Biosimilar FSH preparations- are they identical twins or just siblings?

The influence of the pharmaceutical industry on the development of gonadotrophins and ovarian stimulation protocols in assisted reproductive technologies

Introduction

This review examines the evolution of gonadotrophins in ovarian stimulation (OS) protocols for assisted reproductive techniques (ART). Since the advent of in vitro fertilisation (IVF) in the late 1970s, the pharmaceutical industry has played a pivotal role in advancing gonadotrophin production, improving drug purity and optimising delivery methods. Despite significant progress, questions remain about the robustness of the evidence supporting the use of different gonadotrophins and the impact of industry-driven research on clinical practice. The review critically examines the evolution, evidence and future directions of gonadotrophin use in ART.

Methods

A comprehensive literature search was carried out in multiple databases to select articles/reviews on historical developments, manufacturing and analytical techniques, regulatory frameworks and clinical trials undertaken to assess gonadotrophin production, formulation processes and their integration into clinical practice. The analysis included mainly evidence from pharmaceutical sponsored randomised controlled trials (RCTs) as well as single arm, registration or post approval studies. Studies on new molecular entities were reviewed. Systematic reviews and meta-analyses, national registries were consulted. Laboratory developments, regulatory challenges, economic constraints, were considered.

Results

Over the past four decades, ART has seen remarkable improvements, including increased live birth rates in women of advanced ovarian age, reduced multiple births, and the advent of patient-friendly pen devices. Innovations such as recombinant FSH (rFSH) and biosimilars have expanded treatment options. However, the high cost of drug development as well as the complexity of the ART process have contributed to underpowered trials and reliance on meta-analyses, which often fail to account for confounding factors.

Discussion

While gonadotrophins have been shown to be effective for OS, unresolved issues, such as the role of supplementing LH activity in OS protocols, highlight the need for more robust trials. Collaboration between stakeholders is essential to standardise trial designs, define key outcomes and minimise bias. Emerging technologies, including AI and genetic testing, offer opportunities to refine embryo assessment and implantation outcomes, thus improving trial design. A renewed focus on rigorous, transparent trials and interdisciplinary collaboration is essential to advance patient care and address unmet challenges in ART treatment. Beyond gonadotrophins, alternative therapeutic avenues to improve oocyte competence and implantation success warrant exploration.

The effect of gonadotropin gap for non-growing follicles in poor ovarian response: Might this be a new strategy?

Objective

Cessation of gonadotropin stimulation might affect follicular growth in patients in POSEIDON groups 3 and 4, which are unresponsive to high-dose stimulation.

Materials and Methods

In this retrospective study, data were extracted from the medical records of patients treated at the Acıbadem Maslak Hospital Assisted Reproductive Technologies Unit between November 2010 and December 2020. Eighty-five patients who fulfilled the inclusion criteria were included in the study. Gonadotropin stimulation was discontinued if the follicle diameter increased by 2 mm within 7 days after the initiation of stimulation in patients in groups 3 and 4. The outcomes of the treatment strategy and pregnancy were recorded.

Results

Follicular growth was observed in 40% (34/85) of patients, of whom 52.9% (18/34) had 2pn embryos. Ten of the 85 patients (11.8%) underwent embryo transfer, resulting in biochemical pregnancy for two patients and healthy live birth for one patient.

Conclusion

When high-dose stimulation is ineffective, discontinuing gonadotropin administration during ovarian stimulation may provide patients with the opportunity to conceive using their own biological oocytes. To the best of our knowledge, this is the first study to report a live birth rate using this strategy.

Follicle-Stimulating Hormone Sweetness: How Carbohydrate Structures Impact on the Biological Function of the Hormone

Follicle-stimulating hormone (FSH), or follitropin, exists in multiple molecular forms due largely to its protein-carbohydrate composition and the complexity of the glycans attached to the protein core. The heterogeneity of gonadotropins exists in two forms, macroheterogeneity, which results from the absence of one or two oligosaccharide chains in the ß-subunit, and microheterogeneity which results from variation in the structures and complexity of the glycans attached to the hormone. In the clinical arena, FSH compounds are widely used by fertility specialists to promote ovarian follicle growth and maturation to a preovulatory follicle containing a fertilization-competent oocyte. Several genetically engineered recombinant human FSH preparations have been added to the arsenal of follitropin preparations in several countries for the treatment of infertility, particularly in women attending assisted reproduction clinics. Although the primary structure of these recombinant proteins is identical to that of naturally occurring FSH, the cell context and variations in the production and purification processes may impact the glycosidic profile of the recombinant FSH macro- and micro-heterogeneity, which may potentially influence the pharmacokinetics and pharmacodynamics of the compound. This review concentrates on the structure-function correlates of follitropin, with emphasis on the physiological and biological importance of the carbohydrates attached to its protein core, including its pharmacokinetics and biological activity. Emphasis is placed on pituitary FSH, and the available data on the various recombinant FSH preparations employed in therapeutics are also discussed, considering that this gonadotropin represents the cornerstone for the treatment of infertility in modern assisted reproduction.

A Cost-Effectiveness Analysis of Gonadotropins Used for Ovarian Stimulation during Assisted Reproductive Technology Based on Data from the French Nationwide Claims Database (SNDS)

OBJECTIVE

Various gonadotropins are used for ovarian stimulation (OS). This study investigated the cost-effectiveness of different gonadotropins based on real-world data from the French National Health Database (SNDS) over a 7-year follow-up of assisted reproductive technology (ART) treatments.

DESIGN

Cost-effectiveness analysis of different gonadotropins based on real-world data from the SNDS was conducted.

PARTICIPANTS

Women from SNDS undergoing OS leading to oocyte pick-up registered between January 31, 2013, and December 31, 2018 (N = 245,534 stimulations), and receiving either recombinant human follicle stimulating hormone (r-hFSH alfa originator; 110,439), its biosimilars (12,287), or urinaries (mainly highly purified human menopausal gonadotropin [HP-hMG; 65,654] and marginally highly purified urinary-human follicle stimulating hormone [7,821]) were included (follow-up: December 31, 2019).

SETTINGS AND METHODS

Clinical inputs for this model, including live birth (LB) and cumulative LB (CLB) were calculated from data as published in [Best Pract Res Clin Obstet Gynaecol. 2023;88:102308]. A decision-tree model was developed comprising pregnancy and live birth rate (LBR) states for a complete ART cycle, including one fresh and ≤4 frozen/thawed embryo transfers and related costs. Cost inputs included those of drugs, ART procedure, pregnancy and delivery, and adverse events. Cost per LB and CLB and incremental cost-effectiveness ratio (ICER) were assessed. Robustness of results was determined by comprehensive sensitivity analyses.

RESULTS

Overall, r-hFSH alfa originator was found to be associated with a lower cost per LB and per CLB (cost per LB: EUR 26,010; CLB: EUR 22,278) versus its biosimilars (cost per LB: EUR 28,037; CLB: EUR 23,807) and versus urinaries (cost per LB: EUR 26,636; CLB: EUR 23,335). Calculated ICERs with r-hFSH alfa for LB were EUR 5,538 and EUR 14,090, whereas for CLB were EUR 1,945 and EUR 13,742 versus biosimilars and urinaries, respectively. Cost-effectiveness acceptability curve showed that in a majority of iterations, r-hFSH alfa originator had a probability of being cost-effective at a hypothetical threshold of EUR 20,000/LB. Sensitivity analyses showed that the most important variable impacting the outcome in fresh transfers was the probability of birth for biosimilars and the probability of pregnancy for urinaries, while for cumulative transfers, it was the probability of pregnancy for biosimilars and the probability of birth for urinaries.

LIMITATIONS

As the clinical data were obtained from a non-interventional study and not a randomized controlled trial, the results may still be susceptible to residual confounding or other biases.

CONCLUSIONS

r-hFSH alfa originator is cost-effective compared to its biosimilars and to urinaries (mainly HP-hMG) and is associated with a lower cost per LB compared to these gonadotropins, where the main driver is the higher LB efficacy rate achieved with it.

Clinical outcomes of three follitropin alfa preparations for ovarian stimulation using an oral micronized progesterone-primed protocol in an oocyte donation program

Introduction

This large multicenter study aimed to evaluate clinical outcomes using three follitropin alfa preparations within a progestin-primed ovarian stimulation (PPOS) protocol, while identifying contributing factors to cycle success.

Methods

A retrospective, anonymized cohort analysis was conducted on donor-recipient cycles from 12 clinics during 2019 to 2021. 7389 oocyte donors underwent ovarian stimulation (OS) with three follitropin alfa preparations (Ovaleap® [n=3231], Bemfola® [n=3542], Gonal-F® [n=616]) were included. Stimulation began on cycle days 2 or 3 with daily administration of 150-225 IU follitropin alfa. 10 mg medroxyprogesterone acetate (MPA) was administered daily until GnRH agonist trigger using a single dose of 0.2mg GnRH agonist for final follicular maturation. Statistical analysis included ANOVA, Chi-squared, and logistic regression.

Results

Whilst there were some differences in patient and stimulation characteristics, including donor age and number of retrieved oocytes, clinical variables did not significantly differ among the three study groups. Linear regression revealed donor age [0.986 (0.974-0.999)] and number of mature oocytes [1.027 (1.007-1.047)] significantly impacted ongoing pregnancy rates, while the type of follitropin alfa [1.048 (0.956-1.149)] used did not. No significant differences were observed in the cumulative live birth rate (CLBR) among oocytes obtained from stimulation with Bemfola (64.9%), Gonal-F (64.1%) and Ovaleap (66.1%), p= 0.385.

Discussion

This study demonstrated comparable clinical outcomes and CLBR between biosimilars and the reference product of follitropin alfa within PPOS protocols, hence they are interchangeable in a real-world patient setting.

Follitropin Alpha versus Follitropin Beta in IVF/ICSI Cycle: A Retrospective Cohort Study

Purpose

The purpose of this study was to compare the efficacy of Follitropin alpha (Gonal-F) and Follitropin beta (Puregon) on cumulative live birth rate (CLBR), defined as the percentage of the number of patients who delivered for the first time in a single ovarian stimulation cycle and the number of patients in all oocyte retrieval cycles.

Methods

A retrospective cohort study including 2864 infertile patients who underwent ovarian stimulation with Puregon (group A, n=1313) and Gonal-F (group B, n=1551) was conducted between July 2015 and June 2021 at a university-affiliated reproductive medicine center. Reduce potential confounding factors between groups, propensity scores and multivariable logistic regression analyses were estimated to obtain unbiased estimates of outcomes. The primary outcome was the difference in CLBR between the two groups.

Results

Each group identified 1160 individuals after propensity score matching (PSM). Baseline characteristics were similar between groups after PSM. The total gonadotrophin (Gn) dose (2400 vs 2325), p=0.038) and cost of Gn usage (5327.9¥ vs 7547.2¥, p<0.001) between the Puregon and Gonal-F groups were statistically significant. Nevertheless, the pregnancy outcomes between the two groups were comparable after fresh embryo transfer and subsequent frozen-thawed embryo transfer. Additionally, there was also no difference observed in the primary outcome of CLBR (52.8% vs 55.7%, p=0.169). Multivariable regression analysis revealed that the type of Gn was not associated with CLBR (p = 0.912).

Conclusion

Gonal-F may be a reasonable option for infertile patients who are hesitant to receive more Gn dosage injections. Furthermore, Puregon can eliminate unneeded anxiety and expenses while also administering more flexibility. Taken together, these findings could well be utilized in everyday clinical practice to better inform patients when deciding on an ovarian stimulation strategy.

An updated meta-analysis comparing the efficacy and safety of biosimilar medicinal products to the original follitropin alfa

INTRODUCTION

The aim of this study was to provide an updated meta-analysis assessing the therapeutic equivalence between follitropin alfa biosimilars and the reference medication in women undergoing assisted reproductive technologies (ART).

EVIDENCE ACQUISITION

The studies included in the analysis were pooled together in order to estimate the log odds ratio (OR) for binary outcomes and the mean difference (MD) for continuous outcomes along with the corresponding 95% confidence intervals (CI) by using a random effects model. The heterogeneity between the studies was evaluated with the Higgins and χ2 tests.

EVIDENCE SYNTHESIS

No differences were found concerning the number of oocytes retrieved at ovum pick-up, the primary endpoint recommended by the European Medicines Agency (EMA) (MD -0.04 CI [-0.78, 0.71], P=0.92). A significantly higher clinical pregnancy rate (OR 0.70 CI [0.53, 0.93], P=0.01) was observed in the reference product group in comparison to the biosimilar follitropin alfa, whereas no statistically significant differences were found for biochemical pregnancy rate, take home baby rate, total follitropin alfa dose, duration of stimulation, and ovarian hyperstimulation syndrome risk.

CONCLUSIONS

The non-inferiority of biosimilar formulations in comparison to the reference product, with respect to number of oocytes retrieved at ovum pick-up, was shown.

Comparative effectiveness of gonadotropins used for ovarian stimulation during assisted reproductive technologies (ART) in France: A real-world observational study from the French nationwide claims database (SNDS)

This comparative non-interventional study using data from the French National Health Database (Système National des Données de Santé) investigated real-world (cumulative) live birth outcomes following ovarian stimulation, leading to oocyte pickup with either originator recombinant human follicle-stimulating hormone (r-hFSH) products (alfa or beta), r-hFSH alfa biosimilars, or urinaries including mainly HP-hMG (menotropins), and marginally u-hFSH-HP (urofollitropin). Using data from 245,534 stimulations (153,600 women), biosimilars resulted in a 19% lower live birth (adjusted odds ratio (OR) 0.81, 95% confidence interval (CI) 0.76-0.86) and a 14% lower cumulative live birth (adjusted hazard ratio (HR) 0.86, 95% CI 0.82-0.89); and urinaries resulted in a 7% lower live birth (adjusted OR 0.93, 95% CI 0.90-0.96) and an 11% lower cumulative live birth (adjusted HR 0.89, 95% CI 0.87-0.91) versus originator r-hFSH alfa. Results were consistent across strata (age and ART strategy), sensitivity analysis using propensity score matching, and with r-hFSH alfa and beta as the reference group.

Comparative Assessment of the Structural Features of Originator Recombinant Human Follitropin Alfa Versus Recombinant Human Follitropin Alfa Biosimilar Preparations Approved in Non-European Regions

Although the full primary structures of the alfa and beta subunits of reference r-hFSH-alfa and its biosimilars are identical, cell context-dependent differences in the expressing cell lines and manufacturing process can lead to variations in glycosylation profiles. In the present study, we compared the structural features of reference r-hFSH-alfa with those of five biosimilar preparations approved in different global regions outside Europe (Primapur^®, Jin Sai Heng^®, Follitrope^®, Folisurge^®, and Corneumon^®) with respect to glycosylation, macro- and microheterogeneity, and other post-translational modifications and higher order structure. The mean proportion of N-glycosylation-site occupancy was highest in reference r-hFSH-alfa, decreasing sequentially in Primapur, Jin Sai Heng, Corneumon, Follisurge and Follitrope, respectively. The level of antennarity showed slightly higher complexity in Corneumon, Primapur and Follitrope versus reference r-hFSH-alfa, whereas Jin Sai Heng and Folisurge were aligned with reference r-hFSH-alfa across all N-glycosylation sites. Sialylation level was higher in Corneumon and Follitrope, but small differences were detected in other biosimilar preparations compared with reference r-hFSH-alfa. Jin Sai Heng showed higher levels of N-glyconeuramic acid than the other preparations. Minor differences in oxidation levels were seen among the different products. Therefore, in summary, we identified var ious differences in N-glycosylation occupancy, antennarity, sialylation and oxidation between reference r-hFSH-alfa and the biosimilar preparations analyzed.

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.

Efficacy and safety of follitropin alpha biosimilars compared to their reference product: a Meta-analysis

AIM

Recently published multicentre, randomized phase III studies suggested the therapeutic equivalence of biosimilar follitropin alpha medicaments compared to the reference product. The aim of this meta-analysis is to pool the results of the three phase III trials in order to provide an overall analysis about the clinical bioequivalence between biosimilars and the originator.

METHODS

The studies included in the analysis were pooled together in order to estimate the log odds ratio (OR) for binary outcomes and the weighted mean difference (WMD) for continuous outcomes along with the corresponding 95% confidence intervals (CI) by using a random effects model. The heterogeneity between the studies was evaluated with the Higgins and Chi-square tests.

RESULTS

No differences were found in term of number of oocytes retrieved at ovum pick-up, the primary endpoint recommended by the European Medicines Agency. No statistical differences were also found for biochemical pregnancy rate, take home baby rate, total follitropin alpha dose, duration of stimulation, and OHSS risk. A significantly higher clinical pregnancy rate (p = .03) was observed in the originator group in comparison to the biosimilar follitropin alpha.

CONCLUSION

Biosimilar follitropin alpha medicaments resulted comparable in comparison to the reference product with respect to the number of oocytes retrieved, that is the primary endpoint recommended by the European Medicines Agency .Further study is needed to evaluate the therapeutic bioequivalence between follitropin alpha biosimilar and the reference medication with respect to secondary endpoints.

Biosimilar recombinant follitropin alfa preparations versus the reference product (Gonal-F®) in couples undergoing assisted reproductive technology treatment: a systematic review and meta-analysis

BACKGROUND

Live birth has increasingly been identified as the standard clinical approach to measure the success of medically assisted reproduction (MAR). However, previous analyses comparing biosimilar preparations of follitropin alfa versus the reference product (GONAL-f®, Merck KGaA, Darmstadt, Germany or GONAL-f® RFF; EMD Serono, Inc., Rockland, MA), have had insufficient power to detect differences in clinically meaningful outcomes such as live birth.

METHODS

Medline, Embase, the Cochrane Library, Web of Science and clinical trial registries were searched for randomised controlled trials (RCTs) and conference abstracts comparing biosimilar follitropin alfa versus the reference product in controlled ovarian stimulation (COS) cycles published before 31 October 2020. Only studies in humans and publications in English were included. Retrieved studies were screened independently by two authors based on titles and abstracts, and then by full text.

INCLUSION CRITERIA

RCTs comparing follitropin alfa biosimilar preparations with the reference product in infertile patients of any age, with any type of infertility for any duration, undergoing COS for the purposes of MAR treatment (including frozen cycles). The primary outcome was live birth. Combined data for biosimilar preparations were analysed using a fixed-effects model.

RESULTS

From 292 unique records identified, 17 studies were included in the systematic review, representing five unique RCTs that were included in the meta-analysis. Rates of live birth (RR = 0.83, 95% CI 0.71, 0.97; 4 RCTs, n = 1881, I² = 0%), clinical pregnancy (RR = 0.82, 95% CI 0.72, 0.94; 4 RCTs, n = 2222, I² = 0%) and ongoing pregnancy (RR = 0.81, 95% CI 0.68, 0.96; 4 RCTs, n = 1232, I² = 0%) were significantly lower with biosimilar preparations versus the reference product. Rates of cumulative live birth and cumulative clinical pregnancy were also significantly lower with biosimilars versus the reference product. There was high risk of publication bias.

CONCLUSIONS

This meta-analysis included data from RCTs evaluating the efficacy and safety of the biosimilar follitropin alfa preparations and demonstrated lower probability of live birth and pregnancy (ongoing and clinical) in couples treated with biosimilar preparations compared with the reference product. This study provides more insight into the differences between biosimilar r-hFSH preparations and the reference product than previously reported.

TRIAL REGISTRATION

Registration number: CRD42019121992 .

Rate of rebound in follicle growth after cessation of ovarian stimulation in initial non-responders: a prospective cohort study

Previously anecdotally observed rebounds in follicle growth after interruption of exogenous gonadotropins in absolute non-responders were the impetus for here reported study. In a prospective cohort study, we investigated 49 consecutive patients, absolutely unresponsive to maximal exogenous gonadotropin stimulation, for a so-called rebound response to ovarian stimulation. A rebound response was defined as follicle growth following complete withdrawal of exogenous gonadotropin stimulation after complete failure to respond to maximal gonadotropin stimulation over up to 5–7 days. Median age of study patients was 40.5 ± 5.1 years (range 23–52). Women with and without rebound did not differ significantly (40.0 ± 6.0 vs. 41.0 ± 7.0 years, P = 0.41), with 24 (49.0%) recording a rebound and 25 (51.0%) not. Among the former, 21 (87.5%) reached retrieval of 1–3 oocytes and 15 (30.6%) reached embryo transfer. A successful rebound in almost half of prior non-responders was an unsuspected response rate, as was retrieval of 1–3 oocytes in over half of rebounding patients. Attempting rebounds may, thus, represent another incremental step in very poor prognosis patients before giving up on utilization of autologous oocytes. Here presented findings support further investigations into the underlying physiology leading to such an unexpectedly high rebound rate.

Optimising Follicular Development, Pituitary Suppression, Triggering and Luteal Phase Support During Assisted Reproductive Technology: A Delphi Consensus

BACKGROUND

A Delphi consensus was conducted to evaluate global expert opinions on key aspects of assisted reproductive technology (ART) treatment.

METHODS

Ten experts plus the Scientific Coordinator discussed and amended statements plus supporting references proposed by the Scientific Coordinator. The statements were distributed via an online survey to 35 experts, who voted on their level of agreement or disagreement with each statement. Consensus was reached if the proportion of participants agreeing or disagreeing with a statement was >66%.

RESULTS

Eighteen statements were developed. All statements reached consensus and the most relevant are summarised here. (1) Follicular development and stimulation with gonadotropins (n = 9 statements): Recombinant human follicle stimulating hormone (r-hFSH) alone is sufficient for follicular development in normogonadotropic patients aged <35 years. Oocyte number and live birth rate are strongly correlated; there is a positive linear correlation with cumulative live birth rate. Different r-hFSH preparations have identical polypeptide chains but different glycosylation patterns, affecting the biospecific activity of r-hFSH. r-hFSH plus recombinant human LH (r-hFSH:r-hLH) demonstrates improved pregnancy rates and cost efficacy versus human menopausal gonadotropin (hMG) in patients with severe FSH and LH deficiency. (2) Pituitary suppression (n = 2 statements): Gonadotropin releasing hormone (GnRH) antagonists are associated with lower rates of any grade ovarian hyperstimulation syndrome (OHSS) and cycle cancellation versus GnRH agonists. (3) Final oocyte maturation triggering (n=4 statements): Human chorionic gonadotropin (hCG) represents the gold standard in fresh cycles. The efficacy of hCG triggering for frozen transfers in modified natural cycles is controversial compared with LH peak monitoring. Current evidence supports significantly higher pregnancy rates with hCG + GnRH agonist versus hCG alone, but further evidence is needed. GnRH agonist trigger, in GnRH antagonist protocol, is recommended for final oocyte maturation in women at risk of OHSS. (4) Luteal-phase support (n = 3 statements): Vaginal progesterone therapy represents the gold standard for luteal-phase support.

CONCLUSIONS

This Delphi consensus provides a real-world clinical perspective on the specific approaches during the key steps of ART treatment from a diverse group of international experts. Additional guidance from clinicians on ART strategies could complement guidelines and policies, and may help to further improve treatment outcomes.

Retrospective analysis of the use of two recombinant follitropin alfa injections in patients undergoing in vitro fertilization treatment with the gonadotropin-releasing hormone antagonist protocol

AIM

To evaluate the clinical efficacy of biosimilar (Ovaleap) compared with the referenced follitropin alfa (Gonal-f), within the context of antagonistic multiple doses protocol of controlled ovarian hyperstimulation (COH) for in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) techniques.

METHODS

A retrospective, monocentric study included 229 infertile women aged 22 to 43 years who underwent their first cycle of COH for the purpose of the IVF or ICSI during the period of 2017. Eligible patients underwent ovarian stimulation with either Ovaleap (n = 152) or Gonal-f (n = 77) starting at Cycle Day 2 and were receiving gonadotropin-releasing hormone (GnRH) antagonist in either fixed or flexible antagonist protocol manner.

RESULTS

Ovaleap-treatment resulted in fewer number of oocytes retrieved in regard to Gonal-f-treatment, with the median of seven oocytes retrieved in the Ovaleap group versus nine in the Gonal-f group (U = 5369.5, P = 0.3079). Clinical pregnancy rate was 24.3% in the overall study sample and 31.9% in women with embryo transfer, in the Ovaleap group. Similarly, in the Gonal-f group these rates were 25.0% and 34.5%, respectively. Only four patients experienced ovarian hyperstimulation syndrome, with one case in Ovaleap-treatment group and three cases in Gonal-f-treatment group.

CONCLUSION

While the clinical efficacy profile favored using Gonal-f formulation of follitropin alfa, this analysis showed that there is no significant difference in the number of oocytes retrieved between Ovaleap and Gonal-f follitropin alfa formulations, used within GnRH antagonist protocols of COH.

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.

A multicenter, randomized, phase III study comparing the efficacy and safety of follitropin alpha biosimilar and the original follitropin alpha

OBJECTIVE

The aim of the present study was to investigate the therapeutic equivalence between the follitropin alpha biosimilar and the reference medication in women undergoing assisted reproductive technologies (ART).

STUDY DESIGN

This multicenter, randomized (1:1), embryologist-blinded, parallel-group, comparative phase III study involved 110 women aged 20-35 years old with tubal and/or male factors of infertility. All of the subjects underwent controlled ovarian hyperstimulation (COH) using a gonadotropin-releasing hormone antagonist (GnRH-ant) protocol. Over the 5-day fixed-dose regimen, the women received 150 IU/day of follitropin alpha biosimilar (n = 55) or original follitropin alpha (n = 55), followed by dose adaptation. The primary endpoint for assessing the therapeutic equivalence was the number of retrieved oocytes using a pre-determined clinical equivalence margin of ± 3.4 oocytes.

RESULTS

Similar numbers of oocytes were retrieved in both groups: 12.16 ± 7.28 in the follitropin alpha biosimilar group and 11.62 ± 6.29 in the original follitropin alpha group, with mean difference of 0.546 ± 1.297 oocytes (95% confidence interval [CI]: -2.026, 3.116), p = 0.002 (intention-to-treat [ITT] population). Additionally, no statistically significant differences were found for secondary endpoints: the onset of biochemical (34.7% and 36.7%, p = 0.883), clinical pregnancy (26.5% and 32.7%, p = 0.507), delivery (26.5% and 24.5%, p = 0.817) and take-home baby rate (28.6% and 26.5%, p = 0.816) for the follitropin biosimilar and original follitropin groups (per-protocol [PP] population). Ovarian hyperstimulation syndrome was observed in subjects with a positive pregnancy test in 0% and 3.64% of cases and after triggering ovulation in 7.27% and 3.64% for the follitropin biosimilar and original follitropin groups, respectively.

CONCLUSIONS

This study demonstrated similar therapeutic equivalence and safety profiles between the follitropin alpha biosimilar and the reference follitropin in women who underwent COH in GnRH-ant cycles.

TRIAL REGISTRATION NUMBER

1. Name of the registry: ClinicalTrials.gov.

TRIAL REGISTRATION NUMBER

NCT03088137. Date of registration: 02.03.2017, retrospectively registered. Trial conducted between 08.02.2017 and 17.08.2018, the date of enrollment of the first participant - 08.02.2017. 2. Name of the registry: Russian Ministry of Health, grls.rosminzdrav.ru.

TRIAL REGISTRATION NUMBER

RCT 754. Date of registration: 26.10.2016, prospectively registered.

High-level expression of biologically active human follicle stimulating hormone in the Chinese hamster ovary cell line by a pair of tricistronic and monocistronic vectors

Recombinant human follicle stimulating hormone (FSH), produced in Chinese hamster ovary (CHO) cells, is widely used for treatment of fertility disorders and is subject to biosimilars development. Cell lines with high specific productivities may simplify the FSH production process. Here, we used our previously established expression system based on vector p1.1 to create new cell lines secreting heterodimeric FSH protein. To this end, we linked open reading frames of both FSH subunits by the wild-type internal ribosome entry site from the encephalomyocarditis virus (EMCV IRES). Intact and double-negative for the dihydrofolate reductase CHO cells were stably transfected by the FSH-coding plasmids. Stably transfected intact cells showed higher level of the FSH secretion and were utilized for subsequent methotrexate-driven transgene amplification, which doubled their productivity. The excess of the free α-subunit was corrected by transfecting the cells by the additional p1.1-based plasmid encoding the β-subunit of the FSH. Clonal cell lines obtained secreted mostly the heterodimeric FSH and possessed specific productivities up to 12.3±1.7 pg/cell/day. Candidate clonal cell line C-P1.3-FSH-G4 maintained a constant specific productivity for at least 2 months of culturing without the section pressure. The resulting FSH protein conformed to the international pharmaceutical quality criteria as evidenced by the receptor binding kinetics, distribution pattern of hormone isoforms and biological activity. In conclusion, our expression system offers a simple and cost-effective approach to production of FSH.

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.

Safety concerns of biosimilar hormone products

BACKGROUND

Currently, biotherapeutic medicines are the most effective options for the treatment of many severe and chronic diseases. For faster market entry of biotherapeutic products and their cost reduction, the principles of "biosimilarity" have been developed. Development and licensing of biosimilars is allowed only after the end of patent exclusivity of the original preparation period.

PURPOSE

Characteristics of the main safety parameters of biosimilar hormone preparations licensed by EMA.

METHODS

This paper analyzes the results demonstrating the similarities and differences between biosimilar and reference hormone products indicated in the EPAR (public assessment report) for the examination of materials presented for the licensing of biosimilar products.

RESULTS

During the development of biosimilar hormone medicines, differences in the glycosylation profile between biosimilar and reference preparations are revealed. As biotherapeutical preparations are produced by cells, the differences in glycosylation profile between biosimilar and referent preparation are predictable. While carrying out clinical studies, a high similarity of biosimilar and reference product effectiveness is shown, but some differences between them in the safety profile are revealed.

CONCLUSIONS

The study of biosimilar product safety has shown the necessity of further improvement in safety and standard approaches for the assessment of the immunogenicity of biosimilar products.

In vitro fertilisation/intracytoplasmic sperm injection beyond 2020

Over 8 million babies have been born following IVF (in vitro fertilisation) and other artificial reproductive technology (ART) procedures since Louise Brown's birth 40 years ago. New innovations have added much complexity to both clinical and laboratory procedures over the last four decades. Translation of novel approaches from basic science into clinical practice continues unabated, widening the applicability of ART to new groups of people and helping improve both chances of healthy live birth and patient acceptability. However, the impact of ART on the health of both patients and their offspring continues to cause concern, and many ethical challenges created by new scientific developments in this field attract widely differing opinions. What is undeniable is that there will be a sustained global growth in utilisation of ART and that reproductive tourism will allow many people to access the treatment they desire notwithstanding national regulations that may forbid some approaches. The greatest challenge is to expand access to ART to those living in the less wealthy nations who are equally deserving of its benefits.

Glycosylation Pattern and in vitro Bioactivity of Reference Follitropin alfa and Biosimilars

Recombinant follicle-stimulating hormone (FSH) (follitropin alfa) and biosimilar preparations are available for clinical use. They have specific FSH activity and a unique glycosylation profile dependent on source cells. The aim of the study is to compare the originator (reference) follitropin alfa (Gonal-f®)- with biosimilar preparations (Bemfola® and Ovaleap®)-induced cellular responses in vitro. Gonadotropin N-glycosylation profiles were analyzed by ELISA lectin assay, revealing preparation specific-patterns of glycan species (Kruskal-Wallis test; p < 0.05, n = 6) and by glycotope mapping. Increasing concentrations of Gonal-f® or biosimilar (1 × 10^-3-1 × 10³ ng/ml) were used for treating human primary granulosa lutein cells (hGLC) and FSH receptor (FSHR)-transfected HEK293 cells in vitro. Intracellular cAMP production, Ca²⁺ increase and β-arrestin 2 recruitment were evaluated by BRET, CREB, and ERK1/2 phosphorylation by Western blotting. 12-h gene expression, and 8- and 24-h progesterone and estradiol synthesis were measured by real-time PCR and immunoassay, respectively. We found preparation-specific glycosylation patterns by lectin assay (Kruskal-Wallis test; p < 0.001; n = 6), and similar cAMP production and β-arrestin 2 recruitment in FSHR-transfected HEK293 cells (cAMP EC₅₀ range = 12 ± 0.9-24 ± 1.7 ng/ml; β-arrestin 2 EC₅₀ range = 140 ± 14.1-313 ± 18.7 ng/ml; Kruskal-Wallis test; p ≥ 0.05; n = 4). Kinetics analysis revealed that intracellular Ca²⁺ increased upon cell treatment by 4 μg/ml Gonal-f®, while equal concentrations of biosimilars failed to induced a response (Kruskal-Wallis test; p < 0.05; n = 3). All preparations induced both 8 and 24 h-progesterone and estradiol synthesis in hGLC, while no different EC₅₀s were demonstrated (Kruskal-Wallis test; p > 0.05; n = 5). Apart from preparation-specific intracellular Ca²⁺ increases achieved at supra-physiological hormone doses, all compounds induced similar intracellular responses and steroidogenesis, reflecting similar bioactivity, and overall structural homogeneity.

Comparative Assessment on the Expression Level of Recombinant Human Follicle-Stimulating Hormone (FSH) in Serum-Containing Versus Protein-Free Culture Media

Production of recombinant pharmaceutical proteins has made a great contribution to modern biotechnology. At present, quick advances in protein expression lead to the enhancement of product quantity and quality as well as reduction in timescale processing. In the current study, we assessed the expression level of recombinant human follicle-stimulating hormone (rhFSH) in adherent and suspension Chinese hamster ovary (CHO) cell lines by cultivation in serum-containing and chemically defined, protein-free media. The expression cassette entailing FSH subunits was transfected to CHO/dhfr- and CHO DG44 cell lines, and gene amplification was achieved using dihydrofolate reductase (DHFR)/methotrexate (MTX) system. Afterward, the expression level of rhFSH was studied using real-time PCR, Western blotting and ELISA. Our achievements revealed that stepwise increase in MTX [up to 2000 nano-molar (nM)] leads to boost the expression level of rhFSH mRNA in both cell lines, although DG44 have better results, as mRNA expression level reached 124.8- and 168.3-fold in alpha and beta subunits, respectively. DG44 cells have also the best protein production in 2000 nM MTX, which reached 1.7-fold in comparison with that of the mock group. According to the above results and many advantages of protein-free media, DG44 is preferable cell line for future steps.

Pharmacogenetics of G-protein-coupled receptors variants: FSH receptor and infertility treatment

Infertility treatment may represent a paradigmatic example of precision medicine. Follicle-stimulating hormone (FSH) has been proposed as a valuable therapeutic option both in males and in females, even if a standardized approach is far to be established. To date, several genetic mutations as well as polymorphisms have been demonstrated to significantly affect the pathophysiology of FSH-FSH receptor (FSHR) interaction, although the underlying molecular mechanisms remain unclear. This review aims to highlight possible aspects of FSH therapy that could benefit from a pharmacogenetic approach, providing an up-to-date overview of the variability of the response to FSH treatment in both sexes. Specific sections are dedicated to the clinical use of FSH in infertility and how FSHR polymorphisms may affect the therapeutic endpoints.

Urinary Versus Recombinant Gonadotropins for Ovarian Stimulation in Women Undergoing Treatment with Assisted Reproductive Technology

Globally, about 10%-15% couples are affected by infertility, with major role being played by the couple's lifestyle. Several gonadotropin preparations (urinary, purified urinary, recombinant, and biosimilars) are available for use. Purified urinary formulations offer numerous advantages over their predecessor, including lesser injection dose required, ability to be administered subcutaneously, less batch-to-batch variability, better efficacy, ability to individualize protocols as per patient's need, better control of developing follicles, less risk of multiple pregnancies, and hyperstimulation. Published results of Cochrane reviews and meta-analysis show no difference in efficacy or safety between urinary and recombinant gonadotropins. In the absence of any significant difference, cost plays an important role in deciding choice of gonadotropins. In this article, we have reviewed the results of comparative clinical trials, Cochrane analysis, and meta-analysis to derive consensus statements regarding efficacy, safety, and cost implications of urinary versus recombinant gonadotropin preparations.

Small Molecule Follicle-Stimulating Hormone Receptor Agonists and Antagonists

The follicle-stimulating hormone receptor (FSHR) has been targeted therapeutically for decades, due to its pivotal role in reproduction. To date, only purified and recombinant/biosimilar FSH have been used to target FSHR in assisted reproduction, with the exception of corifollitropin alfa; a modified gonadotropin in which the FSH beta subunit is joined to the C-terminal peptide of the human choriogonadotropin beta subunit, to extend serum half-life. Assisted reproduction protocols usually entail the trauma of multiple injections of FSH to initiate and promote folliculogenesis, which has prompted the development of a number of orally-available low molecular weight (LMW) chemical scaffolds targeting the FSHR. Furthermore, the recently documented roles of the FSHR in diverse extragonadal tissues, including cancer, fat metabolism, and bone density regulation, has highlighted the potential utility of LMW modulators of FSHR activity. Despite these chemical scaffolds encompassing a spectrum of in vitro and in vivo activities and pharmacological profiles, none have yet reached the clinic. In this review we discuss the major chemical classes of LMW molecules targeting the FSHR, and document their activity profiles and current status of development, in addition to discussing potential clinical applications.

In-vivo biological activity and glycosylation analysis of a biosimilar recombinant human follicle-stimulating hormone product (Bemfola) compared with its reference medicinal product (GONAL-f)

Recombinant human follicle-stimulating hormone (r-hFSH) is widely used in fertility treatment. Although biosimilar versions of r-hFSH (follitropin alfa) are currently on the market, given their structural complexity and manufacturing process, it is important to thoroughly evaluate them in comparison with the reference product. This evaluation should focus on how they differ (e.g., active component molecular characteristics, impurities and potency), as this could be associated with clinical outcome. This study compared the site-specific glycosylation profile and batch-to-batch variability of the in-vivo bioactivity of Bemfola, a biosimilar follitropin alfa, with its reference medicinal product GONAL-f. The focus of this analysis was the site-specific glycosylation at asparagine (Asn) 52 of the α-subunit of FSH, owing to the pivotal role of Asn52 glycosylation in FSH receptor (FSHR) activation/signalling. Overall, Bemfola had bulkier glycan structures and greater sialylation than GONAL-f. The nominal specific activity for both Bemfola and GONAL-f is 13,636 IU/mg. Taking into account both the determined potency and the nominal amount the average specific activity of Bemfola was 14,522 IU/mg (105.6% of the nominal value), which was greater than the average specific activity observed for GONAL-f (13,159 IU/mg; 97.3% of the nominal value; p = 0.0048), although this was within the range stated in the product label. A higher batch-to-batch variability was also observed for Bemfola versus GONAL-f (coefficient of variation: 8.3% vs 5.8%). A different glycan profile was observed at Asn52 in Bemfola compared with GONAL-f (a lower proportion of bi-antennary structures [~53% vs ~77%], and a higher proportion of tri-antennary [~41% vs ~23%] and tetra-antennary structures [~5% vs <1%]). These differences in the Asn52 glycan profile might potentially lead to differences in FSHR activation. This, together with the greater bioactivity and higher batch-to-batch variability of Bemfola, could partly explain the reported differences in clinical outcomes. The clinical relevance of the differences observed between GONAL-f and Bemfola should be further investigated.

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.

Biosimilars to recombinant human FSH medicines: comparable efficacy and safety to the original biologic

Two recombinant follicle-stimulating hormone (rFSH)-bearing similar biological medicines (biosimilars) have been authorized by the European Commission. Biosimilar is a regulatory concept alluding to the evidence-based high-standard comparability studies needed to demonstrate its equivalence to a reference original biologic. Because biosimilar development represents a shift from the long-lasting existing paradigms, a thorough understanding of the science behind it will contribute to helping prescribers make informed treatment choices. Contrary to chemically-synthesized medicines, biologics are subject to an inherent molecular variability. From the experience with original biologics, regulatory authorities have accumulated a wealth of knowledge as to what minor batch-to-batch physicochemical variations may be therapeutically acceptable in a given product. Furthermore, in spite of analytically detectable differences, the two original rFSH-bearing medicines currently on the market share fundamentally the same therapeutic profile. Unlike those original medicines, a biosimilar of an rFSH product and the corresponding reference biologic share essentially the same active pharmaceutical ingredient. They are also administered via the same route, at the same dose, and for the same indications. This article revises the background evidence over which the biosimilarity principle has been built, and highlights the therapeutic potential for follitropin biosimilars in order to reassure physicians on their benefit.