A Prospective, Interventional, Exploratory Study Evaluating the Efficacy of Small-Molecule Compound XJH05 Ointment in the Treatment of Plaque Psoriasis

Psoriasis is a chronic, recurrent, inflammatory, and systemic disease mediated by immunity, induced by a combination of genetic and environmental factors. Its typical clinical manifestations are scaly erythema or plaques, which may be localized or widespread. It is non-contagious, difficult to treat, and often lifelong. The etiology of psoriasis involves multiple factors, including genetics, immunity, and environment. Through an immune response primarily mediated by T lymphocytes and jointly participated in by various immune cells, it causes hyperproliferation of keratinocytes or inflammation in joint synovial cells and chondrocytes. Psoriasis is an incurable disease; however, numerous therapeutic drugs and methods are currently available. Treatment regimens should be determined based on patient symptoms: mild psoriasis is mainly treated with topical therapies, while moderate-to-severe cases can be managed with systemic therapies. Targeted biologics may be appropriately selected for patients who show an inadequate response to traditional systemic therapies. The goals of psoriasis treatment focus on controlling symptoms and improving patients' quality of life. Psoriasis is classified into different subtypes, among which plaque psoriasis is the most common subtype (accounting for approximately 90%). Among these, about 80% of psoriasis patients have mild disease, with topical drug therapy being the preferred first-line treatment. Currently, commonly used topical agents include vitamin D3 derivatives, glucocorticoids, retinoids, and topical combination preparations.

Recent studies have revealed that the interaction between lipocalin-2 (LCN2) and its receptor SLC22A17 plays a key role in the pathogenesis and progression of psoriasis: the LCN2/SLC22A17 axis induces abnormal cholesterol metabolism in keratinocytes by activating the SREBP2 pathway, and acts synergistically with the NLRC4 inflammasome to trigger the release of inflammatory mediators such as IL-1$\beta$ and IL-18. This chemoselectively recruits and activates neutrophils, establishing a continuously amplified inflammatory cascade. Notably, direct inhibitors or antagonists targeting the SLC22A17 receptor have not been fully developed in existing technologies, and reports regarding the molecular structures, selectivity, and druggability of relevant compounds remain rare. Most studies are still confined to preliminary exploration via genetic intervention or antibody blockade, lacking molecular entities that can be translated into clinical applications. By screening and validating the potential of the specific small-molecule compound XJH05 to achieve upstream intervention in psoriasis by targeting SLC22A17, we aim to provide a therapeutic solution for psoriasis that possesses both mechanistic innovation and clinical feasibility. This small-molecule drug can specifically bind to the active site of the SLC22A17 protein, blocking the interaction between SLC22A17 and LCN2. Consequently, it inhibits the activation of the LCN2-SREBP2-NLRC4 signaling axis and downregulates the expression of pro-inflammatory cytokines, thereby blocking at the molecular level both the pathological hyperproliferation of epidermal keratinocytes and the infiltration of immune cells such as neutrophils, which are characteristic features of psoriasis.

Although numerous drugs and therapeutic methods are currently available for psoriasis, it remains an incurable disease. Through animal experiments and in vitro drug interventions on psoriasis patient skin lesions, we have demonstrated that the small-molecule drug XJH05 is safe, effective, and free of adverse reactions; however, clinical data regarding XJH05 ointment in the treatment of patients with plaque psoriasis are still lacking. Therefore, we plan to conduct a prospective, interventional, exploratory study on the efficacy of XJH05 ointment in treating plaque psoriasis, hoping to provide further evidence regarding the therapeutic efficacy of XJH05 ointment in the psoriasis patient population.