Therapeutic effects of an oral gonadotropin-releasing hormone receptor antagonist, relugolix, on preventing premature ovulation in mild ovarian stimulation for IVF

IVF stimulation protocols and outcomes in women with endometriosis

Endometriosis is a complex medical condition with a high prevalence in women of reproductive age. Fertility is compromised in patients with endometriosis, and success in IVF treatments has been a challenge leading to evaluation of different stimulation protocols. The long-standing debate between GnRH agonist long protocols and short GnRH antagonist protocols is being resolved in favor of the latter, since in addition to presenting equivalent results with respect to the traditional option, they have the additional benefit of safety. The good results derived from vitrification techniques have led to the development of new stimulation strategies, such as progestin-primed ovarian stimulation (PPOS), with a greater degree of approval among patients. None of the stimulation protocols currently applied in women with endometriosis has been shown to be superior, so early intervention with an Assisted Reproduction treatment, regardless of the chosen protocol, can provide these women with good chances of motherhood. Women with endometrioma should be counseled for fertility preservation before planned ovarian endometrioma excision. The number of cryopreserved oocytes or embryos can be increased by repeated cycles.

The novel oral gonadotropin-releasing hormone receptor antagonist relugolix is a new option for controlled ovarian stimulation cycles

Purpose

Relugolix is an oral gonadotropin-releasing hormone antagonist (GnRHant), which was first introduced in 2019. This study investigated the effects of the conventional injectable GnRHant formulation and this new oral GnRHant formulation on controlled ovarian stimulation (COS) cycles.

Methods

Relugolix was administered in 126 cycles and conventional GnRHant injection was administered in 658 cycles (controls). The follicle stimulation was performed by an antagonist method, and for final oocyte maturation, recombinant human chorionic gonadotropin (rHCG), or gonadotropin-releasing hormone agonist (GnRHa), or both (dual trigger) were selected. The number of retrieved oocytes was counted and then they were evaluated for subsequent development up to cleavage stage.

Results

The number of retrieved oocytes which was the primary outcome of this research was affected by the combination of GnRHant type and the final oocyte maturation agent. The combination of relugolix and a GnRHa trigger showed a significantly lower number of retrieved oocytes (p < 0.001) than the other combinations.

Conclusions

Relugolix is a new option for COS cycles, but should be carefully combined with the final maturation agent.

Clinical trial approval

This study was conducted after approval by the Medical Corporation Sankeikai Institutional Ethics Committee (approval number: 2019-34).