Supplementary Material for: A Case of Secukinumab in the Treatment of Psoriasis-like Cutaneous Chronic Graft-versus-Host Disease

Chronic cutaneous graft - versus - host disease (cGVHD) represents a prevalent immune - mediated complication among patients with hematological malignancies following allogeneic hematopoietic stem cell transplantation (allo - HSCT). Clinically, it commonly presents with lichenoid and sclerotic cutaneous lesions. However, reports in the literature on psoriatic manifestations associated with cGVHD remain scarce. Moreover, the evidence base regarding the use of biologic agents in the management of cGVHD is limited. Herein, we present a case of psoriatic dermatitis in a patient with chronic cGVHD. The patient demonstrated a suboptimal response to conventional immunosuppressive therapies. Immunohistochemical analysis revealed positive expression of interleukin - 17 (IL - 17). Leveraging this finding, the patient was successfully treated with secukinumab, an anti - IL - 17A monoclonal antibody. After three months of treatment, the cutaneous lesions had substantially resolved, with no reported adverse effects. Thus, anti - IL - 17A monoclonal antibody therapy may represent an alternative treatment modality for cGVHD patients presenting with psoriatic phenotypes.