Efficacy and safety of abatacept in patients with rheumatoid arthritis with previous malignancy

Background: Abatacept (ABT) is known to lower infection risk than other biologics and is effective and safe in elderly patients with rheumatoid arthritis (RA). However, there were inconsistent reports on the impact of ABT on malignancies which are more common in the elderly and strongly related to prognosis. Objectives: This study aimed to evaluate the efficacy and safety of ABT in patients with RA with previous malignancy in clinical practice. Design: A multicenter, retrospective study. Methods: Patients who received ABT for RA in two hospitals in Yokohama until May 2022 were included in this study. The patients were divided into two groups according to the presence or absence of a history of malignancy (no previous malignancy: NP group, previous malignancy: PM group). The collected parameters were compared between the groups using propensity score matching. Results: In this study, 312 patients were included, of whom 73 had previous malignancies when starting ABT. The age at ABT initiation was significantly higher in the PM group, the rate of methotrexate use was significantly lower in the PM group, and the Steinbrocker stage was significantly higher in the PM group. After matching these 3 factors, 68 patients were selected from each group. No significant differences in the ABT continuation rate, and malignancy incidence were observed between the two groups after ABT initiation. In addition to these factors, when matched for smoking history, interstitial lung disease, disease duration, sex, and inflammatory status, which are known risk factors for malignancy in RA, 40 patients were selected from each group. No significant differences in the ABT continuation rate, and malignancy incidence were observed between the two groups after ABT initiation. Conclusion: In our clinical practice, ABT was as effective and safe in patients with a history of malignancy as in those without.