Background/Purpose: Most randomized control trials (RCTs) for psoriatic arthritis (PsA) include patients with asymmetric oligoarthritis (AO) and  polyarthritis (PA). There are limited data from RCTs on the demographic and disease characteristics of PsA patients with either AO or PA and how these different patient groups respond to treatment. Our analyses compared baseline characteristics and treatment outcomes of AO and PA patients receiving ETN 50 mg QW for 24 wks in the PRESTA trial.

Methods: PRESTA was a large, randomized, 24-wk, multicenter study to evaluate the efficacy and safety of etanercept (ETN) in patients with moderate-to-severe psoriasis (≥10% of body surface) and active PsA ≥3 months. Patients received ETN 50 mg BIW or 50 mg QW for 12 wks in a double-blind phase, and open-label ETN 50 mg QW for 12 additional wks. Patients who received ETN 50 mg QW for 24 wks were included in this analysis if they received ≥1 dose of ETN and had ≥1 post-baseline efficacy value. AO (inflammation of 2-4 joints) and PA (inflammation of ≥5 joints) was based on clinical diagnosis by rheumatologists.  Standard clinical outcomes were assessed among patients with AO or PA at baseline.

Results: A total of 363 subjects (46 with baseline AO, 317 with baseline PA) were included in these analyses. At baseline, patients with PA were significantly older (47.6 vs 43.0 years, P=0.01) and had significantly higher HAQ, PGA of arthritis, PGA of psoriasis, subject assessment of joint pain and numbers of painful and swollen joints than those with AO (Table). Significant improvement at wk 24 was observed for all endpoints in both groups; mean % change and adjusted mean change from baseline were similar for PA vs AO patients at wk 24. At 24 wks, a significantly greater proportion of AO than PA patients achieved HAQ ≤0.5 (Table). The proportion of patients achieving ACR/20/50/70, PASI75, and PGA of psoriasis ≤1 was not significantly different between AO and PA groups. Similar results between the 2 groups were observed after 12 wks of treatment.

Conclusion: ETN 50 mg QW was effective in the treatment of PsA regardless of the subtype examined.  As expected, AO patients had less baseline joint disease but achievement of low level joint disease activity at 24 wks was similar in PA and AO groups, whereas functional improvement was greater in the AO group. Similar significant improvement in skin disease was observed in both patients with PA and AO.

ACR Meeting Abstracts - https://acrabstracts.org/abstract/baseline-characteristics-and-treatment-outcomes-in-psoriasis-patients-with-polyarthritis-or-oligoarthritis/