Purity >98%. MDV 3100 is a non-steroidal androgen receptor antagonist (IC50 = 36 nM). It reduces the efficiency of nuclear translocation of the androgen receptor and impairs both its binding to DNA and the recruitment of coactivators. It is orally available and induces tumor regression in mouse models of castration-resistant human prostate cancer. It has applications in advanced cancers that remain dependent on androgen receptor signaling even in the absence of androgen.