Randomized Pharmacokinetic Study of a Highly Purified Human Chorionic Gonadotropin and of a Recombinant Human Chorionic Gonadotropin Following Single Subcutaneous Administration in Healthy Women.

BACKGROUND AND OBJECTIVES: Exogenous human chorionic gonadotropin (hCG) acts on the final phase of the follicle maturation. Choriomon®, a highly purified hCG formulation, is approved in many European and extra-European countries for the induction of ovulation after stimulation of follicular development. The present study compares hCG bioavailability of Choriomon® (Test product) versus a recombinant hCG preparation (Ovitrelle®; Reference product). METHODS: In this randomized, two-way cross-over study, 26 healthy women received a single dose of Choriomon® (10,000 IU) and Ovitrelle® (250 µg; 6500 IU) by subcutaneous injection. hCG was determined in serum up to 192 h post-dose. Dose-normalized peak concentration (Cmax) and area under the concentration-time curve up to the time of the last quantifiable concentration (AUC0-t) and extrapolated to infinity (AUC0-∞) were calculated and compared between the two treatments. RESULTS: Serum hCG concentrations increased rapidly with a very similar pharmacokinetic curve for the two products. The test/reference geometric means ratio (GMR) for AUC0-t and AUC0-∞ corresponded to 121.31 and 119.81%, and the upper limits of the 90% confidence intervals (CIs) (130.21% and 128.51%, for AUC0-t and AUC0-∞, respectively) exceeded the 125% bioequivalence threshold. Cmax GMR was 146.89%, indicating a rate of hCG absorption approximately 50% greater for the test product (90% CI 132.30-163.10). Half-life (t1/2) was very similar (36.77 ± 5.11 h and 38.63 ± 6.08 h), whereas time to achieve Cmax (tmax) significantly differed, with median values of 16 h and 24 h for Choriomon® and Ovitrelle®, respectively, (p = 0.0023). CONCLUSIONS: The differences between Choriomon® and Ovitrelle® pharmacokinetic parameters can be ascribed to the different raw source of the products and are reflected in the approved dose regimens of the two hCG formulations. The observed lack of bioequivalence between the two compounds at the given doses is not clinically relevant, as results from Phase III studies indicated similar clinical efficacy and safety. The safety data are in line with the known safety profile of the two products. GOV REGISTRATION NO: NCT03735030.

First-in-human trial assessing the pharmacokinetic-pharmacodynamic profile of a novel recombinant human chorionic gonadotropin in healthy women and men of reproductive age.

The purpose of this first-in-human trial was to examine the safety, pharmacokinetics (PK), and pharmacodynamics (PD) of a novel recombinant human chorionic gonadotropin (rhCG; FE 999302, choriogonadotropin beta) to support its clinical development for various therapeutic indications. The single and multiple dose PK of choriogonadotropin beta (CG beta) were evaluated in women and the single dose PK and PD of CG beta were compared to those of CG alfa in men. CG beta was safe and well-tolerated in all 84 healthy subjects. In women, the area under the curve (AUC) and the peak serum concentration (Cmax ) increased approximately dose proportionally following single and multiple doses of CG beta. The apparent clearance (CL/F) was ~ 0.5 L/h, the mean terminal half-life (t½ ) ~ 45 h and the apparent distribution volume (Vz /F) ~ 30 L. After single administration in men, the mean AUC was 1.5-fold greater for CG beta than for CG alfa. Mean Cmax and Vz /F were comparable for the 2 preparations. In accordance with the differences in AUC, the CL/F was lower for CG beta (CL/F 0.5 vs. 0.8 L/h), explained by a longer t½ (47 vs. 32 h). Serum testosterone levels induced by a single dose rhCG reflected the PK profiles with a slight delay, resulting in 59% higher AUC for CG beta. The PK parameters for CG beta were comparable in men and in women. In conclusion, the PK differs between the two rhCG preparations, causing higher exposure and a higher PD response for CG beta, which may require relatively lower therapeutic doses.

Comparative Pharmacokinetics, Bioequivalence and Safety Study of Two Recombinant Human Chorionic Gonadotropin Injections in Healthy Chinese Subjects.

OBJECTIVE: To evaluate the pharmacokinetics (PK), bioequivalence and safety profile of the recombinant human chorionic gonadotropin (r-hCG) injection formulation LZM003 (test drug) comparing with that of Ovidrel® (reference drug) in healthy Chinese subjects. METHODS: This is a randomized, single-blind, single-dose, two-arm and two-period crossover Phase I study. Subjects were randomized evenly to a single dose of LZM003 or reference drug injected subcutaneously, with a 10-day or longer between-treatment washout period. PK parameters, anti-drug antibodies (ADAs), and adverse events (AEs) were assessed. The primary PK endpoints were area under the curve (AUC) of the concentration-time curve from zero to last quantifiable concentration (AUC0-t), AUC from zero to infinity (AUC0-∞), and peak concentration (Cmax). Bioequivalence was determined by assessing whether the 90% confidence intervals (CIs) for the geometric mean ratio (GMR) of LZM003 to reference drug fell within predefined margins of 80% -125%. RESULTS: Forty-eight subjects (24 males and 24 females) were enrolled and one subject withdrew for personal reasons. Mean values of primary PK parameters were similar (p > 0.05) between LZM003 and the reference drug. The 90% CIs for primary PK endpoints' GMR of LZM003 to reference drug ranged between 0.9144 and 1.1845, which were within bioequivalence margins of 80-125%. Incidence of AEs was similar (p > 0.05) between the two groups. Neither LZM003 nor reference drug produced anti-drug antibody (ADA) in healthy subjects. CONCLUSION: LZM003 and reference drug were bioequivalent. The PK and safety assessments were similar (p > 0.05) between the two formulations in healthy Chinese subjects. TRIAL REGISTRATION NUMBER: ChiCTR-IIR-16010158 (http://www.chictr.org.cn). TRIAL REGISTRATION DATE: December 15, 2016.

Choice of protocol for the in vivo bioassay of equine Chorionic Gonadotropin (eCG / PMSG) in immature female rats.

Equine Chorionic Gonadotropin (eCG) previously known as Pregnant Mare Serum Gonadotropin (PMSG) has been used for decades in regulating reproduction in various domestic animal species. Its use necessitates a good measurement of its bioactivity in commercial preparations. The EUROPEAN PHARMACOPEIA (EP 7.0) recommends 5-6 subcutaneous injections in immature female rats for the in vivo bioassay for eCG as in the case for measurement of FSH bioactivity in the Steelman & Pohley assay (1953). This recommendation is in marked contrast with the classical and long-time used PMSG assay of Cole & Erway (1941) that includes only one subcutaneous injection, 3 days before measurement of ovarian weight. As this difference introduces much confusion in the determination of eCG/PMSG bioactivity in commercial sources, we have performed parallel assays of several PMSG preparations, with both protocols. The single-injection protocol takes into account the long half-life of eCG in bloodstream and provokes an ovarian stimulation at lower concentrations than the multiple-injection protocol. As the single-injection protocol also mimicks the protocol used in cattle, it is preferable to the multiple-injection protocol of the current EP.

Effect of protease inhibitors on pulmonary bioavailability of therapeutic proteins and peptides in the rat.

The objective of the present study was to evaluate the effect of protease inhibitors on the pulmonary absorption of therapeutic peptides and proteins with varying molecular weights. Dry powder formulations of leuprolide (1.2 kD), salmon calcitonin (3.4 kD), human insulin (5.8 kD), human leptin (16.0 kD), and human chorionic gonadotropin (HCG) (36.5 kD) were prepared with or without protease inhibitors; aprotinin and bestatin. The formulations were administered intrapulmonary to anesthetized rats. The pharmacokinetics of these proteins were assessed by measuring serum drug concentrations. In addition, in vitro stability of these proteins in rat lung homogenate was assessed using the trifluoroacetic acid method. Bioavailability of leuprolide following pulmonary administration was 75% higher compared to subcutaneously administered leuprolide. Protease inhibitors had little or no effect on the pulmonary bioavailability of leuprolide. However, protease inhibitors (1 mg/kg) increased the bioavailability of calcitonin by more than 50%. Similarly, the bioavailabilities of leptin and HCG in the presence of bestatin were increased by 1.9 and 2.1-fold, respectively. Leuprolide was stable both in the lung cytosol and subcellular pellets with about 10% degradation at the end of the study period (4h). In contrast, calcitonin, insulin, leptin and HCG were significantly degraded in the lung cytosol and subcellular pellets. Presence of protease inhibitors in formulation could improve the stability of protein drugs. The results of this study demonstrate that the pulmonary absorption of proteins may be enhanced by the selection of optimal concentration and type of protease inhibitor.

Pharmacokinetics of human chorionic gonadotropin injection in obese and normal-weight women.

CONTEXT: Obese women have poorer in vitro fertilization outcomes, but underlying mechanisms remain unclear. OBJECTIVE: The objectives of the study were to compare the pharmacokinetics of human chorionic gonadotropin (hCG) and ovarian steroid hormone production, after subcutaneous (s.c.) and intramuscular (i.m.) injection of hCG in obese and normal-weight women. DESIGN AND SETTING: This was a randomized, experimental study. PATIENTS OR OTHER PARTICIPANTS: Twenty-two women aged 18-42 years with body mass index of 18.5-24.9 (normal) or 30-40 kg/m(2) (obese). INTERVENTIONS: Participants received im urinary hCG or s.c. recombinant hCG and returned for a second injection type after a 4-week washout. Intramuscular injections were performed under ultrasound guidance. Blood was taken 0, 0.5, 1, 2, 4, 6, 8, 12, 24, and 36 hours after injection. MAIN OUTCOME MEASURES: hCG was measured at each time point; estradiol, progesterone, 17-hydroxyprogesterone (17-OHP), testosterone (T), dehydroepiandrosterone, and SHBG were measured at 0 and 36 hours. RESULTS: Twenty-two women completed the study. In both normal-weight and obese women, peak serum concentration (Cmax), area under the curve (AUC), and average hCG concentration were higher after i.m. injection as compared with s.c. injection (all P < .003). Obese women had markedly lower Cmax, AUC, and average hCG concentration after s.c. injection as compared with normal-weight women (P = .02, P = .009, and P = .008, respectively). After i.m. injection, Cmax, AUC, and average concentration were similar for normal-weight and obese women (P = .31, P = .25, and P = .18, respectively). Thirty-six percent of obese women had muscular layers beyond the reach of a standard 1.5 inch needle. hCG caused a significant rise in 17-OHP in both obese and normal-weight women and an increase in T in obese but not normal-weight women (all P < .04). CONCLUSIONS: Subcutaneous injection yields lower hCG levels in obese women. Standard-length needles are insufficient to administer i.m. injections in many obese women.

Pharmacokinetics of eCG and induction of fertile estrus in bitches using eCG followed by hCG.

The aim was to design a protocol combining eCG followed by hCG for estrus induction in the bitch. In Experiment 1, three ovariohysterectomized bitches received 10 000 IU of eCG iv, and 15 days later 10 000 IU of eCG im. Blood samples were taken up to 144 h after each injection to measure eCG concentrations. In Experiment 2, 25 healthy, intact late anestrous bitches were assigned to one of five doses of eCG (5, 10, 15, 20, 44, or 50 IU/kg eCG im; [TRT5-TRT50]). Sexual behavior (SB), clinical signs of estrus (CSE) and vaginal cytology (VC) samples were obtained and scored before eCG administration and every other day until onset of estrus, or for 14 days. In Experiment 3, intact late anestrous bitches were assigned to a treatment group (TRT; n = 16) and received eCG (50 IU/kg im) followed by hCG (500 IU im) 7 days later; or to a placebo group (PLA; n = 8) where they received 1 mL saline solution im. All bitches that were induced in estrus were mated or AI with fresh semen. In Experiment 1, maximum observed concentration (C(max)) eCG were similar between im and iv routes (6.1 ± 0.9 vs. 8.6 ± 0.5 IU/mL, P > 0.08), whereas time for maximum observed concentration (T(max.)) was longer for im compared to iv routes (17.5 ± 0.5 vs. 11.6 ± 0.3 h, P < 0.01). The area under the curve (AUC) was similar for im and iv routes (P > 0.48), and eCG was detectable in serum for at least 144 h for both routes. In Experiment 2, 3 days or 3 to 5 days after treatment, all bitches in TRT50 had higher scores compared to TRT5-44 animals (P < 0.01). In TRT50, the mean interval from treatment to estrus was 4.0 ± 0.4 days. In Experiment 3, the mean interval from treatment to estrus was shorter in the TRT group compared to the PLA group (4.1 ± 3.3 vs. 68.5 ± 4.4 days, P < 0.01). The previous interestrus interval was similar for TRT and PLA groups (199.6 ± 7.2 vs. 197.5 ± 10.2 days), but the new interestrus interval was shorter for the TRT compared to the PLA group (164.0 ± 7.2 vs. 212.2 ± 10.2 days; treatment by interval interaction, P < 0.007). Serum P(4) concentrations increased on the first day of cytologic diestrus after treatment in bitches in TRT (0.7 ± 0.3 vs. 22.8 ± 4.2 ng/mL; P < 0.01); but did not change in PLA (P > 0.84). Ninety-four percent of animals were bred (15/16; AI, n = 7; natural mating, n = 8), and 80% (12/15) became pregnant. None of the bitches had any side effects from the eCG and hCG therapy. We concluded that 50 IU/kg of eCG combined 7 days later with 500 IU of hCG was effective to induce normal and fertile estrus in bitches at 164 days post estrus, with an 80% pregnancy rate, with no side effects, and with a reduction of 48 days of the interestrus interval.

Pharmacokinetics of human chorionic gonadotropin after i.m. administration in goats (Capra hircus).

The present investigation addresses the pharmacokinetics of human chorionic gonadotropin (hCG), intramuscularly (i.m.) administered to goats. Nine pluriparous does of the Boer goat breed, 2-6 years of age and weighing 45-60 kg, were administered 500 IU hCG (2 ml Chorulon) deep into the thigh musculature 18 h after superovulatory FSH treatment. Blood samples were drawn from the jugular vein at 2  h intervals for the first 24h, at 6 h intervals until 42 h, and at 12 h intervals until 114 h after administration. After centrifugation, plasma hCG concentrations were determined by electrochemiluminescence immunoassay. Pharmacokinetical parameters were as follows: lag time, 0.4 (s.e.m. 0.1) h; absorption rate constant, 0.34 (s.e.m. 0.002) h; absorption half-life, 2.7 (s.e.m. 0.5) h; elimination rate constant, 0.02 (s.e.m. 0.002) h; biological half-life, 39.4 (s.e.m. 5.1) h; and apparent volume of distribution, 16.9 (s.e.m. 4.3) l. The plasma hCG profile was characterized by an absorption phase of 11.6 (s.e.m. 1.8) h and an elimination phase of 70.0 (s.e.m. 9.8) h, with considerable individual variation in bioavailability and pharmacokinetical parameters. Biological half-life was negatively correlated (P<0.05) with peak concentration (r=-0.76), absorption rate constant (r=-0.78), and elimination rate constant (r=-0.87). The results indicate that after rapid absorption, hCG remains in the circulation for an extended period. This has to be taken into account when assessing the stimulatory response to hCG treatment on an ovarian level.

Current opinion on use of luteinizing hormone supplementation in assisted reproduction therapy: an Asian perspective.

LH and FSH have complementary functions in ensuring optimal oocyte maturation and ovulation. In women undergoing assisted reproduction technology protocols with gonadotrophin-releasing hormone analogues, LH and FSH concentrations are reduced. While FSH use in assisted reproduction technology is well established, there is no published consensus on the need for exogenous LH in Asian patients. Having reviewed the concept of the LH therapeutic window and differences between recombinant human LH (r-HLH) and human menopausal gonadotrophin, a consensus was reached on which patient subgroups may benefit from LH supplementation. Adjuvant r-HLH gives clinicians precise control over the dose of LH bioactivity administered to target the therapeutic window. The use of r-HLH is recommended in women with poor response in a previous cycle or suboptimal follicular progression in a current cycle by day 6-8 of stimulation. r-HLH should also be considered in women at risk of suboptimal response, specifically age > 35 years. Other risk markers that suggest the need for LH supplementation, which include baseline/day-6 serum LH and anti-Müllerian hormone concentrations, antral follicle count and LH polymorphisms require further research and verification. For measurement of LH response adequacy, the monitoring of follicular progression, oestradiol concentrations and endometrial thickness is recommended.

Evaluation of process efficiency and bioequivalence of biosimilar recombinant human chorionic gonadotropin (rhCG).

BACKGROUND: Human chorionic gonadotropin (hCG) is a therapeutic protein used for ovulation induction in women with infertility. Dong-A Pharm. Co. has developed recombinant hCG (rhCG) [product code DA-3803] produced in Chinese hamster ovary cells and evaluated its biologic properties, such as biologic potency, efficacy, and pharmacokinetic profile, compared with a reference product, Ovidrel®. OBJECTIVE: The purpose of this study was to evaluate the efficiency of the purification process of Dong-A rhCG (DA-3803) and its bioequivalence from a biosimilar perspective. METHODS: The efficiency of the purification process was estimated through scale-down clearance studies for viruses, endotoxins, host cell DNAs (HCDs) and host cell proteins (HCPs). To confirm bioequivalence, the in vivo/in vitro biologic potency, ovulation induction rate, and pharmacokinetic profile of DA-3803 were compared with those of Ovidrel®. RESULTS: In the clearance studies, the lowest log reduction value (LRV) for model viruses was 8.43. LRVs for endotoxins, HCDs, and HCPs were greater than 5.27, 16.36, and 3.37, respectively. DA-3803 showed equivalent potency with Ovidrel®, and similarity between DA-3803 and Ovidrel® was observed in an efficacy evaluation that measured ovulation induction. The bioequivalence was also confirmed in a rat pharmacokinetic study, which compared pharmacokinetic parameters such as maximum serum concentration, area under the concentration-time curve, time to reach maximum serum concentration, and half-life. In a comparison of different isoform groups of DA-3803, it was shown that the potency and pharmacokinetic profile depend on the sialic acid content. CONCLUSION: The purification process of DA-3803 was effective in removing the major process impurities, and DA-3803 showed similar biologic properties to the reference drug, Ovidrel®.

Predictive values of hCG clearance for risk of methotrexate resistance in low-risk gestational trophoblastic neoplasias.

BACKGROUND: Early identification of patients at high risk for chemoresistance among those treated with methotrexate (MTX) for low-risk gestational trophoblastic neoplasia (GTN) is needed. We modeled human chorionic gonadotropin (hCG) decline during MTX therapy using a kinetic population approach to calculate individual hCG clearance (CL(hCG)) and assessed the predictive value of CL(hCG) for MTX resistance. PATIENTS AND METHODS: A total of 154 patients with low-risk GTN treated with 8-day MTX regimen were retrospectively studied. NONMEM was used to model hCG decrease equations between day 0 and day 40 of chemotherapy. Receiver operating characteristic curve analysis defined the best CL(hCG) threshold. Univariate/multivariate survival analyses determined the predictive value of CL(hCG) and compared it with published predictive factors. RESULTS: A monoexponential equation best modeled hCG decrease: hCG(t) = 3900 x e(-0.149 x t). Median CL(hCG) was 0.57 l/day (quartiles: 0.37-0.74). Only choriocarcinoma pathology [yes versus no: hazard ratio (HR) = 6.01; 95% confidence interval (CI) 2.2-16.6; P < 0.001] and unfavorable CL(hCG) quartile (< or =0.37 versus >0.37 l/day: HR = 6.75; 95% CI 2.7-16.8; P < 0.001) were significant independent predictive factors of MTX resistance risk. CONCLUSION: In the second largest cohort of low-risk GTN patients reported to date, choriocarcinoma pathology and CL(hCG) < or =0.37 l/day were major independent predictive factors for MTX resistance risk.

Open labeled, uncontrolled pharmacokinetic study of a single intramuscular hCG dose in healthy male volunteers.

The current study was designed to compare blood and cerebrospinal fluid (CSF) pharmacokinetic characteristics of two forms of human chorionic gonadotropin (hCG): Pregnyl(R), derived from human urine, and Ovitrelle(R) a recombinant form. Two separate groups, each with six older male human subjects, were dosed with either form of the drug at 10,000 IU intramuscularly (IM), and followed over a 36-hour period. No significant difference in the serum level of hCG was observed for either preparation of hCG (Peak serum conc.: 316 +/- 53 vs. 270 +/- 60 at 12 hours, 311 +/- 38 vs. 321 +/- 60 IU/l at 24 hours; AUC: 10,053 +/- 1,268 vs. 8,793 +/- 1,768, Pregnyl and Ovitrelle, mean +/- SD, respectively). Additionally, both forms of circulating hCG distributed to the central nervous system (CNS) as manifest by an increased number of subjects whose CSF samples showed detectable levels of hCG in their CSF over a 36-hour period. Similarly, there was no significant difference between the two forms when distribution to the CSF was compared at 36 hours (2.0 and 1.2 IU/l; range 1.9 - 2.1 and 1 - 1.4 IU/l for Pregnyl and Ovitrelle, resp.). This preliminary study in normal human volunteers suggests that the two forms of hCG tested, Ovitrelle(R) and Pregnyl(R), when administered IM, distribute in a similar fashion into the circulation and CSF. Consequently, we conclude that these two drugs demonstrate no statistical significant difference with respect to the CSF.

A co-culture system reveals the involvement of intercellular pathways as mediators of the lutropin receptor (LHR)-stimulated ERK1/2 phosphorylation in Leydig cells.

Co-cultures of lutropin receptor (LHR) positive and negative Leydig cells were used to test the hypothesis that the LHR provokes phosphorylation of the extracellular regulated kinases (ERK1/2) using intracellular and intercellular pathways. Addition of hCG to MA-10 cells (LHR positive) stimulates phosphorylation of the EGF receptor (EGFR) and ERK1/2 whereas addition of hCG to I-10 cells (LHR negative) does not. Addition of hCG to co-cultures of MA-10 and I-10 cells rapidly stimulates the phosphorylation of the EGFR and ERK1/2 in I-10 cells, however. Transfection of interfering constructs shows that the LHR-mediated activation of Fyn in MA-10 cells is necessary for the phosphorylation of the EGFR and ERK1/2 in I-10 cells. This pathway can also be demonstrated in MA-10 cells but the phosphorylation of ERK1/2 in MA-10 cells also involves a second pathway mediated by protein kinase A (PKA). We propose that the LHR-mediated stimulation of the ERK1/2 cascade in Leydig cells depends on two independent pathways. One is intracellular and is mediated by PKA. The second is mediated by Fyn and it involves the release of soluble factors that act to phosphorylate the EGFR in an autocrine/paracrine fashion.

Relationship between serum human chorionic gonadotrophin levels and body mass index in women undergoing in vitro fertilisation cycles.

OBJECTIVE: To ascertain if serum concentrations following injection of human chorionic gonadotropin (hCG) influenced the outcome of in vitro fertilisation (IVF) treatment and correlated to body mass index (BMI). STUDY DESIGN: A prospective study conducted with the participation of 149 women undergoing IVF and/or intracytoplasmic sperm injection (ICSI) treatment at the regional IVF Unit in Liverpool, UK. The BMI of each individual was calculated and serum hCG concentrations were measured at 12 and 36 h following a subcutaneously (SC) injection of 5000 IU hCG. The main outcome measures were fertilisation rate and biochemical pregnancy rate. RESULTS: No correlation was found between serum hCG levels at 12 and 36 h with the number of oocytes retrieved or the number of oocytes fertilised. Furthermore, there was no correlation between BMI and hCG levels at 12 and 36 h following administration (Pearson's correlation coefficient: -0.23, -0.24, respectively). CONCLUSION: Our results suggest that the serum concentrations of hCG do not influence IVF outcome and that the serum levels of hCG achieved following administration do not correlate with the individual's BMI. Serum hCG concentration also does not correlate with number of oocytes collected or fertilisation rate.

A constitutively active mutant of the human lutropin receptor (hLHR-L457R) escapes lysosomal targeting and degradation.

Using biochemical and imaging approaches, we examined the postendocytotic fate of the complex formed by human choriogonadotropin (hCG) and a constitutively active mutant of the human lutropin receptor (hLHR-L457R) found in a boy with precocious puberty and Leydig cell hyperplasia. After internalization, some of the complex formed by the hLHR-wild type (hLHR-wt) and hCG recycles to the cell surface, and some is found in lysosomes where the hormone is degraded. In contrast, the complex formed by the hLHR-L457R and hCG is not routed to the lysosomes, most of it is recycled to the cell surface and hormone degradation is barely detectable. For both, hLHR-wt and -L457R, there is an hCG-induced loss of cell surface receptors that accompanies internalization but this loss cannot be prevented by leupeptin. The removal of recycling motifs of the hLHR by truncation of the C-terminal tail at residue 682 greatly enhances the lysosomal accumulation of the hormone-receptor complexes formed by the hLHR-wt or the L457R mutant, the degradation of the internalized hormone, and the loss of cell surface receptors. The degradation of the hormone internalized by these mutants as well as the loss of cell surface receptors is largely prevented by leupeptin. These results highlight a previously unrecognized complexity in the postendocytotic trafficking of the hLHR and document a clear difference between the properties of the constitutively active mutant and the agonist-activated hLHR-wt. This lack of lysosomal degradation of the L457R mutant could contribute to its constitutive activity by prolonging the duration of signaling.

Endometrial, subendometrial, and ovarian stromal blood flow in patients treated with two different doses of recombinant human chorionic gonadotropin.

The effects of two different doses of recombinant hCG on blood flow to the uterus and ovary on the day of oocyte retrieval were studied by three-dimensional Doppler ultrasonography in 60 women during IVF treatment. There were no differences in all the indices of endometrial, subendometrial, and ovarian stromal blood flow in women who had received 250 microg or 500 microg of recombinant hCG for final oocyte maturation.

Comparative use of urinary and recombinant human chorionic gonadotropins in women.

Human chorionic gonadotropin (hCG) preparations have been widely used as a surrogate for the mid-cycle luteinizing hormone (LH) surge for several decades. The urinary source of hCG preparations was favored for many years because of the easy collection of the starting material. However, the final structure of these urinary-derived preparations appears to be quite different from the natural placenta product. Furthermore, many disadvantages of these commercial preparations have been reported, such as local adverse events and immunologic reactions. The recent advent of recombinant DNA technology has now made recombinant hCG (r-hCG) available. This new product ensures high purity and batch-to-batch consistency. The pharmacokinetic and pharmacodynamic profiles of both urinary and recombinant preparations are quite similar. In clinical practice, several trials have been performed to compare both the efficacy and safety of urinary hCG (u-hCG) and r-hCG preparations. Overall, the reported data show that r-hCG preparations are at least as effective as u-hCG products in reproducing the follicular events surrounding the endogenous LH surge. Moreover, the r-hCG products ensure a better hormonal environment during the luteal phase. Finally, the overall tolerability of r-hCG preparations has been shown to be much better than that of u-hCG preparations. As a consequence, the newly available r-hCG preparations offer the first opportunity for clinicians to treat anovulatory women with a full range of recombinant products.

The bioequivalence of liquid and freeze-dried formulations of recombinant human chorionic gonadotrophin.

OBJECTIVE: To compare the bioavailability and tolerability of liquid and freeze-dried formulations of recombinant human chorionic gonadotrophin (r-hCG). SUBJECTS AND METHODS: In an open-label, randomised, single-centre, Phase I study, healthy adult volunteers (18-50 years of age) received single injections of r-hCG 250 microg from reconstituted freeze-dried (1.0 mL of 250 microg/mL) and liquid (0.5 mL of 250 microg/0.5 mL) formulations in random order, separated by a 10-day wash-out period. Pharmacokinetics (C(max), AUC, AUC(last), t(max)) and local and systemic tolerability were assessed. RESULTS: Pharmacokinetic properties of the two formulations were very similar, with mean C(max) 125 mIU/mL (liquid formulation) vs 129 mIU/mL (freeze-dried formulation), mean AUC 10,350 mIU.h/mL vs 10,480 mIU(.)h/mL, mean AUC(last) 10,050 mIU.h/mL vs 10,210 mIU.h/mL, and median t(max) 20 vs 24h. The 90% confidence intervals of the ratios of the treatment means for C(max), AUC and AUC(last) all fell within the pre-defined FDA acceptance range of 0.8-1.25, demonstrating the bioequivalence of the two formulations. Both formulations were equally well tolerated; the most frequent adverse events were headache and nausea. CONCLUSION: The liquid formulation of r-hCG was shown to be bioequivalent to the freeze-dried formulation, with no clinically significant differences in tolerability. The liquid formulation of r-hCG can be expected to provide the same efficacy and tolerability as the freeze-dried formulation when used to trigger final follicular maturation in women undergoing therapies for assisted reproduction, together with a greater convenience of use.

Fast renal trapping of porcine luteinizing hormone (pLH) shown by 123I-scintigraphic imaging in rats explains its short circulatory half-life.

BACKGROUND: Sugar moieties of gonadotropins play no primary role in receptor binding but they strongly affect their circulatory half-life and consequently their in vivo biopotencies. In order to relate more precisely hepatic trapping of these glycoproteic hormones with their circulatory half-life, we undertook a comparative study of the distribution and elimination of porcine LH (pLH) and equine CG (eCG) which exhibit respectively a short and a long half-life. This was done first by following half-lives of pLH in piglets with hepatic portal circulation shunted or not. It was expected that such a shunt would enhance the short half-life of pLH. Subsequently, scintigraphic imaging of both 123I-pLH and 123I-eCG was performed in intact rats to compare their routes and rates of distribution and elimination. METHODS: Native pLH or eCG was injected to normal piglets and pLH was tested in liver-shunted anaesthetized piglet. Blood samples were recovered sequentially over one hour time and the hormone concentrations were determined by a specific ELISA method. Scintigraphic imaging of 123I-pLH and 123I-eCG was performed in rats using a OPTI-CGR gamma camera. RESULTS: In liver-shunted piglets, the half-life of pLH was found to be as short as in intact piglets (5 min). In the rat, the half-life of pLH was also found to be very short (3-6 min) and 123I-pLH was found to accumulate in high quantity in less than 10 min post injection at the level of kidneys but not in the liver. 123I-eCG didn't accumulate in any organ in the rats during the first hour, plasma concentrations of this gonadotropin being still elevated (80%) at this time. CONCLUSION: In both the porcine and rat species, the liver is not responsible for the rapid elimination of pLH from the circulation compared to eCG. Our scintigraphic experiments suggest that the very short circulatory half-life of LH is due to rapid renal trapping.