Background Switching between biologic agents nowadays is a common procedure when treating Rheumatoid Arthritis (RA) patients. However, there is no optimal treatment strategy available and switching biologic therapies still is an individual decision. The Utrecht Arthritis Cohort Study Group (SRU), a consortium of 7 hospitals in the surroundings of Utrecht was founded in order to create large databases by collecting clinical data from RA patients who are treated in the outpatients clinics of the collaborating hospitals. In this interim analysis we address habits of switching biologic DMARDs within the SRU.
Objectives To give an interim overview about switching habits within a Dutch population in daily life.
Methods A total of 207 patients, diagnosed with RA according to the 1987 revised ACR criteria or the 2010 ACR / EULAR Rheumatoid ArthritisClassification Criteria, who are in care within the SRU were included into the observation. They were receiving biologic therapies according to daily clinical practice. Each observation period began with the beginning of each (new) biological treatment and lasted up to 12 months. No specific treatment strategy was followed, although the patients were regularly seen every 3 months. Clinical evaluations including the DAS28 and a documentation of medication changes and side effects were performed at every visit.
Results A total of 768 visits from 207 individual patients was available for analysis. 129 patients (63%) were TNF naïve, the others had already switched at least once before the observation period had begun. There were no significant differences regarding concomitant conventional DMARDs and prednisone use. In total, 39 of the 207 (18%) patients switched therapy at least once (32 once, 6 twice, 1 three times). Switching from one anti-TNF agent to another (including Etanercept) was seen most frequently (21 x/ 46%), followed by anti-TNF to Rituximab (8x / 17%) and anti-TNF to Tocilizumab (6x/ 13%). The main reason for switching was lack of efficacy (68%), reflected by a mean DAS 28 of 4.5 (±1.4) at the time of switching. 3 months after the change in medication a significant mean DAS 28 improvement could be observed (4.5 vs 3.4, p<0.001). However, at this stage of the observation, switching between anti-TNF therapies turned out to be less effective than switching in any other direction, although not significantly different (mean DAS 28 improvement -0.7 vs -1.4, respectively, p=0.28)
Adverse reactions were only responsible for 8.5% of medication changes, although mild side effects (mainly to the skin) were reported in 111 (14%) of the visits. Another 35 patients stopped biologic therapy for irreproducible reasons whatsoever.
Conclusions In this observational cohort switching therapies was a common procedure. Although switching between anti-TNF therapies is most common, moving on to biologic therapies other than anti-TNF seems to be more effective.
Acknowledgements This research was conducted while K. Brickmann was an ARTICULUM Fellow
Disclosure of Interest None Declared