RNS Number:9591S
Antisoma PLC
08 December 2003

Positive data on Antisoma's AS1406 presented at ASH

Findings from US National Cancer Institute support Antisoma's plans for blood
cancer trials


8 December 2003, London, UK (LSE:ASM): Data presented yesterday at the American
Society of Hematology  (ASH) meeting show that AS1406 significantly prolongs
survival in mice carrying human blood cancers known as lymphomas. The findings
support Antisoma's plans to accelerate the progress of AS1406 into clinical
trials and to broaden the trials programme to include blood cancer indications
as well as solid tumours. These plans were highlighted as one of four key
programmes to strengthen Antisoma's pipeline when the Company announced a #15.2
million placing and open offer on 25 November.


The AS1406 studies were carried out by Professor Susanna Rybak at the United
States National Cancer Institute under a Collaborative Research and Development
Agreement with Antisoma. Dr Nigel Courtenay-Luck, Antisoma's Chief Scientific
Officer, presented the findings. In one experiment mice with advanced lymphomas
received AS1406 or a control for five days. The drug extended median survival
from 33 to 59 days. Whereas all animals had died by day 34 in the control group,
more than 20% of those receiving AS1406 were still alive when the experiment
ended after 77 days.


AS1406 is the most advanced drug in Antisoma's targeted apoptosis programme,
which combines cancer-targeting antibodies with enzymes able to trigger the
cellular self-destruct pathway known as apoptosis.  Positive data on AS1406 were
previously reported for solid tumours: in a breast cancer model the drug
inhibited the growth of primary tumours and reduced their capacity to spread to
new sites by metastasis.  Extension of positive findings to a major blood cancer
such as lymphoma broadens the potential application of the drug considerably.


Professor Susanna Rybak, the lead researcher on the RNase programme said: 
"Findings in our lymphoma model strongly support the inclusion of blood cancer
indications in the forthcoming clinical trials programme for AS1406."


Glyn Edwards, Chief Executive Officer of Antisoma, added: "Targeted apoptosis is
much closer to a magic bullet than most current cancer therapies. We are making
good progress in preparing AS1406 for clinical trials and are delighted that
work done at the NCI has demonstrated the potential for the drug in the
multi-billion dollar lymphoma market."



Enquiries:


Antisoma plc
Daniel Elger,                                          Tel: +44 (0)20 8799 8200
Head of Corporate Communications

Financial Dynamics
Ben Atwell                                             Tel: +44 (0)20 7831 3113



Except for the historical information presented, certain matters discussed in
this statement are forward looking statements that are subject to a number of
risks and uncertainties that could cause actual results to differ materially
from results, performance or achievements expressed or implied by such
statements. These risks and uncertainties may be associated with product
discovery and development, including statements regarding the Company's clinical
development programmes, the expected timing of clinical trials and regulatory
filings. Such statements are based on management's current expectations, but
actual results may differ materially.



Notes to Editors


RNase and targeted apoptosis

AS1406 is the antibody humanised HMFG1 linked to the enzyme recombinant
cytotoxic RNase. HMFG1 targets a protein called MUC1 that is expressed on the
surface of cancer cells in many solid tumours and a variety of blood cancers.
When the antibody binds to MUC1 it releases the RNase enzyme into the cancer
cell, prompting the cell to 'commit suicide' by apoptosis.  Antisoma has
exclusive worldwide rights to use the RNase enzyme in combination with
monoclonal antibodies that target MUC1 and another protein found on certain
cancer cells, mCEA (membrane bound carcino-embryonic antigen). These rights were
acquired through an in-licensing agreement with the US National Institutes of
Health (NIH) announced in September 2001. Rights have been extended to cover use
in lymphoma and myeloma as well as solid tumours. The technology is covered by a
number of granted US patents, and equivalent patents have been filed in Europe
and other territories.


Antisoma has been funding research into the combined use of antibodies and RNase
by Prof Rybak at the Frederick Cancer Research and Development Center, National
Cancer Institute, in Maryland, USA since 1999.


About Antisoma

Based in London, UK, Antisoma is a biopharmaceutical company that develops novel
products for the treatment of cancer. The Company fills its development pipeline
by acquiring promising new product candidates from internationally recognised
academic or cancer research institutions.  Its core activity is the preclinical
and clinical development of these drug candidates. Antisoma forms partnerships
with pharmaceutical companies to bring its products to market.  In November
2002, Antisoma formed a broad strategic alliance with Roche to develop and
commercialise products from Antisoma's pipeline. Please visit www.antisoma.com
for further information about Antisoma.


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