Clinical Research Directory

Oral GnRH Antagonist (Linzagolix) Versus Injectable GnRH Antagonist for Ovarian Stimulation in IVF/ICSI

This study compares two medications used to prevent a premature hormone surge (LH surge) during controlled ovarian stimulation for in vitro fertilization (IVF). The standard approach uses an injectable GnRH antagonist (ganirelix or cetrorelix), given as a daily injection under the skin. This study evaluates linzagolix, an oral GnRH antagonist already approved for uterine fibroids and endometriosis, used here for the first time in ovarian stimulation (off-label use). Women undergoing IVF/ICSI at CENTRO AMBRA will be randomly assigned (1:1) to receive either oral linzagolix (200 mg/day) or the standard injectable antagonist. The study's hypothesis is that linzagolix is not inferior to the injectable antagonist in the number of mature (MII) eggs retrieved, within a pre-specified margin of 2.0 oocytes, while offering the advantage of oral rather than injectable administration. A separate, non-randomized group of women who are clinically indicated for a progestin-based stimulation protocol (PPOS) with a freeze-all strategy will be enrolled at the same time for descriptive comparison. Secondary objectives include how effectively each treatment suppresses the LH surge, whether a GnRH agonist can be used to safely trigger final egg maturation under linzagolix, the occurrence of ovarian hyperstimulation syndrome (OHSS) and other safety outcomes, the length of stimulation and amount of hormone medication needed, and embryology outcomes such as fertilization and blastocyst formation rates. The study plans to enroll approximately 189 women in total.

LE + CC vs. LE for Ovulation Induction

This randomized controlled trial (RCT) aims to evaluate whether, in infertile women with WHO II/IV ovulatory disorders, a combination of letrozole (LE) and clomiphene citrate (CC) compared to LE alone, result in higher live birth rates. The study is designed as an open-label, multicenter RCT across six fertility clinics in Vietnam. Participants will be randomized into two groups: (1) LE + CC , (2) LE alone. The primary outcome measure is the live birth rate after one treatment cycle. Based on prior data, the live birth rate for IUI in letrozole cycles is estimated at 12%. To detect a 10% increase in live birth rates with CC, 436 couples are needed (α = 0.05, power = 80%). Additionally, the live birth rate after IUI with LE-induced ovulation is approximately 18.7% (Diamond et al., 2015). To detect a 10% increase with CC, 560 couples are required (α = 0.05, power = 80%). Considering a 5% loss to follow-up and protocol deviations, the study plans to recruit 600 participants (150 per arm).