P007 Oral Janus kinase inhibitor upadacitinib effective in refractory multisystem SAPHO syndrome with dissecting cellulitis

Background/Aims SAPHO (Synovitis, Acne, Pustulosis, Hyperostosis and Osteitis) syndrome is a rare autoinflammatory disorder characterised by osteoarticular and cutaneous manifestations, most commonly sternoclavicular joint pain, spondyloarthropathy and palmo-plantar pustulosis or acne. Although the syndrome is not life-threatening, it can have a significant impact on the quality of life of those affected. Treatment is indicated to manage symptoms and reduce risk of joint damage and varies based upon specific disease manifestations in individual patients. In refractory disease, there has been limited evidence for targeted inhibitors of Janus kinase (JAK). Oral JAK inhibitors tofacitinib and baricitinib have shown to be of benefit in several papers; however, upadacitinib in SAPHO syndrome has very limited real-world data. Methods We present a 29-year-old gentleman with left sternoclavicular, bilateral knee and left sacroiliac pain on a background of dissecting cellulitis with scalp lesions. MRI demonstrated bilateral patellar bone and femoral condyle marrow oedema representing osteitis. A nuclear medicine bone scan revealed increased metabolic activity within the patellar and femoral condyles bilaterally, with increased uptake in the first rib sternoclavicular joints. MRI confirmed inflammatory spondyloarthropathy with both axial features and sacroiliitis. Following a limited response to non-steroidal anti-inflammatory drugs he was offered methotrexate which he declined. Due to needle phobia limiting alternative biologic treatments he was commenced on upadacitinib 15mg daily. Results Pre-treatment BASDAI score was 4.9 which improved to 3.4 following 10 months of JAK inhibitor treatment with spinal visual analogue score improving from 8/10 to 2/10. CRP, ESR and exercise tolerance also improved post-treatment and there were no major adverse effects. In addition, intravenous pamidronate was used to treat persistent left knee pain secondary to osteitis with good response. Conclusion Upadacitinib was effective in treating refractory multisystem SAPHO syndrome in this case with concomitant axial spondyloarthritis, osteitis and dissecting cellulitis and should be considered as a treatment option in similar cases. Bisphosphonate therapy can be useful in treatment of bone pain secondary to osteitis. Disclosure Y. Suleman-Raza: None. Q. Amjad: None. P. Yee: None. R. Balaji: None.