In the substudy, Dr. Vonkeman and colleagues looked at whether it is possible to predict successful TNFi discontinuation. The study included 531 patients who were randomized to stop TNFi therapy in the POET study, the majority of whom were female (67.4%) with a mean age of 59.8 years and disease duration of at least 10 years. Most of the patients were on their first TNFi agent (86.5%) and most were also receiving methotrexate (87%). Prolonged acceptable disease control was indicated by not needing to restart TNFi treatment over 12 months. Overall, the study found that 50.1% of patients remained in low disease activity or remission over 12 months.
Based on multivariate analysis, the study found that potential clinical predictors of prolonged acceptable disease control after TNFi discontinuation included the type of TNFi used (antibody vs. receptor antagonist), having a short disease duration (less than 10 years) and a Multi-Biomarker Disease Activity (MBDA) score of ≤44.
To place this finding in a clinical context, Dr. Vonkeman described a patient for whom it is likely that TNFi therapy can be successfully stopped: someone who is receiving a TNFi antibody and has a short disease duration and low MBDA score. Dr. Vonkeman said that 70% of patients who fit this description have not had to restart a TNFi after one year of follow up at their clinic.
In contrast, he said, patients who use a receptor antagonist, have longstanding disease, and a high MBDA score are less likely to successfully stop TNFi therapy. In his clinic, only 20% of these patients have not restarted TNFi therapy after one year of follow-up.
Dr. Vonkeman said the most important message to clinicians is “that 50% of the RA patients in stable, low-disease activity while on TNFi can effectively and safely stop TNFi,” and that “the clinical predictors of successfully stopping TNFi are the type of TNFi (antibody vs. receptor antagonist), short disease duration of less than 10 years and an MBDA score of <44.”
Dose-Interval Prolongation of Adalimumab
In a presentation not specifically aimed at patients with RA in remission, but all RA patients, Merel J. l’Ami, MSc, a PhD student at Amsterdam Rheumatology and Immunology Center in Reade, Amsterdam, The Netherlands, presented the results of a study that looked at the effect of prolonging the dosing interval of adalimumab in patients with RA and with high adalimumab serum concentration.6
Citing data showing a wide variation in adalimumab serum concentrations exists in RA patients treated with adalimumab 40 mg every other week, Ms. l’Ami said this is contrary to the one-size-fits-all therapy that is prescribed on the labels for such agents as adalimumab. She also cited data showing that the relationship between adalimumab concentrations and clinical response flattens when adalimumab concentrations exceed 5 µg/mL.7,8 “This shows that the maximum treatment response is achieved with concentrations of 5–8 µg/mL,” she said.
