AB1165 FLUORESCENCE OPTICAL IMAGING XIRALITE® IS HELPFUL IN THE DECISION FOR RITUXIMAB RE-THERAPY IN PATIENTS WITH RHEUMATOID ARTHRITIS
Authors: Sarah Ohrndorf, Lisa Ridha, Anne-Marie Glimm, Gerd Rüdiger Burmester, Gabriela Schmittat, Marina Backhaus, Jens Klotsche
Journal: Annals of the Rheumatic Diseases (2019)

<h3>Background</h3> Rituximab (RTX) is an effective and well-tolerated therapeutic option in rheumatoid arthritis (RA) patients with insufficient response to TNFα inhibitors. However, the exact time point of RTX re-therapy often varies and objective parameters (e.g. imaging, such as MRI and/or musculoskeletal ultrasound [US]) are not yet included in the RA treatment strategy [1]. <h3>Objectives</h3> The aim of this study was to evaluate the ability of the fluorescence optical imaging Xiralite® (FOI) to predict RTX re-therapy in RA patients - in comparison to clinical, laboratory and US. <h3>Methods</h3> In this study, n=31 patients with established RA were included and prospectively followed over one year by DAS28, patient's global VAS (0-100 mm), CRP/ESR, US7 score (for synovitis and tenosynovitis in greyscale and power Doppler of the clinically dominant hand/foot; [2]), and by FOI (phases 1-3 and PrimaVistaMode [PVM]) at baseline (before RTX), and after 3,6, and 12 months. The need for RTX re-therapy was defined according to DAS28 response criteria by EULAR [3]. <h3>Results</h3> Of the included 31 patients (female 77.4%, mean age 60.1±11.4, mean disease duration 14.9±7.1 years), n=14 (45.2%) received RTX re-therapy within 12 months: n=3 after 6months (mths), n=4 after 7mths, n=5 after 9mths, and n=2 after 10mths. In the group with RTX re-therapy, FOI in PVM mode was the only parameter that presented significant increase (beta 0.40, CI 0.08-0.71; p=0.013) – compared to the group without re-therapy. In the prediction model via receiver operating characteristic (ROC) analysis, FOI in PVM reached the highest values of all imaging parameters (phases 1-3, US) at baseline for the prediction of re-therapy over one year with an area under the curve (AUC) of 0.64 (OR 0.9, CI 0.79-1.03), however, without significance (p=0.117). Patient's VAS and CRP had similar predictive power with AUC of 0.66 each (each p=ns). <h3>Conclusion</h3> The FOI Xiralite® in PVM is able to discriminate between groups with and without need for RTX re-therapy better than other included imaging parameters. It is able to predict the need for RTX re-therapy with comparable predictive power to patient's VAS and CRP. At the same time, FOI is a more objective tool, while patient's VAS and CRP can also depend on other influence (i.e. psychological, infectious) factors. Left image above shows FOI in PVM of both hands at baseline (before RTX). Right image above shows FOI in PVM of the same patient at 3months follow-up. Left image below shows FOI in PVM of the same patient at 6months follow-up. Right image below shows FOI in PVM of the same patient at 12months follow-up. This patient received re-therapy with RTX after 9 months <h3>Legend</h3> FOI: fluorescence optical imaging; PVM: PrimaVista Mode; RTX: rituximab <h3>References</h3> [1] Smolen JS, Landewé R, Bijlsma J, et al. EULAR recommendations for the management of rheumatoid arthritis with synthetic and biological disease-modifying antirheumatic drugs: 2016 update. Ann Rheum Dis. 2017 Jun;76(6):960-977. [2] Backhaus M, Ohrndorf S, Kellner H, et al. Evaluation of a novel 7-joint ultrasound score in daily rheumatologic practice: a pilot project. Arthritis Rheum. 2009;61(9):1194-201. [3] https://www.das-score.nl/das28/en/difference-between-the-das-and-das28/importance-of-das28-and-tight-control/eular-response-criteria.html <h3>Acknowledgement</h3> This study was supported by the Bundesministerium für Bildung und Forschung (BMBF) project "ArthroMark", subproject no. 7. <h3>Disclosure of Interests</h3> Sarah Ohrndorf: None declared, Lisa Ridha : None declared, Anne-Marie Glimm: None declared, Gerd Rüdiger Burmester Consultant for: Roche, Sanofi-Genzyme, Speakers bureau: Roche, Sanofi-Genzyme, Gabriela Schmittat: None declared, Marina Backhaus: None declared, Jens Klotsche: None declared