At the annual American Society of Clinical Oncology (ASCO) meeting in Chicago in June 2011, the Prostate Cancer Foundation September 30th newsletter reported on promising Phase III clinical trial results for radium-223 chloride (alpharadin), an agent specifically being developed for cancer patients with bone metastases. The drug works by emitting small doses of alpha particle radiation that damage the DNA of cancer cells, thereby killing them without harming healthy cells. [It should be noted that in comparison with other radioactive particles, alpha particles are quite heavy and do not penetrate surrounding tissues very far.] The data presented indicated that alpharadin significantly improves overall survival in patients with hormone-resistant prostate cancer that has metastasized to the bone. This conclusion was also cited in a report in the October 4th ZeroHour Newsletter. Thus, alpharadin may be the first drug to improve survival in men with cancer of the prostate that has spread to the bone, a worsening of the disease that occurs in 90 percent of men in the advanced stages of the disease.
Alpharadin was initially discovered by a Norwegian company Algeta ASA and was subsequently exclusively licensed to Bayer HealthCare Pharmaceuticals. On the basis of the results described above, alpharadin has been granted Fast Track designation by the U.S. Food and Drug Administration (FDA) for the treatment of castration-resistant (hormone-refractory) prostate cancer in patients with bone metastases. Fast Track is a process designed to facilitate the development and expedite the review of drugs to treat serious diseases and fill an unmet medical need, thereby hopefully leading to earlier drug approval and access by patients. Bayer plans to apply for regulatory approval in Europe and the U.S. by the middle of next year.