ADMINISTRATION OF BELIMUMAB IN EARLY ACTIVE LUPUS PATIENTS HINDERS ACCRUAL OF EULAR/ACR CRITERIA WITHIN THE FIRST 12 MONTHS OF TREATMENT

Background: Addition of biologic drugs to standard of care (SoC) in systemic lupus erythematosus (SLE) is advised in refractory patients. Evidence is needed on the effectiveness of early biologic use in influencing SLE course. Objectives: To assess the effect of belimumab administration on disease progression in early active lupus patients. Methods: We performed a multicentric observational study on patients with early SLE receiving either belimumab or SoC alone and compared the rate of EULAR/ACR 2019 criteria [1] accrual between the two groups as a measure of lupus progression over time. Patients were defined as early active if they were diagnosed within 12 months from treatment initiation and displayed up to two EULAR/ACR clinical criteria, excluding major organ involvement, with active serology (i.e. positive anti-dsDNA antibodies and/or decreased serum complement). Clinical, demographic and serological data were collected in an anonymized fashion at baseline and at 3, 6, and 12 months. Kaplan-Meier curves with log-rank comparison were used to assess criteria accrual throughout the first 12 month of follow-up. Results: We included 57 early active SLE patients, 24 (42.1%) receiving SoC alone and 33 (57.9%) receiving add on belimumab to SoC and followed up for at least 12 months from baseline. The groups were comparable in terms of age, gender, disease duration, background immunosuppression and overall disease activity at baseline. Patients doomed to early belimumab displayed higher mean SLICC and prednisone daily dosage (Table 1 ). Overall, 8.7 events/100-patients years occurred in our cohort. Twenty-five percent of patients on SoC versus 3.2% of patients on early belimumab accrued at least one EULAR/ACR criterion throughout the follow-up (p=0.035). Patients on SoC displayed development of skin rash (2 cases), arthritis (1 case), lupus nephritis (1 case), while one case of pericarditis occurred in the belimumab group. Criteria-free survival was significantly longer in patients receiving belimumab early as compared to those receiving SoC alone ( log-rank 5.78, p=0.016 ) Figure 1 . Mean time-to-event (months) was shorter in patients on SoC alone (10.3± 3.33 vs. 11.8±1.07, p=0.027). Conclusion: Timely use of belimumab in patients with early active SLE can significantly delay disease progression, potentially preventing development of severe manifestations. REFERENCES: [1] Aringer M, et al. 2019 European League Against Rheumatism/American College of Rheumatology Classification Criteria for Systemic Lupus Erythematosus. Arthritis Rheumatol 2019;71:1400-1412. doi: 10.1002/art.40930. Table 1. Baseline clinical and demographic features of early SLE patients Belimumab SoC P Age 34.05±11.60 38.65±11.12 0.141 Gender, F (%) 29 (87.9) 23 (95.8) 0.385 HCQ n (%) 30 (90.9) 17 (70.8) 0.077 IS n (%) 26 (78.8) 21 (87.5) 0.494 Prednisone mg/d 8.75±6.67 5.00±10.61 0.054 Anti-dsDNA titers (kU/L) 201.04±282.95 88.91±46.86 0.020 C3 mg/dl 79.54±27.41 82.48±23.91 0.348 C4 mg/dl 12.00±5.12 10.77±3.53 0.180 cSLEDAI-2K 5.42±1.76 5.75±1.33 0.227 SLICC-DI 0.12±0.42 0.00±0.00 0.052 Continuous variables expressed as mean±SD. HCQ, hydroxycholoroquine; IS, immunosuppressants; cSLEDAI-2K, clinical SLE-activity index 2000; SLICC-DI, SLICC damage index Figure 1. Kaplan-Meier curves depicting criteria-free survival in patient groups Acknowledgements: NIL. Disclosure of Interests: Mariele Gatto GSK, AstraZeneca, Janssen, Matilde Caria: None declared, Claudio Cruciani: None declared, Pietro Francesco Gavino Pilo: None declared, Elisa Bellis BMS, Denise Donzella Janssen, Roberto Depascale: None declared, Daniela Rossi: None declared, Dario Roccatello: None declared, Andrea Doria GSK, AstraZeneca, Pfizer, Celgene, Eli Lilly, BMS, Roche, Annamaria Iagnocco Abbvie, Alfasigma, BMS, Celgene, Celltrion, Eli Lilly, Galapagos, Gilead, Janssen, MSD, Novartis, Pfizer, Sanofy Genzyme, SOBI, Abbvie, Pfizer, Novartis, Savino Sciascia: None declared. DOI: 10.1136/annrheumdis-2024-eular.4386 Keywords: Real-world evidence, Best practices, Biological DMARD, Quality of care Citation: , volume 83, supplement 1, year 2024, page 1003Session: Systemic lupus erythematosus (Poster View)

Real-world evidence, Best practices, Biological DMARD, Quality of care