Risankizumab Efficacy in Synovitis, Acne, Pustulosis, Hyperostosis, and Osteitis (SAPHO) Remission: A Case Report on Rheumatologic and Dermatologic Disease Manifestations with Literature Review.

SAPHO syndrome is a complex disease that encompasses both inflammatory arthritis and/or osteitis and dermatologic manifestations. It is considered a rare disease, in fact, no clinical trials have been conducted on its therapy and management. Therefore, therapeutic approach is based on small case studies. Here, we described the case of a 63-year-old woman affected by SAPHO syndrome, treated with the selective IL-23p19 antagonist, Risankizumab, after unsuccessful therapies with Methotrexate, Infliximab, Adalimumab, and an allergic reaction to Secukinumab. At the beginning of therapy, in November 2022, the patient presented with arthritis in both knees associated with palmar pustulosis and guttate psoriasis on the trunk. DAPSA score was 24, PtGA 80 mm, PASI score 11.1, and BSA 40%. Thereafter, Risankizumab was started at the standard dosage of 150 mg. At week 24 patient achieved clinical remission, DAPSA score was 8, PtGA was 30 mm, PASI was 1, and BSA 2.5. Patient maintained clinical remission state at the subsequent week 52 evaluation. At the same time, the patient did not report any adverse effects. Health-related quality of life was also assessed at the same time points aforementioned, showing significant improvement. In conclusion, this case report wants to point out the efficacy and safety of Risankizumab in SAPHO syndrome, reporting a sustained disease remission through a 12 months long follow-up period. We can consider IL-23p19 targeted therapy as a novel treatment option for SAPHO-with a high efficacy potential-especially on patients that have already been treated with other biologics.