18A133

Beyond NSAIDS : second-line therapeutic agents for chronic recurrent multifocal osteomyelitis

Author(s)

O Leary DM, Mac Dermott EJ, Wilson AG, Killeen OG

Department(s)/Institutions

National Centre for Paediatric Rheumatology, Our Lady's Children's Hospital School of Medicine, University College Dublin National Children's Research Centre, Dublin

Introduction

Chronic recurrent multifocal osteomyelitis (CRMO) is a rare autoinflammatory disease affecting bone. Untreated CRMO can result in complications such as vertebral compression fractures and leg length discrepancy. First line treatment is with non-steroidal anti-inflammatory drugs (NSAIDs) with a reported response rate of 50-80%. Limited data is available on the efficacy of second-line treatments which include methotrexate, bisphosphonates and biologic agents.

Aims/Background

To describe the experience of the National Centre for Paediatric Rheumatology (NCPR) treating currently attending CRMO patients with second-line agents.

Method

Retrospective chart review of current patients requiring second-line agents attending the National Centre for Paediatric Rheumatology. Persistent active disease was defined as persistent pain with tenderness/warmth or persistent bone oedema on MRI in at least one lesion site after >4 weeks treatment (CARRA consensus treatment guidelines). Response to treatment was defined as clinical and/or radiological improvement without complete resolution. Remission was defined as normal ESR, absence of clinically active lesions, resolution of marrow oedema on MRI and absence of new lesions on whole-body MRI (modified CARRA criteria for treatment failure).

Results

Clinical charts of 30 patients with CRMO were reviewed. Second-line treatment was required in 60%. The indications for second-line treatment were persistent active disease on NSAIDS or the presence of spinal lesions or cosmetically significant mandibular lesion.
A total of 19 patients received methotrexate, either alone (n=8 )or in combination with a biologic agent (n=11). Three received pamidronate; none achieved remission and all subsequently received methotrexate +/- biologic. Of those who received methotrexate monotherapy, 1 is in remission on treatment, 1 remains in remission off treatment, 6 have responded but not achieved remission.
Of those on biologic combination therapy, 2 patients are in remission, 1 discontinued treatment due to a hypersensitivity reaction. The remaining patients improved but have yet to achieve remission.

Conclusions

Treatment with second-line agents has led to a symptomatic improvement in all patients.
Combination therapy of methotrexate and a biologic agent may be the most favourable option but randomised controlled trials with clearly defined response and remission criteria are required.