Recombinant technique and gonadotropins production: new era in reproductive medicine

Evaluation of Synthetic GnRH-Analog Peforelin with Regard to Oocyte Differentiation and Follicular Development in C57BL/6J Mice

In biomedical research, ovulation induction is a critical step in the reproductive biology of laboratory animals. This study evaluates the efficacy of peforelin, a synthetic gonadotropin-releasing hormone (GnRH) analog, in comparison to pregnant mare serum gonadotropin (PMSG, synonym: eCG), traditionally used for ovulation induction in mice. PMSG is derived from the serum of pregnant horses, and its production is becoming increasingly problematic due to animal welfare concerns and regulatory restrictions. The aim of this study was, therefore, to evaluate an ethically acceptable and less invasive alternative to PMSG. Female C57BL/6J mice, aged 3-4 weeks, were divided into two groups to receive either peforelin at three different concentrations or PMSG, followed by an injection of human chorionic gonadotropin (hCG) to induce ovulation. Key outcomes included the number and quality of oocytes collected, fertilization rates, ovary morphology, and follicular differentiation. Although the number of oocytes was significantly lower in the peforelin cohort, the fertilization rate was high. Ovarian morphology was not significantly altered compared to the PMSG cohort. This study showed that peforelin is suitable for superovulation in mice. These results suggest that peforelin could be an ethically acceptable alternative to PMSG stimulation for inducing superovulation in mice.

Follicle-stimulating hormone (and luteinizing hormone) in ovarian stimulation: Does the dose matter for cycle success?

In this review, we have summarized the evolution in our understanding of a relevance of gonadotropin dosing for cycle outcomes in women attempting to conceive through the utilization of the in vitro fertilization technology.

CRISPR/Cas9: Nature's gift to prokaryotes and an auspicious tool in genome editing

Clustered regularly interspaced short palindromic repeats (CRISPR) is a family of DNA direct repeats found in many prokaryotic genomes. It was discovered in bacteria as their (adaptive) immune system against invading viruses. Cas9 is an endonuclease enzyme linked with the CRISPR system in bacteria. Bacteria use the Cas9 enzyme to chop viral DNA sequences by unwinding it and then finding the complementary base pairs to the guide RNA. CRISPR/Cas9 is a modern and powerful molecular biology approach that is widely used in genome engineering (to activate/repress gene expression). It can be used in vivo to cause targeted genome modifications with better efficiency as compared to meganucleases, zinc-finger nucleases and transcription activator-like effector nucleases. CRISPR/Cas9 is a simple, reliable, and rapid method for causing gene alterations that open new horizons of gene editing in a variety of living organisms, including humans, for the treatment of several diseases. In this short review, we explored the basic mechanisms underlying its working principles along with some of its current applications in a number of diverse fields.

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.

Comparison of the effect of two different doses of recombinant gonadotropin for ovarian stimulation on the outcome of intrauterine insemination

OBJECTIVE

The aim of this study was to identify an optimal stimulation protocol for intrauterine insemination (IUI) to obtain an acceptable pregnancy rate and low frequency of multiple pregnancies.

MATERIALS AND METHODS

In total, 340 patients, who received intrauterine insemination because of ovulation dysfunction, were enrolled in this study. Group I consisted of 203 patients who received recombinant FSH (r-FSH) 150U every other day as an ovulation induction agent. Group II consisted of 137 patients who received r-FSH 100U every other day as an ovulation induction agent. All patients in both groups also received clomiphene citrate 100 mg/day for consecutive five days from the fifth day of the cycle. Only patients with at least two follicles >18 mm on the human chorionic gonadotropin injection days were included in this study.

RESULTS

The clinical pregnancy rate was 14.8% (30/203) in Group I compared with 20.4% (28/137) in Group II, p > 0.05. The incidence of multiple pregnancy was 41.7% (10/24) in Group I compared with 12.5% (3/24) in Group II, p < 0.05.

CONCLUSIONS

The concurrent use of low-dose r-FSH and clomiphene citrate would seem not only to be cost-effective but also highly satisfactory in that it prevents high-order multiple pregnancies.

Comparison of the efficacy and safety of a new recombinant human follicle-stimulating hormone (DA-3801) with follitropin-? (Gonal-F�) in women undergoing controlled ovarian hyperstimulation for assisted reproductive technology

AIM

To compare the efficacy and safety of a new recombinant human follicle-stimulating hormone (FSH; DA-3801) with follitropin-alpha (Gonal-F) in women undergoing controlled ovarian hyperstimulation (COH) for assisted reproductive technology (ART).

METHODS

This was a phase III, multicenter, randomized, non-inferiority study. A total of 97 women were randomized to receive COH using DA-3801 (DA-3801 group, n = 49) or Gonal-F (Gonal-F group, n = 48). All subjects underwent COH using a gonadotropin-releasing hormone (GnRH) antagonist protocol. The primary efficacy endpoint was the number of oocytes retrieved, and the secondary efficacy endpoints included the total dose of FSH, the duration of stimulation, the serum estradiol levels on the day of human chorionic gonadotropin (hCG) administration, and the fertilization, implantation and pregnancy rates. Safety was evaluated using pre- and post-treatment laboratory tests and all adverse events were recorded.

RESULTS

The number of oocytes retrieved was 13.0 +/- 6.2 (DA-3801) versus 10.6 +/- 6.7 (Gonal-F) in the intention-to-treat (ITT) population, and 12.7 +/- 6.4 (DA-3801) versus 11.0 +/- 7.1 (Gonal-F) in the per-protocol (PP) population. The non-inferiority of DA-3801 was demonstrated with differences of 2.3 +/- 6.5 (95% confidence interval [CI] = 0.13, infinity) and 1.7 +/- 6.7 (95% CI = -0.74, infinity), respectively, in the ITT and PP populations. The total dose of FSH used (1789.8 +/- 465.5 vs 2055.6 +/- 646.7 pg/mL, P = 0.027) and duration of stimulation (8.3 +/- 1.4 vs 9.1 +/- 1.9 days, P = 0.036) in the ITT population were significantly lower in the DA-3801 group. Other secondary efficacy endpoints, including pregnancy and implantation rates and the incidence and severity of adverse events, were comparable between the two groups.

CONCLUSIONS

The results of this study demonstrate that DA-3801 is not inferior to follitropin-alpha in terms of its efficacy and safety in women undergoing COH for ART.

Comparison of different gonadotrophin preparations in intrauterine insemination cycles for the treatment of unexplained infertility: a prospective, randomized study

BACKGROUND

A comparison of the effectiveness of different gonadotrophin preparations in intrauterine insemination (IUI) cycles for patients with unexplained infertility was performed.

METHODS

Two hundred and forty-one patients were prospectively randomized using computer-generated random numbers into three groups: 81 in the Follitropin alpha (Group I), 80 in the urinary FSH (uFSH) (Group II) and 80 in the hMG (Group III). The primary outcome was clinical pregnancy rate with duration of stimulation, total gonadotrophin dose, number of dominant follicles, clinical pregnancy rate, multiple pregnancy, miscarriage rate and ovarian hyperstimulation syndrome (OHSS) rate being secondary outcomes.

RESULTS

Clinical pregnancy rate was significantly higher in the rFSH group (25.9% in Follitropin alpha, 13.8% in uFSH and 12.5% in HMG groups; P = 0.04). There was no significant difference in terms of duration of stimulation, but mean FSH dose consumed per cycle was significantly lower in the recombinant FSH (rFSH) group compared with others (825 IU in Follitropin alpha, 1107 IU in uFSH and 1197 IU in HMG groups; P = 0.001). The number of follicles > or =16 mm diameter was significantly higher in the rFSH group compared with the uFSH and HMG groups (2.6 in Follitropin alpha, 1.3 in uFSH and 1.4 in HMG groups; P = 0.001).

CONCLUSION

rFSH may result in a better outcome in IUI cycles for unexplained infertility.

A pen injection device for self-administration of recombinant follicle-stimulating hormone for fertility treatments

A pen injection device modeled on the insulin pen used by diabetic patients has been introduced to deliver recombinant follicle-stimulating hormone to women undergoing controlled ovarian stimulation for in vitro fertilization or other forms of assisted reproductive technology. The pen device makes it easier and less painful for women to self-administer daily injections. The high precision and accuracy of the device enables physicians to fine-tune dosage. The woman simply inserts the multidose cartridge into the Puregon (Follistim) Pen, attaches a BD Micro-Fine Pen Needle, selects the prescribed dose on the dial at the base of the pen, inserts the needle subcutaneously and pushes the injection button to administer the injection. A fresh needle is used for each injection.

Recombinant LH in ovarian stimulation

The advent of recombinant gonadotrophins brought significant changes in fertility therapy. Treatment options with recombinant gonadotrophins add more to knowledge on folliculogenesis and ovarian steroidogenesis. Over a decade, recombinant LH (rLH) has been used for clinical trials, and the amount of peripheral LH that is necessary for optimal follicular growth, oocyte maturation, subsequent embryo development and assisted reproduction outcome during ovulation induction can now be better evaluated. This review evaluates the effect of rLH supplementation on ovarian stimulation and assisted reproduction outcome. The studies conducted with rLH supplementation in ovarian stimulation in different groups of patients and in cases of controlled ovarian stimulation are clearly discussed in this review.

Treatment of female infertility with recombinant human luteinising hormone: is there a benefit over other available drugs?

This manuscript reviews the role of recombinant human luteinising hormone (rhLH) as a therapeutic drug in ovarian stimulation for assisted reproductive technology (ART) and ovulation induction. For this purpose, the role of LH during the follicular phase and during the ovulatory surge, along with the role of human chorionic gonadotropin (hCG) as a surrogate LH, is reviewed and compared to the results available with the new rhLH formulation. The use of rhLH was found to be safe and highly effective given during the follicular phase and to mimic an endogenous LH surge. The availability of both LH and follicle stimulating hormone (FSH) as separate recombinant preparations enables physicians to adjust the doses of each gonadotropin to the individual patient according to the 'therapeutic window' concept for each drug to maximise the success of ovarian stimulation.

Recombinant human follicle-stimulating hormone: a controversial issue--without controversy

Recent developments in recombinant DNA technology have resulted in a rapidly expanding range of new diagnostic and therapeutic opportunities. This technology paved the way for identification, isolation, cloning and production of specific proteins. Recently, recombinant human gonadotropins became available for clinical use. Pharmacokinetics, receptor availability, pharmacodynamics and safety were extensively studied and the drugs were found to be identical, if not superior, to urinary gonadotropins that have been used in reproductive medicine for the last 40 years. It is currently apparent that the use of recombinant human gonadotropins is expected to provide improved batch-to-batch consistency, steady supply and most importantly, a purified compound with highly specific activity, which accounts for > 99% of the protein content of the preparation, making it possible to administer subcutaneously. The purpose of this report is to describe and evaluate recent developments in the use of recombinant human follicle-stimulating hormone.

A prospective randomized clinical trial comparing 150 IU and 225 IU of recombinant follicle-stimulating hormone (Gonal-F*) in a fixed-dose regimen for controlled ovarian stimulation in in vitro fertilization treatment

OBJECTIVE

To compare fixed daily doses of the recombinant FSH (rFSH) Gonal-F (150 IU vs. 225 IU) for ovarian stimulation in IVF-ET.

DESIGN

Single-center prospective, randomized study. Assisted conception unit of a university hospital. One hundred twenty-four women aged 23-41 years participated in the study. Exclusion criteria were as follows: FSH of >10 IU/L, polycystic ovarian syndrome, one ovary or previous ovarian surgery, previous poor response to ovarian stimulation, or ovarian hyperstimulation syndrome (OHSS).

INTERVENTION(S)

Randomized to commence 150 IU or 225 IU of Gonal-F per day without dose alterations during treatment.

MAIN OUTCOME MEASURE(S)

Number of oocytes retrieved and total rFSH dose.

RESULT(S)

More oocytes were retrieved in women aged <or=32 years in the 225-IU compared with the 150-IU group (11.8 +/- 8.0 vs. 7.0 +/- 5.8). In older women (>or=33 years), the number of oocytes retrieved in the two groups were similar. No significant differences were found for fertilization rate, number of embryos formed and cryopreserved, and pregnancy rates between the two groups. The total rFSH dose used was higher in the 225-IU group (2,595.0 +/- 510.0 vs. 1,897.5 +/- 457.5 IU). The cancellation rate due to insufficient ovarian response was higher in the 150-IU group (15.0% vs. 3.3%). All cases of ovarian hyperstimulation syndrome (n = 4) occurred in the 225-IU group.

CONCLUSION(S)

Two hundred twenty-five IU is more effective than 150 IU in younger women but requires a higher total dose of Gonal-F. The use of 225 IU in older women did not result in a higher oocyte yield, suggesting that 225 IU of rFSH does not compensate for the age-related decline in the number of follicles available for stimulation.

Follicular development and hormone concentrations following recombinant FSH administration for anovulation associated with polycystic ovarian syndrome: prospective, randomized comparison between low-dose step-up and modified step-down regimens

The present study compared ovarian performance and hormone concentrations, after ovulation induction, in polycystic ovarian syndrome (PCOS) patients, using recombinant human FSH (rhFSH) in low-dose step-up and modified step-down regimens. Twenty-six women with clomiphene citrate-resistant chronic anovulatory infertility were treated with rhFSH in two consecutive cycles according to two different low-dose regimens: (i) the classic chronic low-dose step-up protocol, the starting dose being 75 IU; (ii) a modified step-down protocol where the starting dose was 300 IU followed by 3 days free of treatment, then rhFSH 75 IU daily was given and stepwise dose increments were performed exactly the same as in the step-up method. Each woman received both treatment approaches, in a randomized order, with an interval of > or = 1 month between treatments. The total number of follicles that were > 10, > 14 and > 17 mm in diameter on the day of human chorionic gonadotrophin (HCG) administration, and thus cycles with HCG cancelled, were significantly increased with the step-up approach. The total number of rhFSH ampoules tended to be higher with the step-down schedule despite the fact that both the mean duration of treatment and the threshold dose were similar with the two low-dose approaches. A physiological step-down approach for ovulation induction in PCOS patients may be more appropriate in order to avoid multifollicular cycles than the step-up approach.

Comparison of two recombinant follicle-stimulating hormone preparations in in-vitro fertilization: a randomized clinical study

A randomized comparison of two recombinant human follicle-stimulating hormone (recFSH) preparations (Gonal-F and Puregon) in ovarian stimulation for in-vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) was carried out at the Infertility Clinic of the Family Federation of Finland. A total of 348 women (aged 22-43 years) suffering from infertility due to miscellaneous causes was recruited. Of these, 344 underwent stimulation using equal starting doses (150 IU/day: Gonal-F n = 164, Puregon n = 158 or 300 IU/day: Gonal-F n = 8, Puregon n = 14) after down-regulation with intranasal buserelin from the mid-luteal phase. Similar clinical pregnancy rates were achieved with both preparations; 33.5% per cycle and 37.4% per embryo transfer (24.5% one-embryo and 75.5% two-embryo transfers, n = 147) with Gonal-F (150 IU/day) and 32.9% per cycle and 36.4% per embryo transfer (30.1% one-embryo and 69.9% two-embryo transfers, n = 145) with Puregon (150 IU/day). The ongoing cumulative pregnancy rates after frozen-thawed embryo transfer were 35.4% with Gonal-F and 37.7% with Puregon. Six cycles were cancelled because of a low response (three in each group). Similar numbers of oocytes were obtained in both groups; 13.0 with 150 IU/day and 6.1 with 300 IU/day Gonal-F, and 12.4 with 150 IU/day and 7.1 with 300 IU/day Puregon. The fertilization and cleavage rates and the incidence of moderate or severe ovarian hyperstimulation syndrome (Gonal-F, 2.0% and Puregon, 0.7%) were also similar. Gonal-F and Puregon were equally and highly effective in stimulation for IVF and ICSI.

Random mutagenesis and screening of complex glycoproteins: expression of human gonadotropins in Dictyostelium discoideum

The soil amoeba Dictyostelium discoideum is a host cell that provides simple genetics in combination with complex protein synthesis. We show that the complex human heterodimeric gonadotropins can be produced and secreted by this organism. Furthermore, both follicle stimulation hormone and choriogonadotropin produced by D. dictyostelium bind to their human receptors and elicit a biological response comparable to the wild-type hormones. We also show that structure-function analysis using random mutagenesis and screening of recombinant glycoprotein hormones is feasible. Thus, expression of gonadotropins in D. dictyostelium opens the way to the engineering of potential new therapeutic analogues.

Infertility in women: an update

OBJECTIVE

To review pharmacologic therapy of infertility disorders in women.

DATA SOURCES

Current clinical literature.

STUDY SELECTION

Not applicable.

DATA EXTRACTION

Not applicable.

DATA SYNTHESIS

The complex interplay of hormones and cells is the focus of most pharmacotherapeutic interventions in women with infertility problems. Treatment remains more of an art than a science at this time. Since the cause of infertility cannot be identified in many cases, practitioners use medications to overcome potential problems with anovulation, secondary ovarian failures, hypothalamic-pituitary dysfunction, and hyperprolactinemia. This article reviews the use of clomiphene, human chorionic gonadotropin, menotropins such as human menopausal gonadotropin and urofollitropin, gonadotropin-releasing hormone, and dopamine agonists.

CONCLUSION

Although few pharmacists are closely involved in the treatment of women with infertility, they can be sources of information, monitor families for signs and symptoms of psychologic stress associated with treatments, and help patients with practical instructions.