There is significant reduction in number of approved drugs for acute myeloid leukemia in recent years. Partially it may be due to the failure of discovery and validation approach to new drugs as well as the complexity of the disease. Ex vivo functional drug testing is a promising approach to identify novel treatment strategies for acute myeloid leukemia (AML). In ideal condition, an effective drug should eradicate the immature AML blasts, but spare non-malignant hematopoietic cells. However, current strategies like conventional cell viability assay fail to measure cell population-specific drug responses. Hence, development of more advanced approaches is needed. Using multiparameter, high-content flow cytometry (FC), we simultaneously evaluated the ex vivo sensitivity of different cell populations in multiple (10) primary AML samples to 7 FDA/EMA-approved drugs and 8 drug combinations. Amongst the 7 tested drugs, venetoclax, cytarabine and dasatinib were very cytotoxic with venetoclax had the highest blast-specific toxicity, and combining cytarabine with JAK inhibitor ruxolitinib effectively targeted all leukemic blasts but spared non-malignant hematopoietic cells. Taken together, we show that the ex vivo efficacy of targeted agents for specific AML cell population can be assessed with a cell phenotype, FC-based approach. Furthermore, we put an effort to analyze the potential of this assay and biomarkers to predict the clinical outcome of individual patients and future perspectives.
