Efficacy and Safety Assessment of Upadacitinib for SAPHO Syndrome: A Retrospective Study of 35 Patients.

OBJECTIVE: This study aimed to evaluate the efficacy and safety of upadacitinib administered over a short-term period in patients with SAPHO syndrome. METHODS: In this 12-week retrospective observational study, eligible SAPHO syndrome patients diagnosed within the past year and treated with upadacitinib were enrolled. Efficacy was assessed using the Ankylosing Spondylitis Disease Activity Score based on C-reactive protein (ASDAS-CRP) and the Palmoplantar Pustulosis Area and Severity Index (PPPASI). Safety was evaluated based on the incidence of adverse events during the treatment period. RESULTS: A total of 35 eligible patients were included. Both ASDAS-CRP and PPPASI scores decreased rapidly by Week 4 (-1.01 and -11.41, respectively; both p < 0.001) and showed further significant improvements at Week 12 (-1.50 and -14.69, respectively; both p < 0.001) compared to baseline. Similar improvements were observed in the Visual Analogue Scale for overall musculoskeletal pain, the Bath Ankylosing Spondylitis Disease Activity Index, and other quality-of-life measures. Upadacitinib was well tolerated, with no serious adverse events reported. The most common adverse event was upper respiratory tract infection (20%). Other mild adverse events included elevated alanine aminotransferase, nausea, mild headache, and sore throat. CONCLUSION: Upadacitinib demonstrated a rapid onset of action, significant efficacy, and a favorable safety profile in the treatment of SAPHO syndrome, supporting its potential as a therapeutic option in clinical practice.