medwireNews: Golimumab slows radiographic progression in patients with psoriatic arthritis (PsA), regardless of the extent of disease activity achieved or the composite index used to measure it, GO-VIBRANT study data show.
As previously reported by medwireNews, primary results from the phase 3 GO-VIBRANT trial found that ACR20 response rates were significantly higher among PsA patients treated with the tumor necrosis factor (TNF)-α inhibitor golimumab (2 mg/kg on weeks 0, 4, 12, and 20) than among those who received placebo.
But Philip Mease (University of Washington School of Medicine, Seattle, USA) and colleagues note in Arthritis Research & Therapy that PsA is a disorder with diverse manifestations and it is important to take these into account.
The researchers therefore conducted post-hoc analyses of the GO-VIBRANT data to assess changes in radiographic progression in patients with varying levels of composite index-defined disease activity.
They found that at week 24 mean total PsA-modified Sharp/van der Heijde score (SHS) had fallen by 0.36 points in the golimumab group and increased by 1.95 points in the placebo group, a statistically significant difference.
When the participants were classified according to whether or not they achieved minimal disease activity (MDA) a similar pattern was observed, but with less pronounced benefit among the patients not achieving MDA.
For those who achieved MDA, mean total PsA-modified SHS scores decreased from baseline by 0.83 points with golimumab and increased by 0.91 points with placebo. Among the patients who did not reach MDA, scores decreased by a mean of 0.05 and increased by a mean of 1.49, respectively, with the differences statistically significant in both groups.
Mease et al comment that the fact that golimumab-treated patients who did not achieve low levels of disease activity “still demonstrated far less progression of structural damage than placebo-randomized PsA patients, [suggests] a direct favorable effect of golimumab on radiographic progression at least partially independent of its effect on disease activity.”
At week 24, patients in the placebo group crossed over to golimumab and the outcomes were reassessed at week 52. At this timepoint, total PsA-modified SHS scores decreased and by a mean of 1.16 and increased by a mean of 0.03 among patients in the golimumab group who did and did not achieve MDA, respectively. Among patients who switched from placebo to golimumab, there were corresponding increases of 1.19 and 1.50.
This shows that “the greater inhibition of structural damage progression observed with [intravenous] golimumab vs placebo at week 24 appeared to be sustained through week 52, despite placebo crossover to golimumab at week 24, indicating prompt treatment can have longstanding implications on structural progression,” the researchers remark.
The team observed similar patterns when disease activity was assessed using the very low disease activity index, Psoriatic ArthritiS Disease Activity Score, Disease Activity in Psoriatic Arthritis score, and Clinical Disease Activity Index composite endpoints.
“Our findings provide additional evidence of a potential uncoupling of clinical and radiographic responses to TNF inhibition in patients with PsA,” Mease and co-authors conclude.
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Arthritis Res Ther 2020; 22: 43