POS0860 EFFICACY AND SAFETY OF TWO COURSES OF RITUXIMAB BIOSIMILAR ACELLBIA IN PATIENTS WITH INTERSTITIAL LUNG DISEASE ASSOCIATED WITH SYSTEMIC SCLEROSIS: A PROSPECTIVE OBSERVATIONAL STUDY

Background:Interstitial lung disease associated with systemic sclerosis (ILD-SSc) is a frequent manifestation of the disease, impairing the quality of life and the prognosis of the disease. The efficacy of rituximab (RTX) in patients (pts) with ILD-SSC have been shown [1]. The ‘‘biosimilar’’ versions of RTX might reduce the cost of therapy and increase pts accessibility to this treatment option. The RTX biosimilar Acellbia (ACB), “BIOCAD”, has received approval in Russian Federation in 2014 for all indications held by reference RTX.Objectives:to investigate the efficacy and safety of ACB in naive to biological therapy pts with ILD-SSc during at least 12 month of follow-up.Methods:Twenty pts were included in prospective observational study. The pts were aged 49,7 (s.d.14) years, 14 (70%) were females, mean disease duration was 3,5±2,7years, with diffuse subset in 11 (55%), 13 (65%) were anti-topoisomerase positive, all pts has NSIP-pattern by HRCT. All pts were naive to ACB, received glucocorticoids in low doses, 10 (50%) pts were previously treated with immunosuppressants and 4(20%) of them continued to take mycophenolate mofetil as a concomitant therapy. Pts received two courses of ABC with the same scheme: 1 g repeated 1 week apart (4 g ACB in total). An assessment of basic measurements was obtained at baseline (Point 0), before the second course (after 7,2±1,7 mo, Point 1) and at the end of follow-up (13,4±1,6 mo, Point 2). The results are presented in the form of mean values and standard deviations.Results:We observed a gradual improvement in the main parameters from Point 0 to Point 2 (table). Importantly, that at Point 1 there were no differences in most parameters, except for Rodnan skin score (mRSS) and the absolute number of B-lymphocytes (B-lymph), but at Point 2 there were significant differences between most basic outcome measures.Table 1.Follow-up data of ACB treatment in ILD-SSC ptsParametersPoint 0(n=20)Point 1(n=20)Point 2(n=18)#P 1-2P 1-3mRSS12,75±11,18,25±7,726,16±5,650,0020,002FVC*, % pred89,1±18,292,31±19,2198,26±16,13NS0,0002DLCO**, % pred56,67±15,758,11±17,7161,86±17,16NS0,019SHAQ1,13±0,6280,98±0,6780,61±0,495NS0,00001IgG, g/l12,61±2,34811,5±1,6110,19±2,18NS0,002a-Topo-1, unit/ml109,68±86,9296,46±81,7272,46±69,46NS0,004B-lymph, absolute count0,329±0,340,0016±0,0030,00189±0,0030,00040,001Glucocorticoids, mg/day11,0±2,710,75±2,09,4±2,3NS0,03*FVC - forced vital capacity % predicted, **DLCO - diffusion capacity for carbon monoxide % predicted.# Of the 20 patients who received the second course, 2 (10%) dropped out the follow-up due to pregnancy (1) and lung cancer (1).The frequency and spectrum of adverse events (AE) corresponds to the known in the treatment of RTX, most AEs were classified as mild ones.There were 11 (55%) of AE in 9 (45 %) pts. Infections were observed in 7 (35%) pts: 4 cases of acute respiratory tract infections, 2 cases of positivity in interferon-gamma release assayand one case each of otitis, cystitis, cholecystitis (9 AE in total). One pts developed low limb vein thrombosis and one - lung cancer. There were no infusion-related reactions.Conclusion:The data from this prospective pilot study showed the effectiveness of the АСB in ILD-SSc. The clinical effect of АСB arises gradually and the baseline outcome measures reliably improve by the end of the first year. Our study have demonstrated a well-tolerated safety profile. We believe that ACB can be prescribed at SSc-ILD as a first-line drug and/or in the form of monotherapy.References:[1]Erre G.L., et.al. Efficacy, Safety, and Tolerability of Treatments for Systemic Sclerosis-Related Interstitial Lung Disease: A Systematic Review and Network Meta-Analysis. J.Clin.Med.2020,9,2560;doi:10.3390/jcm90825-60.Disclosure of Interests:None declared