Inhibitors of the androgen receptor N-terminal domain. Therapies targeting the Achilles' heel of various androgen receptor molecules in advanced prostate cancer

Although prostate cancer responds well to primary endocrine therapies, tumor progression with castration resistant tumor cells almost invariably occurs within a few years. Unfortunately, some CRPC patients do not respond to second-line therapies with abiraterone or enzalutamide. Moreover, patients who initially responded well to second-line hormone therapy develop resistance to abiraterone and/or enzalutamide within a short period of time. Besides an increase of intracellular androgen receptor (AR) levels, the predominant resistance mechanisms include AR aberrations (point mutations, AR splice variants) occurring predominantly at the androgen or ligand binding domain of the AR. The following review delineates recent progress in the development of AR inhibitors that do not depend on androgen binding and represent a putative third generation of AR inhibitors.