Real-world characteristics & disease history of patients with X-linked hypophosphatemia before treatment with burosumab

Summary

In a United States claims database, 1,358 persons with familial hypophosphatemia who began treatment with burosumab were identified. Prior to treatment, high rates of several morbidities were coded including osteoarthritis, fractures, enthesopathy, spinal stenosis, hypertension, depression and opioid use, which generally increased with age, emphasizing disease burden throughout the lifespan.

Purpose

To examine the characteristics and disease history of real-world patients with X-linked hypophosphatemia (XLH) in the United States, prior to initiating burosumab.

Methods

This retrospective cohort study used Komodo Health’s Healthcare Map™, a de-identified patient-level claims database. Included patients had ≥ 1 claim for familial hypophosphatemia between 01-Jan-2015 and 30-Jun-2022 (the study period) and ≥ 1 claim for burosumab between 01-Apr-2018 and 30-Jun-2022. The index date was the date of first burosumab claim. Patient demographics were measured at index; disease history was measured over the pre-index period and stratified by age. All variables were evaluated descriptively.

Results

1,358 patients were included (mean age 23.5 ± 19.1 years, 847 [62%] female); 720 patients (53%) were aged < 18 years. Prior to index, patients had high levels of XLH-related morbidities. Most XLH-related morbidities appeared in the youngest age groups, and the prevalence was generally greater among the older age groups. For example, arthralgia was found in 57 patients (12%) aged ≤ 11 years and 123 patients (69%) aged ≥ 50 years. Opioid use increased with age (173 patients [24%] aged < 18 years; 328 [51%] ≥ 18 years). Physical therapy use was observed across age groups (126 patients [18%] aged < 18 years; 253 [40%] ≥ 18 years).

Conclusions

At initiation of burosumab, over half of patients with XLH were < 18 years of age. Claims indicated a high prevalence of XLH-related morbidities, which began at a young age and increased over time.