Guselkumab improves ACR20 rates to 58.6% and 62.2% in patients with psoriatic arthritisTrial shows guselkumab helps adults with psoriatic arthritis

OBJECTIVE: To evaluate the efficacy and safety of guselkumab, an interleukin-23p19 subunit inhibitor, in participants with active psoriatic arthritis (PsA) and inadequate response (inadequate efficacy and/or intolerance) to one prior tumor necrosis factor (TNF) inhibitor. METHODS: In SOLSTICE (phase 3b, randomized, multicenter, double-blind, placebo-controlled study), enrolled adults with active PsA (three or more swollen joints; three or more tender joints; C-reactive protein ≥ 0.3 mg/dL) and inadequate response to one prior TNF inhibitor were randomized to guselkumab 100 mg every 4 weeks (Q4W), guselkumab 100 mg at weeks 0 and 4 and then Q8W, or placebo with crossover to guselkumab Q4W at week 24. The primary endpoint was ≥20% improvement in American College of Rheumatology criteria (ACR20) at week 24. Secondary endpoints included ACR50, ACR70, Investigator's Global Assessment of psoriasis (IGA) score of 0 or 1 with ≥2-grade improvement, ≥90% improvement in Psoriasis Area and Severity Index (PASI90), and minimal disease activity (MDA) at week 24 and were analyzed by intention-to-treat. RESULTS: Analyses included 451 randomized participants (Q4W n = 150; Q8W n = 151; placebo n = 150). At week 24, significantly greater proportions of guselkumab (Q4W/Q8W)-treated participants versus placebo-treated participants, respectively, achieved ACR20 (primary endpoint: 58.6%/62.2% vs 34.8%), ACR50 (31.4%/32.1% vs 12.2%), ACR70 (17.5%/17.3% vs 2.0%), IGA 0/1 response (50.0%/57.3% vs 17.4%), PASI90 (49.4%/45.5% vs 12.0%), and MDA (18.8%/23.9% vs 5.4%) (all P < 0.001). Through week 24, 46.7%, 53.6%, and 48.3% of participants receiving guselkumab Q4W, guselkumab Q8W, and placebo, respectively, had one or more adverse event. One death occurred (myocardial infarction). CONCLUSION: Comparable efficacy was observed with both guselkumab regimens in participants with active PsA and inadequate response to one prior TNF inhibitor; safety findings were consistent with the known profile of guselkumab in patients with psoriatic disease.