LONDON and PARIS, Nov. 1, 2005 (PRIMEZONE) -- Cancer drug developer Antisoma (LSE:ASM) will today present data on its most advanced drug, AS1404, at ECCO -- the European Cancer Conference. AS1404 works by damaging the blood vessels that sustain tumours. New tests have examined this effect by measuring the leakage of a dye from the bloodstream into tissues. Treatment with AS1404 increased leakage into tumour tissue but not into normal skin. This finding provides new and direct evidence that AS1404 selectively disrupts tumour blood vessels whilst leaving those in healthy tissues unharmed.
Leakage of blood from tumour vessels correlated clearly with levels of a blood chemical, 5HIAA, supporting the value of this chemical as a marker of damage to tumour blood vessels. Dose-response findings from phase I patients show that the optimal biological dose of AS1404 to cause changes in the level of 5HIAA is in the range of 1200mg/m2, the dose now being used in phase II combination studies.
Today's presentation follows Antisoma's recent announcement of promising preliminary findings from a phase II trial of AS1404 in non-small cell lung cancer. Patients receiving AS1404 in addition to chemotherapy have shown a higher frequency of tumour responses and a lower frequency of progressive disease than patients receiving chemotherapy alone.
Antisoma's Chief Operating Officer, Dr. Ursula Ney, said: "The data presented today are consistent with the encouraging findings to date from our phase II lung cancer study of AS1404. Antisoma is now firmly established as a leader in the vascular disruption field."
Disclaimer
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.
Background on AS1404
AS1404 (chemical name DMXAA) is a small-molecule derived from xanthenone acetic acid. A member of the class of drugs known as 'vascular disrupting agents', it is the only representative of its subclass in clinical trials and is the first of these drugs to report efficacy data from a controlled study (for full details see announcement of October 17th 2005). AS1404 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 Technologies) in August 2001.
5HIAA
5HIAA (5-hydroxyindoleacetic acid) is a metabolite of serotonin (5HT), a naturally occurring vasoactive substance which is released from platelets into the bloodstream under various pathological conditions. Disruption of tumour blood vessels by AS1404 is associated with an increase in blood serotonin levels. However, because serotonin is unstable in samples when they are stored it is not suitable for routine clinical assay. Its metabolite 5HIAA is more stable and can therefore be used as a measure of serotonin release. An assay for 5HIAA in plasma has been developed by scientists at the Auckland Cancer Centre in New Zealand.
Background on Antisoma
Based in London, U.K., 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. In 2002, Antisoma formed a broad strategic alliance with Roche to develop and commercialise products from Antisoma's pipeline. AS1404 is included within the Roche alliance. Please visit www.antisoma.com for further information about Antisoma.