medwireNews: Ustekinumab elicits a greater clinical response versus placebo in patients with psoriatic arthritis (PsA) naïve to tumor necrosis factor (TNF) inhibitors, regardless of prior conventional synthetic (cs)DMARD or methotrexate exposure, PSUMMIT 1 and PSUMMIT 2 study data show.
Iain McInnes, from the University of Glasgow in the UK, and study co-authors explain that “greater proportions of ustekinumab-treated patients achieved ACR20/50/70 responses and DAS28-CRP response and remission compared with placebo at week 24” regardless of prior treatment.
They add that “[t]he patients in this analysis represent the heterogeneity of patients with PsA in real-world clinical practice.”
There were three treatment populations – TNF-naïve (n=747), methotrexate- and TNF-naïve (n=179), and csDMARD- and TNF-naïve (n=146) – all of whom were randomly assigned to treatment with either intravenous ustekinumab 45 mg or 90 mg at weeks 0, 4, and every subsequent 12 weeks, or placebo at weeks 0, 4, and 16 with crossover to ustekinumab 45 mg at week 24.
Of the 499 TNF-naïve patients who received ustekinumab, 47.5%, 26.5%, and 12.8% achieved an ACR20, 50, and 70 response after 24 weeks, respectively, compared with significantly lower values of 23.8%, 8.5%, and 2.8% of the 228 TNF-naïve patients given placebo.
Similarly, among the 123 ustekinumab-treated patients who were methotrexate- and TNF-naïve, a respective 53.7%, 35.0%, and 19.5%, achieved ACR20, 50, and 70 responses, compared with 17.9%, 12.5%, and 3.6% of 56 similar patients given placebo.
And for the 101 csDMARD- and TNF-naïve patients given ustekinumab, the response rates were a corresponding 56.4%, 37.6%, and 19.8%, compared with 20.0%, 15.6%, and 4.4% for the 54 given placebo.
The researchers note that the proportions of TNF-naïve patients who achieved ACR20, 50, or 70 responses was similar among those with PsA durations of less than 1 year, between 1 and 3 years, and more than 3 years.
Ustekinumab was also superior to placebo in terms of DAS28-CRP response and remission in all three prior-treatment groups. And patients treated with ustekinumab were more likely than those given placebo to have resolution of enthesitis and dactylitis, and a lower mean change from baseline in total PsA-modified van der Heijde–Sharp Score. However, these outcomes were only statistically significant within the TNF-naïve population.
Writing in RMD Open, McInnes et al conclude: “These results suggest that ustekinumab could be considered an appropriate treatment option for biologic-naïve patients with PsA irrespective of previous csDMARD therapy and disease duration.”
By Hannah Kitt
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