ANEMIA IN PATIENTS WITH RHEUMATOID ARTHRITIS TREATED WITH JAK INHIBITORS

Y. Takeuchi, M. Konishi, H. Hirabayashi, M. TokudaSanuki municipal hospital, Rheumatology, Kagawa, Japan  Background Recently, the safety of JAK inhibitors in the treatment of rheumatoid arthritis(RA) about malignancy and major adverse cardiac events has been highlighted , but there are still few reports on their effects on anemia. Filgotinib (FIL) is known to be a highly JAK1-selective agent with little effect on EPO-mediated JAK2 signaling . Objectives We investigated the effect of FIL on anemia in RA patients treated with JAK inhibitors at our hospital, comparing with other JAK inhibitors (non-FIL). Methods 73 patients who used 4 JAK inhibitors (filgotinib, tofacitinib, baricitinib, upadacitinib) after 2013 were divided into FIL group (16 patients) and non-FIL group (57 patients) respectively. Hemoglobin (Hb) trends at 3 and 6 months after the start of JAK inhibitors were investigated retrospectively. Subsequently, the investigation was performed with propensity score matching by age, gender, baseline Hb, CRP, s-Cre, presence of anemia treatments, presence of corticosterids/DMARDs, and history of previous bDMARDs/JAK inhibitor use. And, among the FIL group, we also examined whether there was a difference in Hb change depending on the history of JAK inhibitor use. Results Hb levels at the baseline were 10.5 g/dl in the FIL group and 11.6 g/dl in the non-FIL group, but there was no significant difference. The patients in the FIL group were significantly more likely to have used bDMARDs, other JAK inhibitors, and anemia treatments on starting FIL. Both at 3 and 6 months, although Hb levels were significantly increased in the FIL group (P<0.05), the anemia progressed over time in the non-FIL group despite exclusion of hemorrhagic anemia (Figures 1,2). The results after propensity score matching were also similar (P<0.05). There were no differences in CRP or RA disease activity at 0, 3, and 6 months. And then, compared to the FIL group with no history of JAK inhibitor use, the group that switched to FIL as a 2nd JAK inhibitor showed a significant Hb increase (P<0.05). Conclusion Compared to other JAK inhibitors, FIL did not reduce Hb levels and that could be maintained for a long time. In patients with anemia concerned with JAK inhibitors, switching to FIL is possible to make RA treatment safer and more successful. References FDA Drug Safety Communication issued on February 4, 2021. Traves PG, Murray B, Campigotto F, et al. JAK selectivity and the implications for clinical inhibition of pharmacodynamic cytokine signaling by filgotinib, upadacitinib, tofacitinib and baricitinib. Ann Rheum Dis. 2021; 80: 865-875. Figure 1. Image/graph: Figure 2. Image/graph: Acknowledgements: NIL. Disclosure of Interests None Declared. Keywords: Rheumatoid arthritis, Targeted synthetic drugs, Safety DOI: 10.1136/annrheumdis-2023-eular.1076Citation: , volume 82, supplement 1, year 2023, page 1440Session: Rheumatoid arthritis - non biologic treatment and small molecules (Publication only)