A paradigm shift in tumour response evaluation of targeted therapy

Abstract

To describe the difficulty in assessing the biological activity of a novel agent in phase II trials. Two major fields of research provide interesting new potential endpoints: endpoints based on new imaging techniques (e.g. PET or spectral imaging that explore tumour metabolism, dynamic contrast enhanced (DCE) ultrasonography or DCE-MRI that explore tumour vascularization and tumour growth inhibition) and endpoints integrating assessment of tumour burden across time, such as the growth modulation index. Most of the recently described techniques appear attractive, but require formal validation.