ATTRACT-1 phase III trial of ASA404 halted following interim analysis

ATTRACT-1 phase III trial of ASA404 halted following interim analysis

29 March 2010, London, UK, and Cambridge, MA: Antisoma plc (LSE: ASM; USOTC: ATSMY) announces that the planned interim analysis of data from the ATTRACT-1 phase III trial of ASA404 in previously untreated non-small cell lung cancer (NSCLC) has shown that continuation of the trial would be futile, as there is little or no prospect of demonstrating a survival benefit with ASA404 in this setting. The ATTRACT-1 trial will therefore be halted.

No new or unexpected serious adverse effects of ASA404 have been identified by the trial's Data Monitoring Committee.

Glyn Edwards, CEO of Antisoma, said: "We are disappointed by the outcome of the ATTRACT-1 study, especially given the very encouraging phase II data reported in the same setting. We had hoped that this trial would show that use of ASA404 could improve treatment for patients with newly diagnosed lung cancer. We are now focused on delivering phase III results for our other late-stage product, AS1413."

Antisoma had unaudited cash and short-term investments of GBP 45.1 million at the end of February 2010.

A conference call will be held today at 9 am UK time. This will be available afterwards as a recording on the Antisoma website at A further conference call will be held at 2 pm UK time/9 am Eastern time. Dial-in numbers for the calls are as follows: + 44 (0)20 3364 5947; UK Toll Free: 0808 238 7396; US Toll Free: 1866 793 4273; participant pin code: 468563#

Glyn Edwards, CEO  
Daniel Elger, VP Marketing & Communications +44 (0)7909 915 068
Antisoma plc  
Mark Court/Lisa Baderoon/Catherine Breen  +44 (0)20 7466 5000
Buchanan Communications  
Seth Lewis +1 617 583 1308
The Trout Group  

Except for the historical information presented, certain matters discussed in this announcement 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.

About the ATTRACT-1 study in NSCLC
ATTRACT-1 was a pivotal study of ASA404 in previously untreated, advanced NSCLC. Patients were randomised 1:1 to receive either ASA404 plus chemotherapy (carboplatin/paclitaxel) or a placebo plus chemotherapy (carboplatin/paclitaxel) as a control.

About ASA404
ASA404 (vadimezan, formerly known as DMXAA and AS1404) is a small-molecule Tumour-Vascular Disrupting Agent (Tumour-VDA) 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 Technology), the development and commercialisation company of the Cancer Research Campaign (now Cancer Research UK), in 2001. Worldwide rights to the drug were licensed to Novartis AG in April 2007.

About Antisoma
Antisoma is a London Stock Exchange-listed biopharmaceutical company that develops novel products for the treatment of cancer. In addition to ASA404, the Company's drugs in development include AS1413, being tested in a phase III trial as a treatment for secondary acute myeloid leukaemia (AML), AS1411, being tested in a phase IIb trial in AML, and a pre-clinical programme of Dendritic Cell Autoimmune Modulators (DCAMs), being developed for auto-immune indications. The Company has operations in the UK and the US. Please visit for further information about Antisoma.

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