) is a rare genetic condition caused by a gain-of-function variant in the fibroblast growth factor receptor 3 (FGFR3) gene. It results in severe disproportionate short stature and medical complications requiring multidisciplinary care. Vosoritide, a C-type natriuretic peptide analogue, is currently the only approved targeted treatment for children with ACH from birth to epiphyseal closure. Understanding real-world ACH management and treatment outcomes is important. Electronic health records (EHR) in the USA as a data source are limited for ACH due to non-specific ICD-10 coding and the fragmented care model. VISTA (NCT06168201) aims to use a patient-centred, virtual, decentralised approach to comprehensively collect data from untreated and vosoritide-treated individuals with ACH to monitor real-world effectiveness of vosoritide. A pilot phase was initiated to evaluate study feasibility and data availability quality.

Methods: Individuals with ACH (<18 years) were recruited using the PicnicHealth digital aggregation platform, which enables EHR collation from multiple healthcare providers and systems, both retrospectively and prospectively. At enrolment and 6-monthly intervals, physical functioning and health-related quality of life (HRQoL) were assessed using the PROMIS lower extremity (mobility) and upper extremity tools, and PedsQL. Participants also completed medication adherence and clinical trial participation questionnaires. Customised abstraction from structured and unstructured EHR text was performed to obtain a de-identified dataset of relevant clinical data.

Results: Within the pilot from February 2023 to January 2024, 20 individuals with ACH (50% males, median age 4.2 years) were enrolled; 55% received vosoritide. All domains of interest, including comorbidities, surgeries, and anthropometric measures, had available data; the median rate of standing height measurements was 6 measures/year. Medication adherence and clinical trial questionnaires were completed by 90% of participants; PROMIS by 67% of parents and 100% of eligible children; and PedsQL by 69% of parents and 33% of eligible children. The median number of healthcare providers was 22 from 8 sites of care per participant (median 4.3 years). The median number of visits/year was 5.8; most common specialist visits were geneticists (95%), paediatric orthopaedists (90%), and otolaryngologists (75%). Among vosoritide-treated individuals, 82% reported no missed injections in the previous month.

Conclusion: The pilot phase confirmed feasibility of the data collection model, yielding high-quality comprehensive data. As the study expands and enrolment increases, outcomes like HRQoL, surgeries, and comorbidities will be presented. Vosoritide adherence was high. The healthcare resource utilisation journey for ACH is complex and variable, requiring multidisciplinary care for effective management.