ID11916 is an orally active compound functioning as both an androgen receptor (AR) antagonist and a phosphodiesterase 5 (PDE5) inhibitor. It disrupts androgen binding to AR, impedes nuclear translocation, and blocks androgen-dependent transcriptional activity of AR, while simultaneously elevating intracellular cGMP levels by inhibiting PKG activation. Moreover, ID11916 exhibits potent anticancer effects in prostate cancer cell lines VCaP and 22Rv1, as well as in AR-positive breast cancer cell line SK-BR-3.