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1.
Clin Res Hepatol Gastroenterol ; 48(7): 102380, 2024 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-38788975

RESUMO

BACKGROUND: Visceral fat produces angiogenic factors such as vascular endothelial growth factor that promote tumoral growth. However, its influence on outcome for patients with advanced cancer treated with anti-angiogenic agents is controversial. AIMS: The aim of this study was to determine whether visceral fat volume, visceral fat area and body mass index are associated with outcome in patients receiving first-line bevacizumab-based treatment for metastatic colorectal cancer. METHODS: This multicenter prospective study included 103 patients with metastatic colorectal cancer who received first-line bevacizumab-based chemotherapy. Computed tomography was used to measure visceral fat volume and visceral fat area. Endpoints were tumoral response at 2 months, progression free survival and overall survival. RESULTS: Visceral fat volume and visceral fat area, but not body mass index, were significantly associated with better outcome. Using sex-specific median values progression free survival was significantly longer in patients with high visceral fat volume (13.2 versus 9.4 months; p = 0.0043). In the same way, high visceral fat volume and visceral fat area were associated with a significantly better overall survival: 31.3 versus 20.5 months (p = 0.0072) and 29.3 versus 20.5 months (p = 0.0078), respectively. By multivariate analysis, visceral fat volume was associated with longer progression free survival and overall survival. CONCLUSION: This study demonstrates that a high visceral fat volume is associated with better outcome in patients receiving first-line bevacizumab-based chemotherapy for metastatic colorectal cancer.

2.
Br J Clin Pharmacol ; 90(4): 976-986, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38072829

RESUMO

AIMS: The exposure-response relationship of bevacizumab may be confounded by various factors, including baseline characteristics, time-dependent target engagement and recursive relationships between exposure and response, requiring effective mitigation. This study aimed to investigate the exposure-response relationships of bevacizumab in metastatic colorectal cancer (mCRC) patients while mitigating potential biases. METHODS: Bevacizumab pharmacokinetics was described using target-mediated drug disposition modelling. Relationships between target kinetics, progression-free (PFS) and overall (OS) survivals were assessed using joint pharmacokinetic and parametric hazard function models. Both prognostic-driven and response-driven potential biases were mitigated. These models evaluated the impact of increased antigen target levels, clearance and intensified dosing regimen on survival. RESULTS: Estimated target-mediated pharmacokinetic parameters in 130 assessed patients were baseline target levels (R0 = 8.4 nM), steady-state dissociation constant (KSS = 10 nM) and antibody-target complexes elimination constant (kint = 0.52 day-1). The distribution of R0 was significantly associated with increased baseline concentrations of carcinoembryonic antigen, circulating vascular endothelial growth factor and the presence of extrahepatic metastases. Unbound target levels (R) significantly influenced both progression and death hazard functions. Increasing baseline target levels and/or clearance values led to decreased bevacizumab unbound concentrations, increased R levels and shortened PFS and OS, while increasing bevacizumab dose led to decreased R and longer survival. CONCLUSION: This study is the first to demonstrate the relationship between bevacizumab concentrations, target involvement and clinical efficacy by effectively mitigating potential sources of bias. Most of the target amount may be tumoural in mCRC. Future studies should provide a more in-depth description of this relationship.


Assuntos
Neoplasias Colorretais , Neoplasias Retais , Humanos , Bevacizumab , Fator A de Crescimento do Endotélio Vascular , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/patologia , Intervalo Livre de Doença , Resultado do Tratamento , Protocolos de Quimioterapia Combinada Antineoplásica , Fluoruracila
3.
Clin Pharmacokinet ; 62(9): 1263-1274, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37442917

RESUMO

BACKGROUND AND OBJECTIVE: Cetuximab, an anti-epidermal growth factor receptor (EGFR) monoclonal immunoglobulin (Ig)G1 antibody, has been approved for the treatment of metastatic colorectal cancer (mCRC). The influence of target-antigen on cetuximab pharmacokinetics has never been investigated using target-mediated drug disposition (TMDD) modelling. This study aimed to investigate the relationship between cetuximab concentrations, target kinetics and progression-free survival (PFS). METHODS: In this ancillary study (NCT00559741), 91 patients with mCRC treated with cetuximab were assessed. Influence of target levels on cetuximab pharmacokinetics was described using TMDD modelling. The relationship between cetuximab concentrations, target kinetics and time-to-progression (TTP) was described using a joint pharmacokinetic-TTP model, where unbound target levels were assumed to influence hazard of progression by an Emax model. Mitigation strategies of concentration-response relationship, i.e., time-varying endogenous clearance and mutual influences of clearance and time-to-progression were investigated. RESULTS: Cetuximab concentration-time data were satisfactorily described using the TMDD model with quasi-steady-state approximation and time-varying endogenous clearance. Estimated target parameters were baseline target levels (R0 = 43 nM), and complex elimination rate constant (kint = 0.95 day-1). Estimated time-varying clearance parameters were time-invariant component of CL (CL0= 0.38 L/day-1), time-variant component of CL (CL1= 0.058 L/day-1) and first-order rate of CL1 decreasing over time (kdes = 0.049 day-1). Part of concentration-TTP was TTP-driven, where clearance and TTP were inversely correlated. In addition, increased target occupancy was associated with increased TTP. CONCLUSION: This is the first study describing the complex relationship between cetuximab target-mediated pharmacokinetics and PFS in mCRC patients using a joint PK-time-to-progression model. Further studies are needed to provide a more in-depth description of this relationship.


Assuntos
Antineoplásicos , Neoplasias Colorretais , Humanos , Cetuximab/uso terapêutico , Cetuximab/farmacocinética , Intervalo Livre de Progressão , Anticorpos Monoclonais Humanizados/uso terapêutico , Anticorpos Monoclonais Humanizados/farmacocinética , Anticorpos Monoclonais/uso terapêutico , Anticorpos Monoclonais/farmacocinética , Antineoplásicos/uso terapêutico , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/patologia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico
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