Bone Abstracts

Objective: In 2018 we started treating children with X-linked hypophosphataemic rickets (XLH) with burosumab, initially as part of an industry-sponsored early access program. We present what we did, the barriers to implementation and broader lessons for the introduction of treatments for rare bone diseases in the future.

Method: Firstly, we identified suitable patients under the age of 18 years with XLH. For convenience we arranged dedicated clinics in which we were able to provide information and obtain consent efficiently. Within our institution, close liaison with and support from senior medical management and pharmacy were key elements that ensured we were able to proceed with the program in a timely fashion. Baseline assessment prior to first administration of the drug consisted of history and examination (including range of movement), fasted bloods, anthropometry, measurement of femoral and tibial torsion, plain radiographs of lower limbs, functional assessments (6 minute walk test (6MWT), ski sit, movement assessment battery for children) and quality of life assessment (PedsQL). Following commencement of burosumab, the same assessments were carried out 3 monthly in the same outpatient setting by the specialist team comprising a physician, clinical nurse specialist and physiotherapist.

Results: The response from patients regarding the clinics and the opportunity that they afforded for treatment was positive, colleagues in other centres provided indirect support and the data collected has provided useful regarding the impact of treatment on individuals and as part of a larger real-world cohort. However, the re-organisation of existing activity, increase in contacts and commitment to the collection and recording of more data was an increased burden of work. Practical and environmental difficulties risked failure of completion of data sets and threatened reliability e.g. availability of protected space to complete functional assessments such as the 6MWT.

Conclusion: The experience of implementing and monitoring burosumab has demonstrated the importance of working in a supportive and collaborative institutional and broader professional environment. However, if specialist teams are not properly resourced then there may be a risk that activity concerned with implementation of new drugs/technologies might occupy a disproportionate amount of time and/or be done without capturing key data.

Disclosure: Paul Arundel: Honoraria/expenses: Alexion and Kyowa Kirin. Expenses: BioMarin.