Researchers demonstrate direct anti-tumor effect of
               Combretastatin and show advances in development of
                            a new gene therapy model

        Data presented at 17th Annual Meeting of the European Society for
                       Therapeutic Radiology and Oncology

     Edinburgh,  Scotland, September 23, 1998. OXiGENE, Inc. (Nasdaq: OXGN, SSE:
OXGN),  an  international   biopharmaceutical   company,  announced  today  that
researchers  from  University  Hospital  GHB,  KU Leuven,  Belgium  reported  on
pre-clinical data demonstrating that Combretastatin A-4 prodrug (Combretastatin)
had a striking direct  anti-tumor  effect directed against rat  rhabdomyosarcoma
tumors  and it was also used to create a hypoxic  (low  oxygen)  environment  in
which anaerobic bacteria carrying  tumor-killing  proteins  flourished.  Data on
Combretastatin,  a vascular  targeting  agent being  developed  by OXiGENE,  was
presented  at the 17th Annual  Meeting of the European  Society for  Therapeutic
Radiology and Oncology (ESTRO).

     Willy  Landuyt,   Ph.D.,   and  his  colleagues   from  the  Department  of
Experimental  Radiobiology/Oncology  at University  Hospital are investigating a
model of  genetic  therapy  for tumor drug  targeting  that  utilizes  anaerobic
bacteria to deliver  recombinant  proteins  capable of converting  safe prodrugs
into  cytotoxic  drugs  specifically  to a tumor site.  The bacteria,  which are
injected  into  the  body  with  the  aim  of  causing  bacterial  proliferation
specifically  in the tumor - but no where  else - can only  thrive in a state of
hypoxia, or decreased oxygen. Dr. Landuyt reported that a single dose of 25mg/kg
Combretastatin  injected into rats with  rhabdomyosarcoma  tumors caused massive
shutdown of tumor blood vessels,  successfully inducing hypoxia within tumors of
varying size and allowing  anaerobic  bacteria to proliferate within the tumors.
The  Combretastatin-induced  hypoxia will be used to further test this model and
to potentially develop the anaerobic vector for use in targeted gene therapies.

     "We are very excited about Combretastatin's ability to shut down blood flow
to  tumors,  which  resulted  in the  hypoxic  state  needed to allow  anaerobic
bacteria to flourish specifically at the tumor site," says Dr. Landuyt. "The use
of Combretastatin  will enable us to advance the use of anaerobic  bacteria as a
targeted vector for gene therapy,  of which  investigations are in progress.  In
addition,  the anti-tumor effect of Combretastatin  observed in our study speaks
to the impressive action of this particular  compound,  and the promise it holds
to be a powerful anti-cancer agent."

     Combretastatin  is the  first in a new  class of tumor  vascular  targeting
drugs that are intended to selectively attack and destroy  tumor-specific  blood
vessels formed by  angiogenesis,  resulting in a massive rapid and  irreversible
shutdown of these blood  vessels  while  leaving  normal  vasculature  unharmed.
OXiGENE  plans to  clinically  develop  Combretastatin  as a stand alone therapy
which could be used in combination with other  therapies.  Phase I/II studies of
Combretastatin  in patients with advanced stage cancers in the United States and
Europe are scheduled for the second half of 1998.

     OXiGENE  is  an  international   biopharmaceutical   company  developing  a
portfolio of innovative products to combat cancer and other major diseases.  The
Company  currently  has  four  products  in  clinical   development,   including
Neu-Sensamide,  being tested as a radiosensitizer in Phase II and III studies in
patients with non-small cell lung cancer and in a Phase I study in patients with
glioblastoma; OXi-104 (declopramide), being tested as a chemosensitizer in Phase
I/II studies in patients with advanced stage cancers;  Cordycepin, which is in a
Phase I/II study in patients with TdT-positive  leukemia; and Combretastatin A-4
prodrug,  a vascular targeting agent expected to enter Phase I/II studies in the
second half of 1998.

     This press release  contains  forward-looking  statements that involve
risks and  uncertainties  that may cause the  Company's  actual  results or
outcomes to be materially different from those anticipated and discussed in
this press release.  Factors that may cause such a difference include,  but
are not  limited  to,  those risks and  uncertainties  associated  with the
regulatory  approval of the Company's  proprietary  drugs,  and other risks
included in the  Company's  Annual Report on Form 10-K and in the Company's
other filings with the Securities and Exchange  Commission  during the past
12 months. Specifically, there can be no assurance that Combretastatin will
meet the  expectations  of those who are  testing  it or will prove to have
commercial acceptance.