Antisoma PLC's Acquisition of Xanthus Pharmaceuticals, Inc. Approved by Shareholders

Antisoma plc (LSE:ASM; USOTC:ATSMY) announces that the resolutions put to today's Extraordinary General Meeting (EGM) of Antisoma's shareholders were passed with the support of over 89% of votes cast. These included a resolution to acquire Xanthus Pharmaceuticals Inc., and, by association, the fundraising linked with the acquisition. Full details of the proxy voting are available on Antisoma's website at www.antisoma.com

Copies of the resolutions passed at the EGM today are available for inspection at the UK Listing Authority's Document Viewing Facility, which is situated at:

The Financial Services Authority
25 The North Colonnade
Canary Wharf
London E14 5HS
Tel: +44 (0) 20 7066 1000

A further announcement will be made regarding admission of the shares issued in connection with the acquisition and fundraising and the completion of the transaction.

Enquiries:

Antisoma plc Tel: +44 (0)7909 915 068
Glyn Edwards, Chief Executive Officer
Daniel Elger, Director of Communications

Buchanan Communications Tel: +44 (0)20 7466 5000
Mark Court/Lisa Baderoon/Rebecca Skye Dietrich

Piper Jaffray Ltd Tel: +44 (0)20 3142 8700
Neil Mackison
Rupert Winckler

Background to the acquisition and fundraising
On 16 May, Antisoma announced that it had entered into an agreement to acquire private US oncology company Xanthus Pharmaceuticals, Inc. in an all-share deal valued at GBP 26.8 million (USD 52.2 million) and that it had simultaneously executed a fundraising providing, before expenses, an additional GBP 20.9 million to the Enlarged Group. Further details are available in the press release of 16 May.

Notes and disclaimers
Piper Jaffray, which is authorised and regulated in the UK by the Financial Services Authority, is acting as financial adviser and broker to Antisoma in connection with the proposals and no-one else and will not be responsible to anyone other than Antisoma for providing the protections afforded to clients of Piper Jaffray nor for providing advice in relation to the proposals nor any other matter referred to in this announcement.

Words and expressions used in this announcement will have the same meaning as defined in the prospectus and circular that has been sent to shareholders.

This document does not constitute an offer or invitation to purchase or subscribe for any securities of Antisoma and no part of it shall form the basis of or be relied upon in connection with any contract or commitment whatsoever.

The information contained herein is not for publication, distribution or release in or into the United States. The material set forth herein is for informational purposes only and is not intended, and should not be construed, as an offer of securities for sale in the United States. The securities described herein have not been and will not be registered under the U.S. Securities Act of 1933, as amended (the "Securities Act"), or the laws of any state or other jurisdiction, and may not be offered or sold within the United States, except pursuant to an exemption from, or in a transaction not subject to, the registration requirements of the Securities Act and applicable laws of any state or other jurisdiction. There is no intention to register any portion of the securities described herein in the United States.

This document is not an offer to sell or the solicitation of an offer to buy any securities in any jurisdiction where such offer or sale is not permitted.

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 or licensing activities, including statements regarding the clinical development programmes, the expected timing of clinical trials and regulatory filings, out-licensing opportunities, and funding requirements. Such statements are based on management's current expectations, but actual results may differ materially.