Biologics in SAPHO syndrome: A systematic review

The SAPHO syndrome is a relatively rare clinical entity characterized by a wide range of dermatological and musculoskeletal manifestations. Biologics have been used in cases refractory to conventional treatment.

We present herein a patient with refractory to treatment SAPHO syndrome who exhibited a dramatic and fast response to IL-17 blockade. Additionally, we performed a systematic review of all cases of patients with SAPHO syndrome treated with biologics to date.

We identified 66 cases treated with biologics (45 with TNF blockers, 7 with IL-1 blockers, 13 with biologics targeting the IL-23/IL-17 axis, and 1 with tocilizumab). Data support a positive effect of anti-TNF treatment in SAPHO with a response rate in bone and joint manifestations of 93.3%. Skin disease also improved in 21/29 cases (72.4%). Data related to IL-1 inhibition in SAPHO are encouraging with most patients exhibiting a significant response in musculoskeletal manifestations (6/7, 85.7%). However, IL-1 inhibition is not effective in skin manifestations. Ustekinumab seems to have some efficacy with 2/4 patients responding in skin and 3/5 in bone/joint manifestations. Data related to IL-17 blockade indicate efficacy in skin disease with 4/7 patients responding (57.1%). Joint/bone manifestations improved in 3/8 patients (37.5%).

In SAPHO patients not responding to conventional treatment, TNF blockers appear to be the first choice. In patients failing TNF blockers, IL-1 inhibitors and biologics targeting the IL-17/IL-23 axis could be used.