Algeta’s Phase II clinical study of Alpharadin™ highlights its potential as a treatment for bone metastases in prostate cancer patients

– meets primary endpoint in bone marker analysis
Analysis presented at 2006 Prostate Cancer Symposium

Oslo, Norway, February 27, 2006 – Algeta ASA, a therapeutics company dedicated to the development of novel anticancer agents based on alpha particle emitting radionuclides, is pleased to announce that an analysis of the biomarker data from a Phase II trial of its lead product Alpharadin™ (radium-223) continues to demonstrate its potential as a treatment for bone metastases in hormone-refractory prostate cancer (HRPC) patients. Data from this trial (BC1-02) were presented yesterday in a poster (Ref.1) at the 2006 Prostate Cancer Symposium in San Francisco, CA.

Algeta is conducting trial BC1-02 as part of its Phase II clinical program for Alpharadin™, a novel radiopharmaceutical based on the alpha particle emitter radium-223, which naturally targets and attacks skeletal metastases. The double-blind placebo-controlled trial involves 64 patients with painful skeletal metastases as a consequence of HRPC and is in its follow-up phase at 11 centers in Norway, Sweden and the UK. The trial was fully enrolled in May 2005.

The trial results presented are based on four-month follow-up data. Alpharadin™ treatment met the primary endpoint of the trial. There was a highly statistically significant decrease of bone-alkaline phosphatase (bone-ALP) compared to placebo (ITT: p<0.001). Strong demonstration of Alpharadin’s effect on other markers of bone turnover, S-PINP (bone formation) and S-CTX-I and S-ICTP (bone resorption), were also observed.

Interesting PSA (prostate specific antigen) results were demonstrated with a significantly better PSA response in patients given Alpharadin™ compared to placebo. Together, these data show that Alpharadin™ treatment a clear effect on the microenvironment of bone metastases indicative of a positive therapeutic effect.

Clinical endpoints such as delay of disease progression, long-term safety, survival, as well as further biomarker data will be analyzed at 12 months, and results of this analysis are due during the second half of 2006.

This study, in addition to the earlier Phase I trials (Ref.2), demonstrates that repeated doses of Alpharadin™ result in minimal bone marrow suppression. Algeta has two further pain palliation and therapeutic dose-finding Phase II trials ongoing during 2006.

Professor Sten Nilsson, Head of the Urologic Oncology Group at the Karolinska Hospital and Institute in Stockholm and Principal Investigator of the trial, commented: “These results are very encouraging. While only biomarker data have been analyzed at this stage, the indication is that Alpharadin™ is having a therapeutic effect on bone metastases. We will evaluate clinical outcomes in patients at the 12-month follow-up stage, but evidence is mounting to suggest that this targeted approach to treating bone metastases has great potential.”

“We are very pleased with the initial analysis of this study,” said Dr Thomas Ramdahl, CEO of Algeta. “The significant decrease both in levels of prognostic bone markers and in PSA demonstrates the potential of radium-223 in the treatment of patients with skeletal metastases, which is a common and catastrophic development of many cancers, particularly prostate and breast cancer.”

Further details of the BC1-02 Alpharadin™ Phase II clinical trial

HRPC patients participating in the trial initially received palliative external beam radiotherapy before being randomized to receive four intravenous injections of Alpharadin™ (50 kBq per kg body weight) or saline, repeated at four-week intervals. Levels of bone-ALP (bone-alkaline phosphatase, primary endpoint), S-PINP (serum procollagen I N propeptide), S-CTX-I (serum C-terminal crosslinking telopeptide of type I collagen), S-ICTP (serum type I collagen cross-linked C- telopeptide) and PSA (prostate specific antigen) were analysed (Alpharadin™ versus saline) following the four-month visit.

33 patients received Alpharadin™ and 31 patients received saline. Active treatment resulted in a statistically significant decrease in bone-ALP from baseline compared to placebo. The mean (± SD) change from baseline to four weeks after last injection for Alpharadin™ (33 patients) was -58% ± 37 versus +47% ± 107 in the placebo group (29 patients), p<0.001. A similar pattern was seen for S-PINP. Statistically significant changes in the bone resorption parameters S-CTX-I and S-ICTP in favor of the active drug compared to placebo were also observed. In the Alpharadin™ group, 15 of 31 patients (48 %) showed PSA response of ?50% decrease from baseline, compared to only 5 of 28 patients (18 %) in the placebo group. Minimal bone marrow suppression during the treatment period was also shown.

References

1. Nilsson, S. et al. Bone-seeking radium-223 adjuvant to external beam radiotherapy demonstrates significant decline in bone-alkaline phosphatase and PSA in patients with hormone refractory prostate cancer (HRPC). Poster presentation at the 2006 Prostate Cancer Symposium, San Francisco, CA, 24-26 February 2006.

A copy of the poster can be obtained at here: www.algeta.no/admin/files/Algeta%202006%20Prostate%20Cancer%20Symposium.pdf

2. Nilsson S., et al., Clin Cancer Res. 2005;11 (12): 4451-4459

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Notes to Editors

About Algeta ASA

Algeta ASA, headquartered in Oslo, Norway, is a private therapeutics company dedicated to the development of novel anticancer therapeutics based on alpha particle emitting radionuclides. The Company was founded in 1997 as Anticancer Therapeutic Inventions AS.

Algeta’s lead product candidate, Alpharadin, is a novel bone-seeking experimental radiopharmaceutical based on the alpha particle emitter radium-223. Alpharadin is currently in Phase II clinical trials as a potential new treatment for bone metastases from prostate cancer.

An estimated 1.5 million patients worldwide suffer with bone metastases and there are approximately 300,000 new cases per year. Prostate and breast cancers account for more than 80% of all cases. Median survival for patients is three years and there are no effective therapies.

Alpha emitters have not until recently been a significant therapeutic modality. However, discoveries in radiochemistry and recent advances in the understanding of tumor and radiation biology led Algeta’s scientific founders – Roy Larsen and Øyvind Bruland – to conceive how the unique features of alpha emitters, such as high potency and short range, could be exploited to create new therapeutic candidates promising unrivalled potency without unacceptable toxicities.

For more information, visit us at www.algeta.com

Contact Information

Dr Thomas Ramdahl

CEO

Algeta ASA

Contact via E-mail