By Ben Hargreaves

Testing drug compounds on a chip designed to mimic human organs sounds closer to science fiction than reality, yet the technology already exists and is already being put to use. Ben Hargreaves discovers how the technology could provide more accurate safety predictions and even discover new treatments.

The limits of animal models in drug discovery are well known. If you are reading this then you are likely not a mouse, and as a result, will react to drug compounds differently. In testing new treatments, what is promising in animal models may not transfer particularly well to humans, which helps to explain why there is a 90% failure rate during clinical development. The low rate of success is one of the contributors to the high cost and the slow R&D process that takes promising compounds through early testing and into the clinic. Moreover, there is the question of the ethics of using animals, numbering in the millions each year, in clinical trials, which sees most euthanized at the end of the process.

The challenge that the pharma industry faces is the lack of better alternatives to animal models. There are existing alternatives, with one being human cell culture systems, which provide an environment that is closer to that which will eventually receive treatment but do not contain the complexity of a complete organism. An organoid system approach takes self-organising clusters of cells that grow in three dimensions, closely resembling real tissue and organs. Despite the potential, there are limiting factors such as the need to provide optimal culturing conditions for different types of organoid, with each potentially containing a range of cells types. An alternative to these systems is one that is growing in popularity and commercial application, a technology referred to as ‘organ-on-a-chip’.