A retrospective study of the efficacy and safety of rituximab biosimilar for the treatment of membranous nephropathy

BACKGROUND: Rituximab (RTX) is a monoclonal antibody that targets CD20 and is recommended by the KDIGO guidelines as a first-line treatment for membranous nephropathy (MN). The RTX biosimilar (HLX01) was the first biosimilar licensed in China in 2019. However, its efficacy and safety for MN treatment remain unclear. This study aimed to evaluate the performance of the RTX biosimilar for MN in a real-world setting. METHODS: In this study, the medical records of 201 MN inpatients treated with high-dose RTX biosimilar and followed up for one year from January 2020 to December 2022 at PUMCH were retrospectively collected. Efficacy was evaluated in accordance with the KDIGO guidelines. Adverse reactions recorded in medical records during or after infusion were collected. RESULTS: During the one-year follow-up period, the overall remission rate of high-dose RTX biosimilar treatment for MN was 75.12% (151/201), with 53 patients achieving complete remission and 98 patients reaching partial remission. The median time to remission was 6 months. Among patients who achieved remission, the relapse rate was 7.95% (12/151), among whom 7 patients achieved remission again after readministration. The remission rate was 78.79% (52/66) for treatment-naïve patients and 73.33% (99/135) for treated patients (P = 0.401). Adverse events included pruritus, flushing, hypotension, fever, rash, oropharyngeal discomfort, chest distress, eyelid edema, nausea and vomiting, and nasal congestion or rhinorrhea, with an overall incidence of 30.85% (62/201). CONCLUSIONS: Rituximab biosimilar has acceptable efficacy and safety in patients with MN, and their outcomes are similar to those of innovator RTX products reported in the literature. Thus, it may be used as an alternative to the innovator RTX as a first-line treatment for MN.