Oslo, Norway, 5 May 2011 - Algeta ASA (OSE: ALGETA), a company focused on the development of novel targeted cancer therapeutics, announces that it has entered into an exclusive research, development and commercialization agreement with Affibody (Stockholm, Sweden) to develop tumor-targeting alpha-pharmaceuticals based on thorium-227.

Under the terms of the agreement, Algeta gains access to two proprietary Affibody® molecules for use in cancer therapy. These molecules are able to bind to two validated tumor targets: HER-2, which is present on aggressive breast tumors, and PDGFRβ[<03B2>][<03B2>], which plays a significant role in angiogenesis associated with solid tumor growth and development. Affibody® molecules are a novel class of small targeting molecules with antibody-like properties that have the potential to be excellent carriers of therapeutic payloads and may in addition have efficacy, safety and pharmacokinetic benefits.

Algeta and Affibody will collaborate on a defined technical program to determine whether the two Affibody® molecules covered by this agreement can be effective carrier targeting molecules for Algeta's thorium-227 payload.
Algeta will pay a signing fee to Affibody and make further payments based upon the achievement of certain milestones and commercial success. Algeta has an exclusive worldwide license for both HER-2 and PDGFRβ[<03B2>][<03B2>] in its chosen field. If the initial research collaboration is successful, Algeta will be responsible for all preclinical and clinical development of any development candidates that result from this collaboration, and commercialization.

As part of the collaboration, Algeta also gains access to Affibody's proprietary Albumod™ platform applied to the two Affibody® targeting molecules. This is designed to enhance their efficacy by extending their circulatory half-life.

Thomas Ramdahl, Executive Vice President and Chief Technology Officer, said: "Affibody has unique antigen-binding molecules that could be well suited to creating tumor targeted alpha-pharmaceuticals with thorium-227. We have already obtained interesting results using conventional antibodies and are now looking to broaden the potential utility of our thorium platform by combining our thorium-227 technology with Affibody's carrier molecules."

About the Thorium platform

Thorium-227 is an element (radionuclide) that emits high-energy alpha particles. Such elements are of considerable interest in the treatment of cancer as they are potent at killing tumor cells and have a highly localized effect as a result of the very short range of the alpha particle (2-10 cell diameters).

Current top-selling cancer drugs are based on 'naked' monoclonal antibodies, but it is clear that next-generation products will require cancer-killing payloads to maximize the effectiveness of therapy. Thorium-227 is linked to tumor-targeting molecules, such as monoclonal antibodies, to reach its target. By conjugating thorium-227 to a number of such molecules, each with a different tumor target, Algeta is exploring the potential to create a pipeline of new-generation alpha-pharmaceuticals that specifically seek and destroy cancers while minimizing damage to surrounding healthy tissues.

Importantly, the direct tumor cell killing action of alpha-pharmaceuticals potentially overcomes drug-resistance mechanisms. In addition, they cause a localized 'bystander effect', whereby tumor cells adjacent to those bound by the alpha-pharmaceutical may also be destroyed even if they do not bind the drug themselves. The short range of the alpha particle means that damage to healthy cells and side effects may be minimized.

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