Among patients with psoriatic arthritis treated with guselkumab, early joint improvement by week 8 predicts lower radiographic progression rates through 2 years, according to data published in Clinical Rheumatology.
“Structural joint damage occurs in up to half of patients with PsA within 2 years of developing clinical symptoms, and can be characterized by bone erosion and joint space narrowing (JSN), as well as new bone formation,” Philip J. Mease, MD, of the Swedish Medical Center and the University of Washington, in Seattle, and colleagues wrote. “Guselkumab, a fully human monoclonal antibody that targets the IL-23p19 subunit, was approved to treat adults with active PsA based on findings from the phase 3 DISCOVER-1 and DISCOVER-2 trials.”
Philip J. Mease
To investigate whether early clinical improvement in joint activity can predict future disease course in patients with PsA receiving guselkumab (Tremfya, Janssen), Mease and colleagues conducted a post-hoc analysis of data from DISCOVER-2, a phase 3, double-blind, placebo-controlled, multicenter study. Patients were eligible if they were aged 18 years or older, had active PsA and had a current or historical instances of psoriasis. Included patients additionally had responded poorly to, or could not receive, NSAIDs or conventional synthetic disease-modifying antirheumatic drugs (DMARDs), and were naïve to biologics and Janus kinase inhibitors.
Patients had been randomized 1:1:1 to receive either 100 mg of guselkumab every 4 weeks; the same dose at weeks 0 and 4, and then every 8 weeks thereafter; or placebo with crossover at week 24 to guselkumab 100 mg every 4 weeks. The researchers collected radiographs of the hands and feet at baseline and weeks 24, 52 and 100. Radiographs were evaluated by independent readers, and, when necessary, a third reader provided additional judgment. Disease assessment at week 8 was based on Disease Activity Index in PsA (DAPSA).
The analysis included 739 patients. Overall, baseline age, disease duration, C-reactive protein levels and swollen joint counts correlated “weakly” with baseline PsA-modified van der Heijde-Sharp (vdH-S) scores. According to the researchers, patients who demonstrated elevated C-reactive protein levels and vdH-S scores at baseline had greater radiographic progression through 100 weeks (P < .0001). A greater improvement in DAPSA by week 8 in patients receiving guselkumab was linked to less severe radiographic progression through 100 weeks (P=.0096), they added.
“In this post hoc analysis of data from the phase 3 DISCOVER-2 study of guselkumab-treated biologic-naïve patients with active PsA, earlier (week 8) DAPSA improvement was a significant predictor of less [radiographic progression] through 2 years,” Mease and colleagues wrote. “Thus, the early and sustained control of joint disease activity with guselkumab may modify the overall long-term PsA disease trajectory to a milder course.”