Development and validation of a liquid chromatography-tandem mass spectrometry assay for nine oral anticancer drugs in human plasma

A liquid chromatography-tandem mass spectrometry assay was developed and validated for the nine oral anticancer agents alectinib, cobimetinib, lenvatinib, nintedanib, osimertinib, palbociclib, ribociclib, vismodegib and vorinostat in order to support therapeutic drug monitoring (TDM). The assay was based on reversed-phase chromatography coupled with tandem mass spectrometry operating in the positive ion mode. The assay was validated based on the guidelines on bioanalytical methods by the US Food and Drug Administration and European Medicines Agency. The method was validated over a linear range of 10-200 ng/mL for alectinib, lenvatinib, nintedanib and vismodegib; 50-1000 ng/mL for cobimetinib and palbociclib; 100-2000 ng/mL for osimertinib; 5.00-100 ng/mL for ribociclib; 25-500 ng/mL for vorinostat. Intra-assay and inter-assay bias was within ±20% for all analytes at the lower limit of quantification and within ±15% at remaining concentrations. Stability experiments showed that osimertinib is unstable in the biomatrix and should be shipped on dry-ice and stored at -20 °C until analysis. All other compounds were stable in the biomatrix. The described TDM method was successfully validated and applied for TDM in patients treated with these KIs

Development and validation of a liquid chromatography-tandem mass spectrometry assay for nine oral anticancer drugs in human plasma

A liquid chromatography-tandem mass spectrometry assay was developed and validated for the nine oral anticancer agents alectinib, cobimetinib, lenvatinib, nintedanib, osimertinib, palbociclib, ribociclib, vismodegib and vorinostat in order to support therapeutic drug monitoring (TDM). The assay was based on reversed-phase chromatography coupled with tandem mass spectrometry operating in the positive ion mode. The assay was validated based on the guidelines on bioanalytical methods by the US Food and Drug Administration and European Medicines Agency. The method was validated over a linear range of 10-200 ng/mL for alectinib, lenvatinib, nintedanib and vismodegib; 50-1000 ng/mL for cobimetinib and palbociclib; 100-2000 ng/mL for osimertinib; 5.00-100 ng/mL for ribociclib; 25-500 ng/mL for vorinostat. Intra-assay and inter-assay bias was within ±20% for all analytes at the lower limit of quantification and within ±15% at remaining concentrations. Stability experiments showed that osimertinib is unstable in the biomatrix and should be shipped on dry-ice and stored at -20 °C until analysis. All other compounds were stable in the biomatrix. The described TDM method was successfully validated and applied for TDM in patients treated with these KIs

Development and validation of a liquid chromatography-tandem mass spectrometry assay for nine oral anticancer drugs in human plasma

A liquid chromatography-tandem mass spectrometry assay was developed and validated for the nine oral anticancer agents alectinib, cobimetinib, lenvatinib, nintedanib, osimertinib, palbociclib, ribociclib, vismodegib and vorinostat in order to support therapeutic drug monitoring (TDM). The assay was based on reversed-phase chromatography coupled with tandem mass spectrometry operating in the positive ion mode. The assay was validated based on the guidelines on bioanalytical methods by the US Food and Drug Administration and European Medicines Agency. The method was validated over a linear range of 10-200 ng/mL for alectinib, lenvatinib, nintedanib and vismodegib; 50-1000 ng/mL for cobimetinib and palbociclib; 100-2000 ng/mL for osimertinib; 5.00-100 ng/mL for ribociclib; 25-500 ng/mL for vorinostat. Intra-assay and inter-assay bias was within ±20% for all analytes at the lower limit of quantification and within ±15% at remaining concentrations. Stability experiments showed that osimertinib is unstable in the biomatrix and should be shipped on dry-ice and stored at -20 °C until analysis. All other compounds were stable in the biomatrix. The described TDM method was successfully validated and applied for TDM in patients treated with these KIs

LC-MS/MS assay for the quantification of testosterone, dihydrotestosterone, androstenedione, cortisol and prednisone in plasma from castrated prostate cancer patients treated with abiraterone acetate or enzalutamide

Prostate cancer is the most common malignancy among men in the Western world. Treatment of this patient population, e.g. by (chemical) castration, is primarily focused on depletion of tumor-stimulating androgens, with testosterone being the major androgenic hormone. After initial therapy, prostate cancer may progress to metastatic castration-resistant prostate cancer. Anti-hormonal drugs abiraterone acetate and enzalutamide are commonly used to treat patients with this disease as both drugs reduce tumor growth and increase time to tumor progression. To evaluate the pharmacodynamic effects of anti-hormonal drugs in this patient population, we developed an LC-MS/MS method for the quantification of testosterone, dihydrotestosterone, androstenedione, cortisol and prednisone in human plasma. The validated assay ranges from 10-10,000 pg/mL for testosterone and androstenedione, 100-10,000 pg/mL for dihydrotestosterone, 50-5000 pg/mL for cortisol and 500-50,000 pg/mL for prednisone. Intra-assay and inter-assay variabilities were within ±15% of the nominal concentrations for quality control (QC) samples at low, medium and high concentrations and within ±20% at the lower limit of quantification (LLOQ), respectively. The applicability of the method was demonstrated in plasma from patients with metastatic castrated-resistant prostate cancer using either abiraterone acetate or enzalutamide

LC-MS/MS assay for the quantification of testosterone, dihydrotestosterone, androstenedione, cortisol and prednisone in plasma from castrated prostate cancer patients treated with abiraterone acetate or enzalutamide

Prostate cancer is the most common malignancy among men in the Western world. Treatment of this patient population, e.g. by (chemical) castration, is primarily focused on depletion of tumor-stimulating androgens, with testosterone being the major androgenic hormone. After initial therapy, prostate cancer may progress to metastatic castration-resistant prostate cancer. Anti-hormonal drugs abiraterone acetate and enzalutamide are commonly used to treat patients with this disease as both drugs reduce tumor growth and increase time to tumor progression. To evaluate the pharmacodynamic effects of anti-hormonal drugs in this patient population, we developed an LC-MS/MS method for the quantification of testosterone, dihydrotestosterone, androstenedione, cortisol and prednisone in human plasma. The validated assay ranges from 10-10,000 pg/mL for testosterone and androstenedione, 100-10,000 pg/mL for dihydrotestosterone, 50-5000 pg/mL for cortisol and 500-50,000 pg/mL for prednisone. Intra-assay and inter-assay variabilities were within ±15% of the nominal concentrations for quality control (QC) samples at low, medium and high concentrations and within ±20% at the lower limit of quantification (LLOQ), respectively. The applicability of the method was demonstrated in plasma from patients with metastatic castrated-resistant prostate cancer using either abiraterone acetate or enzalutamide

Determination of the absolute bioavailability of oral imatinib using a stable isotopically labeled intravenous imatinib-d8 microdose

PURPOSE: The aim of this study was to ascertain whether the absolute bioavailability of oral imatinib (Glivec®) during steady state plasma pharmacokinetics in cancer patients could be determined through a concomitant intravenous administration of a single 100 μg microdose of deuterium labeled imatinib (imatinib-d8). Secondly, the usefulness of liquid chromatography-tandem mass spectrometry (LC-MS/MS) was investigated for simultaneous analysis of orally and intravenously administered imatinib. METHODS: Included patients were on a stable daily dose of 400 mg oral imatinib prior to study participation. On day 1, patients received a 100 μg intravenous imatinib-d8 microdose 2.5 h after intake of the oral dose. Plasma samples were collected for 48 h. Imatinib and imatinib-d8 concentrations were simultaneously quantified using a validated LC-MS/MS assay. The absolute bioavailability was calculated by comparing the dose-normalized exposure with unlabeled and stable isotopically labeled imatinib in plasma. RESULTS: A total of six patients were enrolled. All patients had a history of gastrointestinal stromal tumors (GIST). The median absolute bioavailability of oral imatinib at steady state was 76% (range 44-106%). Imatinib and imatinib-d8 plasma concentrations were quantified in all collected plasma samples, with no samples below the limit of quantification for imatinib-d8. CONCLUSION: The absolute bioavailability of imatinib was successfully estimated at steady state plasma pharmacokinetics using the stable isotopically labeled microdose trial design. This study exhibits the use of a stable isotopically labeled intravenous microdose to determine the absolute bioavailability of an oral anticancer agent in patients with LC-MS/MS as the analytical tool

Determination of the absolute bioavailability of oral imatinib using a stable isotopically labeled intravenous imatinib-d8 microdose

PURPOSE: The aim of this study was to ascertain whether the absolute bioavailability of oral imatinib (Glivec®) during steady state plasma pharmacokinetics in cancer patients could be determined through a concomitant intravenous administration of a single 100 μg microdose of deuterium labeled imatinib (imatinib-d8). Secondly, the usefulness of liquid chromatography-tandem mass spectrometry (LC-MS/MS) was investigated for simultaneous analysis of orally and intravenously administered imatinib. METHODS: Included patients were on a stable daily dose of 400 mg oral imatinib prior to study participation. On day 1, patients received a 100 μg intravenous imatinib-d8 microdose 2.5 h after intake of the oral dose. Plasma samples were collected for 48 h. Imatinib and imatinib-d8 concentrations were simultaneously quantified using a validated LC-MS/MS assay. The absolute bioavailability was calculated by comparing the dose-normalized exposure with unlabeled and stable isotopically labeled imatinib in plasma. RESULTS: A total of six patients were enrolled. All patients had a history of gastrointestinal stromal tumors (GIST). The median absolute bioavailability of oral imatinib at steady state was 76% (range 44-106%). Imatinib and imatinib-d8 plasma concentrations were quantified in all collected plasma samples, with no samples below the limit of quantification for imatinib-d8. CONCLUSION: The absolute bioavailability of imatinib was successfully estimated at steady state plasma pharmacokinetics using the stable isotopically labeled microdose trial design. This study exhibits the use of a stable isotopically labeled intravenous microdose to determine the absolute bioavailability of an oral anticancer agent in patients with LC-MS/MS as the analytical tool