RESUMEN
Novel combinations of specific opioid agonists like loperamide and oxymorphindole targeting the µ- and δ-opioid receptors, respectively, have shown increased potency with minimized opioid-associated risks. However, whether their interaction is pharmacokinetic or pharmacodynamic in nature has not been determined. This study quantitatively determined whether these drugs have a pharmacokinetic interaction that alters systemic disposition or central nervous system (CNS) distribution. We performed intravenous and oral in vivo pharmacokinetic assessments of both drugs after discrete dosing and administration in combination to determine whether the combination had any effect on systemic pharmacokinetic parameters or CNS exposure. Drugs were administered at 5 or 10 mg/kg i.v. or 30 mg/kg orally to institute for cancer research (ICR) mice and 5 mg/kg i.v. to Friend leukemia virus strain B mice of the following genotypes: wild-type, breast cancer resistance protein (Bcrp-/- ) (Bcrp knockout), Mdr1a/b-/- [P-glycoprotein (P-gp) knockout], and Bcrp-/- Mdr1a/b-/- (triple knockout). In the combination, clearance of oxymorphindole (OMI) was reduced by approximately half, and the plasma area under the concentration-time curve (AUC) increased. Consequently, brain and spinal cord AUCs for OMI in the combination also increased proportionately. Both loperamide and OMI are P-gp substrates, but administration of the two drugs in combination does not alter efflux transport at the CNS barriers. Because OMI alone shows appreciable brain penetration but little therapeutic efficacy on its own, and because loperamide's CNS distribution is unchanged in the combination, the mechanism of action for the increased potency of the combination is most likely pharmacodynamic and most likely occurs at receptors in the peripheral nervous system. This combination has favorable characteristics for future development. SIGNIFICANCE STATEMENT: Opioids have yet to be replaced as the most effective treatments for moderate-to-severe pain and chronic pain, but their side effects are dangerous. Combinations of opioids with peripheral activity, such as loperamide and oxymorphindole, would be valuable in that they are effective at much lower doses and have reduced risks for dangerous side effects because the µ-opioid receptor agonist is largely excluded from the CNS.
Asunto(s)
Sistema Nervioso Central/metabolismo , Loperamida/farmacocinética , Morfolinas/farmacocinética , Receptores Opioides/agonistas , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/genética , Transportador de Casetes de Unión a ATP, Subfamilia G, Miembro 2/genética , Animales , Combinación de Medicamentos , Sinergismo Farmacológico , Femenino , Genotipo , Loperamida/administración & dosificación , Masculino , Ratones , Ratones Endogámicos ICR , Morfolinas/administración & dosificación , Distribución TisularRESUMEN
Bioluminescent imaging (BLI) is a powerful tool in biomedical research to measure gene expression and tumor growth. The current study examined factors that influence the BLI signal, specifically focusing on the tissue distribution of two luciferase substrates, D-luciferin and CycLuc1. D-luciferin, a natural substrate of firefly luciferase, has been reported to have limited brain distribution, possibly due to the efflux transporter, breast cancer resistance protein (Bcrp), at the blood-brain barrier. CycLuc1, a synthetic analog of D-luciferin, has a greater BLI signal at lower doses than D-luciferin, especially in the brain. Our results indicate that limited brain distribution of D-luciferin and CycLuc1 is predominantly dictated by their low intrinsic permeability across the cell membrane, where the efflux transporter, Bcrp, plays a relatively minor role. Both genetic ablation and pharmacological inhibition of Bcrp decreased the systemic clearance of both luciferase substrates, significantly increasing exposure in the blood and, hence, in organs and tissues. These data also indicate that the biodistribution of luciferase substrates can be differentially influenced in luciferase-bearing tissues, leading to a "tissue-dependent" BLI signal. The results of this study point to the need to consider multiple mechanisms that influence the distribution of luciferase substrates. SIGNIFICANCE STATEMENT: Bioluminescence is used to monitor many biological processes, including tumor growth. This study examined the pharmacokinetics, brain distribution, and the role of active efflux transporters on the luciferase substrates D-luciferin and CycLuc1. CycLuc1 has a more sustained systemic circulation time (longer half-life) that can provide an advantage for the superior imaging outcome of CycLuc1 over D-luciferin. The disparity in imaging intensities between brain and peripheral sites is due to low intrinsic permeability of these luciferase substrates across the blood-brain barrier.
Asunto(s)
Neoplasias Encefálicas , Mediciones Luminiscentes , Transportador de Casetes de Unión a ATP, Subfamilia G, Miembro 2/genética , Transportador de Casetes de Unión a ATP, Subfamilia G, Miembro 2/metabolismo , Neoplasias Encefálicas/diagnóstico por imagen , Humanos , Luciferasas/metabolismo , Luciferasas de Luciérnaga/genética , Luciferasas de Luciérnaga/metabolismo , Mediciones Luminiscentes/métodos , Proteínas de Neoplasias/metabolismo , Distribución TisularRESUMEN
The effective treatment of brain tumors is a considerable challenge in part because of the presence of the blood-brain barrier (BBB) that limits drug delivery. Glioblastoma multiforme (GBM) is an aggressive and infiltrative primary brain tumor with an extremely poor prognosis after standard-of-care therapy with surgery, radiotherapy (RT), and chemotherapy. DNA damage response (DDR) pathways play a critical role in DNA repair in cancer cells, and inhibition of these pathways can potentially augment RT and chemotherapy tumor cell toxicity. The ataxia telangiectasia and Rad3-related protein (ATR) kinase is a key regulator of the DDR network and is potently and selectively inhibited by the ATR inhibitor berzosertib. Although in vitro studies demonstrate a synergistic effect of berzosertib in combination with temozolomide, in vivo efficacy studies have yet to recapitulate this observation using intracranial tumor models. In the current study, we demonstrate that delivery of berzosertib to the brain is restricted by efflux at the BBB. Berzosertib has a high binding affinity to brain tissue compared with plasma, thereby leading to low free drug concentrations in the brain. Berzosertib distribution is heterogenous within the tumor, wherein concentrations are substantially lower in normal brain and invasive tumor rim (wherein the BBB is intact) when compared with those in the tumor core (wherein the BBB is leaky). These results demonstrate that high tissue binding and limited and heterogenous brain distribution of berzosertib may be important factors that influence the efficacy of berzosertib therapy in GBM. SIGNIFICANCE STATEMENT: This study examined the brain delivery and efficacy of berzosertib in patient-derived xenograft models of glioblastoma multiforme (GBM). Berzosertib is actively effluxed at the blood-brain barrier and is highly bound to brain tissue, leading to low free drug concentrations in the brain. Berzosertib is heterogeneously distributed into different regions of the brain and tumor and, in this study, was not efficacious in vivo when combined with temozolomide. These factors inform the future clinical utility of berzosertib for GBM.
Asunto(s)
Encéfalo/metabolismo , Glioblastoma/metabolismo , Isoxazoles/administración & dosificación , Isoxazoles/metabolismo , Pirazinas/administración & dosificación , Pirazinas/metabolismo , Animales , Proteínas de la Ataxia Telangiectasia Mutada/antagonistas & inhibidores , Proteínas de la Ataxia Telangiectasia Mutada/metabolismo , Encéfalo/efectos de los fármacos , Línea Celular Tumoral , Femenino , Glioblastoma/tratamiento farmacológico , Células HEK293 , Humanos , Bombas de Infusión , Masculino , Ratones , Ratones Noqueados , Ratones Desnudos , Ensayos Antitumor por Modelo de Xenoinjerto/métodosRESUMEN
In our previous work, PC-9-Br, a PC-9 brain seeking line established via a preclinical animal model of lung cancer brain metastasis (LCBM), exhibited not only resistance to epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) gefitinib in vitro, but also chemotherapy regimens of cisplatin plus etoposide in vivo. Using this cell line, we investigated novel potential targeted therapeutics for treating LCBM in vitro and in vivo to combat drug resistance. Significant increases in mRNA and protein expression levels of Bcl-2 were found in PC-9-Br compared with parental PC-9 (PC-9-P), but no significant changes of Bcl-XL were observed. A remarkable synergistic effect between EGFR-TKI gefitinib and Bcl-2 inhibitors ABT-263 (0.17 ± 0.010 µM at 48 h and 0.02 ± 0.004 µM at 72 h), or ABT-199 (0.22 ± 0.008 µM at 48 h and 0.02 ± 0.001 µM at 72 h) to overcome acquired resistance to gefitinib (> 0.5 µM at 48 h and 0.10 ± 0.007 µM at 72 h) in PC-9-Br was observed in MTT assays. AZD9291 was also shown to overcome acquired resistance to gefitinib in PC-9-Br in MTT assays (0.23 ± 0.031 µM at 48 h and 0.03 ± 0.008 µM at 72 h). Western blot showed significantly decreased phospho-Erk1/2 and increased cleaved-caspase-3 expressions were potential synergistic mechanisms for gefitinib + ABT263/ABT199 in PC-9-Br. Significantly decreased protein expressions of phospho-EGFR, phospho-Akt, p21, and survivin were specific synergistic mechanism for gefitinib + ABT199 in PC-9-Br. In vivo studies demonstrated afatinib (30 mg/kg) and AZD9291 (25 mg/kg) could significantly reduce the LCBM in vivo and increase survival percentages of treated mice compared with mice treated with vehicle and gefitinib (6.25 mg/kg). In conclusion, our study demonstrated gefitinib + ABT263/ABT199, afatinib, and AZD9291 have clinical potential to treat LCBM.
Asunto(s)
Antineoplásicos/uso terapéutico , Neoplasias Encefálicas/secundario , Resistencia a Antineoplásicos/efectos de los fármacos , Gefitinib/uso terapéutico , Acrilamidas/uso terapéutico , Compuestos de Anilina/uso terapéutico , Animales , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Neoplasias Encefálicas/tratamiento farmacológico , Compuestos Bicíclicos Heterocíclicos con Puentes/uso terapéutico , Línea Celular Tumoral , Femenino , Neoplasias Pulmonares/patología , Ratones , Ratones Desnudos , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Sulfonamidas/uso terapéuticoRESUMEN
BACKGROUND: Cancer metastasis and drug resistance have traditionally been studied separately, though these two lethal pathological phenomena almost always occur concurrently. Brain metastasis occurs in a large proportion of lung cancer patients (~ 30%). Once diagnosed, patients have a poor prognosis surviving typically less than 1 year due to lack of treatment efficacy. METHODS: Human metastatic lung cancer cells (PC-9-Br) were injected into the left cardiac ventricle of female athymic nude mice. Brain lesions were allowed to grow for 21 days, animals were then randomized into treatment groups and treated until presentation of neurological symptoms or when moribund. Prior to tissue collection mice were injected with Oregon Green and 14C-Aminoisobutyric acid followed by an indocyanine green vascular washout. Tracer accumulation was determined by quantitative fluorescent microscopy and quantitative autoradiography. Survival was tracked and tumor burden was monitored via bioluminescent imaging. Extent of mutation differences and acquired resistance was measured in-vitro through half-maximal inhibitory assays and qRT-PCR analysis. RESULTS: A PC-9 brain seeking line (PC-9-Br) was established. Mice inoculated with PC-9-Br resulted in a decreased survival time compared with mice inoculated with parental PC-9. Non-targeted chemotherapy with cisplatin and etoposide (51.5 days) significantly prolonged survival of PC-9-Br brain metastases in mice compared to vehicle control (42 days) or cisplatin and pemetrexed (45 days). Further in-vivo imaging showed greater tumor vasculature in mice treated with cisplatin and etoposide compared to non-tumor regions, which was not observed in mice treated with vehicle or cisplatin and pemetrexed. More importantly, PC-9-Br showed significant resistance to gefitinib by in-vitro MTT assays (IC50 > 2.5 µM at 48 h and 0.1 µM at 72 h) compared with parental PC-9 (IC50: 0.75 µM at 48 h and 0.027 µM at 72 h). Further studies on the molecular mechanisms of gefitinib resistance revealed that EGFR and phospho-EGFR were significantly decreased in PC-9-Br compared with PC-9. Expression of E-cadherin and vimentin did not show EMT in PC-9-Br compared with parental PC-9, and PC-9-Br had neither a T790M mutation nor amplifications of MET and HER2 compared with parental PC-9. CONCLUSION: Our study demonstrated that brain metastases of lung cancer cells may independently prompt drug resistance without drug treatment.
Asunto(s)
Antineoplásicos/uso terapéutico , Neoplasias Encefálicas/secundario , Resistencia a Antineoplásicos , Neoplasias Pulmonares/patología , Animales , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Neoplasias Encefálicas/tratamiento farmacológico , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/fisiopatología , Línea Celular Tumoral , Cisplatino/uso terapéutico , Receptores ErbB/genética , Etopósido/uso terapéutico , Femenino , Gefitinib/uso terapéutico , Regulación Neoplásica de la Expresión Génica , Humanos , Ratones , Ratones Desnudos , Pemetrexed/uso terapéutico , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Targeted inhibition of RAF and MEK by molecularly targeted agents has been employed as a strategy to block aberrant mitogen-activated protein kinase (MAPK) signaling in melanoma. While the use of BRAF and MEK inhibitors, either as a single agent or in combination, improved efficacy in BRAF-mutant melanoma, initial responses are often followed by relapse due to acquired resistance. Moreover, some BRAF inhibitors are associated with paradoxical activation of the MAPK pathway, causing the development of secondary malignancies. The use of panRAF inhibitors, i.e., those that target all isoforms of RAF, may overcome paradoxical activation and resistance. The purpose of this study was to perform a quantitative assessment and evaluation of the influence of efflux mechanisms at the blood-brain barrier (BBB), in particular, Abcb1/P-glycoprotein (P-gp) and Abcg2/breast cancer resistance protein (Bcrp), on the brain distribution of three panRAF inhibitors: CCT196969 [1-(3-(tert-butyl)-1-phenyl-1H-pyrazol-5-yl)-3-(2-fluoro-4-((3-oxo-3,4-dihydropyrido[2,3-b]pyrazin-8-yl)oxy)phenyl)urea], LY3009120 1-(3,3-Dimethylbutyl)-3-(2-fluoro-4-methyl-5-(7-methyl-2-(methylamino)pyrido(2,3-d)pyrimidin-6-yl)phenyl)urea, and MLN2480 [4-pyrimidinecarboxamide, 6-amino-5-chloro-N-[(1R)-1-[5-[[[5-chloro-4-(trifluoromethyl)-2-pyridinyl]amino]carbonyl]-2-thiazolyl]ethyl]-]. In vitro studies using transfected Madin-Darby canine kidney II cells indicate that only LY3009120 and MLN2480 are substrates of Bcrp, and none of the three inhibitors are substrates of P-gp. The three panRAF inhibitors show high nonspecific binding in brain and plasma. In vivo studies in mice show that the brain distribution of CCT196969, LY3009120, and MLN2480 is limited, and is enhanced in transgenic mice lacking P-gp and Bcrp. While MLN2480 has a higher brain distribution, LY3009120 exhibits superior in vitro efficacy in patient-derived melanoma cell lines. The delivery of a drug to the site of action residing behind a functionally intact BBB, along with drug potency against the target, collectively play a critical role in determining in vivo efficacy outcomes.
Asunto(s)
Neoplasias Encefálicas/metabolismo , Encéfalo/metabolismo , Compuestos Heterocíclicos con 3 Anillos/metabolismo , Melanoma/metabolismo , Compuestos de Fenilurea/metabolismo , Pirazinas/metabolismo , Pirimidinas/metabolismo , Animales , Encéfalo/efectos de los fármacos , Neoplasias Encefálicas/tratamiento farmacológico , Neoplasias Encefálicas/secundario , Línea Celular Tumoral , Perros , Relación Dosis-Respuesta a Droga , Femenino , Compuestos Heterocíclicos con 3 Anillos/administración & dosificación , Humanos , Células de Riñón Canino Madin Darby , Masculino , Melanoma/tratamiento farmacológico , Ratones , Ratones Noqueados , Compuestos de Fenilurea/administración & dosificación , Proteínas de Unión a Fosfatidiletanolamina/antagonistas & inhibidores , Proteínas de Unión a Fosfatidiletanolamina/metabolismo , Pirazinas/administración & dosificación , Pirimidinas/administración & dosificaciónRESUMEN
Tyrosine kinase inhibitors that target the epidermal growth factor receptor (EGFR) have had success in treating EGFR-positive tumors, including non-small-cell lung cancer (NSCLC). However, developing EGFR inhibitors that can be delivered to the brain remains a challenge. To identify optimal compounds for brain delivery, eight EGFR inhibitors [afatinib, 6-[4-[(4-ethylpiperazin-1-yl)methyl]phenyl]-N-(1-phenylethyl)-7H-pyrrolo[2,3-day]pyrimidin-4-amine (AEE788), [4-(3-chloro-2-fluoroanilino)-7-methoxyquinazolin-6-yl] (2R)-2,4-dimethylpiperazine-1-carboxylate (AZD3759), erlotinib, dacomitinib, gefitinib, osimertinib, and vandetanib] were evaluated for distributional kinetics using cassette dosing with the ultimate goal of understanding the brain penetrability of compounds that share the same molecular target in an important oncogenic signaling pathway for both primary brain tumors (glioblastoma) and brain metastases (e.g., NSCLC). Cassette dosing was validated by comparing the brain-to-plasma ratios obtained from cassette-dosing to discrete-dosing studies. The brain-to-blood partition coefficients (Kp,brain) were calculated following cassette dosing of the eight EGFR inhibitors. The comparison of Kp,brain in wild-type and transporter-deficient mice confirmed that two major efflux transporters at the blood-brain barrier (BBB), P-glycoprotein and breast cancer resistance protein, play a crucial role in the brain distribution of seven out of eight EGFR inhibitors. Results show that the prediction of brain distribution based on physicochemical properties of a drug can be misleading, especially for compounds subject to extensive efflux transport. Moreover, this study informs the choice of EGFR inhibitors, i.e., determining BBB permeability combined with a known target potency, that may be effective in future clinical trials for brain tumors.
Asunto(s)
Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/metabolismo , Transportador de Casetes de Unión a ATP, Subfamilia G, Miembro 2/metabolismo , Encéfalo/metabolismo , Receptores ErbB/antagonistas & inhibidores , Receptores ErbB/metabolismo , Inhibidores de Proteínas Quinasas/metabolismo , Transportadoras de Casetes de Unión a ATP/metabolismo , Animales , Barrera Hematoencefálica/metabolismo , Femenino , Glioblastoma/metabolismo , Masculino , Ratones , Inhibidores de Proteínas Quinasas/farmacología , Transducción de Señal/efectos de los fármacosRESUMEN
BACKGROUND: Brain tumor vasculature can be significantly compromised and leakier than that of normal brain blood vessels. Little is known if there are vascular permeability alterations in the brain adjacent to tumor (BAT). Changes in BAT permeability may also lead to increased drug permeation in the BAT, which may exert toxicity on cells of the central nervous system. Herein, we studied permeation changes in BAT using quantitative fluorescent microscopy and autoradiography, while the effect of chemotherapy within the BAT region was determined by staining for activated astrocytes. METHODS: Human metastatic breast cancer cells (MDA-MB-231Br) were injected into left ventricle of female NuNu mice. Metastases were allowed to grow for 28 days, after which animals were injected fluorescent tracers Texas Red (625 Da) or Texas Red dextran (3 kDa) or a chemotherapeutic agent 14C-paclitaxel. The accumulation of tracers and 14C-paclitaxel in BAT were determined by using quantitative fluorescent microscopy and autoradiography respectively. The effect of chemotherapy in BAT was determined by staining for activated astrocytes. RESULTS: The mean permeability of texas Red (625 Da) within BAT region increased 1.0 to 2.5-fold when compared to normal brain, whereas, Texas Red dextran (3 kDa) demonstrated mean permeability increase ranging from 1.0 to 1.8-fold compared to normal brain. The Kin values in the BAT for both Texas Red (625 Da) and Texas Red dextran (3 kDa) were found to be 4.32 ± 0.2 × 105 mL/s/g and 1.6 ± 1.4 × 105 mL/s/g respectively and found to be significantly higher than the normal brain. We also found that there is significant increase in accumulation of 14C-Paclitaxel in BAT compared to the normal brain. We also observed animals treated with chemotherapy (paclitaxel (10 mg/kg), erubilin (1.5 mg/kg) and docetaxel (10 mg/kg)) showed activated astrocytes in BAT. CONCLUSIONS: Our data showed increased permeation of fluorescent tracers and 14C-paclitaxel in the BAT. This increased permeation lead to elevated levels of activated astrocytes in BAT region in the animals treated with chemotherapy.
Asunto(s)
Neoplasias Encefálicas/patología , Encéfalo/patología , Neoplasias de la Mama/patología , Animales , Barrera Hematoencefálica/patología , Encéfalo/efectos de los fármacos , Neoplasias Encefálicas/tratamiento farmacológico , Neoplasias de la Mama/tratamiento farmacológico , Línea Celular Tumoral , Femenino , Humanos , Ratones , Ratones Desnudos , Modelos Teóricos , Paclitaxel/farmacología , PermeabilidadRESUMEN
In women, breast cancer is the most common cancer diagnosis and second most common cause of cancer death. More than half of breast cancer patients will develop metastases to the bone, liver, lung, or brain. Breast cancer brain metastases (BCBM) confers a poor prognosis, as current therapeutic options of surgery, radiation, and chemotherapy rarely significantly extend life and are considered palliative. Within the realm of chemotherapy, the last decade has seen an explosion of novel chemotherapeutics involving targeting agents and unique dosage forms. We provide a historical overview of BCBM chemotherapy, review the mechanisms of new agents such as poly-ADP ribose polymerase inhibitors, cyclin-dependent kinase 4/6 inhibitors, phosphatidyl inositol 3-kinaseinhibitors, estrogen pathway antagonists for hormone-receptor positive BCBM; tyrosine kinase inhibitors, antibodies, and conjugates for HER2+ BCBM; repurposed cytotoxic chemotherapy for triple negative BCBM; and the utilization of these new agents and formulations in ongoing clinical trials. The mechanisms of novel dosage formulations such as nanoparticles, liposomes, pegylation, the concepts of enhanced permeation and retention, and drugs utilizing these concepts involved in clinical trials are also discussed. These new treatments provide a promising outlook in the treatment of BCBM.
Asunto(s)
Antineoplásicos/uso terapéutico , Neoplasias Encefálicas/tratamiento farmacológico , Neoplasias de la Mama/tratamiento farmacológico , Animales , Antineoplásicos/administración & dosificación , Antineoplásicos/farmacocinética , Barrera Hematoencefálica/metabolismo , Neoplasias Encefálicas/epidemiología , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/secundario , Neoplasias de la Mama/epidemiología , Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/patología , Sistemas de Liberación de Medicamentos , HumanosRESUMEN
PURPOSE: The blood-tumor barrier (BTB) limits irinotecan distribution in tumors of the central nervous system. However, given that the BTB has increased passive permeability we hypothesize that liposomal irinotecan would improve local exposure of irinotecan and its active metabolite SN-38 in brain metastases relative to conventional irinotecan due to enhanced-permeation and retention (EPR) effect. METHODS: Female nude mice were intracardially or intracranially implanted with human brain seeking breast cancer cells (brain metastases of breast cancer model). Mice were administered vehicle, non-liposomal irinotecan (50 mg/kg), liposomal irinotecan (10 mg/kg and 50 mg/kg) intravenously starting on day 21. Drug accumulation, tumor burden, and survival were evaluated. RESULTS: Liposomal irinotecan showed prolonged plasma drug exposure with mean residence time (MRT) of 17.7 ± 3.8 h for SN-38, whereas MRT was 3.67 ± 1.2 for non-liposomal irinotecan. Further, liposomal irinotecan accumulated in metastatic lesions and demonstrated prolonged exposure of SN-38 compared to non-liposomal irinotecan. Liposomal irinotecan achieved AUC values of 6883 ± 4149 ng-h/g for SN-38, whereas non-liposomal irinotecan showed significantly lower AUC values of 982 ± 256 ng-h/g for SN-38. Median survival for liposomal irinotecan was 50 days, increased from 37 days (p<0.05) for vehicle. CONCLUSIONS: Liposomal irinotecan accumulates in brain metastases, acts as depot for sustained release of irinotecan and SN-38, which results in prolonged survival in preclinical model of breast cancer brain metastasis.
Asunto(s)
Neoplasias Encefálicas/tratamiento farmacológico , Encéfalo/metabolismo , Irinotecán/farmacocinética , Inhibidores de Topoisomerasa I/farmacocinética , Neoplasias de la Mama Triple Negativas/patología , Animales , Encéfalo/patología , Neoplasias Encefálicas/mortalidad , Neoplasias Encefálicas/secundario , Línea Celular Tumoral , Femenino , Humanos , Inyecciones Intravenosas , Irinotecán/uso terapéutico , Liposomas , Ratones , Ratones Desnudos , Nanopartículas , Permeabilidad , Distribución Tisular , Inhibidores de Topoisomerasa I/uso terapéutico , Resultado del Tratamiento , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
BACKGROUND: Brain metastases are an increasing problem in women with invasive breast cancer. Strategies designed to treat brain metastases of breast cancer, particularly chemotherapeutics such as irinotecan, demonstrate limited efficacy. Conventional irinotecan distributes poorly to brain metastases; therefore, NKTR-102, a PEGylated irinotecan conjugate should enhance irinotecan and its active metabolite SN38 exposure in brain metastases leading to brain tumor cytotoxicity. METHODS: Female nude mice were intracranially or intracardially implanted with human brain seeking breast cancer cells (MDA-MB-231Br) and dosed with irinotecan or NKTR-102 to determine plasma and tumor pharmacokinetics of irinotecan and SN38. Tumor burden and survival were evaluated in mice treated with vehicle, irinotecan (50 mg/kg), or NKTR-102 low and high doses (10 mg/kg, 50 mg/kg respectively). RESULTS: NKTR-102 penetrates the blood-tumor barrier and distributes to brain metastases. NKTR-102 increased and prolonged SN38 exposure (>20 ng/g for 168 h) versus conventional irinotecan (>1 ng/g for 4 h). Treatment with NKTR-102 extended survival time (from 35 days to 74 days) and increased overall survival for NKTR-102 low dose (30 % mice) and NKTR-102 high dose (50 % mice). Tumor burden decreased (37 % with 10 mg/kg NKTR-102 and 96 % with 50 mg/kg) and lesion sizes decreased (33 % with 10 mg/kg NKTR-102 and 83 % with 50 mg/kg NKTR-102) compared to conventional irinotecan treated animals. CONCLUSIONS: Elevated and prolonged tumor SN38 exposure after NKTR-102 administration appears responsible for increased survival in this model of breast cancer brain metastasis. Further, SN38 concentrations observed in this study are clinically achieved with 145 mg/m(2) NKTR-102, such as those used in the BEACON trial, underlining translational relevance of these results.
Asunto(s)
Antineoplásicos Fitogénicos/farmacología , Neoplasias Encefálicas/patología , Neoplasias Encefálicas/secundario , Neoplasias de la Mama/patología , Camptotecina/análogos & derivados , Animales , Antineoplásicos Fitogénicos/administración & dosificación , Antineoplásicos Fitogénicos/química , Barrera Hematoencefálica/efectos de los fármacos , Barrera Hematoencefálica/metabolismo , Encéfalo/efectos de los fármacos , Encéfalo/metabolismo , Neoplasias Encefálicas/tratamiento farmacológico , Neoplasias Encefálicas/mortalidad , Camptotecina/administración & dosificación , Camptotecina/química , Camptotecina/farmacología , Línea Celular Tumoral , Modelos Animales de Enfermedad , Monitoreo de Drogas , Femenino , Humanos , Irinotecán , Mediciones Luminiscentes , Ratones , Estructura Molecular , Permeabilidad , Carga Tumoral/efectos de los fármacos , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Capsaicin (CP), a recent FDA-approved drug for the topical treatment of neuropathic pain, is associated with several side effects like irritation, burning sensation, and erythema, resulting in poor patient compliance. The present study is an attempt to study the effect of CP encasement in nano-lipoidal carriers (NLCs) on skin-transport characteristics, in vivo pharmacological performance, skin compliance, and stability of the finished product. The study also compares two methods of NLC preparation, namely microemulsification and rotary-evaporation for various attributes. The results demonstrated that microemulsion technique produced smaller nanoparticles vis-à-vis the rotary-evaporation method. Out of the various studied solid lipids, NLCs from stearic acid offered smallest size and the highest negative zeta potential. The NLC-gel offered higher skin permeation and skin retention of CP across LACA mice skin as compared with the conventional cream. The analgesic effect was observed to be enhanced substantially than that of the conventional cream when tested on a radiant mouse tail-flick model. The most alarming problems of skin-irritation and redness were successfully taken care by NLC-gel while the mice group receiving conventional cream showed marked changes in the skin histopathology. Besides the enhanced efficacy and decreased skin-irritation, the developed CP-NLCs also found to be stable and rheologically accepted formulation for the treatment of pain-associated disorders.
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Analgésicos no Narcóticos/administración & dosificación , Capsaicina/administración & dosificación , Portadores de Fármacos/administración & dosificación , Nanoestructuras/química , Administración Cutánea , Analgésicos no Narcóticos/efectos adversos , Analgésicos no Narcóticos/metabolismo , Analgésicos no Narcóticos/uso terapéutico , Animales , Capsaicina/efectos adversos , Capsaicina/metabolismo , Capsaicina/uso terapéutico , Coloides , Portadores de Fármacos/efectos adversos , Portadores de Fármacos/metabolismo , Portadores de Fármacos/uso terapéutico , Composición de Medicamentos , Femenino , Técnicas In Vitro , Liposomas , Ratones , Piel/efectos de los fármacos , Piel/metabolismo , Absorción CutáneaRESUMEN
PURPOSE: This article describes the clinical development bridging strategy and key data to support the marketing application of the risankizumab on-body injection (OBI) system for the treatment of moderately to severely active Crohn's disease (CD), even though the OBI was not evaluated directly in the pivotal Phase III studies in CD. METHODS: Three studies were conducted as part of the clinical bridging strategy. The pilot pharmacokinetics (PK) study was a Phase I, single-dose, 4-arm, open-label, randomized, parallel-group exploratory PK and tolerability study that assessed the effect of rate and volume of administration on the bioavailability (BA) of risankizumab and the extent of injection site-related pain after subcutaneous (SC) administration in healthy subjects. The pivotal BA/bioequivalence (BE) study was a relative BA/BE bridging study in healthy subjects to assess the relative BA of the to-be-marketed risankizumab OBI compared with the prefilled syringe (PFS) used in the Phase III CD studies. The OBI adhesive study was a randomized, open-label, non-drug interventional study in healthy subjects to assess the OBI adhesive effectiveness and skin tolerability at 2 different locations (abdomen and upper thigh) over different periods of time (5 and 30 minutes). FINDINGS: The pilot PK study showed that risankizumab exposures were similar across different rates/volumes of SC administration in healthy subjects, thereby supporting further development of the OBI. Second, a pivotal BA/BE study showed comparability between the OBI and Phase III PFS with bioequivalent risankizumab AUCs and no clinically meaningful difference for Cmax based on the wide therapeutic window of risankizumab. In both studies, no new safety risks were identified. No impact of immunogenicity on PK profile or safety was observed for the OBI. Third, an adhesive OBI (without risankizumab) study showed that there were no differences in adhesion/skin tolerability observed over time (up to 30 minutes) or for location of adhesion, and the OBI device adhesion was well tolerated at both the abdomen and thigh locations. IMPLICATIONS: These results supported the risankizumab OBI presentation approval in CD.
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Enfermedad de Crohn , Humanos , Enfermedad de Crohn/tratamiento farmacológico , Jeringas , Inyecciones Subcutáneas , Anticuerpos Monoclonales/uso terapéuticoRESUMEN
Inhibitors of the mitotic kinesin Kif11 are anti-mitotics that, unlike vinca alkaloids or taxanes, do not disrupt microtubules and are not neurotoxic. However, development of resistance has limited their clinical utility. While resistance to Kif11 inhibitors in other cell types is due to mechanisms that prevent these drugs from disrupting mitosis, we find that in glioblastoma (GBM), resistance to the Kif11 inhibitor ispinesib works instead through suppression of apoptosis driven by activation of STAT3. This form of resistance requires dual phosphorylation of STAT3 residues Y705 and S727, mediated by SRC and epidermal growth factor receptor (EGFR), respectively. Simultaneously inhibiting SRC and EGFR reverses this resistance, and combined targeting of these two kinases in vivo with clinically available inhibitors is synergistic and significantly prolongs survival in ispinesib-treated GBM-bearing mice. We thus identify a translationally actionable approach to overcoming Kif11 inhibitor resistance that may work to block STAT3-driven resistance against other anti-cancer therapies as well.
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Antimitóticos , Glioblastoma , Animales , Antimitóticos/farmacología , Línea Celular Tumoral , Receptores ErbB/metabolismo , Glioblastoma/tratamiento farmacológico , Glioblastoma/metabolismo , Cinesinas , Ratones , Factor de Transcripción STAT3/metabolismo , Transducción de SeñalRESUMEN
INTRODUCTION/PURPOSE: The objective of this research was to characterize the impact of Roux-en-Y gastric bypass (RYGB) on the pharmacokinetic properties of the pro-drug lisdexamfetamine and its active metabolite, d-amphetamine. MATERIALS AND METHODS: A case-control design was used where patients who had undergone RYGB 9-24 months prior were matched on sex, age, and body mass index (BMI) to nonsurgical controls who had no history of weight loss surgery. Each participant received a single 50 mg dose of lisdexamfetamine, and plasma samples were collected over a 24-h period following dosing. Noncompartmental analyses were used to compare pharmacokinetic measures between groups. RESULTS: There were no significant differences between the RYGB (n = 10) and NSC groups (n = 10) on sex (70% female), age (40.9 ± 9.6 vs. 41.3 ± 8.9 years), BMI (30.3 ± 5.2 vs. 31 ± 5.9 kg/m2), or ethnicity (100% vs. 80% White). The pharmacokinetic parameters between the RYGB and NCS groups were found to be equivalent for lisdexamfetamine and d-amphetamine, including maximum plasma concentration (Cmax), time to maximum plasma concentration (Tmax), and area under the plasma concentration-time curve (AUC(0-∞)). CONCLUSION: These data suggest that there is no need to routinely adjust lisdexamfetamine dosing following RYGB. However, given the potential for inter-individual differences, patients who undergo RYGB should be clinically monitored and individualized dosing strategies should be considered for concerns surrounding efficacy or toxicity.
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Derivación Gástrica , Obesidad Mórbida , Índice de Masa Corporal , Estudios de Casos y Controles , Femenino , Humanos , Dimesilato de Lisdexanfetamina , Masculino , Obesidad Mórbida/cirugía , Estudios RetrospectivosRESUMEN
Glioblastoma, the most lethal primary brain cancer, is extremely proliferative and invasive. Tumor cells at tumor/brain-interface often exist behind a functionally intact blood-brain barrier (BBB), and so are shielded from exposure to therapeutic drug concentrations. An ideal glioblastoma treatment needs to engage targets that drive proliferation as well as invasion, with brain penetrant therapies. One such target is the mitotic kinesin KIF11, which can be inhibited with ispinesib, a potent molecularly-targeted drug. Although, achieving durable brain exposures of ispinesib is critical for adequate tumor cell engagement during mitosis, when tumor cells are vulnerable, for efficacy. Our results demonstrate that the delivery of ispinesib is restricted by P-gp and Bcrp efflux at BBB. Thereby, ispinesib distribution is heterogeneous with concentrations substantially lower in invasive tumor rim (intact BBB) compared to glioblastoma core (disrupted BBB). We further find that elacridar-a P-gp and Bcrp inhibitor-improves brain accumulation of ispinesib, resulting in remarkably reduced tumor growth and extended survival in a rodent model of glioblastoma. Such observations show the benefits and feasibility of pairing a potentially ideal treatment with a compound that improves its brain accumulation, and supports use of this strategy in clinical exploration of cell cycle-targeting therapies in brain cancers.
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Transportador de Casetes de Unión a ATP, Subfamilia G, Miembro 2/genética , Benzamidas/farmacología , Proliferación Celular/efectos de los fármacos , Cinesinas/antagonistas & inhibidores , Proteínas de Neoplasias/genética , Quinazolinas/farmacología , Subfamilia B de Transportador de Casetes de Unión a ATP/antagonistas & inhibidores , Subfamilia B de Transportador de Casetes de Unión a ATP/genética , Transportador de Casetes de Unión a ATP, Subfamilia G, Miembro 2/antagonistas & inhibidores , Acridinas/química , Acridinas/farmacología , Animales , Barrera Hematoencefálica/efectos de los fármacos , Encéfalo , Línea Celular Tumoral , Modelos Animales de Enfermedad , Glioblastoma/genética , Glioblastoma/patología , Humanos , Cinesinas/genética , Ratones , Terapia Molecular Dirigida , Invasividad Neoplásica/genética , Invasividad Neoplásica/patología , Proteínas de Neoplasias/antagonistas & inhibidores , Tetrahidroisoquinolinas/química , Tetrahidroisoquinolinas/farmacología , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
OBJECTIVE: Chemotherapy infusions directly into the fourth ventricle may play a role in treating malignant fourth-ventricular tumors. This study tested the safety and pharmacokinetics of short-term and long-term administration of MTX110 (soluble panobinostat; Midatech Pharma) into the fourth ventricle of nonhuman primates. METHODS: Four rhesus macaque monkeys underwent posterior fossa craniectomy and catheter insertion into the fourth ventricle. In group I (n = 2), catheters were externalized and lumbar drain catheters were placed simultaneously to assess CSF distribution after short-term infusions. MTX110 (0.5 ml of 300 µM panobinostat solution) was infused into the fourth ventricle daily for 5 consecutive days. Serial CSF and serum panobinostat levels were measured. In group II (n = 2), fourth-ventricle catheters were connected to a subcutaneously placed port for subsequent long-term infusions. Four cycles of MTX110, each consisting of 5 daily infusions (0.5 ml of 300 µM panobinostat solution), were administered over 8 weeks. Animals underwent detailed neurological evaluations, MRI scans, and postmortem histological analyses. RESULTS: No neurological deficits occurred after intraventricular MTX110 infusions. MRI scans showed catheter placement within the fourth ventricle in all 4 animals, with extension to the cerebral aqueduct in 1 animal and into the third ventricle in 1 animal. There were no MRI signal changes in the brainstem, cerebellum, or elsewhere in the brains of any of the animals. Histologically, normal brain cytoarchitecture was preserved with only focal mild postsurgical changes in all animals. Panobinostat was undetectable in serum samples collected 2 and 4 hours after infusions in all samples in both groups. In group I, the mean peak panobinostat level in the fourth-ventricle CSF (6242 ng/ml) was significantly higher than that in the lumbar CSF (9 ng/ml; p < 0.0001). In group II, the mean peak CSF panobinostat level (11,042 ng/ml) was significantly higher than the mean trough CSF panobinostat level (33 ng/ml; p < 0.0001). CONCLUSIONS: MTX110 can be safely infused into the fourth ventricle in nonhuman primates at supratherapeutic doses. Postinfusion CSF panobinostat levels peak immediately in the fourth ventricle and then rapidly decrease over 24 hours. Panobinostat is detectable at low levels in CSF measured from the lumbar cistern up to 4 hours after infusions. These results will provide background data for a pilot clinical trial in patients with recurrent medulloblastoma.
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Sepsis is a systemic inflammatory disease resulting from an infection. This disorder affects 750 000 people annually in the United States and has a 62% rehospitalization rate. Septic symptoms range from typical flu-like symptoms (eg, headache, fever) to a multifactorial syndrome known as sepsis-associated encephalopathy (SAE). Patients with SAE exhibit an acute altered mental status and often have higher mortality and morbidity. In addition, many sepsis survivors are also burdened with long-term cognitive impairment. The mechanisms through which sepsis initiates SAE and promotes long-term cognitive impairment in septic survivors are poorly understood. Due to its unique role as an interface between the brain and the periphery, numerous studies support a regulatory role for the blood-brain barrier (BBB) in the progression of acute and chronic brain dysfunction. In this review, we discuss the current body of literature which supports the BBB as a nexus which integrates signals from the brain and the periphery in sepsis. We highlight key insights on the mechanisms that contribute to the BBB's role in sepsis which include neuroinflammation, increased barrier permeability, immune cell infiltration, mitochondrial dysfunction, and a potential barrier role for tissue non-specific alkaline phosphatase (TNAP). Finally, we address current drug treatments (eg, antimicrobials and intravenous immunoglobulins) for sepsis and their potential outcomes on brain function. A comprehensive understanding of these mechanisms may enable clinicians to target specific aspects of BBB function as a therapeutic tool to limit long-term cognitive impairment in sepsis survivors.
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Compounds based on the isoxazoline moiety were screened for their antimycobacterial activity in vitro against Mycobacterium tuberculosis H37R (MTB), and INH (isoniazid) resistant Mycobacterium tuberculosis (INHR-MTB) using the agar dilution method and bactec 460. Among the synthesized compounds, 4-[5-(4-bromophenyl)-4,5-dihydro-3-isoxazolyl]-2-methylphenol (4l) was found to be the most active agent against MTB and INHR-MTB with minimum inhibitory concentration of 0.62 microM. When compared to INH, compound (4l) was 1.12 fold and 3.0 fold more active against MTB and INHR-MTB, respectively.
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Antituberculosos/química , Mycobacterium tuberculosis/efectos de los fármacos , Oxazoles/farmacología , Antituberculosos/farmacología , Farmacorresistencia Bacteriana Múltiple/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Oxazoles/química , Relación Estructura-ActividadRESUMEN
Tumors residing in the central nervous system (CNS) compromise the blood-brain barrier (BBB) via increased vascular permeability, with the magnitude of changes dependent on the tumor type and location. Current studies determine penetrability of a cancer therapeutic by administering progressively larger molecules until cutoff is observed where little to no tumor accumulation occurs. However, decades-old experimental work and mathematical modeling document methods to calculate both the size of the vascular opening (pore) with solute permeability values. In this study, we updated this classic mathematical modeling approach with quantitative fluorescence microscopy in two preclinical tumor models, allowing simultaneous administration of multiple sized tracers to determine vascular permeability at a resolution of nearly one micron. We observed that three molecules ranging from 100 Da to 70 kDa permeated into a preclinical glioblastoma model at rates proportional to their diffusion in water. This suggests the solutes freely diffused from blood to glioma across vascular pores without steric restriction, which calculates to a pore size of >140 nm in diameter. In contrast, the calculated pore size of a brain metastasis of breast cancer was approximately 10-fold smaller than glioma vasculature. This difference explains why antibodies are effective against glioblastoma but generally fail in brain metastases of breast cancer. On the basis of our observations, we hypothesize that trastuzumab most likely fails in the treatment of brain metastases of breast cancer because of poor CNS penetration, while the similar sized antibody bevacizumab is effective in the same tumor type not because it penetrates the CNS degree better, but because it scavenges VEGF in the vascular compartment, which reduces edema and permeation. Cancer Res; 77(2); 238-46. ©2016 AACR.