Impact of Venetoclax Trough Levels on Safety and Efficacy in the Treatment of Acute Myeloid Leukemia

Venetoclax-azacitidine chemotherapy is a key treatment for older or medically unfit patients with acute myeloid leukemia (AML). As venetoclax is metabolized via cytochrome P450 3A, dose adjustments are required when combined with antifungal agents. However, data on venetoclax concentrations and their impact on safety and efficacy remain limited. This study analyzed the association between venetoclax trough levels and treatment outcomes in 152 AML patients (median age: 70 years). The median trough level was 1,518 ng/mL (range: 60–11,328 ng/mL), with significant interindividual variability, even after adjusting for antifungal use. High venetoclax trough levels were significantly associated with elevated creatinine and total bilirubin levels. Patients with trough levels below 1857.3 ng/mL had lower rates of hematologic toxicity during the first treatment course (92.9% vs. 100%, P = 0.041). In the second course, hematologic toxicity was lower in patients with concentrations below 1,299.3 ng/mL (68% vs. 90%, P = 0.009). No significant correlation was found between venetoclax levels and treatment response. These findings highlight the need for venetoclax dose optimization based on drug levels to improve safety in AML treatment.