As of today there are many different potential drugs undergoing phase III evaluations for men with advanced prostate cancer, some of them seem to offer great hope and promise. Considering we just had Provenge finally approved, this is great news.
Sanofi-aventis has a drug under development called cabazitaxel (aka Jevtana). Sanofi-aventis has already filed with the FDA’s Division of Drug Marketing, Advertising and Communications (DDMAC). We can hope for a review sometime this summer and if we are lucky it is possible to have an approval this fall! If approved, it would be used after Taxotere has failed. Given that we are at a dead end for having any approved treatment at that time, this would be a G-d send. Yesterday, at the ASCO Meeting very positive data was reported, including an increase in over all survival.
Bavarian Nordic (B/N) is in the process of testing what might be the next prostate cancer vaccine to become available, Prostvac. They have successfully completed a phase II trial of 125 men with metastatic prostate cancer. The good news, the survival advantage experienced by the trial’s subjects had a statistically significantly longer median overall survival of 8.5 months. At best, the completion of the phase III trials, which have already commenced, is a good four to five years away from being completed.
Another well known and very positive looking “on The horizon drug” is abiraterone. This investigational drug from Cougar is an inhibitor of testosterone production (luteinizing hormone-releasing hormone [LHRH] agonists) from both the testes and adrenal glands. These trials will probably not be completed prior to the mid to end of 2011, so at best we could not have an approval (if all goes well) until the close of 2012 at the earliest.
Millennium-Takeda has made advances in another testosterone inhibitor which looks to have great potential , TAK700. The trials for TAK700 are not as advanced as the trials for abiraterone, so we will need to be even more patient for a potential approval. However, at the ASCO meeting there was very positive data reported.
MDV3100 from Medivation/Astellas, is an exciting potential new androgen blocker “on the horizon.” Currently, the most common blocker we use is casodex, but its useful life is very limited and it is not as effective a testosterone blocker as we need. We are in need of a more complete inhibitor of the Androgen Receptor (AR) and perhaps MDV3100 will provide a strong move in that direction. Additionally, Medivation has announced their intention to start several additional trials to evaluate the best time to use MDV3100.
Algeta, presented data from a phase II study that showed a remarkable two-year survival advantage with its investigational drug, Alpharadin (radium-223), when used as a as a treatment for castrate resistant prostate cancer (CRPC).
The clinical trial involved 64 men with CRPC and showed that more than twice as many men receiving Alpharadin were still alive (10men of 33men) two years following start of treatment compared to those that receive placebo (4 men of 31men).
Currently, there are a few on going phase III trials which will still take a number of years to mature, but the potential survival advantage is very significant, more significant than any other developing treatment.
There have been strides in developing new and better treatments for men with advanced prostate cancer, for this we should be very hopeful. Despite these major steps forward, we remain in a desert. We need all these treatments plus many more. Extending life by two, three or even six months is good, but it is not where we need to be. The fact that I would not even dream of being able to cure advanced prostate cancer itself is a sad commentary on our reality.
Joel T Nowak, MA, MSW