Background: Daratumumab is a monoclonal antibody, which targets CD38; an antigen expressed on malignant plasma cells in AL amyloidosis thus providing a rationale for its use.

Method: Patients treated with daratumumab monotherapy (2016–2019) for relapsed/refractory systemic AL amyloidosis were identified from the database at the UK National Amyloidosis Centre.

Results: Of 50 evaluable patients, haematological responses at 3 months were: CR – 19 (38%), VGPR – 14 (28%), PR – 9 (18%) and no response – 8 (16%). Median time to response was 1 (1–6) month. Of assessable patients, cardiac, renal and hepatic responses were seen in 43.8%, 25.0% and 0% of patients whilst progression occurred in 25.0%, 12.5% and 37.5% respectively. Patients achieving a CR had longer median OS (not reached vs. 22.7 months [95% CI 17.0–28.4 months]) (p = .036). Furthermore, patients achieving a rapid response (at 1 month) had a longer median PFS (not reached vs. 9 months [95% CI 5.8–12.2 months]) (p = .013).

Conclusion: Daratumumab monotherapy is effective in multiply-relapsed systemic AL amyloidosis and should be considered, if available, in patients who have not received prior daratumumab therapy. Responses are achieved rapidly and overall response rate was 84%. CR predicts overall survival whilst speed of response is predictive of a longer PFS.

背景： Daratumumab是一种针对CD38的单克隆抗体。一种在AL淀粉样变性中在恶性浆细胞上表达的抗原，因此为其应用提供了理论依据。

方法：从英国国家淀粉样变性病中心的数据库中识别出接受daratumumab单药治疗（2016-2019）的复发/难治性全身性AL淀粉样变性患者。

结果：在50例可评估患者中，3个月的血液学反应为：CR – 19（38％），VGPR – 14（28％），PR – 9（18％）和无反应– 8（16％）。中位反应时间为1（1-6）个月。在可评估的患者中，分别有43.8％，25.0％和0％的患者发现了心脏，肾脏和肝脏的反应，而进展程度分别为25.0％，12.5％和37.5％。获得CR的患者中位OS更长（未达到22.7个月[95％CI 17.0-28.4个月]）（p  = .036）。此外，达到快速反应（在1个月时）的患者的中位PFS较长（未达到vs. 9个月[95％CI 5.8-12.2个月]）（p  = 0.013）。

结论： Daratumumab单一疗法可有效治疗多发性系统性AL淀粉样变性，如果尚未接受daratumumab治疗，应考虑使用该疗法（如果有）。响应迅速实现，总体响应率为84％。CR可以预测总体生存率，而反应速度可以预测更长的PFS。