Antisoma encouraged by ASA404 prostate cancer data
London, UK: 15 October 2007 - Antisoma plc (LSE: ASM; US OTC: ATSMY)
today announces that it has received further data from its 74-patient
randomised phase II trial of ASA404 in hormone-refractory prostate
cancer. This trial compares patients receiving 1200 mg/m2 ASA404 plus
docetaxel with patients receiving docetaxel alone:
* PSA response rates were markedly higher in patients receiving
ASA404 (59% vs 37% with docetaxel alone, as previously reported)
* Tumour response rates in patients assessable by RECIST were
higher in patients receiving ASA404
* Time to disease progression was marginally longer in patients
* Survival data are immature; follow-up continues and median
survival data are expected in the second half of 2008
* Safety findings from the trial suggest that addition of ASA404 to
chemotherapy was generally well tolerated.
Overall, findings to date with ASA404 in prostate cancer are
encouraging, but longer term data will be needed to evaluate the full
potential of the compound for this indication. Further development of
ASA404 in prostate cancer will be managed by Novartis.
Antisoma has been testing ASA404 in several cancer types. Studies in
lung cancer have produced positive results, including a 5-month
improvement in median survival in a randomised study. Novartis plans
to start enrolling patients into a phase III trial in non-small cell
lung cancer early in 2008.
Glyn Edwards, Antisoma's CEO said, "We've had some encouraging early
findings from our ASA404 prostate cancer study, and now look forward
to seeing the survival outcomes next year. In the meantime, the
immediate focus is on the drug's lead indication, lung cancer, where
a phase III trial is scheduled to start early next year based on
strong phase II data."
Details of the prostate cancer findings will be submitted for
presentation at a major cancer conference in 2008.
Glyn Edwards, Chief Executive Officer
Daniel Elger, Director of Communications +44 7909 915 068
Mark Court/Lisa Baderoon/Rebecca Skye Dietrich
Buchanan Communications +44 (0)20 7466 5000
The Trout Group +1 212 477 9007
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
PSA and PSA responses
PSA is a protein, prostate-specific antigen. Levels of PSA in the
blood are used in the diagnosis of prostate cancer and the tracking
of responses to its treatment. PSA is one of the most widely
recognised disease markers in oncology.
PSA response was defined as a 50% or greater reduction in PSA level
from baseline. This is in accordance with the Bubley criteria
(Eligibility and response guidelines for phase II clinical trials in
androgen-independent prostate cancer: recommendations from the
Prostate-Specific Antigen Working Group. Journal of Clinical Oncology
1999, Volume 17, pp 3461-3467).
Tumour responses (reflecting the growth or shrinkage or tumours after
treatment) were assessed according to RECIST (Response Evaluation
Criteria In Solid Tumours). In prostate cancer, modified RECIST
criteria are used because of the need to assess bone metastases,
which cannot be assessed using the standard criteria. RECIST response
rate was determined by an independent, blinded assessor who analysed
all the scans from the study.
Time to disease progression
Time to disease progression was determined by the trial
investigators; this was based on PSA findings, modified RECIST data
and relevant clinical observations.
Background on ASA404
ASA404 (DMXAA) is a small-molecule vascular disrupting agent which
targets the blood vessels that nourish tumours. The drug was
discovered by Professors Bruce Baguley and William Denny and their
teams at the Auckland Cancer Society Research Centre, University of
Auckland, New Zealand. It was in-licensed by Antisoma from Cancer
Research Ventures Limited (now Cancer Research Technology), the
development and commercialisation company of the Cancer Research
Campaign (now Cancer Research UK), in August 2001. CRUK had supported
two phase I studies in the UK and New Zealand. ASA404 has shown a
substantial survival benefit in patients with non-small cell lung
cancer when added to paclitaxel-based chemotherapy in a randomised
phase II study. Worldwide rights to the drug were licensed to
Novartis AG in April 2007.
Background on Antisoma
Based in London, UK, Antisoma is a biopharmaceutical company that
develops novel products for the treatment of cancer. Antisoma 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. Please visit
www.antisoma.com for further information.
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