Project description:Risankizumab, a humanized monoclonal antibody that targets interleukin-23 p19 subunit, was developed for the treatment of psoriasis. This work characterizes risankizumab pharmacokinetics in Japanese and Chinese healthy subjects compared with white healthy subjects and in Japanese patients with moderate to severe plaque psoriasis, generalized pustular psoriasis, or erythrodermic psoriasis. A phase 1, single-dose study evaluated risankizumab pharmacokinetics and safety/tolerability in healthy white (18 and 300 mg subcutaneous [SC]), Japanese (18, 90, and 300 mg SC and 200, 600, and 1200 mg intravenous [IV]), and Chinese (18, 90, and 300 mg SC) subjects; pharmacokinetic data were analyzed using noncompartmental methods. Risankizumab pharmacokinetic data from phase 2/3 studies in Japanese patients with plaque psoriasis, generalized pustular psoriasis, or erythrodermic psoriasis following multiple SC doses of 75 mg or 150 mg were analyzed using a population pharmacokinetic approach along with data from the phase 1 and global phase 1 to 3 studies. Risankizumab plasma exposures (peak plasma concentration and area under the concentration-time curve) were approximately dose-proportional across 18- to 300-mg SC or 200- to 1200-mg IV doses. Risankizumab terminal elimination half-life (harmonic mean 27-34 days) was comparable across doses and ethnicities. Risankizumab exposures were approximately 20% to 30% higher in Japanese and Chinese healthy subjects compared with white healthy subjects or in Japanese patients compared with non-Japanese patients. After accounting for body-weight differences, risankizumab exposures were comparable across ethnicities. Overall, there was no ethnic impact on risankizumab pharmacokinetics, and the small difference in exposure due to body weight has no clinical relevance.
Project description:Generalized pustular psoriasis (GPP) is a rare, debilitating, and often life-threatening inflammatory disease characterized by episodic infiltration of neutrophils into the skin, pustule development, and systemic inflammation, which can manifest in the presence or absence of chronic plaque psoriasis (PV). Current treatments are unsatisfactory thus a better understanding the pathogenesis of GPP is warranted. To assess the pathophysiological differences between GPP and PV we performed a gene expression study on formalin-fixed paraffin-embedded biopsies of GPP (n=30) and PV (n=12) lesions and healthy control (n=20) skin. Compared with healthy skin, GPP lesions yielded 365 and PV 898 differentially expressed genes respectively, with 190 upregulated in both diseases. We detected higher expression of IL-1 and IL-36 cytokines in GPP lesions compared with PV, and this occurred proximal to neutrophils. We show both activated neutrophils and isolated neutrophil proteases can activate IL-36. Diverging from the Th1/Th17 pathophysiology of PV, significantly fewer IL23A, IL17A, IFNG, CXCL9, CXCL10 and MX1 transcripts were detected in GPP lesions. Our data indicate a level of sustained activation of IL-1 and IL-36 in GPP, inducing neutrophil chemokine expression, infiltration and pustule formation, suggesting that the IL-1 and IL-36 inflammatory axes are the main drivers of disease pathology in GPP.
Project description:Epigenetics plays a role in the pathogenesis of psoriasis vulgaris and generalized pustular psoriasis (GPP) through DNA methylation modifications that cause changes in immune responses. Psoriasis vulgaris is dominated by autoimmune responses, driven by Th17 cells producing IL-17, whereas GPP is dominated by autoinflammatory responses resulting from IL-36 dysregulation and neutrophil hyperactivation. Objective: This study aims to determine the DNA methylation profile and analyze the differences in IL-17 and IL-36 levels in both psoriasis phenotypes and healthy controls. Method: This study employed a cross-sectional design, comprising 20 patients with psoriasis vulgaris, three patients with GPP, and 13 healthy controls. DNA methylation profiles were assessed using Reduced Representation Methylation Sequencing, while IL-17 and IL-36 levels were assessed using ELISA. Results: Increased 5-methyl cytosine (5mC) was identified in psoriasis vulgaris and GPP compared to healthy controls. Increased 5mC at the FOXP3 promoter was identified in GPP and psoriasis vulgaris with high IL-17 levels, while decreased 5mC at the CARD14 promoter was identified in psoriasis vulgaris with high IL-17 levels. GPP showed higher IL-17 levels than healthy controls (p<0.05). IL-17 levels in psoriasis vulgaris showed no significant difference compared to GPP and healthy controls (p>0.05). IL-36 levels did not differ significantly among the three groups, with the highest IL-36 levels observed in psoriasis vulgaris (p>0.05). Conclusion: Increased DNA methylation in the FOXP3 gene promoter is predicted to cause high IL- 17 levels in psoriasis vulgaris and GPP, while IL-36 levels are higher only in psoriasis vulgaris.
Project description:Psoriasis is a chronic inflammatory skin condition that has a fairly wide range of clinical presentations. Plaque psoriasis, which is the most common manifestation of psoriasis, is located on one end of the spectrum, dominated by adaptive immune responses, whereas the rarer pustular psoriasis lies on the opposite end, dominated by innate and autoinflammatory immune responses. In recent years, genetic studies have identified six genetic variants that predispose to pustular psoriasis, and these have highlighted the role of IL-36 cytokines as central to pustular psoriasis pathogenesis. In this review, we discuss the presentation and clinical subtypes of pustular psoriasis, contribution of genetic predisposing variants, critical role of the IL-36 family of cytokines in disease pathophysiology, and treatment perspectives for pustular psoriasis. We further outline the application of appropriate mouse models for the study of pustular psoriasis and address the outstanding questions and issues related to our understanding of the mechanisms involved in pustular psoriasis.
