OP0250 BREAKTHROUGH INFECTIONS AND PREDICTING SEVERE COVID OUTCOMES DURING RITUXIMAB THERAPY IN AUTOIMMUNE RHEUMATIC DISEASES

Background As rituximab (RTX) is a B-cell depleting agent, there are concerns regarding its safety during the COVID pandemic. Data from registries pre-vaccination period reported increased risk of poor outcomes in RTX-treated patients vs TNFi. However, registry data could be limited by reporting bias determining true incidence. There also on breakthrough infections following vaccination. Objectives To assess incidence and predictors severe autoimmune rheumatic diseases (ARDs) with view to establishing treatment algorithm for safe RTX administration. Methods An observational cohort study was undertaken first consecutive 300 ARD single centre between index date 01/09/2019 (i.e. 6 months prior pandemic) 31/01/2022. Only PCR positive cases were included. categorised as Mild not hospitalised) or Moderate/Severe hospitalised requiring at least oxygenation death). Predictors moderate/severe analysed using Cox-regression proportional hazard. Results Mean (SD) 59 (14) years, 226/300 (75%) female 254 (85%) Caucasians. The diagnoses RA=212 (71%), SLE=33 (11%), AAV=26 (9%), Sjogren=9 (3%), IIM=8 (3%) others=12 (4%). Therapy included concomitant DMARDs = 205 (68%) oral prednisolone 84 (28%). Median (range) no. previous courses 4 (0-19). 534 administered. Of 294 available vaccine data, 17 (6%) unvaccinated, (1%) had dose, 47 (16%) double-vaccinated, 217 (74%) triple-vaccinated 9 quadruple-vaccinated. those who vaccinated, 11% given within 12 weeks post-RTX, 15% 26 74% >26 post-RTX. rate overall 11.2/100 PYs 2.6/100 respectively. Vaccinated lower infection (2.6/100 PYs) unvaccinated (18.6/100 [Table 1]. Over 650.7 PY follow-up, 17/300 (5.7%) including 2 deaths. Factors associated time-to-infection imputed multivariable analysis number comorbidities [HR 1.46 (95% CI 1.05-2.04)] low IgG (<6g/L) [6.15 (1.95-19.41)]. A history vaccination reduced 0.13 (0.03-0.51)]. Demographics prednisolone, RTX- vaccine-associated factors (e.g. time vaccine, mode, peripheral depletion) predictive. Table 1. Incidence Pre-Vaccination Programme Post-Vaccination Overall Follow-up 3.3/100 Non-vaccinated 37.7/100 73 years] 18.6/100 2.1/100 Non-Vaccinated 15.1/100 Conclusion this comparable pre-pandemic trials RA. high uptake our effective preventing despite termination national shielding programme March 2021 spread Delta Omicron variants. Individualised risk–benefit assessment should comorbidities, when scheduling therapy. References None Acknowledgements This research funded/supported Wellcome Trust Institutional Strategic Support Fund MYMY (204825/Z/16/Z), National Institute Health Research (NIHR) Doctoral Fellowship (DRF-2014-07-155) NIHR Clinician Scientist EMV (CS-2013-13-032). PE Versus Arthritis Professor Rheumatology. article/paper/report presents independent Leeds Biomedical Centre. views expressed author(s) necessarily Department Social Care. Disclosure Interests Md Yuzaiful Yusof Consultant of: Aurinia Pharmaceuticals, Jack Arnold: declared, Benazir Saleem: Claire Vandevelde: Shouvik Dass: Sinisa Savic Speakers bureau: Novartis, Swedish Orphan Biovitrum (SOBI) Sire, Grant/research support from: Biovitrum, Octapharma CSL Behring, Edward Vital Roche, GSK AstraZeneca, Paul Emery BMS, Abbott, Pfizer, MSD, Roche UCB, MSD Roche.