JAK Inhibitors for Treatment of SAPHO Syndrome: A Systematic Review of 72 Cases

Synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome usually involves bones, joints, and skin. Due to a lack of known pathogenesis and clinical trials, there is no standard treatment of SAPHO syndrome. Because none of the current treatments have a high efficacy and the risk of relapse is high, new treatment options for SAPHO syndrome are necessary. JAK inhibitors (JAK-I) are a group of small-molecule drugs with a wide range of effects on inflammatory and autoimmune pathways.

A systematic search was conducted using medical subject headings terms or keywords related to JAK-I and SAPHO syndrome through PubMed/Medline, Scopus, Web of Science, and Embase until September 8, 2024. The inclusion criteria included a patient diagnosed with SAPHO syndrome who received at least one JAK-I. We excluded reviews and animal studies.

Of 287 initially researched articles, we included 34 articles. These 34 articles represent 72 patients with a mean age of 39.36 years. Of these, 56 (78%) were female. All patients had bone or joint involvement, and 64 patients had skin involvement. Seventy patients (97.2%) had received at least one treatment before using JAK-I. All patients received just one JAK-I. Of these, 54 (75%) received tofacitinib, 15 (20.8%) received baricitinib, and 3 (4.2%) received upadacitinib. All patients except one (98.6%) showed good to complete response. Ten patients (13.9%) showed a clinical adverse effect. All were taking tofacitinib, with adverse effects leading to drug discontinuation in just one of these patients.

JAK-I seems to be a promising treatment of SAPHO syndrome, with manageable adverse effects.