title: Determination of Cellular Processing Rates for a Trastuzumab-Maytansinoid Antibody-Drug Conjugate (ADC) Highlights Key Parameters for ADC Design.
abstract: Antibody-drug conjugates (ADCs) are a promising class of cancer therapeutics that combine the specificity of antibodies with the cytotoxic effects of payload drugs. A quantitative understanding of how ADCs are processed intracellularly can illustrate which processing steps most influence payload delivery, thus aiding the design of more effective ADCs. In this work, we develop a kinetic model for ADC cellular processing as well as generalizable methods based on flow cytometry and fluorescence imaging to parameterize this model. A number of key processing steps are included in the model: ADC binding to its target antigen, internalization via receptor-mediated endocytosis, proteolytic degradation of the ADC, efflux of the payload out of the cell, and payload binding to its intracellular target. The model was developed with a trastuzumab-maytansinoid ADC (TM-ADC) similar to trastuzumab-emtansine (T-DM1), which is used in the clinical treatment of HER2+ breast cancer. In three high-HER2-expressing cell lines (BT-474, NCI-N87, and SK-BR-3), we report for TM-ADC half-lives for internalization of 6-14 h, degradation of 18-25 h, and efflux rate of 44-73 h. Sensitivity analysis indicates that the internalization rate and efflux rate are key parameters for determining how much payload is delivered to a cell with TM-ADC. In addition, this model describing the cellular processing of ADCs can be incorporated into larger pharmacokinetics/pharmacodynamics models, as demonstrated in the associated companion paper.
authors.affiliation: Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.|David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.
authors.forename: Katie F
authors.initials: KF
authors.lastname: Maass
authors.affiliation: Oncology Medicinal Chemistry, Worldwide Medicinal Chemistry, Pfizer, Groton, Connecticut, USA.
authors.forename: Chethana
authors.initials: C
authors.lastname: Kulkarni
authors.affiliation: Translational Research Group, Department of Pharmacokinetics Dynamics and Metabolism, Pfizer, Groton, Connecticut, USA.
authors.forename: Alison M
authors.initials: AM
authors.lastname: Betts
authors.affiliation: Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA. wittrup@mit.edu.|David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA. wittrup@mit.edu.|Department of Biological Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave. 76-261D, Cambridge, Massachusetts, 02139, USA. wittrup@mit.edu.
authors.forename: K Dane
authors.initials: KD
authors.lastname: Wittrup
mesh_terms: D061067:Antibodies, Monoclonal, Humanized / Q000737:chemistry / Q000378:metabolism*; D000970:Antineoplastic Agents / Q000737:chemistry / Q000378:metabolism*; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000378:metabolism*; D015195:Drug Design; D006801:Humans; D008453:Maytansine / Q000737:chemistry / Q000378:metabolism*; D000068878:Trastuzumab / Q000737:chemistry / Q000378:metabolism*
chemical_list: D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents; D008453:Maytansine; D000068878:Trastuzumab
keywords: T-DM1; antibody-drug conjugate; cellular trafficking; pharmacokinetics/pharmacodynamics; trastuzumab emtansine