OXiGENE to Commence First Ever Oncology Clinical Trial Combining a Vascular Disrupting Compound, Combretastatin A4P, with an Anti-Angiogenic Agent, Avastin

-- Dose-Escalating Study Will Commence to Assess the Safety, Tolerability and Anti-Tumor Effects of a Promising New Potential Treatment for People with Advanced Solid Tumors

-- Strong Preclinical Research Pairing Vascular Disrupting and Anti-Angiogenic Agents Showed Definitive Biological Activity; Significant Anti-Tumor Activity Observed from Combined Therapies Targeted at the Tumor Vasculature

OXiGENE, Inc. (NASDAQ: OXGN, XSSE: OXGN), a leading developer ofbiopharmaceutical compounds designed to treat cancer and certainophthalmologic diseases, today announced that it will initiate a newclinical trial with its lead vascular disrupting compound,Combretastatin A4 Phosphate (CA4P). The Company will commence a PhaseIb clinical study to evaluate CA4P in combination therapy withAvastin(R) (Bevacizumab), a drug that is owned and marketed byGenentech (NYSE: DNA). The Phase Ib clinical trial follows previouslyannounced preclinical data presented at a recent conference of theAmerican Association for Cancer Research (AACR/NCI/EORTC) which showedthat the combination of CA4P with the anti-angiogenic drug, Avastin,produced significant anti-tumor activity and could offer a powerfuland highly targeted treatment strategy for fighting solid tumors. Thiswill be the first human clinical trial to pair a vascular disruptingcompound and an anti-angiogenic agent in the treatment of cancer,specifically in people who have failed previous treatment and who arein advanced stages of disease.

This trial is an important strategic complement to the breadth ofstudies evaluating CA4P in combination therapy in oncology, and itconfirms OXiGENE's lead clinical position as the first developer ofVDAs to pair a small molecule with chemotherapy, radiotherapy, andnow, anti-angiogenic therapy.

"Preclinical models continue to support the theory that thecombination of compounds targeted toward tumor vasculature could havea profound anti-tumor effect in humans," stated David Chaplin, Ph.D.,Chief Scientific Officer and Head of Research and Development atOXiGENE. "In addition, we believe the complementary action of a VDAwith anti-angiogenic approaches may have utility not only in cancer,but in other diseases where abnormal new vessel growth underlies thedisease pathology."

In recent preclinical studies that examined the efficacy ofcombining Avastin with CA4P in a human renal cell carcinoma model(Caki-1), CA4P was shown to enhance the effect of Avastin. The datashowed that treatment with Avastin or CA4P alone resulted in tumorgrowth delays of 8 days and 6 days, respectively. The data also showedthat CA4P was effective at causing extensive vasculature damage andtumor cell death in the central regions of solid tumors. However, whenCA4P was administered in combination with Avastin, statisticallysignificant, enhanced anti-tumor effects were observed: Thecombination of CA4P plus Avastin led to a tumor growth delay of 13days--an increase of approximately 61 per cent in the effectiveness ofAvastin.

The enhanced anti-tumor effect achieved from combining thesecompounds in this preclinical model may correlate to the complementaryapproaches of each compound. OXiGENE's CA4P is a novel, small moleculevascular disrupting agent that causes massive and rapid tumor death bydisrupting the function of abnormal blood vessels that support tumorgrowth and survival. CA4P causes extensive destruction of centralregions of tumors--areas that are believed to contain cells that areresistant to most conventional therapies, such as chemotherapy andradiation. Avastin, by contrast, is a recombinant humanized antibodyto Vascular Endothelial Growth Factor (VEGF). Avastin is designed tobind to and inhibit VEGF, a protein that plays a critical role intumor angiogenesis (the formation of new blood vessels to the tumor).OXiGENE believes that combining these compounds could ultimately offera new and viable cancer treatment strategy that destroys a tumor bytargeting not only new blood vessel growth, but also by razing thealready established tumor blood vessel network.

The FDA, in February 2004, approved Avastin for use in combinationwith intravenous 5-Fluorouracil-based chemotherapy as a treatment forpatients with first-line--or previously untreated--metastatic cancerof the colon or rectum. Genentech is pursuing a broad late-stageclinical development program with Avastin, evaluating its potentialuse in multiple tumor types. Phase III clinical trials in adjuvantcolorectal cancer, renal cell carcinoma, prostate cancer, andmetastatic and locally advanced pancreatic cancer are being conducted.Genentech reports that a Phase III trial in first-line ovarian canceris planned. (1)

OXiGENE's Phase Ib combination trial with Avastin will be atraditional open-label, multi-center trial designed to determine thesafety and tolerability of ascending doses of CA4P administeredintravenously in combination with Bevacizumab. Dosing levels of CA4Pwill be escalated until a maximum tolerated dose is achieved.Anti-tumor effects and tumor response will be evaluated using theinternational standard for oncology clinical trials, known as ResponseEvaluation Criteria In Solid Tumors (RECIST). Pharmacodynamic effectsto assess blood flow shutdown to the tumor will be assessed withMagnetic Resonance Imaging (MRI).

"We believe that the results from this trial could have a profoundimpact on the development of therapeutic approaches to treat cancer bytargeting the abnormal vasculature associated with solid tumors," saidFrederick Driscoll, President and Chief Executive Officer at OXiGENE."With Genentech's approval for Bevacizumab for the treatment ofcolorectal cancer, as well as the myriad of trials investigating itsuse for solid tumor types such as renal cell carcinoma, pancreaticcancer and others, we are hopeful that this combination will have apotentially dramatic impact on cancer treatment therapies."

About Combretastatin A4P (CA4P)

CA4P leads a novel class of small molecule drug candidates calledvascular disrupting agents (VDAs). CA4P works via two potentiallysynergistic processes that selectively target pericyte-depletedneovessels, which lack ensheathment from smooth muscle support cells.CA4P is a potent and reversible tubulin depolymerizing agent thatcauses newly formed endothelial cells that line blood vessels tochange shape, round up and detach from the vessel wall. Recentpreclinical research has also shown that CA4P disrupts the molecularengagement of VE-cadherin, a junction protein important forendothelial cell survival and function, and inhibits the associatedbeta-catenin/AKT signaling pathway, leading to rapid vascularcollapse and necrosis. These complementary mechanisms block the flowof blood to a tumor and deprive it of oxygen and nutrients essentialto its survival. Similarly, in eye diseases that are characterized byabnormal blood vessel growth, CA4P has been shown in preclinicalstudies to suppress development and induce regression of theseunnecessary blood vessels.

The commencement of this Phase Ib clinical trial brings to seventhe total number of actively enrolling clinical studies evaluatingCA4P in oncology. These clinical trials involve the use of CA4P inboth single-agent and combination therapies including a Phase II trialevaluating CA4P in combination with carboplatin/paclitaxel for thetreatment of platinum-resistant ovarian cancer, as well as a PhaseIb/II trial studying CA4P in combination with radiotherapy. The leadinvestigators of this trial recently reported synergistic effects withCA4P and radiotherapy, as well as evidence of sustained blood flowshutdown to tumors, and side effects in patients that are mild andself-limiting. CA4P is also being studied in a Phase II clinical trialin myopic macular degeneration.

About OXiGENE, Inc.

OXiGENE is an emerging pharmaceutical company developing novelsmall-molecule therapeutics to treat cancer and eye diseases. TheCompany's major focus is the clinical advancement of drug candidatesthat selectively disrupt abnormal blood vessels associated with solidtumor progression and visual impairment. OXiGENE is dedicated toleveraging its intellectual property position and therapeuticdevelopment expertise to bring life saving and enhancing medicines topatients.

Footnotes:

(1) www.genentech.com

Safe Harbor Statement

This news release contains "forward-looking statements" within themeaning of the Private Securities Litigation Reform Act of 1995. Anyor all of the forward-looking statements in this press release mayturn out to be wrong, including statements regarding the therapeuticefficacy and future success of CA4P either in single agent therapy orin combined therapy with Avastin or other compounds or therapies intreating cancer; the potential of CA4P to inhibit tumor growth eitheras a single agent or in combination therapy; and, the capabilities ofCA4P to cause significant anti-tumor effects as a single-agent and incombination with other therapies. Forward-looking statements can beaffected by inaccurate assumptions OXiGENE might make or by known orunknown risks and uncertainties. Additional information concerningfactors that could cause actual results to materially differ fromthose in the forward-looking statements is contained in OXiGENE'sreports to the Securities and Exchange Commission, including OXiGENE'sForm 10-Q, 8-K and 10-K reports. However, OXiGENE undertakes noobligation to publicly update forward-looking statements, whetherbecause of new information, future events or otherwise. Please referto our Annual Report on Form 10-K for the fiscal year ended December31, 2004 for a description of these risks.

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