Obinutuzumab in Refractory Membranous Nephropathy: A Case Series.

RATIONALE & OBJECTIVE: Membranous nephropathy (MN), recognized as an autoimmune kidney disease, responds well to anti-CD20 monoclonal antibodies. Obinutuzumab, a type Ⅱ humanized anti-CD20 and immunoglobulin G1 Fc-optimized monoclonal antibody, when compared with rituximab, has demonstrated superior efficacy in B-cell leukemia and lymphoma, especially in rituximab-resistant cases. However, the efficacy and safety of obinutuzumab in MN remain unclear.

STUDY DESIGN

A case series study.

SETTING & PARTICIPANTS: A total of 18 patients were diagnosed with MN and had received obinutuzumab at our center without secondary MN, undergoing dialysis, having a history of kidney transplantation, or infections requiring treatment.

EXPOSURE

Obinutuzumab treatment.

OUTCOMES

Primary outcomes included remission rate, time to first remission, and first relapse-free survival time during the follow-up period.

ANALYTICAL APPROACH

Survival analysis was performed with Cox proportional hazards models, log-rank test, and Kaplan-Meier survival analysis.

RESULTS

Patients with MN (median age of 52.5 years, 83.3% males) received an average dose of 2.1 ± 0.8 g of obinutuzumab during a median follow-up period of 13.6 months. During the follow-up, 17 patients (94.4%) achieved remission, with 12 patients (66.7%) achieving partial remission, and 5 patients (27.8%) achieving complete remission. The median time to first remission and first relapse-free survival time was 2.7 (1.0-6.1) months and 9.8 (2.6-11.2) months, respectively. Of 12 patients with previous rituximab treatment, all achieved remission successfully, with 8 (66.7%) achieving partial remission and 4 (33.3%) achieving complete remission. Adverse events were mostly mild, and no severe treatment-related adverse events were observed.

LIMITATIONS

Limited or missing data; risks of selection bias; or recall bias; underestimated first relapse-free survival time because of a limited follow-up period; unmonitored counts of CD19 B-cells and other lymphocyte subsets.

CONCLUSIONS

Obinutuzumab demonstrated promising efficacy and safety in inducing remission in MN, particularly in patients with an unsatisfactory response to rituximab.