GSK4716 enhances 5-HT1AR expression by glucocorticoid receptor signaling in hippocampal HT22 cells.

OBJECTIVES: The serotonin (5-hydroxytryptamine, 5-HT) receptor 1A (5-HT1AR) is closely associated with serotonergic neurotransmission in the brain, being the most prevalent and widely distributed receptor of its kind. The purpose of this study is to investigate the regulation mechanism of 5-HT1AR by GSK4716. METHODS: To investigate the mechanism of GSK4716-mediated 5-HT1AR regulation, we used hippocampus-derived HT22 cells expressing 5-HT1AR. The expression level of 5-HT1AR and associated proteins, were detected by reporter gene assay and western blotting. RESULTS: GSK4716, an estrogen-related receptor gamma agonist increased 5-HT1AR expression by interacting with the GR, a repressor of 5-HT1AR transcription. Dexamethasone, a GR agonist, decreased the GSK4716-induced increase in 5-HT1AR, which was associated with an alteration in nuclear GR. Furthermore, GR antagonist RU486 reversed the effects induced by dexamethasone, including the elevation of nuclear GR levels and the reduction of 5-HT1AR transcription and expression. CONCLUSION: The results could provide insight into the potential applications of small molecules, such as GSK4716, in the regulation of 5-HT1AR expression, which plays a role in serotonergic neurotransmission.

Significant Palliative Benefits Following Therapy With Mifepristone for Advanced Treatment Resistant Small Cell Lung Cancer.

BACKGROUND/AIM: Progesterone receptor antagonists have been found to provide significant extension of life and considerable palliative benefits in a large variety of very advanced cancers. Most of these treated cancers lack the classical nuclear progesterone receptor (nPR). The hypothesized targets are membrane (m) PRs to inhibit progesterone induced blocking factor (PIBF). To date, there have been no case reports documenting the efficacy of PR antagonists for small cell lung cancer (SCLC) confirmed by pathological analysis. The case reported here demonstrates the efficacy of the single oral agent mifepristone in treating resistant SCLC. CASE REPORT: A 58-year-old man, presenting with a persistent cough, dyspnea on exertion, and marked weakness, was diagnosed with stage IV non-SCLC (NSCLC) that tested positive for the EGFR mutation. He was treated with the single agent osimertinib. When symptoms returned eight months later, along with radiographic evidence of marked cancer progression, a lung biopsy showed SCLC. He failed to respond to pembrolizumab and subsequently to atezolizumab. He was then treated with the single agent mifepristone 200 mg per day orally. He showed marked clinical improvement associated with marked radiographic improvement. Though clinically doing very well, after one year, his dominant lesion increased in size. His oncologist elected to stop mifepristone and treat with camrelizumab with anlototinib. His clinical condition deteriorated on these drugs, and he died five months later. CONCLUSION: SCLC can be added to the long list of very advanced cancers that are treatment resistant to standard therapy, but respond well to PR antagonists.

A case report of vaginal delivery in the second trimester of severe uterine prolapse complicated with cervical incarceration.

BACKGROUND: Uterine prolapse is a rare complication of pregnancy, and there is still no consensus on the choice of delivery method. METHODS: The patient's reproductive history included an abortion and eutocic delivery of a girl weighing 3200 g; the current pregnancy was the third pregnancy. Her cervical region was outside the vaginal opening and was red in color, with evident enlargement (6 × 4 cm) and a broken surface. The cervical area also showed white discharge. According to her Transvaginal ultrasonography revealed a fetus in the uterine cavity at approximately 19 weeks of gestation. Gynecological examination revealed prolapse of both the anterior and posterior vaginal walls. Evaluation of the pelvic organ prolapse-Q scores showed that the patient had uterine prolapse at stage IV. RESULTS: Vaginal delivery was performed smoothly after oral administration mifepristone and misoprostol tablets for a few days, obtaining a dead female fetus in cephalic, 25 cm in length. The cervix of the pregnant woman did not prolapse during the delivery. CONCLUSION: For pregnancy with uterine prolapse and cervical incarceration, transvaginal delivery is a potential treatment option. Maintenance of cervical retraction and oral mifepristone administration with misoprostol tablets is crucial during this delivery. This treatment can minimize the risk of cervical lacerations and uterine rupture, helping surgeons to complete the operation successfully.

Selective Modulation of the Human Glucocorticoid Receptor Compromises GR Chromatin Occupancy and Recruitment of p300/CBP and the Mediator Complex.

Exogenous glucocorticoids are frequently used to treat inflammatory disorders and as adjuncts for the treatment of solid cancers. However, their use is associated with severe side effects and therapy resistance. Novel glucocorticoid receptor (GR) ligands with a patient-validated reduced side effect profile have not yet reached the clinic. GR is a member of the nuclear receptor family of transcription factors and heavily relies on interactions with coregulator proteins for its transcriptional activity. To elucidate the role of the GR interactome in the differential transcriptional activity of GR following treatment with the selective GR agonist and modulator dagrocorat compared to classic (ant)agonists, we generated comprehensive interactome maps by high-confidence proximity proteomics in lung epithelial carcinoma cells. We found that dagrocorat and the antagonist RU486 both reduced GR interaction with CREB-binding protein/p300 and the mediator complex compared to the full GR agonist dexamethasone. Chromatin immunoprecipitation assays revealed that these changes in GR interactome were accompanied by reduced GR chromatin occupancy with dagrocorat and RU486. Our data offer new insights into the role of differential coregulator recruitment in shaping ligand-specific GR-mediated transcriptional responses.

Mifepristone decreases nicotine intake in dependent and non-dependent adult rats.

BACKGROUND: Addiction to tobacco and nicotine products has adverse health effects and afflicts more than a billion people worldwide. Therefore, there is an urgent need for new treatments to reduce tobacco and nicotine use. Glucocorticoid receptor blockade shows promise as a novel treatment for drug abuse and stress-related disorders. AIM: These studies aim to investigate whether glucocorticoid receptor blockade with mifepristone diminishes the reinforcing properties of nicotine in rats with intermittent or daily long access to nicotine. METHODS: The rats self-administered 0.06 mg/kg/inf of nicotine for 6 h per day, with either intermittent or daily access for 4 weeks before treatment with mifepristone. Daily nicotine self-administration models regular smoking, while intermittent nicotine self-administration models occasional smoking. To determine whether the rats were dependent, they were treated with the nicotinic acetylcholine receptor antagonist mecamylamine, and somatic signs were recorded. RESULTS: The rats with intermittent access to nicotine had a higher level of nicotine intake per session than those with daily access but only the rats with daily access to nicotine showed signs of physical dependence. Furthermore, mecamylamine increased nicotine intake during the first hour of access in rats with daily access but not in those with intermittent access. Mifepristone decreased total nicotine intake in rats with intermittent and daily access to nicotine. Moreover, mifepristone decreased the distance traveled and rearing in the open field test and operant responding for food pellets. CONCLUSION: These findings indicate that mifepristone decreases nicotine intake but this effect may be partially attributed to the sedative effects of mifepristone.

Adjuvant misoprostol or mifepristone for cervical preparation with osmotic dilators before dilation and evacuation.

OBJECTIVES: This study aimed to compare effectiveness and safety of cervical preparation with osmotic dilators plus same-day misoprostol or overnight mifepristone prior to dilation and evacuation (D&E). STUDY DESIGN: We conducted a retrospective cohort analysis of 664 patients initiating abortion between 18 and 22 weeks at an ambulatory health center. We abstracted medical record data from two consecutive 12-month periods in 2017 to 2019. All patients received overnight dilators plus: 600 mcg buccal misoprostol 90 minutes before D&E (period 1); 200 mg oral mifepristone at time of dilators (period 2). Our primary outcome was procedure time. We report frequency of patients experiencing any acute complication, defined as unplanned procedure (i.e., reaspiration, cervical laceration repair, uterine balloon tamponade) or hospital transfer and bleeding complications. RESULTS: We observed higher mean procedure time in the mifepristone group (9.7 ± 5.3 minutes vs 7.9 ± 4.4, p = 0.004). After adjusting for race, ethnicity, insurance, body mass index, parity, prior cesarean, prior uterine surgery, gestational age, provider, trainee participation, and long-acting reversible contraception initiation, the difference remained statistically significant (relative change 1.09, 95% CI 1.01, 1.17) but failed to reach our threshold for clinical significance. The use of additional misoprostol was more common in the mifepristone group, but the use of an additional set of dilators was not different between groups. Acute complications occurred at a frequency of 4.1% in misoprostol group and 4.3% in mifepristone group (p = 0.90). CONCLUSIONS: We found procedure time to be longer with adjunctive mifepristone compared to misoprostol; however, this difference is unlikely to be clinically meaningful. Furthermore, the frequency of acute complications was similar between groups. IMPLICATIONS: Overnight mifepristone at the time of cervical dilator placement is a safe and effective alternative to adjuvant same-day misoprostol for cervical preparation prior to D&E and may offer benefits for clinic flow and patient experience.

Progesterone after mifepristone: A pilot prospective single arm clinical trial for women who have changed their mind after commencing medical abortion.

AIM: This pilot study aimed to assess the utility of an oral progesterone treatment protocol for women who commenced medical abortion and then changed their mind and wished instead to maintain their pregnancy. METHODS: The Progesterone-After-Mifepristone-pilot for efficacy and reproducibility (PAMper) trial was designed as a prospective single-arm pilot clinical trial, conducted via telehealth. Women aged 18 to 45 years in Australia who reported ingesting mifepristone within the last 72 h to initiate medical abortion and had not taken misoprostol were included. Initial contact was by a web-based form. Following informed consent, participants were prescribed oral progesterone to be taken 400 mg twice per day for 3 days then 400 mg at night until completion of a 19 day course. Pregnancy viability was assessed by ultrasound scan after 14 days of progesterone treatment. RESULTS: Between October 2020 and June 2021, nine women contacted the PAMper trial, of whom six enrolled and commenced progesterone treatment. These women reported ingesting mifepristone at 40-70 days of gestation, with progesterone being commenced within 5.7-72 h of mifepristone ingestion. Five participants had ongoing, live pregnancies at the primary endpoint (ultrasound at >2 weeks). One participant had a miscarriage after 9 days of progesterone treatment. There were no clinically significant adverse events. CONCLUSION: This small study demonstrated a clinically sound protocol for researching the use of progesterone-after-mifepristone for women in this circumstance. Results of this pilot study support the need for further larger scale trials in this field.

Repositioning of mifepristone as an integrated stress response activator to potentiate cisplatin efficacy in non-small cell lung cancer.

Lung cancer, primarily non-small-cell lung cancer (NSCLC), is a significant cause of cancer-related mortality worldwide. Cisplatin-based chemotherapy is a standard treatment for NSCLC; however, its effectiveness is often limited due to the development of resistance, leading to NSCLC recurrence. Thus, the identification of effective chemosensitizers for cisplatin is of paramount importance. The integrated stress response (ISR), activated by various cellular stresses and mediated by eIF2α kinases, has been implicated in drug sensitivity. ISR activation globally suppresses protein synthesis while selectively promoting the translation of ATF4 mRNA, which can induce pro-apoptotic proteins such as CHOP, ATF3, and TRIB3. To expedite and economize the development of chemosensitizers for cisplatin treatment in NSCLC, we employed a strategy to screen an FDA-approved drug library for ISR activators. In this study, we identified mifepristone as a potent ISR activator. Mifepristone activated the HRI/eIF2α/ATF4 axis, leading to the induction of pro-apoptotic factors, independent of its known role as a synthetic steroid. Our in vitro and in vivo models demonstrated mifepristone's potential to inhibit NSCLC re-proliferation following cisplatin treatment and tumor growth, respectively, via the ISR-mediated cell death pathway. These findings suggest that mifepristone, as an ISR activator, could enhance the efficacy of cisplatin-based therapy for NSCLC, highlighting the potential of drug repositioning in the search for effective chemosensitizers.

Reversal of medication abortion with progesterone: a systematic review.

BACKGROUND: We sought to determine whether there is evidence to recommend progesterone for individuals not wishing to complete a medication abortion after taking mifepristone. METHODS: We undertook an updated systematic review including a primary search for studies in which individuals received progesterone to reverse the effects of mifepristone, and a secondary search for studies in which individuals received mifepristone alone. We searched PubMed, Embase, Cochrane, CINAHL and grey literature up to December 2022. We used the Joanna Briggs Institute critical appraisal tools for risk of bias assessment. We compared ongoing pregnancy rates among individuals treated with progesterone to those managed expectantly. RESULTS: We did not find new studies in our secondary search. For the main search, we included three case series and one randomised controlled trial. Data were available for 561 individuals who received progesterone after mifepristone, of whom 271 (48%) had ongoing pregnancies. The quality of the evidence in the case series was low due to methodological and ethical issues. Enrollment in the randomised trial stopped early due to bleeding events in both arms. The ongoing pregnancy rate for individuals ≤7 weeks who received progesterone was 42% (95% CI 37-48) compared with 22% (95% CI 11-39) for mifepristone alone. At 7-8 weeks, the ongoing pregnancy rate was 62% (95% CI 52-71) in the progesterone group and 50% (95% CI 15- 85) in the mifepristone alone group. CONCLUSION: Based mostly on poor-quality data, it appears the ongoing pregnancy rate in individuals treated with progesterone after mifepristone is not significantly higher compared to that of individuals receiving mifepristone alone.

Steroid profile in patients with breast cancer and in mice treated with mifepristone.

Progesterone receptors (PRs) are biomarkers used as prognostic and predictive factors in breast cancer, but they are still not used as therapeutic targets. We have proposed that the ratio between PR isoforms A and B (PRA and PRB) predicts antiprogestin responsiveness. The MIPRA trial confirmed the benefit of 200 mg mifepristone, administered to patients with tumors with a high PRA/PRB ratio, but dose-ranging has not been conducted. The aim of this study was to establish the plasma mifepristone levels of patients from the MIPRA trial, along with the resultant steroid profiles, and compare these with those observed in mifepristone-treated mice using therapeutic schemes able to induce the regression of experimental mammary carcinomas with high PRA/PRB ratios: 6 mg pellets implanted subcutaneously, or daily doses of 12 mg/kg body weight. The plasma levels of mifepristone and other 19 plasma steroids were measured by liquid chromatography-tandem mass spectometry. In mifepristone-treated mice, plasma levels were lower than those registered in mifepristone-treated patients (i.e. day 7 after treatment initiation, pellet-treated mice: 8.4 ± 3.9 ng/mL; mifepristone-treated patients: 300.3 ± 31.7 ng/mL (mean ± s.d.; P < 0.001)). The increase in corticoid related steroids observed in patients was not observed in mifepristone-treated mice. The increase in progesterone levels was the most significant side effect detected in mifepristone-treated mice after 14 or 21 days of treatment, probably due to an ovarian compensatory effect not observed in postmenopausal patients. We conclude that in future clinical trials using mifepristone, the possibility of lowering the standard daily dose of 200 mg should be considered.

Monitoring Glucocorticoid Receptor in Plasma-derived Extracellular Vesicles as a Marker of Resistance to Androgen Receptor Signaling Inhibition in Prostate Cancer.

Disease progression following androgen ablation was shown to be associated with upregulation of the glucocorticoid receptor (GR). Longitudinal monitoring of GR expression in circulating extracellular vesicles (EV) may reflect changes in the tumor cell and facilitates detection of acquired resistance. We utilized LNCaP, LREX cells and a patient-derived xenograft, MDA PDX 322-2-6a, for in vitro and in vivo experiments. Plasma-derived EVs were isolated from patients with localized high-risk prostate cancer undergoing androgen ablation. The mRNA levels of GR in EVs and their responsive genes were detected by transcriptome analysis, qRT-PCR and the protein levels by Western blot analysis. We detected changes in GR expression at mRNA and protein levels in EVs derived from LNCaP and LREX cells in in vitro studies. In in vivo experiments, LNCaP and the PDX MDA 322-2-6a-bearing mice were treated with enzalutamide. GR levels in plasma-derived EVs were increased only in those tumors that did not respond to enzalutamide. Treatment of mice bearing enzalutamide-resistant tumors with a GR inhibitor in combination with enzalutamide led to a transient pause in tumor growth in a subset of tumors and decreased GR levels intracellular and in plasma-derived EVs. In a subgroup of patients with high-risk localized prostate cancer treated with androgen signaling inhibition, GR was found upregulated in matching tissue and plasma EVs. These analyses showed that GR levels in plasma-derived EVs may be used for monitoring the transition of GR expression allowing for early detection of resistance to androgen ablation treatment. SIGNIFICANCE: Longitudinal monitoring of GR expression in plasma-derived EVs from patients with prostate cancer treated with androgen signaling inhibitors facilitates early detection of acquisition of resistance to androgen receptor signaling inhibition in individual patients.

Cocktail treatment by GnRH-antagonist, letrozole, and mifepristone for the prevention of ovarian hyperstimulation syndrome: a prospective randomized trial.

OBJECTIVE: This study is aimed to determine the efficacy of a cocktail style treatment by combining GnRH-antagonist, letrozole, and mifepristone on the prevention of ovarian hyperstimulation syndrome (OHSS) in high-risk women. METHODS: This prospective, randomized controlled clinical trial was performed between January 2018 and December 2018. A total of 170 women who identified as high risk of OHSS during the ovarian hyperstimulation and underwent cryopreservation of whole embryos. On the day of oocyte retrieval, the combination group received 0.25 mg Cetrorelix for 3 d, 5 mg letrozole for 5 d, and 50 mg mifepristone for 3 d, the mifepristone group received 50 mg mifepristone for 3 d. A total of 156 cases were included in final analysis. All the frozen embryo transfer (FET) cycles were followed up until December 2021. RESULTS: The combination group showed significantly decreased incidence of moderate and severe OHSS than mifepristone group (20.5% vs. 42.3%), with remarkably reduced serum estradiol level on hCG + 3 and + 5 d, decreased ovarian diameter, and shortened luteal phase. Oocyte retrieval number, levels of estradiol on hCG + 0 and VEGF, and ovarian diameter on hCG + 5 were associated with the severity of the symptoms. There was no significant difference in cumulative live birth rates (LBRs) between the combination and mifepristone group (74.4% vs. 76.9%). CONCLUSIONS: The combination treatment effectively reduces the incidence of moderate/severe OHSS in high-risk women.

Medical abortion in the second trimester - an update.

The safety and efficacy of medical abortion in the second trimester is provider independent and may therefore offer advantages over surgical second trimester abortion in certain settings. Due to bleeding risk, medical abortions in the second trimester are still mostly performed in a clinic or hospital setting. The most effective regimen for abortion includes pretreatment with oral mifepristone and following doses of misoprostol. An alternative is misoprostol only which should only be used when mifepristone is not available. The optimal dosing of prostaglandin to achieve the highest efficacy with the lowest proportion of complications remains to be established. Complications are rare and serious adverse events uncommon but may include uterine rupture especially in women with a previous cesarean delivery or uterine surgery. Women having second trimester medical abortion are a diverse group with different indications for the abortion. All women should be offered pain relief and respectful care. Staff involved in second trimester medical abortion often find their work challenging. At the same time, staff indicate pride and a conviction of contributing to the 'greater good' for women and society. Staff involved in second trimester abortion should be offered guidance and support through the employer. Post abortion contraception should be offered to all women having second trimester medical abortions, including those who have the abortion due to fetal malformation. All methods of contraception can be started immediately after a second trimester medical abortion except for cycle based methods and diaphragms.

Fertility preservation in pregnant cancer patients after first-trimester abortion: a new challenge with possible solutions.

Fertility preservation in pregnant women recently diagnosed with cancer can be a challenge. Raised levels of human chorionic gonadotropin (Beta-hCG) and progesterone in this population of patients may pose a problem for the prompt initiation of controlled ovarian stimulation (COS) due to a potential negative feedback of these hormones on folliculogenesis; however, it is not feasible to wait for negativization of serum beta-hCG levels before starting controlled ovarian stimulation. In literature, very few cases have been reported regarding the preservation of fertility in pregnant women recently diagnosed with cancer. We performed an extended revision of the literature to evaluate the current knowledge of the management of fertility preservation in women with cancer and we examined two cases closely. The first case study involved a cancer patient who underwent surgical abortion at 6.5 weeks of gestation followed by administration of mifepristone to detach any minimal residual trophoblast and consequently to decrease serum beta-hCG and progesterone levels before starting COS. In the second case study, the cancer patient underwent surgical abortion at 7.1 weeks of gestation and simultaneous unilateral oophorectomy for ovarian tissue cryopreservation due to a limited time for COS. By analyzing the results of these studies, it could be hypothesized that mifepristone administration may favor the decrease of serum beta-hCG and progesterone levels in order to permit rapid initiation of COS. In cases where COS is not feasible, ovarian tissue cryopreservation should be considered as an alternative fertility preservation technique.

Uso de mifepristona en embarazo ectópico intersticial: un reporte de caso / Use of mifepristone in an interstitial ectopic pregnancy: a case report

Introducción: El embarazo ectópico intersticial es una forma de presentación poco frecuente, con una incidencia del 2-4% de los embarazos ectópicos; sin embargo, a pesar de su baja incidencia la mortalidad es cinco veces mayor, impactando en las cifras de mortalidad materna y representando en torno al 10-15% de los casos. Objetivo: Presentar un caso de embarazo ectópico intersticial, cuya ocurrencia es poco frecuente, así como el abordaje satisfactorio del manejo médico con mifepristona y metotrexato. Caso clínico: Mujer de 28 años con antecedente de resección tubárica por quiste paraovárico derecho, quien acudió a urgencias por hallazgo en ecografía obstétrica de sospecha de embarazo intersticial izquierdo y se le administró manejo farmacológico con dosis de metotrexato y mifepristona, con éxito. Conclusiones: El manejo médico con metotrexato y mifepristona para el embarazo ectópico intersticial parece ser una elección eficaz en los casos con estabilidad hemodinámica y deseo de conservación de la fertilidad.

Background: Interstitial ectopic pregnancy represents a rare form of presentation, with an incidence of 2-4% of all ectopic pregnancies. However, despite its low incidence, it is associated with a five-fold increase in mortality, significantly impacting maternal mortality rates, accounting for approximately 10-15% of cases. Objective: To present a case of interstitial ectopic pregnancy, which is a rare occurrence, as well as the successful medical management approach with mifepristone and methotrexate. Case report: A 28-year-old women with a history of right paraovarian cyst tubal resection presented to the emergency department due to suspected left interstitial pregnancy identified on obstetric ultrasound. The patient was successfully managed with pharmacological treatment using doses of methotrexate and mifepristone. Conclusions: Medical management with methotrexate and mifepristone for interstitial ectopic pregnancy appears to be an effective choice in cases with hemodynamic stability and a desire for fertility preservation.

Evaluating the neuroprotective effects of progesterone receptors on experimental traumatic brain injury: The PI3K/Akt pathway.

BACKGROUND: Studies have confirmed the salutary effects of progesterone (P4) on traumatic brain injury (TBI). This study investigated the beneficial effects of P4 via its receptors on TBI, and also whether progesterone receptors (PRs) can modulate TBI through PI3K/Akt pathway. MATERIAL AND METHODS: Marmarou method was utilized to induce diffuse TBI in ovariectomized rats. P4 (1.7 mg/kg) or the vehicle (oil) was administered 30 min after TBI induction. Moreover, RU486 (PR antagonist) and its vehicle (DMSO) were injected before TBI induction and P4 injection. Brain Evans blue content, brain water content (WC), various oxidative stress parameters, IL-1ß levels, tumor necrosis factor-α (TNF-α), histopathological alterations, and also phosphorylated Akt (p-Akt) and PI3K expressions in the brain were assessed 24 h after TBI. The veterinary comma scale (VCS) was measured before and after TBI at different times. RESULTS: The findings revealed that P4 caused an increase in VCS and a decrease in brain WC, oxidative stress, TNF-α and IL-1ß levels. RU486 inhibited the beneficial effects of P4 on these indices. Moreover, RU486 prevented the reduction of brain edema, inflammation, and apoptosis caused by P4. Moreover, P4 following TBI increased the expression of PI3K/p-Akt protein in the brain. RU486 eliminated the effects of P4 on PI3K/p-Akt expression. CONCLUSION: According to these findings, PRs are acting as critical mediators for the neuroprotective properties of P4 on oxidative stress, pro-inflammatory cytokine levels, and neurological outcomes. PRs also play an important role in regulating the PI3K/p-Akt expression and nongenomic function of P4.

Next step in the development of mesoprogestins: the preclinical profile of EC313.

Introduction: The pharmacological target for progesterone, different progestins, and Selective Progesterone Receptor Modulators (SPRMs) is the nuclear progesterone receptor (PR). EC313 is a new member of a subgroup of SPRMs, mesoprogestins, which combine especially PR- agonistic and PR-antagonistic activities in one molecule. Methods: The suitable in vivo-model for the differentiation of SPRMs from the subgroup of mesoprogestins is the estrogen-primed juvenile rabbit endometrium assay (McPhail Assay). Remarkably, in contrast to other well-known SPRMs with no agonistic effects in this test, EC313 shows clear partial PR-agonistic effects that are higher than that of the well-known mesoprogestin Asoprisnil which already demonstrated remarkable clinical effectiveness for the treatment of uterine fibroids and endometriosis. The findings from the guinea pig studies presented here can be the impetus for further preclinical development of EC313. This model shows the same features for the termination of pregnancy by antiprogestins such as Mifepristone and Ulipristal acetate (UPA) in humans. Moreover, it is possible to distinguish between progestational and anti-progestational activities in the same experiment. Results: The EC313 treatment reveals PR dominance in the genital tract and inhibits unopposed estrogenic effects. In very high doses (30.0 mg/animal/day subcutaneously (s.c.)) given twice on pregnancy days 43 and 44, no premature labor was induced (in contrast to UPA, dosed at 10.0 and 30. mg/animal/day s.c.). The anti-ovulatory activity of EC313 exceeds that of Ulipristal acetate or Mifepristone. EC313 binds to the steroid receptors in vitro with a similar affinity as the natural ligand progesterone. At the glucocorticoid receptor (GR) EC313 acts as a weak inhibitor. Minor activities at the human androgen receptor (AR) and mineralocorticoid receptor (MR) are considered negligible. No binding to the estradiol receptor was detected. In contrast to some in vitro-receptor findings, estrogenic, anti-estrogenic, androgenic, anti-androgenic, glucocorticoid, and anti-glucocorticoid actions were absent in vivo. The tissue selectivity of EC313 was demonstrated previously by reducing the growth and proliferation of uterine fibroids in animal models (lowest effective dosage 0.1 mg/kg/day s.c.).. As shown in this article, the anti-fibroid activity of EC313 was confirmed with a 10 times lower dosage (0.01 mg/kg/day s.c.). It was also shown that EC313 reduces the growth of endometriotic lesions in a human xenograft immune-deficient (NOD-SCID) mice model with a comparatively very low dosage range. In the aforementioned EC313 activity model, UPA was tested as the reference compound, the clinical effectiveness of which has already been demonstrated. Discussion: For an explanation of these findings, the possibility is discussed that the mixed agonistic/antagonistic feature of EC313 is tissue target-specific based on its super-additive synergism characteristic for active bifunctional agents. In conclusion, the specific pharmacodynamic profile of this compound opens the possibility for the development of a drug with a distinct pharmaco-endocrinological profile against uterine fibroids, endometriosis, and other PR-dependent gynecological diseases.

Effects of mifepristone, a model compound with anti-progestogenic activity, on the development of African clawed frog (Xenopus laevis).

The objective of this study was to assess the effects of a model substance with anti-progestogenic activity on development of African clawed frog (Xenopus laevis) from tadpole to juvenile stage. Mifepristone, a synthetic progesterone receptor-blocking steroid hormone used in medicine as an abortifacient, was chosen as a model compound with anti-progestogenic activity. In the experiment, African clawed frog tadpoles were exposed to mifepristone at three concentrations (2, 21, and 215 ng L-1). A control group was exposed to dimethyl sulfoxide (DMSO; 0.001 %). The experiment started when tadpoles reached stages 47-48 according to Nieuwkoop and Faber (NF; 1994) and continued until stage NF 66, when metamorphosis was complete. Exposure to mifepristone had no significant effect on the rate of tadpole development, occurrence of morphological anomalies, weight, body length, or sex ratio. Mortality was within an acceptable range of 0-3.6 % throughout the test and did not differ among the groups. Histopathological examination of the gonads and thyroid gland revealed no significant changes. Therefore, we can conclude that mifepristone had no negative effect on development of the African clawed frog up to juvenile stage. Nevertheless, at the highest tested mifepristone concentration (215 ng L-1), gene expression analysis revealed up-regulation of mRNA expression of nuclear progesterone receptor (npr), membrane progesterone receptor (mpr), estrogen receptor beta (esrß), and luteinizing hormone (lh) in the brain-pituitary complex of exposed frogs at stage NF 66. Higher mRNA expression of npr was also found in frogs exposed to 22 ng L-1 mifepristone compared to the solvent control. These findings confirmed the anti-progestogenic activity of mifepristone in frogs because the up-regulation of progesterone receptors occurs if progesterone availability in the body is reduced. All the observed changes in combination may have negative consequences for reproduction and reproductive behavior later in life.

Randomized controlled trial comparing efficacy of a combination regime containing two cervical sensitizers (mifepristone + Foley's catheter) versus single agent mifepristone or Foley's catheter for labor induction in women attempting TOLAC at late third trimester with a dead fetus in utero.

Randomized controlled trial comparing efficacy of a combination regime containing two cervical sensitizers (mifepristone + Foley's catheter) versus single agent mifepristone or Foley's catheter for labor induction in women attempting TOLAC at late third trimester with a dead fetus in utero. AIM: To compare efficacy and safety of a new combination regime comprising of two cervical sensitizers used simultaneously with single agents, for labor induction in women attempting TOLAC at ≥34 weeks' gestation with a dead fetus. METHOD: This was a multiarm randomized controlled trial (RCT) where participants received one of the three regimes-single agent oral Mifepristone 200 mg, intracervical Foley's catheter (16 Fr size, filled with 40 mL normal saline after intracervical instillation), and combination regime consisting of both used simultaneously. Number of women undergoing vaginal birth within 48 h of induction (VB48 ) was the primary outcome compared between groups. RESULTS: VB48 was higher in participants on combination regime in comparison to participants on Foley's catheter (54 vs. 42). Total vaginal births were higher in participants on combination regime compared to both single agents (58 vs. 48 and 44). Duration and dose of oxytocin augmentation was lower in participants on combination regime compared to both single agents. Induction birth interval was short in participants on combination regime compared to those on Foley's catheter. Maternal complications between groups were similar. CONCLUSION: Combination of cervical sensitizers for labor induction in late third trimester among women with dead fetus attempting TOLAC resulted in higher proportion of vaginal births and might reduce risk of scar dehiscence due to requirement of a lower dose of oxytocin for augmentation.