Silence Therapeutics and Intradigm merge to form RNAi

The Boards of Silence Therapeutics plc (AIM: SLN) and Intradigm Corporation are delighted to announce the merger of their businesses to form a leading company in the field of RNAi (RNA interference). The enlarged company, to be called Silence Therapeutics, will have multiple RNAi discovery, development and delivery technologies, a broad internal and partnered product pipeline and a broad portfolio of intellectual property.

The Directors believe the merger will enable Silence Therapeutics to build a competitive offering and facilitate more deals of greater value with the pharmaceutical industry. In particular, the combined business will be able to offer potential partners a choice of technologies to deliver RNAi molecules to diseased tissue, one of the main challenges in the emerging field of RNAi therapeutics. In addition, the enlarged Silence Therapeutics will have the financial strength to exploit its technology by developing its own therapeutic candidates.

Silence Therapeutics will issue 79,640,668 of its Ordinary Shares to acquire the entire share capital of Intradigm. Upon completion of the transaction, Intradigm's shareholders and management will own 36.6 percent of the enlarged group. The completion of the proposed acquisition is contingent upon approval by Silence Therapeutics' shareholders.

In parallel with the merger, Silence Therapeutics has raised 15 million pounds Sterling through a placing and subscription of shares at a price of 23 pence per share. Existing shareholders of Intradigm, including Alta Partners, Frazier Healthcare, Lilly Ventures, Roche Finance and Astellas Venture have committed over 5 million pounds of new funds by way of subscription. The placing has been underwritten by Nomura Code Securities Limited, who also advised Silence Therapeutics on the merger with Intradigm.

Iain Ross, currently chairman of Silence Therapeutics, will remain as Chairman of the enlarged company. Philip Haworth, Chief Executive of Intradigm, will become CEO of Silence Therapeutics and Klaus Giese will continue as Chief Scientific Officer of Silence Therapeutics.

The transaction will bring five strategic benefits:

• A broad platform of technologies capable of addressing the discovery, development and delivery of RNAi therapeutics. The combined companies' capabilities extend to all essential areas for short interfering RNA (siRNA) product development and in particular delivery, but also structure, chemistry and a diverse library of therapeutic siRNA sequences.
• An advancing pipeline of internal and partnered product candidates. Four of the nine siRNA candidates currently in clinical development globally utilize Silence's technology.
• A broad intellectual property portfolio, with protection covering all essential areas of RNAi therapeutic development, including target sequences, delivery and siRNA structural features.
• An expanded scientific team and an experienced group of senior executives and board of directors.
• Expanded financial support and stability to facilitate new growth opportunities. International shareholder base offers broader access to capital to enable internal growth and provide additional strength for the purpose of negotiating favorable strategic transactions in the sector.

Iain Ross, Chairman of Silence Therapeutics, said: "By bringing together a comprehensive platform of siRNA delivery and development technologies, we believe Silence Therapeutics will be a partner of choice for those seeking to develop RNAi therapeutics. With a strengthened balance sheet, experienced management and extended research capability, Silence Therapeutics is well placed to strike the development deals that will deliver value for shareholders."

Philip Haworth, Chief Executive of Intradigm, said: "We are excited to join forces with Silence Therapeutics and look forward to continuing our pursuit of valuable RNAi therapeutics as part of this new team. Perhaps most exciting about the merger is the powerful range of RNAi delivery technology solutions possessed by the new company. The most significant hurdle to be overcome in realizing the vast potential of RNAi therapeutics is that of enabling safe and effective delivery of siRNA payloads. By combining the impressive expertise of both Intradigm and Silence, we now have one of the industry's most comprehensive and versatile delivery technology platforms, providing the enlarged company with an unparalleled potential to develop delivery solutions that can be tailored to address various therapeutic requirements."

The board of the enlarged company will have eight members. Five of the nominated directors currently sit on the Board of Silence Therapeutics: Iain Ross, Jerry Randall, Annette Clancy, David U'Prichard and Melvyn Davies. The remaining three Board members are directors of Intradigm: James Topper, David Mack and Philip Haworth.

Documentation describing the transaction and share placing will be posted to Shareholders later today. More information about the proposed acquisition is also available from Silence Therapeutics and from the company website: www.silence-therapeutics.com.

An Extraordinary General Meeting of shareholders to approve the transaction and share placing will be held on January 4, 2010 at 10:00am.

The suspension of trading in Silence Therapeutics shares is expected to be lifted later today.