*6.2.2 Anti-IL-17*

The finding of increased blood levels of IL-17 in CSU patients was previously reported to be in association with CSU severity. This encouraged us to assess the status of IL-17 in the skin of CSU patients, thus, demonstrating increased IL-17 expression in CD4+ T cells and mast cells of both lesional and non-lesional skin of severe CSU patients. With this in mind, eight severe CSU patients (refractory to all approved therapies and steroid dependent) were treated with the anti-IL-17A antibody, secukinumab, demonstrating a significant improvement in CSU disease activity and were able to discontinue steroids. Future studies should be planned in order to expand this promising therapeutic approach [16, 96].

### **7. Summary**

The need for new treatments evolve from the fact that 15–20% of severe CSU patients will stay unresponsive to Omalizumab and are defined as being of un-met needs. Thus, a better understanding of the complexity of CSU pathogenesis led to the development of many new treatment options. In this chapter we reviewed the known and the ongoing clinical studies of the new treatments for severe CSU. We expect that some of these strategies will be efficient and will be added to the market of the existing therapies.

*Urticaria - Diagnosis and Management*
