Key clinical point: Neither antiadalimumab antibodies nor adalimumab serum levels (ADL) were significant predictors of response to subsequent TNFi or non-TNFi in RA patients who failed adalimumab therapy.

Major finding: The sensitivity and specificity of antidrug antibodies for patients who switched to a TNFi was 18% and 75%, respectively and 33% and 70% for those who switched to a non-TNFi; results were similar for ADL.

Study details: The data come from a retrospective cohort study of 137 adults with rheumatoid arthritis.

Disclosures: The study received no external funding. The researchers had no financial conflicts to disclose.

Commentary

“In implementation of a treat-to-target strategy for RA, careful choice of subsequent drugs when switching is of importance in preventing loss of time, money, and function. One question is whether we can predict response in patients switching from one anti-TNF to another, and what markers we have that can plausibly do so. Previous studies have suggested that anti-drug antibodies to adalimumab and infliximab can predict response to a second anti-TNF, but not whether another class of biologic DMARDs is preferable.

This retrospective study did not show a predictive for anti-drug antibodies or random adalimumab levels in terms of clinical response to a second anti-TNF or non-TNF inhibitor after failure of adalimumab. A prospective study might be helpful as patients who had these levels tested might be different as a group than those who were. For now, it is not clear that the prescription of a second biologic should be predicated on these values.”

Arundathi Jayatilleke, MD

Lewis Katz School of Medicine, Temple University