OXiGENE Abstracts Published in ASCO Program

OXiGENE Abstracts Published in ASCO Program

--  Phase II Combretastatin A4 Phosphate / CA4P study with
    paclitaxel and carboplatin shows safety, anti-tumor activity,
    and reduced blood flow

--  Phase I study of OXi4503 demonstrates safety without reaching
    dose-limiting toxicity; changes in functional activity
    observed; study ongoing

    WALTHAM, Mass.--(BUSINESS WIRE)--June 1, 2007--OXiGENE, Inc.
(NASDAQ: OXGN, XSSE: OXGN), a clinical-stage biopharmaceutical company
developing novel therapeutics to treat cancer and eye diseases,
announced today the publication of two abstracts in the 2007 Annual
Meeting program distributed this afternoon at the Annual Meeting of
the American Society of Clinical Oncology (ASCO) in Chicago, IL.

    The first abstract reports for the first time full data from a
randomized Phase II trial of Combretastatin A4 Phosphate / CA4P
(trademarked by OXiGENE as ZYBRESTAT(TM)) in combination with
paclitaxel and carboplatin. In the abstract, lead author Dr. Wallace
L. Akerley of the Huntsman Cancer Institute reports that the two dose
regimens of CA4P studied, 45 mg/m2 and 63 mg/m2 in combination with
paclitaxel and carboplatin, were well tolerated, demonstrated
anti-tumor activity and reduced tumor blood flow by 46% and 19%,
respectively. Tumor responses were observed and were similar between
both dose groups, and the best overall response through cycle 6 was
three partial responses (PR) and six stable disease (SD) responses as
measured by RECIST criteria. Notably, the two patients with anaplastic
thyroid cancer (ATC), the lead indication for ZYBRESTAT, achieved the
greatest reductions in tumor blood flow (Ktrans of 73% and 79%). The
study enrolled 13 patients with advanced imageable malignancies, and
imaging evaluations were carried out using DCE-MRI, a standard imaging
modality used to evaluate tumor blood flow and perfusion. DCE-MRI
evaluations were performed prior to and 24 hours following the first
dose of ZYBRESTAT. Interim data for this study was previously reported
in September 2006 at The Tumor Microenvironment 10th International
Workshop.

    The second abstract reports for the first time initial data from
early dosing cohorts in a Phase I study of OXi4503 in patients with
advanced solid tumors. Lead author Dr. Daniel M. Patterson of the
Mount Vernon Cancer Centre indicates that while the study had not yet
reached maximum tolerated dose and recruitment is ongoing, the data to
date suggest that OXi4503 is tolerated at doses up to 5 mg/m2 without
dose-limiting toxicity. Changes in functional activity, as assessed
with DCI-MRI and PET imaging evaluations, were observed in three of
the eleven patients studied. OXi4503 is a novel, second-generation
vascular disrupting agent with potential intrinsic cytotoxicity
exerted through an ortho-quinone metabolite. The drug candidate is
being evaluated in this Phase I dose escalation and safety study.
Based on results to date, OXiGENE currently anticipates initiating
further clinical studies with OXi4503 in 2007.

    About Combretastatin A4 Phosphate/CA4P (ZYBRESTAT) and OXi4503

    ZYBRESTAT is poised to become the first therapeutic product in a
novel class of small-molecule drug candidates called vascular
disrupting agents (VDAs). The Company currently anticipates starting a
Phase II/III pivotal registration study with ZYBRESTAT in June 2007
under a Special Protocol Assessment agreement with the US Food and
Drug Administration. Via interaction with vascular endothelial cell
cytoskeletal proteins, ZYBRESTAT selectively targets and collapses
tumor vasculature, thereby depriving the tumor of oxygen and causing
death of tumor cells. ZYBRESTAT has demonstrated potent and selective
activity against tumor vasculature, as well as substantial clinical
activity against ATC and other solid tumors in clinical studies to
date. Our strategy for optimizing the antitumor activity of ZYBRESTAT
is to combine it with other types of therapeutic modalities, including
cytotoxic drugs, anti-angiogenesis drugs, and radiation therapy. The
rationale for combining ZYBRESTAT with other therapeutic modalities
stems from the hypothesis that agents with different and potentially
complimentary mechanisms of action and with a non-overlapping toxicity
profile may achieve synergistic antitumor activity when administered
concurrently. In animal studies, ZYBRESTAT has been shown to enhance
the anti-tumor effects of several chemotherapeutic agents, several
anti-angiogenic drugs, and radiation.

    OXi4503 is a novel, second-generation vascular disrupting agent
with potential intrinsic cytotoxicity exerted through an ortho-quinone
metabolite. The drug candidate has demonstrated single-agent activity
in human tumor xenograft models. Preclinical research with OXi4503
suggests that it not only shuts down tumor blood flow, but can also be
metabolized into a compound which could assist with killing the
remaining tumor cells at the periphery of the tumor by direct
cytotoxic activity against tumor cells. In December 2004, the United
Kingdom regulatory authorities accepted an application from our
collaborators, Cancer Research UK, to initiate a dose-escalating Phase
I clinical trial of OXi4503 in patients with advanced cancer. This
trial is currently ongoing. In 2007, OXiGENE plans to initiate several
preclinical studies to evaluate OXi4503 and possibly a Phase Ib
clinical trial of OXi4503 in combination with an approved
anti-angiogenic therapeutic.

    About OXiGENE, Inc.

    OXiGENE is a clinical-stage biotechnology 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

    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
including the initiation of further clinical trials with OXi4503, the
effects of combining ZYBRESTAT with other therapeutic modalities,
additional mechanisms of action of OXi4503 and the safety and efficacy
of our potential product candidates, ZYBRESTAT and OXi4503 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-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. Please refer to our Annual
Report on Form 10-K for the fiscal year ended December 31, 2006 for a
description of these risks.

CONTACT: OXiGENE, Inc.
         Investor Relations, 781-547-5900