Determination of Venetoclax Concentration in Plasma Using High-Performance Liquid Chromatography

Quality by Design Based Chromatography Technique Development and Validation for the Medicine Venetoclax (for Chronic Leukemia), in the Context of Impurities Including Degradation Products

The present research study describes the Venetoclax (VEN)-related substances test method using RP-HPLC/DAD techniques. It was developed and validated according to ICH Q14 and Q2(R2) guidelines. The substances were separated using an X-Bridge Phenyl column (150 mm × 4.6 mm, 3.5 μm) and a gradient program. The mobile phase A, consist 0.02 mM Na2HPO4 (pH 8.0) buffer and acetonitrile in an 80:20 v/v ratio. Mobile phase B was prepared using a 75:25 v/v mixture of acetonitrile and a pH 8.0 buffer and well mixed. The flow rate remains constant at 1.0 mL/min, traversing an appropriate gradient program. The VEN and its impurities were detected at 280 nm, with an injection volume of 15 μL and a runtime of 130 min. Moreover, we identified proper degradation impurities and sensitivity of VEN due to forced-degradation study experiments. The linearity and range of the testing procedure were validated by computing r2 values over 0.999. All organic impurities were recovered at a rate of 97.6%-106.0% with a relative standard deviation of 0.11%-4.35%. A robustness test was conducted utilizing the AQbD methodology. The proposed method was stability-indicating in nature and can be used for commercial samples in the pharmaceutical industries.

Pharmacokinetic analysis of crushed venetoclax tablets combined with azacitizine for recurrent pediatric acute myeloid leukemia (AML)

BACKGROUND

The efficacy of a combination therapy consisting of venetoclax (VEN) and azacytidine (AZA) for newly diagnosed acute myeloid leukemia (AML) has been confirmed in elderly patients. However, the clinical data on VEN for pediatric AML are limited. A combination therapy consisting of crushed VEN tablets and AZA (VEN/AZA) was administered to two children with recurrent AML. The pharmacokinetics of VEN were then analysed.

CASE PRESENTATION

[Patient 1] A 1-year-old, male patient who experienced an AML relapse following an allogeneic hematopoietic stem cell transplantation received three courses of VEN/AZA. At the initial dosage of VEN (8 mg/kg), the minimum plasma concentration (Cmin) was only 0.44 µg/ml, which was far less than the optimal Cmin of 1.2 µg/ml. Subsequent dose-escalation to 10 mg/kg only achieved Cmin 0.42 µg/ml. [Patient 2] A 3-year-old, female patient in whom infantile acute lymphoblastic leukemia was originally diagnosed experienced a recurrence in the form of AML after lineage-switching. Three courses of VEN/AZA were administered with the same therapeutic drug monitoring as in Case 1. The Cmin of VEN was 0.15 µg/ml at 8 mg/kg. Afterwards, voriconazole 16 mg/kg/day was begun for a concomitant fungal infection together with VEN 2 mg/kg. This combination finally achieved Cmin 1.14 µg/ml probably through CYP3A4 inhibition by voriconazole. In terms of safety, only grade 4 hematological adverse events were observed in both patients. In terms of efficacy, patient 1 and patient 2 achieved stable disease status for two months and six months, respectively.

CONCLUSION

Pediatric patients may scarcely achieve effective plasma concentration of VEN when crushed tablets are used at the same dosage as in adults.

Plasma concentrations of venetoclax and Pharmacogenetics correlated with drug efficacy in treatment naive leukemia patients: a retrospective study

Venetoclax (VEN) was the only Bcl-2 inhibitor approved yet and showed large differences in clinical efficacy. The aim of the study was to explore the relationships between the plasma concentration and efficacy of VEN, and identify potential influencing factors. A retrospective cohort study was conducted and a total of 76 trough (C0h) and 91 6 h post-dose plasma concentration (C6h) blood concentrations of VEN were collected in 54 patients. C6h/D concentration of VEN was found to be significantly correlated with treatment efficacy (p = 0.006) in leukemia patients with good or intermediate prognosis stratification. A ROC curve was then established and the cut-off value was calculated as 0.2868 μg/ml (AUC = 0.7097, p = 0.1081). Besides, patients co-administered with triazoles or carrying CYP3A5 rs776746 AA/AG genotypes were prone to induce higher VEN plasma concentration regardless of whether VEN dosage was reduced or not. Through LASSO-logistic regression and nomogram analysis, chemotherapy regimens and neutrophil percentages were identified as the critical elements that may predict drug response. Above all, in addition to identify prognostic stratification, AML patients taken with VEN were suggested to test plasma concentration routinely so as to achieve desired efficacy, especially when co-administered with triazoles or carried with CYP3A5 rs776746 AA/AG.

Increased trough concentration of venetoclax when combined with itraconazole for acute myeloid leukemia

The administration of venetoclax (Ven) with azacitidine (Aza) was used as induction or salvage therapy for 34 patients with acute myeloid leukemia (AML) in our institute. An itraconazole oral solution (ITCZ-OS) was administered to 17 patients (50%) as antifungal prophylaxis. The trough concentration of Ven was significantly higher in patients treated with ITCZ than in those who were not (median values, 1.31 μg/mL vs. 0.64 μg/mL; p = 0.0072). Ven concentrations were > 3 μg/mL in some patients treated with ITCZ and the patient with the highest Ven concentration (5.58 μg/mL) expired after grade 4 neutropenia persisted for more than 50 days after the 1st cycle of Ven/Aza. It was also found that the group with concentrations equal to or above 1.29 μg/mL showed a significantly higher rate of achieving CR or CRi (p = 0.039). In conclusion, the measurement of Ven concentrations in AML cases is essential in daily clinical practice, particularly in those receiving antifungal prophylaxis.

Individualized medication of venetoclax based on therapeutic drug monitoring in Chinese acute myeloid leukemia patients using an HPLC method

OBJECTIVE

The aim of this study was to establish a simple and sensitive high-performance liquid chromatography method for therapeutic drug monitoring of venetoclax (VEN) and optimize regimens.

METHODS

The analysis required the extraction of a 50 μl plasma sample and the precipitation of proteins using acetonitrile extraction. The chromatographic method employed a mobile phase of acetonitrile: 0.5% KH 2 PO 4 (pH 3.5) (60/40, v/v) on a Diamond C 18 (4.6 mm × 250 mm, 5 μm) column at a flow rate of 1.0 ml/min. The quantitative method was validated based on standards described in 'Bioanalytical Method Validation: Guidance for Industry' published by the US Food and Drug Administration (FDA).

RESULTS

The calibration curve was linear ( R2  = 0.9998) over the range of 75-4800 ng/ml, with limits of quantification of 25 ng/ml. The coefficients of intraday and interday validation, specificity, recovery, and stability all met the criteria of FDA guidance. The method was successfully applied to analyze VEN concentrations in 30 cases of acute myeloid leukemia patients. The peak concentration ( Cmax ) was 1881.19 ± 756.61 ng/ml, while the trough concentration ( Cmin ) was 1212.69 ± 767.92 ng/ml in acute myeloid leukemia patients.

CONCLUSION

Our study establishes a simple, precise, and sensitive high-performance liquid chromatography method for monitoring VEN and confirms its applicability for therapeutic drug monitoring of VEN in hematological cancers.

Molecularly Imprinted Electrochemical Sensor for the Ultrasensitive and Selective Detection of Venetoclax

In this study, a new electropolymerized molecularly imprinted polymer (MIP) film was synthesized on a glassy carbon electrode (GCE) by a photopolymerization (PP) method using acrylamide (AA) as a functional monomer and venetoclax (VEN) as a template molecule. Optimization steps of the MIP film were performed using ferrocyanide/ferricyanide [Fe(CN)6]3-/4- as a redox probe. Removal and rebinding of the template molecule were investigated by differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS). The analytical performance of PP-AA@MIP-GCE was evaluated by comparing the DPV response of MIP with that of nonimprinted polymer (NIP). The limit of detection (LOD) and limit of quantification (LOQ) for DPV determination of VEN on PP-AA@MIP-GCE were 0.016 and 0.055 pM, respectively, and the linearity range was found to be between 0.1 and 1.0 pM. The applicability and legitimacy of the constructed sensor were confirmed through its utilization on synthetic human serum. The selectivity of the sensor was demonstrated using molecules with structures similar to that of VEN and/or drug substances such as ibrutinib and azacitidine, which could potentially be used in combination with VEN. The developed PP-AA@MIP-GCE sensor exhibited high sensitivity and selectivity for VEN and is the first reported method for DPV determination of VEN.

Venetoclax dose adjustment due to drug-drug interactions: a case report and literature review

The primary aim of the study is to discuss the potential interactions between venetoclax and common drugs used in department of hematology and the corresponding effects on the efficacy and safety of venetoclax treatment. Here, we report an acute myeloid leukemia patient treated with venetoclax and posaconazole, and the dose of venetoclax was adjusted due to drug interactions. Clinical pharmacists actively participated in treatment of this patient to provide pharmacy care to assist clinicians to identify the venetoclax-induced liver function impairment and give timely management. The case reported here is hoped to provide reference for clinical venetoclax treatment in patients with such disease. Clinical pharmacists should actively participate in clinical treatment, actively screen potential drug interactions, strengthen cooperation and communication with doctors, provide patients with high-quality pharmaceutical services, and establish clinical pharmacists' status in the multidisciplinary treatment of tumor.

Utility of therapeutic drug monitoring of venetoclax in acute myeloid leukemia

The favorable outcomes of venetoclax-based regimens in older adults with acute myeloid leukemia (AML) may result in its regimen becoming the standard treatment. However, the dosage of venetoclax is fixed, irrespective of body surface area (BSA) or weight. Therefore, individualized dosing using therapeutic drug monitoring (TDM) may help optimize treatment in a safe and effective manner. Twelve patients with AML who received venetoclax-based treatment were enrolled in this study. Blood samples were collected before venetoclax administration, and the minimum plasma concentration (Cmin) was evaluated. The concentration of venetoclax was evaluated using a simple, sensitive, and cost-effective assay using high-performance liquid chromatography, as described previously. The median age was 74 (70-85) years. Ten patients received venetoclax in combination with azacitidine and one patient received low-dose cytarabine (LDAC). The patients BSA ranged from 1.345 to 1.912 m2 (median 1.543). The dose of venetoclax was 400 mg with azacitidine, and 600 mg with LDAC. In four patients who were taking CYP3A4 inhibitors, venetoclax was reduced to 50 mg according to the prescribing information. The Cmin ranged from 0.39 to 2.49, and the patient taking itraconazole showed highest Cmin regardless of the reduction of venetoclax. Most patients showed higher Cmin compared to the data from previous clinical trials, and BSA and venetoclax concentrations showed a negative correlation. Many Asian AML patients > 75 years old are petite and receive CYP3A4 inhibitors. Therefore, the TDM of venetoclax may be useful.