Antisoma appoints Dr Gary Acton as Chief Medical Officer

London, UK: 24 April 2006 Cancer drug developer Antisoma plc (LSE: ASM, US OTC: ATSMY) today announces the appointment of Dr Gary Acton as Chief Medical Officer.

Dr Acton, 47, joins Antisoma with 19 years’ experience in the pharmaceutical and biotechnology industries. Most recently he has run an oncology orientated consultancy service, assisting a number of biopharmaceutical companies in the progression and optimisation of their development portfolios. From 2000 to 2002 he was European Managing Director of Cell Therapeutics, Inc, where he led the successful application for European marketing approval of the cancer drug Trisenox. Prior to this, Dr Acton spent five years as Vice President of Clinical Development at Vernalis, where he was also a main board member. He was responsible for development of the Company’s entire portfolio, including the US and European approvals of frovatriptan, a drug now marketed in all major territories. This followed five years as UK Director of Clinical Research for Fujisawa and a period at SmithKline and French.

Dr Acton holds medical qualifications from the Universities of Oxford and London and a Diploma of Pharmaceutical Medicine. He is also a Fellow of the Faculty of Pharmaceutical Physicians.

Glyn Edwards, Chief Executive Officer, commented “Gary brings invaluable clinical development experience to Antisoma as we continue to progress and expand our portfolio of cancer drugs, and I am delighted to welcome him to our team.”

For further information about Antisoma please visit the Company’s website at www.antisoma.com

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 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. Please visit www.antisoma.com for further information about Antisoma.

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Mark Court

Buchanan Communications for

Antisoma plc

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