A study has shown that leflunomide (LEF) can be an effective alternative to methotrexate (MTX) in combination with rituximab (RTX) in the treatment of patients with rheumatoid arthritis (RA). RTX for rheumatoid arthritis is now mostly used in combination with MTX, which is a new option for the treatment of rheumatoid arthritis. However, many patients do not do well with MTX or cannot tolerate it. Is it possible to find an alternative to MTX in combination with RTX? LEF is a new type of immunosuppressant that inhibits the abnormal activation of lymphocytes and the resulting immune response by inhibiting dihydroorotic acid dehydrogenase and tyrosine kinase to reduce the ab initio synthesis of pyrimidines. Multicenter randomized double-blind controlled clinical studies have been conducted in thousands of patients with rheumatoid arthritis in China and abroad, and the results have demonstrated that this drug has a better effect than methotrexate in reducing bone erosion and joint protection within 1 year of administration. Recently, Javier Narváez et al. of the Barcelona Rheumatology Research Group in Spain conducted a study of 108 patients with rheumatoid arthritis.
Narváez et al. found, after 6 months of treatment in 108 patients with rheumatoid arthritis, that the efficacy of the LEF+RTX treatment group (32 patients) was similar to that of the MTX+RTX treatment group (45 patients), with an overall effectiveness rate of 77% for both DAS28 scores, which was better compared to RTX monotherapy (31 patients). The incidence of adverse events was similar in both groups at 9%, including mainly gastrointestinal symptoms, but there were no cases of withdrawal from the group due to serious adverse events. RTX induced B-cell lysis by binding to B-cell surface CD20, while LEF also inhibited B-cell proliferation, and the combination of the two produced a synergistic effect. In contrast, MTX cannot inhibit the autologous response of B-cell clones and cannot cope with the tolerance defect of B cells. Experts concluded that there was no significant difference between rituximab combined with methotrexate and rituximab alone. The investigators say that LEF can be an effective alternative to MTX in combination with RTX for the treatment of RA patients, and this study provides a new option for the treatment of RA patients.