Compassionate use (also referred to as expanded access) is therapeutic use of unauthorized drugs outside of clinical trials. The objective of this review is to discuss practical aspects of the current legal regulations concerning compassionate use that have been introduced in the European Union, the USA (both the Food and Drug Administration regulations and Right-to-try laws), Canada and Australia. We also present main ethical challenges associated with use of unauthorized drugs such as possible difficulties with obtaining informed consent and fair patient selection.
