IL-17 Signaling Inhibitors in Localized Scleroderma: A Single-Center Case Series of Nine Patients.

Localized scleroderma (LSc) is an autoimmune fibrosing disorder characterized by inflammation and sclerosis of the skin and underlying soft tissues. IL-17 signaling has been implicated in active inflammatory lesions, but treatment options for severe or refractory LSc remain limited. Here, we present nine patients with LSc treated with IL-17A or IL-17 receptor A inhibitors at our institution (ixekizumab, secukinumab, or brodalumab). These biologics were administered to patients refractory to conventional therapies or anticipated to have treatment-resistant disease, following institutional approval for unapproved drug use. Five patients improved, two stabilized, and two progressed. One patient developed pustulotic arthro-osteitis during brodalumab treatment, possibly representing a paradoxical reaction; no other major adverse events were observed. Although these uncontrolled retrospective data do not establish efficacy, they suggest that IL-17 pathway inhibition merits further study in selected patients with refractory LSc.