ALSYMPCA Trial: Radium-223 Prolongs Life in Some Prostate Cancers
FROM THE GENITOURINARY CANCERS SYMPOSIUM
Major Finding: Radium-223 significantly prolonged overall survival (14.0 vs. 11.2 months) and time to first skeletal-related events (13.6 vs. 8.4 months) with no increase in the rate of adverse events.
Data Source: The randomized phase-III ALSYMPCA trial compared radium-223 chloride vs. placebo in 809 men with metastatic castration-resistant prostate cancer who had at least two bone metastases and no known visceral metastases.
Disclosures: Dr. Sartor disclosed that he is a consultant to Algeta ASA. Dr. Parker disclosed that he is a consultant to Algeta ASA and receives honoraria from Bayer.
SAN FRANCISCO – Radium-223 chloride, the first alpha particle–emitting bone-targeted agent, is efficacious and safe for treating men with bone metastases of castration-resistant prostate cancer, according to a randomized, phase-III trial reported at the Genitourinary Cancers Symposium.
The 809 men in the ALSYMPCA trial had a 30% reduction in the risk of death and a nearly 40% reduction in the risk of a first clinical skeletal-related event if treated with radium-223 chloride, compared with placebo. The agent had a good safety profile as well, with low rates of myelosuppression and, thus far, no cases of secondary cancers.
Trial results were reported in a poster session by Dr. A. Oliver Sartor, Laborde Professor of Cancer Research at Tulane University, New Orleans, and medical director of the Tulane Cancer Center, and in an oral presentation by Dr. Chris Parker of the Royal Marsden NHS Foundation Trust in Sutton, England.
"We believe that this novel alpha pharmaceutical – the very first one to be tested in phase III in all of medicine – may provide a new standard of care for the treatment of patients with bone metastasis in advanced prostate cancer," Dr. Sartor said in a press briefing.
There is every reason to believe that radium-223 "will be very well received by the regulatory agencies, not only in the U.S. but also abroad," he predicted. In fact, it has been submitted for approval in the United States, where the Food and Drug Administration has agreed to fast-track status.
In the question-and-answer period following the oral presentation, Dr. Anthony V. D’Amico of the Dana-Farber Cancer Institute, Boston, said that the trial’s findings were "quite striking," but he questioned radium-223’s long-term safety, especially should the drug be eyed for treatment of less advanced cancer.
"Oftentimes, when we see a result like this, it then gets transferred back into earlier stages of disease. The one thing you can’t assess here are late effects, particularly leukemias and second cancers, like bone sarcomas, because patients die very quickly," he noted. "So caution would have to be thought of before one would administer such a drug even in a clinical trial in earlier settings when people have long life expectancies."