Sep 30, 2008 (Hugin via COMTEX) -- London, UK, and Cambridge, MA: 30 September
2008 - Cancer drug developer Antisoma plc (LSE: ASM; USOTC: ATSMY) today
announced that it has started a phase II trial evaluating the addition of AS1402
to the endocrine (hormonal) therapy letrozole in post-menopausal women receiving
first-line treatment for advanced breast cancer.
Approximately 110 patients will be randomly assigned to receive either letrozole
plus AS1402 or standard treatment with letrozole alone. The safety of the
AS1402-letrozole combination will be evaluated and its efficacy compared with
that of letrozole alone. Measures of efficacy will include response rates, time
to tumour progression, progression-free survival and clinical benefit rate.
Final results are expected in 2010.
The phase II trial builds on a phase I study in patients with heavily
pre-treated breast cancer, which showed that AS1402 monotherapy was
well-tolerated and was associated with prolonged stable disease in a number of
patients.
AS1402 targets a cancer-associated form of the cell-surface protein MUC1. This
form is found in approximately 90% of breast cancers and in a wide range of
other tumours. Tissue culture studies have shown that AS1402 binds to MUC1 on
cancer cells and leads to their destruction by antibody-dependent cellular
cytotoxicity (ADCC), a process involving recruitment of the immune system.
Recent studies have shown that MUC1 up-regulates the oestrogen signalling
pathway targeted by endocrine therapies. This provides a particular rationale
for combining AS1402 with letrozole in Antisoma's phase II trial.
Hospitals in the US, Russia, Ukraine, Poland and France are taking part in the
phase II study. The trial's Principal Investigator, Professor Nuhad Ibrahim, of
the MD Anderson Cancer Center, University of Texas, said: "There is a clear
rationale for testing AS1402 in this group of breast cancer patients, and we are
pleased to be participating in this well-designed study."
Antisoma's Chief Operating Officer, Dr Ursula Ney, added: "Worldwide, over
90,000 women each year receive endocrine treatment for advanced breast cancer,
so many patients could benefit from any add-on therapy that improved outcomes in
this setting. Our phase II study rigorously tests the value of adding AS1402 to
endocrine treatment and, if positive, will provide a firm basis for progress to
a pivotal phase III trial in breast cancer."
Enquiries:
Glyn Edwards, CEO +44 (0)7909 915 Daniel Elger, Director of 068 Communications
Antisoma plc
Mark Court/Lisa Baderoon/Rebecca Skye +44 (0)20 7466 Dietrich 5000 Buchanan
Communications
Brian Korb +1 646 378 2923 The Trout Group
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 for Editors:
Background on the AS1402 phase II trial Additional details of the phase II trial
of AS1402 will be available shortly at www.clinicaltrials.gov. In this study,
the anti-MUC1 antibody AS1402 is being tested in combination with a widely used
endocrine (hormonal) therapy, letrozole, which belongs to the class of aromatase
inhibitors. This is the first study to evaluate AS1402 as part of a combination
regimen, phase I trials having tested AS1402 as a single agent. It is believed
to be the first trial to combine a MUC1-targeting antibody with endocrine
treatment for cancer. Endpoints in the phase II trial include response rates,
time to tumour progression, progression-free survival and clinical benefit rate
(sum of patients showing a response or disease stabilisation by 'RECIST'
(Response Evaluation Criteria In Solid Tumours)).
Background on AS1402 AS1402 (huHMFG1, previously known also as R1550 and Therex)
is a humanised antibody against a form of MUC1 found on the surface of various
cancers. The drug has successfully completed phase I studies in breast cancer.
It was licensed by Antisoma from the Imperial Cancer Research Technologies, the
technology transfer arm of the Imperial Cancer Research Fund (now Cancer
Research UK).
AS1402 is a humanised antibody that attacks cancer cells by recruiting the
patient's immune system, particularly natural killer cells. This is the process
of antibody-dependent cellular cytotoxicity (ADCC), which has been demonstrated
during experiments in vitro with the AS1402 antibody. A growing body of evidence
links the MUC1 protein targeted by AS1402 with cancer progression and
metastasis. In particular, MUC1 has been implicated in changes in intracellular
signalling and altered interactions with extracellular matrix components such as
ICAM-1. These findings reinforce the relevance of MUC1 as a target for
anti-cancer treatments and open up the possibility that, in addition to
mediating ADCC, naked anti-MUC1 antibodies such as AS1402 may exert effects on
cancer cells by altering the interactions of MUC1 with other proteins.
Background on Antisoma Antisoma is a London Stock Exchange-listed
biopharmaceutical company that develops novel products for the treatment of
cancer. The Company has operations in the UK and the US. Please visit
www.antisoma.com for further information about Antisoma.
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SOURCE: Antisoma plc
Copyright (c) 2008, HUGIN AS. All rights reserved.
KEYWORD: UK
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ORGANIZATION: Antisoma plc
