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OXiGENE Reports OXi4503 Phase I Interim Data; Mechanism-of-Action Data Published in Peer-Review Journal

WALTHAM, Mass.--(BUSINESS WIRE)--Oct 24, 2007 - OXiGENE, Inc. (NASDAQ: OXGN, XSSE: OXGN), a clinical-stage, biopharmaceutical company developing novel therapeutics to treat cancer and eye diseases, today presented interim results from an ongoing Phase I dose-escalation study of its oncology product candidate OXi4503 at the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics in San Francisco, CA. Separately, OXiGENE indicated that results from mechanism-of-action studies involving OXi4503 were published on the website of Chemical Research in Toxicology in advance of the journal's print version. (See OXi4503 (combretastatin A1 phosphate) is a dual-mechanism vascular disrupting agent (VDA) that OXiGENE is developing as a second-generation, follow-on to its lead VDA product candidate, ZYBRESTAT(TM), which is currently being evaluated in a pivotal registration study in anaplastic thyroid cancer under a Special Protocol Assessment agreement with the U.S. Food and Drug Administration (FDA).

Interim OXi4503 Phase I Results Update ASCO 2007 Data

As reported in a poster presentation by Dr. Dan Patterson and colleagues from Cancer Research UK, OXi4503 was observed to be well tolerated with no dose-limiting toxicity seen to date at dosages now corresponding to maximum-tolerated dosages in preclinical studies. Tumor blood flow shutdown and metabolic inactivation have been observed with MRI and PET imaging, and disease stabilization (stable disease per RECIST criteria) has been achieved in several subjects.

The poster (#714 / Abstract #B7), "Interim results from a phase I trial of the vascular disrupting agent OXi4503," is being presented today in the Exhibit Hall (First Floor, Moscone Convention Center West), from 12:30-2:30 p.m. PDT and 5:30-7:30 p.m. PDT in the Antiangiogenic/Antivascular Agents Poster Session B. The data reported today update results from the ongoing Phase I dose-escalation study initially reported at the June 2007 ASCO meeting in Chicago, IL.

The ongoing OXi4503 Phase I study is an open-label, dose-escalation study designed to determine maximum tolerated dose, toxicity profile, pharmacokinetic and pharmacodynamic behavior, and functional / biological activity of the product candidate in patients with advanced solid tumors. A copy of the poster will be available at under Press Room / Publications.

OXi4503 Mechanism-of-Action Study Results Published in Chemical Research in Toxicology

An article by lead author Lisa K. Folkes from the University of Oxford's Gray Cancer Institute describes the mechanism-of-action by which OXi4503 may exert direct cytotoxic effects on tumor cells. OXiGENE believes this direct cytotoxic mechanism is unique among VDAs and is additive to the vascular-disrupting activity also exhibited by OXi4503. Entitled "Oxidative Metabolism of Combretastatin A-1 Produces Quinone Intermediates with the Potential To Bind to Nucleophiles and To Enhance Oxidative Stress via Free Radicals," the article has been published ahead of print in electronic form on the website of the journal Chemical Research in Toxicology ( asap/abs/tx7002195.html). (Due to the length of this URL, it may be necessary to copy and paste it into your Internet browser's URL address field. You may also need to remove an extra space in the URL if one exists.)

About OXi4503

OXi4503 (combretastatin A1 di-phosphate / CA1P) is a dual-mechanism vascular disrupting agent (VDA) that is being developed in clinical studies for the treatment of solid tumors. Like its structural analog, ZYBRESTAT(TM) (combretastatin A4 phosphate / CA4P), OXi4503 has been observed to block and destroy tumor vasculature, resulting in extensive tumor cell death and necrosis. In addition, preclinical data indicates that OXi4503 is metabolized by oxidative enzymes (e.g., tyrosinase and peroxidases), which are elevated in many solid tumors and tumor white blood cell infiltrates, to an orthoquinone chemical species that has direct cytotoxic effects on tumor cells. Preclinical studies have shown that OXi4503 has (i) single-agent activity against a range of xenograft tumor models; and (ii) synergistic or additive effects when incorporated in various combination regimens with chemotherapy, molecularly-targeted therapies (including tumor-angiogenesis inhibitors), and radiation therapy.

OXi4503 is currently being evaluated as a monotherapy in a Phase I dose-escalation study in patients with advanced solid tumors.


OXiGENE is a clinical-stage biopharmaceutical company developing novel therapeutics to treat cancer and eye diseases. The company's major focus is developing vascular disrupting agents (VDAs) that selectively disrupt abnormal blood vessels associated with solid tumor progression and visual impairment. OXiGENE is dedicated to leveraging its intellectual property and therapeutic development expertise to bring life-extending and -enhancing medicines to patients.

Safe Harbor Statement

This news release contains "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act of 1995. Any or all of the forward-looking statements in this press release may turn out to be wrong. Forward-looking statements can be affected by inaccurate assumptions OXiGENE might make or by known or unknown risks and uncertainties. Additional information concerning factors that could cause actual results to materially differ from those in the forward-looking statements is contained in OXiGENE's reports to the Securities and Exchange Commission, including OXiGENE's Form 10-K, 10-Q and 8-K reports. However, OXiGENE undertakes no obligation to publicly update forward-looking statements, whether because of new information, future events or otherwise. Please refer to our Annual Report on Form 10-K for the fiscal year ended December 31, 2006.


Shari Annes, 650-888-0902
Investor Relations

Posted: October 2007