Experimental and Investigational Pharmacotherapy for Psoriatic Arthritis: Drugs of the Future

Early psoriatic arthritis: clinical and therapeutic challenges

INTRODUCTION

Psoriatic arthritis (PsA) is a chronic immunoinflammatory disease of the enthesis and adjacent synovium, skin, and nail, which early diagnosis may be crucial for starting a prompt therapeutic intervention. Theoretically, early treatment offers the advantage of acting on the reduction of the articular damage progression since initial phases of the disease.

AREAS COVERED

This review explores the challenges of clinical-diagnostic aspects and the underlying pathophysiology of early PsA phases, as well as the evidence evaluating the impact of early intervention on disease outcomes.

EXPERT OPINION

Main instruments for early PsA diagnosis include recognizing synovial-entheseal inflammatory signs at onset, improving screening PsA high-risk subjects, and increasing disease knowledge of physicians and patients with psoriasis or familial history. PsA continues to significantly impact on the Quality of Life of patients affected by the disease, making necessary to deeply study clinical manifestations, risk factors, and underlying immunoinflammatory mechanisms, as well as to identify biomarkers for early identification. Additionally, it remains a need to increase more evidence on understanding how early treatment of PsA and of psoriasis might influence the course of the disease.

Osteoarthritis versus psoriasis arthritis: Physiopathology, cellular signaling, and therapeutic strategies

Osteoarthritis and psoriasis arthritis are two degenerative forms of arthritis that share similar yet also different manifestations at the histological, cellular, and clinical levels. Rheumatologists have marked them as two entirely distinct arthropathies. Given recent discoveries in disease initiation and progression, potential mechanisms, cellular signaling pathways, and ongoing clinical therapeutics, there are now more opportunities for discovering osteoarthritis drugs. This review summarized the osteoarthritis and psoriasis arthritis signaling pathways, crosstalk between BMP, WNT, TGF-β, VEGF, TLR, and FGF signaling pathways, biomarkers, and anatomical pathologies. Through bench research, we demonstrated that regenerative medicine is a promising alternative for treating osteoarthritis by highlighting significant scientific discoveries on entheses, multiple signaling blockers, and novel molecules such as immunoglobulin new antigen receptors targeted for potential drug evaluation. Furthermore, we offered valuable therapeutic approaches with a multidisciplinary strategy to treat patients with osteoarthritis or psoriasis arthritis in the coming future in the clinic.

JAK Inhibitors in Psoriatic Disease

Psoriasis is now considered to be the cutaneous phenotype of a systemic inflammatory condition, recognized under the term Psoriatic Disease (PsD). PsD has several extracutaneous manifestations, such as inflammatory articular and entheseal involvement, leading to psoriatic arthritis (PsA), and the less frequent intestinal and ocular manifestations with colitis/inflammatory bowel disease and uveitis, respectively. There have also been several reports of an increased frequency of comorbidities such as hypertension, diabetes, dyslipidemia, obesity, metabolic syndrome and cardiovascular manifestations during the course of PsD. The link between psoriasis and related comorbidities is considered a long-term disease sequela, often characterized by an unhealthy lifestyle and a consequence of systemic inflammation; hence, psoriasis requires adequate and prompt treatment, with the aim of controlling not only cutaneous manifestations but also extracutaneous manifestations and systemic inflammation. Pharmacological strategies for PsD have significantly increased over recent years. Recently, the targeted synthetic DMARDs, Janus kinase (JAK) inhibitors, tofacitinib and upadacitinib, were added to the therapeutic armamentarium for treating PsA, and deucravacitinib for psoriasis. These oral agents act directly on inflammatory mechanisms underlining the disease, as antagonists of the intracellular JAK signal pathway and, by STAT phosphorylation, inhibit gene proinflammatory cytokine transcription. JAK inhibitors represent a recent additional treatment strategy for PsD management and, among these, tofacitinib and upadacitinib have recently been approved for PsA, and deucravacitinib for psoriasis. In this review we describe ongoing and recent phase II and III randomized controlled trials (RCTs) evaluating the efficacy and safety of investigational JAK inhibitors in psoriasis and PsA.

Kv1.3 K+ Channel Physiology Assessed by Genetic and Pharmacological Modulation

Potassium channels are widespread over all kingdoms and play an important role in the maintenance of cellular ionic homeostasis. Kv1.3 is a voltage-gated potassium channel of the Shaker family with a wide tissue expression and a well-defined pharmacology. In recent decades, experiments mainly based on pharmacological modulation of Kv1.3 have highlighted its crucial contribution to different fundamental processes such as regulation of proliferation, apoptosis, and metabolism. These findings link channel function to various pathologies ranging from autoimmune diseases to obesity and cancer. In the present review, we briefly summarize studies employing Kv1.3 knockout animal models to confirm such roles and discuss the findings in comparison to the results obtained by pharmacological modulation of Kv1.3 in various pathophysiological settings. We also underline how these studies contributed to our understanding of channel function in vivo and propose possible future directions.

Persistence of C-reactive protein increased levels and high disease activity are predictors of cardiovascular disease in patients with axial spondyloarthritis

An accurate prediction of cardiovascular (CV) risk in patients with Axial Spondyloarthritis (axSpA) is a strong unmet need, as CV risk algorithms poorly perform in these subjects. The aim of this study was to establish whether the persistence of high C-reactive protein (CRP) and high disease activity may be considered predictive factors of CVD in axSpA. 295 patients without personal history of CVD, were consecutively enrolled in this study. To evaluate the relationship between CV events occurrence (fatal and non-fatal) and the persistence of increased CRP levels, ASDAS (Ankylosing Spondylitis Disease Activity Score) > 2.1, and BASDAI (Bath Ankylosing Spondylitis Disease Activity) > 4 during the follow-up, univariable and multivariable Cox Proportional Hazard Models have been performed. During follow-up (we analyzed 10-years retrospective data), 23 patients had a CV event. Multivariable Cox Proportional Hazard Models showed a strong association between CV event and the persistency of increased CRP levels (namely, percentage of visits in which CRP levels were increased) (HR = 1.03; 95%CI 1.015-1.045; p < 0.001), of ASDAS > 2.1 (HR = 1.014, 95%CI 1.000-1.028, p = 0.047), and of BASDAI > 4 (HR 1.019, 95%CI 1.006-1.033, p = 0.006) during follow-up, after adjustment for age, sex, and diabetes. This study suggests that persistence of increased CRP levels and high disease activity may be considered biomarkers to identify those axSpA patients at higher risk of CVD. Innovative axSpA-specific CV risk score, including these variables, have to be developed.