A meta-analysis of the role of p38 mitogen-activated protein kinase inhibitors in patients with active rheumatoid arthritis

The role of p38 mitogen-activated protein kinase (MAPK) inhibitors for treating rheumatoid arthritis (RA) is debated. Therefore, we performed a meta-analysis of all published randomized controlled trials (RCTs) to evaluate the efficacy and safety of p38 MAPK inhibitors in patients with active RA. Searches were conducted in the databases PubMed, EMBASE, and Cochrane Library. We identified three articles including four RCTs with analysis on the efficacy and safety of p38 inhibitors for the treatment of RA. Our meta-analysis showed that a better American College of Rheumatology 20 % improvement (ACR20) was observed in the p38 inhibitors group compared with the placebo group, but there were no meaningful differences in ACR50, Disease Activity Score in 28 joints response, and CRP levels between two groups past week 12. The overall adverse events were similar between placebo and treatment groups. In conclusion, p38 MAPK inhibitors showed modest efficacy in patients with RA. However, this conclusion is based on the small number of available studies and inadequate sample size, and more well-designed RCTs will be necessary to determine the role of p38 MAPK inhibitors in RA.