Alpharadin Improves Survival in Advanced Prostate Cancer

An investigational radiopharmaceutical has been found to improve survival in patients with advanced prostate cancer in a phase 3 study that is still ongoing. Only 4 other products have managed to show such a survival benefit.

The result emerged during an interim analysis of the Alpharadin in Symptomatic Hormone-Refractory Prostate Cancer (ALSYMPCA) trial.

Alpharadin, which is generically known as radium-223 chloride, is used to treat castration-resistant (hormone-refractory) prostate cancer in patients with bone metastases.

Radium-223 chloride is a novel alpha particle–emitting nuclide under development by Bayer, which licensed it in from the Norwegian company Algeta ASA in September 2009. The company just announced that the product has been given a US Food and Drug Administration Fast Track designation, which expedites the review of drugs that are aimed at serious diseases and that fill an unmet medical need.

The survival result in the interim analysis was highlighted by Chris Parker, MD, from the Royal Marsden Hospital, Sutton, United Kingdom, and Oliver Sartor, MD, from Tulane Cancer Center, New Orleans, Louisiana, in a letter appearing in this week's edition of the New England Journal of Medicine.

They write: "Radium-223 is a novel alpha-pharmaceutical that specifically targets bone metastases and has shown excellent efficacy and safety in a randomised phase 2 trial (Lancet Oncol. 2007;8:587-594)."

The ongoing phase 3 trial, known as ALSYMPCA, recently had "a positive interim analysis for the overall survival end-point," they note.

"Radium-223 now joins a select list of just 5 drugs that have been shown to improve overall survival in patients with advanced prostate cancer," they add.

For a long time, the only drug with a survival advantage in this setting was docetaxel, but it has recently been joined by 3 new products, all approved in the United States: abiraterone (Zytiga, Cougar Biotechnology), cabazitaxel (Jevtana, Sanofi-Aventis), and the novel prostate cancer vaccine sipuleucel-T (Provenge, Dendreon).

The ongoing ALSYMPCA trial (NCT00699751) has an estimated primary completion data of October 2012 and an estimated study completion date of December 2013. The study is double-blind and placebo-controlled, with a 2:1 allocation of drug to placebo (saline). Both are administered intravenously at intervals of 4 weeks, for 6 sessions. The primary endpoint is overall survival.