Addressing the urgent need for clinical trials in chronic non-bacterial osteomyelitis

Chronic non-bacterial osteomyelitis (CNO) is an autoinflammatory bone disease primarily affecting children and adolescents. The condition is characterised by bone pain, hyperostosis, and bone deformities, impacting patients' quality of life. Although CNO is the second most common inflammatory rheumatic disease in childhood, no licensed treatments exist. Clinical trials have been challenged by the absence of validated classification criteria and inclusion and exclusion criteria, a shortage of well-validated tools to measure treatment response, and a small market for commercialisation. Clinical trials are urgently needed to generate evidence and allow licensing of medications. Since 2022, long-standing challenges, previously hindering trial design and delivery in CNO, have been addressed through the development of classification criteria, expert consensus on inclusion and exclusion criteria, and the development of outcome measures. Applying a platform trial design testing treatments against a common comparator promises to deliver several key benefits for patients with CNO, families, and health-care services. This Viewpoint summarises treatments currently used to treat CNO alongside promising future candidates, outlining challenges in trial design and how these have, partly, been overcome.