Vinod Chandran, MBBS, MD, DM, PhD
Treatment of psoriatic arthritis (PsA) was the focus of clinical research papers published this month. Despite the advances made in treating PsA with targeted therapies, in most parts of the world, conventional disease-modifying antirheumatic drugs (DMARDs) are the first line of treatment. Methotrexate (MTX) and leflunomide (LEF) are commonly used, but there are limited data on the effectiveness of combination therapy. To address this issue, Mulder and colleagues enrolled 78 patients with active PsA who have two or more swollen joints and randomly allocated them to either 25 mg oral MTX weekly after 4 weeks of 15 mg weekly plus 20 mg LEF daily (n = 39) or MTX plus placebo (monotherapy; n = 39). At week 16, PsA disease activity score was improved significantly in the MTX + LEF vs. MTX monotherapy group (3.1 vs. 3.7; P = .025). Incidence of mild adverse events, such as nausea/vomiting (44% vs. 28%) and altered bowel habits (26% vs. 8%), was higher with MTX + LEF vs. MTX + placebo. So although less well tolerated, MTX + LEF therapy was superior to MTX monotherapy at improving disease activity in patients with PsA.
Biologics targeting tumor necrosis factor (TNF), interleukin (IL) -12/23, -23, and -17A are efficacious for the management of PsA, but questions remain about comparative effectiveness. Gossec and colleagues reported the results from their prospective observational PsABio study that evaluated real-world treatment persistence and effectiveness at 1 year after initiation of first-line to third-line IL-12/23 inhibitor ustekinumab or a TNF inhibitor (TNFi). Their study followed 893 patients. After 1 year of treatment, ustekinumab and the TNFi showed similar persistence (hazard ratio [HR] for stopping/switching treatment 0.82; 95% CI 0.60-1.13) and a similar proportion of patients achieving (on the Disease Activity Index for PsA) clinical low disease activity (odds ratio [OR] 0.80; 95% CI 0.57-1.10) and remission (OR 0.73; 95% CI 0.49-1.07), along with similar safety profiles. Thus in real-world studies, TNFi and ustekinumab seem to have similar effectiveness and safety.
Drug persistence between patients with psoriasis alone vs. those with PsA is also of interest. In a real-life study including 62 patients with psoriasis and 90 patients with PsA who initiated treatment with secukinumab and were followed up for 24 months or until discontinuation, Ortolan and colleagues demonstrated that the retention rate of secukinumab was higher in psoriasis vs. PsA at 12 (85% vs. 68%) and 24 (61% vs. 57%) months, with the risk for secukinumab discontinuation being higher among patients with PsA in the overall cohort (HR 2.43; P = .035) and in patients with obesity in the PsA cohort ( P = .021). Thus, the presence of PsA and obesity lower the secukinumab retention rate.
- Despite the advent of many targeted therapies for PsA, there remain many unmet needs. Deucravacitinib is a novel oral selective inhibitor of tyrosine kinase 2 (TYK2) acting via binding to the TYK2 regulatory domain. In a phase 2 study including 203 patients with active PsA that was intolerant to at least one therapy who were randomly assigned to receive 6 mg deucravacitinib once daily, 12 mg deucravacitinib once daily, or placebo for 16 weeks, Mease and colleagues demonstrated that at week 16, American College of Rheumatology 20 (ACR20) response was significantly higher with 6 mg once-daily deucravacitinib (52.9%, adjusted OR [aOR] 2.4; P = .0134) and 12 mg (62.7%, aOR 3.6; P = .0004) vs. placebo (31.8%), with 12 mg deucravacitinib improving ACR20 response as early as at 8 weeks ( P < .05). No serious adverse events were reported. Thus, TYK2 inhibition shows promise in the treatment of PsA and the results from phase 3 trials are awaited.