The clinical efficacy of a daratumumab-based regimen in relapsed/refractory acute leukemia: a single-center experience

Relapsed/refractory acute leukemia (R/R-AL) is associated with a low remission rate, short survival rate, and poor prognosis. Treating R/R-AL remains challenging as there is no standardized effective regimen; hence, there is a need for efficient therapies. CD38 expression has been observed in acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL). Daratumumab is a humanized anti-CD38 monoclonal antibody used to treat multiple myeloma and has been reported to treat R/R-AL safely and effectively. The clinical data of 10 adult patients with R/R-AL who were treated with a daratumumab-based salvage regimen between July 2018 and May 2023 at our center were analyzed retrospectively. Seven AML and three ALL cases were included in the analysis. Seven (70%) patients showed responses to the treatments (complete response [CR], 60%; partial response [PR], 10%). Of the seven responders, three underwent allogenic stem cell transplantation (ASCT), including one who underwent a second ASCT. Among the five patients with R/R AML who had prior exposure to venetoclax, three achieved a therapeutic response (two CR and one PR) when re-treated with venetoclax in combination with daratumumab. The median follow-up time was 6.15 months (0.9-21 months). Overall survival and event-free survival rates at 12 months were 68.6% and 40.0%, respectively. The main adverse events included grade 3 febrile neutropenia (20%) and grade 3 hematological toxicities (60%). The daratumumab-based salvage regimen offers patients with R/R-AL the opportunity of remission with acceptable tolerability, creating the possibility of bridging ASCT.