Deucravacitinib, an oral, selective, allosteric tyrosine kinase 2 inhibitor, in Japanese patients with moderate to severe plaque, erythrodermic, or generalized pustular psoriasis: Efficacy and safety results from an open-label, phase 3 trial

Phase 2 Trial of Deucravacitinib in Psoriatic Arthritis: Biomarkers Associated With Disease Activity, Pharmacodynamics, and Clinical Responses

OBJECTIVE

Our objective was to evaluate the association of serum biomarkers with baseline psoriatic arthritis (PsA) disease activity, pharmacodynamic effects of deucravacitinib on biomarker levels, and the relationship between biomarkers and clinical responses to deucravacitinib.

METHODS

The phase 2 trial (ClinicalTrials.gov identifier: NCT03881059) randomly assigned 203 patients with PsA 1:1:1 to placebo, deucravacitinib at 6 mg once daily (QD), or deucravacitinib at 12 mg QD. Serum biomarkers associated with the interleukin 23 (IL-23) pathway (IL-17A, β-defensin [BD-2], and IL-19), type I interferon pathway, inflammation, and collagen matrix turnover were measured by immunoassay. Clinical responses (≥75% improvement from baseline in the Psoriasis Area and Severity Index [PASI75] and ≥20% improvement from baseline in American College of Rheumatology criteria [ACR20] responses) were measured at week 16. Hematologic variables were also assessed.

RESULTS

IL-17A, BD-2, and IL-19 had a modest association with PASI scores (r = 0.4, r = 0.56, and r = 0.5, respectively) at baseline. In deucravacitinib groups, IL-17A, BD-2, IL-19, C-X-C motif ligand 9 (CXCL9), CXCL10, C-reactive protein, matrix metalloproteinase 3, and collagen type 4 degradation marker levels were significantly reduced at week 16 versus baseline (P < 0.01); higher levels of IL-23 pathway-associated biomarkers predicted higher PASI75 and ACR20 response rates in deucravacitinib-treated patients. Significantly higher PASI75 response rates were seen in patients with high baseline IL-17A (odds ratio 15.76) and BD-2 levels (odds ratio 15.41) versus low baseline IL-17A and BD-2 levels. Changes in hematologic variables that are characteristic of JAK inhibition were not observed with deucravacitinib.

CONCLUSION

Deucravacitinib significantly impacted biomarkers associated with Tyk2 signaling pathways of key inflammatory cytokines, including IL-23 and type I interferon, and those related to collagen matrix turnover. These biomarkers may predict treatment responses to deucravacitinib.

Therapeutic Potential of Targeting the JAK/STAT Pathway in Psoriasis: Focus on TYK2 Inhibition

Psoriasis is an inflammatory skin disease with a chronic relapsing course and an often-detrimental impact on patients' quality of life. Thanks to incredible advances in research over the past few decades, the therapeutic armamentarium of psoriasis is now reasonably broad and structured, with several therapeutic agents that have demonstrated successful long-term control of this condition. However, there are still unfulfilled gaps resulting from the inherent limitations of existing therapies, which have paved the way for the identification of new therapeutic strategies or the improvement of existing ones. A great deal of attention has recently been paid to the JAK/STAT pathway, playing a crucial role in chronic inflammatory skin diseases, including psoriasis. Indeed, in a disease with such a complex pathogenesis, the possibility to antagonize multiple molecular pathways via JAK/STAT inhibition offers an undeniable therapeutic advantage. However, data from clinical trials evaluating the use of oral JAK inhibitors in immune-mediated disorders, such as RA, have arisen safety concerns, suggesting a potentially increased risk of class-specific AEs such as infections, venous thromboembolism, and malignancies. New molecules are currently under investigation for the treatment of psoriasis, such as deucravacitinib, an oral selective inhibitor that binds to the regulatory domain of TYK2, brepocitinib (PF-06700841) and PF-06826647 that bind to the active site in the catalytic domain. Due to the selective TYK2 blockade allowing the inhibition of key cytokine-mediated signals, such as those induced by IL-12 and IL-23, anti-TYK2 agents appear to be very promising as the safety profile seems to be superior compared with pan-JAK inhibitors. The aim of our review is to thoroughly explore the rationale behind the usage of JAK inhibitors in PsO, their efficacy and safety profiles, with a special focus on oral TYK2 inhibitors, as well as to provide a forward-looking update on novel therapeutic strategies targeting the TYK2 pathway in psoriasis.