Abstract: Ｏｂｊｅｃｔｉｖｅ：To observe the clinical efficacy and safety of daratumumab in  treatment of relapse／refractory monoclonal gammopathy of renal significance(MGRS).
Ｍｅｔｈｏｄｏｌｏｇｙ：Patients suffered relapse／refractory MGRS and received the treatment of daratumumab from Septmeber 2021 to January 2023 were enrolled in the study. The clinical data was collected to evaluate hematological and renal responses, adverse reactions were analyzed.
Ｒｅｓｕｌｔｓ：Five patients were enrolled, with a median age of 51 (50, 57) years and a median disease duration of 58 (23, 59) months. Two patients were diagnosed light chain deposition disease (LCDD), two patients were diagnosed proliferative glomerulonephritis with monoclonal immunoglobulin deposition (PGNMID) and the other one was monoclonal immunoglobulin-related C3 glomerulopathy. After receiving of daratumumab, one of the two patients with difference free light chain>50 mg／L achieved hematological complete response and the other one achieved partial response, while two of the three patients with difference free light chain between 20~50 mg／L decreased to <10 mg／L. After a follow-up of 10 (9, 12) months, all five patients were alive, and two achieved renal response. Infusion-related adverse reactions included cough, chills and throat discomfort, and all were classified to grade 1. In addition, one patient had low degree fever unrelated to infection, and mild neutropenia occured in one patient.
Ｃｏｎｃｌｕｓｉｏｎ：Daratumumab is effective and safe in treatment of relapse／refractory MGRS, the hematological response rate was high, and renal response was observed in some patients.

Key words: daratumumab, monoclonal gammopathy of renal significanc, eefficacy, safety