Comparative pharmacology of a new recombinant FSH expressed by a human cell line

The pregnancy outcomes among women receiving individualized algorithm dosing with follitropin delta: a systematic review of randomized controlled trials

PURPOSE

To investigate whether the ovarian stimulation with follitropin delta in an individualized algorithm-based manner is inferior to recombinant human-follicle stimulating's follitropin alfa or follitropin beta conventional dosing regarding a series of established primary endpoints.

METHODS

We conducted a registered systematic review (CRD42024512792) on PubMed-MEDLINE, Web of Science™, Cochrane Database of Systematic Reviews, and Scopus. Our search was designed to cover all relevant literature, particularly randomized controlled trials. We critically and comparatively analyzed the outcomes for each primary endpoint based on the intervention, reflected by the positive βhCG test, clinical pregnancy, vital pregnancy, ongoing pregnancy, live birth, live birth at 4 weeks, and multiple pregnancies.

RESULTS

Six randomized controlled trials were included in the quality assessment as priority manuscripts, revealing an 83.3% low risk of bias. Follitropin delta led to non-significant differences in each parameter of interest from positive βhCG test (691; 53.44% vs. 602; 46.55%), ongoing pregnancies (603; 53.79% vs. 518; 46.20%), clinical and vital pregnancies (1,073; 52.80% vs. 959; 47.19%), to live birth and at 4 weeks (595; 54.14% vs. 504; 45.85%) with only 2 losses, and even multiple pregnancies (8; 66.66% vs. 4; 33.33%). However, follitropin delta was well-tolerated among hypo- and hyper-responders without significant risk of ovarian hyperstimulation syndrome and/or preventive interventions in contrast with follitropin alfa or follitropin beta.

CONCLUSION

The personalized individualized-based algorithm dosing with follitropin delta is non-inferior to conventional follitropin alfa or follitropin beta. It is as effective in promoting a similar response in women without significant comparable adverse effects.

A prospective proof-of-concept trial on the effect of personalized dosages of follitropin delta in intrauterine insemination

RESEARCH QUESTION

What is the efficacy and safety of individualized follitropin delta dosing for ovarian stimulation in intrauterine insemination (IUI)?

DESIGN

This single-centre, prospective, open-label, single-cohort study involving 106 patients established an original dosing regimen based on body weight and anti-Müllerian hormone (AMH) concentrations, with adjustments based on the ovarian response from the previous IUI cycle. Each participant was enrolled in a maximum of three IUI cycles.

RESULTS

Mean age was 34.5 ± 4.5 years, mean weight 69.2 ± 11.2 kg, mean AMH 15.7 ± 8.6 pmol/l, mean FSH 6.3 ± 2.6 IU/l and mean antral follicle count 16.4 ± 8.2. The percentage of patients who produced more than three mature follicles was 1.9%, 0% and 1.5%, respectively, for the three IUI cycles. The percentage of patients with two or three mature follicles was 34.0%, 36.9% and 47.1% for the three IUI cycles. The clinical pregnancy rate per IUI cycle was 17.9%, 14.3% and 17.6% for the three cycles, with a cumulative clinical pregnancy rate of 40.6%. Out of 258 cycles, 43 (16.7%) resulted in clinical pregnancy, with six of those resulting in multiple pregnancies (14.0%). Two resulted in spontaneous reduction within the first trimester and four resulted in live twin births, representing only 1.6% of the total cycles.

CONCLUSIONS

This study is the first to utilize follitropin delta for stimulation in IUI. It demonstrates that individualized dosing is both effective and safe, resulting in satisfactory cumulative pregnancy rates and an acceptable multiple pregnancy rate, thus achieving the primary objectives of the research.

Efficacy and safety of follitropin delta for ovarian stimulation in vitro fertilization/ intracytoplasmic sperm injection cycles: a systematic review with meta-analysis

BACKGROUND

Follitropin delta is a novel recombinant follicle stimulating hormone preparation uniquely expressed in a human fetal retinal cell line by recombinant DNA technology. To date, no systematic review was available about the safety and the efficacy of the follitropin delta. The objective of this study was systematically reviewing the available literature and to provide updated evidence regarding the efficacy-safety profile of follitropin delta when compared to other gonadotropin formulations for ovarian stimulation in in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) cycles.

METHODS

An extensive search was performed to identify phase 1, phase 2 and phase 3 RCTs in humans focused on follitropin delta use for ovarian stimulation in IVF/ICSI cycles. The risk of bias and the overall quality of the evidence was analyzed. All data were extracted and analyzed using the intention-to-treat principle and expressed per woman randomized.

RESULTS

A total of 7 RCTs (1 phase 1 RCT, 2 phase 2 RCTs and 4 phase 3 RCTs) were included in the qualitative analysis, whereas data of three phase 3 RCTs were meta-analyzed. All trials compared personalized recombinant follitropin delta treatment versus conventional recombinant follitropin alfa/beta administration in potentially normo-responder patients who receive ovarian stimulation in GnRH antagonist IVF/ICSI cycles. No difference between two regimens was detected for clinical pregnancy rate [odds ratio (OR) 1.06; 95% confidence intervals (CI): 0.90, 1.24; P = 0.49; I2 = 26%], ongoing pregnancy rate (OR 1.15; 95%CI: 0.90, 1.46; P = 0.27; I2 = 40%), and live birth rate (OR 1.18; 95%CI: 0.89, 1.55; P = 0.25; I2 = 55%). No data were available regarding cumulative success rates. The rate of adoption of strategies to prevent ovarian hyperstimulation syndrome (OHSS) development (OR 0.45; 95%CI: 0.30, 0.66; P < 0.0001; I2 = 0%), and the rate of both early OHSS (OR 0.62; 95%CI: 0.43, 0.88; P = 0.008; I2 = 0%) and all forms of OHSS (OR 0.61; 95%CI: 0.44, 0.84; P = 0.003; I2 = 0%) were significantly lower in the group of patients treated with personalized follitropin delta treatment compared to those treated with conventional follitropin alfa/beta administration.

CONCLUSION

Personalized follitropin delta treatment is associated with a lower risk of OHSS compared to conventional follitropin alfa/beta administration in potentially normo-responder patients who receive ovarian stimulation in GnRH antagonist IVF/ICSI cycles. The absence of cumulative data does not allow definitive conclusions to be drawn regarding the comparison of the effectiveness of the two treatments.

PROTOCOL STUDY REGISTRATION

CRD42023470352 (available at http://www.crd.york.ac.uk/PROSPERO ).

Follitropin delta combined with menotropin in patients at risk for poor ovarian response during in vitro fertilization cycles: a prospective controlled clinical study

BACKGROUND

The maximum daily dose of follitropin delta for ovarian stimulation in the first in vitro fertilization cycle is 12 μg (180 IU), according to the algorithm developed by the manufacturer, and based on patient's ovarian reserve and weight. This study aimed to assess whether 150 IU of menotropin combined with follitropin delta improves the response to stimulation in women with serum antimullerian hormone levels less than 2.1 ng/mL.

METHODS

This study involved a prospective intervention group of 44 women who received 12 μg of follitropin delta combined with 150 IU of menotropin from the beginning of stimulation and a retrospective control group of 297 women who received 12 μg of follitropin delta alone during the phase 3 study of this drug. The inclusion and exclusion criteria and other treatment and follow-up protocols in the two groups were similar. The pituitary suppression was achieved by administering a gonadotropin-releasing hormone (GnRH) antagonist. Ovulation triggering with human chorionic gonadotropin or GnRH agonist and the option of transferring fresh embryos or using freeze-all strategy were made according to the risk of developing ovarian hyperstimulation syndrome.

RESULTS

Women who received follitropin delta combined with menotropin had higher estradiol levels on trigger day (2150 pg/mL vs. 1373 pg/mL, p < 0.001), more blastocysts (3.1 vs. 2.4, p = 0.003) and more top-quality blastocysts (1.8 vs. 1.3, p = 0.017). No difference was observed in pregnancy, implantation, miscarriage, and live birth rates after the first embryo transfer. The incidence of ovarian hyperstimulation syndrome did not differ between the groups. However, preventive measures for the syndrome were more frequent in the group using both drugs than in the control group (13.6% vs. 0.6%, p < 0.001).

CONCLUSIONS

In women with serum antimullerian hormone levels less than 2.1 ng/mL, the administration of 150 IU of menotropin combined with 12 μg of follitropin delta improved the ovarian response, making it a valid therapeutic option in situations where ovulation triggering with a GnRH agonist and freeze-all embryos strategy can be used routinely.

TRIAL REGISTRATION

U1111-1247-3260 (Brazilian Register of Clinical Trials, available at https://ensaiosclinicos.gov.br/rg/RBR-2kmyfm ).

Inadvertent Administration of 72 µg of Follitropin-Δ for Three Consecutive Days Does Not Appear to Be Dangerous for Poor Responders: A Case Series

Follitropin delta (Δ) is a recombinant human follicle-stimulating hormone (rFSH), like natural human FSH, that can stimulate the development and growth of multiple follicles. Treatment with Follitropin-Δ may cause mild to severe adverse reactions, such as the risk of developing ovarian hyperstimulation syndrome, resulting in nausea, vomiting and diarrhea, weight loss, respiratory difficulty, stomach swelling and discomfort of the pelvic area, headaches, and fatigue. To date, the effects of a Follitropin-Δ overdosage are unknown, and no data are reported in the scientific literature or in the drug data sheet. Therefore, this study aimed to describe the effects of Follitropin-Δ overdosages in poorly responding women who underwent IVF cycles. This is a descriptive case series of four nulligravid, poorly responding patients, two of whom made requests for fertility preservation. Four poorly responding patients who were prescribed 20.0 µg/day of Follitropin-Δ for three consecutive days wrongly injected the total cartridge of 72 µg Follitropin-Δ every day. After the incorrect injection of Follitropin-Δ, the patients continued their controlled ovarian stimulation and underwent vaginal ovarian pick up. The analyzed patients had no side effects or adverse reactions. The evaluations reported in this case series showed that the accidental use of 72 µg/day of Follitropin-Δ for three days did not cause side effects or adverse reactions in poor responders.

Follicle-Stimulating Hormone Biological Products: Does Potency Predict Clinical Efficacy?

Follicle-stimulating hormone (FSH), together with luteinizing hormone (LH) and human chorionic gonadotropin (hCG), plays a fundamental role in human reproduction. The discovery of FSH and other gonadotropins was a defining moment in our understanding of reproduction and led to the development of many treatments for infertility. In this regard, exogenous FSH has been used to treat infertility in women for decades. Today, several recombinant and highly purified urinary forms of FSH are used in medically assisted reproduction (MAR). However, differences in the macro- and micro-heterogeneity of FSH result in a variety of FSH glycoforms, with glycoform composition determining the bioactivity (or potency), pharmacokinetic/pharmacodynamic (PK/PD) profiles, and clinical efficacy of the different forms of FSH. This review illustrates how the structural heterogeneity of FSH glycoforms affects the biological activity of human FSH products, and why potency does not predict effects in humans in terms of PK, PD, and clinical response.

How to dose follitropin delta for the first insemination cycle according to the ESHRE and ASRM guidelines; a retrospective cohort study

BACKGROUND

Follitropin Delta (FD) is indicated exclusively for in-vitro fertilization however, being a gonadotropin it could be used for other purposes. A dosing algorithm exists for FD and IVF but is needed for intrauterine insemination (IUI) cycles. The objective of this study is to determine dosing for FD for the first controlled ovarian hyperstimulation (COH) cycle according to current stimulation guidelines.

RESULTS

A retrospective study of 157 subjects from a single university fertility center from January 2017 to March 2020, was performed. All patients stimulated with FD for IUI were included. The number of failed, normal, or overstimulation cycles was determined based on stimulating not more than 2 mature follicles. We then stratified the group based on the AFC, AMH, and body weight. Of 157 subjects, 49% stimulated correctly, 5.6% failed and 45.4% overstimulated. An analysis of the COH IUI cycles based on stratification and over or lack of stimulation per published guidelines found that women with a bodyweight < 80 kg or AMH ≥ 1.5 ng/ml or AFC ≥ 10 initially stimulate with FD 2.0 to 3.0mcg daily. For women with an AFC of 6-9 stimulate with Follitropin Delta 3.0mcg daily. For women with an AFC < 6 or serum AMH < 1.5 ng/ml stimulate with FD 3.0-4.0mcg daily. For women with body weight > 80 kg stimulate initially with daily with 4.0-6.0mcg FD.

CONCLUSIONS

Follitropin Delta can be used safely for controlled ovarian stimulation and insemination at doses easily dispensed by the current methods of delivery, within the current published guidelines for follicle development.

A Narrative Review Discussing the Efficiency of Personalized Dosing Algorithm of Follitropin Delta for Ovarian Stimulation and the Reproductive and Clinical Outcomes

Background: Follitropin delta is the third recombinant human follicle-stimulating hormone (r-hFSH) expressed in a host cell line of human fetal retinal origin that currently emphasizes that the actual tendency of administration is a personalized dosing algorithm based on the anti-Müllerian hormone (AMH) and body mass index (BMI) for ovarian stimulation. Methods: In this context, we aimed, in the present manuscript, to gather all available data published between 2018-2022 regarding the co-administration and administration of follitropin delta and the clinical outcomes reported following an in vitro fertilization (IVF). Results: Follitropin delta is non-inferior in contrast to its previously launched agents for ovarian stimulation, enhancing a similar-to-superior response reflected by both the reproductive and pregnancy outcomes in parallel with a low risk of ovarian hyperstimulation syndrome (OHSS), being well tolerated. The body weight and AMH level are factors that may influence the outcome in a patient. Despite controversy and results that refute these arguments on several occasions, follitropin delta exceeds the benefits of conventional dosing with either follitropin alfa or follitropin beta. Thus, all post hoc, derived analyses and subsets of patients that participated in subsequent studies support this statement. Conclusions: Despite the relatively limited spectrum of data in the current literature, most authors brought potent proof, supporting the subsequent use of this drug depending on the patient's profile and overcoming ethnic-related limitations. Although others contradict these observations, this topic and drug possess substantial potential, which is why additional studies are mandatory to fill the existing gaps in our knowledge and expand these experiences at a larger scale supported by the obtained reproductive and clinical outcomes that clearly indicate an overcoming of all limitations.

Comparing pregnancy rates following ovarian stimulation with follitropin-Δ to follitropin -α in routine IVF: A retrospective analysis

STUDY OBJECTIVES

Follitropin-Δ, a new recombinant follicle stimulation hormone, uses a fixed daily dose producing a predictable ovarian response while using less gonadotropins compared to follitropin-α. We report clinical outcomes comparing each in the routine IVF setting and further compare qualified to disqualified subjects based on previous randomized controlled trial (RCT) inclusion criteria.

STUDY DESIGN

Retrospective analysis of all cycles performed by a single provider between January 2020 to January 2021. All IVF cycles without patient inclusion-exclusion criteria were considered for the analysis. Clinical outcomes in two groups (follitropin-Δ vs follitropin-α ± 75 IU human menopausal gonadotropin (hMG) in expected poor responders) were compared. In addition, comparisons were made between qualified versus disqualified subgroups.

RESULTS

No differences in baseline demographics, number of MII oocytes, fertilization/MII oocyte, percent of good quality embryos were noted. Compared to those using follitropin-α, follitropin-Δ resulted in lower daily (170 vs 211 IU/d, p = 0.002) and total Gn used (1739 vs 2194 IU, p = 0.003). Optimal range response (8-14 oocytes) (22/44 [50 %] vs 78/203 [38.6 %]; p = 0.10) and fresh (fCP) and cumulative clinical pregnancy (cCP) rates per transfer (29.5 % vs 24.1 % and 35 % vs 25.1 %, p = 0.08) were similar between groups. Based on previous RCTs, those who would have qualified compared to those who would have disqualified, patients using follitropin-Δ were just as likely to have an optimal oocyte response (qualified: 48 % vs disqualified: 57.1 %) and resulted in similar cCP (41.4 % vs 25 %, p-0.23).

CONCLUSIONS

While follitropin-Δ requires less daily and total dosing compared to follitropin-α, optimal range of retrieved oocytes and clinical outcomes appear to be comparable. Using RCT inclusion criteria, similar findings were noted in those who would have qualified compared to disqualified patients.

Pharmacokinetics and Safety of Follitropin Delta in Gonadotropin Down-Regulated Healthy Chinese Women

BACKGROUND

Follitropin delta, a novel recombinant follicle-stimulating hormone (rFSH) preparation derived from a human cell line, has different pharmacokinetic and pharmacodynamic properties compared with existing rFSH preparations expressed by Chinese hamster ovary cells (CHO).

OBJECTIVES

The objective of this study was to assess the pharmacokinetic characteristics, dose proportionality, and safety of follitropin delta in healthy Chinese women.

METHODS

This was a phase I, randomized, open-label study. Twenty-four healthy Chinese women were randomized (1:1:1) to receive a single subcutaneous administration of follitropin delta 12, 18, or 24 μg. The pharmacokinetic parameters (maximum observed serum concentration [C_max], time to reach C_max [t_max], area under the serum concentration-time curve from dosing to infinity [AUC_∞], and elimination phase half-life [t_½]) of follitropin delta were derived using noncompartmental analysis.

RESULTS

Following a single subcutaneous administration of follitropin delta 12, 18, or 24 μg, mean C_max (0.388, 0.677, and 0.825 ng/mL, respectively) and AUC_∞ (41.3, 62.9, and 83.1 h·ng/mL, respectively) increased in a dose-proportional manner. The median t_max was 24 h, and the mean t_½ was in the range of 50.5-60.9 h. All treatment-related adverse events were categorized as mild, except for one case of urticaria from the follitropin delta 18-μg dose group which was considered moderate. Only one woman presented with elevation of alanine transaminase and aspartate aminotransferase at the follow-up visit, which was reported as a treatment-emergent adverse event. There were no injection-site reactions and none of the participants showed any confirmed presence of treatment-induced anti-FSH antibodies.

CONCLUSIONS

The administration of single doses of follitropin delta to healthy Chinese women demonstrated dose-proportional pharmacokinetics over the dose range of 12-24 μg, and these doses were well tolerated.

CLINICAL TRIAL REGISTRATION

Clinicaltrials.gov registration no. NCT04150861.

OUP accepted manuscript

STUDY QUESTION

SUMMARY ANSWER

WHAT IS KNOWN ALREADY

STUDY DESIGN, SIZE, DURATION

PARTICIPANTS/MATERIALS, SETTING, METHODS

MAIN RESULTS AND THE ROLE OF CHANCE

LIMITATIONS, REASONS FOR CAUTION

WIDER IMPLICATIONS OF THE FINDINGS

STUDY FUNDING/COMPETING INTEREST(S)

TRIAL REGISTRATION NUMBER

TRIAL REGISTRATION DATE

DATE OF FIRST PATIENT’S ENROLMENT

Purification Process of a Recombinant Human Follicle Stimulating Hormone Biosimilar (Primapur®) to Yield a Pharmaceutical Product with High Batch-to-Batch Consistency

Recombinant human follicle stimulating hormone (r-hFSH) is widely used for infertility treatment and is subject to the development of biosimilars. There are different purification strategies that can yield r-hFSH of pharmaceutical quality from Chinese hamster ovary cell culture broth. We developed a purification process for r-hFSH centered on immunoaffinity chromatography with single-domain recombinant camelid antibodies. The resulting downstream process is simple and devoid of ultrafiltration operations. Studies on chromatography resin resource and ligand leakage showed that the immunoaffinity matrix employed was suitable for industrial use and stable for at least 40 full chromatography cycles, and the leaked single-domain antibody ligand was completely removed by subsequent purification steps. All chromatography resins employed withstood the same 40 cycles of use without significant changes in separation efficiency and product binding capacity. The resulting industrial purification process yielded batches of r-hFSH with consistent levels of purity and bioactivity.

Current views on N-glycolylneuraminic acid in therapeutic recombinant proteins

The incorporation of the non-human N-glycolylneuraminic acid (Neu5Gc) in therapeutic recombinant proteins raises clinical concerns due to its immunogenic potential and the high prevalence of pre-existing anti-Neu5Gc antibodies in humans. The scientific literature is ambiguous regarding the actual impact of Neu5Gc-containing biotherapeutics as no severe adverse clinical manifestations were unequivocally attributed to Neu5Gc for currently marketed biotherapeutics. This review discusses structural and functional considerations of Neu5Gc-containing glycans regarding the potential impact on drug clearance, their recognition by pre-existing antibodies, and recent hypotheses regarding the tolerance to low Neu5Gc levels. Furthermore, it provides recommendations regarding the standardization of analysis and reporting, analytical aspects relevant for assessing risks associated with Neu5Gc-containing biotherapeutics, and approaches to minimize Neu5Gc incorporation in recombinant protein manufacturing.

Follitropin Delta as a State-of-the-Art Incorporated Companion for Assisted Reproductive Procedures: A Two Year Observational Study

Background and objectives: The latest reports suggest that follitropin delta is a highly efficient recombinant human follicle-stimulating hormone (r-hFSH) that became a part of the current assisted reproductive technologies (ARTs). Therefore, the present study aims to assess a series of parameters (follicles, oocytes, and embryos) and further by the outcomes in women following the administration of follitropin delta. Materials and methods: This observational study included 205 women. They were aged between 21 and 43 years (mean 33.45) and an anti-Müllerian hormone (AMH) level ranging from 0.11 to 16.00 ng/dL (mean 2.89). Results: In accordance with the established methodology and following the centralization of data, a total of fifty-eight pregnancies (28.29%) were achieved; forty-five (36.88%) were achieved in women under 35 years and thirteen (15.66%) in women above 35 years. These figures are positively correlated with women’s age considering that the number of follicles >18 mm, oocytes fertilized and embryo(s) varies among groups. Regarding the interest parameters, we noted n = 1719 follicles > 18 mm, n = 1279 retrieved oocytes, and n = 677 embryos at day 3. On the other hand, the following figures have been registered in women above 35 years: 814–follicles > 18 mm, 612 oocytes retrieved and 301 embryos at day 3. During this study, we registered only three cases of abortions (n = 1–0.81% in women under 35 years and n = 2–2.40% in women above 35 years). Nine pregnancies (7.37%) were stopped from evolution in females under 35 years, and twelve pregnancies (n = 8–6.55% in women under 35 years, while n = 4 in women above 35 years) were unsuccessful. A twin pregnancy has been confirmed (1.20%) in women above 35 years, six ongoing pregnancies (4.91%) in those under 35 years, and two in both groups (one per group–n = 1–0.81%, and 1.20%–n = 1) in which we did not know the exact result were registered at the end of the established studied interval. However, there were also situations in which the treatment cause an over-reactivity or had no effect; n = 2 were non-responders, and n = 1 exhibited moderate ovarian hyperstimulation syndrome (OHSS). Conclusions: Based on our results, we strongly encourage the use of this recombinant gonadotropin on a much larger scale.

Low risk of OHSS with follitropin delta use in women with different polycystic ovary syndrome phenotypes: a retrospective case series

BACKGROUND

To explore the efficacy of follitropin delta in ovarian stimulation of patients with the Rotterdam ESHRE/ASRM 2003 phenotypes of polycystic ovarian syndrome (PCOS) using a retrospective case series with an electronic file search in a reproductive medicine clinic.

CASE PRESENTATION

Seventy-four patients with PCOS undergoing ovarian stimulation according to the individualized dosing algorithm of follitropin delta for in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI)/oocyte freezing were included. Follitropin delta resulted in a high number of pre-ovulatory follicles at the end of stimulation as expected in patients with PCOS. There was a large number of oocytes retrieved with an acceptable percentage of metaphase II (MII) oocytes. There were no cases of moderate or severe OHSS across all phenotypes.

CONCLUSION

Follitropin delta, using the individualized dosing algorithm, appears to be a safe method of ovarian stimulation with a low risk of OHSS in PCOS patients without sacrificing successful stimulation outcomes.

New Human Follitropin Preparations: How Glycan Structural Differences May Affect Biochemical and Biological Function and Clinical Effect

It is well accepted that pituitary follitropin is secreted into the circulation as a mixture of variants, which differ not in primary structure but rather at the level of glycosylation. These glycosidic forms vary in the number of glycosylation sites filled, complexity of glycosidic chains, and sialylation and sulfation. It is generally agreed that high sialylation, 2,3 sialic acid capping of terminal N-acetyl galactosamine or galactose leads to longer circulating half-life, by blocking binding of asialoglycoprotein receptor (ASGPR) in the liver. In contrast, 2,6 sialic acid found in humans does not prevent recognition of galactose and N-acetyl galactosamine by ASGPR. Few studies on clinical outcomes comparing differences in sialylation of follitropin found in commercially available preparations are available. Thus, there is a clear need for a consortium of open data to address this unmet need. Recently, FSH glycosylation, primarily on the β-subunit, which varies as women age, has emerged as a key modifier of follitropin action, with profound biological effects in vivo in animal models. To date, limited information of recombinant follitropin hormone preparations is available. Thus, most of the studies with FSH that is well characterized biochemically have been done in vitro, with engineered non gonadal host cells bearing recombinant receptors or in animal models. Since limited studies in human granulosa cells are available, a question is whether structural differences in glycosylation in commercially available follitropin affects biological function and clinical effect in humans. The presence of fucose, for example, has not been studied greatly even though, in the case of antibody therapy it has been shown to have a large effect on antibody targeting. This review on glycosidic variability of follitropin from the biochemical/structural point of view reflects on this question and presents an assessment in the context of available published data. If clinical differences are to be expected or not, the readers will have a better understanding of the evidence for and limitations of such expectations.

In vitro fertilization cycles stimulated with follitropin delta result in similar embryo development and quality when compared with cycles stimulated with follitropin alfa or follitropin beta

Objective

To study the impact of follitropin delta for ovarian stimulation on embryo development and quality compared with that of follitropin alfa or beta in in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) cycles.

Design

Retrospective cohort study

Setting

University-affiliated, hospital-based fertility clinic

Patient(s)

A total of 403 IVF/ICSI cycles were conducted from September 1, 2018 to December 31, 2019. Cycles were grouped on the basis of stimulation with follitropin delta vs. follitropin alfa or beta.

Intervention(s)

None.

Main Outcome Measure(s)

Embryo parameters and clinical pregnancy and implantation rates.

Result(s)

Ovarian stimulation using follitropin delta resulted in no statistically significant difference in day 3 embryo quality between the control group and follitropin delta group (median 0.50 vs. 0.54 for good quality embryos and median 0.25 vs. 0.20 for intermediate quality embryos). Although on initial analysis there was a lower proportion of good quality blastocysts in the follitropin delta group than in the control group (0.11 vs. 0.22), this difference was no longer present when day 3 after fertilization vitrification and transfer cycles were excluded (0.26 vs. 0.33 follitropin delta vs. control). The clinical pregnancy rates and clinical implantation rates were similar in both groups in fresh transfer cycles.

Conclusion(s)

Stimulation with follitropin delta in IVF/ICSI cycles resulted in similar embryo development and pregnancy rates compared with those of stimulation with follitropin alfa or beta.

Individualized ovarian stimulation for in vitro fertilization: a multicenter, open label, exploratory study with a mixed protocol of follitropin delta and highly purified human menopausal gonadotropin

OBJECTIVE

To evaluate the safety profile and the number of usable blastocysts on day 5 and on day 6 after treatment with an individualized dosing regimen of a follitropin delta and highly purified human menopausal gonadotropin (HP-hMG) for controlled ovarian stimulation.

DESIGN

Multicenter, open label, exploratory study.

SETTING

Reproductive medicine clinics.

PATIENT(S)

A total of 110 patients (aged 18-40 years).

INTERVENTION(S)

Follitropin delta coadministered with HP-hMG, with follitropin delta dose fixed according to an established algorithm and HP-hMG dose at 75 IU when the follitropin delta starting dosage was <12 μg; 150 IU when follitropin delta dosage was 12 μg and weight <100 kg, and 225 IU when follitropin delta dosage was 12 μg and weight ≥100 kg (dosage adjustments confined to HP-hMG only).

MAIN OUTCOME MEASURE(S)

Mean number of good-quality blastocysts obtained at day 5 and day 6 as well as the proportion of women with ovarian hyperstimulation syndrome (OHSS).

RESULT(S)

A cohort study was compared with the follitropin delta group from the Evidence-based Stimulation Trial with Human Recombinant Follicle-Stimulating Hormone in Europe and Rest of World 1 (ESTHER-1) study. Even when stratified by age, a statistically significantly higher mean in the number of oocytes retrieved and number of good-quality blastocysts was observed in this study compared with the ESTHER-1 trial in which follitropin delta was used alone. The rate of patients triggered with a gonadotropin-releasing hormone agonist was statistically significantly higher in our Menopur and Rekovelle Combined Study (MARCS) cohort (43%) when compared with the rates reported in the follitropin delta cohort in the ESTHER-1 study (2.3%). Incidence of any grade of OHSS was 9.3% in the present study compared to 2.6% in follitropin delta group from ESTHER-1 trial. No cases of moderate or severe OHSS were observed in our study compared with 1.4% in the follitropin delta group of ESTHER-1.

CONCLUSION(S)

Optimizing the ovarian response during in vitro fertilization employing a mixed protocol of individualized dosing of follitropin delta and HP-hMG resulted in a statistically significant number of usable blastocysts on days 5 and 6 with an increased risk of mild OHSS, which did not require medical intervention or hospitalization.

CLINICAL TRIAL REGISTRATION NUMBER

NCT03483545.

Prospects for FSH Treatment of Male Infertility

CONTEXT

Despite the new opportunities provided by assisted reproductive technology (ART), male infertility treatment is far from being optimized. One possibility, based on pathophysiological evidence, is to stimulate spermatogenesis with gonadotropins.

EVIDENCE ACQUISITION

We conducted a comprehensive systematic PubMed literature review, up to January 2020, of studies evaluating the genetic basis of follicle-stimulating hormone (FSH) action, the role of FSH in spermatogenesis, and the effects of its administration in male infertility. Manuscripts evaluating the role of genetic polymorphisms and FSH administration in women undergoing ART were considered whenever relevant.

EVIDENCE SYNTHESIS

FSH treatment has been successfully used in hypogonadotropic hypogonadism, but with questionable results in idiopathic male infertility. A limitation of this approach is that treatment plans for male infertility have been borrowed from hypogonadism, without daring to overstimulate, as is done in women undergoing ART. FSH effectiveness depends not only on its serum levels, but also on individual genetic variants able to determine hormonal levels, activity, and receptor response. Single-nucleotide polymorphisms in the follicle-stimulating hormone subunit beta (FSHB) and follicle-stimulating hormone receptor (FSHR) genes have been described, with some of them affecting testicular volume and sperm output. The FSHR p.N680S and the FSHB -211G>T variants could be genetic markers to predict FSH response.

CONCLUSIONS

FSH may be helpful to increase sperm production in infertile men, even if the evidence to recommend the use of FSH in this setting is weak. Placebo-controlled clinical trials, considering the FSHB-FSHR haplotype, are needed to define the most effective dosage, the best treatment length, and the criteria to select candidate responder patients.

Human Recombinant FSH and Its Biosimilars: Clinical Efficacy, Safety, and Cost-Effectiveness in Controlled Ovarian Stimulation for In Vitro Fertilization

Exogenous human follicle-stimulating hormone (hFSH), either derived from extraction and purification from the urine or obtained by recombinant technology in the form of follitropin α, β and δ (rFSH), has been used for decades in the treatment of infertility. The main applications of FSH treatment in the woman have been, and still are, ovulation induction in oligo-anovulatory subjects, and stimulation of the development of a cohort of follicles in patients undergoing controlled ovarian stimulation (COS) for in vitro fertilization (IVF). In the last years, two biosimilars of follitropin alfa, rFSH compounds structurally and functionally similar to the originator, have been approved and marketed for clinical use in Europe. Moreover, some other rFSH biosimilars are currently under investigation. The objective of this article is to review the available evidences comparing the efficacy, safety, and cost-effectiveness of rFSH follitropin alpha originator with its biosimilars, discussing the clinical trials that allowed biosimilars to get registration and marketing authorization.

FSH for the Treatment of Male Infertility

Follicle-stimulating hormone (FSH) supports spermatogenesis acting via its receptor (FSHR), which activates trophic effects in gonadal Sertoli cells. These pathways are targeted by hormonal drugs used for clinical treatment of infertile men, mainly belonging to sub-groups defined as hypogonadotropic hypogonadism or idiopathic infertility. While, in the first case, fertility may be efficiently restored by specific treatments, such as pulsatile gonadotropin releasing hormone (GnRH) or choriogonadotropin (hCG) alone or in combination with FSH, less is known about the efficacy of FSH in supporting the treatment of male idiopathic infertility. This review focuses on the role of FSH in the clinical approach to male reproduction, addressing the state-of-the-art from the little data available and discussing the pharmacological evidence. New compounds, such as allosteric ligands, dually active, chimeric gonadotropins and immunoglobulins, may represent interesting avenues for future personalized, pharmacological approaches to male infertility.

The Development of Gonadotropins for Clinical Use in the Treatment of Infertility

The first commercially available gonadotropin product was a human chorionic gonadotropin (hCG) extract, followed by animal pituitary gonadotropin extracts. These extracts were effective, leading to the introduction of the two-step protocol, which involved ovarian stimulation using animal gonadotropins followed by ovulation triggering using hCG. However, ovarian response to animal gonadotropins was maintained for only a short period of time due to immune recognition. This prompted the development of human pituitary gonadotropins; however, supply problems, the risk for Creutzfeld-Jakob disease, and the advent of recombinant technology eventually led to the withdrawal of human pituitary gonadotropin from the market. Urinary human menopausal gonadotropin (hMG) preparations were also produced, with subsequent improvements in purification techniques enabling development of products with standardized proportions of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) activity. In 1962 the first reported pregnancy following ovulation stimulation with hMG and ovulation induction with hCG was described, and this product was later established as part of the standard protocol for ART. Improvements in immunopurification techniques enabled the removal of LH from hMG preparations; however, unidentified urinary protein contaminants remained a problem. Subsequently, monoclonal FSH antibodies were used to produce a highly purified FSH preparation containing <0.1 IU of LH activity and <5% unidentified urinary proteins, enabling the formulation of smaller injection volumes that could be administered subcutaneously rather than intramuscularly. Ongoing issues with gonadotropins derived from urine donations, including batch-to-batch variability and a finite donor supply, were overcome by the development of recombinant gonadotropin products. The first recombinant human FSH molecules received marketing approvals in 1995 (follitropin alfa) and 1996 (follitropin beta). These had superior purity and a more homogenous glycosylation pattern compared with urinary or pituitary FSH. Subsequently recombinant versions of LH and hCG have been developed, and biosimilar versions of follitropin alfa have received marketing authorization. More recent developments include a recombinant FSH produced using a human cell line, and a long-acting FSH preparation. These state of the art products are administered subcutaneously via pen injection devices.

Modulation of Gonadotropins Activity by Antibodies

Gonadotropins are essential for reproduction control in humans as well as in animals. They are widely used all over the world for ovarian stimulation in women, spermatogenesis stimulation in men, and ovulation induction and superovulation in animals. Despite the availability of many different preparations, all are made of the native hormones. Having different ligands with a wide activity range for a given receptor helps better understand its molecular and cellular signaling mechanisms as well as its physiological functions, and thus helps the development of more specific and adapted medicines. One way to control the gonadotropins' activity could be the use of modulating antibodies. Antibodies are powerful tools that were largely used to decipher gonadotropins' actions and they have shown their utility as therapeutics in several other indications such as cancer. In this review, we summarize the inhibitory and potentiating antibodies to gonadotropins, and their potential therapeutic applications.

Structure-Function Relationships of the Follicle-Stimulating Hormone Receptor

The follicle-stimulating hormone receptor (FSHR) plays a crucial role in reproduction. This structurally complex receptor is a member of the G-protein coupled receptor (GPCR) superfamily of membrane receptors. As with the other structurally similar glycoprotein hormone receptors (the thyroid-stimulating hormone and luteinizing hormone-chorionic gonadotropin hormone receptors), the FSHR is characterized by an extensive extracellular domain, where binding to FSH occurs, linked to the signal specificity subdomain or hinge region. This region is involved in ligand-stimulated receptor activation whereas the seven transmembrane domain is associated with receptor activation and transmission of the activation process to the intracellular loops comprised of amino acid sequences, which predicate coupling to effectors, interaction with adapter proteins, and triggering of downstream intracellular signaling. In this review, we describe the most important structural features of the FSHR intimately involved in regulation of FSHR function, including trafficking, dimerization, and oligomerization, ligand binding, agonist-stimulated activation, and signal transduction.