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PURPOSE: To evaluate the safety, tolerability, pharmacodynamics (PD), and potential efficacy of zosuquidar (Zos) in combination with daunorubicin and cytarabine in elderly patients with newly diagnosed acute myeloid leukemia (AML). METHODS: Patients with AML (N = 106) were treated with Zos as a 72-h continuous intravenous (CIV) infusion along with chemotherapy. Leukemic blasts from the patients were assessed for P-glycoprotein (P-gp) function using ex vivo bioassays for screening and PD analyses. Patient outcomes were categorized according to primary (N = 56) and secondary (N = 50) AML cohorts (pAML and sAML, respectively) and stratified into P-gp-high and P-gp-low subgroups. RESULTS: Patients with P-gp-high blasts exhibited comparable overall remission rates (ORR) to those with P-gp-low blasts in both the pAML and sAML cohorts. The P-gp-high and P-gp-low subgroups in the pAML cohort exhibited similar overall survival (OS). Patients with sAML and P-gp-high blasts exhibited significantly better OS than those in the P-gp-low subgroup. PD analyses revealed that Zos infusion provided 82 h of uninterrupted effective ≥ 90% inhibition of P-gp functional activity in leukemic blasts. CONCLUSIONS: These observations provide evidence of Zos efficacy with the 72-h CIV infusion approach. The similarity of ORR in the P-gp-high and P-gp-low subgroups is consistent with Zos-mediated neutralization of P-gp as verified by PD analyses. The bioassay identified sAML patients most likely to respond favorably to Zos co-therapy indicating feasibility as a Zos companion diagnostic. A follow-up placebo-controlled trial is needed to verify these promising results. GOV IDENTIFIER: NCT00129168; First posted on August 11, 2005.
Asunto(s)
Miembro 1 de la Subfamilia B de Casetes de Unión a ATP , Protocolos de Quimioterapia Combinada Antineoplásica , Citarabina , Daunorrubicina , Leucemia Mieloide Aguda , Humanos , Leucemia Mieloide Aguda/tratamiento farmacológico , Leucemia Mieloide Aguda/patología , Anciano , Masculino , Femenino , Citarabina/administración & dosificación , Daunorrubicina/administración & dosificación , Daunorrubicina/uso terapéutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/metabolismo , Infusiones Intravenosas , Persona de Mediana Edad , Anciano de 80 o más Años , Fenotipo , Dibenzocicloheptenos , QuinolinasRESUMEN
PURPOSE: To evaluate safety, tolerability, potential efficacy, and pharmacodynamics (PD) of zosuquidar (Zos) in combination with gemtuzumab ozogamicin (GO) in elderly patients with relapsed or refractory (RR) acute myeloid leukemia (AML). METHODS: Patients with RR AML (N = 41) were treated with Zos as a 48-h continuous intravenous infusion initiated 4 h prior to a 2-h infusion of GO on days 1 and 15. P-glycoprotein (P-gp) status of the patients' leukemic blasts and PD determinations were assessed with ex vivo bioassays. Patient outcomes were analyzed for the total cohort and as stratified into P-gp-positive (P-gp +) and P-gp-negative (P-gpâ) subgroups. RESULTS: The eligible cohort exhibited a 34% overall remission rate (ORR), a composite of patients that exhibited complete remission (CR), CR with incomplete platelet recovery, or morphologic remission. Patients with 1st relapsed disease exhibited 40% ORR. P-gp phenotype did not significantly predict ORR. However, the P-gp + subgroup exhibited a greater median overall survival (OS) of 6.0 months vs. 1.8 months for patients in the P-gpâ subgroup (p = 0.01). PD analyses revealed 90-95% inhibition of blast P-gp function during Zos infusion. Treatment related toxicities were observed and resolved with decrease or discontinued Zos or GO dosages. CONCLUSIONS: Zos plus GO elicited appreciable ORR for an elderly patient population with RR AML. The greater OS of the P-gp + subgroup vs. the P-gpâ subgroup suggests that patients with P-gp + leukemic blasts were being more effectively targeted by GO with Zos co-therapy. The poorer OS of the P-gpâ subgroup suggests activity of Zos-insensitive multidrug resistant mechanisms. GOV IDENTIFIER: NCT00233909; First posted October 06, 2005.
Asunto(s)
Miembro 1 de la Subfamilia B de Casetes de Unión a ATP , Leucemia Mieloide Aguda , Anciano , Humanos , Gemtuzumab , Subfamilia B de Transportador de Casetes de Unión a ATP , Leucemia Mieloide Aguda/tratamiento farmacológico , Enfermedad Crónica , FenotipoRESUMEN
BACKGROUND: Multidrug resistance (MDR) transporter proteins such as P-glycoprotein (P-gp) efflux a variety of chemotherapeutic drugs from acute myeloid leukemia (AML) blasts leading to clinical drug resistance. METHODS: This study examined heterogeneity of MDR functional efflux by AML blasts using two flow cytometry bioassays. Bone marrow specimens (N = 50) from elderly patients with newly diagnosed AML were analyzed for CD34+ blasts with MDR efflux function. Efflux was measured with a fluorescent dye (DiOC2 ) as a surrogate for oncology drugs that are substrates for MDR efflux. P-gp-mediated efflux was differentiated from non-P-gp MDR activities using zosuquidar, a highly selective P-gp modulator. The bioassays included a zosuquidar-dependent DiOC2 accumulation bioassay that measured only P-gp. The second method, termed the efflux bioassay, could detect P-gp and other non-P-gp efflux depending on bioassay culture conditions. RESULTS: Sixty-two percent of the specimens were considered positive for blasts with P-gp function, and 26% of such P-gp-positive specimens also exhibited zosuquidar-resistant (i.e., non-P-gp) MDR efflux activity; 37% of P-gp-negative AML blast specimens displayed zosuquidar-resistant MDR function in the efflux bioassay. CONCLUSIONS: These results confirm the heterogeneous nature of MDR efflux pumps in AML blasts, and provide support for the hypothesis that non-P-gp MDR contributed to negative results with zosuquidar in AML trials like ECOG-ACRIN E3999. © 2018 International Clinical Cytometry Society.
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Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/metabolismo , Ensayos Clínicos como Asunto , Resistencia a Múltiples Medicamentos , Leucemia Mieloide Aguda/metabolismo , Anciano , Bioensayo , Crisis Blástica/patología , Dibenzocicloheptenos/farmacología , Dibenzocicloheptenos/uso terapéutico , Femenino , Humanos , Leucemia Mieloide Aguda/tratamiento farmacológico , Leucemia Mieloide Aguda/patología , Masculino , Persona de Mediana Edad , Fenotipo , Quinolinas/farmacología , Quinolinas/uso terapéuticoRESUMEN
Neuromyelitis optica (NMO) (and NMO spectrum disorder) is an autoimmune inflammatory disease of the CNS primarily affecting spinal cord and optic nerves. Reliable and sensitive biomarkers for onset, relapse, and progression in NMO are urgently needed because of the heterogeneous clinical presentation, severity of neurologic disability following relapses, and variability of therapeutic response. Detecting aquaporin-4 (AQP4) antibodies (AQP4-IgG or NMO-IgG) in serum supports the diagnosis of seropositive NMO. However, whether AQP4-IgG levels correlate with disease activity, severity, response to therapy, or long-term outcomes is unclear. Moreover, biomarkers for patients with seronegative NMO have yet to be defined and validated. Collaborative international studies hold great promise for establishing and validating biomarkers that are useful in therapeutic trials and clinical management. In this review, we discuss known and potential biomarkers for NMO.
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It is often necessary to adjust for detectable endogenous biomarker levels in spiked validation samples (VS) and in selectivity determinations during bioanalytical method validation for ligand-binding assays (LBA) with a matrix like normal human serum (NHS). Described herein are case studies of biomarker analyses using multiplex LBA which highlight the challenges associated with such adjustments when calculating percent analytical recovery (%AR). The LBA test methods were the Meso Scale Discovery V-PLEX® proinflammatory and cytokine panels with NHS as test matrix. The NHS matrix blank exhibited varied endogenous content of the 20 individual cytokines before spiking, ranging from undetectable to readily quantifiable. Addition and subtraction methods for adjusting endogenous cytokine levels in %AR calculations are both used in the bioanalytical field. The two methods were compared in %AR calculations following spiking and analysis of VS for cytokines having detectable endogenous levels in NHS. Calculations for %AR obtained by subtracting quantifiable endogenous biomarker concentrations from the respective total analytical VS values yielded reproducible and credible conclusions. The addition method, in contrast, yielded %AR conclusions that were frequently unreliable and discordant with values obtained with the subtraction adjustment method. It is shown that subtraction of assay signal attributable to matrix is a feasible alternative when endogenous biomarkers levels are below the limit of quantitation, but above the limit of detection. These analyses confirm that the subtraction method is preferable over that using addition to adjust for detectable endogenous biomarker levels when calculating %AR for biomarker LBA.
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Bioensayo/métodos , Biomarcadores/análisis , Citocinas/análisis , Biomarcadores/sangre , Citocinas/sangre , Humanos , Ligandos , Límite de Detección , Reproducibilidad de los Resultados , Técnica de Sustracción , Estudios de Validación como AsuntoRESUMEN
The topic of incurred sample stability (ISS) has generated considerable discussion within the bioanalytical community in recent years. The subject was an integral part of the seventh annual Workshop on Recent Issues in Bioanalysis (WRIB) held in Long Beach, CA, USA, in April 2013, and at the Global CRO Council for Bioanalysis (GCC) meeting preceding it. Discussion at both events focused on the use of incurred samples for ISS purposes in light of results from a recent GCC survey completed by member companies. This paper reports the consensus resulting from these discussions and serves as a useful reference for depicting ISS issues and concerns, summarizing the GCC survey results and providing helpful recommendations on ISS in the context of bioanalytical method development and application.
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Pruebas de Química Clínica , Recolección de Datos , Reproducibilidad de los ResultadosRESUMEN
A bioassay was developed to assess P-glycoprotein (P-gp) function of peripheral blood natural killer (NK) cells and AML blasts during zosuquidar infusion. Cells were incubated with the fluorescent dye DiOC(2)(3) in the presence and absence of zosuquidar, and dye accumulation measured by flow cytometry. The assay performance was assessed using NK cells and the P-gp-positive K562/R7 cell line, and then utilized to determine the function of P-gp and its inhibition by zosuquidar in AML blasts and NK cells from patients enrolled in a Phase I trial. The assay of zosuquidar-inhibitable accumulation of DiOC(2) is robust and reproducible.
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Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/antagonistas & inhibidores , Dibenzocicloheptenos/uso terapéutico , Células Asesinas Naturales/inmunología , Leucemia Mieloide Aguda/tratamiento farmacológico , Quinolinas/uso terapéutico , Crisis Blástica , Dibenzocicloheptenos/administración & dosificación , Dibenzocicloheptenos/farmacología , Resistencia a Antineoplásicos , Citometría de Flujo , Colorantes Fluorescentes , Humanos , Leucemia Mieloide Aguda/patología , Quinolinas/administración & dosificación , Quinolinas/farmacologíaRESUMEN
Zosuquidar is a potent and specific inhibitor of P-glycoprotein (P-gp). In preliminary experiments, blockade of P-gp for at least 12 h was required to reverse daunorubicin resistance. Because of the short half-life of zosuquidar, we performed a phase I trial of this drug as a 72-h infusion (CIV) in 16 patients during leukemic induction with daunorubicin and cytarabine. Study goals were to establish safety and determine the dose required for P-gp inhibition in NK cells and AML blasts. > 90% P-gp inhibition was achieved within 2h at a plasma threshold of 132 ng/ml zosuquidar. The recommended phase II dose of zosuquidar is 700 mg/day.
Asunto(s)
Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/antagonistas & inhibidores , Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Resistencia a Múltiples Medicamentos , Resistencia a Antineoplásicos , Leucemia Mieloide Aguda/tratamiento farmacológico , Anciano , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Citarabina/administración & dosificación , Citarabina/efectos adversos , Daunorrubicina/administración & dosificación , Daunorrubicina/efectos adversos , Dibenzocicloheptenos/administración & dosificación , Dibenzocicloheptenos/efectos adversos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Quinolinas/administración & dosificación , Quinolinas/efectos adversos , Factores de TiempoRESUMEN
BACKGROUND: Methotrexate (MTX) may produce antiarthritic effects through polyglutamation to methotrexate polyglutamates (MTXPGs), a process that covalently attaches sequential gamma-linked glutamic residues to MTX. We sought to develop an innovative HPLC method for the quantification of these metabolites in erythrocytes. METHODS: Two alternative approaches were developed. In the first approach, MTXPGs from 50 micro L of packed erythrocytes were converted to MTX in the presence of plasma gamma-glutamyl hydrolase and mercaptoethanol at 37 degrees C. In the second approach, MTXPG species (up to the hepta order of glutamation) from 100 micro L packed erythrocytes were directly quantified in a single run. In both methods, the MTXPGs were extracted from the biological matrix by a simple perchloric acid deproteinization step with direct injection of the extract into the HPLC. The chromatography used a C(18) reversed-phase column, an ammonium acetate/acetonitrile buffer, and postcolumn photo-oxidation of MTXPGs to fluorescent analytes. RESULTS: Intra- and interday imprecision (CVs) were <10% at low and high concentrations of analytes for both methods. The limit of quantification was 5 nmol/L. In 70 patients with rheumatoid arthritis receiving weekly low-dose MTX, the mean (SD) total MTXPG concentration measured after conversion of MTXPGs to MTX was similar to the total MTXPG concentration calculated from the sum of individual MTXPG species [117 (56) vs 120 (59) nmol/L; r = 0.97; slope = 1.0]. The triglutamate predominated over all other MTXPG species (36% of total), the pentaglutamate was the highest order of glutamation detected, and a stability study revealed no change in the polyglutamation pattern in erythrocytes 48 h after phlebotomy when the specimen was stored at 2-8 degrees C. CONCLUSION: The proposed method for quantification of erythrocyte MTXPGs is rapid, sensitive, and accurate and can be applied to the routine monitoring of MTX therapy.
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Antirreumáticos/sangre , Artritis Reumatoide/sangre , Eritrocitos/metabolismo , Metotrexato/análogos & derivados , Metotrexato/sangre , Ácido Poliglutámico/análogos & derivados , Ácido Poliglutámico/sangre , Antirreumáticos/administración & dosificación , Antirreumáticos/uso terapéutico , Artritis Reumatoide/tratamiento farmacológico , Calibración , Cromatografía Líquida de Alta Presión , Humanos , Metotrexato/administración & dosificación , Metotrexato/uso terapéutico , Monitoreo Fisiológico , Ácido Poliglutámico/administración & dosificación , Ácido Poliglutámico/uso terapéutico , Reproducibilidad de los Resultados , Sensibilidad y EspecificidadRESUMEN
Interactions between docosanol (n-docosanol, behenyl alcohol) and nucleoside or pyrophosphate analogs were investigated in vitro. The anti-HSV activity of acyclovir (ACV) was synergistically enhanced by treatment of cells with docosanol as judged by inhibition of progeny virus production and plaque formation. This drug interaction between ACV and docosanol was observed with laboratory strains of herpes simplex virus types 1 and 2 (HSV-1 and HSV-2), oral and genital clinical isolates of HSV, cytomegalovirus (CMV), and varicella zoster virus (VZV). Near optimal concentrations of docosanol plus ACV inhibited HSV replication >99% more than either drug alone, including emergence of ACV-resistant variants. The response was observed with African Green Monkey kidney cells, normal human foreskin cells, and normal human lung cells. Treatment of cells with docosanol also synergistically intensified the inhibition of HSV production by all tested nucleoside analogs, including trifluorothymidine (TFT), adenine arabinoside (Ara-A), and ribavirin. An additive anti-HSV effect was observed with docosanol and phosphonoformate (PFA). No evidence was found for either synergistic inhibition of cellular DNA synthesis or induction of overt cellular toxicity when docosanol was combined with ACV, TFT, Ara-A, ribavirin, PFA, 8-azaguanine, or 5-fluorouracil. The ability of docosanol treatment to increase the antiviral activities of nucleoside analog antiviral drugs, coupled with a lack of toxic interactions, translates to substantial improvements in drug selectivity ratios.