The second clinical trial (Trial 2) was a 12-week randomized, double-blind and placebo-controlled trial that enrolled 558 generally healthy postmenopausal women between 40 to 80 years of age (mean years) who, at baseline, had identified moderate to severe dyspareunia as their most bothersome symptom of vulvar and vaginal atrophy. In addition to dyspareunia, women had ≤ 5% superficial cells on vaginal smear and a vaginal pH > 5. Women were randomized in a 2:1 ratio to receive once daily vaginal insert containing mg INTRAROSA (n=376) or placebo (n=182). The primary endpoints and study conduct were the same or similar to those in Trial 1.
In humans, the CYP17A1 gene is largely associated with endocrine effects and steroid hormone metabolism.    Furthermore, mutations in the CYP17A1 gene are associated with rare forms of congenital adrenal hyperplasia, in particular 17α-hydroxylase deficiency/17,20-lyase deficiency and isolated 17,20-lyase deficiency. Overall, CYP17A1 is an important target for inhibition in the treatment of prostate cancer because it produces androgen that is required for tumor cell growth.   Currently, the FDA has approved only one CYP17A1 inhibitor, abiraterone, which contains a steroidal scaffold that is similar to the endogenous CYP17A1 substrates. Abiraterone is structurally similar to the substrates of other cytochrome P450 enzymes involved in steroidogenesis, and interference can pose a liability in terms of side effects. Using nonsteroidal scaffolds is expected to enable the design of compounds that interact more selectively with CYP17A1.  Potent inhibitors of the CYP17A1 enzyme provide a last line defense against ectopic androgenesis in advanced prostate cancer.