Oxxon Announces the Promotion of Dr. Mark Payton to Vice President of Corporate Development.

BOSTON -- Oxxon Therapeutics, Inc. (Oxxon) announced today that Dr. Mark Payton has been promoted to vice president of corporate development at the Company. The promotion of Dr. Payton is part of the Company's increased effort to develop and strengthen its partnering and commercialization team. Oxxon is a biotechnology company developing immunotherapeutics for cancer and chronic infectious diseases.

"Mark has made significant contributions to the Company since joining us in 2001 as business development manager," said Dr. Deirdre Gillespie, president and chief executive officer of Oxxon. "He will continue to be a key part of our growth as we advance our pipeline and focus increasingly on partnering agreements, such as our recent in-licensing agreement with Xenova that Mark helped broker."

Since 2001, Dr. Payton has been managing the business development activities for Oxxon. During this period he has been integral in the implementation of corporate infrastructure elements for the Company, intellectual property management, and the licensing and collaborations efforts. Most recently he has been engaged in the in-licensing of the DISC-HSV and DISC-GM-CSF vector technologies from Xenova Group plc. Prior to joining Oxxon, Dr. Payton served as project manager for Isis Innovation Ltd. During his tenure with Isis, he oversaw 15 license agreements with companies in the United States and Europe, as well as directed over 30 patent applications. Dr. Payton was also a senior Wellcome Trust post-doctoral research assistant at the University of Oxford in the Department of Pharmacology, where he managed research leading to a patent application on drug resistance and novel anti-mycobacterial drug discovery.

Dr. Payton received his Ph.D. in Molecular Immunology from King's College London, University of London. He has an MBA from the Warwick Business School and was chosen as a Sainsbury Management Fellow in the Life Sciences.

Currently, Oxxon's pipeline has two programs in Phase II clinical trials, one for melanoma and the other focused on hepatitis B. As well, the Company's late-stage pre-clinical program for HIV is expected to enter the clinic in the later half of 2005. Oxxon anticipates data from ongoing clinical trials by year-end.

About Oxxon Therapeutics, Inc.

Oxxon Therapeutics, Inc. (Oxxon) is advancing the next generation of innovative immunotherapies to treat patients with chronic infectious diseases and cancer. To date, the company has built a pipeline through its proprietary PrimeBoost platform, an approach that allows the rapid development of products to selectively stimulate and enhance a potent cellular immune response. The Company has five development programs in hepatitis, melanoma and HIV, two of which are in Phase II clinical trials. In addition, the Company is leveraging its enabling platform through partnerships with companies and academic collaborations.

For more information, please visit www.oxti.com