Investigation of luteal HCG supplementation in GnRH-agonist-triggered fresh embryo transfer cycles: a randomized controlled trial

RESEARCH QUESTION

Does splitting the human chorionic gonadotrophin (HCG) support in IVF cycles triggered by a gonadotrophin-releasing hormone agonist result in a better progesterone profile?

DESIGN

Randomized controlled three-arm study, performed at the Fertility Clinic, Odense University Hospital, Denmark. Patients with 12-25 follicles ≥12 mm were randomized into three groups: Group 1 - ovulation triggered with 6500 IU HCG; Group 2 - ovulation triggered with 0.5 mg GnRH agonist, followed by 1500 IU HCG on the day of oocyte retrieval (OCR); and Group 3 - ovulation triggered with 0.5 mg GnRH agonist, followed by 1000 IU HCG on the day of OCR and 500 IU HCG on OCR + 5. All groups received 180 mg vaginal progesterone. Progesterone concentrations were analysed in eight blood samples from each patient.

RESULTS

Sixty-nine patients completed the study. Baseline and laboratory data were comparable. Progesterone concentration peaked on OCR + 4 in Groups 1 and 2, and peaked on OCR + 6 in Group 3. On OCR + 6, the progesterone concentration in Group 2 was significantly lower compared with Groups 1 and 3 (P = 0.003 and P < 0.001, respectively). On OCR + 8, the progesterone concentration in Group 3 was significantly higher compared with the other groups (both P<0.001). Progesterone concentrations were significantly higher in Group 3 from OCR + 6 until OCR + 14 compared with the other groups (all P ≤ 0.003). Four patients developed ovarian hyperstimulation syndrome in Group 3.

CONCLUSION

Sequential HCG support after a GnRH agonist trigger provides a better progesterone concentration in the luteal phase.

P-681 Will the hCG trigger dose used for final oocyte maturation in IVF impact endogenous progesterone during the luteal phase? - A randomized controlled trial

Study question

Is there an association between the hCG dose used for ovulation trigger and the endogenous progesterone production during the luteal phase?

Summary answer

Increased hCG dosing significantly increased the endogenous progesterone level during the luteal phase.

What is known already

During the luteal phase of an IVF treatment, the endogenous progesterone (P4) production is negatively impacted due to reduced circulating endogenous LH, caused by negative feed-back of elevated steroids; thus, luteal phase support (LPS) with exogenous P4 remains mandatory in IVF. Apart from inducing final oocyte maturation, the gold standard HCG trigger also functions as an early LPS, boosting P4 production by the corpora lutea (CL). P4 plays a pivotal role for embryo implantation and pregnancy, and an optimal P4 level around peri-implantation seems to be essential for the reproductive outcomes of fresh and frozen/thaw embryo transfer cycles.

Study design, size, duration

A randomized controlled 4-arm study, including a total of 127 IVF patients, enrolled from January 2015 until September 2019 at the Fertility Clinic, Odense University Hospital, Denmark.

Participants/materials, setting, methods

IVF patients with ≤ 11 follicles ≥ 12 mm were randomized to four groups. Groups 1-3 were triggered with: 5.000 IU, 6.500 IU or 10.000 IU, hCG, respectively, receiving a LPS consisting of 17-α-hydroxy-progesterone (17α OH P4) to distinguish the endogenous P4 from the exogenous supplementation. Group 4 (control) was randomized to a 6.500 IU hCG trigger and standard LPS. A total of eight blood samples were drawn during the early luteal phase.

Main results and the role of chance

A total of 94 patients completed the study: 21, 22, 25 and 26 patients in each group, respectively. Baseline characteristics were similar, except for the endogenous LH level and cycle lengths. There were no significant differences between groups regarding ovarian stimulation, number of oocytes and embryos. The median number of follicles ≥ 12mm on the day of trigger was 8.5, resulting in 6.6 oocytes being retrieved. Significant differences in P4 levels were seen at OPU+8 (p &lt; 0.001), OPU+10 (p &lt; 0.001) and OPU+14 (p &lt; 0.001), with positive correlations between P4 level and hCG dose. Groups compared individually showed significant difference in P4 between low and high trigger dose at OPU+4 group 1 and 3 (p = 0.037) and OPU+8 group 1 and 3 (p = 0.007) and between all the three groups around implantation at OPU+6 group 1 and 2 (p = 0.011), group 2 and 3 (p = 0.042) and group 1 and 3 (p &lt; 0.001). Higher P4 levels around implantation were related to follicle count and to pregnancy. After logistic regression analyses there were still significant individual differences between the groups.

Limitations, reasons for caution

Although patients were randomized and strict inclusion and exclusion criteria were used, the RCT was un-blinded, including a relatively small number of patients. Moreover, for dosing purposes urinary hCG as well as recombinant hCG was used and pharmacokinetics differ. Finally, the P4 level could be influenced by circadian fluctuations.

Wider implications of the findings

This is the first study to explore dose-responses in circulating P4 after hCG trigger in IVF patients. Increasing the hCG trigger dose increased the endogenous P4 around peri-implantation. Personalizing the hCG trigger dose could be a key point to secure the most optimal P4 mid-luteal phase P4 level.

Trial registration number

Eudract 2013-003304-39

P–681 Will the hCG trigger dose used for final oocyte maturation in IVF impact endogenous progesterone during the luteal phase? - A randomized controlled trial

Study question

Is there an association between the hCG dose used for ovulation trigger and the endogenous progesterone production during the luteal phase?

Summary answer

Increased hCG dosing significantly increased the endogenous progesterone level during the luteal phase.

What is known already

During the luteal phase of an IVF treatment, the endogenous progesterone (P4) production is negatively impacted due to reduced circulating endogenous LH, caused by negative feed-back of elevated steroids; thus, luteal phase support (LPS) with exogenous P4 remains mandatory in IVF. Apart from inducing final oocyte maturation, the gold standard HCG trigger also functions as an early LPS, boosting P4 production by the corpora lutea (CL). P4 plays a pivotal role for embryo implantation and pregnancy, and an optimal P4 level around peri-implantation seems to be essential for the reproductive outcomes of fresh and frozen/thaw embryo transfer cycles.

Study design, size, duration

A randomized controlled 4-arm study, including a total of 127 IVF patients, enrolled from January 2015 until September 2019 at the Fertility Clinic, Odense University Hospital, Denmark.

Participants/materials, setting, methods

IVF patients with ≤ 11 follicles ≥ 12 mm were randomized to four groups. Groups 1–3 were triggered with: 5.000 IU, 6.500 IU or 10.000 IU, hCG, respectively, receiving a LPS consisting of 17-α-hydroxy-progesterone (17α OH P4) to distinguish the endogenous P4 from the exogenous supplementation. Group 4 (control) was randomized to a 6.500 IU hCG trigger and standard LPS. A total of eight blood samples were drawn during the early luteal phase.

Main results and the role of chance

A total of 94 patients completed the study: 21, 22, 25 and 26 patients in each group, respectively. Baseline characteristics were similar, except for the endogenous LH level and cycle lengths. There were no significant differences between groups regarding ovarian stimulation, number of oocytes and embryos. The median number of follicles ≥ 12mm on the day of trigger was 8.5, resulting in 6.6 oocytes being retrieved. Significant differences in P4 levels were seen at OPU+8 (p &lt; 0.001), OPU+10 (p &lt; 0.001) and OPU+14 (p &lt; 0.001), with positive correlations between P4 level and hCG dose. Groups compared individually showed significant difference in P4 between low and high trigger dose at OPU+4 group 1 and 3 (p = 0.037) and OPU+8 group 1 and 3 (p = 0.007) and between all the three groups around implantation at OPU+6 group 1 and 2 (p = 0.011), group 2 and 3 (p = 0.042) and group 1 and 3 (p &lt; 0.001). Higher P4 levels around implantation were related to follicle count and to pregnancy. After logistic regression analyses there were still significant individual differences between the groups.

Limitations, reasons for caution

Although patients were randomized and strict inclusion and exclusion criteria were used, the RCT was un-blinded, including a relatively small number of patients. Moreover, for dosing purposes urinary hCG as well as recombinant hCG was used and pharmacokinetics differ. Finally, the P4 level could be influenced by circadian fluctuations.

Wider implications of the findings: This is the first study to explore dose-responses in circulating P4 after hCG trigger in IVF patients. Increasing the hCG trigger dose increased the endogenous P4 around peri-implantation. Personalizing the hCG trigger dose could be a key point to secure the most optimal P4 mid-luteal phase P4 level.

Trial registration number

Eudract 2013–003304–39

The Danish National Register of assisted reproductive technology: content and research potentials

The Danish National Register of assisted reproductive technology (ART) was initially established in 1994. The register comprises complete information on all ART procedures in public and private clinics in Denmark from 2013 and onwards, including baseline information on the cause of infertility and a number of health-related patient characteristics. The register enables monitoring and research on infertility treatment and reproductive topics in single women or couples seeking assisted reproduction, and the register is thus a key component of the Danish health information system within human reproduction. We aimed to provide an updated description of the register including advantages and pitfalls when using the register for reproductive epidemiological research, and a description of the accessibility for researchers. The Danish ART register is a valuable tool for epidemiological research. However, the inherent strengths and limitations ought to be in perspective when designing studies and interpreting the study results. Reports with annually aggregated data on ART treatments, can be accessed on the Danish Health Data Authority web page and researchers may obtain access to individual pseudonomized data via secure servers at the Danish Health Data Authority and Statistics Denmark.

Ovulation before or after intrauterine insemination does not affect live birth rates: a retrospective cohort study of 6701 cycles

RESEARCH QUESTION

Should intrauterine insemination be carried out before or after follicle rupture, and is there a difference in sex ratio, according to follicle rupture at the time of insemination?

DESIGN

In this retrospective cohort study conducted at the Fertility Clinic, Odense University Hospital, Denmark, data from 6701 homologous insemination cycles were analysed. Follicle rupture was determined by transvaginal ultrasonography at the time of insemination. The pregnancy rate, clinical pregnancy rate (CPR) and live birth rate (LBR) were recorded.

RESULTS

In 2831 cycles (42.2%), follicle rupture had occurred at the time of insemination, whereas, in 3870 cycles (57.8%), no follicle rupture had occurred at the time of insemination. Overall, 1186 (17.7%) cycles resulted in a positive pregnancy test and no significant differences were found in pregnancy rate between rupture and no rupture of follicle (17.8% versus 17.7%, P = 0.90). Follicle rupture before or after insemination did not affect CPR (14.8% versus 15.0%, P = 0.86) or LBR (11.9% versus 12.2%, P = 0.75) per cycle. Moreover, the sex ratio of children born did not depend on follicle rupture (P = 0.20). After logistic regression with cluster and adjusting for baseline characteristics, no significant differences between groups were observed.

CONCLUSION

Ovulation at the time of insemination is not associated with pregnancy rate, CPR, LBR or gender.

Mid-Luteal 17-OH Progesterone Levels in 614 Women Undergoing IVF-Treatment and Fresh Embryo Transfer-Daytime Variation and Impact on Live Birth Rates

Introduction: Corpus luteum (CL) produces progesterone (P₄) and 17-OH progesterone (17-OH P₄) during the luteal phase. Contrary to P₄, 17-OH P₄ is not supplied as part of the luteal phase support following IVF-treatment. Therefore, measuring endogenous serum 17-OH P₄ levels may more accurately reflect the CL function compared to monitoring serum P₄ concentrations. Objective: To explore the correlation between mid-luteal serum 17-OH P₄ levels and live birth rates and to explore the possible daytime variations in mid-luteal serum 17-OH P_4. Design: Prospective cohort study. Patients: 614 women undergoing IVF-treatment and fresh embryo transfer. Intervention: All patients had serum 17-OH P₄ measured 7 days after oocyte pick-up (OPU+7). Furthermore, on OPU+7, seven patients underwent repeated blood sampling during daytime to clarify the endogenous daytime secretory pattern of 17-OH P₄. Outcome measure: Live birth rate. Secondary outcome measure: Daytime variation in serum 17-OH P₄ levels. Results: The highest chance of a live birth was seen with mid-luteal 17-OH P₄ between 6.0 and 14.0 nmol/l. The chance of a live birth was reduced below (RD -10%, p = 0.07), but also above the optimal range for 17-OH P₄ (RD -12%, p = 0.04). Patients with diminished CL-function (17-OH P₄ < 6 nmol/l) displayed clinically stable 17-OH P₄ values, whereas patients with 17-OH P₄ levels >6 nmol/l showed random 17-OH P₄ fluctuations during daytime. Conclusion: The association between 17-OH P₄ and reproductive outcomes is non-linear, and the negative effect of excessive CL-secretion seems to be just as strong as the negative effect of a reduced CL-function during the peri-implantation period.

Assisted reproductive technology in Europe, 2011: results generated from European registers by ESHRE

STUDY QUESTION

The 15th European IVF-monitoring (EIM) report presents the results of treatments involving assisted reproductive technology (ART) initiated in Europe during 2011: are there any changes in the trends compared with previous years?

SUMMARY ANSWER

Despite some fluctuations in the number of countries reporting data, while the overall number of ART cycles has continued to increase year by year, the pregnancy rates in 2011 decreased slightly to those reported in 2010, and the number of transfers with multiple embryos (3+) and the multiple delivery rates declined.

WHAT IS KNOWN ALREADY

Since 1997, ART data in Europe have been collected and reported in 14 manuscripts, published in Human Reproduction.

STUDY DESIGN, SIZE, DURATION

Retrospective data collection of European ART data by the EIM Consortium for the European Society of Human Reproduction and Embryology (ESHRE); cycles started between 1 January and 31 December 2011 are collected on a yearly basis. The data are collected by National Registers, when existing, or on a voluntary basis by personal information.

PARTICIPANTS/MATERIALS SETTING, METHODS

From 33 countries (+2 compared with 2010), 1064 clinics reported 609 973 treatment cycles including: IVF 138 592, ICSI 298 918, frozen embryo replacement (FER) 129 693, egg donation (ED) 30 198, in vitro maturation 511, preimplantation genetic diagnosis/screening 6824 and frozen oocyte replacements 5237. European data on intrauterine insemination (IUI) using husband/partner's semen (IUI-H) and donor semen (IUI-D) were reported from 861 IUI laboratories in 24 countries. A total of 174 390 IUI-H and 41 151 IUI-D cycles were included.

MAIN RESULTS AND THE ROLE OF CHANCE

In 17 countries where all clinics reported to the ART register, a total of 361 972 ART cycles were performed in a population of 285 million inhabitants, corresponding to 1269 cycles per million inhabitants. For all IVF cycles, the clinical pregnancy rates per aspiration and per transfer were stable with 29.1 and 33.2%, respectively, and for ICSI, the corresponding rates also were stable with 27.9 and 31.8%, respectively. In FER cycles, the pregnancy rate per thawing increased to 21.3% if compared with previous years. In ED cycles, the pregnancy rate per fresh transfer decreased to 45.8% (47.4% in 2010) and increased to 33.6% (33.3% in 2010) per thawed transfer. The delivery rate after IUI-H decreased to 8.3 (8.9 in 2010), and to 12.2% (13.8% in 2010) after IUI-D. In IVF and ICSI cycles, 1, 2, 3 and 4+ embryos were transferred in 27.5, 56.7, 14.5 and 1.3% of cycles, respectively. The proportions of singleton, twin and triplet deliveries after IVF and ICSI (added together) were 80.8, 18.6 and 0.6%, respectively, resulting in a total multiple delivery rate of 19.2% compared with 20.6% in 2010, 20.2% in 2009, 21.7% in 2008, 22.3% in 2007 and 20.8% in 2006. In FER cycles, the multiple delivery rate was 13.2% (12.8% twins and 0.4% triplets). Twin and triplet delivery rates associated with IUI cycles were 9.7/0.6% and 7.3/0.3%, following IUI-H and IUI-D treatment, respectively.

LIMITATIONS, REASONS FOR CAUTION

The method of reporting varies among countries, and registers from a number of countries have been unable to provide some of the relevant data such as initiated cycles and deliveries. As long as data are incomplete and generated through different methods of collection, results should be interpreted with caution.

WIDER IMPLICATIONS OF THE FINDINGS

The 15th ESHRE report on ART shows a continuing expansion of the number of treatment cycles in Europe, with more than 600 000 cycles reported in 2011. Since 2006, the proportion of IVF to ICSI cycles has reached a plateau after a small decrease in 2009. Pregnancy and delivery rates after IVF remained relatively stable compared with 2010 and 2009. The pregnancy rate per aspiration in ICSI cycles declined for the first time by 0.9%. The multiple delivery rate is lower than ever before.

STUDY FUNDING/COMPETING INTERESTS

The study had no external funding; all costs are covered by ESHRE. There are no competing interests.

GEBR-7b, a novel PDE4D selective inhibitor that improves memory in rodents at non-emetic doses

BACKGROUND AND PURPOSE

Strategies designed to enhance cerebral cAMP have been proposed as symptomatic treatments to counteract cognitive deficits. However, pharmacological therapies aimed at reducing PDE4, the main class of cAMP catabolizing enzymes in the brain, produce severe emetic side effects. We have recently synthesized a 3-cyclopentyloxy-4-methoxybenzaldehyde derivative, structurally related to rolipram, and endowed with selective PDE4D inhibitory activity. The aim of the present study was to investigate the effect of the new drug, namely GEBR-7b, on memory performance, nausea, hippocampal cAMP and amyloid-β (Aβ) levels.

EXPERIMENTAL APPROACH

To measure memory performance, we performed object recognition tests on rats and mice treated with GEBR-7b or rolipram. The emetic potential of the drug, again compared with rolipram, was evaluated in rats using the taste reactivity test and in mice using the xylazine/ketamine anaesthesia test. Extracellular hippocampal cAMP was evaluated by intracerebral microdialysis in freely moving rats. Levels of soluble Aβ peptides were measured in hippocampal tissues and cultured N2a cells by elisa.

KEY RESULTS

GEBR-7b increased hippocampal cAMP, did not influence Aβ levels and improved spatial, as well as object memory performance in the object recognition tests. The effect of GEBR-7b on memory was 3 to 10 times more potent than that of rolipram, and its effective doses had no effect on surrogate measures of emesis in rodents.

CONCLUSION AND IMPLICATIONS

Our results demonstrate that GEBR-7b enhances memory functions at doses that do not cause emesis-like behaviour in rodents, thus offering a promising pharmacological perspective for the treatment of memory impairment.

Olfactory bulb volume and olfactory function in patients with multiple sclerosis

BACKGROUND

Some studies reported olfactory dysfunction in patients with multiple sclerosis (MS). There is no agreement about the most suitable testing method for measuring olfactory function (OF) in MS patients. Recent studies showed that olfactory bulb volume changes with the degree of olfactory dysfunction. We assessed olfactory bulb volume of MS patients with magnetic resonance imaging (MRI) and related it to the OF.

MATERIAL AND METHODS

Volumetric measurements of the right and left olfactory bulb (OB) were performed by manual segmentation within 36 MS patients. Psychophysical testing of the orthonasal OF was performed using threshold-discrimination-identification (TDI) score in MS patients.

RESULTS

Of all MS patients, 44.4% displayed olfactory dysfunction. The TDI score of all 36 MS patients, especially the score of the Identification subtest correlated strongly with neurological scores typical of MS. In patients with a decreased OB volume, there was a positive correlation between volumetry of the OB and OF.

CONCLUSION

OB volumes may provide valuable information about MS patients with olfactory dysfunction. The TDI test and Identification subtest were very sensitive in detecting olfactory dysfunction in MS patients.

[Pathological changes of the chemosensory function in multiple sclerosis - an MRI study]

PURPOSE

To examine possible causes for olfactory and gustatory dysfunction in MS patients in a prospective study with MRI.

MATERIALS AND METHODS

30 MS patients (21 women, 11 men, 22 - 65 years, Ø 42 years) were examined by MRI. The olfactory bulb (OB) and olfactory brain volume was correlated with the number and volume of MS lesions in the olfactory brain and the non-olfactory brain. Olfactory testing was performed using the Threshold-Discrimination-Identification Test (TDI), and gustatory function was tested using the Taste-Strips-Test (TST).

RESULTS

33 % of the MS patients displayed olfactory dysfunction (8 % of the control group), and 17 % displayed gustatory dysfunction (5 % of the control group). There was a correlation between the olfactory brain volume and the number (r = -0.38, p < 0.05) and volume (r = -0.38, p < 0.05) of MS lesions in the olfactory brain. The olfactory brain volume correlated with the number of MS lesions in the non-olfactory brain (r = -0.48, p < 0.05). The volume of the left OB correlated with the volume of MS lesions in the olfactory brain (r = -0.42, p < 0.05), the number (r = 0.37, p < 0.05) and volume (r = 0.4, p < 0.05) of lesions in the left part of the olfactory brain and with the TST score (r = -0.45, p < 0.05). The TST score correlated with the volume of lesions in the left (r = -0.45, p < 0.05) and right part (r = -0.53, p < 0.05) of the olfactory brain. The TST score correlated with the number of lesions in the non-olfactory brain (r = -0.48, p < 0.05).

CONCLUSION

The correlation between a higher number and volume of MS lesions in the olfactory brain with a decreased OB and olfactory brain volume could help to explain olfactory and gustatory dysfunction in MS patients. Just the left OB correlated with the number and volume of lesions in the olfactory brain. Manual segmentation was a suitable method for measuring OB and olfactory brain volume.

Effects of recombinant LH treatment on folliculogenesis and responsiveness to FSH stimulation

BACKGROUND

The role of LH in sensitizing antral follicles to FSH is unclear. LH is required for normal hormone production and normal oocyte and embryo development, but follicular responses to LH may depend upon the stage of development. Potential roles at the early follicular phase were explored in a clinical setting by employing a sequential approach to stimulation by recombinant human (r-h) LH followed by r-hFSH in women who were profoundly down-regulated by depo GnRH agonist.

METHODS

We employed a multi-centre, prospective, randomized approach. Women (n = 146) were treated in a long course high-dose GnRH agonist (Decapeptyl, 4.2 mg s.c.) protocol and were randomized to receive r-hLH (Luveris, 300 IU/day) for a fixed 7 days, or no r-hLH treatment. This was followed by a standard r-hFSH stimulation regime (Gonal-F, 150 IU/day). Ultrasound and hormone assessments of responses were measured at the start of r-hLH treatment, on FSH stimulation Days 0 and 8 and at the time of HCG administration.

RESULTS

The LH treatment was associated with increased small antral follicles prior to FSH stimulation (P = 0.007), and an increased yield of normally fertilized (2 PN) embryos (P = 0.03). There was no influence of the r-hLH pretreatment upon hormone profiles or ultrasound assessments during the FSH phase. Anti-mullerian hormone increased in both groups during the week prior to FSH stimulation (P = 0.002).

CONCLUSIONS

This sequential approach to the use of r-hLH in standard IVF showed a possible modest clinical benefit. The results support other recent work exploring up-regulated androgen drive upon follicular metabolism indicating that clinical benefit may be obtainable after further practical explorations of the concept.

Malformation rate and sex ratio in 412 children conceived with epididymal or testicular sperm

BACKGROUND

Follow-up studies of children conceived after ICSI using epididymal or testicular sperm are important due to a still more extensive use of immature male germ cells for ICSI. It is, however, difficult to evaluate the potential risks of malformations of children born after ICSI, overcoming the natural fertilization processes, due to methodological limitations.

METHODS

Follow-up study including all children born in Denmark and Norway following ICSI in Denmark, using epididymal or testicular sperm, was done. A questionnaire was sent to the parents between 3 months and 7 years after delivery.

RESULTS

Of 341 couples, 329 returned the questionnaire giving a response rate of 96.5%. The study included 412 children, 225 girls and 187 boys, giving a sex ratio (males/males + females) of 45.4% compared with 53.1% in Danish children conceived after conventional IVF without ICSI (P < 0.005). Among a total of 14 (3.4%; 95% confidence interval (CI): 1.9%-5.7%) major malformations, three boys with hypospadias were the most remarkable finding (1.6%; 95% CI: 0.33-4.7%).

CONCLUSIONS

An increased frequency of hypospadias in the male offsprings was seen compared with the general population. Apart from this, no increased major malformation rate was detected in ICSI children conceived with epididymal or testicular sperm when compared with malformation rates for IVF or spontaneously conceived children reported in the literature. The sex ratio was significantly lower for ICSI children conceived with epididymal or testicular sperm when compared with children conceived with conventional IVF.

Register data on assisted reproductive technology (ART) in Europe including a detailed description of ART in Denmark

The European Society for Human Reproduction and Embryology (ESHRE) has monitored Assisted Reproduction in Europe since 1997. In 2001, 579 clinics from 23 countries reported 289,690 treatment cycles with: in vitro fertilization (IVF) 120,946, intracytoplasmatisk sperm injection (ICSI) 114,378, frozen embryo replacements (FER) 47,195 and egg donation (ED) 7,171. Intrauterine inseminations are less consistently reported, but in 2001, 15 countries reported 67,124 cycles (IUI-H 52 949 and IUI-D 14 185). Data from 2001 showed that in 12 countries, where all clinics reported the in vitro techniques to the register, 829 treatment cycles were performed per million inhabitants. The availability was highest in the Nordic countries (range 975-1,923 cycles). The proportion of infants born after ART with in vitro techniques ranged from 0.2% in Latvia to 3.9% in Denmark. In general, the impact of the in vitro techniques on the birth rate is highest in the Nordic countries (range 2.2-3.9%). Denmark is the only country with an established National ART reporting system involving all ART treatments both with the in vitro techniques and intrauterine inseminations. In the year 2002, a total of 20,837 treatment cycles were performed. The result was that 6.2% of all infants were born after assisted reproduction.

The role of Gilbert's syndrome and frequent NAT2 slow acetylation polymorphisms in the pharmacokinetics of retigabine

Retigabine (RGB) is an investigational antiepileptic drug, which undergoes extensive UGT1A1, 1A9 and 1A4-mediated N-glucuronidation and N-acetylation. The mono-acetylated metabolite of RGB has some pharmacological activity and is denoted AWD21-360. We investigated whether the pharmacokinetics (PK) of RGB and AWD21-360 are altered in subjects with Gilbert's syndrome (GS) and/or with frequent N-acetyltransferase 2 (NAT2) slow acetylator (SA) polymorphisms. Based on consistent genotyping and phenotyping screening results, 37 Caucasian subjects (21-46 years; 31 men, six women) were assigned to one of the following groups: (1) absence of GS (non-GS)/rapid acetylator (RA) (N=11); (2) GS/RA (N=8); (3) non-GS/SA (N=11); (4) GS/SA (N=7). Subjects received single and multiple (b.i.d.) 200-mg oral RGB doses over 5 days. Blood samples were collected up to 60 h after dosing for plasma PK of RGB and AWD21-360. Group comparisons were performed by ANOVA. Single-dose PK of RGB and AWD21-360 and multiple-dose PK of RGB did not differ significantly between groups. After multiple dose treatment, RA subjects showed a significantly higher total exposure to AWD21-360 of about 32% (95% CI 101.9-172.5) relative to SA subjects (P=0.0362). The UGT1A1 metabolic capacity (i.e. presence or absence of GS), however, did not significantly affect the overall exposure to AWD21-360. The results indicate that the PK of RGB is unaltered in individuals with GS, in subjects with NAT2 SA status, and in carriers of both variants, whereas the total exposure to AWD21-360 is significantly related to the RA or SA status of subjects. Results further suggest that metabolic switching to the mono-acetylated metabolite AWD21-360 may partially compensate for the impaired glucuronidation capacity in GS subjects. RGB treatment showed no significant differences in tolerability and safety between groups.

Impact of follicular-fluid meiosis-activating sterol in an albumin-based formulation on the incidence of human pre-embryos with chromosome abnormalities

OBJECTIVE

To evaluate the effect of adding follicular-fluid meiosis-activating sterol (FF-MAS) in a novel 0.2% recombinant human albumin-based formulation to cumulus-enclosed oocytes on chromosomal status and development of pre-embryos.

DESIGN

Multicenter, prospective, randomized, open (double-blind for vehicle and FF-MAS groups), four parallel groups, controlled trial.

SETTING

Four public IVF clinics in Denmark.

PATIENT(S)

Two hundred eighteen women undergoing IVF donated 483 oocytes.

INTERVENTION(S)

Follicle-stimulating hormone/hCG-primed cumulus-enclosed oocytes randomized to 4 hours of exposure to medium with 1 or 10 micromol/L of FF-MAS dissolved in 0.2% recombinant human albumin, medium with 0.2% recombinant human albumin (vehicle control), or medium alone (control) before insemination.

MAIN OUTCOME MEASURE(S)

Primary endpoint: incidence of human pre-embryos with chromosomal abnormalities. Secondary endpoint: fertilization rate, cleavage rate, and pre-embryo quality assessed after 68 hours of culture.

RESULT(S)

At pre-embryo level, the overall abnormality rates in the control, vehicle control, and 1- and 10-micromol/L FF-MAS groups were 53%, 39%, 42%, 53%, respectively, and at blastomere level 49%, 44%, 44%, and 48%, respectively. After 20 and 26 hours, the fertilization rates were between 67% and 71% in all groups. No differences in the cleavage rates were observed.

CONCLUSION(S)

The concentrations of FF-MAS in a novel 0.2% recombinant human albumin-based formulation of FF-MAS did not increase the risk of chromosomal abnormalities in pre-embryos or blastomeres. No statistically significant differences in fertilization rate, cleavage rate, or number of good quality pre-embryos were found among the four groups.

Neue Richtlinien für die Beurteilung der Bioverfügbarkeit/Bioäquivalenz

Bioavailability and bioequivalence studies are essential in the clinical development of medicinal products and the optimization of pharmaceutical forms. Bioavailability means the rate and extent to which the active substance or active moiety is absorbed from a pharmaceutical form and becomes available at the site of action. In practice, drug concentration-time courses are measured in the systemic circulation, and the area under the curve (AUC) as well as the observed maximum concentration (C(max)) are determined. Products are considered bioequivalent if their bioavailabilities after administration of the same molar doses are similar to such a degree that their effects, with respect to both efficacy and safety, will be essentially the same and thus, there are no relevant differences in terms of AUC and C(max). In 2002 a revised version of the 'Note for Guidance on the Investigation of Bioavailability and Bioequivalence' came into effect (CPMP/EWP/QWP/1401/98). Relevant changes in comparison to the previous version are: request for GLP-compliant bioanalytical measurements; for long half-life drugs a truncated AUC is acceptable; acceptance criteria for bioequivalence assessment and requirements for a waiver of bioequivalence studies were further specified. In this context the Biopharmaceutics Classification System (BCS) seems appropriate to decide whether in special cases of rapidly dissolving solid oral dosage forms a biowaiver may be granted or not. Products not considered critical in this matter are medicinal products for which the formulation does not affect the rate and extent of absorption, i. e. bioavailability, of the active moiety. Highly soluble (and highly permeable) drugs (BCS class I) are such candidates. Comprehensive state-of-the-art guidance on the design, conduct and analysis of bioavailability and bioequivalence studies is given in the current European guideline.

Concentrations of gonadotrophins and steroids in pre-ovulatory follicular fluid and serum in relation to stimulation protocol and outcome of assisted reproduction treatment

In this prospective, randomized study, concentrations of gonadotrophins and steroids in pre-ovulatory follicular fluid (FF) and serum were related to type of stimulation protocol as well as to the outcome of assisted reproduction in 280 women subjected to the long protocol gonadotrophin-releasing hormone (GnRH) agonist pituitary down-regulation and ovarian stimulation with either human menopausal gonadotrophin (HMG) or recombinant FSH. In the women treated with HMG, concentrations of LH, FSH, oestradiol and androstenedione in FF were significantly higher, and those of human chorionic gonadotrophin (HCG) and progesterone significantly lower, than in the women treated with recombinant FSH (rFSH). More women became pregnant and delivered in the HMG than in the rFSH group. These differences, however, were not statistically significant. Concentrations of FSH in serum and of FSH and LH in FF were significantly higher in conception than in non-conception cycles, whereas all other hormone concentrations in FF and serum were similar. The present study demonstrates that the pre-ovulatory follicular fluid hormone profile is significantly influenced by the gonadotrophin preparation used for ovarian stimulation, and suggests that ovarian stimulation with HMG results in an intra-follicular hormone profile more similar to that characterizing conception cycles than stimulation with rFSH. However, as the present data represent means of FF hormone profiles, they do not allow the conclusion of a direct correlation between the intra-follicular concentration of a certain hormone and the ability of the corresponding embryo to implant and establish an ongoing pregnancy.

Placental protein 14 concentrations in circulation related to hormonal parameters and reproductive outcome in women undergoing IVF/ICSI

Serum concentrations of placental protein 14 (PP14), steroids and gonadotrophins were related to the outcome of IVF/intracytoplasmic sperm injection in 195 normogonadotrophic women subjected to the long protocol gonadotrophin-releasing hormone agonist (GnRHa; buserelin) pituitary down-regulation protocol and gonadotrophin stimulation (HMG or rFSH). Pituitary down-regulation was initiated on cycle day 21 and the patients were randomized to either intranasal or s.c. administration of buserelin. After 14 days of down-regulation, the patients were randomized on stimulation day 1 (S1) to ovarian stimulation with 225 IU per day of either human menopausal gonadotrophin (HMG) or recombinant FSH (rFSH) for a fixed period of 7 days. The daily gonadotrophin dose was adjusted on the following day according to ovarian response. Patient's blood was sampled for PP14 and hormone analysis on cycle days 21, S1, S8 and on the day of oocyte retrieval. Mean concentrations of PP14 on day 21 of the cycle were significantly lower in conception than in non-conception cycles, whereas progesterone and oestradiol were similar in conception and non-conception cycles. PP14 concentrations on the first day of stimulation and at oocyte retrieval were significantly higher in conception than in non-conception cycles, whereas concentrations after 8 days of stimulation were similar. Neither mode of GnRHa administration nor type of gonadotrophin significantly influenced PP14 concentrations throughout ovarian stimulation. Circulating PP14 is thus an important physiological signal of the fertility status of the individual in the cycle antecedent to and during ovarian stimulation. Measuring mid-luteal serum PP14 may offer a clinical test helping to decide if infertility treatment should be initiated in the subsequent cycle.

A clinical study comparing PureSperm and SpermFilter for density gradient separation of human spermatozoa in assisted reproduction

OBJECTIVE

To compare a new density gradient medium, SpermFilter, for purifying spermatozoa in assisted reproduction with the more established medium, PureSperm.

DESIGN

Part 1, a multicenter study on 225 semen samples purified using either PureSperm (115 semen samples) or SpermFilter (110 semen samples). Part 2, a retrospective, single center study on a total of 898 assisted reproductive cycles (245 insemination cycles using husband semen, 58 insemination cycles using donor semen and 595 in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) cycles.

SETTING

Part 1, three fertility clinics in Denmark (two university-affiliated fertility clinics and one private clinic). Part 2, one university-affiliated fertility clinic in Denmark.

MAIN OUTCOME PARAMETERS

Part 1, purity of purified spermatozoa (% motile), motility index and recovery of motile spermatozoa. Part 2, malformation and baby take-home rates (insemination cycles), fertilization, cleavage, implantation, malformation and baby take-home rates (IVF/ICSI cycles).

RESULTS

No statistical differences were observed in any of the parameters investigated.

CONCLUSION

SpermFilter is a valid alternative to PureSperm in assisted reproduction technology (ART).

Human menopausal gonadotropin versus recombinant follicle-stimulating hormone in normogonadotropic women down-regulated with a gonadotropin-releasing hormone agonist who were undergoing in vitro fertilization and intracytoplasmic sperm injection: a prospective randomized study

OBJECTIVE

To evaluate clinical and endocrinological effects of intranasal (IN) vs. subcutaneous (SC) GnRH-a for pituitary down-regulation combined with hMG vs. rFSH.

DESIGN

Prospective, randomized study.

SETTING

University hospital, IVF unit.

PATIENT(S)

Three hundred seventy-nine normogonadotropic women eligible for IVF or ICSI.

INTERVENTION(S)

Randomization to intranasal (IN) or SC GnRH-a and to hMG or rFSH.

MAIN OUTCOME MEASURE(S)

Oocytes retrieved, embryos developed, clinical pregnancy, and delivery rates. Serum hormone concentrations on stimulation days 1 (S1) and 8 (S8), and oocyte pick-up (OPU) day.

RESULT(S)

After randomization, four groups were formed: IN/hMG (n = 100), IN/FSH (n = 98), SC/hMG (n = 89), and SC/FSH (n = 92). Mean number of oocytes retrieved and of transferable and transferred embryos were similar in the four groups. Clinical pregnancy rate per started cycle was significantly higher in the IN/HMG group than in the SC/FSH group (P<.05) and was intermediate in the two remaining groups. Se-LH on S8 in the two SC groups was significantly lower than in the two IN groups. Se-E2 on S8 in the SC/FSH group was significantly lower than in the other three groups.

CONCLUSION(S)

The clinical and endocrinological outcome in IVF and ICSI-treated normogonadotropic women is significantly influenced by mode of down-regulation as well as gonadotropin formulation.

Upon prolonged allergen exposure IL-4 and IL-4Ralpha knockout mice produce specific IgE leading to anaphylaxis

BACKGROUND

IL-4 and IL-13 are key regulators in atopic disorders and both signal through the receptor chain IL-4Ralpha. IL-4 and IL-13 are also the only cytokines known to induce class switching to IgE. We sought to compare allergen-specific IgE responses and allergic reactivity of wild-type (wt) mice with IL-4-/- and IL-4Ralpha-/- mice, which lack both IL-4 and IL-13 functions.

METHODS

BALB/c wt, IL-4-/- and IL-4Ralpha-/- mice were immunized with ovalbumin intranasally or intraperitoneally and specific antibody titers were measured by ELISA. Bronchoalveolar lavage fluids and lung tissue were analyzed cytologically and histologically. Allergic reactivity was determined by active cutaneous anaphylaxis and anaphylactic shock.

RESULTS

wt mice immunized intranasally or intraperitoneally showed high titers of specific IgE 3 and 6 weeks after primary sensitization, resulting in cutaneous anaphylaxis and anaphylactic shock upon challenge. Intranasal sensitization resulted in airway eosinophilia and goblet cell metaplasia. In contrast, IL-4-/- and IL-4Ralpha-/- mice showed no specific IgE after 3 weeks, but produced high titers after 6 weeks. At this time cutaneous anaphylaxis and anaphylactic shock could be induced as in wt mice, but lung pathology was absent.

CONCLUSIONS

We conclude that upon long-term allergen exposure, alternative switch mechanisms independent of IL-4 and IL-4Ralpha may induce IgE but not asthma-like lung pathology. This may be relevant for the development of allergic disease, since long-term allergen exposure is a frequent condition during allergic sensitization.

Intrauterine insemination with donor semen. An evaluation of prognostic factors based on a review of 1131 cycles

OBJECTIVE

To identify prognostic factors influencing the outcome of infertility treatment using intrauterine insemination with donor semen (IUI-D).

DESIGN

Retrospective study of all patients undergoing IUI-D between August 1st, 1990 and July 31st, 1998.

SETTING

University-affiliated infertility clinic.

PATIENTS

Three hundred and five couples undergoing 1131 IUI-D treatment cycles.

MAIN OUTCOME MEASURES

Type of hormonal treatment, number of follicles, length of follicular phase, endometrial pattern, female age, infertility diagnosis and semen quality related to clinical pregnancy rate, cumulative birth rate and multiple gestations.

RESULTS

Throughout the nine year period the overall clinical pregnancy rate per cycle was 22.3%, with an increase from 12.9% in 1990 to 34.6% in 1998. The multiple birth rate was 20.6%. The birth rate per couple was 61.1% after a mean of 3.2 treatment cycles. The pregnancy rate was highest in the first treatment cycle and the cumulative birth rate rose only slightly after the sixth treatment cycle. The following parameters were positively and significantly correlated to a successful outcome of IUI-D: i) the first treatment cycle - compared to the following up to six treatment cycles; ii) number of mature follicles - more than one - at the time of insemination, however, with an unacceptable high rate of multiple pregnancies when more than 3 mature follicles were present; iii) time of insemination after the 12th day in the cycle; iv) insemination after ovulation has occurred and; v) female age under 30 years.

CONCLUSIONS

IUI-D is a simple and inexpensive treatment giving acceptable pregnancy rates for up to six treatment cycles if at least 2 mature follicles have developed at the time of insemination, which implies that hormonal ovarian stimulation and induction of ovulation is used, and ovulation has occurred at the time of insemination, which ought to take place after cycle day (cd) 12 with at least two million motile spermatozoa.

Pharmacodynamic effects and plasma pharmacokinetics of single doses of cetrorelix acetate in healthy premenopausal women

OBJECTIVE

To investigate the pharmacodynamic effects and plasma pharmacokinetics of single subcutaneous doses of cetrorelix acetate in healthy premenopausal women.

SETTING

Phase I clinical research unit.

PATIENT(S)

Healthy, premenopausal women aged 19 to 35 years.

INTERVENTION(S)

Single subcutaneous morning doses of cetrorelix acetate (1, 3, or 5 mg peptide base) were investigated in a randomized, single-blind, placebo-controlled, parallel-group design. After a control cycle, 36 women received cetrorelix acetate (12 per dose) and 12 received placebo on the eighth individual cycle day. Transvaginal ultrasound was performed, and blood samples for LH, FSH, E2 were collected during both cycles and for pharmacokinetics up to 168 hours after dosing. The serum hormone levels were determined by electrochemicoluminescence immunoassay and plasma cetrorelix concentrations by radioimmuno assay.

RESULTS

Cetrorelix acetate administration led to a rapid, marked, and reversible suppression of serum LH, E2, and to a lesser extent FSH concentrations. The median intra-individual shifts between treatment and control cycle were -1.0, 4.0, 8.0, and 9.5 days for serum LH maximum and -1.0, 4.5, 7.0, and 10.0 days for ovulation following placebo or 1, 3, and 5 mg cetrorelix acetate, peptide base, respectively. The area under the concentration-time curve (AUC) and peak cetrorelix concentrations in plasma (Cmax) increased proportionally with dose.

CONCLUSIONS

Cetrorelix acetate showed pronounced and reversible LH and E2 suppression and a dose-dependent postponement of LH surge and ovulation after single subcutaneous administrations to healthy premenopausal women. Dose proportionality over the range of 1 mg to 5 mg cetrorelix acetate, peptide base was demonstrated.

Homologous intrauterine insemination. An evaluation of prognostic factors based on a review of 2473 cycles

OBJECTIVE

To identify prognostic factors influencing the outcome of infertility treatment using homologous intrauterine inseminations (IUI-H).

DESIGN

Retrospective study of all patients undergoing IUI-H at the Fertility Clinic, Odense University Hospital from August 1st, 1990 to July 31st, 1998.

SETTING

University-affiliated infertility clinic.

PATIENTS

Eight hundred and ninety-three couples undergoing 2473 IUI-H treatment cycles.

MAIN OUTCOME MEASURES

Infertility diagnosis, female age, number of follicles, type of hormonal treatment, length of follicular phase, endometrial pattern, and semen quality related to clinical pregnancy rate, cumulative birth rate and multiple gestations.

RESULTS

Throughout the nine year period the overall clinical pregnancy rate per IUI-H cycle was 11.9% with a significant increase from 8.7% in 1990 to 14.8% in 1998. The multiple birth rate was 18.1%. The birth rate per couple was 27.2% after a mean of 2.8 treatment cycles. The pregnancy rate was highest in the first treatment cycle and the cumulative birth rate rose only slightly after the fourth treatment cycle. Of the main outcome measures the following were positively and significantly related to a successful outcome of IUI: i) The first treatment cycle - compared to the following up to six treatment cycles; ii) number of mature follicles up to five - at the time of insemination, however, with an unacceptable high rate of multiple pregnancies with more than 4 mature follicles; iii) use of CC/hMG-FSH as compared to CC only for ovarian stimulation; iv) number of motile sperms inseminated exceeding 5 million; v) time of insemination between the 13th and the 16th day in the cycle and vi) anovulatory or idiopathic infertility.

CONCLUSIONS

IUI-H is a simple and inexpensive treatment giving acceptable pregnancy rates for up to four treatment cycles providing that at least 3 to 4 mature follicles have developed at the time of insemination, which implies that hormonal ovarian stimulation and induction of ovulation is used, that insemination occurs between cycle day 13 and 16 and that at least 5 million motile sperms are available for insemination. Our results indicate that in the presence of tubal pathology or less than 5 million motile sperms, the couples should be referred directly to IVF-treatment.

Pharmacokinetic and pharmacodynamic modeling of cetrorelix, an LH-RH antagonist, after subcutaneous administration in healthy premenopausal women

PURPOSE

The purpose of this study was the development of pharmacokinetic and pharmacodynamic models for the luteinizing hormone (LH) suppression and subsequent shift in LH surge and follicle-stimulating hormone by cetrorelix in women.

BACKGROUND

Cetrorelix is a potent luteinizing hormone-releasing hormone (LH-RH) antagonist and is used for the prevention of the premature ovulation indicated by an LH surge in in vitro fertilization. The pharmacokinetic and pharmacodynamic relationship for the suppression and the shift in the LH surge has not yet been established.

METHODS

In a placebo-controlled study, single subcutaneous doses of 1, 3, and 5 mg of cetrorelix were given to 36 subjects on day 8 of the natural menstrual cycle. Cetrorelix, LH, follicle-stimulating hormone, estradiol, and progesterone were determined.

RESULTS

Cetrorelix pharmacokinetics were described by a 2-compartment model with a terminal half-life of 56.9 +/- 27.1 hours. Mean shift in LH surge was by 4.1, 7.5, and 9.3 days with the 1-, 3-, and 5-mg doses, respectively. An indirect response sigmoid Emax model was developed for the suppression of LH and the shift in the LH surge. The inhibitory concentration of 50% (for LH suppression) and median effective concentration (for surge shift) estimates were 3.6 ng/mL and 1.6 ng/mL, respectively. The suppression of follicle-stimulating hormone was described by a similar Emax model, with an inhibitory concentration of 50% of 7.25 ng/mL.

CONCLUSIONS

A pharmacokinetic and pharmacodynamic model was developed for the transient initial suppression of LH and the subsequent shift in the LH surge after 3 single subcutaneous doses of cetrorelix without ovarian stimulation. A separate model was developed for the suppression of follicle-stimulating hormone by cetrorelix. The shift in the LH surge could be adequately described by the model.

The influence of infections on the development and severity of allergic disorders

The frequency and severity of atopic disorders are steadily increasing, particularly in developing countries. The reason for this observation is not clear. Recent studies indicate that infections with viruses and especially with bacteria early in life may help to inhibit allergic Th2 responses by skewing the immune system towards Th1 responses. However, infections can also lead to the exacerbation of atopic disorders.

Molecular diagnosis of a familial nonhemolytic hyperbilirubinemia (Gilbert's syndrome) in healthy subjects

Recent research has shown that congenital nonhemolytic low grade hyperbilirubinemias in patients with Gilbert's syndrome (GS) are linked to mutations in the TATA box upstream of the uridine 5'-diphosphoglucose glucuronosyltransferase (UGT1A1) gene leading to an impaired bilirubin glucuronidation. In routine clinical practice GS patients can, however, only be suspected by exclusion of other causes of hyperbilirubinemia or substantial liver diseases. We developed a new, sensitive, convenient, and economic polymerase chain reaction (PCR) method for the rapid and reliable identification of gene polymorphisms in the TATA box of the UGT1A1 gene using fluorescence resonance energy transfer (FRET). With this procedure the genotype frequency in a cohort of 266 unrelated individuals from Southern Germany was investigated and the allelic distribution for individual genotypes was 43:45:12 for the (TA)(6)TAA:(TA)(6)TAA/(TA)(7)TAA:(TA)(7)TAA alleles, respectively. The homozygous (TA)(7)TAA genotype was strongly associated with suspected Gilbert's patients and its prevalence in our cohort of 266 Southern German individuals was 12.4%. In this cohort total mean serum bilirubin levels ranged from 5 micromol/L (wild-type 6/6 allele) to 57 micromol/L serum total bilirubin (mutant 7/7 homozygous allele). Median (interquartile range) serum total bilirubin levels were 12 (6) and 21 (13) for the homozygous wild-type and mutant allele, respectively. Our assay enables individual guidance for dose adjustment in suspected GS patients undergoing long-term drug therapies, especially if glucuronidation via UGT1A1 is a major metabolic pathway.

Selective suppression of inhibitory synaptic transmission by nocistatin in the rat spinal cord dorsal horn

Nociceptin/orphanin FQ (N/OFQ) and nocistatin (NST) are two recently identified neuropeptides with opposing effects on several CNS functions, including spinal nociception. The cellular mechanisms that underlie this antagonism are not known. Here, we have investigated the effects of both peptides on synaptic transmission mediated by the three fast neurotransmitters l-glutamate, glycine, and GABA in the superficial layers of the rat spinal cord horn, which constitute the first important site of integration of nociceptive information in the pain pathway. NST selectively reduced transmitter release from inhibitory interneurons via a presynaptic Bordetella pertussis toxin-sensitive mechanism but left excitatory glutamatergic transmission unaffected. In contrast, N/OFQ only inhibited excitatory transmission. In the rat formalin test, an animal model of tonic pain in which N/OFQ exerts antinociceptive activity, NST induced profound hyperalgesia after intrathecal application. Similar to glycine and GABA(A) receptor antagonists, NST had no significant effects in the rat tail-flick test, a model of acute thermal pain. Our results provide a cellular basis for the antagonism of N/OFQ and NST and suggest the existence of a so far unidentified membrane receptor for NST. In addition, they support a role of NST as an endogenous inhibitor of glycinergic and GABAergic neurotransmission in the sensory part of the spinal cord and as a mediator of spinal hyperalgesia.

Pituitary and gonadal endocrine effects and pharmacokinetics of the novel luteinizing hormone-releasing hormone antagonist teverelix in healthy men--a first-dose-in-humans study

BACKGROUND. Teverelix is a novel synthetic peptidic luteinizing hormone-releasing hormone (LHRH) antagonist.

METHODS

Single subcutaneous morning doses of teverelix acetate (either 0.5, 1, 2, 3, or 5 mg base) were investigated in a randomized, single-blind, placebo-controlled, dose-escalating parallel-group design in healthy men. Six subjects received teverelix, and two subjects received placebo per dose level. Blood samples for lutropin, luteinizing hormone (LH), and follitropin, follicle-stimulating hormone (FSH), and testosterone, as well as for pharmacokinetics, were withdrawn up to 120 hours after dosing. Serum hormone levels were determined by electrochemicoluminescence immunoassays, and plasma teverelix concentrations were determined by radioimmunoassay.

RESULTS

Teverelix led to a rapid, marked suppression of LH, testosterone and, to a lesser extent, FSH. Median maximum suppressions compared with predose levels were -93% for LH and -54% for FSH after teverelix 5 mg, and -93% for testosterone after teverelix 3 mg, respectively. After 5 mg teverelix, testosterone suppression <1 ng/mL started a median of 12 hours after dosing and lasted for a median of 33 hours. The duration of testosterone suppression increased with dose. Geometric means of peak teverilix plasma concentrations were 4.5 ng/mL (0.5 mg teverelix) to 49.0 ng/mL (5 mg teverelix) and tmax occurred between 1 and 4 hours after dosing. Geometric means of the area under the teverelix plasma concentration-time course from zero to time of the last quantifiable plasma concentration [AUC(O-tlast)] were 54.9 ng x h/mL (0.5 mg teverelix) to 881.8 ng x h/mL (5 mg teverelix). Median values for apparent terminal half-lives ranged from 24 to 75 hours. The most frequently reported adverse events were short-lasting mild injection-site reactions.

CONCLUSIONS

Teverelix showed pronounced LH and testosterone suppressive effects after single subcutaneous doses in healthy men. Duration of hormone suppression increased with dose. Teverelix was well tolerated. This profile indicates potential for further clinical use.