Demonstrating (once again) that the U.S. Food and Drug Administration (FDA) moves with alacrity when presented with good data to support the approval of important new therapeutic agents, the agency has today approved enzalutamide (to be known as Xtandi®) for the treatment of men with metastatic castration-resistant prostate cancer (mCRPC) previously treated with docetaxel-based chemotherapy.
A media release issued jointly by Medivation and Astellas Pharma provides additional information about this approval.
Full prescribing information for enzalutamide can be found on the FDA web site.
The “New” Prostate Cancer InfoLink admits that we were not expecting an approval of enzalutamide this quickly, which has to be a testament to both the quality of the New Drug Application (NDA) submitted by the drug’s developers, as well as the commitment of the FDA to turn good applications around on a highly accelerated schedule.
Filed under: Drugs in development, Management, Treatment | Tagged: enzalutamide, MDV3100 |
THE "NEW" PROSTATE CANCER INFOLINK 
Please correct me if I’m wrong, Mike, but for those less familiar, I believe enzalutamide is the generic name for MDV-3100.
MDV3100 was the original “code number” for the drug now known generically as enzalutamide. Yes. The brand name is apparently Xtandi.
How does MDV3100 work differently than XL184 and when would one be recommended over the other for CRPC patients?
Dear Claire:
Enzalutamide (formerly known as MDV3100) is an androgen receptor antagonist. One of the easiest ways to think about how it works is as a sort of “super-antiandrogen”(i.e., a supercharged bicalutamide). You can find a detailed presentation on its mechanism of action if you click here.
Cabozantinib (also known as XL-184) is a very different type of compound called a kinase inhibitor. Specifically it inhibits the MET and VEGFR2 pathways associated with cancer metastasis. We don’t even know (yet) whether it will ever be approved for the treatment of advanced forms of prostate cancer. A detailed presention of the mechanism of action of this drug can be seen if you click here.
My husband started Xtandi on Friday, September 21, 2012. In March of 2010 a second biopsy found that he had high-grade, aggressive cancer (AJCC Stage IV) that had metastasized to the uretha, to the neck of the bladder, and into the bladder. Surgery was not a possibility. He has been on hormone therapy since April 23, 2010. Since then he has also had 35 sessions of IMRT with Cb/Catscan [?], a button TURP [?], Provenge (in February of this year), and three treatments with Taxotere, before starting on Xtandi. His PSA has been rising (now 118 ng/ml); he has bone mets and liver involvement.
We were totally shocked that he needed this treatment so soon. We are praying that it will stop the progression and lower the PSA. We have a doctyor’s appointmen next week. Good luck to all of you who has a loved one with this terrible disease and thank you research doctors for the many hours spent working on this and many other treatments.
Dear Phyllis:
It may take more than a couple of weeks before there is any clear sign that your husband is (or is not) responding to the enzalutamide (Xtandi), so I would caution you not to expect a big and sdden drop in your husband’s PSA in such a short time frame.