High-throughput UHPLC-MS/MS Assay for the Quantification of Venetoclax in Patients with Acute Myeloid Leukemia and...

Venetoclax is a B-cell lymphoma 2 inhibitor with breakthrough therapy designations and is used in the treatment of acute myeloid leukemia, particularly in patients ineligible for conventional cytotoxic chemotherapy. However, these drugs exhibit extensive pharmacokinetic variability among patients. Therapeutic drug monitoring (TDM) is useful in determining venetoclax dosage regimens. This study aimed to develop a high-throughput method for the quantification of plasma venetoclax concentration using ultrahigh-performance liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS) and to apply this method to TDM.

After a simple solid-phase extraction step using a 96-well µElution plate, venetoclax was analyzed using UHPLC-MS/MS in positive electrospray ionization mode. This novel method fulfilled the requirements of the US Food and Drug Administration guidelines for bioanalytical assay validation, with a 4 ng/mL lower limit of quantification. The calibration curves were linear over a concentration range of 4-50,000 ng/mL.

The recovery rate was 96.2 ± 18.0% (mean ± SD). The imprecision was below 7.2% coefficient of variation, and the accuracy was within 10.4% for all quality control levels. The matrix effect varied from 80.6% to 97.9%. This assay was successfully applied to the TDM of trough concentrations in 3 patients treated with venetoclax for acute myeloid leukemia.

We successfully developed a novel high-throughput UHPLC-MS/MS method for quantifying venetoclax in human plasma. This method can be applied for TDM in patients receiving venetoclax in clinical settings.