THU0195 ULTRASOUND EVALUATION FOR MONITORING RESPONSE TO BARICITINIB IN RHEUMATOID ARTHRITIS PATIENTS AT EARLY STAGE AFTER TREATMENT

Abstract

Background: Baricitinib (bari) is approved for treating moderate-severe RA in many countries including Japan. Bari, an oral Janus kinase (JAK1)/JAK2 selective inhibitor, has shown the efficacy in patients with rheumatoid arthritis (RA) and in adequate response to conventional synthetic DMARDs in some clinical trials. Thanks to technological improvement in Ultrasound (US) equipment and the use of internationally approved scanning techniques and definitions for normal findings and pathology, US monitoring are widely used to assess inflammatory and structural lesions in daily clinic. Objectives: To monitor the short-term response to baricitinib therapy in bilateral wrist and finger joints of RA patients by US and to evaluate correlation between US findings and clinical assessments. Methods: We included 23 Japanese patients with RA who have inadequate response to csDMARDs or bDMARDs (biologics-naive 19 cases and biologics-experience 4 cases). Patients were scheduled to receive bari 4mg or 2mg once daily dose as monotherapy or in combination with other csDMARDs. They were allowed to be decreased predonisolone when their disease activity was improved. Clinical evaluation was performed blinded to the results of the US assessment that had been carried out on the same day. Swollen joint counts on 28 joints (SJC), tender joint counts on 28 joints (TJC) and Clinical Disease Activity index (CDAI) were registered for each patient. Each parameter was evaluated at baseline, after 1 month and 3 months. Four sonographers, experiences in musculoskeletal US, who were blinded to the clinical and laboratory data, performed the US examination. The US assessment and scanning technique included evaluation of synovial sites in 26 joints (wrist- radiocarpal, midcarpal, radiocarpal joints, 1 - 5 MCP joints and 1 - 5 PIP joints). Gray scale (GS) and power doppler (PD) were graded according to a 0 - 3 semi-quantitative score depending on their severity [1]. We calculated total scores for each patient in GS (GS score) and PD (PD score) differently. We compared the change of GS score and PD score. In addition, we evaluated the correlation between the changes in GS score or PD score and the variations in clinical evaluation items. Results: Patient’s backgrounds were provided in Table 1. All clinical parameters were significantly improved at each follow-up periods after treatment. Mean SJC, TJC and CDAI decreased from 7.52 ± 3.89, 8.26 ± 3.82 and 26.89 ± 9.48 at baseline to 1.52 ± 1.75, 1.82 ± 1.89 and 6.40 ± 5.17 at 1month and to 1.27 ± 1.39, 1.27 ± 1.38 and 3.99 ± 3.49 at 3 months respectively (Table 2). GS and PD score at each follow-up periods after treatment were also significantly improved. Mean GS and PD decreased from 8.11 ± 3.41 and 12.42 ± 4.45 at baseline to 3.63 ± 2.45 and 7.73 ± 4.70 at 1month and to 2.10 ± 1.49 and 4.21 ± 2.70 at 3 months respectively (Table 2). GS score significantly correlated with SJC (r= 0.586, p Conclusion: Baricitinib therapy had significantly improved disease activity of RA patients at early stage after the treatment. GS and PD score were also significantly improved and correlated with clinical parameters. These data confirm that the use of US evaluation is very useful method for evaluating the monitoring the response of treatment and feasible method complementary to clinical assessment for guiding the clinician in the appropriate therapeutic decision. Disclosure of Interests: None declared