Background Data on the efficacy and safety of biological therapies for Rheumatoid Arthritis (RA) that come from Patient Registries present the results of clinical practice all over the world. In terms of efficacy, treatment persistence in RA is largely related to reaching the therapeutic target, i.e. remission or low disease activity.
Objectives To measure drug persistence with tumor necrosis factor alpha (TNF) antagonists and anti CD20 monoclonal antibody, among RA patients in Romania, as well as identify/determine additional factors that could influence it.
Methods Population-based cohort study carried out with RA patients in Romania. Data was gathered from the Romanian Registry of Rheumatic Diseases. The study cohort included RA patients who initiated the first course of a TNF antagonist or anti CD20 monoclonal antibody, anytime between 2004 and 2015. Persistence was measured as the time period during which the drug had been administered to a patient. Drug discontinuation was defined as drug treatment being interrupted due to adverse events, primary or secondary non-responder, or switching to another molecule. The influence of any other factors on persistence used T test and persistence was estimated using survival analysis.
Results The study cohort included 4,395 RA patients, mean age 59.55 yrs, 85.3% women, mean RA duration 14.37 yrs, treated with etanercept (29.7%), adalimumab (23.5%), infliximab (original 7.1%, biosimilars 0.7%), rituximab (38.9%); 23.1% used steroids (19.8% with <7.5mg dayli); mean current DAS28 score 3.08 (±1.20) and mean SDAI 3.62 ((±7.39). The persistence estimated in weeks (95% confidence interval) with infliximab was 330.8 (303.8–357.8), with rituximab it was 301.0 (262.2–339.8), with etanercept it was 240.6 (232.7–248.4) and with adalimumab it was 200.4 (191.0–209.9). There was a poor positive correlation between general persistence and RA duration (r=0.2, p<0.001) and a negative association with DAS28 (r= - 0.3, p<0.001). The use of methotrexate resulted in longer persistence (170.5±139.8) compared to other csDMARDs (152.0±120.2), p<0.001. Using steroids in dosages less than 7.5mg/day resulted in a significantly longer persistence compared to larger doses (131.2±121.3 vs 100.1±110.7), p<0.005. Patients being in remission or LDA maintained the biologics significantly longer than those with MDA or HAD (190.9±139.0 vs 121.1±107.8), p<0.001. All other factors that were analysed (age, sex, residency, education, work status, disease characteristics) had no significant effect on drug persistence. Adverse events, primary non-responders, and secondary non-responders were comparable among these molecules.
Conclusions Longer persistence was observed with infliximab, followed by rituximab, etanercept, and adalimumab in RA patients in Romania, for more than 10 years of biologics use. Reaching the state of remission or LDA, as well as low steroids regimens and long-standing disease seem to positively correlate with drug persistence.
Disclosure of Interest None declared