OXiGENE Announces the Initiation of a Phase I Clinical Trial of OXi4503 in Patients with Advanced Cancer

WALTHAM, Mass. -- December 22, 2004 -- OXiGENE, Inc. (NASDAQ: OXGN, XSSE: OXGN) announced the initiation of a Phase I trial of OXi4503 in advanced cancer patients. OXi4503 has been shown in animals to have potent anti-tumor activity as both a single-agent and in combination therapy. This Phase I trial propels the Company forward into the clinical development of two distinct technology platforms resulting in a total of ten clinical trials in oncology and ophthalmology.

“OXi4503 is the lead compound in a novel class of agents that we have termed ortho-quinone prodrugs (OQPs). This agent is of particular interest in that it exhibits not only the vascular disrupting properties characteristic of our lead vascular targeting agent CA4P, but can also cause direct cytotoxicity to tumor cells,” said Dr. Dai Chaplin, Chief Scientific Officer of OXiGENE. “Since this is the first in a class of this type of agent, the trial has been designed to obtain information not only on safety but also to gain further insight into the mechanism of action of OXi4503.”

The planned study, to be run by Cancer Research UK, will be a dose escalating trial in which the primary endpoints are safety, tolerability and pharmacokinetics. Although ostensibly a Phase I safety study, the protocol design has incorporated advanced testing to monitor patients through extensive blood work, MRI and PET scans. Two clinical centers in the UK will be involved in the trial.

“We are excited about the positive pre-clinical data that has been obtained to date using OXi4503,” said the coordinating investigator of this trial. “The compound has shown to be highly potent in a number of animal tumor models even at doses far below the maximum tolerated dose.”

“This Phase I trial with OXi4503 is an excellent addition to our already strong clinical development program and represents a significant step forward for the Company. We are pleased to be working with the Cancer Research UK to bring this compound into clinical testing,” said Fred Driscoll, President and Chief Executive Officer of OXiGENE. “Our lead compound CA4P is currently being studied in a total of nine trials in oncology and ophthalmology and we believe that OXi4503 promises to complement and strengthen our clinical program by expanding upon the indications and therapeutic regimes already under investigation. We anticipate advancing the compound into Phase II trials in 2006.”

About OXi4503

OXiGENE believes that OXi4503 is the first in a new class of compounds known as ortho-quinone prodrugs (OQPs), which display a novel cytotoxic effect in addition to their proven vascular targeting capabilities mediated by their action on the tubulin cytoskeleton. Unlike anti-angiogenesis agents that focus on preventing new tumor blood vessels from forming, OQPs appear to attack existing blood vessel structures in the central regions of solid tumors and also have a cytotoxic effect that could enable destruction of the outside rim of cells residing next to, and dependent on, normal tissue blood vessels.

Other Recent Developments

On November 19, 2004, OXiGENE announced the initiation of a Phase II study of CA4P in patients with Myopic Macular Degeneration (MMD). In this study, CA4P is being evaluated in a multi-centered, international trial in MMD patients. This clinical trial is being conducted under OXiGENE’s first U.S. Investigational New Drug Application for a vascular targeting agent in ophthalmology.

Additionally, on December 16, 2004, OXiGENE announced the initiation of another Phase II trial of CA4P in oncology. This study in imageable solid tumors will investigate the use of CA4P in triple combination with carboplatin and paclitaxel. The initiation of this trial accelerates the development of its lead compound CA4P based on promising data from an ongoing Phase I/II study of these tumor types.

About Cancer Research UK

Cancer Research UK’s vision is to conquer cancer through world-class research. The charity works alone and in partnership with others to carry out research into the biology and causes of cancer, to develop effective treatments, improve the quality of life for cancer patients, reduce the number of people getting cancer and to provide authoritative information on cancer. Cancer Research UK is the world’s leading independent charity dedicated to research on the causes, treatment and prevention of cancer. For further information about Cancer Research UK’s work or to find out how to support the charity, please call 020 7009 8820 or visit www.cancerresearchuk.org.

About OXiGENE, Inc.

OXiGENE is an emerging pharmaceutical company developing novel small-molecule therapeutics to treat cancer and eye diseases. The Company’s major focus is the clinical advancement of drug candidates that selectively disrupt abnormal blood vessels associated with solid tumor progression and visual impairment. OXiGENE is dedicated to leveraging its intellectual property position and therapeutic development expertise to bring life saving and enhancing medicines to patients.

Safe Harbor Statement

Certain statements in this news release concerning OXiGENE’s business are considered “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995. These statements include, but are not limited to: the effect of OXi4503 on OXiGENE’s drug development opportunities, the ability of OXi4503 to have potent anti-tumor effects, the ability to advance the compound into additional trials by certain dates, the ability to obtain insight into the mechanism of action of OXi4503 and identify clinical benefit for patients, the effect of OXi4503 on the Company’s existing clinical development program, and the ability of OXi4503 to destroy the outside rim of cells. Any or all of the forward-looking statements in this press release may turn out to be wrong. They can be affected by inaccurate assumptions OXiGENE might make or by known or unknown risks and uncertainties, including, but not limited to: the early stage of product development; the ability to secure necessary patents; uncertainties as to the future success of ongoing and planned clinical trials; and the unproven safety and efficacy of products under development. Consequently, no forward-looking statement can be guaranteed, and actual results may vary materially. None of OXiGENE’s products under development have been approved for marketing by the FDA. Additional information concerning factors that could cause actual results to materially differ from those in the forward-looking statements are contained in OXiGENE’s reports to the Securities and Exchange Commission, including OXiGENE’s 10-Q, 8-K and 10-K reports. However, OXiGENE undertakes no obligation to publicly update forward-looking statements, whether because of new information, future events or otherwise.

Contact Information

Courtney Harris

Manager of Investor Relations

OXiGENE, Inc.

Contact via E-mail