Avantogen Receives Milestone Payment from Endocyte for GPI Vaccine Adjuvant; Company Also Receives European Patent and Commences

Avantogen, Ltd. (ASX:ACU), formerly Australian Cancer
Technology, today announced that Endocyte, Inc. will pay its first
milestone payment to the Company for Avantogen's successful submission
of a Drug Master File (DMF) to the U.S. Food and Drug Administration
(FDA) for its proprietary vaccine adjuvant GPI-0100. Avantogen
announced the submission of the DMF on April 7, 2005 in Australia.
Endocyte is Avantogen's partner and licensee for the use of GPI-0100
in an immunotherapy for kidney cancer.
   Endocyte is currently conducting a multi-center, open-label,
baseline-controlled, dose-ranging Phase I clinical study of an
investigational targeted immunotherapy using GPI-0100. The study is
designed to evaluate the safety and pharmacokinetics of the
immunotherapy regimen. Endocyte's novel targeted immunotherapy is
comprised of GPI-0100 adjuvant and a folate-conjugated molecule (EC17)
that targets folate receptor positive tumor cells to potentially
enhance tumor cell removal by cytokine stimulated immune cells. The
over-expression of the folate receptor occurs in a number of
malignancies, including kidney and ovarian cancers.
   "This is the first milestone payment that we've received for
GPI-0100, and it validates our commercialization strategy for this
exceptional adjuvant," said Leonard Firestone, MD, CEO of Avantogen.
"We expect additional milestone payments from other licensees,
including Pfizer Animal Health Division, in the near future. We
anticipate that other companies will soon adopt GPI-0100 as their
preferred vaccine adjuvant."

   More GPI Adjuvant Progress

   This key milestone follows the granting of European patent number
0996451 entitled "Triterpene Saponin Analogs having Adjuvant and
Immunostimulatory Activity". The patent provides protection around the
Company's immune-enhancing adjuvant GPI-0100 and its use as a
component in vaccines and the initiation of preclinical trials for the
use of GPI-0100 in a potential vaccine to the Herpes Simplex Virus
(HSV-2) in European Union countries.
   Additionally, Avantogen recently announced that, together with the
University of Alabama at Birmingham (UAB), the Company has commenced
preclinical studies using GPI-0100 as an adjuvant to increase the
immune response to a new vaccine designed to reduce the recurrence and
shorten the duration of herpetic lesions caused by the Herpes Simplex
Virus (HSV-2). The research will be conducted at UAB under the
direction of Earl R. Kern, Ph.D., Research Professor at UAB's
Department of Pediatrics and a recognized expert in the area of Herpes
viruses.
   Adjuvants boost the physiologic response to a foreign substance by
stimulating the immune system. GPI-0100, which Avantogen acquired from
Galenica in 2004, is a modified, semi-synthetic saponin, a naturally
occurring plant detergent or surfactant. The saponin upon which
GPI-0100 is based occurs in the bark of a South American tree.
GPI-0100 has been shown to stimulate both the antibody and cellular
components of the immune system, and modifications made to the
molecule increase its stability and safety profile versus naturally
occurring saponins.

   About Avantogen

   Avantogen (formerly Australian Cancer Technology) is an
international biotechnology company developing a broad
oncology-related product portfolio. Avantogen is developing RP101, an
exceptionally promising pancreatic cancer drug currently in Phase II
clinical studies, through a joint venture with Bioaccelerate of New
York. Avantogen's Pentrys(TM) anti-cancer vaccine is undergoing phase
IIb clinical trials in prostate cancer patients, and the Company is
advancing a family of immune-enhancing adjuvants which has been in
three Phase I cancer trials in the United States. The company has also
marketed Revisys(TM), a branded line of medical nutritionals
specifically developed to address special nutritional needs, such as
those following cancer treatments. Avantogen is traded on the
Australian Stock Exchange (ASX) under the symbol ACU. The Company has
established a Level 1 ADR stock program in the U.S. trading under the
symbol AUCJY and also is listed on the Xetra exchange, the electronic
trading system of the Frankfurt Stock Exchange, trading under the
symbol CBS.

   About Endocyte

   Endocyte is an innovative biotechnology company developing a new
generation of receptor-targeted therapeutics or "smart drugs" for the
treatment of cancer and autoimmune diseases. Current non-targeted
drugs are usually toxic to normal healthy cells causing side effects,
some of which can be serious and/or fatal. These side effects can lead
to suboptimal dosing in order to minimize toxicities. The company's
initial development focus is on a receptor for the vitamin folic acid,
which is often over-expressed in cancer cells. Animal studies have
shown that drugs targeted with folic acid have less toxicity, allowing
for more frequent dosing and improved efficacy. Endocyte currently has
two compounds in clinical trials -- EC20, a targeted diagnostic agent
that has been evaluated in phase 2 studies and EC17, a targeted
immunotherapy that is currently being evaluated in phase 1 studies.
Its third targeted drug, EC145, will begin Phase I testing early next
year. Endocyte is committed to building value by building a rich
product pipeline through its own development programs and through
multiple collaborations with pharmaceutical and biotechnology
companies and universities.

   Forward-Looking Statements

   Statements contained in this press release that are not historical
information are forward-looking statements as defined within the
Private Securities Litigation Reform Act of 1995. Such forward-looking
statements are subject to risks and uncertainties that could cause
Avantogen's ("Company") actual results to differ materially from those
projected or implied. Such potential risks and uncertainties relate,
but are not limited, to the results of clinical trials, product demand
and market acceptance, the impact of competitive products and pricing,
effectiveness and pace of current and future product development, and
regulatory approval. More detailed information on these and additional
factors that could affect the Company's operating and financial
results are described in the Company's annual reports filed or to be
filed with the Australian Stock Exchange. The Company urges all
interested parties to read these reports to gain a better
understanding of the many business and other risks that the Company
faces. The historical results achieved by the Company are not
necessarily indicative of its future prospects. The Company undertakes
no obligation to publicly update or revise any forward-looking
statements, whether as a result of new information, future events or
otherwise.