Bioequivalence of Elagolix/Estradiol/Norethindrone Acetate Fixed-Dose Combination Product: Phase 1 Results in Healthy Pre- and Postmenopausal Women.

Fixed-dose combination (FDC) therapies can enhance patient convenience and adherence to prescribed treatment regimens. Elagolix is a novel oral gonadotropin-releasing hormone receptor antagonist approved for management of moderate to severe pain associated with endometriosis and heavy menstrual bleeding associated with uterine fibroids. Hormonal add-back therapy can attenuate the reversible hypoestrogenic effects of elagolix. An FDC formulation containing elagolix/estradiol (E2)/norethindrone acetate (NETA) 300/1/0.5 mg as the morning dose and an elagolix 300 mg capsule as the evening dose, were evaluated in 2 bioequivalence studies including the effects of food. Study 1 in premenopausal women assessed the bioavailability of the elagolix 300-mg capsule relative to the commercially available elagolix 300-mg tablet. Study 2 in postmenopausal women, elagolix/E2/NETA (300 mg/1 mg/0.5 mg) FDC capsule was assessed relative to the elagolix 300-mg tablet coadministered with E2/NETA 1-mg/0.5-mg tablet, the regimen that was studied in Phase 3 uterine fibroid studies. Under fasting conditions, the test elagolix 300-mg capsule was bioequivalent to the reference elagolix 300-mg tablet. Under fasting conditions, the elagolix/E2/NETA FDC capsule was bioequivalent to the coadministered elagolix 300-mg tablet and E2/NETA 1/0.5-mg tablet. Following administration of elagolix/E2/NETA FDC capsule after a high-fat breakfast, elagolix mean maximum concentration (Cmax) and area under the plasma concentration-time curve (AUC) were 38% and 28% lower, relative to fasting conditions. NETA mean Cmax was 51% lower and AUC from time 0 to infinity was 20% higher, while baseline-adjusted total estrone mean Cmax and AUC were 46% and 14% lower, respectively. No safety concerns were identified. These results enabled bridging the elagolix/E2/NETA FDC capsule.

Effects of low-dose insulin or a soluble guanylate cyclase activator on lower urinary tract dysfunction in streptozotocin-induced diabetic rats.

AIMS: To examine the effects of low-dose insulin or a soluble guanylate cyclase activator (sGC) on lower urinary tract dysfunction (LUTD) in rats with diabetes mellitus (DM). MAIN METHODS: Female Sprague-Dawley rats were divided into non-DM control (N), DM induced by streptozotocin (65 mg/kg), with low-dose insulin (DI), DM with vehicle (D), and DM with sGC (GC) groups. In GC group, BAY 60-2770 (1 mg/kg/day) was orally administered in 6-8 weeks after DM. Voiding assay at 2, 4, and 8 weeks after DM, cystometry, and urethral pressure recordings at 8 weeks of DM were performed. mRNA levels of NO-related markers and cGMP protein levels in the urethra, and ischemia and inflammation markers in the bladder were evaluated by RT-PCR. KEY FINDINGS: Moderate levels of high blood glucose were maintained in Group DI versus Group D. The 24-h voided volume was significantly higher in Group D versus Groups N and DI. Non-voiding contractions were significantly greater, and voiding efficiency and urethral pressure reduction were significantly lower in Group D versus Groups N, DI, and GC. Urethral cGMP levels were significantly lower in Group D versus Groups N and GC. mRNA levels of PDE5 in the urethra and ischemia and inflammation markers in the bladder increased in Group D versus Group N or DI was reduced after sGC treatment. SIGNIFICANCE: DI rats with a lesser degree of bladder and urethral dysfunction might be useful as a slow-progressive DM model. sGC activation could be an effective treatment of LUTD in DM.

Elagolix in the treatment of heavy menstrual bleeding associated with uterine fibroids in premenopausal women.

INTRODUCTION: Uterine fibroids (UFs) are the most common benign tumor arising from myometrium of reproductive age women, with significant financial burden estimated in hundreds of billions of dollars. Unfortunately, there are limitations in available long-term treatment options. Thus, there is a large unmet need in the UF space for noninvasive therapeutics. AREAS COVERED: Authors reviewed the literature available for elagolix; an orally bioavailable, second-generation, non-peptide gonadotropin-releasing hormone (GnRH) antagonist recently approved by the US Food and Drug Administration (FDA) in combination with estradiol/norethindrone acetate for the management of heavy menstrual bleeding associated with UFs in premenopausal women. EXPERT OPINION: The utility of new-generation oral GnRH-antagonists, such as elagolix, relugolix and linzagolix, is offering a new potential opportunity for the future therapy of UFs: elagolix has been the most studied drug of this class for treating benign gynecological diseases, including endometriosis and UFs, for which it has been US FDA-approved in 2018 and 2020, respectively.

Oxidative stress and Liver X Receptor agonist induce hepatocellular carcinoma in Non-alcoholic steatohepatitis model.

BACKGROUND AND AIM: The incidence of non-alcoholic steatohepatitis (NASH)-related hepatocellular carcinoma (HCC) is progressively increasing. However, the pathophysiology and etiology of NASH progression to HCC are unknown. We hypothesized that steatosis was the key factor in NASH-related hepatocarcinogenesis and aimed to evaluate the effects of long-term liver X receptor (LXR) agonist stimulation on hepatic steatosis induced by a high-fat diet and oxidative stress. METHODS: We used an LXR agonist (T0901317) and CCl4 to induce hepatic steatosis and oxidative stress, respectively. C57BL/6 mice fed with a high-fat diet were treated with either T0901317 + CCl4 (T09 + CCl4 group) or CCl4 alone (CCl4 group). T0901317 (2.5 mg/kg) and CCl4 (0.1 mL/kg) were intraperitoneally administered twice weekly for 24 weeks. RESULTS: The liver-to-body weight ratio was significantly higher in the T09 + CCl4 group than in the CCl4 group. Mice in the T09 + CCl4 group exhibited abnormal lipid metabolism and NASH-like histopathological features. Additionally, all mice in the T09 + CCl4 group developed liver tumors diagnosed as well-differentiated HCC. The genes identified via microarray analysis were related to NASH and HCC development. CONCLUSIONS: By combining long-term LXR agonist stimulation with oxidative stress and a high-fat diet, we successfully reproduced liver conditions in mice similar to those in humans with NASH and progression to HCC. Our results provide new insight into NASH-related HCC progression and therapy.

A Personalized Medicine Approach Using Clinical Utility Index and Exposure-Response Modeling Informed by Patient Preferences Data.

Selection of a personalized dose for an individual patient can be informed by the patient's preferences, translated as weights on each of the clinically relevant safety and efficacy drug attributes, based on results from a brief patient preference elicitation questionnaire. In this analysis, the weighted attributes were simulated to represent various endometriosis patient profiles. Exposure-response simulations were performed for elagolix, a drug approved for management of moderate to severe pain associated with endometriosis, across a range of plasma exposures corresponding to a range of doses. The results were combined to calculate a personalized clinical utility index. An interactive user-friendly online application was developed and envisioned as a physician's desk tool to personalize the dose selection process based on individual patient preferences. This demonstration should serve as an example of how patient/physician conversation can be facilitated with quantitative tools for personalizing the dose.

Patient preferences for elagolix and leuprolide for treating endometriosis-related pain in the United States.

INTRODUCTION: We evaluated elagolix and leuprolide from the patient's perspective for the treatment of endometriosis-related pain. AREA COVERED: Preference weights from a published discrete choice experiment were used to evaluate preferences for treatment profiles simulating elagolix (150 mg/day and 200 mg/twice-daily dosages) and leuprolide for the treatment of moderate to severe endometriosis-related pain. Sensitivity analyses were conducted by varying the range of risk for pregnancy-related problems, moderate to severe hot flashes, and bone fracture across scenarios. EXPERT OPINION: The 200 mg twice daily dosage of elagolix is more likely to be preferred over leuprolide by patients with moderate to severe endometriosis-related pain in all scenarios explored in the evaluation and sensitivity analyses. The probability that an average respondent would select a treatment was sensitive to increases in risk of moderate to severe hot flashes for leuprolide and possible variations in the risk of pregnancy-related problems for both treatments but was not influenced by an increased risk of bone fracture. CONCLUSIONS: Patients' preferences for treatment of endometriosis-related pain should be evaluated using the benefits and risks of each pharmacological option. Respondents were more likely to prefer the treatment profile similar to 200 mg twice daily elagolix over that of leuprolide in all scenarios.

Development of Aggregation-Caused Quenching Probe-Loaded Pressurized Metered-Dose Inhalers with Fluorescence Tracking Potentials.

Recently, pressurized metered-dose inhalers (pMDIs) are getting more attention as an effective approach of pulmonary drug delivery, and nanoparticle-based formulations have become a new generation of pMDIs, especially for water insoluble drugs. Up until now, there is no clinical application of nanoparticle-based pMDIs. The main hurdle remains in the lack of knowledge of the in vivo fate of those systems. In this study, a fluorescent probe named P4 with aggregation-caused quenching (ACQ) effect was loaded in the nanoparticle-based pMDIs to track the in vivo fate. P4 probe expressed strong fluorescence when distributed in intact nanoparticles, but quenched in the in vivo aqueous environment due to molecular aggregation. Experimentally, P4 probe was encapsulated into solid lipid nanoparticles (SLN) as P4-SLN, and then, the formulation of pMDIs was optimized. The content (w/w) of the optimal formulation (P4-SLN-pMDIs) was as follows: 6.02% Pluronic® L64, 12.03% ethanol, 0.46% P4-SLN, and 81.49% 1,1,1,2-tetrafluoroethane (HFA-134a). P4-SLN-pMDI was transparent in appearance, possessed a particle size of 132.07 ± 3.56 nm, and the fine particle fraction (FPF) was 39.53 ± 1.94%, as well good stability was shown within 10 days. The results indicated P4-SLN-pMDI was successfully prepared. Moreover, the ACQ property of P4-SLN-pMDIs was verified, which ensured the fluorescence property as a credible tool for in vivo fate study. Taken together, this work established a platform that could provide a firm theoretical support for exploration of the in vivo fate of nanoparticle-based pMDIs in subsequent studies. Grapical abstract.

Assessment of Clinical Drug-Drug Interactions of Elagolix, a Gonadotropin-Releasing Hormone Receptor Antagonist.

Elagolix is an oral gonadotropin-releasing hormone receptor antagonist indicated for the management of endometriosis-associated pain and in combination with estradiol/norethindrone acetate indicated for the management of heavy menstrual bleeding associated with uterine leiomyomas (fibroids) in premenopausal women. Elagolix coadministered with estradiol/norethindrone acetate is in late-stage development for the management of heavy menstrual bleeding associated with uterine fibroids. Based on the in vitro profile of elagolix metabolism and disposition, 9 drug-drug interaction (DDI) studies evaluating the victim and perpetrator characteristics of elagolix were conducted in 144 healthy volunteers. As a victim of cytochrome P450 (CYPs) and transporter-mediated DDIs, elagolix area under the curve (AUC) increased by ∼2-fold following coadministration with ketoconazole and by ∼5- and ∼2-fold with single and multiple doses of rifampin, respectively. As a perpetrator, elagolix decreased midazolam AUC (90% confidence interval) by 54% (50%-59%) and increased digoxin AUC by 32% (23%-41%). Elagolix decreased rosuvastatin AUC by 40% (29%-50%). No clinically significant changes in exposure on coadministration with sertraline or fluconazole occurred. A elagolix 150-mg once-daily regimen should be limited to 6 months with strong CYP3A inhibitors and rifampin because of the potential increase in bone mineral density loss, as described in the drug label. A 200-mg twice-daily regimen is recommended for no more than 1 month with strong CYP3A inhibitors and not recommended with rifampin. Elagolix is contraindicated with strong organic anion transporter polypeptide B1 inhibitors (eg, cyclosporine and gemfibrozil). Consider increasing the doses of midazolam and rosuvastatin when coadministered with elagolix, and individualize therapy based on patient response. Clinical monitoring is recommended for P-glycoprotein substrates with a narrow therapeutic window (eg, digoxin). Dose adjustments are not required for sertraline, fluconazole, bupropion (or any CYP2B6 substrate), or elagolix when coadministered.

E. coli nitroreductase NfsA is a reporter gene for non-invasive PET imaging in cancer gene therapy applications.

The use of reporter genes to non-invasively image molecular processes inside cells has significant translational potential, particularly in the context of systemically administered gene therapy vectors and adoptively administered cells such as immune or stem cell based therapies. Bacterial nitroreductase enzymes possess ideal properties for reporter gene imaging applications, being of non-human origin and possessing the ability to metabolize a range of clinically relevant nitro(hetero)cyclic substrates. Methods: A library of eleven Escherichia coli nitroreductase candidates were screened for the ability to efficiently metabolize 2-nitroimidazole based positron emission tomography (PET) probes originally developed as radiotracers for hypoxic cell imaging. Several complementary methods were utilized to detect formation of cell-entrapped metabolites, including various in vitro and in vivo models to establish the capacity of the 2-nitroimidazole PET agent EF5 to quantify expression of a nitroreductase candidate. Proof-of-principle PET imaging studies were successfully conducted using 18F-HX4. Results: Recombinant enzyme kinetics, bacterial SOS reporter assays, anti-proliferative assays and flow cytometry approaches collectively identified the major oxygen-insensitive nitroreductase NfsA from E. coli (NfsA_Ec) as the most promising nitroreductase reporter gene. Cells expressing NfsA_Ec were demonstrably labelled with the imaging agent EF5 in a manner that was quantitatively superior to hypoxia, in monolayers (2D), multicellular layers (3D), and in human tumor xenograft models. EF5 retention correlated with NfsA_Ec positive cell density over a range of EF5 concentrations in 3D in vitro models and in xenografts in vivo and was predictive of in vivo anti-tumor activity of the cytotoxic prodrug PR-104. Following PET imaging with 18F-HX4, a significantly higher tumor-to-blood ratio was observed in two xenograft models for NfsA_Ec expressing tumors compared to the parental tumors thereof, providing verification of this reporter gene imaging approach. Conclusion: This study establishes that the bacterial nitroreductase NfsA_Ec can be utilized as an imaging capable reporter gene, with the ability to metabolize and trap 2-nitroimidazole PET imaging agents for non-invasive imaging of gene expression.

Exposure-Safety Analyses Identify Predictors of Change in Bone Mineral Density and Support Elagolix Labeling for Endometriosis-Associated Pain.

Elagolix is a novel oral gonadotropin releasing hormone receptor antagonist, that can suppress estradiol in a dose-dependent manner. It is indicated for management of moderate-to-severe pain associated with endometriosis. A population exposure-response model describing the relationship between elagolix exposure and changes in bone mineral density (BMD) was developed using data from four phase III studies in premenopausal women with endometriosis-associated pain. Elagolix pharmacokinetic exposure-dependent changes in BMD were described by an indirect-response maximum effect (Emax ) model through stimulation of bone resorption. African American race, higher body mass index (BMI), and lower type-I collagen C-telopeptide concentrations were significantly associated with higher baseline BMD. Higher BMI was significantly associated with higher bone formation rates. Simulations using the final model demonstrated that elagolix 150 mg q.d. dosing for 24 months is predicted to result in -1.45% (-2.04 to -0.814) decrease from baseline in BMD and were used to support corresponding dosing recommendations in the label.

A new strategy for durable control of late blight in potato by a single soil application of an oxathiapiprolin mixture in early season.

Root treatment with oxathiapiprolin, benthiavalicarb or their mixture Zorvec-Endavia [ZE (3+7, w/w)] was shown to provide prolonged systemic protection against foliar oomycete pathogens attacking cucumber, tomato and basil. Here we report that these fungicides can effectively protect potato plants against late blight when applied to the soil in which such potato plants are grown. In two field experiments, performed in 2019 and 2020, potato plants grown in 64 L containers were treated with a soil drench of oxathiapiprolin, benthiavalicarb or ZE at 12.5, 25 or 50 mg ai/five plants in a container. Artificial inoculations with Phytophthora infestans revealed that such treated plants were protected against late blight in a dose-dependent manner all along the season. Interestingly, oxathiapiprolin persisted in the treated soil for at least 139 days, providing systemic protection against late blight to the following potato crops grown in that treated soils. Potato plants grown in loess soil in the field were either sprayed or drenched with ZE. Plants treated via the soil were significantly better protected against late blight compared to the plants treated by a spray. The data demonstrate a new strategy for season-long protection of potato against late blight by a single soil application of ZE. The systemic nature of oxathiapiprolin and benthiavalicarb composing ZE assures the translocation to the foliage of two fungicides with different modes of action. This shall minimize the risk of developing resistance against either fungicide in the treated crops.

The Climate is Changing for Metered-Dose Inhalers and Action is Needed.

Increases in global temperature are already having a significant impact on our climate. The hydrofluorocarbon (HFC) propellants used today in pressurized metered-dose inhalers (pMDIs) have global warming potential (GWP) many times that of carbon dioxide. Their use, together with all other emissive uses of HFCs, is being phased down under the Montreal protocol. This has prompted calls to switch patients to dry powder inhalers (DPIs). This paper presents a new analysis of the top 15 respiratory drug markets by drug class. It shows that a switch to DPIs would be economically feasible for most countries and most drugs. However, a wholesale switch of reliever medications, notably short-acting  ß-agonists, would lead to significant increases in the cost of these life-saving medications. Reviewing the evidence, whilst most patients are capable of using DPIs, the very young, very old and those undergoing an acute exacerbation still require a pMDI. Thus, there is a clinical and economic need to have both pMDIs and DPIs available. At the same time, it is projected that the reduction in non-medical uses of propellants is likely to give rise to a 5-fold increase in their cost for pMDI uses and is likely to hit the Western world in 2025. This may lead to a price increase in reliever medication that will make it unaffordable for the poorer communities in some markets. At the same time, opportunities to save money by developing new formulations using propellants with lower GWP, such as HFC 152a or HFO 1234ze(E), are described. Two companies have made this commitment, but neither currently have a strong presence in reliever medication. For them, or other companies, now is the time to act; 2025 is not far away in terms of product development timescales and the climate cannot wait.

Effect of Elagolix Exposure on Clinical Efficacy End Points in Phase III Trials in Women With Endometriosis-Associated Pain: An Application of Markov Model.

Elagolix is an oral gonadotropin-releasing hormone antagonist approved by the US Food and Drug Administration (FDA) for the management of moderate-to-severe pain associated with endometriosis and in combination with estradiol/norethindrone acetate approved for the management of heavy menstrual bleeding associated with uterine leiomyomas (fibroids) in premenopausal women. The objective of this work was to characterize the relationships between elagolix exposures and clinical efficacy response rates for dysmenorrhea (DYS) and nonmenstrual pelvic pain (NMPP) in premenopausal women enrolled in the pivotal phase III studies with moderate-to-severe pain associated with endometriosis. Relationships between elagolix average concentrations (Cavg ) and efficacy responses (DYS and NMPP) were characterized using a nonlinear mixed-effects discrete-time first order Markov modeling approach. Only age was statistically significant for NMPP but not considered clinically relevant. This work indicates that the selection of elagolix dose is not determined based on tested patient demographics, baseline, or endometriosis disease severity measures in covariate analysis. In other words, the work suggests no preference of one regimen over the other to treat endometriosis-associated pain (DYS or NMPP) for any patient subpopulation based on tested covariate groups.

The potential role of elagolix for treating uterine bleeding associated to uterine myomas.

INTRODUCTION: Uterine myomas represents a widespread gynecological disease of women in reproductive age. Although surgery remains the first choice for treating most patients, in the last years, new medical approaches have been considered in order to ameliorate heavy menstrual bleeding (HMB) related to their presence. Elagolix is a second-generation gonadotropin-releasing hormone (GnRH) antagonist under investigation for the long-term treatment of uterine myomas. AREAS COVERED: The aim of this drug evaluation is to give a complete overview of pharmacokinetic and pharmacodynamic data on elagolix for treating HMB related to uterine myomas and to report the results of the current clinical trials in this setting. EXPERT OPINION: In two previous phase II studies, this drug succeeded in ameliorating blood loss and quality of life of patients affected by uterine myomas with a good safety profile. Three phase III trials (ELARIS UF-I, UF-II, and EXTEND) investigated the efficacy, tolerability, and safety of elagolix at 300 mg twice daily with add-back therapy. The primary endpoint, consisting in the reduction in HMB compared to placebo, was met in the majority of patients under treatment. Currently, elagolix is under investigation in two other ongoing multicenter phase III clinical studies.

Phase I study of DFP-11207, a novel oral fluoropyrimidine with reasonable AUC and low Cmax and improved tolerability, in patients with solid tumors.

5-fluorouracil (5-FU) and 5-FU derivatives, such as capecitabine, UFT, and S-1, are the mainstay of chemotherapy treatment for gastrointestinal cancers, and other solid tumors. Compared with other cytotoxic chemotherapies, these drugs generally have a favorable safety profile, but hematologic and gastrointestinal toxicities remain common. DFP-11207 is a novel oral cytotoxic agent that combines a 5-FU pro-drug with a reversible DPD inhibitor and a potent inhibitor of OPRT, resulting in enhanced pharmacological activity of 5-FU with decreased gastrointestinal and myelosuppressive toxicities. In this Phase I study (NCT02171221), DFP-11207 was administered orally daily, in doses escalating from 40 mg/m2/day to 400 mg/m2/day in patients with esophageal, colorectal, gastric, pancreatic or gallbladder cancer (n = 23). It was determined that DFP-11207 at the dose of 330 mg/m2/day administered every 12 hours was well-tolerated with mild myelosuppressive and gastrointestinal toxicities. The pharmacokinetic analysis determined that the 5-FU levels were in the therapeutic range at this dose. In addition, fasted or fed states had no influence on the 5-FU levels (patients serving as their own controls). Among 21 efficacy evaluable patients, 7 patients had stable disease (33.3%), of which two had prolonged stable disease of >6 months duration. DFP-11207 can be explored as monotherapy or easily substitute 5-FU, capecitabine, or S-1 in combination regimens.

Elagolix Treatment for Up to 12 Months in Women With Heavy Menstrual Bleeding and Uterine Leiomyomas.

OBJECTIVE: To investigate the safety and efficacy of elagolix, an oral gonadotropin-releasing hormone antagonist, with hormonal add-back therapy for up to 12 months in women with heavy menstrual bleeding associated with uterine leiomyomas. METHODS: Elaris UF-EXTEND was a phase 3 extension study that evaluated an additional 6 months (up to 12 months total) of elagolix 300 mg twice daily with hormonal add-back therapy (estradiol 1 mg and norethindrone acetate 0.5 mg once daily) in women who completed an initial 6 months of the same treatment in one of two preceding phase 3 studies. The primary endpoint was the percentage of women with both less than 80 mL menstrual blood loss during final month and a 50% or greater reduction in menstrual blood loss from baseline to final month. Safety evaluations included adverse events and bone mineral density changes. The planned sample size of UF-EXTEND was based on estimated rollover and discontinuation rates in the two preceding studies. RESULTS: From September 2016 to March 2019, 433 women were enrolled in UF-EXTEND. Of these women, 218 received up to 12 months of elagolix with add-back therapy; the mean±SD age of this group was 42.4±5.4 years and 67.3% were black. The percentage of women who met the primary endpoint in this elagolix with add-back group was 87.9% (95% CI [83.4-92.3]). The most frequently reported adverse events with up to 12 months of elagolix plus add-back therapy were hot flush (6.9%), night sweats (3.2%), headache (5.5%), and nausea (4.1%). Mean percent decreases in bone mineral density from baseline to extension month 6 were significantly less with elagolix plus add-back therapy than with elagolix alone {between-group difference in lumbar spine: -3.3 (95% CI [-4.1 to -2.5])}. CONCLUSION: Up to 12 months of elagolix with add-back therapy provided sustained reduction in menstrual blood loss in women with uterine leiomyomas, with the addition of add-back therapy attenuating the hypoestrogenic effects of elagolix alone. No new or unexpected safety concerns were associated with an additional 6 months of elagolix with addback therapy. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, NCT02925494. FUNDING SOURCE: AbbVie Inc funded this study.

Reciprocal Regulation Between Forkhead Box M1/NF-κB and Methionine Adenosyltransferase 1A Drives Liver Cancer.

BACKGROUND AND AIMS: Forkhead box M1 (FOXM1) and nuclear factor kappa B (NF-ĸB) are oncogenic drivers in liver cancer that positively regulate each other. We showed that methionine adenosyltransferase 1A (MAT1A) is a tumor suppressor in the liver and inhibits NF-ĸB activity. Here, we examined the interplay between FOXM1/NF-κB and MAT1A in liver cancer. APPROACH AND RESULTS: We examined gene and protein expression, effects on promoter activities and binding of proteins to promoter regions, as well as effects of FOXM1 inhibitors T0901317 (T0) and forkhead domain inhibitory-6 (FDI-6) in vitro and in xenograft and syngeneic models of liver cancer. We found, in both hepatocellular carcinoma and cholangiocarcinoma, that an induction in FOXM1 and NF-κB expression is accompanied by a fall in MATα1 (protein encoded by MAT1A). The Cancer Genome Atlas data set confirmed the inverse correlation between FOXM1 and MAT1A. Interestingly, FOXM1 directly interacts with MATα1 and they negatively regulate each other. In contrast, FOXM1 positively regulates p50 and p65 expression through MATα1, given that the effect is lost in its absence. FOXM1, MATα1, and NF-κB all bind to the FOX binding sites in the FOXM1 and MAT1A promoters. However, binding of FOXM1 and NF-κB repressed MAT1A promoter activity, but activated the FOXM1 promoter. In contrast, binding of MATα1 repressed the FOXM1 promoter. MATα1 also binds and represses the NF-κB element in the presence of p65 or p50. Inhibiting FOXM1 with either T0 or FDI-6 inhibited liver cancer cell growth in vitro and in vivo. However, inhibiting FOXM1 had minimal effects in liver cancer cells that do not express MAT1A. CONCLUSIONS: We have found a crosstalk between FOXM1/NF-κB and MAT1A. Up-regulation in FOXM1 lowers MAT1A, but raises NF-κB, expression, and this is a feed-forward loop that enhances tumorigenesis.

Differential Role of Liver X Receptor (LXR) α and LXRß in the Regulation of UDP-Glucuronosyltransferase 1A1 in Humanized UGT1 Mice.

Liver X receptors (LXRs), LXRα and LXRß, are nuclear receptors that regulate the metabolism of cholesterol and bile acids and are activated by oxysterols. Humanized UGT1 (hUGT1) mice express the 9-human UGT1A genes associated with the UGT1 locus in a Ugt1-null background. The expression of UGT1A1 is developmentally delayed in the liver and intestines, resulting in the accumulation of serum bilirubin during the neonatal period. Induction of UGT1A1 in newborn hUGT1 mice leads to rapid reduction in total serum bilirubin (TSB) levels, a phenotype measurement that allows for an accurate prediction on UGT1A1 expression. When neonatal hUGT1 mice were treated by oral gavage with the LXR agonist T0901317, TSB levels were dramatically reduced. To determine the LXR contribution to the induction of UGT1A1 and the lowering of TSB levels, experiments were conducted in neonatal hUGT1/Lxrα -/- , hUGT1/Lxrß -/- , and hUGT1/Lxrαß -/- mice treated with T0901317. Induction of liver UGT1A1 was dependent upon LXRα, with the induction pattern paralleling induction of LXRα-specific stearoyl CoA desaturase 1. However, the actions of T0901317 were also shown to display a lack of specificity for LXR, with the induction of liver UGT1A1 in hUGT1/Lxrαß -/- mice, a result associated with activation of both pregnane X receptor and constitutive androstane receptor. However, the LXR agonist GW3965 was highly selective toward LXRα, showing no impact on lowering TSB values or inducing UGT1A1 in hUGT1/Lxrα -/- mice. An LXR-specific enhancer site on the UGT1A1 gene was identified, along with convincing evidence that LXRα is crucial in maintaining constitutive expression of UGT1A1 in adult hUGT1 mice. SIGNIFICANCE STATEMENT: It has been established that activation of LXRα, and not LXRß, is responsible for the induction of liver UGT1A1 and metabolism of serum bilirubin in neonatal hUGT1 mice. Although induction of the human UGT1A1 gene is initiated at a newly characterized LXR enhancer site, allelic deletion of the Lxrα gene drastically reduces the constitutive expression of liver UGT1A1 in adult hUGT1 mice. Combined, these findings indicate that LXRα is critical for the developmental expression of UGT1A1.

Clinical Pharmacology of Elagolix: An Oral Gonadotropin-Releasing Hormone Receptor Antagonist for Endometriosis.

The clinical pharmacology of elagolix was extensively evaluated in clinical studies in healthy subjects and in women with endometriosis. Elagolix pharmacokinetics (PK) show significant population variability, however they are minimally affected by patients' baseline characteristics and demographics, except for clinically relevant extrinsic and intrinsic factors such as coadministrated strong organic anion transporting polypeptide (OATP) 1B1 inhibitors and severe hepatic impairment, which are contraindications for the use of elagolix. These studies enabled a comprehensive understanding of elagolix mechanism of action and the downstream pharmacodynamic (PD) effects on gonadotropin and ovarian hormones, as well as full characterization of the PK/PD (PKPD) relationships of elagolix at various dosages, including the approved 150 mg once daily and 200 mg twice daily dosing regimens for the management of moderate to severe pain associated with endometriosis. Several model-based analyses have contributed to understanding of the benefit-risk profile of elagolix in patients with endometriosis, through characterization of the exposure relationship with responder rates, with changes in bone mineral density over time, as well as the interaction with coadministered drugs. Collectively, these studies and analyses served as supportive evidence for the effectiveness of the approved dosages and provided general dosing instructions of the first approved oral gonadotropin-releasing hormone receptor antagonist.