The present invention relates to a compound of formula (I) wherein A, B, R1, R2, R3, R4 and R5 are as defined in claim 1, or pharmaceutically acceptable salts thereof are disclosed. The compounds of formula (I) possess utility as cytochrome P450 monooxygenase 11A1 (CYP11A1) inhibitors. The compounds are useful as medicaments in the treatment of steroid receptor, for example androgen receptor or estrogen receptor, dependent diseases and conditions, such as cancer including prostate cancer and breast cancer.