Conference presentations highlight leading position of Antisoma’s AS1404

6 February 2006, La Jolla, California, and London, UK: 6 February 2006 Cancer drug developer Antisoma (LSE:ASM; US OTC:ATSMY) announces the presentation of data on its vascular disrupting agent, AS1404, at the 8th International Symposium on Anti-Angiogenic Agents in La Jolla, California.

On Saturday, Professor Gordon Rustin, Director of Medical Oncology at Mount Vernon Hospital, Northwood, UK, gave a plenary lecture entitled ‘Current State of the Clinical Development of Vascular Disrupting Agents’, which highlighted the progress made in developing AS1404. Three randomised controlled phase II trials are ongoing in lung, prostate and ovarian cancers, each asking whether addition of AS1404 to a taxane-based regimen provides extra benefit to patients.

The strong preclinical data supporting these three trials was showcased in a poster presented by Antisoma’s Head of Research, Professor Lloyd Kelland. In animal models of lung, prostate and ovarian cancers addition of AS1404 to the appropriate taxane provided clear additional benefit compared with the taxane alone. Some cures were seen among animals treated with AS1404-taxane combinations but not in any of those receiving a taxane alone.

Antisoma expects to report key data on time to tumour progression from the phase II lung cancer study during the first half of this year. The Company also expects to report findings from the trials in prostate and ovarian cancers during 2006.

Antisoma’s CEO, Glyn Edwards, said: “Professor Rustin’s talk highlights the potential of vascular disrupting agents as a distinctive new approach to attacking tumours via their blood supply. In reporting encouraging preliminary findings from our phase II study of AS1404 in lung cancer late last year, we became the first company with data from a randomised study of a vascular disrupting agent, and are now clearly established as a leading player in this field.”

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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 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 Technologies) in August 2001. Preclinical evidence shows that the drug significantly enhances the efficacy of various chemotherapy drugs, complementing their action on tumours. Antisoma’s programme of phase II trials therefore combines AS1404 with established chemotherapy treatments. The programme includes separate randomised, controlled trials in lung, prostate and ovarian cancers.

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.

Contact Information

Margherita Lupi

Communications Manager

Antisoma

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