Findings From Largest Single-Center Cohort in North America
Their topline findings revealed that patients with unifocal disease at diagnosis required 47% fewer total days of NSAID monotherapy treatment than those with multifocal disease at diagnosis, Dr. Nowicki told attendees. Having symmetric bone lesions increased the likelihood of needing a second-line therapy by 6.86 times compared with those without symmetric bone lesions, and for each additional region affected by CNO, the odds of needing a second-line therapy increased by a factor of 1.94, she said.
There were no significant differences in patient ages or sex or in mean interval from symptom onset to treatment onset across treatment groups. However, patients who received second-line treatment did have a significantly longer average time from symptom onset to diagnosis (324 days) than those who had a short course (119 days) or long course (270 days) of NSAIDs (P = .023). Mean follow-up was also significantly longer for patients with second-line treatment (3.8 years) or long-course NSAIDs (2.7 years) than for those with short-course NSAIDs (1.2 years; P < .001).
Mean erythrocyte sedimentation rate or C-reactive protein did not differ across treatment groups nor did presence of a CNO lesion on x-rays at presentation. But significantly more patients in the second-line group had a biopsy (94%) than in the long-course (74%) or short-course (69%) NSAID groups (P = .0025). They were also more likely to have one or more whole-body MRIs. Most of the patients on short-course (88%) and long-course (82%) NSAIDs did not undergo a whole-body MRI, whereas most patients (59%) on a second-line treatment underwent at least one and 24% underwent three or more MRIs (P < .001).
More patients on short-course NSAIDs had unifocal disease at diagnosis (72%) than those on long-course NSAIDs (47%) or a second-line treatment (41%; P = .015). Patients on a second-line treatment were also more likely to have symmetric involvement in the same bone (73% vs 16% short-course and 23% long-course NSAIDs) and to have more regions of the body affected (P < .001).
There were significant differences in mean days on NSAID monotherapy and number of NSAIDs trialed. Patients on a second-line treatment had a mean 441 days of NSAID monotherapy compared with 175 days for patients on short-course NSAIDs and 725 for patients on long-course NSAIDs (P < .001). Nearly all the short-course patients (94%) trialed a single NSAID, while more than half the long-course and second-line patients trialed two or more (P < .001).
None of the patients on short-course NSAIDs had complications. More patients on second-line treatments had vertebral height loss (20%) or amplified pain (14%) than long-course patients (13% and 5%, respectively; P = .02).
At the study’s end date, nearly all the patients on short-course NSAIDs were in remission (94%) compared with 71% of patients on long-course NSAIDs and only half of patients (51%) on the second-line treatment (P < .001). None of the patients on short-course NSAIDs had active disease compared with 11% of patients on long-course NSAIDs and 20% of patients on second-line treatments (P = .02).
This study included the largest single-center cohort of patients with CNO in North America, all treated at a multidisciplinary clinic with a protocolized treatment approach, but it remains limited by its retrospective nature and the missing data for 70 patients, Dr. Nowicki said. She noted that whole-body MRI was not systematically performed on all patients, so it was possible patients without a whole-body MRI had undetected asymptomatic lesions.
Despite these limitations, Dr. Oliver said retrospective studies like these can help pediatric rheumatologists get an idea of reasonable therapies to start, how long to keep patients on them, and when to escalate to the next step.
“I hope one day our CNO research will be able to tell us about which is the optimal second-line therapy for patients, such as bisphosphonates vs TNF inhibitors vs DMARDs [disease-modifying antirheumatic drugs],” Dr. Oliver said.
Dr. Nowicki and Dr. Oliver reported no disclosures. Information on study funding was not provided.
A version of this article appeared on Medscape.com .