Comparing salvage intensive chemotherapy and venetoclax combined with low-intensity regimens in patients with relapsed/refractory acute myeloid leukemia

The study aimed to compare salvage intensive chemotherapy (IC) and a venetoclax (Venclexta; VEN)-combined low-intensity regimen in patients with relapsed/refractory (r/r) acute myeloid leukemia (AML).  

This study concluded that the VEN-combined regimen provided similar responses and survival rates when compared to salvage IC in these patients. 

Many patients with AML experience r/r disease despite progress in treatments. These patients need salvage treatments. Stem cell transplantation (SCT) can be a good option for these patients after successful salvage treatments. SCT involves transplanting healthy cells from the same patient or from a healthy donor.

Salvage treatment commonly involves IC. However, intensive IC can be very aggressive, particularly for older or frail patients. There is evidence that a venetoclax (VEN)-combined regimen is effective in patients with r/r AML. VEN is a targeted therapy that attacks a specific protein on leukemia cells and leads to cancer cell death. However, how a VEN-combined low-intensity regimen compared to IC as a salvage treatment in patients with r/r AML is still unknown. 

This study involved 143 patients with r/r AML. 89 patients received IC (group 1) and 54 received a VEN-combined low-intensity regimen (group 2) as their first- or second-line salvage treatment. The VEN regimen contained either hypomethylating agents or low-dose cytarabine (Cytosar-U). The follow-up period was 22.5 months for group 1 and 11.3 months for group 2.

Overall response rates were 44% for group 1 versus 59.3% for group 2. This difference was not considered statistically significant. However, patients in group 2 had lower treatment-related mortality when compared to group 1.  

68.5% of patients in both groups received an allogeneic SCT (SCT from a donor) after salvage therapy. The percentage of patients in group 1 that responded to SCT was 62.3% compared to 86.5% in group 2. The average time to receive an SCT was shorter for group 2 (103 days) compared to group 2 (140 days). 

The average overall survival was 8.9 months for group 1 compared to 12.4 months for group 2. 

This study concluded that the VEN-combined low-intensity regimen provided similar response and survival rates when compared to salvage IC in patients with r/r AML. It also provided a bridge to SCT with better disease control in these patients.  

This study had a small number of participants. The VEN combination was started later during the study and the follow-up period was much shorter compared to the IC group. This may have influenced the results.