At the on-going AUA Meeting, Dr. Howard Scher along with a collaborating group of medical oncologists reported their data from a Phase I-II trial of MDV3100 in castration-resistant prostate cancer (CRPC).

MDV3100 is an oral androgen receptor (AR) antagonist (androgen blocker). Their findings show that it binds to the androgen receptors (AR) on the surface of prostate cancer cells with greater affinity then other currently used drugs and prevents nuclear translocation of AR with greater efficiency than bicalutamide (casdoex).

MDV3100 uses a different pathway so, unlike bicalutamide, MDV3100 blocks DNA binding of AR, causing tumor cell apoptosis and more importantly, it has demonstrated no known agonist activity when AR is over expressed. The bottom line result is that unlike bicalutamide, MDV3100 will not stimulate AR as an agonist, or feed the cancer.

For the purpose of the study, the anti-tumor activity of MDV3100 was a