Efficacy and safety of ASP1707 for endometriosis-associated pelvic pain: the phase II randomized controlled TERRA study.

Study Question: Does the GnRH antagonist, ASP1707, reduce endometriosis-associated pelvic pain?

Summary Answer: ASP1707 significantly reduced endometriosis-associated pelvic pain in a dose-related manner.

What Is Known Already: GnRH agonists are an effective therapeutic option for endometriosis that is refractory to non-steroidal anti-inflammatory drugs, oral contraceptives, and progestins. However, GnRH agonists cause complete suppression of estradiol (E2), resulting in hypoestrogenic side-effects such as bone loss that may increase the future risk of osteoporotic fractures.

Safety, tolerability and anti-tumour activity of the androgen biosynthesis inhibitor ASP9521 in patients with metastatic castration-resistant prostate cancer: multi-centre phase I/II study.

Background: ASP9521 is a first-in-class orally available inhibitor of the enzyme 17 β-hydroxysteroid dehydrogenase type 5 (17 βHSD5; AKR1C3), catalysing the conversion of dehydroepiandrosterone and androstenedione into 5-androstenediol and testosterone. It has demonstrated anti-tumour activity in in vitro and in vivo preclinical models.

Material And Methods: This first-in-man phase I/II study utilised a 3 + 3 dose escalation design starting at 30 mg ASP9521/day, with the aim of defining a maximum tolerated dose, as defined by the incidence of dose-limiting toxicities.