Recent progress in plantibody technology.
Antibodies are an important class of proteins that can be used for the prevention, treatment and diagnosis of many diseases. Consequently, there is an intense and growing demand for recombinant antibodies, placing immense pressure on current production capacity which is based largely on microbial cultures and mammalian cells. Alternative systems for cost effective antibody production would be very welcome, and plants are now gaining widespread acceptance as green bioreactors with advantages in terms of cost, scalability and safety. Several plant-produced antibodies (plantibodies) are undergoing clinical trials and the first commercial approval could be only a few years away. The performance of the first generation of products has been very encouraging so far. In terms of product authenticity, differences in glycosylation between plantibodies and their mammalian counterparts have been defined, and the scientific evaluation of any possible consequences is underway. Ongoing studies are addressing the remaining biochemical constraints, and aim to further improve product yields, homogeneity and authenticity, particularly where the antibody is intended for injection into human patients. A remaining practical challenge is the implementation of large-scale production and processing under good manufacturing practice conditions that are yet to be endorsed by regulatory bodies. The current regulatory uncertainty and the associated costs represent an entry barrier for the pharmaceutical industry. However, the favourable properties of plants are likely to make the plant systems a useful alternative for small, medium and large scale production throughout the development of new antibody-based pharmaceuticals.