Orphan drug products are drugs, vaccines or in vivo diagnostic agents which physicians use to treat, prevent or diagnose rare diseases. Usually the drugs are not commercially viable. Pharmaceutical companies often do not develop and market such products because the financial return is small compared with the costs of development and marketing. When a drug has no sponsor for this reason, it is known as an ‘orphan drug.’ The Australian Program encourages sponsors to market orphan drugs in Australia by reducing costs through waiving fees and by providing exclusive approval. The TGA will waive fees for the application for orphan drug designation, the application for registration and for the initial evaluation of data.