Abstract: Ｏｂｊｅｃｔｉｖｅ：To observe the clinical efficacy and safety of daratumumab in the treatment of relapse／refractory systemic light chain amyloidosis(AL).
Ｍｅｔｈｏｄｏｌｏｇｙ：Patients suffered relapse／refractory AL and received the treatment of daratumumab from July 2020 to December 2020 were enrolled. The clinical data was collected to evaluate hematological and organ responses, and adverse reactions were analyzed.
Ｒｅｓｕｌｔｓ：A total of 19 patients median aged 56 (47, 77) were enrolled, and the median disease course was 36 (21, 79) months. Seven cases (368％) were male, the others were female. Kidney was involved in all patients, and 11 (579％) cases had a heart involvement. According to the Mayo staging system and the European collaborative study,13 patients(684％) were classified to stage Ⅰ, 2 patients(105％) were classified to stage Ⅱ, while the others were classified to stage Ⅲa. Patients received 2(1, 4) line therapy before the treatment of daratumumab. After receiving 4 (3, 12) doses(16 mg／kg per dose), in 12 patients with difference free light chain>50 mg／L at baseline, 4 cases (333％) achieved complete remission, 6 cases (50％) achieved very good partial remission, while in 7 patients with difference free light chain between 20 to 50 mg／L at baseline, 6 cases reduced to<10 mg／L. After follow up of 4 (1, 7) months, all patients were survived, 3 (158％) cases achieved renal response, and in the 11 patients with heart involvement achieved heart response. Most of the adverse reactions were related to infusion and was classified to grade 1. Pulmonary infection occurred in one patient, and was cured after suitable antiinfective treatment.
Ｃｏｎｃｌｕｓｉｏｎ：Daratumumab is effective and safe in the treatment of relapse／refractory AL with high hematological response rate, and the organ response was found after a shortterm followup, but the longterm efficacy still need further observation.

Key words: Daratumumab, systemic light chain amyloidosis, efficacy, safety