Obinutuzumab treatment for membranous nephropathy: effectiveness and safety concerns during the COVID-19 pandemic.

Background: Obinutuzumab is a humanized and glycoengineered anti-CD20 monoclonal antibody that has been shown to induce more profound B-cell depletion than rituximab. The effectiveness and safety of obinutuzumab in the treatment of membranous nephropathy remain unclear.

Methods: This was a retrospective study conducted in Huashan Hospital, Fudan University between 1 December 2021 and 30 November 2023. Patients with membranous nephropathy were included to assess the effectiveness and safety of obinutuzumab and prevalence of severe pneumonia during the outbreak of COVID-19 in China.

Results: Eighteen patients were included in the study assessing the effectiveness of obinutuzumab. After a 12-month follow-up, 14 patients (78%) achieved remission, with six (33%) achieving complete remission and eight (44%) achieving partial remission. Among the 18 obinutuzumab-treated patients contracting COVID-19 for the first time, six (33%) developed severe pneumonia, and one died. By contrast, two of the 37 patients receiving glucocorticoids combined with cyclophosphamide, and none of the 44 patients on calcineurin inhibitors or the 46 patients on rituximab developed severe pneumonia. However, compared to patients receiving rituximab or glucocorticoids plus cyclophosphamide, the obinutuzumab-treated patients had a longer duration of membranous nephropathy and immunosuppressive therapy. Therefore, cardinal matching was employed to balance these baseline characteristics. Owing to small sample size for each regimen, patients receiving all the three non-obinutuzumab immunosuppressive regimens were grouped as a control cohort. After matching for age, gender, remission status, duration of membranous nephropathy, duration of immunosuppressive therapy, and ongoing immunosuppression, the obinutuzumab-treated patients still had a significantly higher incidence of severe pneumonia compared to those on other regimens (P = .019).

Conclusion: Obinutuzumab was an effective treatment option for patients with membranous nephropathy. On the other hand, it was associated with a higher incidence of severe pneumonia following COVID-19 infection compared to other immunosuppressive regimens.