COMPARATIVE ANALYSIS OF EARLY AND LATE ADMINISTRATION OF THE RITUXIMAB BIOSIMILAR BCD020 FOR SYSTEMIC LUPUS ERYTHEMATOSUS IN CHILDREN. RESULTS OF A SINGLE-CENTER RETROSPECTIVE COHORT STUDY

Juvenile systemic lupus erythematosus (jSLE) is a severe life-threatening disease with an immunoinflammatory pathogenesis and possible involvement of several organs or organ systems, both sequentially and simultaneously. Early initiation of biological therapy may improve disease outcomes. The purpose of this research was to evaluate the benefits of early initiation of genetically engineered biological therapy for jSLE with the Rituximab biosimilar BCD020. Materials and methods used: a single-center retrospective cohort study performed at the Saint Petersburg State Pediatric Medical University (Saint Petersburg, Russia) in 2012-2022 that included information on 36 patients with early Rituximab prescription (ERP; within less than 6 months from the jSLE diagnosis) and late Rituximab prescription (LRP; after over one year). The main characteristics of the disease were compared at the onset, at the time of initiation of Rituximab therapy and at 12 months after that. Results: the main baseline differences between the groups were statistically significantly higher disease activity according to the SLEDAI scale (p=0.003) and a higher incidence of macrophage activation syndrome (p=0.096), a higher average daily dose of glucocorticosteroids (GCS) in the ERP group (p=0.027). At the end of the study there were no statistically significant differences in the main outcomes of SLE between the compared groups. The main advantages of ERP were a statistically significantly shorter time to achieve a low daily dose of GCS (<0.2 mg/kg) - 1.2 (0.9; 1.4) years compared to 2.8 (2.3; 4 .0) years (p<0.001) and a higher likelihood of achieving a low dose of corticosteroids (RR=57.8 [95% CI: 7.2; 463.2], p<0.001) and achieving remission (SLEDAI=0); RR=37.6 [95% CI: 4.45; 333.3], p<0.001). During the research there were no statistically significant differences in the incidence of adverse events, including severe adverse events, between the compared groups of patients. Conclusion: ERP makes it possible to improve the control over the activity of jSLE and minimize the volume of GCS drugs with similar treatment outcomes and safety profile. Further research is required in order to determine the indications for biological therapy for jSLE.