OXiGENE Reports Promising Preclinical Data Using OXi4503 in Acute Myelogenous Leukemia Models at ASH Conference

Greater Antileukemic Activity Shown with OXi4503 Alone or Combined with
Bevacizumab than Bevacizumab Alone 

SOUTH SAN FRANCISCO, Calif., Dec. 7, 2009 (GLOBE NEWSWIRE) -- OXiGENE, Inc.
(Nasdaq:OXGN) (Stockholm:OXGN), a clinical-stage, biopharmaceutical company
developing novel therapeutics to treat cancer and eye diseases, today announced
the presentation of data from preclinical studies carried out by Christopher R.
Cogle, M.D., Assistant Professor, Medicine, University of Florida, senior
author on the poster. The studies were conducted in mouse xenograft and
orthotopic models of acute myelogenous leukemia (AML), and showed that OXi4503,
a second-generation, dual-action vascular disrupting agent (VDA), demonstrated
a higher level of anti-leukemic activity when administered as a single agent or
in combination with bevacizumab, an anti-VEGF antibody, than when bevacizumab
was used alone. Notably, results showed that OXi4503 alone and in combination
with bevacizumab showed more effectiveness in inducing regression of leukemic
cells in bone marrow than bevacizumab alone or placebo. The data were presented
on Saturday, December 5th, in a poster at the 2009 American Society of
Hematology conference. 

"The preclinical data presented by Dr. Cogel at ASH indicate the ability of
OXi4503 alone and in combination with bevacizumab to inhibit the microvascular
environment which promotes leukemia survival and proliferation in the bone
marrow," said Peter Langecker, M.D., Ph.D., OXiGENE's Chief Executive Officer.
"Combined with the promising preclinical and early clinical data we have
generated with OXi4503 in solid tumors, we believe that this second-generation,
dual action VDA is a valuable asset for our company and warrants continued
development. OXiGENE's intention is to advance OXi4503 in solid tumors, such as
liver cancer, and to explore strategies for optimizing the compound's potential
in AML and other forms of leukemia." 

OXi4503 Results

The data reported at ASH were presented in a poster, titled "AML Regression by
Vascular Disruption with OXi4503 and Anti-Angiogenesis with bevacizumab." 

To test the efficacy of OXi4503 in human AML, human leukemia cells were
established in mouse xenograft models. Two models were used: a subcutaneous
model and an orthotopic model where primary human leukemia cells were
established in the bone marrow. 

In the subcutaneous model, tumor bearing mice were randomly assigned to one of
four treatment groups: control, bevacizumab alone, OXi4503 alone, and
combination OXi4503 and bevacizumab. Results showed that treatment with OXi4503
significantly inhibited tumor growth and moreover, when used in combination
with bevacizumab, tumor regressions were observed. These changes in tumor
growth observed when OXi4503 was administered, either alone or in combination
with bevacizumab, were associated with significant reductions in tumor
vascularity as measured by microvessel density. 

In the orthotopic model, primary human leukemia cells were introduced
intravenously into the mice and after six weeks, once tumors had established in
the marrow, treatment was initiated. After two weeks of treatment, mice were
examined for human leukemia engraftment using flow cytometry and PCR. Leukemic
cell burden was significantly decreased by treatment with OXi4503 and
eliminated by the combination of OXi4503 with bevacizumab. 

In summary, these results indicate that OXi4503 alone or in combination with
bevacizumab produces a higher level of antitumor activity than bevacizumab
alone. The key conclusions from the study as reported by the investigators
were: 

-- In the models used in the study, bevacizumab alone does not lead to
regression of AML. 

-- In the subcutaneous AML tumor model, OXi4503 alone significantly retards
tumor growth. Furthermore, combining OXi4503 with bevacizumab leads to tumor
regression with no reactive angiogenesis. 

-- In the orthotopic model, OXi4503 alone and in combination with bevacizumab
regresses AML engraftment in bone marrow, resulting in both phenotypic and
molecular remissions. 

A copy of the poster is available on OXiGENE's website at www.oxigene.com.

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)
(fosbretabulin / CA4P), OXi4503 has been observed to block and destroy tumor
vasculature, resulting in extensive tumor cell death and necrosis. In addition,
preclinical data indicate 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 1 dose-escalation study
in patients with advanced solid tumors and as a monotherapy in a phase 1b/2a
dose-escalation study in patients with solid tumors with hepatic involvement. 

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 life-enhancing medicines to
patients. 

The OXiGENE, Inc. logo is available at
http://www.globenewswire.com/newsroom/prs/?pkgid=4969 

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, including, but not
limited to, mechanisms of anti-leukemic action of OXi4503, the potential of
OXi4503 as a single-agent therapy for certain leukemias and publication of
further corroborative OXi4503 preclinical data in AML obtained by OXiGENE's
collaborators. 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 reports on Form 10-K, 10-Q and 8-K. 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, 2008. 

CONTACT:  OXiGENE, Inc. 
          Investor and Media Contact:
          Investor Relations
          Michelle Edwards
          650-635-7006
          medwards@oxigene.com