Radium-223 (Alpharadin) is a novel bone targeted treatment for advanced prostate cancer.
At the recent European Multidisciplinary Cancer Congress in Stockholm (EMCC 2011), Dr Chris Parker from The Royal Marsden Hospital presented results of the phase 3 ALSYMPCA trial that showed both delayed time to first skeletal-related event (SRE) AND an overall survival (OS) benefit for those men with advanced prostate cancer taking radium-223. This is the first time a product in the bone category has shown such a survival benefit – neither denosumab or zoledronic acid can claim that distinction.
Unlike the recent regulatory approvals for cabazitaxel (Jevtana) and abiraterone acetate (Zytiga), which focused on the post-docetaxel setting, the ALSYMPCA trial included not only those who had already received cytotoxic therapy, but also pre-docetaxel patients, who were unable to take chemotherapy.
As Dr Parker mentions in the interview that he kindly gave in Stockholm (the first video interview on Biotech Strategy Blog), radium-223, assuming it gains regulatory approval, will provide a new treatment option for the considerable population of men with bone metastases who may be too weak, too old or otherwise unable to take chemotherapy such as docetaxel.
Radium-223 is, therefore, potentially good news for this “neglected” population of prostate cancer patients.
In the video interview, Dr Parker talks about why he believes combining radium-223 with abiraterone acetate (Zytiga) makes sense.
He also talks about some of the challenges that radium-223 still faces, such as how to monitor treatment and work out the optimal dose. It is hard to believe that Algeta/Bayer would undertake a phase 3 registration study of a novel bone targeted agent without any bone imaging in the protocol!
As Cora Sternberg mentioned in the educational session at EMCC 2011, in advanced prostate cancer, “80% of the disease is in the bone.” radium-223 is an exciting radiopharmaceutical that is likely to be “practice changing” once approved.
That’s not to say there are not going to be challenges and issues with its commercialization. Algeta/Bayer have a lot of work to do now that it is clearly on fast track for FDA approval next year.
Dr Parker also mentions in his interview that radium-223 is a weak alpha emitter and the radiation can be blocked by paper or glass. It therefore requires no special facilities, such as lead lined rooms, for its administration, unlike beta emitters. The latter have been challenging commercially in the past for this reason.
However, it does require a radiopharmaceutical license, which means that community based oncologists and urologists in the United States will most likely have to refer patients to receive their injection at an approved facility where there is a nuclear medicine/radiology department or equivalent expertise. In Europe, this is less of an issue given most cancer patients are treated in outpatient clinics associated with hospitals, whereas in the US, the majority of patients are seen in the community setting.
Despite that, it is hard to believe that radium-223 (Alpharadin) will not have a major impact on the advanced prostate cancer market if it can be commercially supplied without difficulty and the details are worked out on how to use it optimally and monitor progress. I am sure we will hear more on these issues at cancer conferences next year.
Looking at the other indications for bone targeted agents such as denosumab and zoledronic acid, radium-223 or a similar radiopharmaceutical could offer potential benefits in other tumor types such as breast cancer, were there are also skeletal related events (SRE’s) associated with treatment.
The video interview I did with Dr Chris Parker is well worth watching, and I am grateful to him for taking the time out of his busy schedule at the recent Cancer Congress in Stockholm. Since this is a first for Biotech Strategy Blog, do let me know if this is something you’d like to see more of moving forwards.
Challenges & opportunities for radium-223 (Alpharadin) in advanced prostate cancer – an interview with Dr Chris Parker