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

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

    WALTHAM, Mass.--(BUSINESS WIRE)--Oct. 24, 2007--Regulatory News:

    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
http://pubs.acs.org/journals/crtoec/index.html.) 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
www.oxigene.com 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
(http://pubs.acs.org/cgi-bin/abstract.cgi/crtoec/
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.

    About OXiGENE

    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.


CONTACT: OXiGENE, Inc.
             Shari Annes, 650-888-0902
             Investor Relations
             sannes@oxigene.com