Gonadotrophins: The future

Impaired Gonadotropin-Lowering Effects of Metformin in Postmenopausal Women with Autoimmune Thyroiditis: A Pilot Study

Metformin has been found to reduce elevated gonadotropin levels. Hashimoto's thyroiditis is the most common thyroid disorder in iodine-sufficient areas, and it often develops in postmenopausal women. The aim of this study was to investigate whether autoimmune thyroiditis determines the impact of metformin on gonadotrope secretory function. Two matched groups of postmenopausal women were studied: 35 with euthyroid Hashimoto's thyroiditis (group A) and 35 without thyroid disorders (group B). Throughout the study, all participants received oral metformin (2.55-3 g daily). Plasma glucose, insulin, gonadotropins, estradiol, progesterone, thyrotropin, free thyroid hormones, prolactin, adrenocorticotropic hormone, insulin-like growth factor-1, hsCRP, thyroid peroxidase, and thyroglobulin antibody titers were measured at the beginning of the study and six months later. At entry, both groups differed in thyroid peroxidase antibody titers, thyroglobulin antibody titers, and hsCRP levels. In group A, baseline antibody titers correlated positively with hsCRP and negatively with insulin sensitivity. Although metformin improved glucose homeostasis and reduced hsCRP levels in both study groups, these effects were more pronounced in group B than in group A. Only in group B did metformin decrease FSH levels and tend to reduce LH levels. Thyroid antibody titers and the levels of the remaining hormones did not change throughout the study. The impact of metformin on gonadotropin levels correlated with their baseline values and the degree of improvement in insulin sensitivity, as well as with the baseline and treatment-induced reduction in hsCRP. Moreover, the impact on gonadotropins and insulin sensitivity in group A depended on baseline antibody titers. The obtained results indicate that coexisting autoimmune thyroiditis impairs the gonadotropin-lowering effects of metformin in postmenopausal women.

Allosteric modulation of gonadotropin receptors

Gonadotropins regulate reproductive functions by binding to G protein-coupled receptors (FSHR and LHCGR) expressed in the gonads. They activate multiple, cell-specific signalling pathways, consisting of ligand-dependent intracellular events. Signalling cascades may be modulated by synthetic compounds which bind allosteric sites of FSHR and LHCGR or by membrane receptor interactions. Despite the hormone binding to the orthosteric site, allosteric ligands, and receptor heteromerizations may reshape intracellular signalling pattern. These molecules act as positive, negative, or neutral allosteric modulators, as well as non-competitive or inverse agonist ligands, providing a set of new compounds of a different nature and with unique pharmacological characteristics. Gonadotropin receptor allosteric modulation is gathering increasing interest from the scientific community and may be potentially exploited for clinical purposes. This review summarizes the current knowledge on gonadotropin receptor allosteric modulation and their potential, clinical use.

The Conundrum of Poor Ovarian Response: From Diagnosis to Treatment

Despite recent striking advances in assisted reproductive technology (ART), poor ovarian response (POR) diagnosis and treatment is still considered challenging. Poor responders constitute a heterogeneous cohort with the common denominator of under-responding to controlled ovarian stimulation. Inevitably, respective success rates are significantly compromised. As POR pathophysiology entails the elusive factor of compromised ovarian function, both diagnosis and management fuel an ongoing heated debate depicted in the literature. From the criteria employed for diagnosis to the plethora of strategies and adjuvant therapies proposed, the conundrum of POR still puzzles the practitioner. What is more, novel treatment approaches from stem cell therapy and platelet-rich plasma intra-ovarian infusion to mitochondrial replacement therapy have emerged, albeit not claiming clinical routine status yet. The complex and time sensitive nature of this subgroup of infertile patients indicates the demand for a consensus on a horizontally accepted definition, diagnosis and subsequent effective treating strategy. This critical review analyzes the standing criteria employed in order to diagnose and aptly categorize POR patients, while it proceeds to critically evaluate current and novel strategies regarding their management. Discrepancies in diagnosis and respective implications are discussed, while the existing diversity in management options highlights the need for individualized management.

Analysis of patient and nurse preferences for self-administered FSH injection devices in select European markets

Purpose

The purpose of this study was to assess product-specific features for a variety of self-administered injection devices and identify key factors that patients and nurses in select European markets find most important when selecting injection devices for self-administration of recombinant human follicle-stimulating hormone and urinary human follicle-stimulating hormone for fertility/reproductive therapy.

Patients and methods

Patients (N=402) in France, Italy, Spain, Germany, the UK, the Netherlands, and Belgium, as well as reproductive/fertility nurses (N=40) in Germany, Italy, France, Spain, and the Czech Republic were surveyed. All patients were previously prescribed a follicle-stimulating hormone (FSH) treatment for either in vitro fertilization or ovulation induction. Patient and nurse preferences for attributes across all injection devices in the market were obtained via an online questionnaire and evaluated using the maximum differential scaling (MaxDiff) and conjoint analyses, which captured the relative importance of the selected FSH injection device attributes to determine specific qualities in overall product preference.

Results

Both the MaxDiff and conjoint analyses indicated that, for patients and nurses, the ideal FSH injection device would be a highly accurate, multi-use reusable pen injector with a dial-back function that would be easy for both use and education/instruction. Patients and nurses each selected attributes pertinent to their own experiences with the FSH injection device. Categorically, patients valued factors that resulted in minimal impact on daily life, including reduced injection volume to minimize injection-site pain, as well as a reusable device that would be easy to use; nurses placed greater value on a device that would be easy to teach in order to instruct the greatest number of patients while minimizing risk.

Conclusion

Patient and nurse preferences were aligned on certain selected attributes of the FSH products. Although this study was an unbranded examination of attributes across all injection devices currently in the market, results demonstrated that the preferred product attributes were all characteristics of the Ovaleap^® Pen.

Use of various gonadotropin and biosimilar formulations for in vitro fertilization cycles: results of a worldwide Web-based survey

PURPOSE

The purpose of this study was to identify trends in gonadotropin therapy in patients undergoing in vitro fertilization (IVF) treatment worldwide.

METHODS

Retrospective evaluation utilizing the results of a Web-based survey, IVF-Worldwide ( www.IVF-worldwide.com ) was performed.

RESULTS

Three hundred fourteen centers performing a total of 218,300 annual IVF cycles were evaluated. Respondents representing 62.2% of cycles (n = 135,800) did not believe there was a difference between urinary and recombinant gonadotropins in terms of efficacy and live birth rate. Of the respondents, 67.3% (n = 146,800) reported no difference between recombinant and urinary formulations in terms of short-term safety and risk of ovarian hyperstimulation syndrome. In terms of long-term safety using human urinary gonadotropins, 50.6% (n = 110,400) of respondents believe there are potential long-term risks including prion disease. For 95.3% of units (n = 208,000), the clinician was the decision maker determining which specific gonadotropins are used for IVF. Of the units, 62.6% (n = 136,700) identified efficacy as the most important factor in deciding which gonadotropin to prescribe. While most (67.3%, n = 146,800) were aware of new biosimilar recombinant FSH products entering the market, 92% (n = 201,000) reported they would like more information. A fraction of respondents (25.6%, n = 55,900) reported having experience with these new products, and of these, 80.3% (n = 46,200) reported that they were similar in efficacy as previously used gonadotropins in a similar patient group.

CONCLUSIONS

Respondents representing the majority of centers do not believe a difference exists between urinary and recombinant gonadotropins with respect to efficacy and live birth rates. While many are aware of new biosimilar recombinant FSH products entering the market, over 90% desire more information on these products.

Long-acting recombinant follicle-stimulating hormone in random-start ovarian stimulation protocols for fertility preservation in women with cancer

INTRODUCTION

The objective of this study was to assess the effectiveness and potential benefits of the use of long-acting recombinant follicle-stimulating hormone (FSH) in a random-start protocol for fertility preservation in women with cancer.

MATERIAL AND METHODS

This is a retrospective before-and-after study performed between February 2013 and December 2015 in women who underwent ovarian hyperstimulation for oocyte cryobanking using a random-start approach. In the first part of the study period, the women were treated with daily recombinant FSH whereas in the second part the stimulation was initiated with long-acting recombinant FSH. The primary aim of the study was to compare the number of oocytes stored in the two study periods. In all, 140 women were ultimately selected.

RESULTS

Compared with daily recombinant FSH, the use of the long-acting compound was associated with a reduced number of injections (12.5 ± 3.5 vs. 16.4 ± 0.3; p < 0.001) and a longer duration of stimulation (11.4 ± 1.9 vs. 10.6 ± 1.9, p = 0.01). Conversely, the number of oocytes collected (13.7 ± 9.5 vs. 11.3 ± 7.0, p = 0.10) as well as those cryopreserved (11.0 ± 8.0 vs. 9.5 ± 5.8, p = 0.21) did not differ.

CONCLUSIONS

The use of long-acting recombinant FSH in random-start protocols for fertility preservation appears to be a valuable option.

Half-life extended biotherapeutics

INTRODUCTION

Many of the biotherapeutics approved or under development suffer from a short half-life necessitating frequent applications in order to maintain a therapeutic concentration over an extended period of time. The implementation of half-life extension strategies allows the generation of long-lasting therapeutics with improved pharmacokinetic and pharmacodynamic properties.

AREAS COVERED

This review gives an overview of the different half-life extension strategies developed over the past years and their application to generate next-generation biotherapeutics. It focuses on srategies already used in approved drugs and drugs that are in clinical development. These strategies include those aimed at increasing the hydrodynamic radius of the biotherapeutic and strategies which further implement recycling by the neonatal Fc receptor (FcRn).

EXPERT OPINION

Half-life extension strategies have become an integral part of development for many biotherapeutics. A diverse set of these strategies is available for the fine-tuning of half-life and adaption to the intended treatment modality and disease. Currently, half-life extension is dominated by strategies utilizing albumin binding or fusion, fusion to an immunoglobulin Fc region and PEGylation. However, a variety of alternative strategies, such as fusion of flexible polypeptide chains as PEG mimetic substitute, have reached advanced stages and offer further alternatives for half-life extension.

Corifollitropin stimulation in combination with GnRH-antagonists after estradiol valerate pre-treatment. A pilot study on patientfriendly IVF

OBJECTIVE

To demonstrate the feasibility of scheduling an IVF cycle, without disadvantages, in the new patient friendly stimulation protocol using the long acting Corifollitropin Alfa, in combination with GnRH-antagonist protection and GnRH-agonist triggering.

STUDY DESIGN

Two groups of ten patients were admitted in the study. Both received the same stimulation protocol with Corifollitropin Alfa in combination with GnRH-antagonist protection. After ultrasound evaluation on day 7 individually dosed Menopur was added. For triggering final oocyte maturation GnRH-agonists were used. The only difference between the two groups was that in the study group, estradiol valerate 4 mg/day was given from day 25 of the preceding cycle for a period of 10 days, thus postponing the start of follicular growth.

RESULTS

Scheduling the IVF stimulation by the administration of estradiol valerate 4 mg/day did not influence the hormonal curves, nor the embryological results in comparison to patients with the same stimulation, starting their stimulation at the beginning of menstruation. In this pilot study four out of ten patients turned out to be pregnant, demonstrating an acceptable pregnancy rate.

CONCLUSION

The combination of estradiol valerate 4 mg/day pre-treatment with the novel combination of Corifollitropin Alfa stimulation with GnRH-antagonist protection, individually topped off with Menopur, and triggered with GnRH-agonist proved to be a safe, patient-friendly (limited number of injections in comparison to classical IVF) (Patil, 2014) and efficient alternative to classical IVF stimulation protocols, allowing patients - and doctors - to schedule the treatment cycle to their convenience.

Recent advancements in the hormonal stimulation of ovulation in swine

Induction of ovulation for controlled breeding is available for use around the world, and conditions for practical application appear promising. Many of the hormones available, such as human chorionic gonadotropin (hCG), gonadotropin-releasing hormone (GnRH) and its analogs, as well as porcine luteinizing hormone (pLH), have been shown to be effective for advancing or synchronizing ovulation in gilts and weaned sows. Each of the hormones has unique attributes with respect to the physiology of its actions, how it is administered, its efficacy, and approval for use. The timing for induction of ovulation during the follicle phase is critical as follicle maturity changes over time, and the success of the response is determined by the stage of follicle development. Female fertility is also a primary factor affecting the success of ovulation induction and fixed time insemination protocols. Approximately 80%-90% of female pigs will develop mature follicles following weaning in sows and synchronization of estrus in gilts. However, those gilts and sows with follicles that are less developed and mature, or those that develop with abnormalities, will not respond to an ovulatory surge of LH. To address this problem, some protocols induce follicle development in all females, which can improve the overall reliability of the ovulation response. Control of ovulation is practical for use with fixed time artificial insemination and should prove highly advantageous for low-dose and single-service artificial insemination and for use with frozen-thawed and sex-sorted sperm.