SAT0171 RITUXIMAB IN SYSTEMIC AUTOIMMUNE RHEUMATIC DISEASES: ONE CENTER EXPERIENCE OF TREATMENT 515 PATIENTS
Authors: E. Nasonov, T. Beketova, L. P. Ananyeva, S. Solovyev, V. Vasiliev, O. Koneva, O. Desinova, S. Palshina, E. Sokol, E. Nikollaeva
Journal: Annals of the Rheumatic Diseases (2020)

Background: B cells have important functions in the pathogenesis of systemic autoimmune rheumatic diseases (SARDs). Objectives: The purpose of the research was to study the therapeutic option of Rituximab (RTM), a chimeric anti-CD20 antibody, in SARDs such as ANCA-associated systemic vasculitis (AAV), cryoglobulinemic vasculitis (СV), systemic lupus erythematosus (SLE), systemic sclerosis (SS), primary Sjögren syndrome (pSS) and IgG4-related disease (IgG4-RD). Methods: We present data on efficacy and safety of RTM in 515 patients (pts) with SARDs. 103 pts had AAV (58- granulomatosis with polyangiitis, GPA; 35- microscopic polyangiitis, MPA and 10- eosinophilic granulomatosis with polyangiitis, EGPA), 21 pts had CV, 167- SLE, 90- SS, 100- pSS, 34- IgG4-RD. Characteristics of pts and results of RTM treatment are present in Table. Mean follow-up duration after initiation of RTM was 25- 58 months. Results: The average cumulative RTM dose in all groups exceeded 2.4 g, 71% of pts received repeated RTM courses (0.5-1.0 g) every 4 – 12 months. Complete (good) clinical response was achieved in 70-93% pts, except for the SLE (49%- complete response, 32- incomplete and 19%- no response). Usage of repeated RTM courses increased the clinical efficacy and reduced the risk of recurrence. Despite the fact that the study population included a high percentage of pts with severe or refractory SARDs, total mortality rate was about 6% during the follow-up period, highest in CV and AAV (14-11%). In AAV and SLE infections constitute a significant proportion of serious adverse reactions (10-11%). Late-onset neutropenia was only in pts with AAV (12%) and SLE (3%). Conclusion: Treatment with RTM was highly effective in SARDs. In certain SARDs RTM safety profile of should be considered during treatment planning. Further studies of the targeted anti-B-cell therapy, including RTM efficacy and safety in SARDs, clarification of the indications and optimal RTM regimens are needed. Table. Parameters АAV CV SLE SS pSS IgG4-RD GPA, MPA EGPA N pts 93 10 21 167 90 100 34 Age, years 41 (16-67) 50 (24-71) 53,6 + 29 41 (18-52) 47 (17-71) 42 + 12,2 47,4 + 15,9 Percentage of females 56% 90% 52% 92% 75% 97% 60% Duration of disease, months* 14 (1-288) 11 (1-180) 72 (3-96) 18 (2-47) 70 (7-264) 90 (36-168) 24 (6-60) Cumulative RTM dose, g* 3 (0,5-8) 3 (1,5-5,5) 4,7 + 3,8 2,4 (1,8±0,8) 2,9 (0,5-6) 5,5 + 1,5 4 + 1,5 Follow-up duration after the first RTM course, month* 37 (1–96) 36 (14-94) 52 (6-108) 38 (12-67) 27 (12-42) 58 (24-96) 25 (3-60) Clinical response, % Complete (good) 93% 90% 71% 49% 70% 92,5% 77% Incomplete response 6% 10% 29% 32% 24% 6,5% 23% No response 1% 0% - 19% 6% 1% - Relapse 8% 30% - - nd - - Glucocorticoids dose, mg/day*: Before RTM After RTM 30(5–60) 5(0-10) 20(7,5-50) 7,5(5-10) 4,4(0-24) 1,5(0-4) 28(15-40) 7,5(5-15) 12(0-25) 9(0-15) 7,5(0-40) 1,25 10(2,5-40) 0,5 Immunosuppressants % pts before RTM 72% 90% 38% 65% 43% 44% 40% % pts after RTM 43% 70% 5% 46% 50% 8% 10% Infusion-related reactions, 9% 20% 24% 4% 2% 10% 3% including severe - 10% - 0,6% 1% 1% - Pts with serious adverse reactions, 26% 40% 5% 14% 2% 5% 3% including: infections, 11% 10% - 10% 2% 5% 3% neutropenia 10% 20% - 3% - - - Deceased pts during the follow-up 11% - 14% 5% 6% 2% - *Data are provided in the following format: median &amp; min-max range in the brackets Disclosure of Interests: None declared