A CYP17A1 inhibitor is a type of drug that inhibits the enzymeCYP17A1.[1] CYP17A1 inhibitors work by blocking specific enzyme functions, impacting androgen biosynthesis.
Mechanism of action
CYP17A1 inhibitors may inhibit one or both of the enzyme’s functions: 17α-hydroxylase and 17,20-lyase. Some inhibitors are selective and target only the 17,20-lyase function, while others inhibit both functions.[2] By inhibiting these enzymatic functions, CYP17A1 inhibitors prevent the conversion of pregnanesteroids into androgens like testosterone. This action classifies them as androgenbiosynthesis inhibitors and functional antiandrogens.
CYP17A1 inhibitors, such as abiraterone acetate, are primarily used in the treatment of prostate cancer. These drugs reduce androgen levels, which helps to slow the progression of prostate cancer in patients with castration-resistant prostate cancer.[4]
Combination with glucocorticoids
Non-selective CYP17A1 inhibitors that inhibit both the 17α-hydroxylase and 17,20-lyase functions must be administered alongside a glucocorticoid (e.g., prednisone) to prevent adrenal insufficiency and mineralocorticoid excess. This precaution is necessary because non-selective inhibitors can disrupt cortisol production, leading to hormone imbalances.[5]
