For further information, please contact: TranXenoGen, Inc. Tel: 001 508 842 5036 Steve Parkinson, President and CEO Email: SParkinson@TranXenoGen.com College Hill Associates Tel: 020 7457 2020 Michael Padley/Nicholas Nelson January 31, 2001 TRANXENOGEN ANNOUNCES THE DEVELOPMENT OF GERMLINE TRANSGENIC CHICKENS TranXenoGen, Inc. ("TranXenoGen"), the AIM listed company which plans to establish itself as a leading protein drug manufacturing company using its proprietary transgenic technology, announces that it has achieved an important milestone for the low cost production of therapeutic proteins from chicken eggs. The company has generated germline transgenic chickens that have an additional gene coding for insulin in all their cells. The company believes that this is the first report of a germline transgenic chicken produced using non-viral transfection technology. The second-generation germline birds have been bred from chimeric chickens produced using TranXenoGen’s non–viral transfection technology and proprietary expression vector. A chimeric chicken contains the additional gene or ‘transgene’ in only some of its cells and when bred may pass the gene on to the second generation where all the cells contain the transgene. Commenting on the development, TranXenoGen’s Vice President of Product Development, Paul DiTullio, said: "This is an important milestone for the company. We have succeeded in our initial goal, to use our non-viral transgenic technology to generate one or more transgenic chickens. Our next goal will be to achieve high-level expression of our generic products and antibodies in the egg albumin of our transgenic chickens. Production of additional transgenic birds with new versions of the transgenes will help ensure we achieve the desired expression levels of these proteins, and thus, take the next step in realizing a low-cost method for the manufacture of complex proteins." TranXenoGen’s President and CEO, Steve Parkinson, said: "Insulin is one of four generic biological products that we have in development. We expect insulin to be the first of these products that we launch onto the market, and so the generation of the first germline birds is an important achievement. Once we have chosen the germline transgenic or founder bird, that is, the chicken, which gives the highest yield of insulin, we will move forward to breed the production flock. This technology is particularly suited to the production of complex proteins such as antibodies, which require two genes to be inserted. We expect this to be perhaps the most important application of our technology as shown by our recently announced collaborations with two leading antibody development companies."