Deucravacitinib for the treatment of psoriatic arthritis: the evidence so far

Psoriatic arthritis (PsA) is a heterogeneous disease that may develop in up to 30% of patients with psoriasis. PsA mainly involves peripheral joints; however, axial skeleton and entheses can also be involved. PsA is the result of a complex interplay between an individual's genotype and environmental factors that triggers an immune response and leads to the production of a cytokine cascade. Even though there are about 17 targeted therapies for PsA, a significant percentage of patients fail to respond to such treatments, have a partial response or develop side-effects. This article aims to review the current knowledge on deucravacitinib, a new oral small molecule that selectively inhibits tyrosine kinase 2 (TYK2), for the treatment of PsA. TYK2, a member of the Janus kinase (JAK) family, is responsible for mediating intracellular signalling of cytokines involved in the pathogenesis of PsA and psoriasis, namely IL-12, IL-23, and type I interferons. Recently, deucravacitinib was approved by the FDA for the treatment of moderate-to-severe plaque psoriasis and is currently being evaluated in phase III clinical trials in PsA. In a phase II clinical trial, deucravacitinib showed sustained effectiveness in several domains of PsA, namely arthritis, enthesitis and dactylitis, was well tolerated, and had a favourable safety profile. In patients with psoriasis, deucravacitinib had shown a higher efficacy than placebo and apremilast. Deucravacitinib is a promising therapy, with a unique mechanism of action. Results from the phase III programme and studies evaluating long-term response and head-to-head comparisons with other targeted agents will be important to establishing the position of deucravacitinib in the management of PsA.