Does baseline proteinuria affect the efficacy of obinutuzumab in patients with primary membranous nephropathy and minimal change disease? a single-center retrospective study.

BACKGROUND: Primary membranous nephropathy (PMN) and minimal change disease (MCD) are common causes of nephrotic syndrome in adults and represent the two diseases in which anti-CD20 monoclonal antibodies are most widely used. Previous studies have demonstrated that the clinical efficacy of rituximab (RTX) is influenced by the baseline level of proteinuria. Obinutuzumab is a novel anti-CD20 monoclonal antibody with superior efficacy and safety to RTX. However, whether its therapeutic efficacy in PMN and MCD is similarly influenced by baseline proteinuria remains unclear. METHODS: We recruited 40 patients with PMN and 42 patients with MCD confirmed by renal biopsy. All patients received obinutuzumab. All patients with PMN were divided into two groups based on baseline proteinuria: ≤8 g/d group and >8 g/d group. MCD patients were divided into two groups: the GC + obinutuzumab group and the Obinutuzumab group. Compared the clinical outcomes and side-effects of patients in different groups after a 12-month follow-up. RESULTS: Among patients with PMN and MCD, no statistically significant differences were observed between the two groups in complete remission (CR) rates, partial remission (PR) rates, or composite remission rates at the first, third, sixth, ninth, and 12th months. Kaplan-Meier analysis showed that there is no significant difference in cumulative CR rates and composite remission rates between two groups in patients with PMN and patients with MCD. At the end of follow-up, all patients exhibited a significant reduction in proteinuria, an increase in serum albumin, and no deterioration in kidney function. Furthermore, the safety profile of obinutuzumab was favorable in this study. CONCLUSION: Our findings suggest that the efficacy of obinutuzumab in PMN and MCD is not affected by the baseline level of proteinuria. Besides, obinutuzumab monotherapy has shown satisfactory therapeutic effects in both PMN and MCD.