THE COMPARATIVE RISK OF HOSPITALIZED INFECTION IN RHEUMATOID ARTHRITIS PATIENTS INITIATING ABATACEPT OR TUMOR NECROSIS FACTOR INHIBITOR TREATMENT: A NATIONWIDE, POPULATION-BASED COHORT STUDY

Background: Few population-based studies have compared the risks of hospitalized infection between patients with rheumatoid arthritis (RA) starting abatacept or TNFi treament. Objectives: The study aimed to assess the relative risk of hospitalized infection in RA patients initiating TNFi treatment compared to those starting abatacept therapy. Methods: The data source of this study was the 2003–2017 claims data from the Taiwanese National Health Insurance Research Database. First, we identified all RA patients who started their first biologic disease-modifying antirheumatic drug (DMARD)/targted-synthetic (ts) DMARD therapy. The index date was the first date of bDMARD/tsDMARD prescription. Subjects were followed up till the date of first hospitalization due to infection, 90 days after the last date of bDMARD/tsDMARD prescription, withdrawl from national health insurance or death, whichever came first. We calculated the incidences of hospitalized infection. We further matched abatacept users with TNFi users with a 1:4 ratio for age, sex and disease duration. A Cox regression analysis was used to examine the associations of covariates with the risk of hospitalized infection shown as hazard ratios (HRs) with 95% confidence interval (CIs). Covariates included age, sex, Charlson comorbidity index, a history of hospitaized infection within 5 years before the index date, prior RA-related medications within 6 months before the index date and concomitant RA-related medications. The relative risk of hospitalized infection in abatacept users compared to TNFi users were estimated after adjusting for covariates with a p-value Results: We identified 10,780 RA patiets who started their first bDMARD/tsDMARD treatment. Of them, 8,492 patients received TNFi treatment (etanercept n=4,390; adalimumab n=3,058; golimumab n=1,125), 614 patients were treated with tocilizumab, 278 patients were treated wtih rituximab, 737 patients were treated with abatacept, and 659 patients were treated wtih tofacitinib. The incidence rates (IRs) of hospitalized infection in patients treated with TNFi, tocilizumab, rituximab, abatacept and tofacitinib were 351, 407, 2,692, 260 and 0 per 105 years respectively. After matching (1:4) for age, sex and disease duration, we compared the risks of hospitalized infection between 728 abatacept users and 2,912 TNFi users. The IRs of hospitalized infection in patients treated with abatacept, TNFi, etanercept, adalimumab and golimumab were 262, 434, 331, 739 and 0 per 105 years respectivcely. After adjusting potential confounders, use of TNFi was not asssociated with a greater risk of hospitalized infection compared with abatacept use (HR, 2.14; 95% CI, 0.74–6.13; p = 0.159). However, the risk of hospitalized infection was higher in adalimumab users compared with abatacept users (HR, 3.24; 95% CI, 1.09–9.62; p = 0.035). Conclusion: This nationwide, population-based, matched cohort study showed that among bDMARD/tsDMARD naive RA patients, use of adalimumab, but not etanercept or golimumab, was associated with a greater risk of hospitalized infection compared with the risk associated with abatacept use. References: [1]Yun H, et al. 2016. Comparative Risk of Hospitalized Infection Associated With Biologic Agents in Rheumatoid Arthritis Patients Enrolled in Medicare. Arthritis Rheumatol 68:56-66 Disclosure of Interests: Hsin-Hua Chen: None declared, Ching-Heng Lin: None declared, Yi-Hsing Chen Grant/research support from: Taiwan Ministry of Science and Technology, Taiwan Department of Health, Taichung Veterans General Hospital, National Yang-Ming University, GSK, Pfizer, BMS., Consultant of: Pfizer, Novartis, Abbvie, Johnson \u0026 Johnson, BMS, Roche, Lilly, GSK, Astra\u0026 Zeneca, Sanofi, MSD, Guigai, Astellas, Inova Diagnostics, UCB, Agnitio Science Technology, United Biopharma, Thermo Fisher, Gilead., Paid instructor for: Pfizer, Novartis, Johnson \u0026 Johnson, Roche, Lilly, Astra\u0026 Zeneca, Sanofi, Astellas, Agnitio Science Technology, United Biopharma., Speakers bureau: Pfizer, Novartis, Abbvie, Johnson \u0026 Johnson, BMS, Roche, Lilly, GSK, Astra\u0026 Zeneca, Sanofi, MSD, Guigai, Astellas, Inova Diagnostics, UCB, Agnitio Science Technology, United Biopharma, Thermo Fisher, Gilead., Yi-Ming Chen: None declared