Replacement of imidazolyl by pyridyl in biphenylmethylenes results in selective CYP17 and dual CYP17/CYP11B1 inhibitors for the treatment of prostate cancer.

Androgens are well-known to stimulate prostate cancer (PC) growth. Thus, blockade of androgen production in testes and adrenals by CYP17 inhibition is a promising strategy for the treatment of PC. Moreover, many PC patients suffer from glucocorticoid overproduction, and importantly mutated androgen receptors can be stimulated by glucocorticoids. In this study, the first dual inhibitor of CYP17 and CYP11B1 (the enzyme responsible for the last step in glucocorticoid biosynthesis) is described. A series of biphenylmethylene pyridines has been designed, synthesized, and tested as CYP17 and CYP11B1 inhibitors. The most active compounds were also tested for selectivity against CYP11B2 (aldosterone synthase), CYP19 (aromatase), and hepatic CYP3A4. In detail, compound 6 was identified as a dual inhibitor of CYP17/CYP11B1 (IC(50) values of 226 and 287 nM) showing little inhibition of the other enzymes as well as compound 9 as a selective, highly potent CYP17 inhibitor (IC(50) = 52 nM) exceeding abiraterone in terms of activity and selectivity.