A biological, immunological and physico-chemical comparison of the current clinical batches of the recombinant FSH preparations Gonal-F and Puregon

Overlapping biosimilar and originator follitropin alfa preparations: How much closer can they get?

Unfounded skepticism relating to biosimilars, arising from the assertion that they are not molecularly identical to their original counterpart, fails to acknowledge that no biological medicine, including Gonal-f® (from Merck Serono) is identical to itself. Molecular differences between the biosimilar and the reference medicines are irrelevant and clinically undetectable as long as they are contained within the accepted variability in the original medicine. Accordingly, the minor differences in 'ongoing pregnancy rate' and 'live birth' rate reported in a recent meta-analysis of biosimilars and Gonal-f® are probably driven by product-unrelated factors, notwithstanding the fact that of the four products under analysis, only Ovaleap® (from Theramex) and Bemfola® (from Gedeon Richter Plc) can unambiguously be considered to be biosimilars. The EU biosimilars model has proven successful, but given the distrust in biosimilars that is built on a biased foundation, the full promise of rFSH alfa biosimilars for reproductive medicine patients is unlikely to be fulfilled.

Follitropin alpha versus beta in a first GnRH antagonist ICSI cycle: a retrospective cohort study

RESEARCH QUESTION

Are cumulative live birth rates (CLBR) after follitropin alpha (Ovaleap®) and follitropin beta (Puregon®) similar when used for ovarian stimulation with ICSI (intracytoplasmic sperm injection) in a first-rank gonadotrophin-releasing hormone (GnRH) antagonist protocol?

DESIGN

Retrospective single-centre cohort study including 832 infertile patients undergoing ovarian stimulation with a daily dose of 150-225 IU FSH in their first ICSI cycle at a tertiary referral centre between July 2016 and July 2019. Of those, 349 patients used Ovaleap and 483 patients received Puregon.

RESULTS

Baseline characteristics were not statistically different between the groups. The duration of stimulation was slightly longer in the Ovaleap group (10.6 ± 1.7 versus 10.3 ± 1.6 days; P = 0.012). The number of mature oocytes was not statistically different and there was no significant difference in fertilization rate or embryo utilization rate between the two groups. After fresh embryo transfer, biochemical pregnancy rate (137/349 [39.3%] versus 186/483 [38.5%]) as well as clinical pregnancy rate (105/349 [30.1%] versus 152/483 [31.5%]) were comparable (P = 0.83 and 0.67, respectively). Live birth rate (LBR) after fresh embryo transfer (94/349 [26.9%] versus 141/483 [29.2%]; P = 0.48) and CLBR (199/349 [57.0%] versus 287/483 [59.4%]; P = 0.49) were not significantly different. Multivariable regression analysis revealed that the type of gonadotrophin was not associated with CLBR (P = 0.28).

CONCLUSION

This retrospective study shows no significant difference in CLBR between Ovaleap and Puregon in patients undergoing their first GnRH antagonist ICSI cycle.

The rate of high ovarian response in women identified at risk by a high serum AMH level is influenced by the type of gonadotropin

The aim was to compare ovarian response and clinical outcome of potential high-responders after stimulation with highly purified menotropin (HP-hMG) or recombinant follicle-stimulating hormone (rFSH) for in vitro fertilisation/intracytoplasmic sperm injection. Retrospective analysis was performed on data collected in two randomized controlled trials, one conducted following a long GnRH agonist protocol and the other with an antagonist protocol. Potential high-responders (n = 155 and n = 188 in the agonist and antagonist protocol, respectively) were defined as having an initial anti-Müllerian hormone (AMH) value >75th percentile (5.2 ng/ml). In both protocols, HP-hMG stimulation in women in the high AMH category was associated with a significantly lower occurrence of high response (≥15 oocytes retrieved) than rFSH stimulation; 33% versus 51% (p = 0.025) and 31% versus 49% (p = 0.015) in the long agonist and antagonist protocol, respectively. In the potential high-responder women, trends for improved live birth rate were observed with HP-hMG compared with rFSH (long agonist protocol: 33% versus 20%, p = 0.074; antagonist protocol: 34% versus 23%, p = 0.075; overall population: 34% versus 22%, p = 0.012). In conclusion, the type of gonadotropin used for ovarian stimulation influences high-response rates and potentially clinical outcome in women identified as potential high-responders.

Gonadotropin therapy in assisted reproduction: an evolutionary perspective from biologics to biotech

Gonadotropin therapy plays an integral role in ovarian stimulation for infertility treatments. Efforts have been made over the last century to improve gonadotropin preparations. Undoubtedly, current gonadotropins have better quality and safety profiles as well as clinical efficacy than earlier ones. A major achievement has been introducing recombinant technology in the manufacturing processes for follicle-stimulating hormone, luteinizing hormone, and human chorionic gonadotropin. Recombinant gonadotropins are purer than urine-derived gonadotropins, and incorporating vial filling by mass virtually eliminated batch-to-batch variations and enabled accurate dosing. Recombinant and fill-by-mass technologies have been the driving forces for launching of prefilled pen devices for more patient-friendly ovarian stimulation. The most recent developments include the fixed combination of follitropin alfa + lutropin alfa, long-acting FSH gonadotropin, and a new family of prefilled pen injector devices for administration of recombinant gonadotropins. The next step would be the production of orally bioactive molecules with selective follicle-stimulating hormone and luteinizing hormone activity.

Effect of sialylation and complexity of FSH oligosaccharides on inhibin production by granulosa cells

Granulosa cell (GC) inhibin A and B production is regulated by FSH and gonadal factors. This gonadotrophin is released as a mixture of glycoforms, which induce different biological responses in vivo and in vitro. Our aim was to determine the effect of recombinant human FSH (rhFSH) glycosylation variants on inhibin A and B production by rat GCs. Preparative isoelectro focusing was used to isolate more acidic/sialylated (pH <4.00) and less acidic/sialylated (pH >5.00) rhFSH charge analogues. Concanavalin A was used to isolate unbound and firmly bound rhFSH glycoforms on the basis of their oligosaccharide complexity. GCs, obtained from oestrogen-primed immature rats, were cultured with either native rhFSH or its glycosylation variants. Inhibin A and B were determined using specific ELISAs. Results were expressed as mean±s.e.m. Under basal conditions, inhibin A was the predominant dimer produced (inhibin A: 673±55; inhibin B: 80±4 pg/ml). More acidic/sialylated charge analogues stimulated inhibin B production when compared to inhibin A at all doses studied; by contrast, less acidic/sialylated charge analogues stimulated inhibin A production and elicited no effect on inhibin B. Glycoforms bearing complex oligosaccharides showed a potent stimulatory effect on inhibin B when compared to inhibin A production (i.e. dose 1 ng/ml: 4.9±0.5 vs 0.9±0.1-fold stimulation, P<0.001). Glycoforms bearing hybrid-type oligosaccharides favoured inhibin A production (i.e. dose 4 ng/ml 2.9±0.1 vs 1.6±0.1-fold stimulation, P<0.05). These results show that the sialylation degree as well as the complexity of oligosaccharides present in the rhFSH molecule may be considered additional factors that differentially regulate dimeric inhibin production by rat GCs.

Efficacy of recombinant human follicle stimulating hormone at low doses in inducing spermatogenesis and fertility in hypogonadotropic hypogonadism

BACKGROUND

Recombinant-FSH (rFSH) added to hCG at dose of 450 IU weekly is effective in inducing spermatogenesis in patients with hypogonadotropic hypogonadism (HH), but there are no data on the use of lower doses.

AIM

This observational retrospective study evaluated whether 150-225 IU of rFSH weekly were able to induce spermatogenesis in HH men who failed to start it with hCG alone.

SUBJECTS AND METHODS

Thirty-four patients with pre-pubertal onset HH (20-44 yr old) without adverse fertility factors were considered for this study. After hCG pre-treatment they received also either rFSH (Group 1) or highly purified urinary FSH (hpFSH) (Group 2) 75 IU sc 2 or 3 times weekly. Semen analysis was performed every 3 months during pre-treatment and the 1st yr of combined therapy. Patients were also invited to refer pregnancies in their partners during the subsequent 12 months.

RESULTS

Total sperm count/ejaculate did not show significant difference between 2 groups, while a significantly higher forward motility was observed in Group 1 (p<0.05). The median times to achieve sperm output thresholds (first sperm appearance, sperm concentration >1.5 or >5 mil/ml) were significantly lower in Group 1 (p<0.04, 0.03, and 0.001, respectively). A tendency to a shorter time to pregnancy was shown in partners of Group 1.

CONCLUSIONS

Our data indicate that lower rFSH week dose than that so far used was able to induce potentially fertilizing sperm output in HH men previously treated with hCG. The rFSH effects are comparable to those of hpFSH but with a trend to a faster outcome achievement.

Comparison of urinary and recombinant follicle-stimulating hormone in in vitro growth, maturation, and fertilization of mouse preantral follicles

OBJECTIVE

To compare the effects of urinary and recombinant follicle-stimulating hormone (FSH) on follicular development, oocyte maturation, and fertilization.

DESIGN

Prospective randomized animal study.

SETTING

University-based research laboratory.

ANIMAL(S)

Normal (C57BL/6xDBA2) F1 mice.

INTERVENTION(S)

Collection of preantral follicles by mechanical dissection, in vitro growth (IVG) with urinary or recombinant FSH (100 mIU/mL), in vitro maturation (IVM), and fertilization.

MAIN OUTCOME MEASURE(S)

During IVG, follicle diameter and antral formation were evaluated. The number of cells per follicle was evaluated at the end of IVG. The 17beta-estradiol measurements were performed from conditioned media. After IVM, mucification and oocyte maturation rates were estimated and mature oocytes were fertilized.

RESULT(S)

No differences were observed in the antral formation rate of either group. Antral follicles in the urinary FSH group, however, showed a higher diameter but a lower number of cells per follicle than those in the recombinant FSH group. The level of 17beta-estradiol was also higher in the recombinant FSH group. The rate of mature oocytes developing into metaphase I or II was statistically significantly higher in the recombinant FSH group than in the urinary FSH group.

CONCLUSION(S)

Recombinant FSH provided better conditions than urinary FSH for the growth and development of mouse preantral follicles that could produce mature oocytes with fertilization capacity.

Spectrotemporal changes in electrical activity of myometrium due to recombinant follicle-stimulating hormone preparations follitropin alfa and beta

OBJECTIVE

To investigate the effects of follitropin alfa and beta on the myoelectrical activity of rat myometrium using signal-processing techniques.

DESIGN

Prospective, placebo-controlled study.

SETTING

Animal and pharmacology laboratory at Inonu University.

ANIMAL(S)

Forty-five female Wistar albino rats.

INTERVENTION(S)

Thirty of 45 animals involved in the experiment were registered as the superovulation group. After two successive normal estrous cycles, these animals were put into three equal subgroups. Group 1 was the control; animals were given 0.9% saline. Groups 2 and 3 were treated with follitropin alfa (Gonal-f) and follitropin beta (Puregon), respectively. The other 15 animals were ovariectomized (OVX) and subjected to the same protocol. The uterine myoelectrical signals were recorded and analyzed using a Matlab environment.

MAIN OUTCOME MEASURE(S)

Power/second, variance, and the effects of recombinant human follicle-stimulating hormone (FSH) on myoelectrical signals were assessed through temporal, spectral, and joint time-frequency analysis. The uterine endometrium and ovarian morphology were also assessed concerning primary follicles, antral follicles, and corpora lutea.

RESULT(S)

The power and some characteristic spectral components of myoelectrical signal were reduced with the administration of follitropin alfa and beta. No statistically significant difference was detected between endometrial and ovarian histology of the rats treated with these follitropins.

CONCLUSION(S)

Uterine myoelectrical signals change with administration of recombinant human FSH preparations. Follitropin beta and, more precisely, follitropin alfa suppress the spectral components and power of the myoelectrical signals, which provides uterine quiescence.

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.

Analysis of intact human follicle-stimulating hormone preparations by reversed-phase high-performance liquid chromatography

A reversed-phase high-performance liquid chromatography (RP-HPLC) method for the qualitative and quantitative analysis of intact human follicle-stimulating hormone (hFSH) was established and validated for accuracy, precision and sensitivity. Human FSH is a dimeric glycoprotein hormone widely used as a diagnostic analyte and as a therapeutic product in reproductive medicine. The technique developed preserves the protein integrity, allowing the analysis of the intact heterodimeric form rather than just of its subunits, as is the case for the majority of the conditions currently employed. This methodology has also been employed for comparing the relative hydrophobicity of pituitary, urinary and two Chinese hamster ovary (CHO)-derived hFSH preparations, as well as of two other related glycoprotein hormones of the anterior pituitary: human thyroid-stimulating hormone (hTSH) and human luteinizing hormone (hLH). The least hydrophobic of the three glycohormones analyzed was hFSH, followed by hTSH and hLH. A significant difference (p<0.005) was observed in t(R) between the pituitary and recombinant hFSH preparations, reflecting structural differences in their carbohydrate moieties. Two main isoforms were detected in urinary hFSH, including a form which was significantly different (p<0.005) from the pituitary and recombinant preparations. The linearity of the dose-response curve (r=0.9965, n=15) for this RP-HPLC methodology, as well as an inter-assay precision of less than 4% for the quantification of different hFSH preparations and a sensitivity of the order of 40 ng, were demonstrated. The chromatographic behaviour and relative hydrophobicity of the individual subunits of the pituitary and recombinant preparations were also analyzed. Furthermore, the molecular mass of individual hFSH subunits and of the heterodimer were simultaneously determined by matrix-assisted laser desorption ionization time-of-flight mass spectral analysis (MALDI-TOF-MS). The present methodology represents, in our opinion, an essential tool for the characterization and quality control of this hormone, that is not yet described in the main pharmacopoeias.

Fractionation of follicle stimulating hormone charge isoforms in their native form by preparative electrophoresis technology

Complex glycoprotein biopharmaceuticals, such as follicle stimulating hormone (FSH), erythropoietin and tissue plasminogen activator consist of a range of charge isoforms due to the extent of sialic acid capping of the glycoprotein glycans. Sialic acid occupies the terminal position on the oligosaccharide chain, masking the penultimate sugar residue, galactose from recognition and uptake by the hepatocyte asialoglycoprotein receptor. It is therefore well established that the more acidic charge isoforms of glycoprotein biopharmaceuticals have higher in vivo potencies than those of less acidic isoforms due to their longer serum half-life. Current strategies for manipulating glycoprotein charge isoform profile involve cell engineering or altering bioprocesss parameters to optimise expression of more acidic or basic isoforms, rather than downstream separation of isoforms. A method for the purification of a discrete range of bioactive recombinant human FSH (rhFSH) charge isoforms based on Gradiflowtrade mark preparative electrophoresis technology is described. Gradiflowtrade mark electrophoresis is scaleable, and incorporation into glycoprotein biopharmaceutical production bioprocesses as a potential final step facilitates the production of biopharmaceutical preparations of improved in vivo potency.

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.

Comparative assessment of the consistency and quality of a highly purified FSH extracted from human urine (urofollitropin) and a recombinant human FSH (follitropin α)

The revolutionary development of biotechnology-derived therapeutic proteins has provided the expected improvements in quality, purity and consistency, as demonstrated in recombinant human FSH (rhFSH). However, the development of urine-derived gonadotrophins has not always shown comparable improvements. More recently, highly purified urine-derived FSH (uFSH-HP) products have become widely available. The relative purity, level of urine-derived contaminants, and consistency of one such highly purified human uFSH (uhFSH) (urofollitropin) has been assessed and directly compared with rhFSH (follitropin alpha). It has been demonstrated that the highly purified urofollitropin contains variable levels of urine-derived contaminant proteins and demonstrates a variable level of FSH purity, FSH isoforms, and delivered dose. These variable factors may contribute to the control of ovarian stimulation. The relative purity, variable consistency and the presence of contaminants indicates that the urofollitropin is, at best, a partially purified uFSH that is not able to meet the quality attributes of follitropin alpha (rhFSH).

Mixed protocols: multiple ratios of FSH and LH bioactivity using highly purified, human-derived FSH (BRAVELLE) and highly purified hMG (MENOPUR) are unaltered by mixing together in the same syringe

BACKGROUND

The use of mixed or blended protocols, that utilize both FSH and hMG, for controlled ovarian hyperstimulation is increasing in use. To reduce the number of injections a patient must administer, many physicians instruct their patients to mix their FSH and hMG together to be given as a single injection. Therefore, the goal of this study was to definitively determine if the FSH and LH bioactivities of highly purified, human-derived FSH (Bravelle) and highly purified hMG (Menopur) were altered by reconstituting in 0.9% saline and mixing in the same syringe.

METHODS

Bravelle and Menopur were reconstituted in 0.9% saline and mixed in a Becton Dickinson plastic syringe. The FSH and LH bioactivities of the products were determined after injecting female and male rats, respectively, with Bravelle, Menopur, or a mixture of Bravelle and Menopur. Ratios of FSH:LH activity tested were 150:75 IU (1 vial Bravelle: 1 vial Menopur), 300:75 IU (3 vials Bravelle: 1 vial Menopur) or 300:225 IU (1 vial Bravelle: 3 vials of Menopur).

RESULTS

There were no statistically significant changes in either FSH or LH bioactivity that occurred after mixing Bravelle with Menopur in the same syringe. The theoretical vs. actual FSH bioactivity for Bravelle and Menopur were 75 vs. 76.58 IU/mL and 75 vs. 76.0 IU/mL, respectively. For the 3 ratios of FSH:LH activity tested, 150:75 IU (1 vial Bravelle: 1 vial Menopur), 300:75 IU (3 vials Bravelle: 1 vial Menopur) or 300:225 IU (1 vial Bravelle: 3 vials of Menopur) tested, the theoretical vs. actual FSH bioactivities were 150 vs. 156.86 IU/mL, 300 vs. 308.69 IU/mL and 300 vs. 306.58 IU/mL, respectively. The theoretical vs. actual LH bioactivity for Menopur in the above mentioned ratios tested were 75 vs. 77.50 IU/mL. For the 3 ratios of FSH:LH activity tested, 150:75 IU (1 vial Bravelle: 1 vial Menopur), 300:75 IU (3 vials Bravelle: 1 vial Menopur) or 300:225 IU (1 vial Bravelle: 3 vials of Menopur), the theoretical vs. actual LH bioactivities were 75 vs. 78.38 IU/mL, 75 vs. 78.63 IU/mL and 225 vs. 233.48 IU/mL, respectively.

CONCLUSION

Mixing human-derived FSH (Bravelle) with highly purified hMG (Menopur) in the same diluent, 0.9% NaCL, does not alter the FSH or LH bioactivity of either gonadotropin preparation.

Batch-to-batch consistency of human-derived gonadotrophin preparations compared with recombinant preparations

Different gonadotrophin preparations derived from human urine or manufactured by recombinant technology are currently used in clinical practice for the treatment of infertility. It has been widely assumed that gonadotrophin products manufactured by recombinant technology have better batch-to-batch consistency compared with human-derived preparations and that this potentially will be shown to provide a more constant clinical response, but there is little evidence for either statement. This study compared the batch-to-batch consistency between urinary-derived and recombinant manufactured gonadotrophin preparations using standard analytical techniques, as well as a novel in-vitro follicle bioassay to evaluate the consistency of the biological response at the target organ. Oligosaccharide isoform profiling, immunoassay testing, size exclusion chromatography analysis and in-vitro bioassay testing of urinary derived gonadotrophin preparations (MENOPUR and BRAVELLE) confirm that these products display a high degree of batch-to-batch consistency, similar to recombinant FSH (GONAL-f) either filled by mass or bioassay. The data also suggest that the batch-to-batch variation is independent of the manufacturing procedure (filled-by-bioassay or filled-by-mass) for the recombinant preparation (Gonal-f), but that the total FSH bioactivity delivered from a single dose preparation after reconstitution differs between the two manufacturing procedures.

Continued improvements in the quality and consistency of follitropin alfa, recombinant human FSH

The use of gonadotrophins for the treatment of infertility began in the 1930s following early work on the pituitary-ovarian axis and the discovery of FSH and LH. The technological development of pharmaceutical gonadotrophins over the last 40 years has shown improvements in specific activity, purity, degradation and impurities. Throughout these pharmaceutical developments the gonadotrophin content of both urinary and recombinant preparations has been assessed using an animal in-vivo bioassay. This paper reflects upon the manufacturing history of recombinant human FSH (r-hFSH) and follitropin alfa filled by mass (FbM), and evaluates the impact of introducing a pharmaceutical product that is formulated and assayed by a physicochemical method for r-hFSH protein content. It also compares the analytical consistency of follitropin alfa FbM with another commercially available r-hFSH, follitropin beta.

Factors influencing response to ovarian stimulation

Ovarian stimulation is an integral part of assisted reproduction treatments. Ovarian response to gonadotrophin treatment, besides other factors, determines the outcome of treatment, as the number and quality of oocytes retrieved are related to the chance of achieving a pregnancy. A number of factors have been identified that might predict ovarian response, such as age of the patient and antral follicle count. In addition, it has been shown that genetic factors such as the patient's FSH-receptor genotype also determine individual response to FSH treatment. Besides patient-related factors, the choice of drugs for ovarian stimulation plays a significant role. Until recently, biopotency of gonadotrophin preparations was tested by an in-vivo bioassay with an intrinsic variability up to 20%. Due to a superior manufacturing technique, follitropin alpha can now be filled by mass. This allows assessment of FSH with a precise SE-HPLC assay and variability of the FSH content between production lots has now been estimated at 1.6%. Results of recent studies indicate that treatment with follitropin alpha filled by mass results in consistent ovarian response, fewer treatment days and fewer cancelled cycles. This is an important step towards further minimizing drug-related variability of ovarian response to FSH treatment.

Pregnancy rates in varying age groups after in vitro fertilization: a comparison of follitropin alfa (Gonal F) and follitropin beta (Follistim)

OBJECTIVE

Our purpose was to assess the efficacy of two recombinant follicle-stimulating hormones, follitropin beta (Follistim, Organon, West Orange, NJ) and follitropin alfa (Gonal F, Serono, Norwell, Mass) on pregnancy rates in varying age groups of women undergoing in vitro fertilization (IVF).

STUDY DESIGN

Three hundred sixty-five IVF cycles were retrospectively compared, 233 by use of follitropin beta and 132 by use of follitropin alfa, both after gonadotropin-releasing hormone agonist down-regulation. Assignment to each medication was indiscriminate. The primary outcome measured was pregnancy evidenced by fetal heartbeat on ultrasonography. Secondary outcomes included days of stimulation, ampules per patient cycle, estradiol level on the day of human chorionic gonadotropin administration, total follicles present on the day of human chorionic gonadotropin administration, follicles greater than 14 mm, oocytes retrieved, mature eggs, fertilization rate, and embryos transferred. Outcomes were stratified by age, including women less than 36 years old, 36 to 39 years old, and more than 39 years old.

RESULTS

There was no significant difference between follitropin beta and follitropin alfa in either the primary or secondary outcomes, although the pregnancy rate was significantly decreased with advancing age.

CONCLUSION

Success rates are similar, when stratified by age, in women undergoing IVF with either follitropin beta or follitropin alfa.

New developments in gonadotrophin pharmacology

This article reviews the past, present, and future of gonadotrophin therapy, including purification of gonadotrophins from animal or human urine sources and production of gonadotrophins through recombinant technology. With the advent of recombinant DNA methodologies combined with site-directed mutagenesis, a variety of structural modifications becomes possible.

Clinical experience with recombinant follicle-stimulating hormone (FSH) and urinary FSH: a retrospective case- controlled analysis

OBJECTIVE

To compare the efficacy and efficiency of recombinant FSH (rFSH) and urinary FSH (uFSH).

DESIGN

Retrospective case controlled analysis.

SETTING

An assisted reproduction unit at a university center.

PATIENT(S)

1388 patients undergoing long protocol in vitro fertilization/embryo transfer (IVF-ET) using buserelin acetate from day 2 of the cycle and either rFSH (follitropin beta) (n = 694) or uFSH (n = 694) with equal number of ampules started (rFSH: 50 IU, uFSH: 75 IU).

INTERVENTION(S)

Patients were included in the two groups of treatment after matching for similarity in age and type of treatment (IVF or intracytoplasmic sperm injection).

MAIN OUTCOME MEASURE(S)

Total dose of FSH, ovarian response, and IVF outcome.

RESULT(S)

Patients who received uFSH experienced a shorter period of stimulation, and a higher number of oocytes were collected. The total FSH used was lower in the rFSH group, and they required a lower FSH dose per oocyte retrieved. The implantation and pregnancy rates were similar between the uFSH and rFSH groups. In both groups implantation and pregnancy rates were higher when intracytoplasmic sperm injection was performed as compared with IVF.

CONCLUSION(S)

The implantation and pregnancy rates are similar when either rFSH or uFSH is used (when compared on an ampule-to-ampule basis, rFSH: 50 IU, and uFSH: 75 IU). However, a significantly lower total FSH dose was used in the rFSH group with a lower FSH dose per oocyte collected.