A novel orally active gonadotropin-releasing hormone antagonist, relugolix, is a potential substitute for injectable GnRH antagonists in controlled ovarian stimulation in assisted reproductive technology.

PURPOSE: To evaluate the efficacy of an oral gonadotropin-releasing hormone antagonist (GnRH Ant), relugolix (R), for assisted reproductive technology (ART). METHODS: We enrolled women undergoing ART using a GnRH Ant for controlled ovarian stimulation. We compared R; 20 mg/day with cetrorelix acetate (C); 0.125 mg. C was administered to 88 women in 2019, and R to 93 women in 2020. Clinical outcomes associated with ART were assessed in both groups. RESULTS: The luteinizing hormone levels on the day of human chorionic gonadotropin injection in the R group (1.26 ± 0.93 IU/L) were significantly lower than those in the C group (2.85 ± 3.02 IU/L). There were no cases in which egg retrieval was canceled in both groups. The total doses of gonadotropins administered were greater in the R group compared with the C group. The number of days of GnRH Ant administration in the R group (1.71 ± 0.57 days) was significantly longer compared with the C group (1.48 ± 0.58 days). The number of oocytes collected, fertilization rates, and pregnancy rates (R; 47.1% vs C; 45.8%) did not differ between the two groups. CONCLUSION: An orally active GnRH Ant, relugolix, when used in controlled ovarian stimulation for ART, showed comparable clinical outcomes with cetrorelix.

Pregnancy outcomes following different protocols of controlled ovarian hyperstimulation in couples undergoing intrauterine insemination.

Clomiphene citrate (CC), letrozole and cetrorelix acetate are frequently used agents in controlled ovarian hyperstimulation (COH). However, these three agents have not yet been compared to one another regarding their pregnancy outcomes. The present study was designed to retrospectively compare pregnancy outcomes among the three aforementioned agents. This study involved infertile couples with an infertility duration of at least 2 years, ages 18 to 42 years and who were referred to have their first intrauterine insemination (IUI) treatment cycle. All patients underwent COH with recombinant follicle-stimulating hormone (rFSH) plus CC (n = 118), letrozole (n = 81), or cetrorelix acetate (n = 62), followed by IUI. Using the one-way multivariate analysis of covariance to control female patients' ages, patients stimulated with cetrorelix acetate/rFSH or CC/rFSH had higher numbers of preovulatory follicles than women stimulated with letrozole/rFSH (P < .02), whereas women stimulated with cetrorelix acetate/rFSH had a thicker endometrium than women stimulated with CC/rFSH (P < .0005). Biochemical pregnancy rates were similar among the three protocols of COH. However, women stimulated with letrozole/rFSH showed clinical pregnancy rates higher than those stimulated with CC/rFSH (P = .003) or cetrorelix acetate/rFSH (P = .03) and subclinical abortion rates lower than those stimulated with CC/rFSH or cetrorelix acetate/rFSH (P = .009). Of the different protocols of COH, the odds of having a clinical pregnancy was 3.1 times greater for women stimulated with letrozole/rFSH than women stimulated with CC/rFSH (P = .004) and 2.8 times greater for women stimulated with letrozole/rFSH than women stimulated with cetrorelix acetate/rFSH (P = .03). Our observations show that increased numbers of preovulatory follicles or endometrium thickness do not necessarily improve pregnancy outcomes, because pregnancy outcomes are also subjected to the type of COH used agent. In this regard, letrozole produced fewer preovulatory follicles and did not significantly increase endometrium thickness, but significantly improved pregnancy outcomes in comparison to CC and cetrorelix acetate.

The GnRH analogues affect novel neuropeptide SMIM20/phoenixin and GPR173 receptor expressions in the female rat hypothalamic-pituitary-gonadal (HPG) axis.

The recently discovered peptide phoenixin (PNX) and its receptor GPR173 are novel factors that exhibit a large spectrum of regulatory activity, especially when considered as a central modulator of GnRH-related hormonal control of reproductive processes. It has been already proven that GnRH agonists and antagonists can modulate peptidergic signalling in the HPG axis. Despite these findings, there is so far no information regarding the influence of treatment with GnRH analogues on SMIM20/phoenixin signalling in the hypothalamic-pituitary-gonadal axis. In the current study, SMIM20/phoenixin and GPR173 mRNA levels were measured in the hypothalamus, pituitary and ovaries of female rats in the dioestrus phase following treatment with GnRH-R agonist (buserelin) and antagonist (cetrorelix) using quantitative real-time PCR. The serum PNX concentrations were also estimated with ELISA technique. The hypothalamic, hypophyseal and especially ovarian levels of SMIM20 mRNA were increased after both buserelin and cetrorelix administration. The GPR173 expressions were in turn decreased in the hypothalamus and pituitary. Treatment with the GnRH analogues led to the modulation of SMIM20/phoenixin and GPR173 mRNA expression in the female rat hypothalamic-pituitary-gonadal axis. By identifying buserelin and cetrorelix as novel modulators of phoenixin signalling in the animal HPG axis, these results cast new light on the GnRH analogues mode of action and contribute to a better understanding of the mechanisms responsible for the hormonal control of reproduction.

GnRH Antagonists Produce Differential Modulation of the Signaling Pathways Mediated by GnRH Receptors.

Commercial gonadotropin-releasing hormone (GnRH) antagonists differ by 1-2 amino acids and are used to inhibit gonadotropin production during assisted reproduction technologies (ART). In this study, potencies of three GnRH antagonists, Cetrorelix, Ganirelix and Teverelix, in inhibiting GnRH-mediated intracellular signaling, were compared in vitro. GnRH receptor (GnRHR)-transfected HEK293 and neuroblastoma-derived SH-SY5Y cell lines, as well as mouse pituitary LßT2 cells endogenously expressing the murine GnRHR, were treated with GnRH in the presence or absence of the antagonist. We evaluated intracellular calcium (Ca2+) and cAMP increases, cAMP-responsive element binding-protein (CREB) and extracellular-regulated kinase 1 and 2 (ERK1/2) phosphorylation, ß-catenin activation and mouse luteinizing-hormone ß-encoding gene (Lhb) transcription by bioluminescence resonance energy transfer (BRET), Western blotting, immunostaining and real-time PCR as appropriate. The kinetics of GnRH-induced Ca2+ rapid increase revealed dose-response accumulation with potency (EC50) of 23 nM in transfected HEK293 cells, transfected SH-SY5Y and LßT2 cells. Cetrorelix inhibited the 3 × EC50 GnRH-activated calcium signaling at concentrations of 1 nM-1 µM, demonstrating higher potency than Ganirelix and Teverelix, whose inhibitory doses fell within the 100 nM-1 µM range in both transfected HEK293 and SH-SY5Y cells in vitro. In transfected SH-SY5Y, Cetrorelix was also significantly more potent than other antagonists in reducing GnRH-mediated cAMP accumulation. All antagonists inhibited pERK1/2 and pCREB activation at similar doses, in LßT2 and transfected HEK293 cells treated with 100 nM GnRH. Although immunostainings suggested that Teverelix could be less effective than Cetrorelix and Ganirelix in inhibiting 1 µM GnRH-induced ß-catenin activation, Lhb gene expression increase occurring upon LßT2 cell treatment by 1 µM GnRH was similarly inhibited by all antagonists. To conclude, this study has demonstrated Cetrorelix-, Ganirelix- and Teverelix-specific biased effects at the intracellular level, not affecting the efficacy of antagonists in inhibiting Lhb gene transcription.

Evaluation of ovarian and metabolic effects of GnRH modulators in two rat models of polycystic ovary syndrome.

Gonadotropin-releasing hormone (GnRH) modulators are widely used in numerous reproductive conditions including infertility. Several clinical studies showed mixed results regarding the efficacy of GnRH modulators in patients with polycystic ovary syndrome (PCOS). Along with this, few preclinical studies focus on the effect of GnRH modulators in PCOS-induced animals. Therefore, the present study was designed to study the effect of leuprolide and cetrorelix on hormonal, metabolic, and menstrual dysfunction PCOS rats. Prepubertal female rats were divided into four groups: Group I received a normal pellet diet and Groups II, III, and IV received 40% high-fat diet for 105 days. Similarly, adult female rats were divided into four groups: Group I received 1% carboxymethylcellulose (CMC) and Groups II, III, and IV received letrozole (1 mg/kg, per oral [p.o.] in 1% CMC) for 21 days. Thereafter, leuprolide (2.5 µg/rat, s.c.) and cetrorelix (10 µg/kg, subcutaneous [s.c.]) treatment were given to Group III and Group IV animals, respectively, for 21 days. Oral glucose tolerance test, lipid profile, fasting glucose, insulin, estrus cycle, hormonal profile, ovary weight, ovarian histopathological changes, and LHR and FSHR expressions were measured. Treatment with leuprolide and cetrorelix did not improve glucose intolerance, insulin level, insulin sensitivity indices, sex hormone levels, lipid profile, and estrus cycle. Only testosterone level, total cholesterol level, and follicular development were improved. Therefore, it was concluded that both leuprolide and cetrorelix showed improvement in follicular development, which could be helpful for improving fertility in PCOS.

Clinical experience with an ovarian stimulation protocol for intrauterine insemination adopting a gonadotropin releasing hormone antagonist at low dose.

Studies testing the effectiveness of GnRH antagonists in controlled ovarian stimulation (COS) for intrauterine insemination (IUI) have provided controversial results. The present study was undertaken to evaluate, whether the use of a half of the conventional dose of the GnRH antagonist cetrorelix can be effective in increasing the successful rate of IUI cycles. Patients started COS with human menopausal gonadotropin (hMG) on day three of the menstrual cycle. Cetrorelix was started when at least one follicle of ≥14 mm, was detected at the ultrasound scan, according to the flexible multiple daily dose protocol, and continued until the trigger day with recombinant hCG. Patients adopting GnRH antagonist at low dose had a pregnancy rate (21.7%) that was significantly higher (p < 0.05) in comparison to women receiving hMG only (8.7%). These results suggest that adding a reduced dose of GnRH antagonist to the COS for IUI cycles significantly improves the outcome of the procedure.

Influence of leucine-enkephalin on pituitary-ovary axis of the cichlid fish Oreochromis mossambicus.

The present investigation was conducted to elucidate the influence of an opioid peptide, leucine-enkephalin (L-ENK), on the reproductive axis of the tilapia Oreochromis mossambicus. In the first experiment, administration (i.p.) of 25, 100, and 300 µg L-ENK to the stripped female tilapia, for a period of 22 days, resulted in a significantly higher number of stage I follicles compared to those of initial controls and experimental controls, whereas the mean number of stage II and III follicles and serum levels of E2 did not significantly differ among different experimental groups. A significant increase in the number of stage V (fully ripened) follicles was concomitant with significant reduction in the follicular diameter in 25 or 100 µg L-ENK-treated fish compared to those of experimental controls. However, significant reduction in the mean number and diameter of these follicles was observed in 300 µg L-ENK-treated fish compared to those of experimental controls and 25 or 100 µg L-ENK-treated fish. In the second experiment, the stimulatory effect of 25 µg L-ENK on the ovary was abolished in combination with gonadotropin-releasing hormone antagonist (GnRH-A). In conclusion, these results suggest that L-ENK exerts stimulatory as well as inhibitory effects on the ovary in a dose-dependent manner, and that these effects are possibly mediated through the GnRH, for the first time in fish.

Triptorelin and cetrorelix induce immune responses and affect uterine development and expressions of genes and proteins of ESR1, LHR, and FSHR of mice.

CONTEXT: GnRH immunity can reduce the expression of pituitary GnRH levels, and cause the changes in reproductive behaviors. It is unclear whether triptorelin (TRI) and cetrorelix (CET) immunity influences uterine development and expression of follicle-stimulating hormone receptor (FSHR), luteinizing hormone receptor (LHR), and estradiol receptor 1 (ERS1) in the uterus. OBJECTIVE: The study investigated the effects of active immunity of GnRH agonist and antagonist on uterine development, microstructures, expression of hormone receptors mRNAs, and proteins in uteri. MATERIALS AND METHODS: One hundred and five mice were assigned into CET, TRI, and control groups (CG). Mice in CET-1, CET-2, and CET-3 (n = 15) were subcutaneously injected with 10, 20, and 40 µg CET antigens for seven days, respectively. Mice in TRI-1, TRI-2, and TRI-3 were injected with 10, 20, and 40 µg TRI antigens for seven days, respectively. The qPCR and Western blot were implemented to determine expressions of ESR1, LHR and FSHR mRNAs, and proteins. RESULTS: Compared with CG, the uterine weights of CET-1, CET-2, and CET-3 increased by 42.86, 62.86, and 10.00% on day 35 (p < 0.05), respectively. Uterine weights of TRI-2, TRI-3 reduced by 28.57% and 11.43% (p < 0.05), respectively. The uterine cavity in CET-1, CET-2, and CET-3 increased; the uterine wall became thick. The cytoplasm of endometrial epithelial cells (EEC) increased slightly. In TRI group, the uterine wall thinned. Uterine cavity became narrow slightly in TRI-1. Numbers of uterine glands reduced. The endometrium epithelial thickness (EET) in CET-1 and CET-2 increased by 68.21% and 79.46% (p < 0.05), respectively. EET in TRI-1 was decreased by 13.69%. Uterine wall thicknesses (UWT) in CET-1 and CET-2 were higher than CG, with the increment of 28.59% and 30.72%. UWT of TRI-1, TRI-2, and TRI-3 reduced by 29.35, 15.36, and 14.41%, respectively. Expressions of ESR1, FSHR, and LHR mRNAs in CET and TRI mice increased. ESR1 and FSHR protein levels increased in all experimental mice (p < 0.05), with a maximum of TRI-3. LHR protein levels of the CET decreased. LHR protein levels of TRI group increased, with a maximum of TRI-3 (p < 0.05). ESR1 protein level had significant negative correlations to mRNA expressions of ESR1, LHR, and FSHR. CONCLUSIONS: CET immunity promoted the uterine development, improved EET and UWT, and also promoted the expressions of ESR1 and FSHR protein levels. It lessened the LHR protein levels. TRI immunity blocked EET and UWT, inhibited uterine growth and development. The efficacy of CET immunity was more obvious than TRI.

Hypothalamic gonadotropin-releasing hormone (GnRH) receptor neurons fire in synchrony with the female reproductive cycle.

Gonadotropin-releasing hormone (GnRH) controls mammalian reproduction via the hypothalamic-pituitary-gonadal (hpg) axis, acting on gonadotrope cells in the pituitary gland that express the GnRH receptor (GnRHR). Cells expressing the GnRHR have also been identified in the brain. However, the mechanism by which GnRH acts on these potential target cells remains poorly understood due to the difficulty of visualizing and identifying living GnRHR neurons in the central nervous system. We have developed a mouse strain in which GnRHR neurons express a fluorescent marker, enabling the reliable identification of these cells independent of the hormonal status of the animal. In this study, we analyze the GnRHR neurons of the periventricular hypothalamic nucleus in acute brain slices prepared from adult female mice. Strikingly, we find that the action potential firing pattern of these neurons alternates in synchrony with the estrous cycle, with pronounced burst firing during the preovulatory period. We demonstrate that GnRH stimulation is sufficient to trigger the conversion from tonic to burst firing in GnRHR neurons. Furthermore, we show that this switch in the firing pattern is reversed by a potent GnRHR antagonist. These data suggest that endogenous GnRH acts on GnRHR neurons and triggers burst firing in these cells during late proestrus and estrus. Our data have important clinical implications in that they indicate a novel mode of action for GnRHR agonists and antagonists in neurons of the central nervous system that are not part of the classical hpg axis.

Effects of Cetrorelix on Ovary and Endometrium Prior to Anti-PD-L1 Antibody in Murine Model.

BACKGROUND: Recent anti-cancer agents, immune checkpoint inhibitors (ICIs), have emerged as effective agents targeting the programmed cell death protein-1 (PD-1)/programmed death-ligand 1 (PD-L1) pathway. While the administration of gonadotropin-releasing hormone (GnRH) analogs before cytotoxic agents is known to preserve female reproductive organ function, the potential effects of ICIs and the protective impact of GnRH analogs on female reproductive organs, especially concerning ovarian reserve and endometrial receptivity, remain unknown. In this study, we attempted to elucidate the protective or regenerative effect on the female reproductive organ of cetrorelix prior to anti-PD-L1 antibody administration. METHOD: Using a murine model, we examined the effects of Anti-PD-L1 antibody treatment on ovarian and uterine morphology, compared them with controls, and further assessed any potential protective effect of cetrorelix, a GnRH analog. Histological examinations and quantitative reverse transcription polymerase chain reaction were employed to study the morphological changes and associated gene expression patterns. RESULTS: Anti-PD-L1 treatment led to a significant depletion of primordial/primary ovarian follicles and impaired decidualization in uterine stromal cells. However, while pretreatment with cetrorelix could restore normal decidualization patterns in the uterus, it did not significantly ameliorate ovarian follicular reductions. Gene expression analysis reflected these observations, particularly with marked changes in the expression of key genes like Prl and Igfbp1, pivotal in uterine decidualization. CONCLUSION: Our study underscores the potential reproductive implications of cetrorelix treatment prior to Anti-PD-L1 therapy, shedding light on its short-term protective effects on the uterus. Further studies are necessary to understand long-term and clinical implications.

Effects of pulsatile intravenous follicle-stimulating hormone treatment on ovarian function in women with obesity.

OBJECTIVE: To establish conditions for effective hypothalamic suppression in women with normal and high body mass index (BMI) and test the hypothesis that intravenous (IV) administration of pulsatile recombinant follicle-stimulating hormone (rFSH) can overcome the clinically evident dysfunctional pituitary-ovarian axis in women with obesity. DESIGN: Prospective interventional study. SETTING: Academic medical center. PATIENT(S): Twenty-seven normal-weight women and 27 women with obesity, who were eumenorrheic and aged 21-39 years. INTERVENTION(S): Two-day frequent blood sampling study, in early follicular phase, before and after cetrorelix suppression of gonadotropins and exogenous pulsatile IV rFSH administration. MAIN OUTCOME MEASURE(S): Serum inhibin B and estradiol (E2) levels (basal and rFSH stimulated). RESULT(S): A modified gonadotropin-releasing hormone antagonism protocol effectively suppressed production of endogenous gonadotropins in women with normal and high BMIs, providing a model to address the functional role of FSH in the hypothalamic-pituitary-ovarian axis. The IV rFSH treatment resulted in equivalent serum levels and pharmacodynamics in normal-weight women and those with obesity. However, women with obesity exhibited reduced basal levels of inhibin B and E2 and a significantly decreased response to FSH stimulation. The BMI was inversely correlated with serum inhibin B and E2. In spite of this observed deficit in ovarian function, pulsatile IV rFSH treatment in women with obesity resulted in E2 and inhibin B levels comparable with those in normal-weight women, in the absence of exogenous FSH stimulation. CONCLUSION(S): Despite normalization of FSH levels and pulsatility by exogenous IV administration, women with obesity demonstrate ovarian dysfunction with respect to E2 and inhibin B secretion. Pulsatile FSH can partially correct the relative hypogonadotropic hypogonadism of obesity, thereby providing a potential treatment strategy to mitigate some of the adverse effects of high BMI on fertility, assisted reproduction, and pregnancy outcomes. CLINICAL TRIAL REGISTRATION NUMBER: ClinicalTrials.gov #NCT02478775.

Characterization by LC-MS/MS of oxidized products identified in synthetic peptide somatostatin and cetrorelix submitted to forced oxidative stress by hydrogen peroxide: Two case studies.

In a broader scenario, the forced degradation studies provided by the ICH guidelines for Q1A, Q1B, and Q2B degradation studies allow to know the CQA of the molecule used as a drug product, to determine the appropriate analytical methods, excipients, and storage conditions ensuring the quality of the drug, its efficacy, and patient safety. In this study, we focused our attention on understanding how oxidative stress is performed by H2 O2 -impacted small synthetic peptides that do not contain residues susceptible to oxidation such as methionine. Among the amino acids susceptible to oxidation, methionine is the most reactive and depending on the structure of the protein where it is exposed, it tends to oxidize by converting into methionine sulfone or methionine sulfoxide by oxidation of its sulfur atom. Scouting experiments obtained by forced oxidative stress conditions are presented on two small synthetic peptides that do not contain any methionine residues spiked with different amounts of H2 O2 , and they are analyzed by LC-MS/MS. Less frequent oxidation products than those commonly observed on proteins/peptides-containing methionine have been characterized on both peptides. The study demonstrated that somatostatin, by means of one residue of tryptophan on the molecule, can generate traces of several oxidized products detected by UPLC-MS. Furthermore, even at a negligible level, oxidation on tyrosine and proline in cetrorelix that does not contain methionine nor tryptophan has been detected by UHPLC-MS/MS. Identification and quantification of oxidized species were achieved by high-resolution MS and MS/MS experiments. Thus, FDSs undoubtedly aid the evaluation of the CQAs as an important component of the characterization package as recommended by HAs and ICH, facilitating the understanding of unforeseen features of the studied molecule used as drugs.

Combination treatment of recombinant growth differentiation factor-9 and Cetrorelix improves gestational origin of the polycystic ovarian syndrome in female rats.

AIMS: Polycystic ovary syndrome (PCOS) is a hyper-androgenic endocrinopathy prevalent in premenopausal women with no cure available. The current study aimed to investigate the therapeutic effect of recombinant GDF-9 and Cetrorelix on the gestational origin of dehydroepiandrosterone (DHEA) induced PCOS in postnatal pups' delivered to rat dams. MAIN METHODS: The body weight measurement, blood and serum analysis for glucose tolerance, lipid profile, liver enzymes, sex hormones (Testosterone, Estradiol, and Progesterone), estrus cyclicity assessment, histological staining of ovary and liver, molecular markers expressions of pro-inflammatory by qRT-PCR and immuno-histochemistry technique for folliculogenesis genes and histological staining studies of liver and ovary were done. KEY FINDINGS: The combinational treatment was found to normalize the biochemical parameters and reduction in the estrus irregularity by altering the sex hormones as well as the glucose metabolism and insulin resistance via HOMA-IR value. Further, molecular markers expression confirmed the pro-inflammatory (IL-1ß, TNF-α, and IL-6) and folliculogenesis (GDF-9, BMPR2, and TGF-ßR1) genes associated with PCOS were improved by combinational therapy. SIGNIFICANCE: In conclusion, rGDF-9 could be a potential therapeutic agent in combination with Cetrorelix as a better treatment regime for metabolic and reproductive phenotypes in PCOS. However, the effect of rGDF-9 on infertility-associated phenotypes in PCOS needs further evaluation.

What is the optimal GnRH antagonist protocol for ovarian stimulation during ART treatment? A systematic review and network meta-analysis.

BACKGROUND: Several GnRH antagonist protocols are currently used during COS in the context of ART treatments; however, questions remain regarding whether these protocols are comparable in terms of efficacy and safety. OBJECTIVE AND RATIONALE: A systematic review followed by a pairwise and network meta-analyses were performed. The systematic review and pairwise meta-analysis of direct comparative data according to the PRISMA guidelines evaluated the effectiveness of different GnRH antagonist protocols (fixed Day 5/6 versus flexible, ganirelix versus cetrorelix, with or without hormonal pretreatment) on the probability of live birth and ongoing pregnancy after COS during ART treatment. A frequentist network meta-analysis combining direct and indirect comparisons (using the long GnRH agonist protocol as the comparator) was also performed to enhance the precision of the estimates. SEARCH METHODS: The systematic literature search was performed using Embase (Ovid), MEDLINE (Ovid), Cochrane Central Register of Trials (CENTRAL), SCOPUS and Web of Science (WOS), from inception until 23 November 2021. The search terms comprised three different MeSH terms that should be present in the identified studies: GnRH antagonist; assisted reproduction treatment; randomized controlled trial (RCT). Only studies published in English were included. OUTCOMES: The search strategy resulted in 6738 individual publications, of which 102 were included in the systematic review (corresponding to 75 unique studies) and 73 were included in the meta-analysis. Most studies were of low quality. One study compared a flexible protocol with a fixed Day 5 protocol and the remaining RCTs with a fixed Day 6 protocol. There was a lack of data regarding live birth when comparing the flexible and fixed GnRH antagonist protocols or cetrorelix and ganirelix. No significant difference in live birth rate was observed between the different pretreatment regimens versus no pretreatment or between the different pretreatment protocols. A flexible GnRH antagonist protocol resulted in a significantly lower OPR compared with a fixed Day 5/6 protocol (relative risk (RR) 0.76, 95% CI 0.62 to 0.94, I2 = 0%; 6 RCTs; n = 907 participants; low certainty evidence). There were insufficient data for a comparison of cetrorelix and ganirelix for OPR. OCP pretreatment was associated with a lower OPR compared with no pretreatment intervention (RR 0.79, 95% CI 0.69 to 0.92; I2 = 0%; 5 RCTs, n = 1318 participants; low certainty evidence). Furthermore, in the network meta-analysis, a fixed protocol with OCP resulted in a significantly lower OPR than a fixed protocol with no pretreatment (RR 0.84, 95% CI 0.71 to 0.99; moderate quality evidence). The surface under the cumulative ranking (SUCRA) scores suggested that the fixed protocol with no pretreatment is the antagonist protocol most likely (84%) to result in the highest OPR. There was insufficient evidence of a difference between fixed/flexible or OCP pretreatment/no pretreatment interventions regarding other outcomes, such as ovarian hyperstimulation syndrome and miscarriage rates. WIDER IMPLICATIONS: Available evidence, mostly of low quality and certainty, suggests that different antagonist protocols should not be considered as equivalent for clinical decision-making. More trials are required to assess the comparative effectiveness of ganirelix versus cetrorelix, the effect of different pretreatment interventions (e.g. progestins or oestradiol) or the effect of different criteria for initiation of the antagonist in the flexible protocol. Furthermore, more studies are required examining the optimal GnRH antagonist protocol in women with high or low response to ovarian stimulation.

Comparing Progesterone Primed Ovarian Stimulation (PPOS) to GnRH Antagonist Protocol in Oocyte Donation Cycles.

Background: Progesterone-primed ovarian stimulation (PPOS) protocol is based on the principle of preventing pre-mature luteinising hormone surge during ovarian stimulation using progesterone. Aims: In this study, we aimed to compare the cost-effectiveness of PPOS over GnRH antagonist cycles in oocyte donor cycles where freeze all is a norm. Settings and Design: It is a prospective cohort study with 130 participants. Materials and Methods: We included all women undergoing oocyte donation using PPOS protocol and antagonist protocol at our centre. Fifty-seven belonged to the PPOS group and were given medroxyprogesterone acetate (MPA) and 73 belonged to the GnRH antagonist group who received cetrorelix. The primary outcome was the number of mature oocyte retrieved at OPU and the cost involved per stimulation cycle. Statistical Analysis Used: For normally distributed observations, we used t-test, and for the variables of non-normal distribution, Mann-Whitney U-test was used. The significance was accepted for P < 0.05. Results: The baseline clinical characteristics of the donors were comparable with a mean age of 25.42 ± 2.90 years, body mass index of 24.00 ± 4.00 kg/m2 and antral follicle count of 18.63 ± 5.23. The duration of stimulation was similar in both the groups as well as the total gonadotropin dose required was not significantly different. The number of mature oocytes retrieved was same in both the groups (10.41 ± 4.04 with antagonist and 10.25 ± 3.23 with PPOS, P = 0.964). There were no reported cases of severe ovarian hyperstimulation syndrome (OHSS) in any of the groups. The incidence of mild-to-moderate OHSS in the antagonist group was 5.4% and in the PPOS group was 3.6%, and the difference was not significant (P = 0.69). The cost per mature oocyte (M2) was significantly higher in the antagonist protocol in comparison to the PPOS protocol (INR 9485.69 ± 5751.11 vs. Rs. 5945.86 ± 2848.59, respectively, P < 0.001). Conclusion: Our study identifies PPOS protocol using MPA to be more cost-effective and patient-friendly than conventional GnRH antagonist protocol in oocyte donor cycles.

Identification and structural elucidation of a new cetrorelix methylene dimer impurity in cetrorelix acetate by using LC-MS/MS.

Cetrorelix, a potent third generation of luteinizing hormone releasing hormone (LHRH) antagonist, is a synthetic decapeptide used for treatment of infertility, prostatic hypertrophy and sexual hormone-dependent tumors. The approved drug of cetrorelix (Cetrotide, Asta Medica AG, Frankfurt, Germany.), was used for prevention of premature ovulation in patients undergoing a controlled ovarian stimulation (COS), followed by oocyte pick-up and assisted reproductive techniques, and has been shown safe and effective in controlled ovarian stimulation. Nevertheless, the study of aggregation products of cetrorelix was rarely reported. A simple liquid chromatography mass spectrometry (LC-MS/MS) method was developed for separation, identification and characterization of a new cetrorelix methylene dimer impurity in cetrorelix. The chromatographic separation was achieved on an XSelect Peptide CSH ™C18 column (150 × 4.6 mm, 3.5 µm particle size) using gradient elution with a mobile phase of ammonium formate buffer (pH 3.0, 20 mM), acetonitrile at a flow rate 1.0 mL min-1, and an ultraviolet detection wavelength of 226 nm. The new cetrorelix methylene dimer impurity was characterized by LC-MS/MS and it characteristic fragment ions were summarized. A simple, fast and accurate method was established for the determination of the molecular weight and structure of the new cetrorelix methylene dimer impurity. In this study, the results showed that the cetrorelix was highly unstable in formaldehyde conditions. In addition, it is proposed that the impact of formaldehyde in the environment on the quality of cetrorelix acetate for Injection should be evaluated during the production process.

GnRH Antagonist Protocol With Cessation of Cetrorelix on Trigger Day Improves Embryological Outcomes for Patients With Sufficient Ovarian Reserve.

Objective: To evaluate the efficiency and validity of cessation of cetrorelix on trigger day during gonadotropin releasing hormone antagonist (GnRH-ant)-controlled ovarian stimulation of in vitro fertilization (IVF) cycles. Methods: In this retrospective study, a total of 1271 patients undergoing initial IVF cycles following the GnRH-ant protocol were enrolled; 832 patients received cetrorelix on trigger day (Group A) and 439 patients ceased cetrorelix on trigger day (Group B). We compared demographic characteristics, embryological and clinical outcomes between the two groups. A Poisson regression model was used to identify factors that significantly affected embryological outcomes. Patients were further divided into subgroups according to anti-Mullerian hormone (AMH) and age, to assess associations between ceasing cetrorelix on trigger day and embryological outcomes. Results: There was a significant improvement on embryological outcomes in patients who ceased cetrorelix on trigger day, and there were no significant differences in clinical outcomes or preovulation rates between the two groups. Furthermore, for patients with 1.1 ≤ AMH ≤ 4.7 ng/ml, all embryological outcomes were significantly higher in Group B compared with Group A. For patients with AMH > 4.7 ng/ml, the number of oocytes retrieved, fertilization rate (2PN) of IVF cycles and proportion of day 3 good quality embryos were all significantly higher in Group B. For patients with age < 35 years, all the embryological outcomes, besides the number of available embryos, were significantly higher in Group B than in Group A. There were no differences in embryological outcomes between the two groups when patients were stratified based on age > 35 years or AMH < 1.1 ng/ml. Conclusion: GnRH-ant protocol with cessation of cetrorelix on trigger day improved embryological outcomes for young patients or patients with sufficient ovarian reserve, and was effective at preventing preovulation.

Comparison of the effects of Duphaston and Cetrotide on oocyte and embryo quality in women undergoing ICSI: A cross-sectional study.

BACKGROUND: Premature luteinizing hormone (LH) surge is one of the causes for assisted reproductive technology cycle cancellation, and it is needed to find novel approaches with improved efficacy and safety profile. OBJECTIVE: To compare the effects of Duphaston and Cetrotide on the prevention of premature LH surge and characteristics of retrieved follicles and embryos in women undergoing intracytoplasmic sperm injection. MATERIALS AND METHODS: In this retrospective cross-sectional study, 200 patients who were administrated recombinant follicle-stimulating hormone from the third day of menstruation cycle were included. When the follicular diameter reached above 13-14 mm, Cetrotide was prescribed in the control group, while in the case group, Duphaston was taken orally from the third day of cycle. The retrieved oocytes were fertilized in vitro by intracytoplasmic sperm. The level of hormones on the third day of menstruation and the characteristic of follicles, oocytes, and embryos were compared between the two groups. RESULTS: Duphaston successfully inhibits premature LH surge. There was no significant difference in the level of follicle-stimulating hormone, estradiol, and LH between the case and control groups (p > 0.05). However, results also showed that Duphaston causes more oocyte retrieval in comparison with Cetrotide (p = 0.04). Although, the number of follicles above 14 mm, mature oocyte, and the total number of viable embryos in the case group was slightly higher, it did not reach a significant difference compared with the control group (p > 0.05). CONCLUSION: Duphaston could be used as an appropriate medication instead of gonadotropin-releasing hormone antagonists in women undergoing controlled ovarian hyperstimulation. Duphaston prescription not only prevents premature LH surge but also improves the number of retrieved oocytes.

The effects of LH inhibition with cetrorelix on cumulus cell gene expression during the luteal phase under ovarian coasting stimulation in cattle.

Cumulus cells have an important role to play in the final preparation of the oocyte before ovulation. During the final phase of follicular differentiation, FSH levels are low and LH maintains follicular growth; however, it is not known if at that time LH has an influence on cumulus cells inside the follicle. In humans, LH is often inhibited to avoid a premature ovulatory LH surge. This procedure provides a tool to investigate the role of LH in follicular development. In this study, we investigated the impact of suppressing LH using the GnRH antagonist cetrorelix during an ovarian coasting stimulation protocol on the transcriptome of bovine cumulus cells (CC). Oocytes were collected twice from 6 dairy cows. For the first collection, the cows received FSH twice daily for 3 d, followed by FSH withdrawal for 68 h as a control protocol. For the second collection, the same stimulation protocol was used, but the cows also received, starting on day 2 of FSH stimulation, a GnRH antagonist once a day until recovery of the cumulus-oocyte complexes (COC). Half of the COC were subjected to in vitro maturation, fertilization, and culture to assess blastocyst rates. The other half of the COC underwent microarray analysis (n = 3 cows, 2 treatments, 6 oocyte collections) and qRT-PCR (n = 6 cows: 3 microarray cows +3 other cows, 2 treatments, 12 oocyte collections). The differential expression of specific genes was confirmed by RT-qPCR: decrease of ATP6AP2, SC4MOL, and OSTC and increase of PTGDS in the LH-inhibited condition. The global transcriptomic analysis of cumulus cells demonstrated that the inhibition of LH secretion may decrease survival and growth of the follicle. Moreover, the results suggested that LH may be important to cumulus for the maintenance of cellular mechanisms such as global RNA expression, protein and nucleic acid metabolism, and energy production. These results support the hypothesis that LH support is important during the final part of follicle maturation through its influence on the cumulus cells.

NAV3, a Tumor Suppressor Gene, Is Decreased in Uterine Leiomyoma Tissue and Cells.

NAV 3 is a tumor suppressor of unknown function in leiomyomas. The objective of this study is to assess NAV3 expression and its potential role in human uterine leiomyomas. NAV3 protein expression was examined in patient leiomyoma and patient-matched myometrial tissue samples by Western blot and immunohistochemistry. NAV3 mRNA and protein expression was assessed in leuprolide acetate- and cetrorelix-treated cell line leiomyoma samples. RNAseq analysis of placebo-treated leiomyoma compared with myometrium demonstrated the presence of transcripts encoding for several neuronal proteins. For NAV3, RNA sequence analysis demonstrated decreased expression in leiomyoma as compared with myometrium (0.86 ± 0.03 fold). Presence of NAV3 mRNA was also decreased in leiomyoma surgical samples (0.43 fold ± 0.05, p = 0.026) compared with patient-matched myometrium. Confirmatory qRT-PCR results on immortalized leiomyoma and myometrial cell lines similarly demonstrated a decrease in expression of NAV3 in leiomyomas (0.28 ± 0.02, p = 0.00075). Immunohistochemical analysis demonstrated a significant decrease in NAV 3 protein in leiomyomas (H-score 154.7 ± 6.2) as compared with myometrium (H-score; 312.5 ± 14.7, p < 0.0001). Leuprolide acetate-treated leiomyoma cells demonstrated an increase in NAV 3 mRNA expression (1.53 ± 0.13, p < 0.0001). Similarly, Western blot analysis on leuprolide-treated leiomyoma cells showed a non-significant increase in NAV 3 protein expression (1.26 ± 0.09, p = 0.063). NAV 3, a tumor suppressor in numerous cancers, is decreased in leiomyoma cells and tissue compared with myometrium, and increased by GnRH analog treatment, suggesting that NAV3 may mediate steroid hormone-independent leiomyoma regulation by GnRH analogs.