LONDON, May 16, 2005 (PRIMEZONE) -- American Society of Clinical Oncology Meeting, Orlando, Fla., -- Cancer drug developer Antisoma (LSE:ASM) announces the presentation at ASCO of positive phase I data underpinning the progress of its vascular disrupting agent AS1404 (DMXAA) into phase II trials. The data from the 'DART' study show a clear 'therapeutic window', identifying a dose of AS1404 that was well-tolerated but nevertheless produced near-maximal effects on tumour blood vessels, as indicated by the chemical marker 5HIAA. This dose is being used in an extensive phase II programme, including a US and Australian prostate cancer study in which the first patient has now been treated. A trial in non-small cell lung cancer is ongoing and a trial in ovarian cancer will start shortly, both involving hospitals across Europe, Australia and New Zealand.
AS1404 is described as a 'vascular disrupting agent' because it attacks established tumour blood vessels. All solid tumours rely on a blood supply to survive and grow, so the drug has broad therapeutic and market potential. Preclinical data show that vascular disrupting agents are most effective when combined with other treatments such as chemotherapies. The generally favourable tolerability profile of AS1404, reaffirmed by the data presented at ASCO, has been critical in allowing the drug to be combined with chemotherapy drugs in phase II studies. More specifically, the new phase I data show that cardiovascular effects are not of concern at the chosen dose of AS1404.
Dr Mark McKeage of the University of Auckland, New Zealand, an investigator in both the reported phase I trial and the ongoing phase II lung cancer study, presented the findings. Speaking before the presentation Dr McKeage said: "We've gained considerable experience with AS1404 in New Zealand, and are excited by its potential. No drug in use today specifically targets established tumour blood vessels, and a drug with this action and suitable for combination with existing treatments would be a valuable addition."
Antisoma's CEO Glyn Edwards said: "Vascular disruption is a novel approach to cancer therapy with substantial market potential. Our ASCO presentation underlines the competitive strengths of AS1404 within the class of vascular disrupting agents and the strong platform on which our progress into phase II trials was based. Those trials are advancing rapidly, with treatment of patients now underway in our prostate cancer study and first efficacy results expected from our lung cancer study later this year."
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Glyn Edwards, CEO
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 (DMXAA) is a small-molecule vascular disrupting agent. 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 Technologies) in August 2001.
Phase I DART Study of AS1404
The DART (DMXAA in Refractory Tumours) trial was conducted in New Zealand. It included 15 patients with a variety of tumours refractory to standard treatments. This was the third phase I monotherapy trial of AS1404; two previous studies supported by the Cancer Research Campaign (now CRUK) have been reported and published.
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. 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.