Algeta demonstrates potential of alpha-emitter platform to generate new antibody therapeutics targeting breast cancer and lymphoma

Oslo, Norway - Algeta ASA (OSE: ALGETA), the cancer therapeutics company, announces that a series of scientific papers demonstrating the targeted and localized anticancer potential of the alpha-emitter thorium-227 (227Th) linked to trastuzumab (Herceptin) and to rituximab (Rituxan) will be presented at the forthcoming 56th annual Society for Nuclear Medicine 2009 meeting (Toronto, Canada; 13-17 June).

These antibodies target tumors expressing the cell surface proteins HER-2 and CD20, which are present on certain breast cancer and lymphoma cells, respectively.

This is the first time that the targeted cancer cell-killing effect of 227Th-trastuzumab will be presented and suggests that further studies be conducted with this alpha-pharmaceutical as a novel treatment for breast cancer. Trastuzumab targets tumor cells presenting the HER-2 receptor, and tumors in approximately 25% of breast cancer patients carry this marker.

Other presentations at the meeting will provide further evidence of the targeted therapeutic effect and safety of 227Th-rituximab as a new alpha-pharmaceutical for treating non-Hodgkin’s lymphoma. Algeta and its academic collaborators have previously published data on the potential of 227Th-rituximab to target and kill lymphoma cells in the leading medical journal Blood (Dahle, J. et al. 2007). The new presented findings support the clinical development of this novel alpha-pharmaceutical in this indication.

The exciting findings from early studies linking thorium-227 to these highly validated and specifically targeted antibodies will be presented by scientists from the Norwegian Radium Hospital and other leading Norwegian research institutes, who generated the data in collaboration with Algeta.

Thorium-227, like radium-223 - which forms the basis of Alpharadin, Algeta’s lead product in phase III development for treating bone metastases in patients with advanced prostate cancer - 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 but have a highly localized effect. By linking thorium-227 to tumor-targeting molecules such as monoclonal antibodies, Algeta has the potential to create a pipeline of new generation alpha-pharmaceuticals with the potential to specifically seek and destroy cancers while minimizing damage to surrounding healthy tissues.

Thomas Ramdahl, EVP and Chief Technology Officer at Algeta, said, “The studies that will be presented by our academic collaborators at the SNM meeting further highlight the exciting potential of our alpha-emitter technology platform to generate new targeted and effective cancer therapeutics. The success of monoclonal antibodies in targeting specific tumor cells provides a significant opportunity to build a unique pipeline of novel alpha-pharmaceuticals.”

Details of presentations at SNM 2009

The following oral presentations will be given by Dr. Jostein Dahle (Norwegian Radium Hospital) and will take place in the:
Radiochemistry/Development Studies Session
Sunday 14 June
4.15 - 4.39pm
Room 701B

# Assessment of long-term radiotoxicity after treatment with the low dose-rate alpha-particle emitting radioimmunoconjugate 227Th-rituximab

# Targeted therapy of breast cancer with low dose-rate alpha-particle-emitting 227Th-trastuzumab

The following posters will be presented in the:
Meet the Authors Posters Session IV: Radiopharmaceutical Chemistry Track Posters
Tuesday 16 June
5.15 - 6.00pm
Exhibit Hall E/F

# In vitro cytotoxicity of low dose-rate radioimmunotherapy by the a-emitting radioimmunoconjugate 227Th-rituximab
# Treatment of HER2-expressing breast cancer and ovarian cancer cells in vitro with low dose rate alpha-particle-emitting 227Th-trastuzumab

# Treatment of mice with SKBR-3 breast cancer or SKOV-3 ovarian cancer xenografts with low dose rate alpha-particle-emitting 227Th-trastuzumab

# An improved labeling method for thorium-227 labeled antibodies for targeted alpha therapy

About Algeta
Algeta ASA is a cancer therapeutics company built on world-leading, proprietary technology. Algeta is developing a new generation of targeted cancer therapeutics (alpha-pharmaceuticals) that harness the unique characteristics of alpha particle emitters and are potent, well-tolerated and convenient to use.

Algeta’s lead alpha-pharmaceutical candidate, Alpharadin (based on radium-223), has blockbuster potential for treating bone metastases arising from multiple major cancer types, owing to its bone-targeting nature, potent efficacy (therapeutic and palliative) and benign, placebo-like safety profile. Development of Alpharadin is most advanced targeting bone metastases resulting from hormone-refractory prostate cancer (HRPC), and it entered an international phase III clinical trial (ALSYMPCA) in mid-2008 based on compelling clinical results from a comprehensive phase II program.

Algeta’s strategy is to launch Alpharadin as a first or second line treatment for cancer patients with bone metastases either alone or in combination with current standard of care therapies, thereby maximizing its commercial potential.

Algeta is also developing other technologies for delivering alpha-pharmaceuticals. These include microparticles, liposomes, and methods to enhance the potency of therapeutic antibodies and other tumor-targeting molecules by linking them to the alpha particle emitter thorium-227. The Company is headquartered in Oslo, Norway, and was founded in 1997.

Algeta listed on the Oslo Stock Exchange in March 2007 (Ticker: ALGETA).

Alpharadin and Algeta are trademarks of Algeta ASA.

Forward-looking Statement
This news release contains forward-looking statements and forecasts based on uncertainty, since they relate to events and depend on circumstances that will occur in the future and which, by their nature, will have an impact on results of operations and the financial condition of Algeta. There are a number of factors that could cause actual results and developments to differ materially from those expressed or implied by these forward-looking statements. Theses factors include, among other things, risks associated with technological development, the risk that research & development will not yield new products that achieve commercial success, the impact of competition, the ability to close viable and profitable business deals, the risk of non-approval of patents not yet granted and difficulties of obtaining relevant governmental approvals for new products.