Etanercept, a soluble recombinant tumor necrosis factor (TNF) receptor fusion protein, is indicated for the treatment of rheumatoid arthritis (RA), psoriatic arthritis, and ankylosing spondylitis. Fifty mg every week or 25 mg twice a week has been approved as the standard dose for the drug. However, recent studies have demonstrated that it is feasible to reduce the dose of anti-TNF without compromising the efficacy in a major proportion of the subjects having low disease activity state. In addition, dose reduction also contributed to significant savings, in terms of the cost of the annual biological disease-modifying antirheumatic drug (bDMARD). However, dose reductions can lead to loss of effect and enhanced immunogenicity.
The findings of an 18-month, open-label, randomized controlled trial, published in the Scandinavian Journal of Rheumatology, have concluded that etanercept tapering is feasible without impairing the efficacy in RA, PsA, and AS patients in sustained minimal disease activity (MDA). The majority of the patients could discontinue the treatment for a period of 6 months and reduced drug concentrations were found to be sufficient to regulate the disease activity. However, the risk of minor and major flares was found to be significant, even in patients on standard doses.
The intervention group discontinued etanercept 6 months after doubling the dosing interval at baseline. The control group doubled the dosing interval after continuing the standard dose for 6 months. The study has noted the persistence of MDA status in 47 and 56 (74%) patients in the intervention and control groups respectively. The median etanercept concentrations decreased from 1.50 μg/mL to 0.46 μg/mL (0.28–0.92). Around 40% successfully discontinued the drug with the maintenance of MDA for at least 6 months.
The present study is touted as one of its kind assessing etanercept levels during tapering. Although there is limited literature evidence on minimum necessary concentration, the present findings indicate that low concentrations of etanercept are sufficient to control disease in the majority of the subjects upon attainment of MDA.
Reference: Ruwaard J, L’ Ami MJ, Kneepkens EL, et al. Interval prolongation of etanercept in rheumatoid arthritis, ankylosing spondylitis, and psoriatic arthritis: a randomized controlled trial [published online ahead of print, 2022 Mar 2]. Scand J Rheumatol. 2022;1-8.