Daratumumab monotherapy for relapsed AL amyloidosis: a single center retrospective analysis

Treatment of relapsed AL amyloidosis remains challenging as patients frequently suffer from severe organ dysfunctions. Daratumumab, a cornerstone drug in multiple myeloma and newly diagnosed AL amyloidosis, has also shown promise in relapsed AL amyloidosis. To assess the efficacy of daratumumab, we conducted a retrospective study of 40 patients who received daratumumab monotherapy in our prospective amyloidosis cohort. The median age of the cohort was 67 years, and 31 patients were classified as stage III/IV by the Mayo 2012 guidelines and 32 patients as stage IIIa/IIIb by the European staging system. The overall hematologic and cardiac response rates were 72.5% and 42.4%, respectively. With median follow-up duration of 26.9 months, the estimated median progression-free survival was 21.9 months. Deep hematologic ( p < 0.001) and cardiac response ( p = 0.001) were associated with prolonged progression free survival. The duration of hematologic/cardiac responses were 26.2 months and 27.8 months, respectively. The median overall survival was 30.9 months. Treatment was well tolerated, as with 3 patients experiencing grade 3–4 hematologic adverse events and 8 experiencing grade 3–4 non-hematologic adverse events. Our findings suggest that daratumumab monotherapy provides rapid and durable responses and is generally well tolerated in patients with relapsed AL amyloidosis.