Medications Used by Individuals with Fibrodysplasia Ossificans Progressiva (FOP): Data from a Global Natural History Study

Introduction FOP is an ultra-rare genetic disorder characterized by episodic progressive heterotopic ossification (HO) and flare-ups, causing cumulative disability and early death. There are no established disease-modifying therapies to prevent HO in FOP. However, treatment guidelines for the symptomatic relief of FOP have recently been published by the International Clinical Council on FOP (ICC).1 Objective: To report use of medications to manage symptoms of FOP in a natural history study (NHS), as per standard clinical practice.

Methods Individuals with FOP aged ≤65 years with a documented ACVR1R206H mutation were eligible to participate in a 36-month, prospective, global NHS (NCT02322255). This analysis reports interim data on medication use during the NHS (data cut 31 August 2019). Use of medications (acute and chronic) was assessed at Baseline (BL), by telephone at Weeks 1–3 and every 3 months thereafter, and at clinic visits (Months 12, 24, and 36). Medication prescribed for symptomatic treatment of reported flare-ups was recorded on flare-up Days 1, 42, and 84. Data were collected using a standardized list and are summarized here by preferred term (PT).

Results 73/114 (64.0 %) participants were taking prior medications that were ongoing at BL in the NHS. The most common medications ongoing at BL by PT were prednisone (25.4 %), ibuprofen (22.8 %), and montelukast (19.3 %), all of which are included in the ICC guidelines. Pain relief medications ongoing at BL also included (among others): paracetamol (11.4 %), naproxen (8.8 %), and celecoxib (7.9 %). Most participants (91/114; 79.8 %) initiated treatment with new medications during the NHS. The most frequent newly-initiated medications by PT were prednisone (31.6 %), ibuprofen (28.1 %), and paracetamol (21.9 %). Glucocorticoids were commonly administered upon onset of flare-ups (155/217; 71.4 %), in accordance with ICC guidelines.

Discussion To manage their symptoms during this NHS, individuals with FOP used various medications, which were generally consistent with current ICC guidelines. Although the objective of this study was not to evaluate efficacy or safety of medications used, it highlights the need for disease-modifying therapies to treat or prevent the symptomatic progression of FOP. Reference: 1. Kaplan FS. ICC FOP Treatment Guidelines. Available at: http://www.iccfop.org/dvlp/wp-content/uploads/2020/03/Guidelines_January-2020.pdf [Accessed: 14 May 2020].

Keywords FOP, NHS, rare bone disease

Korrespondenzadresse Richard Keen, Royal National Orthopaedic Hospital, Stanmore, UK, Centre for Metabolic Bone Disease, Brockley Hill, 74 Stanmore, UK

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Conflict of interest Research investigator: Clementia/Ipsen, Kyowa Kirin, Regeneron; Advisory board: IFOPA FOP Registry Medical Advisory Board, International Clinical Council on FOP