Key clinical point: Patients with psoriatic arthritis (PsA) who responded to tumor necrosis factor inhibitors (TNFi), such as adalimumab and etanercept, had higher serum drug levels (SDL), with non-trough SDL being able to differentiate responders from non-responders with substantial efficacy.
Major finding: At 3 months, patients with higher etanercept SDL (odds ratio [OR] 1.24; P = .018) or higher adalimumab SDL (OR 1.08; P = .047) were significantly more likely to be responders according to the European Alliance of Associations for Rheumatology criteria. A non-trough etanercept SDL of 2.0 µg/mL and adalimumab SDL of 3.6 µg/mL could differentiate between responders and non-responders with ~50% specificity and >60% sensitivity.
Study details: This study included patients with PsA who initiated treatment with adalimumab (n = 104) or etanercept (n = 97).
Disclosures: This study was supported by the UK National Institute for Health and Care Research Manchester Biomedical Research Centre and Versus Arthritis. Two authors declared receiving grant support, consulting fees, or travel fees from various sources, including the sponsors.
Source: Curry PDK et al. Non-trough serum drug levels of adalimumab and etanercept are associated with response in patients with psoriatic arthritis. Rheumatology (Oxford). 2023 (Dec 09) doi: 10.1093/rheumatology/kead666