RESUMO
M701 is a bispecific CD3/EpCAM T-cell engager antibody for the treatment of malignant ascites. We developed a population pharmacokinetic/pharmacodynamic (PK/PD) model to quantitatively describe and predict the antitumor effect of M701 in human colorectal cancer xenograft mice. We developed the M701 PK model based on plasma concentration data after i.v. administration. A tumor growth model for human colorectal cancer xenograft was developed to evaluate the antitumor effect of M701. We additionally simulated the inhibitory effect of M701 on tumor volume under different dose regimens based on a PK/PD model. A two-compartment model was developed to predict the PK in human colorectal cancer xenograft mice. The relationship between the M701 concentration and tumor growth inhibition was characterized by a combined Simeoni tumor growth/transit compartment model. The estimated pharmacodynamic parameters were related to the tumor growth characteristics λ0 (0.212 d-1) and λ1 (0.044 7 cm3·d-1), to the drug potency k2 (0.071 5 mL·ng-1·d-1), and to the kinetics of tumor cell death k1 (2×10-5 d-1). A model visual predictive check showed that both the PK model and the tumor growth model closely fit the observed data. Simulated tumor growth after administration of M701 (0.5 mg·kg-1 every 6 days and 0.25 mg·kg-1 every 3 days) could be effectively inhibited. This population PK/PD model of M701 provides insight into the antitumor effect of M701 and supports the further therapeutic development of M701.