RESUMO
The addition of darolutamide, an androgen receptor signalling inhibitor, to therapy with docetaxel has recently been approved as a strategy to treat metastatic prostate cancer. OATP1B3 is an SLC transporter that is highly expressed in prostate cancer and is responsible for the accumulation of substrates, including docetaxel, into tumours. Given that darolutamide inhibits OATP1B3 in vitro, we sought to characterise the impact of darolutamide on docetaxel pharmacokinetics. We investigated the influence of darolutamide on OATP1B3 transport using in vitro and in vivo models. We assessed the impact of darolutamide on the tumour accumulation of docetaxel in a patient-derived xenograft (PDX) model and on an OATP1B biomarker in patients. Darolutamide inhibited OATP1B3 in vitro at concentrations higher than the reported Cmax. Consistent with these findings, in vivo studies revealed that darolutamide does not influence the pharmacokinetics of Oatp1b substrates, including docetaxel. Docetaxel accumulation in PDX tumours was not decreased in the presence of darolutamide. Metastatic prostate cancer patients had similar levels of OATP1B biomarkers, regardless of treatment with darolutamide. Consistent with a low potential to inhibit OATP1B3-mediated transport in vitro, darolutamide does not significantly impede the transport of Oatp1b substrates in vivo or in patients. Our findings support combined treatment with docetaxel and darolutamide, as no OATP1B3 transporter based drug-drug interaction was identified.
Assuntos
Docetaxel , Neoplasias da Próstata , Pirazóis , Membro 1B3 da Família de Transportadores de Ânion Orgânico Carreador de Soluto , Ensaios Antitumorais Modelo de Xenoenxerto , Humanos , Masculino , Docetaxel/farmacologia , Docetaxel/farmacocinética , Animais , Camundongos , Membro 1B3 da Família de Transportadores de Ânion Orgânico Carreador de Soluto/metabolismo , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Pirazóis/farmacologia , Pirazóis/farmacocinética , Interações Medicamentosas , Linhagem Celular Tumoral , Células HEK293RESUMO
Previous studies have suggested that the incidence of vincristine-induced peripheral neuropathy (VIPN) is potentially linked with cytochrome P450 (CYP)3A5, a polymorphic enzyme that metabolizes vincristine in vitro, and with concurrent use of azole antifungals such as ketoconazole. The assumed mechanism for these interactions is through modulation of CYP3A-mediated metabolism, leading to decreased vincristine clearance and increased susceptibility to VIPN. Given the controversy surrounding the contribution of these mechanisms, we directly tested these hypotheses in genetically engineered mouse models with a deficiency of the entire murine Cyp3a locus [Cyp3a(-/-) mice] and in humanized transgenic animals with hepatic expression of functional and nonfunctional human CYP3A5 variants. Compared with wild-type mice, the systemic exposure to vincristine was increased by only 1.15-fold (95% confidence interval, 0.84-1.58) in Cyp3a(-/-) mice, suggesting that the clearance of vincristine in mice is largely independent of hepatic Cyp3a function. In line with these observations, we found that Cyp3a deficiency or pretreatment with the CYP3A inhibitors ketoconazole or nilotinib did not influence the severity and time course of VIPN and that exposure to vincristine was not substantially altered in humanized CYP3A5*3 mice or humanized CYP3A5*1 mice compared with Cyp3a(-/-) mice. Our study suggests that the contribution of CYP3A5-mediated metabolism to vincristine elimination and the associated drug-drug interaction potential is limited and that plasma levels of vincristine are unlikely to be strongly predictive of VIPN. SIGNIFICANCE STATEMENT: The current study suggests that CYP3A5 genotype status does not substantially influence vincristine disposition and neurotoxicity in translationally relevant murine models. These findings raise concerns about the causality of previously reported relationships between variant CYP3A5 genotypes or concomitant azole use with the incidence of vincristine neurotoxicity.
Assuntos
Citocromo P-450 CYP3A , Cetoconazol , Humanos , Animais , Camundongos , Vincristina/toxicidade , Vincristina/metabolismo , Vincristina/uso terapêutico , Citocromo P-450 CYP3A/genética , Cetoconazol/farmacologia , Inibidores do Citocromo P-450 CYP3A/farmacologia , Genótipo , AzóisRESUMO
Doxorubicin is a commonly used anticancer agent that can cause debilitating and irreversible cardiac injury. The initiating mechanisms contributing to this side effect remain unknown, and current preventative strategies offer only modest protection. Using stem-cell-derived cardiomyocytes from patients receiving doxorubicin, we probed the transcriptomic landscape of solute carriers and identified organic cation transporter 3 (OCT3) (SLC22A3) as a critical transporter regulating the cardiac accumulation of doxorubicin. Functional validation studies in heterologous overexpression models confirmed that doxorubicin is transported into cardiomyocytes by OCT3 and that deficiency of OCT3 protected mice from acute and chronic doxorubicin-related changes in cardiovascular function and genetic pathways associated with cardiac damage. To provide proof-of-principle and demonstrate translational relevance of this transport mechanism, we identified several pharmacological inhibitors of OCT3, including nilotinib, and found that pharmacological targeting of OCT3 can also preserve cardiovascular function following treatment with doxorubicin without affecting its plasma levels or antitumor effects in multiple models of leukemia and breast cancer. Finally, we identified a previously unrecognized, OCT3-dependent pathway of doxorubicin-induced cardiotoxicity that results in a downstream signaling cascade involving the calcium-binding proteins S100A8 and S100A9. These collective findings not only shed light on the etiology of doxorubicin-induced cardiotoxicity, but also are of potential translational relevance and provide a rationale for the implementation of a targeted intervention strategy to prevent this debilitating side effect.
Assuntos
Doxorrubicina/efeitos adversos , Traumatismos Cardíacos/induzido quimicamente , Traumatismos Cardíacos/tratamento farmacológico , Terapia de Alvo Molecular , Transportadores de Ânions Orgânicos Sódio-Independentes/metabolismo , Animais , Criança , Regulação da Expressão Gênica , Traumatismos Cardíacos/fisiopatologia , Humanos , Camundongos , Miócitos Cardíacos/metabolismo , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Transportadores de Ânions Orgânicos Sódio-Independentes/deficiência , Pirimidinas/farmacologia , Pirimidinas/uso terapêutico , Análise de Sequência de RNARESUMO
Dofetilide is a rapid delayed rectifier potassium current inhibitor widely used to prevent the recurrence of atrial fibrillation and flutter. The clinical use of this drug is associated with increases in QTc interval, which predispose patients to ventricular cardiac arrhythmias. The mechanisms involved in the disposition of dofetilide, including its movement in and out of cardiomyocytes, remain unknown. Using a xenobiotic transporter screen, we identified MATE1 (SLC47A1) as a transporter of dofetilide and found that genetic knockout or pharmacological inhibition of MATE1 in mice was associated with enhanced retention of dofetilide in cardiomyocytes and increased QTc prolongation. The urinary excretion of dofetilide was also dependent on the MATE1 genotype, and we found that this transport mechanism provides a mechanistic basis for previously recorded drug-drug interactions of dofetilide with various contraindicated drugs, including bictegravir, cimetidine, ketoconazole, and verapamil. The translational significance of these observations was examined with a physiologically-based pharmacokinetic model that adequately predicted the drug-drug interaction liabilities in humans. These findings support the thesis that MATE1 serves a conserved cardioprotective role by restricting excessive cellular accumulation and warrant caution against the concurrent administration of potent MATE1 inhibitors and cardiotoxic substrates with a narrow therapeutic window.
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Antiarrítmicos , Fibrilação Atrial , Animais , Antiarrítmicos/farmacologia , Humanos , Camundongos , Fenetilaminas/farmacologia , Sulfonamidas/uso terapêuticoRESUMO
Gilteritinib, an FDA-approved tyrosine kinase inhibitor approved for the treatment of relapsed/refractory FLT3-mutated acute myeloid leukemia, is primarily eliminated via CYP3A4-mediated metabolism, a pathway that is sensitive to the co-administration of known CYP3A4 inhibitors, such as itraconazole. However, the precise mechanism by which itraconazole and other CYP3A-modulating drugs affect the absorption and disposition of gilteritinib remains unclear. In the present investigation, we demonstrate that pretreatment with itraconazole is associated with a significant increase in the systemic exposure to gilteritinib in mice, recapitulating the observed clinical drug-drug interaction. However, the plasma levels of gilteritinib were only modestly increased in CYP3A-deficient mice and not further influenced by itraconazole. Ensuing in vitro and in vivo studies revealed that gilteritinib is a transported substrate of OATP1B-type transporters, that gilteritinib exposure is increased in mice with OATP1B2 deficiency, and that the ability of itraconazole to inhibit OATP1B-type transport in vivo is contingent on its metabolism by CYP3A isoforms. These findings provide new insight into the pharmacokinetic properties of gilteritinib and into the molecular mechanisms underlying drug-drug interactions with itraconazole.
Assuntos
Itraconazol , Leucemia Mieloide Aguda , Camundongos , Animais , Itraconazol/farmacologia , Citocromo P-450 CYP3A/genética , Inibidores do Citocromo P-450 CYP3A/farmacologia , Compostos de Anilina/farmacologia , Leucemia Mieloide Aguda/tratamento farmacológico , Inibidores de Proteínas Quinases/farmacologiaRESUMO
Sleep deprivation is associated with increased risk of myocardial infarction. However, it is unknown whether the effects of sleep deprivation are limited to increasing the likelihood of experiencing a myocardial infarction or if sleep deprivation also increases the extent of myocardial injury. In this study, rats were deprived of paradoxical sleep for 96 h using the platform-over-water method. Control rats were subjected to the same condition except the control platform was large enough for the rats to sleep. Hearts from sleep deprived and control rats were subjected to 20 min ischemia on a Langendorff isolated heart system. Infarct size and post ischemic recovery of contractile function were unaffected by sleep deprivation in male hearts. In contrast, hearts from sleep-deprived females exhibited significantly larger infarcts than hearts from control females. Post ischemic recovery of rate pressure product and + dP/dT were significantly attenuated by sleep deprivation in female hearts, and post ischemic recovery of end diastolic pressure was significantly elevated in hearts from sleep deprived females compared to control females, indicating that post ischemic recovery of both systolic and diastolic function were worsened by sleep deprivation. These data provide evidence that sleep deprivation increases the extent of ischemia-induced injury in a sex-dependent manner.
Assuntos
Coração/fisiopatologia , Infarto do Miocárdio/patologia , Miocárdio/patologia , Recuperação de Função Fisiológica/fisiologia , Privação do Sono/fisiopatologia , Animais , Pressão Sanguínea/fisiologia , Diástole , Feminino , Masculino , Infarto do Miocárdio/fisiopatologia , Ratos , Ratos Sprague-Dawley , Fatores SexuaisRESUMO
Individuals with post-traumatic stress disorder (PTSD) experience many debilitating symptoms, including intrusive memories, persistent anxiety and avoidance of trauma-related cues. PTSD also results in numerous physiological complications, including increased risk for cardiovascular disease (CVD). However, characterization of PTSD-induced cardiovascular alterations is lacking, especially in preclinical models of the disorder. Thus, we examined the impact of a psychosocial predator-based animal model of PTSD on myocardial sensitivity to ischemic injury. Male and female Sprague-Dawley rats were exposed to psychosocial stress or control conditions for 31 days. Stressed rats were given two cat exposures, separated by a period of 10 days, and were subjected to daily social instability throughout the paradigm. Control rats were handled daily for the duration of the experiment. Rats were tested on the elevated plus maze (EPM) on day 32, and hearts were isolated on day 33 and subjected to 20 min ischemia and 2 h reperfusion on a Langendorff isolated heart system. Stressed male and female rats gained less body weight relative to controls, but only stressed males exhibited increased anxiety on the EPM. Male, but not female, rats exposed to psychosocial stress exhibited significantly larger infarcts and attenuated post-ischemic recovery of contractile function compared to controls. Our data demonstrate that predator stress combined with daily social instability sex-dependently increases myocardial sensitivity to ischemic injury. Thus, this manipulation may be useful for studying potential mechanisms underlying cardiovascular alterations in PTSD, as well as sex differences in the cardiovascular stress response.
Assuntos
Coração/fisiopatologia , Isquemia Miocárdica/fisiopatologia , Transtornos de Estresse Pós-Traumáticos/fisiopatologia , Estresse Psicológico/fisiopatologia , Animais , Ansiedade/fisiopatologia , Sinais (Psicologia) , Modelos Animais de Doenças , Feminino , Masculino , Ratos , Ratos Sprague-Dawley , Caracteres Sexuais , Transtornos de Estresse Pós-Traumáticos/etiologia , Estresse Psicológico/complicaçõesRESUMO
Decitabine is a DNA methyltransferase inhibitor used in the treatment of acute myeloid leukemia and myelodysplastic syndrome. The notion that ongoing trials are presently exploring the combined use of decitabine, with or without the cytidine deaminase inhibitor cedazuridine, and other antileukemic drugs necessitates a comprehensive understanding of pharmacokinetic properties and an evaluation of drug-drug interaction liabilities. We report here the development and validation of a sensitive UHPLC-MS/MS method for quantifying decitabine in mouse plasma, which should be useful for such studies. The method involved a one-step protein precipitation extraction, and chromatographic separation on an XBridge HILIC column using gradient elution. The method was found to be robust, accurate, precise, and sufficiently sensitive (lower limit of quantitation, 0.4 ng/mL) to determine decitabine concentrations in microvolumes of plasma from mice receiving the agent orally or intravenously in the presence or absence of cedazuridine.
Assuntos
Decitabina , Espectrometria de Massas em Tandem , Animais , Espectrometria de Massas em Tandem/métodos , Decitabina/farmacocinética , Decitabina/sangue , Decitabina/administração & dosagem , Camundongos , Cromatografia Líquida de Alta Pressão/métodos , Reprodutibilidade dos Testes , Azacitidina/farmacocinética , Azacitidina/sangue , Azacitidina/análogos & derivados , Azacitidina/administração & dosagem , Azacitidina/química , Modelos Lineares , Uridina/farmacocinética , Uridina/sangue , Uridina/análogos & derivados , Sensibilidade e Especificidade , Limite de DetecçãoRESUMO
A recent article characterized dosing recommendations for cabozantinib in people living with HIV (PLWH) and cancer, a group that is often excluded from clinical trials. This study suggests cabozantinib is effective in cancers disproportionately impacting PLWH and has translational implications for the design of studies evaluating drug-drug interactions. See related article by Haigentz et al., p. 5038.
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Infecções por HIV , Neoplasias , Humanos , Infecções por HIV/complicações , Infecções por HIV/tratamento farmacológico , Neoplasias/complicações , Neoplasias/tratamento farmacológico , Anilidas/efeitos adversos , Piridinas/efeitos adversosRESUMO
A rapid, sensitive, and simple UHPLC-MS/MS method for the determination of the PARP inhibitor talazoparib in mouse plasma was developed and validated using [13C,2H4]-talazoparib as an internal standard (IS). The assay procedure involved extraction of talazoparib and the IS from plasma using a single-step deproteination and separation of the analytes was achieved on an ACQUITY UPLC RP18 HSS T3 column with a mobile phase gradient at a flow rate of 0.4 mL/min in a run time of 5 min. The calibration curve was linear (r2 > 0.99) over the concentration range of 0.5-100 ng/mL, and 10-fold dilution of samples could be accurately quantitated. The matrix effect and mean extraction recovery for talazoparib were between 93.7-109% and 87.7-105%, respectively. Precision and percent bias of quality control samples were always less than ±15%, indicating reproducibility and accuracy of the method. Talazoparib demonstrated bench-top stability at room temperature for 6 h, auto-sampler and reinjection stability at 4 °C for at least 24 h, and no significant degradation was observed after three freeze-thaw cycles. The developed method was successfully applied to pharmacokinetic studies involving serial blood sampling after oral administration of talazoparib to wild-type mice and animals with a genetic deficiency of the efflux transporters ABCB1 (P-gp) and ABCG2 (BCRP). Together, our results demonstrate the successful development of a suitable analytical method for talazoparib in mouse plasma and suggest that mice are a useful model to evaluate transporter-mediated drug-drug interactions involving therapy with talazoparib.
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Oral anticancer drugs suffer from significant variability in pharmacokinetics and pharmacodynamics partially due to limited bioavailability. The limited bioavailability of anticancer drugs is due to both pharmaceutical limitations and physiological barriers. Pharmacokinetic boosting is a strategy to enhance the oral bioavailability of a therapeutic drug by inhibiting physiological barriers through an intentional drug-drug interaction (DDI). This type of strategy has proven effective across several therapeutic indications including anticancer treatment. Pharmacokinetic boosting could improve anticancer drugs lacking or with otherwise unacceptable oral formulations through logistic, economic, pharmacodynamic and pharmacokinetic benefits. Despite these benefits, pharmacokinetic boosting strategies could result in unintended DDIs and are only likely to benefit a limited number of targets. Highlighting this concern, pharmacokinetic boosting has mixed results depending on the boosted drug. While pharmacokinetic boosting did not significantly improve certain drugs, it has resulted in the commercial approval of boosted oral formulations for other drugs. Pharmacokinetic boosting to improve oral anticancer therapy is an expanding area of research that is likely to improve treatment options for cancer patients.
Assuntos
Antineoplásicos/farmacocinética , Interações Medicamentosas , Neoplasias/tratamento farmacológico , Administração Oral , Antineoplásicos/administração & dosagem , Disponibilidade Biológica , HumanosRESUMO
Glycochenodeoxycholate-3-sulfate (GCDCA-S) and chenodeoxycholate-24-glucuronide (CDCA-24G) are bile acid metabolites that potentially serve as endogenous biomarkers for drug-drug interactions mediated by the hepatic uptake transporters OATP1B1 and OATP1B3. We developed and validated a novel UHPLC-MS/MS method for the quantitative determination of GCDCA-S and CDCA-24G in mouse and human plasma with a lower limit of quantitation of 0.5 ng/mL. Chromatographic separation was achieved on an Accucore aQ column (50 mm × 2.1 mm, dp = 2.6 µm) maintained at 20 °C and a gradient mobile phase comprising 2 mM ammonium acetate in water and methanol. The extraction recoveries of GCDCA-S and CDCA-24G were >80 %, and linear (r2 > 0.99) calibration curves ranged 0.5-100 ng/mL (CDCA-24G and GCDCA-S in mouse plasma) or 0.5-1000 ng/mL (GCDCA-S in mouse plasma). Values for precision (CV < 11.6 %) and accuracy bias (10.9 %) of analyte-spiked quality control samples verified that water was an acceptable matrix to prepare calibrators. This method was successfully applied to establish baseline activity of OATP1B1/OATP1B3 in humans and mice and establish the in vivo effects of OATP1B1/OATP1B3 inhibitors rifampin and micafungin.
Assuntos
Glucuronídeos , Espectrometria de Massas em Tandem , Animais , Ácidos e Sais Biliares , Biomarcadores/metabolismo , Ácido Quenodesoxicólico , Cromatografia Líquida de Alta Pressão/métodos , Ácido Glicoquenodesoxicólico/análogos & derivados , Humanos , Metanol , Micafungina , Camundongos , Reprodutibilidade dos Testes , Rifampina/farmacologia , Espectrometria de Massas em Tandem/métodos , ÁguaRESUMO
Acute myeloid leukemia (AML) with mutations in the tumor suppressor gene TP53 confers a dismal prognosis with 3-year overall survival of <5%. While inhibition of kinases involved in cell cycle regulation induces synthetic lethality in a variety of TP53 mutant cancers, this strategy has not been evaluated in mutant TP53 AML. Previously, we demonstrated that TP-0903 is a novel multikinase inhibitor with low nM activity against AURKA/B, Chk1/2, and other cell cycle regulators. Here, we evaluated the preclinical activity of TP-0903 in TP53 mutant AML cell lines, including a single-cell clone of MV4-11 containing a TP53 mutation (R248W), Kasumi-1 (R248Q), and HL-60 (TP 53 null). TP-0903 inhibited cell viability (IC50, 12−32 nM) and induced apoptosis at 50 nM. By immunoblot, 50 nM TP-0903 upregulated pChk1/2 and pH2AX, suggesting induction of DNA damage. The combination of TP-0903 and decitabine was additive in vitro, and in vivo significantly prolonged median survival compared to single-agent treatments in mice xenografted with HL-60 (vehicle, 46 days; decitabine, 55 days; TP-0903, 63 days; combination, 75 days) or MV4-11 (R248W) (51 days; 62 days; 81 days; 89 days) (p < 0.001). Together, these results provide scientific premise for the clinical evaluation of TP-0903 in combination with decitabine in TP53 mutant AML.
RESUMO
In recent years, various endogenous compounds have been proposed as putative biomarkers for the hepatic uptake transporters OATP1B1 and OATP1B3 that have the potential to predict transporter-mediated drug-drug interactions (DDIs). However, these compounds have often been identified from top-down strategies and have not been fully utilized as a substitute for traditional DDI studies. In an attempt to eliminate observer bias in biomarker selection, we applied a bottom-up, untargeted metabolomics screening approach in mice and found that plasma levels of the conjugated bile acid chenodeoxycholate-24-glucuronide (CDCA-24G) are particularly sensitive to deletion of the orthologous murine transporter Oatp1b2 (31-fold increase vs. wild type) or the entire Oatp1a/1b(-/-)cluster (83-fold increased), whereas the humanized transgenic overexpression of hepatic OATP1B1 or OATP1B3 resulted in the partial restoration of transport function. Validation studies with the OATP1B1/OATP1B3 inhibitors rifampin and paclitaxel in vitro as well as in mice and human subjects confirmed that CDCA-24G is a sensitive and rapid response biomarker to dose-dependent transporter inhibition. Collectively, our study confirmed the ability of CDCA-24G to serve as a sensitive and selective endogenous biomarker of OATP1B-type transport function and suggests a template for the future development of biomarkers for other clinically important xenobiotic transporters.
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Despite the clinical benefit associated with gilteritinib in relapsed/refractory acute myeloid leukemia (AML), most patients eventually develop resistance through unknown mechanisms. To delineate the mechanistic basis of resistance to gilteritinib, we performed targeted sequencing and scRNASeq on primary FLT3-ITD-mutated AML samples. Co-occurring mutations in RAS pathway genes were the most common genetic abnormalities, and unresponsiveness to gilteritinib was associated with increased expression of bone marrow-derived hematopoietic cytokines and chemokines. In particular, we found elevated expression of the TEK-family kinase, BMX, in gilteritinib-unresponsive patients pre- and post-treatment. BMX contributed to gilteritinib resistance in FLT3-mutant cell lines in a hypoxia-dependent manner by promoting pSTAT5 signaling, and these phenotypes could be reversed with pharmacological inhibition and genetic knockout. We also observed that inhibition of BMX in primary FLT3-mutated AML samples decreased chemokine secretion and enhanced the activity of gilteritinib. Collectively, these findings indicate a crucial role for microenvironment-mediated factors modulated by BMX in the escape from targeted therapy and have implications for the development of novel therapeutic interventions to restore sensitivity to gilteritinib.
Assuntos
Compostos de Anilina , Leucemia Mieloide Aguda , Compostos de Anilina/farmacologia , Compostos de Anilina/uso terapêutico , Humanos , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/metabolismo , Mutação , Proteínas Tirosina Quinases/genética , Pirazinas/farmacologia , Pirazinas/uso terapêutico , Microambiente Tumoral , Tirosina Quinase 3 Semelhante a fms/genética , Tirosina Quinase 3 Semelhante a fms/uso terapêuticoRESUMO
Venetoclax, a BCL-2 inhibitor used to treat certain hematological cancers, exhibits low oral bioavailability and high interpatient pharmacokinetic variability. Venetoclax is commonly administered with prophylactic antifungal drugs that may result in drug interactions, of which the underlying mechanisms remain poorly understood. We hypothesized that antifungal drugs may increase venetoclax exposure through inhibition of both CYP3A-mediated metabolism and OATP1B-mediated transport. Pharmacokinetic studies were performed in wild-type mice and mice genetically engineered to lack all CYP3A isoforms, or OATP1B2 that received venetoclax alone or in combination with ketoconazole or micafungin. In mice lacking all CYP3A isoforms, venetoclax AUC was increased by 1.8-fold, and pretreatment with the antifungal ketoconazole further increased venetoclax exposure by 1.6-fold, despite the absence of CYP3A. Ensuing experiments demonstrated that the deficiency of OATP1B-type transporters is also associated with increases in venetoclax exposure, and that many antifungal drugs, including micafungin, posaconazole, and isavuconazole, are inhibitors of this transport mechanism both in vitro and in vivo. These studies have identified OATP1B-mediated transport as a previously unrecognized contributor to the elimination of venetoclax that is sensitive to inhibition by various clinically-relevant antifungal drugs. Additional consideration is warranted when venetoclax is administered together with agents that inhibit both CYP3A-mediated metabolism and OATP1B-mediated transport.
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Ibrutinib (Imbruvica; PCI-32765) is an orally administered inhibitor of Bruton's tyrosine kinase that has transformed the treatment of B-cell malignancies. However, ibrutinib has very low oral bioavailability that contributes to significant variability in systemic exposure between patients, and this has the potential to affect both efficacy and toxicity. We hypothesized that the oral bioavailability of ibrutinib is limited by CYP3A isoform-mediated metabolism, and that this pathway can be inhibited to improve the pharmacokinetic properties of ibrutinib. Pharmacokinetic studies were performed in wild-type mice and mice genetically engineered to lack all CYP3A isoforms [CYP3A(-/-)] that received ibrutinib alone or in combination with CYP3A inhibitors cobicistat or ketoconazole. Computational modeling was performed to derive doses of ibrutinib that, when given after a CYP3A inhibitor, results in therapeutically-relevant drug levels. Deficiency of CYP3A in mice was associated with a ~10-fold increase in the area under the curve of ibrutinib. This result could be phenocopied by administration of cobicistat before ibrutinib in wild-type mice, but cobicistat did not influence levels of ibrutinib in CYP3A(-/-) mice. Population pharmacokinetic and prospectively validated physiologically-based pharmacokinetic models established preclinical and clinical doses of ibrutinib that could be given safely in combination with cobicistat without negatively affecting anti-leukemic properties. These findings signify a dominant role for CYP3A-mediated metabolism in the elimination of ibrutinib, and suggest a role for pharmacological inhibitors of this pathway to intentionally modulate the plasma levels and improve the therapeutic use of this clinically important agent.
Assuntos
Citocromo P-450 CYP3A , Intervenção Coronária Percutânea , Animais , Camundongos , Citocromo P-450 CYP3A/genética , Piperidinas , Inibidores do Citocromo P-450 CYP3A/farmacologia , CobicistatRESUMO
Organic cation transporter 1 (OCT1) is a transporter that regulates the hepatic uptake and subsequent elimination of diverse cationic compounds. Although OCT1 has been involved in drug-drug interactions and causes pharmacokinetic variability of many prescription drugs, details of the molecular mechanisms that regulate the activity of OCT1 remain incompletely understood. Based on an unbiased phospho-proteomics screen, we identified OCT1 as a tyrosine-phosphorylated transporter, and functional validation studies using genetic and pharmacological approaches revealed that OCT1 is highly sensitive to small molecules that target the protein kinase YES1, such as dasatinib. In addition, we found that dasatinib can inhibit hepatic OCT1 function in mice as evidenced from its ability to modulate levels of isobutyryl L-carnitine, a hepatic OCT1 biomarker identified from a targeted metabolomics analysis. These findings provide novel insight into the post-translational regulation of OCT1 and suggest that caution is warranted with polypharmacy regimes involving the combined use of OCT1 substrates and kinase inhibitors that target YES1.
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Failure to recognize important features of a drug's pharmacokinetic characteristics is a key cause of inappropriate dose and schedule selection, and can lead to reduced efficacy and increased rate of adverse drug reactions requiring medical intervention. As oral chemotherapeutic agents, tyrosine kinase inhibitors (TKIs) are particularly prone to cause drug-drug interactions as many drugs in this class are known or suspected to potently inhibit the hepatic uptake transporters OATP1B1 and OATP1B3. In this article, we provide a comprehensive overview of the published literature and publicly-available regulatory documents in this rapidly emerging field. Our findings indicate that, while many TKIs can potentially inhibit the function of OATP1B1 and/or OATP1B3 and cause clinically-relevant drug-drug interactions, there are many inconsistencies between regulatory documents and the published literature. Potential explanations for these discrepant observations are provided in order to assist prescribing clinicians in designing safe and effective polypharmacy regimens, and to provide researchers with insights into refining experimental strategies to further predict and define the translational significance of TKI-mediated drug-drug interactions.
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A rapid and sensitive analytical method was developed to quantify venetoclax, an oral BH3-mimetic that blocks the anti-apoptotic protein BCL-2, in mouse plasma using ultra-high-performance liquid chromatography with electrospray ionization tandem mass spectrometric detection. Plasma protein precipitation was performed on 5 µL samples, and separation of the analytes was accomplished on an Accucore aQ column using gradient elution at a flow rate of 0.4 mL/min. The calibration curve was linear (R2 ≥ 0.99) over the concentration range of 5-1,000 ng/mL, and the lower limit of quantitation was 5 ng/mL. The intra-day and inter-day precisions (RSD%) were < 10.5%, and accuracies ranged from 94.4 to 106%. The developed method was successfully applied to pharmacokinetic studies involving serial 30 µL blood sampling from male and female mice after oral administration of venetoclax (10 mg/kg) alone or 30 min after oral administration of ketoconazole (50 mg/kg) or vehicle (PEG400). The observed pharmacokinetic profiles suggest venetoclax undergoes sexually dimorphic disposition in mice. However, regardless of sex, pharmacokinetic studies demonstrated that venetoclax AUC(0-6h) was increased greater than 2-fold with prior administration of ketoconazole. Overall, our pharmacokinetic studies suggest that mice could be a translationally relevant model for the characterization of venetoclax pharmacokinetics. We have developed an analytical method suitable for such murine pharmacokinetic studies.