Development of an Intrauterine Device Releasing Both Indomethacin and Levonorgestrel During the First Months of Use: Pharmacokinetic Characterization in Healthy Women.

BACKGROUND: Post-placement menstrual bleeding pattern changes with intrauterine contraceptives (IUCs), including levonorgestrel-releasing intrauterine systems (LNG-IUS), can be a reason for avoidance or early discontinuation. Prostaglandins play an important role in menstrual bleeding and pain. The key drivers of prostaglandin synthesis are cyclooxygenase (COX) enzymes, which are inhibited by non-steroidal anti-inflammatory drugs. In this study, we report the findings from pharmacokinetic (PK) analyses undertaken with an LNG-IUS (LNG-IUS 8) modified with an additional reservoir containing indomethacin (IND). METHODS: The IND/LNG-IUS 8 is a proof-of-concept device studied in a phase II proof-of-concept/dose-finding study. IND/LNG-IUS 8 contains the same LNG content as the unmodified LNG-IUS 8 (13.5 mg) but was prepared with three different IND doses (low, 6.5 mg; middle, 12.5 mg; and high, 15.4 mg), resulting in different daily release rates. Overall, 174 healthy, premenopausal women were randomized to one of the four treatment arms (low-, middle-, high-dose IND/LNG-IUS 8 or LNG-IUS 8). Initial and residual IND and LNG content were collected and the amount of IND and LNG released in vivo over the period of use was calculated. A subset of 62 participants underwent dense blood sampling for PK analysis. Concentrations of IND and LNG in plasma were determined by validated liquid chromatography-tandem mass spectrometry methods and plotted over time. Descriptive statistics were calculated for plasma drug concentrations and PK parameters. RESULTS: High-dose IND/LNG-IUS 8 initially released much higher levels of IND than expected based on in vitro release data, followed by a steep decline, with the reservoir emptied by 4.5 months. Middle- and low-dose IND/LNG-IUS 8 demonstrated steady sustained release of IND over time, emptying after 7.4 and 8.4 months, respectively. Peak plasma concentrations of IND for low- and middle-dose IND/LNG-IUS 8 remained below the 20% maximal inhibitory concentration (IC20) values for COX enzymes. The average daily IND release rate in vivo was 49 µg/day for low-dose and 112 µg/day for middle-dose IND/LNG-IUS 8. The IND release rate profile and IND plasma concentrations in vitro both decreased steadily over time with low- and middle-dose IND/LNG-IUS 8. The LNG release rate profile was comparable for all IND/LNG-IUS 8 dose groups and LNG-IUS 8. CONCLUSION: This PK study demonstrates that two different drugs can be released at different rates from an IUS designed with two drug reservoirs. Inclusion of IND does not impact the LNG PK profile. Low- and middle-dose IND/LNG-IUS 8 were associated with a systemic IND exposure that should preclude the occurrence of adverse events typically observed after oral IND dosing. STUDY REGISTRATION: ClinicalTrials.gov identifier number: NCT03562624.

The effect of a combined indomethacin and levonorgestrel-releasing intrauterine system on short-term postplacement bleeding profile: a randomized proof-of-concept trial.

BACKGROUND: Long-acting reversible contraceptives, including hormonal levonorgestrel-releasing intrauterine systems, are the most effective methods of reversible contraception. However, unfavorable bleeding, particularly during the first months of use, is one of the most important reasons for discontinuation or avoidance. Minimizing this as early as possible would be highly beneficial. Nonsteroidal anti-inflammatory drugs inhibiting prostaglandin synthesis are known to reduce bleeding and pain at time of menses. A levonorgestrel-releasing intrauterine system has been developed with an additional reservoir containing indomethacin, designed to be released during the initial postplacement period. OBJECTIVE: This proof-of-concept study aimed to establish whether the addition of indomethacin to the currently available levonorgestrel-releasing intrauterine system (average in vivo levonorgestrel release rate of 8 µg/24 h during the first year of use) reduces the number of bleeding and spotting days during the first 90 days of use compared with the unmodified system. The dose-finding analysis included 3 doses of indomethacin-low (6.5 mg), middle (12.5 mg), and high (15.4 mg)-to determine the ideal dose of indomethacin to reduce bleeding and spotting days with minimal side-effects. STUDY DESIGN: This was a multicenter, single-blinded, randomized, controlled phase II trial conducted between June 2018 and June 2019 at 6 centers in Europe. Three indomethacin dose-ranging treatment groups (low-, middle-, and high-dose indomethacin/levonorgestrel-releasing intrauterine system) were compared with the unmodified levonorgestrel-releasing intrauterine system group, with participants randomized in a 1:1:1:1 ratio. The primary outcome was the number of uterine bleeding and spotting days over a 90-day reference (treatment) period. Secondary outcomes were the number of women showing endometrial histology expected for intrauterine levonorgestrel application and the frequency of treatment-emergent adverse events. Point estimates and 2-sided 90% credible intervals were calculated for mean and median differences between treatment groups and the levonorgestrel-releasing intrauterine system without indomethacin. Point and interval estimates were determined using a Bayesian analysis. RESULTS: A total of 174 healthy, premenopausal women, aged 18 to 45 years, were randomized, with 160 women eligible for the per-protocol analysis set. Fewer bleeding and spotting days were observed in the 90-day reference period for the 3 indomethacin/levonorgestrel-releasing intrauterine system dose groups than for the levonorgestrel-releasing intrauterine system without indomethacin group. The largest reduction in bleeding and spotting days was achieved with low-dose indomethacin/levonorgestrel-releasing intrauterine system, which demonstrated a point estimate difference of -32% (90% credible interval, -45% to -19%) compared with levonorgestrel-releasing intrauterine system without indomethacin. Differences for high- and middle-dose indomethacin/levonorgestrel-releasing intrauterine system groups relative to levonorgestrel-releasing intrauterine system without indomethacin were -19% and -16%, respectively. Overall, 97 women (58.1%) experienced a treatment-emergent adverse event considered related to the study drug, with similar incidence across all treatment groups including the unmodified levonorgestrel-releasing intrauterine system. These were all mild or moderate in intensity, with 6 leading to discontinuation. Endometrial biopsy findings were consistent with effects expected for the levonorgestrel-releasing intrauterine system. CONCLUSION: All 3 doses of indomethacin substantially reduced the number of bleeding and spotting days in the first 90 days after placement of the levonorgestrel-releasing intrauterine system, thus providing proof of concept. Adding indomethacin to the levonorgestrel-releasing intrauterine system can reduce the number of bleeding and spotting days in the initial 90 days postplacement, without affecting the safety profile, and potentially improving patient acceptability and satisfaction.

Discovery of BAY-298 and BAY-899: Tetrahydro-1,6-naphthyridine-Based, Potent, and Selective Antagonists of the Luteinizing Hormone Receptor Which Reduce Sex Hormone Levels in Vivo.

The human luteinizing hormone receptor (hLH-R) is a member of the glycoprotein hormone family of G-protein-coupled receptors (GPCRs), activated by luteinizing hormone (hLH) and essentially involved in the regulation of sex hormone production. Thus, hLH-R represents a valid target for the treatment of sex hormone-dependent cancers and diseases (polycystic ovary syndrome, uterine fibroids, endometriosis) as well as contraception. Screening of the Bayer compound library led to the discovery of tetrahydrothienopyridine derivatives as novel, small-molecule (SMOL) hLH-R inhibitors and to the development of BAY-298, the first nanomolar hLH-R antagonist reducing sex hormone levels in vivo. Further optimization of physicochemical, pharmacokinetic, and safety parameters led to the identification of BAY-899 with an improved in vitro profile and proven efficacy in vivo. BAY-298 and BAY-899 serve as valuable tool compounds to study hLH-R signaling in vitro and to interfere with the production of sex hormones in vivo.

The water permeability channels aquaporins 1-4 are differentially expressed in granulosa and theca cells of the preovulatory follicle during precise stages of human ovulation.

CONTEXT: Changes in vascular permeability and expansion of the fluid-filled antrum are major events in the LH-induced ovulatory process. OBJECTIVES: Our objective was to investigate the presence and expression levels of aquaporins (AQPs) in the granulosa and theca cell compartments of the follicle during defined phases of human ovulation. DESIGN AND SETTING: We conducted a prospective experimental study at the Department of Obstetrics and Gynaecology at a university hospital. PARTICIPANTS: Twenty-eight women underwent laparoscopic sterilization and at the same time follicle retrieval at four periovulatory phases. MAIN OUTCOME MEASURES: mRNA levels of AQP1-4 were measured in separated granulosa and theca cells from preovulatory phase, early ovulatory (EO) phase, late ovulatory phase, and postovulatory phase. Immunohistochemistry was done for AQP1-4 in intact human follicles. RESULTS: All four AQPs were expressed in both the theca and granulosa cells during ovulation. In granulosa cells, AQP1 levels increased in the late ovulatory and postovulatory phases. Expression of AQP2-3 followed a similar pattern with a marked increase in the EO phase, whereas AQP4 levels decreased from preovulatory to the EO phase. The presence of AQP1-4 in the human follicle was verified by immunohistochemistry. CONCLUSIONS: The results show for the first time the presence of AQP1-4 in human follicles during ovulation. The marked early rise in expression of AQP2 and AQP3 suggests a role during the process leading to follicular rupture, and the late rise of AQP1 suggests a role in corpus luteum formation.

Dynamics of the transcriptome in the primate ovulatory follicle.

Experiments were designed to evaluate changes in the transcriptome (mRNA levels) in the ovulatory, luteinizing follicle of rhesus monkeys, using a controlled ovulation model that permits analysis of the naturally selected, dominant follicle at specific intervals (0, 12, 24 and 36 h) after exposure to an ovulatory (exogenous hCG) stimulus during the menstrual cycle. Total RNA was prepared from individual follicles (n= 4-8/timepoint), with an aliquot used for microarray analysis (Affymetrix Rhesus Macaque Genome Array) and the remainder applied to quantitative real-time PCR (q-PCR) assays. The microarray data from individual samples distinctly clustered according to timepoints, and ovulated follicles displayed markedly different expression patterns from unruptured follicles at 36 h. Between timepoint comparisons revealed profound changes in mRNA expression profiles. The dynamic pattern of mRNA expression for steroidogenic enzymes (CYP17A, CYP19A, HSD3B2, HSD11B1 and HSD11B2), steroidogenic acute regulatory protein (StAR) and gonadotrophin receptors [LH/choriogonadotrophin receptor (LHCGR), FSH receptor (FSHR)] as determined by microarray analysis correlated precisely with those from blinded q-PCR assays. Patterns of mRNA expression for epidermal-growth-factor-like factors (amphiregulin, epiregulin) and processes [hyaluronan synthase 2 (HAS2), tumor necrosis factor alpha-induced protein 6 (TNFAIP6)] implicated in cumulus-oocyte maturation/expansion were also comparable between assays. Thus, several mRNAs displayed the expected expression pattern for purported theca (e.g. CYP17A), granulosa (CYP19A, FSHR), cumulus (HAS2, TNFAIP6) cell and surface epithelium (HSD11B)-related genes in the rodent/primate pre-ovulatory follicle. This database will be of great value in analyzing molecular and cellular pathways associated with periovulatory events in the primate follicle (e.g. follicle rupture, luteinization, inflammatory response and angiogenesis), and for identifying novel gene products controlling mammalian fertility.

Isotopomer spectral analysis of intermediates of cholesterol synthesis in patients with cerebrotendinous xanthomatosis.

Four patients with cerebrotendinous xanthomatosis (CTX) and 2 healthy controls received a constant proximal intraduodenal infusion of 1- 13 C-acetate as a stable-isotope-labeled marker of sterol synthesis. One patient was treated with pravastatin (20 mg twice daily) and another patient with chenodeoxycholic acid (250 mg tid). Every hour, venous blood and duodenal samples were obtained. Stable-isotope enrichment of neutral and polar sterols in serum and bile was assessed by gas chromatography/mass spectrometry. Isotopomer spectral analysis was performed on cholesterol, lathosterol, Delta-8-cholesterol, methylsterol, and lanosterol. Stable-isotope labeling of cholestanol, bile acids, and bile alcohols was analyzed by assessing the change over time of the ratio of M + 3 to M + 0. Eleven hours after marker infusion, we found up to 50% newly synthesized lathosterol in serum and up to 80% in bile, with similar results for other cholesterol precursors. In cholesterol, stable-isotope labeling could be demonstrated in all study subjects with a more prominent labeling in bile than in serum. No stable-isotope labeling was detected in cholestanol. Only minor stable-isotope incorporation was detectable in polar sterols in some subjects. Therapy with pravastatin did not have any effect on fractional or absolute synthesis rates or on the concentrations of cholestanol or cholesterol precursors compared to untreated patients with CTX. In contrast, therapy with chenodeoxycholic acid markedly lowered the concentrations of cholestanol and cholesterol precursors, led to a disappearance of bile alcohols, and reduced absolute synthesis rates of lathosterol. Isotopomer spectral analysis proved to be a powerful method to assess the endogenous synthesis of cholesterol precursors in patients with CTX. Higher fractional synthesis in bile than in serum may be due to the size of the pools in bile vs serum. Cholestanol exhibits no marker uptake and is therefore probably synthesized from preformed cholesterol. Biliary cholesterol secretion in patients with CTX is decreased compared to healthy controls.

High doses of simvastatin, pravastatin, and cholesterol reduce brain cholesterol synthesis in guinea pigs.

Recent epidemiological studies suggest that inhibitors of 3-hydroxy-3-methyl-glutaryl CoA reductase, so-called statins, are effective in lowering the prevalence of Alzheimer's disease. Whether the effect of statins is due to a local inhibition of cholesterol synthesis in the brain or whether it is mediated by the reduced levels of cholesterol in the circulation is not known. In the present work, we tested the possibility that high doses of lipophilic and hydrophilic statins, simvastatin and pravastatin, respectively, or a diet high in cholesterol could affect cholesterol homeostasis in the brain of guinea pigs. The total brain cholesterol levels were not affected by high-dose simvastatin or pravastatin treatment. Significantly lower levels of the cholesterol precursor lathosterol and its ratio to cholesterol were found in the brains of simvastatin and pravastatin-treated animals. 24S-Hydroxycholesterol, the transportable form of cholesterol across the blood-brain barrier, was significantly lower in the brain of pravastatin-treated animals. Excessive cholesterol feeding resulted in higher serum cholesterol levels but did not affect total brain cholesterol level. However, de novo cholesterol synthesis in the brain seemed to be down-regulated, as indicated by lower absolute levels and cholesterol-related ratios of lathosterol compared with controls. The passage of deuterium-labeled cholesterol across the blood-brain barrier in one animal was found to be approximately 1%. Our results suggest that brain cholesterol synthesis in guinea pigs can be slightly, but significantly, influenced by high doses of lipophilic and hydrophilic statins as well as by high dietary cholesterol intake, while total brain cholesterol content and thus, cholesterol homeostasis is maintained.

Efficiency of intestinal cholesterol absorption in humans is not related to apoE phenotype.

The present study investigated the role of apolipoprotein E (apoE) phenotype on intestinal cholesterol absorption and cholesterol synthesis. Studies were carried out in eight subjects homozygous for the apoE4 and 12 subjects homozygous for the E2 allele (six normocholesterolemic volunteers and six patients with type III hyperlipoproteinemia). Cholesterol absorption did not differ between the three groups of subjects and averaged 38 +/- 2% (mean +/- SEM) in normolipemic E2/2, 37 +/- 4% in type III hyperlipemic E2/2, and 41 +/- 3% in E4/4 subjects, respectively. Dietary intake of fat and cholesterol had no influence on cholesterol absorption efficiency. A positive correlation between efficiency of cholesterol absorption and the ratio of campesterol to cholesterol in plasma, an indirect marker for cholesterol absorption, was observed after combining the results of the three groups (r = 0.504; P < 0.02). Bile acid and total cholesterol synthesis were also not affected by the different apoE alleles, but the well-known relationship between body weight and cholesterol synthesis was noticed (r = 0.574; P < 0.01). Thus, the present study provides evidence that the efficiency of intestinal absorption and synthesis of cholesterol in humans are not related to the apoE phenotype.

Serum plant sterols and biliary cholesterol secretion in humans: studies with ursodeoxycholic acid.

Ratios of cholestanol, campesterol, and sitosterol to cholesterol in serum are known to reflect cholesterol absorption efficiency. Here, a possible link between these ratios and biliary secretion rates of cholesterol was investigated. Biliary lipid secretion rates and serum sterols were determined in 13 patients with gallstones. Seven were treated with ursodeoxycholic acid (UDCA) (1,000 mg/d). Serum cholesterol and non-cholesterol sterols were also measured in a cross over study in 20 healthy volunteers, who received either placebo or UDCA (750 mg/d). Biliary cholesterol secretion was significantly lower, whereas the non-cholesterol sterols and their ratio to cholesterol were higher in patients with gallstones treated with UDCA. A highly significant negative linear correlation between the ratios of non-cholesterol sterols to cholesterol and biliary cholesterol secretion was observed. In volunteers, administration of UDCA for 4 weeks was followed by a significant increase in non-cholesterol sterols and their ratios. Even 4 weeks after discontinuing UDCA administration, campesterol and sitosterol were still significantly higher than pretreatment levels, which was also true for the campesterol-cholesterol ratio after 8 weeks. The results suggest that the ratios of cholestanol, campesterol, and sitosterol to cholesterol can be used as indicators of changes in biliary cholesterol secretion rates.

Influence of simvastatin, pravastatin, and BM 15.766 on neutral sterols in liver and testis of guinea pigs.

There is mounting evidence that specific sterol precursors of cholesterol are associated with reproductive functions. Testicular meiosis-activating sterol (T-MAS) and follicular fluid meiosis-activating-sterol (FF-MAS) are 2 cholesterol precursors found in reproductive organs of mammals, which are able to overcome meiotic arrest in vitro. This study investigates the influence of simvastatin and pravastatin, 2 inhibitors of 3-hydroxy-3-methyl-glutaryl coenzyme A (HMG-CoA) reductase, and BM 15.766, an inhibitor of 7-dehydrocholesterol reductase, on concentrations of neutral sterols in liver and testis of guinea pigs. Concentrations of T-MAS, lathosterol, and desmosterol were markedly higher in testis compared with liver. Simvastatin (150 mg/d) and pravastatin (150 mg/d and 350 mg/d) markedly reduced cholesterol precursors in liver. In contrast, T-MAS and desmosterol in testis remained unchanged, albeit other cholesterol precursors were reduced. BM 15.766 led to the accumulation of 7- and 8-dehydrocholesterol, both in liver and testis. However, concentrations of T-MAS in testis were not changed by BM 15.766. We conclude that treatment of guinea pigs with simvastatin, pravastatin, or BM 15.766, which simulates the biochemical defect of the Smith-Lemli-Opitz (SLO) syndrome, does not affect T-MAS concentrations in testis.