According to a company media release, the full results of the ALSYMPCA trial were presented Saturday at the European Multidisciplinary Cancer Congress (EMCC). This is the trial of the injectable radioactive agent radium-223 chloride (Alpharadin®) in men with symptomatic, metastatic, castration-resistant prostate cancer (mCRPC).
In June this year, as previously reported, Bayer Healthcare had announced that the ALSYMPCA trial had been halted because radium-223 had shown a statistically significant, 2.8-month survival benefit compared to a placebo in the treatment of patients randomized to the active agent or the placebo in this trial.
The ALSYMPCA trial was an international, randomized, double-blind, placebo-controlled Phase III study of radium-223 chloride + best standard of care compared with a placebo + best standard of care in men with symptomatic mCRPC. The trial enrolled 922 patients at more than 100 centers in 19 countries. All patients enrolled had either failed prior docetaxel-based chemotherapy or were not eligible to be treated with docetaxel-based chemotherapy. Patients enrolled in the study were given up to six intravenous treatments with radium-223 chloride or placebo. There was a period of 4 weeks between each treatment.
The study met its primary endpoint (overall survival) and all of the major secondary endpoints, as indicated by the following results:
- Treatment with radium-223 improved overall survival by 44 percent compared to placebo (p = 0.00185; hazard ratio [HR] = 0.695).
- Average (median) overall survival was
- 14.0 months for men treated with radium-223
- 11.2 months for men treated with placebo
- Average (median) time to first skeletal-related event was
- 13.6 monthsfor men treated with radium-223
- 8.4 months for men treated with placebo
- Levels of total alkaline phosphatase (ALP) were normalized in
- 33 percent of men treated with radium-223
- 1 percent of men treated with placebo
- Treatment with radium-223 improved time to PSA progression by 49 percent compared to placebo (p = 0.00015; HR = 0.671).
- Common non-hematologic adverse events (occurring in at least 15 percent of patients) included
- Bone pain (in 43 percent of radium-223 patients vs. 58 percent of placebo-treated patients)
- Nausea (34 vs. 32 percent)
- Diarrhea (22 vs. 13 percent)
- Constipation (18 vs. 18 percent)
- Vomiting (17 vs. 13 percent)
- The most common hematologic adverse event was anemia (in 27 percent of radium-223 patients vs. 27 percent of placebo-treated patients)
- The most common grade 3 and grade 4 adverse event was bone pain (18 percent of radium-223 patients vs. 23 percent of placebo-treated patients).
Based on these and related data, Bayer Healthcare has stated that the company plans to file for regulatory approval to market Alpharadin in both the U.S. and Europe in mid-2012. This suggests that the product might get approved for clinical use in the USA some time early in 2013.