Cambridge, MA, March 31, 2003 - Transatlantic Investment Management, Inc. today announced that Therion Biologics Corporation has leased 8,400 square feet of office space at the American Twine Office Park. The building is an historic, renovated brick and beam building located in East Cambridge, Massachusetts. Therion will be using the space for their executive offices and for clinical, regulatory, and accounting functions.

�The American Twine building is located in the heart of the biotech center of East Cambridge. This is perfect for our business and less than one block from our laboratory and manufacturing facilities,� said George Eldridge, Senior Vice President and Chief Financial Officer of Therion. �The owners and managers of the building were very responsive to our needs. We were quickly able to align our business interests with theirs, get a lease negotiated and have our build out finished.�

With the Cambridge office market at historic lows, the Therion lease is an example of an important trend occurring in this market. Meredith and Grew, Inc. put the vacancy rate in Cambridge at 23.2% at the end of the fourth quarter of 2002, with 400,000 square feet more space vacant at the end of the year than at the beginning. With little to no growth in Cambridge�s traditional technology tenants, biotechnology related office use represents a key source of future demand. Transatlantic Management has been able to capitalize on this trend.

�We believe that office space usage in Cambridge will benefit from the increased biotechnology tenant base in the city. As these companies grow, they will have increasing needs for office users to support their research and laboratory needs,� said Anthony Goschalk, president of Transatlantic Investment Management. �Given the high vacancy rates for office buildings in East Cambridge, we are gratified that we have been able to have the American Twine building over 90% occupied.�

In addition to the Therion lease, Transatlantic Investment Management has leased over 11,000 square feet of office space at the American Twine Office Park for biotechnology related businesses in the last 12 months. This brings the total biotechnology related office use in the building to over 21,000 square feet.

About Therion Biologics Corporation
Therion Biologics Corporation develops therapeutic vaccines for cancer and preventive vaccines for AIDS. The company has three lead programs involving multiple clinical trials: PROSTVAC^®-VF/TRICOM� for prostate cancer; CEA/MUC-1-VF/TRICOM for pancreatic cancer; and VF/TRICOM for melanoma. Therion is also applying its technology platform to develop vaccines to treat breast cancer and other solid tumors. The company�s strategic partners include Aventis Pasteur, which is developing a clinical candidate for colon cancer, ALVAC-CEA/B7.1, the National Cancer Institute and a global network of leading clinical institutions. Therion is headquartered in Cambridge, Massachusetts.

About Transatlantic Investment Management, Inc.
Transatlantic Investment Management is a real estate investment and management company located in Cambridge, Massachusetts. It provides asset management services for selected high net-worth individuals and investment groups, and premium quality property management services for small and medium sized office portfolios. The principals of Transatlantic Investment Management have a broad base of experience in both real estate and general business management. The company�s focus is to offer the care and attention of a family business coupled with the sophistication, professionalism and use of modern technology demanded by its tenants, investment partners and service clients.