AB0818 ADVERSE EVENTS UNDER B-CELL DIRECTED THERAPIES IN A LARGE SINGLE-CENTER COHORT OF PATIENTS WITH RHEUMATOID ARTHRITIS, SYSTEMIC LUPUS ERYTHEMATOSUS, ANCA-ASSOCIATED VASCULITIS AND RENAL DISEASES
Authors: J. G. Rademacher, V. Korendovych, P. Korsten
Journal: Annals of the Rheumatic Diseases (2021)

Background: The anti-CD20 antibody rituximab (RTX) is approved for the treatment of rheumatoid arthritis (RA) and ANCA-associated vasculitis (AAV). In addition, RTX is used in a wide range of autoimmune diseases. Belimumab (BEL) is an anti-BAFF antibody approved for the treatment of non-renal systemic lupus erythematosus (SLE) in Europe. These agents are generally well-tolerated but severe adverse events (AEs) can occur. The frequency of and factors associated with AEs are currently unknown. Objectives: To identify adverse events with the use of B-cell directed therapies in a large population of RA, AAV, and SLE. Methods: This is a single-center retrospective cohort study using routine clinical data over a ten-year period (2010-2020). We recorded epidemiological and clinical data of patients receiving either BEL or RTX. Data included age, gender, type of disease, number and efficacy of infusions, patient-years and concomitant treatment. Patient records were screened for AEs, such as infections, anaphylaxis, occurrence of malignant disease, laboratory abnormalities and immunoglobulin (Ig) deficiency. Between group comparisons were performed. Results: Database screening yielded 445 patients treated with RTX and 23 with BEL. After exclusion of patients with incomplete data, 425 RTX and 23 BEL patients were analyzed. Our preliminary analysis of a sample of 60 of these 448 patients (184 patient-years) resulted in 43 patients (72%) with RA, 8 patients with AAV (13%), 5 patients with a renal disease, and 4 patients with mixed connective tissue disease, as well 23 SLE patients. 46 (77%) were female. In RA, a median of 13 treatments of 1000 mg were administered, corresponding to 3.37 patient-years per patient. Primary non-response occurred in 2 patients, secondary non-response in 13 patients. For AAV, a median of 8.4 treatments were given (3.3 patient-years), no treatment failure was detected. SLE patients received a median of 15 treatments. 15 patients had infectious complications during treatment, 11 needed treatment. Herpes zoster infection occurred in 3 patients with RA. Three of the 8 patients with AAV had an infection requiring treatment. In SLE patients, only 2 developed infectious complications, and no Ig-deficiency occurred. Lymphopenia was the most common laboratory abnormality detected in 25 patients with RTX, 19 of whom had RA. Ig deficiency was common in RA, affecting 30% of patients. Deficiency of IgM and IgG was recognized in 5 patients each; 1 patient had low levels IgA. Neither the maintenance prednisolone dosage nor Ig deficiency were associated with risk for infection. However, lymphopenia appeared to be associated with risk for infection. Conclusion: Our preliminary data observe a 184 patient-year period. RTX and BEL were generally associated with few AEs. RA patients frequently had laboratory abnormalities (lymphopenia, Ig-deficiency) which did not necessarily translate to clinical events. Infections were more common in AAV, BEL was the best tolerated B-cell directed agent. Overall, our data are reassuring, but we suggest a more careful vigilance in AAV patients. Disclosure of Interests: Jan-Gerd Rademacher: None declared, Viktor Korendovych: None declared, PETER KORSTEN Speakers bureau: Abbvie, Sanofi Aventis, GSK, Chugai, Boehringer-Ingelheim, Novartis, Consultant of: Lilly, Gilead, Boehringer-Ingelheim, Novartis, GSK, Grant/research support from: GSK