Study data results published in Pediatric Rheumatology support the efficacy and tolerability of pamidronate for chronic nonbacterial osteitis (CNO) in children.

Investigators conducted a retrospective medical record review of children diagnosed with CNO between 2005 and 2018 at a tertiary health center in the United Kingdom. Children with disease onset before the age of 16 years who received bisphosphonates were included in the study. Pre and posttreatment whole-body magnetic resonance imaging (WB-MRI) data were extracted; treatment response was ascertained based on WB-MRI lesion status. Patient exposure to nonsteroidal anti-inflammatory drugs (NSAIDs), methotrexate, and corticosteroids was also extracted.

The final study cohort comprised 46 patients with a mean follow-up duration of 6 years (range, 1-13 years). Prior to treatment with pamidronate, 35 patients had a trial of NSAIDs, 4 received corticosteroids, and 5 had a trial of methotrexate. Patients with poor clinical or radiologic response to initial treatment were escalated to pamidronate. However, bisphosphonates were used as first-line treatment in 9 patients (19.5%) with spinal lesions and 2 patients (4.3%) with mandibular disease. Patients (n=40) with posttreatment WB-MRI data had a total lesion count of 150; this value was reduced to 45 (30%) following treatment with pamidronate. A total of 17 patients (42.5%) had complete resolution of all lesions, constituting good response; 10 (25%) and 4 (10%) patients had a moderate and mild response, respectively; 9 patients (22.5%) had no response. Patients (n=9) with vertebral disease at first CNO presentation also achieved good pamidronate response, with 82.3% of vertebral lesions (14 of 17 lesions) resolving completely. Treatment was escalated to anti-tumor necrosis factor (TNF) agents in patients with suboptimal bisphosphonate response. Pamidronate was relatively well-tolerated by patients, with just 2 of the 46 patients discontinuing treatment due to infusion-related side effects.

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These data support treatment with pamidronate following suboptimal response to NSAIDs, although bisphosphonates were also effective as first-line treatment in the presence of spinal or mandibular lesions. WB-MRI was also confirmed as an effective marker of disease activity in CNO. Research in a prospective cohort is necessary to confirm the efficacy of pamidronate and to compare pamidronate with anti-TNF agents in the treatment of CNO.

Reference

Bhat CS, Roderick M, Sen ES, Finn A, Ramanan AV. Efficacy of pamidronate in children with chronic non-bacterial osteitis using whole body MRI as a marker of disease activity. Pediatr Rheumatol Online J. 2019;17:35.