RESUMO
A phage-derived human monoclonal antibody against VEGF-C was developed as a potential anti-tumor therapeutic and exhibited fast clearance in preclinical species, with notably faster clearance in serum than in plasma. The purpose of this work was to understand the factors contributing to its fast clearance. In vitro incubations in animal and human blood, plasma, and serum were conducted with radiolabeled anti-VEGF-C to determine potential protein and cell-based interactions with the antibody as well as any matrix-dependent recovery dependent upon the matrix. A tissue distribution study was conducted in mice with and without heparin infusion in order to identify a tissue sink and determine whether heparin could affect antibody recovery from serum and/or plasma. Incubation of radiolabeled anti-VEGF-C in human and animal blood, plasma, or serum revealed that the antibody formed a complex with an endogenous protein, likely VEGF-C. This complex was trapped within the blood clot during serum preparation from blood, but not within the blood cell pellet during plasma preparation. Low level heparin infusion in mice slowed down clot formation during serum preparation and allowed for better recovery of the radiolabeled antibody in serum. No tissue sink was found in mice. Thus, during this characterization, we determined that the blood sampling matrix greatly impacted the amount of antibody recovered in the samples, therefore, altering its derived pharmacokinetic parameters. Target biology should be considered when selecting appropriate sampling matrices for PK analysis.
Assuntos
Anticorpos Monoclonais/farmacocinética , Fator C de Crescimento do Endotélio Vascular/antagonistas & inibidores , Animais , Anticorpos Monoclonais/sangue , Artefatos , Coagulação Sanguínea , Feminino , Humanos , Macaca fascicularis , Camundongos Nus , Ratos Sprague-Dawley , Distribuição Tecidual , Fator C de Crescimento do Endotélio Vascular/imunologiaRESUMO
PURPOSE: We characterized the pharmacokinetics of onartuzumab (MetMAb) in animals and determined a concentration-effect relationship in tumor-bearing mice to enable estimation of clinical pharmacokinetics and target doses. EXPERIMENTAL DESIGN: A tumor growth inhibition model was used to estimate tumoristatic concentrations (TSC) in mice. Human pharmacokinetic parameters were projected from pharmacokinetics in cynomolgus monkeys by the species-invariant time method. Monte Carlo simulations predicted the percentage of patients achieving steady-state trough serum concentrations (Ctrough ss) ≥TSC for every 3-week (Q3W) dosing. RESULTS: Onartuzumab clearance (CL) in the linear dose range was 21.1 and 12.2 mL/d/kg in mice and cynomolgus monkeys with elimination half-life at 6.10 and 3.37 days, respectively. The estimated TSC in KP4 pancreatic xenograft tumor-bearing mice was 15 µg/mL. Projected CL for humans in the linear dose range was 5.74 to 9.36 mL/d/kg with scaling exponents of CL at 0.75 to 0.9. Monte Carlo simulations projected a Q3W dose of 10 to 30 mg/kg to achieve Ctrough ss of 15 µg/mL in 95% or more of patients. CONCLUSIONS: Onartuzumab pharmacokinetics differed from typical bivalent glycosylated monoclonal antibodies with approximately 2-times faster CL in the linear dose range. Despite this higher CL, xenograft efficacy data supported dose flexibility with Q1W to Q3W dose regimens in the clinical setting with a TSC of 15 µg/mL as the Ctrough ss target. The projected human efficacious dose of 10 to 30 mg/kg Q3W should achieve the target TSC of 15 µg/mL. These data show effective pharmacokinetic/pharmacodynamic modeling to project doses to be tested in the clinic.
Assuntos
Anticorpos Monoclonais/administração & dosagem , Anticorpos Monoclonais/farmacocinética , Carcinoma Ductal Pancreático/tratamento farmacológico , Neoplasias Pancreáticas/tratamento farmacológico , Animais , Western Blotting , Carcinoma Ductal Pancreático/metabolismo , Simulação por Computador , Relação Dose-Resposta a Droga , Feminino , Meia-Vida , Humanos , Técnicas Imunoenzimáticas , Imunoprecipitação , Macaca fascicularis , Camundongos , Camundongos Nus , Método de Monte Carlo , Neoplasias Pancreáticas/metabolismo , Valor Preditivo dos Testes , Distribuição Tecidual , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
PURPOSE: PRO95780, a human monoclonal antibody (mAb) against death receptor 5 (DR5/TRAIL-R2/TNFRSF10B), was developed for the treatment for cancer. Our objective was to characterize pharmacokinetics (PK) in mice, rats, and cynomolgus monkeys and concentration-effect relationships of PRO95780 in xenograft mouse models of human cancers; this would guide the selection of dose and regimen for clinical trials. METHODS: The PK profiles were determined in mice, rats, and cynomolgus monkeys. Three xenograft models with a wide range of in vitro sensitivities to PRO95780 were selected for efficacy studies. Tumoristatic serum concentrations (TSCs) were determined using PK/pharmacodynamic (PD) modeling with tumor growth as a PD endpoint. A species-invariant time PK scaling method was employed to estimate disposition in humans using PK data in cynomolgus monkeys. Furthermore, the predicted human PK parameters were used to estimate dose and regimen to achieve TSC observed in mice at the steady-state trough concentrations (C trough ss) in the clinic. RESULTS: Linear PK was observed across species. A serum concentration of 22 µg/mL was identified to be the target TSC in mice. A dose of 10 mg/kg administered once every 2 weeks (Q2W) was predicted to achieve a TSC at C trough ss in 95 % of patients. CONCLUSIONS: PRO95780 has linear PK in mice, rats, and monkeys. Estimated TSCs varied among different xenograft models. A projected target dose in humans is achievable for Q2W administration within the dose range used for other commercial mAbs.
Assuntos
Anticorpos Monoclonais/administração & dosagem , Anticorpos Monoclonais/farmacocinética , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/agonistas , Animais , Anticorpos Monoclonais Humanizados , Área Sob a Curva , Linhagem Celular Tumoral , Relação Dose-Resposta a Droga , Ensaio de Imunoadsorção Enzimática , Feminino , Meia-Vida , Humanos , Injeções Intravenosas , Macaca fascicularis , Camundongos , Camundongos Nus , Modelos Estatísticos , Transplante de Neoplasias , Ratos , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Off-target binding can significantly affect the pharmacokinetics (PK), tissue distribution, efficacy and toxicity of a therapeutic antibody. Herein we describe the development of a humanized anti- fibroblast growth factor receptor 4 (FGFR4) antibody as a potential therapeutic for hepatocellular carcinoma (HCC). A chimeric anti FGFR4 monoclonal antibody (chLD1) was previously shown to block ligand binding and to inhibit FGFR4 mediated signaling as well as tumor growth in vivo. A humanized version of chLD1, hLD1.vB, had similar binding affinity and in vitro blocking activity, but it exhibited rapid clearance, poor target tissue biodistribution and limited efficacy when compared to chLD1 in a HUH7 human HCC xenograft mouse model. These problems were traced to instability of the molecule in rodent serum. Size exclusion high performance liquid chromatography, immunoprecipitation and mass spectral sequencing identified a specific interaction between hLD1.vB and mouse complement component 3 (C3). A PK study in C3 knock-out mice further confirmed this specific interaction. Subsequently, an affinity-matured variant derived from hLD1.vB (hLD1.v22), specifically selected for its lack of binding to mouse C3 was demonstrated to have a PK profile and in vivo efficacy similar to that of chLD1 in mice. Although reports of non-specific off-target binding have been observed for other antibodies, this represents the first report identifying a specific off-target interaction that affected disposition and biological activity. Screens developed to identify general non-specific interactions are likely to miss the rare and highly specific cross-reactivity identified in this study, thus highlighting the importance of animal models as a proxy for avoiding unexpected clinical outcomes.
Assuntos
Anticorpos Monoclonais Humanizados/imunologia , Anticorpos Monoclonais/imunologia , Afinidade de Anticorpos , Antineoplásicos/imunologia , Complemento C3/metabolismo , Receptor Tipo 4 de Fator de Crescimento de Fibroblastos/imunologia , Sequência de Aminoácidos , Animais , Anticorpos Monoclonais/química , Anticorpos Monoclonais/metabolismo , Anticorpos Monoclonais/farmacocinética , Anticorpos Monoclonais Humanizados/química , Anticorpos Monoclonais Humanizados/metabolismo , Anticorpos Monoclonais Humanizados/farmacocinética , Antineoplásicos/química , Antineoplásicos/farmacocinética , Antineoplásicos/uso terapêutico , Carcinoma Hepatocelular/terapia , Linhagem Celular Tumoral , Complemento C3/genética , Humanos , Neoplasias Hepáticas/terapia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Nus , Dados de Sequência MolecularRESUMO
Bevacizumab [Avastin; anti-vascular endothelial growth factor (VEGF) antibody] is an antiangiogenic IgG approved for treating patients with certain types of colon, breast, and lung cancer. In these indications, bevacizumab is administered every 2 to 3 weeks, prompting us to study ways to reduce the frequency of administration. Increasing affinity to neonatal Fc receptor (FcRn) may extend the pharmacokinetic half-life of an antibody, but the quantitative effect of FcRn affinity on clearance has not been clearly elucidated. To gain further insight into this relationship, we engineered a series of anti-VEGF antibody variants with minimal amino acid substitutions and showed a range of half-life improvements in primates. These results suggest that, if proven clinically safe and effective, a modified version of bevacizumab could potentially provide clinical benefit to patients on long-term anti-VEGF therapy through less-frequent dosing and improved compliance with drug therapy. Moreover, despite having half-life similar to that of wild-type in mice due to the species-specific FcRn binding effects, the variant T307Q/N434A exhibited superior in vivo potency in slowing the growth of certain human tumor lines in mouse xenograft models. These results further suggest that FcRn variants may achieve increased potency through unidentified mechanisms in addition to increased systemic exposure.