Positive Phase III study data has led Algeta and partner Bayer HealthCare Pharmaceuticals to confirm plans to file for approval of the alpha-emitting radiopharmaceutical candidate Alpharadin (radium-223 chloride) in 2012 as a treatment for castration-resistant prostate cancer (CRPC) that has spread to the bone. The 922-patient placebo-controlled Alsympca study compared the treatment of patients with bone metastatic CRPC using either Alpharadin plus standard of care, or placebo plus standard of care.
Data reported at the European Multidisciplinary Cancer Congress in Stockholm showed that the addition of Alpharadin therapy boosted median overall survival from 11.2 months to 14 months, and improved median time to first skeletal-related event by 64%, from 8.4 months to 13.6 months. Treatment using Alpharadin also led to a normalization of total alkaline phosphatase in 32.9% of patients, compared with 0.9% of patients receiving placebo, and led to a 49% improvement in time to prostate-specific antigen progression. Total ALP response, defined as a 30% reduction from baseline, was demonstrated in 43% of Alpharadin-treated patients, but in just 3% of placebo group patients.
In June Bayer and Algeta reported that the Alsympca trial’s independent data monitoring committee had recommended unblinding the study following a preplanned interim analysis because it had met its primary endpoint of significantly improving overall survival. The committee further recommended that patients in the placebo arm be offered treatment with Alpharadin. Bayer Pharma inked worldwide development and commercialization rights to Alpharadin back in 2009. Under terms of the deal, Algeta has an option for up to 50/50 co-promotion and profit-sharing in the U.S.