Steve Parkinson
President and CEO
TranXenoGen, Inc.
(508) 842 5036
Wendy Wolfson
Media Relations
(617) 628 9310
(617) 306 9523 mobile
Charles Linn Haslam
President and CEO
U.S. Transgenics, Inc.
(202) 333 7226
TranXenoGen and U.S. Transgenics Announce Joint Venture to Produce HSA

And a Collaboration for Additional Proteins

Shrewsbury, MA, January 28, 2000 – TranXenoGen, Inc. and U.S. Transgenics, Inc. announced today that they had signed letters of intent to form an equally owned joint venture to develop recombinant Human Serum Albumin (HSA) and a collaboration to produce other proteins in the albumin fraction of transgenic chicken eggs. The agreements will employ TranXenoGen’s proprietary transgenic chicken technology. Financial terms were not disclosed.

The initial HSA product development will take place at TranXenoGen’s Shrewsbury, MA, laboratories and the chickens will be housed at a new TranXenoGen facility which is in the planning stages. US Trangenics will provide protein chemistry technology and access to significant product markets. The companies expect to be in commercial production by 2003.

TranXenoGen President and Chief Executive Officer Steve Parkinson and U.S. Transgenics President and Co-founder Charles Linn Haslam estimated that the worldwide

market for HSA to be in excess of 440 tons of protein per year with a present market value of $1.3 billion. TranXenoGen anticipates that it will be able to produce 10 to 15 tons of HSA using 100,000 chickens, a flock size fairly typical of commercial poultry farming operations.

Under the collaboration agreement, TranXenoGen will develop transgenic chickens expressing initially two plasma proteins in the albumin fraction of their eggs. U.S. Transgenics has the option to have TranXenoGen develop four additional protein products which may include plasma proteins for unique indications.

Based in Washington, DC, U.S. Transgenics is a development stage biotechnology company engaged in developing plasma and novel platform proteins. The Company was founded in 1999 to commercialize certain plasma products and to offer a broad range of transgenic expertise and services to the pharmaceutical and scientific communities.

Headquartered in Shrewsbury, MA, TranXenoGen is a biotechnology company that is developing generic biologicals through transgenic animal production and cloning. The Company is primarily applying its proprietary second-generation transgenic technology to create transgenic chickens expressing proteins in the albumin of their eggs. The Company is also offering its transgenic and cloning technology for the efficient manufacture of novel products and to create genetically modified animals as donors of organs and cells for xenotranplantation to human recipients.

# # #