Effect on efficacy and safety trial outcomes of also enrolling patients on ongoing glucocorticoid therapy in rheumatoid arthritis clinical trials of tocilizumab or adalimumab or methotrexate monotherapy.

Background: In rheumatoid arthritis (RA) trials, inclusion of patients on background treatment with glucocorticoids (GCs) might impact efficacy and safety outcomes.

Objectives: To determine if inclusion of patients on background GC use influenced efficacy and safety outcomes of RA randomised clinical trials on initiation of tocilizumab (TCZ) or adalimumab (ADA) or methotrexate (MTX) monotherapy.

Methods: Data of four double-blind RA randomised controlled trials (AMBITION, ACT-RAY, ADACTA and FUNCTION) with in total four TCZ, one ADA and two MTX monotherapy arms were analysed. Analyses of covariance of changes from baseline to week 24 in efficacy endpoints and radiographic progression up to week 104 were performed, correcting for relevant covariates. Incidence rates of serious adverse events (SAEs) were assessed.

Results: No statistically significant differences were found in efficacy parameters between background GC users and non-GC users, except for less radiographic progression associated with GC usage in one MTX arm. SAE rates were not statistically significantly different between GC users and non-GC users in the treatment arms.

Conclusion: No effect of including patients on background GC treatment on efficacy and safety trial outcomes was found, with the exception of reduced radiological joint damage in one MTX arm.