In the Study of Etanercept and Methotrexate in Combination or as Monotherapy in Subjects with Psoriatic Arthritis (SEAM-PsA), a 48-week, phase III, randomized controlled trial that compared outcomes with methotrexate (MTX) monotherapy, etanercept (ETN) monotherapy, and MTX+ETN combination therapy in patients with psoriatic arthritis (PsA) who were unfamiliar with MTX and biosimilars, researchers looked at the potential effects of sex and body mass index (BMI) on response.

They assessed important outcomes, such as the American College of Rheumatology 20 (ACR20) criteria, minimal disease activity (MDA), very low disease activity (VLDA), and Psoriatic Arthritis Disease Activity Score (PASDAS), at week 24, stratified by gender (male vs. female) and BMI (kg/m2; ≤ 30 vs.> 30). Descriptive statistics, normal approximation, a logistic model, and an analysis of covariance were all used in the data analysis.

The SEAM-PsA experiment was completed by 851 patients in total. Men had higher rates of ACR20 (71.5% vs 58.3%; P=0.02), MDA (45.8% vs 25.2%; P=0.0003); VLDA (19.1% vs 9.5%; P=0.03); and PASDAS (-3.0 vs -2.3; P=0.0004; than women who underwent MTX+ETN combination treatment). For ACR20, MDA, VLDA, and PASDAS, patients with BMI less than or equal to 30 typically had better results than those with BMI more than 30; however, there was no clear pattern identifying the treatment arm in which the difference occurred.

MDA and PASDAS showed improved results with MTX+ETN combination treatment more frequently in males than in women. There was no obvious trend regarding the therapy administered; however, patients with BMIs less than or around 30 had better results than those with BMIs more than 30 overall.