FOREMOST post hoc analysis: Predictors of progression to polyarticular PsA, and the effect of apremilast

Results from a post hoc analysis of the phase IV FOREMOST (NCT03747939) trial, evaluating apremilast in 308 patients with early oligoarticular psoriatic arthritis (PsA), were published in Rheumatology by Coates et al. The primary objectives were to determine predictors of progression from oligoarticular (≤4 active joints) to polyarticular (>4 active joints) PsA at 16 weeks and to establish the effect of apremilast on progression. 

Key data: At baseline, 87.0% of patients had oligoarticular PsA. By Week 16, 25.1% of patients had progressed to polyarticular PsA. Apremilast reduced the odds of progression to polyarticular PsA by 58% vs placebo (odds ratio [OR], 0.42; 95% confidence interval [CI], 0.22–0.77). The odds of progression in the placebo group were greater in patients who were female (OR, 3.35; 95% CI, 1.20–9.34), conventional synthetic disease-modifying antirheumatic drug (csDMARD)-naïve (OR, 3.42; 95% CI, 1.18–9.93), and who had dactylitis (OR, 9.26; 95% CI, 1.32–65.09). Low rates of disease progression, as well as improvements in disease activity, were maintained for up to 48 weeks in the apremilast group, with no new safety signals reported. 

Key learning: Apremilast reduced the odds of progression to polyarticular PsA in patients with early oligoarticular PsA, with low rates of progression, and improvements in disease activity, maintained through 48 weeks.