AB0386 A study of retention and switching rates of 1st line biologics for rheumatoid arthritis

Background Since the introduction of biologics for rheumatoid arthritis (RA) treatment, significant improvements in joint inflammation control, prevention of bone/joint destruction, activities of daily living (ADL), and quality of life (QOL) have been observed. Tumor necrosis factor (TNF) inhibitors, such as anti-TNF drugs and TNF receptor drugs, accounted for the majority of biologics. However, the use of non-TNF inhibitors, including interleukin (IL)-6 receptor antibodies and selective modulators of T-cell co-stimulation, has been approved, and their efficacy has been demonstrated. Objectives This study aimed to analyze the effective usage retention rate of TNF inhibitors and non-TNF inhibitors in RA patients. Methods Among 475 RA patients who were administered biologics up to the end of 2015, 329 patients who had been treated for more than 5 years (treatment initiated before the end of December 2010) since the first introduction of biologics (1st line) were included in this study. These patients were divided into TNF inhibitor (infliximab: IFX, etanercept: ETN, and adalimumab: ADA) and non-TNF inhibitor groups (tocilizumab: TCZ, and abatacept: ABT) to investigate the number of patients who progressed to 2nd or 3rd line therapy by 5 years after introduction, and which biologic was administered as the 2nd or 3rd line therapy in each group. Results Of 329 patients, 67 were men and 262 were women. Patient age ranged between 22 and 83 years with a mean of 58.7±13.5 years. RA disease duration ranged between 1 and 50 years with a mean of 9.6±8.1 years. TNF inhibitors and non-TNF inhibitors were used as 1st line therapy in 278 and 51 patients respectively. In the TNF inhibitor group, IFX, ETN, and ADA were administered to 145, 87, and 46 patients respectively. In the non-TNF inhibitor group, TCZ and ABT were administered to 48 and 3 patients respectively. In the TNF inhibitor group, 94 of 278 patients (33.8%) progressed to 2nd line therapy owing to efficacy attenuation and adverse events. Thirty-four of these patients were switched to TNF inhibitors and 60 to non-TNF inhibitors. Conversely, 6 of 51 patients in the non-TNF inhibitor group (11.8%) advanced to 2nd line therapy, with 2 switching to TNF inhibitors and 4 to non-TNF inhibitors. Additionally, 25 and 3 patients advanced to 3rd line therapy in the TNF inhibitor and non-TNF inhibitor groups respectively. Throughout the 5 years, 154 (55.4%) patients in the TNF inhibitor group did not change their treatment agent while 69 (24.8%), 24 (8.6%), and 1 (0.4%) switched once, twice, or 3 times or more, respectively. Thirty (10.8%) patients discontinued biologic usage. In the non-TNF inhibitor group, 3 (5.9%), 2 (3.9%), and 1 (2.0%) patients switched once, twice, or 3 times, respectively. Six (11.8%) patients discontinued biologic usage, and no change in treatment occurred in 39 (76.5%) patients. The mean number of biologic agent switches per patient in each group over 5 years was 0.43 times in the TNF inhibitor group and 0.20 times in the non-TNF inhibitor group, indicating that the number was significantly lower in the non-TNF inhibitor group (p=0.0032). Conclusions While the sample size was small and patient characteristics varied, it appears that non-TNF inhibitors are not inferior to TNF inhibitors as 1st line therapy biologics in terms of retention rate and number of switches to TNF inhibitors. Disclosure of Interest None declared