Antisoma’s AS1411 granted EU Orphan Drug Status for renal and pancreatic cancers

London, UK: 22 February 2006 Cancer drug developer Antisoma plc (LSE: ASM, US OTC: ATSMY) today announces that its aptamer drug AS1411 has been granted Orphan Drug Status in the European Union for the treatment of renal and pancreatic cancers. This will provide a ten-year period of market exclusivity if AS1411 is approved as a treatment for either disease. The drug already has US Orphan Drug Status for both renal and pancreatic cancers.

AS1411 has shown promise in patients with renal cancer: of three who participated in a phase I trial, two showed long-term stable disease and one a near-complete response. An extension of this trial is recruiting additional renal cancer patients and will yield new data during 2006. Antisoma expects renal cancer to be an important indication for later-stage trials: the Company will seek to conduct an accelerated clinical development programme.

Pancreatic cancer is one of a number of other cancers in which there are supportive preclinical data for AS1411. These include both solid and blood cancers. Antisoma is working to identify which indications should receive the highest priority for entry into phase II trials. Conventional phase II studies in other cancers would likely run in parallel with any expedited programme in renal cancer.

Antisoma’s Chief Executive Officer, Glyn Edwards, said: “Receipt of EU orphan drug status for both renal and pancreatic cancers supports our view that AS1411 has potential against a variety of cancers. The drug’s early promise in renal cancer has opened up the possibility of rapid progress towards the market in this indication, so we are particularly pleased that we now have orphan status for renal cancer on both sides of the Atlantic.”

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.


Notes to Editors

AS1411
Aptamers are short pieces of DNA or RNA that can fold into stable, three-dimensional structures capable of interacting with particular target proteins. AS1411 is the first aptamer to be tested as a treatment for cancer. It binds to the protein nucleolin, which is found on the surface of cancer cells. It is then internalised and has been shown to kill cancer cells in a range of models. The drug has also shown anti-cancer effects in animal models and promising signs of anti-cancer activity in a phase I study conducted at the Brown Cancer Center, Louisville, Kentucky. AS1411 was originally developed by Dr Paula Bates, Dr John Trent and Prof. Donald Miller at the University of Alabama and then at the University of Louisville. Antisoma added AS1411 to its pipeline when it acquired the Louisville-based company Aptamera Inc. in February 2005.

Orphan Drug Status
The orphan drug programme of the European Medicines Agency (EMEA) is designed to promote the development of drugs to treat rare life-threatening or very serious conditions that affect no more than five in every 10,000 people in the European Union. The designation provides EU market exclusivity for up to ten years in the given indication. Other potential benefits include: a reduction in fees associated with various aspects of the regulatory process, including the application for marketing approval, and EMEA guidance in preparing a dossier for marketing approval.

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.

Contact Information

Glyn Edwards

Chief Executive Officer

Antisoma plc

Contact via E-mail