In-depth biophysical analysis of interactions between therapeutic antibodies and the extracellular domain of the epidermal growth factor receptor.

Targeting of the epidermal growth factor receptor (EGFR) with monoclonal antibodies has become an established antitumor strategy in clinical use or in late stages of drug development. The mAbs effector mechanisms have been widely analyzed based on in vivo or cell studies. Hereby we intend to complement these functional studies by investigating the mAb-EGFR interactions on a molecular level. Surface plasmon resonance, isothermal titration calorimetry, and static light scattering were employed to characterize the interactions of matuzumab, cetuximab, and panitumumab with the extracellular soluble form ecEGFR. The kinetic and thermodynamic determinants dissected the differences in mAbs binding mechanism toward ecEGFR. The quantitative stoichiometric data clearly demonstrated the bivalent binding of the mAbs to two ecEGFR molecules. Our results complement earlier studies on simultaneous binding of cetuximab and matuzumab. The antibodies retain their bivalent binding mode achieving a 1:2:1 complex formation. Interestingly the binding parameters remain nearly constant for the individual antibodies in this ternary assembly. In contrast the binding of panitumumab is almost exclusive either by directly blocking the accessibility for the second antibody or by negative allosteric modulation. Overall we provide a comprehensive biophysical dataset on binding parameters, the complex assembly, and relative epitope accessibility for therapeutic anti-EGFR antibodies.

Prospective Assessment of an innovative test for prostate cancer screening using the VITA process model framework.

Healthcare innovations are crucial for enhancing patient treatment and a high-quality healthcare system. However, bringing new technologies, methods and procedures into the healthcare market is challenging. Enormous amounts of financial, personnel and organizational resources are required with no upfront certainty for the medical and economic benefit. A new and innovative approach uses interdisciplinary medical, technical and economic expertise to forecast effects of healthcare innovations already at the early research and concept phase of an idea and before major investments are made. A process model framework was developed to operationalize this structured assessment of healthcare innovations. The Visionary Iterative Tailored Approach (VITA) is based on conceptual modeling, simulation and health economics evaluation. Its application for the prospective assessment of an innovative prostate cancer screening is presented.