Bayer Innovation GmbH Make Milestone on Antibodies from Plants.

Icon Genetics GmbH, a wholly owned subsidiary of Bayer Innovation GmbH, and Bayer BioScience NV, a Belgian subsidiary of Bayer CropScience announce the publication in Proceedings of the National Academy of Sciences of the USA (A. Giritch et al., Proc. Natl. Acad. Sci. USA, pnas. 0606631103, September 2006) of the third of a series of research papers titled "Rapid high-yield expression of full-size IgG antibodies in plants coinfected with noncompeting viral vectors" describing a new-generation expression technology for plants developed by Icon and Bayer researchers.

Since the discovery of this technology 17 years ago, the ability of plants to express full-size human antibodies has not been exploited because of low yields and the length of time necessary to generate just small amounts of research material. Using two different plant viral vectors and transient co-expression technology, our scientists have developed a process that provides a high-yield expression of monoclonal antibodies (mabs) and takes less than two weeks. The method is exemplified by producing the human tumor-specific monoclonal antibody A5 IgG1. With yields as high as 0.5 grams of IgG1 per kilogram of plant material, the proposed process is suitable for the research, industrial scale-up and rapid manufacture of antibodies for health care use. It is also applicable in situations requiring rapid response such as pandemic events.

This new process represents a significant technical advancement that broadens the versatility of our second-generation expression platform technology, magnifection. This transient expression process is used to start gene amplification in all mature leaves of a plant simultaneously, leading to high expression levels. It is indefinitely scalable and can be done on an industrial scale. This eclectic technology combines the advantages of three biological systems: (1) vector efficiency and efficient systemic DNA delivery of Agrobacterium, (2) speed and expression level/yield of a plant RNA virus, and (3) posttranslational capabilities and low production costs of plants. The two other versions of this technology have been described previously by Icon Genetics researchers in Proceedings of the National Academy of Sciences of the USA (Marillonnet et al., Proc. Natl. Acad. Sci. USA, 101, 6852, 2004) and Nature Biotechnology (Marillonnet et al., Nat. Biotechnol, 23, 718, 2005).

"We are taking the lead in moving plant-made biopharmaceuticals closer to commercial reality," says Dr. Wolfgang Plischke, member of the Board of Management of Bayer AG. "The acquisition of Icon Genetics not only brought us a potentially disruptive manufacturing technology but also a highly motivated team of talented scientists. I am glad to see that their work is now being integrated into the broader innovation effort at Bayer."

The Proceedings of the National Academy of Sciences can be accessed at:
http://www.pnas.org.