Efficacy and safety of ligelizumab in adults and adolescents with chronic spontaneous urticaria: results of two phase 3 randomised controlled trials.

BACKGROUND: Many patients with chronic spontaneous urticaria (CSU) do not achieve complete control of their symptoms with current available treatments. In a dose-finding phase 2b study, ligelizumab improved urticaria symptoms in patients with H1-antihistamine (H1-AH) refractory CSU. Here, we report the efficacy and safety outcomes from two ligelizumab phase 3 studies. METHODS: PEARL-1 and PEARL-2 were identically designed randomised, double-blind, active-controlled and placebo-controlled parallel-group studies. Patients aged 12 years or older with moderate-to-severe H1-AH refractory CSU were recruited from 347 sites in 46 countries and randomly allocated in a 3:3:3:1 ratio via Interactive Response Technology to 72 mg ligelizumab, 120 mg ligelizumab, 300 mg omalizumab, or placebo, dosed every 4 weeks, for 52 weeks. Patients allocated to placebo received 120 mg ligelizumab from week 24. The primary endpoint was change-from-baseline (CFB) in weekly Urticaria Activity Score (UAS7) at week 12, and was analysed in all eligible adult patients according to the treatment assigned at random allocation. Safety was assessed throughout the study in all patients who received at least one dose of the study drug. The studies were registered with ClinicalTrials.gov, NCT03580369 (PEARL-1) and NCT03580356 (PEARL-2). Both trials are now complete. FINDINGS: Between Oct 17, 2018, and Oct 26, 2021, 2057 adult patients were randomly allocated across both studies (72 mg ligelizumab n=614; 120 mg ligelizumab n=616; 300 mg omalizumab n=618, and placebo n=209). A total of 1480 (72%) of 2057 were female, and 577 (28%) of 2057 were male. Mean UAS7 at baseline across study groups ranged from 29·37 to 31·10. At week 12, estimated treatment differences in mean CFB-UAS7 were as follows: for 72 mg ligelizumab versus placebo, -8·0 (95% CI -10·6 to -5·4; PEARL-1), -10·0 (-12·6 to -7·4; PEARL-2); 72 mg ligelizumab versus omalizumab 0·7 (-1·2 to 2·5; PEARL-1), 0·4 (-1·4 to 2·2; PEARL-2); 120 mg ligelizumab versus placebo -8·0 (-10·5 to -5·4; PEARL-1), -11·1 (-13·7 to -8·5; PEARL-2); 120 mg ligelizumab versus omalizumab 0·7 (-1·1 to 2·5; PEARL-1), -0·7 (-2·5 to 1·1; PEARL-2). Both doses of ligelizumab were superior to placebo (p<0·0001), but not to omalizumab, in both studies. No new safety signals were identified for ligelizumab or omalizumab. INTERPRETATION: In the phase 3 PEARL studies, ligelizumab demonstrated superior efficacy versus placebo but not versus omalizumab. The safety profile of ligelizumab was consistent with previous studies. FUNDING: Novartis Pharma.

Ligelizumab for Chronic Spontaneous Urticaria.

BACKGROUND: In the majority of patients with chronic spontaneous urticaria, most currently available therapies do not result in complete symptom control. Ligelizumab is a next-generation high-affinity humanized monoclonal anti-IgE antibody. Data are limited regarding the dose-response relationship of ligelizumab and the efficacy and safety of ligelizumab as compared with omalizumab and placebo in patients who have moderate-to-severe chronic spontaneous urticaria that is inadequately controlled with H1-antihistamines at approved or increased doses, alone or in combination with H2-antihistamines or leukotriene-receptor antagonists. METHODS: In a phase 2b dose-finding trial, we randomly assigned patients to receive ligelizumab at a dose of 24 mg, 72 mg, or 240 mg, omalizumab at a dose of 300 mg, or placebo, administered subcutaneously every 4 weeks for a period of 20 weeks, or a single 120-mg dose of ligelizumab. Disease symptoms of hives, itch, and angioedema were monitored by means of weekly activity scores. The main objective was to determine a dose-response relationship for the complete control of hives (indicated by a weekly hives-severity score of 0, on a scale from 0 to 21, with higher scores indicating greater severity); the primary end point of this response was assessed at week 12. Complete symptom control was indicated by a weekly urticaria activity score of 0 (on a scale from 0 to 42, with higher scores indicating greater severity). Safety was analyzed throughout the trial. RESULTS: A total of 382 patients underwent randomization. At week 12, a total of 30%, 51%, and 42% of the patients treated with 24 mg, 72 mg, and 240 mg, respectively, of ligelizumab had complete control of hives, as compared with 26% of the patients in the omalizumab group and no patients in the placebo group. A dose-response relationship was established. At week 12, a total of 30%, 44%, and 40% of the patients treated with 24 mg, 72 mg, and 240 mg, respectively, of ligelizumab had complete control of symptoms, as compared with 26% of the patients in the omalizumab group and no patients in the placebo group. In this small and short trial, no safety concerns regarding ligelizumab or omalizumab emerged. CONCLUSIONS: A higher percentage of patients had complete control of symptoms of chronic spontaneous urticaria with ligelizumab therapy of 72 mg or 240 mg than with omalizumab or placebo. (Funded by Novartis Pharma; ClinicalTrials.gov number, NCT02477332.).

Sustained safety and efficacy of ligelizumab in patients with chronic spontaneous urticaria: A one-year extension study.

BACKGROUND: Ligelizumab, a next-generation, humanized anti-immunoglobulin E (IgE) monoclonal antibody is in development as a treatment for patients with chronic spontaneous urticaria, whose symptoms are inadequately controlled with standard-of-care therapy. OBJECTIVE: To evaluate the long-term safety and re-treatment efficacy of ligelizumab 240 mg in patients who completed the core study and extension study. METHODS: This open-label, single-arm, long-term Phase 2b extension study was designed to assess patients who were previously administered various doses of ligelizumab, omalizumab or placebo in the Phase 2b, dose-finding core study and who presented with active disease after Week 32. In the extension study, patients received ligelizumab 240 mg subcutaneously every 4 weeks, for 52 weeks and were monitored post-treatment for 48 weeks. RESULTS: Overall, ligelizumab was well-tolerated with no newly identified safety signals. A total of 95.4% (226/237) screened patients received ligelizumab 240 mg in the extension study; 84.1% (190/226) of patients experienced at least one treatment-emergent adverse event. Most reported events were mild (41.6%) or moderate (35.8%) and mostly unrelated to the study treatment. At Week 12, 46.5% of patients had a complete response increasing to 53.1% after 52 weeks. Following 52 weeks of extension study treatment, 75.8% (95% confidence interval, 69.9, 81.3) of patients had cumulative complete responses. The median time to relapse in complete responders was 38 weeks. CONCLUSION: The long-term safety profile of ligelizumab 240 mg in patients with chronic spontaneous urticaria was consistent with the core study and re-treatment efficacy was shown. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02477332 and NCT02649218.

Fevipiprant has a low risk of influencing co-medication pharmacokinetics: Impact on simvastatin and rosuvastatin in different SLCO1B1 genotypes.

Fevipiprant, a prostaglandin D2 receptor 2 antagonist, is in clinical development as a treatment for asthma. The goal of this study was to assess the potential of fevipiprant to cause drug-drug interactions (DDI) as a perpetrator, that is, by altering the pharmacokinetics (PK) of co-medications. In vitro drug interaction studies of clinically relevant drug metabolizing enzymes and transporters were conducted for fevipiprant and its acyl glucuronide (AG) metabolite. Comparison of Ki values with unbound systemic or portal vein steady-state plasma exposure of fevipiprant and its AG metabolite revealed the potential for inhibition of organic anion transporting polypeptide 1B1 (OATP1B1) transporters (R-value of 5.99), while other targets including cytochrome P450 enzymes were not, or only marginally, inhibited. Consequently, an open-label, two-part, two-period, single-sequence clinical study assessed the effect of fevipiprant 450 mg QD on the pharmacokinetics of simvastatin 20 mg and rosuvastatin 20 mg, two statins with different dependency in OATP1B1-mediated hepatic uptake, in healthy adult volunteers. The study also assessed the pharmacogenetics of the SLCO1B1 gene, which encodes OATP1B1. Clinically, fevipiprant 450 mg QD showed a low potential for interaction and increased the peak concentrations of simvastatin acid and rosuvastatin by 2.23- and 1.87-fold, respectively, with little or no impact on total exposure. Genotype analysis confirmed that SLCO1B1 genotype influences statin pharmacokinetics to a similar extent either with or without fevipiprant co-administration. In summary, fevipiprant at 450 mg QD has only minor liabilities as a perpetrator for DDI.

Ligelizumab improves angioedema, disease severity and quality-of-life in patients with chronic spontaneous urticaria.

Background: Disease burden is particularly high in Chronic Spontaneous Urticaria (CSU) patients with angioedema, and patients whose signs and symptoms are inadequately controlled by H1-antihistamines need new treatment options. Here we report an exploratory analysis, from the ligelizumab Phase 2b study, investigating angioedema occurrence in patients with CSU and describe the changes in angioedema following treatment with ligelizumab, omalizumab, or placebo. Methods: Data from the ligelizumab Phase 2b core (ligelizumab 72 mg, 240 mg, omalizumab 300 mg and placebo) and extension study (ligelizumab 240 mg) were used. Changes in Weekly Angioedema Activity Score (AAS7), the Dermatology Life Quality Index (DLQI), and Weekly Urticaria Activity Score (UAS7) among each time point were analyzed for each treatment arm. Results: From a total of 297 patients analyzed, 165 (55.6%) reported angioedema occurrence at baseline, with mean AAS7 ranging 30.6-42.2 across treatment arms. At Week 12 of the core study 87.5%, 84.6%, 75.0%, and 61.0% of patients were angioedema free for ligelizumab 72 mg, 240 mg, omalizumab 300 mg, and placebo arms, respectively. In CSU patients with angioedema at baseline, the largest change from baseline in AAS7 score was observed with ligelizumab 72 mg (-31.9) at week 16 in the core study. Patients with angioedema had a higher mean DLQI at baseline (14.9-16.1) vs. patients without angioedema (10.6-12.0). In patients with angioedema, low AAS7 was significantly associated with complete response on UAS7 (UAS7 = 0) and complete normalization of DLQI (DLQI 0-1). Conclusion: In the Phase 2b study, ligelizumab effectively reduced angioedema and urticaria symptoms, and improve health related quality of life in patients with moderate-to-severe CSU. Clinicaltrailsgov NCT number: NCT02477332; NCT02649218.

Mixed tocotrienols inhibit prostate carcinogenesis in TRAMP mice.

The biological activities of tocotrienols are receiving increasing attention. Herein, we report the efficacy of a mixed-tocotrienol diet against prostate tumorigenesis in the transgenic adenocarcinoma mouse prostate (TRAMP) mouse model. Male TRAMP mice, 8 wk old, were fed 0.1%, 0.3%, or 1% mixed tocotrienols in AIN-76A diet up to 24 wk old. Likewise, a positive control group consisting of male TRAMP mice and a negative control group consisting of wild-type nontransgenic mice were fed regular AIN-76A diet up to 24 wk old. Our results show that mixed-tocotrienol-fed groups had a lower incidence of tumor formation along with a significant reduction in the average wet weight of genitourinary apparatus. Furthermore, mixed tocotrienols significantly reduced the levels of high-grade neoplastic lesions as compared to the positive controls. This decrease in levels of high-grade neoplastic lesions was found to be associated with increased expression of proapoptotic proteins BAD (Bcl(2) antagonist of cell death) and cleaved caspase-3 and cell cycle regulatory proteins cyclin dependent kinase inhibitors p21 and p27. In contrast, the expression of cyclins A and E were found to be decreased in mixed-tocotrienol groups. Taken together, our results show that by modulating cell cycle regulatory proteins and increasing expression of proapoptotic proteins, mixed tocotrienols suppress prostate tumorigenesis in the TRAMP mice.

Regulation of Nrf2- and AP-1-mediated gene expression by epigallocatechin-3-gallate and sulforaphane in prostate of Nrf2-knockout or C57BL/6J mice and PC-3 AP-1 human prostate cancer cells.

AIM: To examine the regulatory crosstalk between the transcription factors Nrf2 and AP-1 in prostate cancer (PCa) by dietary cancer chemopreventive compounds (-)epigallocatechin-3-gallate (EGCG) from green tea and sulforaphane (SFN) from cruciferous vegetables. METHODS: We performed (i) in vitro studies including luciferase reporter gene assays, MTS cell viability assays, and quantitative real-time PCR (qRT-PCR) in PC-3 AP-1 human PCa cells, (ii) in vivo temporal (3 h and 12 h) microarray studies in the prostate of Nrf2-deficient mice that was validated by qRT-PCR, and (iii) in silico bioinformatic analyses to delineate conserved Transcription Factor Binding Sites (TFBS) in the promoter regions of Nrf2 and AP-1, as well as coregulated genes including ATF-2 and ELK-1. RESULTS: Our study shows that AP-1 activation was attenuated by the combinations of SFN (25 micromol/L) and EGCG (20 or 100 micromol/L) in PC-3 cells. Several key Nrf2-dependent genes were down-regulated (3-fold to 35-fold) after in vivo administration of the combination of EGCG (100 mg/kg) and SFN (45 mg/kg). Conserved TFBS signatures were identified in the promoter regions of Nrf2, AP-1, ATF2, and ELK-1 suggesting a potential regulatory mechanism of crosstalk between them. CONCLUSION: Taken together, our present study of transcriptome profiling the gene expression changes induced by dietary phytochemicals SFN and EGCG in Nrf2-deficient mice and in PC-3 cells in vitro demonstrates that the effects of SFN+EGCG could be mediated via concerted modulation of Nrf2 and AP-1 pathways in the prostate.

Drug-Drug Interaction Studies With Oral Contraceptives: Pharmacokinetic/Pharmacodynamic and Study Design Considerations.

Oral contraceptives (OCs) are the most widely used form of birth control among women of childbearing potential. Knowledge of potential drug-drug interactions (DDIs) with OCs becomes imperative to provide information on the medication to women of childbearing potential and enable their inclusion in clinical trials, especially if the new molecular entity is a teratogen. Although a number of DDI guidance documents are available, they do not provide recommendations for the design and conduct of OC DDI studies. The evaluation of DDI potential of a new molecular entity and OCs is particularly challenging because of the availability of a wide variety of combinations of hormonal contraceptives, different doses of the ethinyl estradiol, and different metabolic profiles of the progestin component. The aim of this review is to comprehensively discuss factors to be considered such as pharmacokinetics (PK), pharmacodynamics (PD), choice of OC, and study population for the conduct of in vivo OC DDI studies. In this context, metabolic pathways of OCs, the effect of enzyme inhibitors and inducers, the role of sex hormone-binding globulin in the PK of progestins, current evidence on OC DDIs, and the interpretation of PD end points are reviewed. With the emergence of new tools like physiologically based PK modeling, the decision to conduct an in vivo study can be made with much more confidence. This review provides a comprehensive overview of various factors that need to be considered in designing OC DDI studies and recommends PK-based DDI studies with PK end points as adequate measures to establish clinical drug interaction and measurement of PD end points when there is basis for PD interaction.

Gamma-tocopherol-enriched mixed tocopherol diet inhibits prostate carcinogenesis in TRAMP mice.

Gamma-tocopherol (gamma-T) alone or in combination with alpha-tocopherol has been shown to suppress biomarkers of oxidative stress in asthamatics and human subjects with metabolic syndrome. Oxidative stress has been implicated as a key event in prostate carcinogenesis. Hence, the purpose of this study was to examine the effects of gamma-tocopherol-enriched mixed tocopherol diet on prostate carcinogenesis in a murine prostate cancer model (TRAMP). 8 week old TRAMP males were fed 0.1% gamma-T-enriched mixed tocopherol diet that contained 20-fold higher levels of gamma-tocopherol, and roughly 3-fold higher levels of alpha-tocopherol. The effect of such diet on tumor and PIN development was observed. The expression of phase II detoxifying, antioxidant enzymes and Nrf2 mRNA and protein were determined by RT-PCR, immunohistochemistry and western blotting techniques. Treatment with gamma-T-enriched mixed tocopherols significantly suppressed the incidence of palpable tumor and Prostate Intraepithelial Neoplasia (PIN) development without affecting the expression of the transgene (SV-40). Tumor progression occurred with a significant suppression of antioxidant enzymes such as catalase, superoxide dismutase, glutathione peroxidase, heme-oxygenase-1 and phase II detoxifying enzymes. Treatment with gamma-T-enriched mixed tocopherol diet upregulated the expression of most detoxifying and antioxidant enzymes. Nrf2-a redox sensitive transcription factor known to mediate the expression of phase II detoxifying enzymes, was also significantly upregulated following treatment with gamma-T-enriched mixed tocopherol diet. Gamma-T-enriched mixed tocopherols significantly up-regulated the expression of Nrf2 and its related detoxifying and antioxidant enzymes thereby suppressing PIN and tumor development.

Pharmacokinetics and pharmacodynamics of broccoli sprouts on the suppression of prostate cancer in transgenic adenocarcinoma of mouse prostate (TRAMP) mice: implication of induction of Nrf2, HO-1 and apoptosis and the suppression of Akt-dependent kinase pathway.

PURPOSE: In the present study, we have evaluated the pharmacokinetics and the in vivo prostate chemopreventive activity of broccoli sprouts. METHODS: The in vivo pharmacokinetic profiles of sulforaphane (SFN) and SFN- glutathione (GSH) conjugate in rats after oral administration of 200 mg and 500 mg broccoli sprouts were analyzed. Next, 8-week old TRAMP mice were fed with dietary broccoli sprouts at two dosages (60 and 240 mg/mouse/day) for 16 weeks, and the mice were sacrificed to examine the pharmacodynamic response on prostate tumor and some biomarkers. RESULTS: SFN was readily released and conjugated with GSH in the rats after oral administration of broccoli sprouts. TRAMP mice fed with 240 mg broccoli sprouts/mouse/day exhibited a significant retardation of prostate tumor growth. Western blot analysis revealed that the expression levels of Nrf2, HO-1, cleaved-Caspase-3, cleaved-PARP and Bax proteins were increased, but that of Keap1 and Bcl-XL proteins were decreased. In addition, the phosphorylation and/or the expression level of Akt and its downstream kinase and target proteins, e.g. mTOR, 4E-BP1 and cyclin D1, were reduced. CONCLUSIONS: Our findings indicate that broccoli sprouts can serve as a good dietary source of SFN in vivo and that they have significant inhibitory effects on prostate tumorigenesis.

Metabolism, oral bioavailability and pharmacokinetics of chemopreventive kaempferol in rats.

The purpose of this study was to compare the hepatic and small intestinal metabolism, and to examine bioavailability and gastro-intestinal first-pass effects, of kaempferol in rats. Liver and small intestinal microsomes fortified with either NADPH or UDPGA were incubated with varying concentrations of kaempferol for up to 120 min. Based on the values of the kinetic constants (K(m) and V(max)), the propensity for UDPGA-dependent conjugation compared with NADPH-dependent oxidative metabolism was higher for both hepatic and small intestinal microsomes. Male Sprague-Dawley rats were administered kaempferol intravenously (i.v.) (10, 25 mg/kg) or orally (100, 250 mg/kg). Gastro-intestinal first-pass effects were observed by collecting portal blood after oral administration of 100 mg/kg kaempferol. Pharmacokinetic parameters were obtained by non-compartmental analysis using WinNonlin. After i.v. administration, the plasma concentration-time profiles for 10 and 25 mg/kg were consistent with high clearance (approximately 3 L/hr/kg) and large volumes of distribution (8-12 L/hr/kg). The disposition was characterized by a terminal half-life value of 3-4 h. After oral administration the plasma concentration-time profiles demonstrated fairly rapid absorption (t(max) approximately 1-2 h). The area under the curve (AUC) values after i.v. and oral doses increased approximately proportional to the dose. The bioavailability (F) was poor at approximately 2%. Analysis of portal plasma after oral administration revealed low to moderate absorption. Taken together, the low F of kaempferol is attributed in part to extensive first-pass metabolism by glucuronidation and other metabolic pathways in the gut and in the liver.

A first-in-human, randomized, double-blind, placebo-controlled, single and multiple ascending oral dose study to assess the safety, tolerability, and pharmacokinetics of BZF961 with and without ritonavir in healthy adult volunteers.

Objective: Infection with hepatitis C virus is the leading indication for liver transplantation and most common cause of infectious disease-related mortality in the United States. BZF961 is a novel inhibitor of the hepatitis C virus NS3-4A protease. Methods: This sequential, three part exploratory first-in-human study investigated the safety and pharmacokinetics of single and multiple ascending oral doses of BZF961 in healthy subjects. The first two parts were randomized, double-blind, placebo-controlled, time-lagged, single and multiple ascending oral dose segments. The third part analyzed the effect of ritonavir on BZF961 pharmacokinetics. Results: BZF961 was generally safe and well-tolerated in single and multiple oral doses in healthy subjects. There were no deaths and no serious adverse events. The most common adverse events were nausea and other gastrointestinal symptoms. Co-administration of ritonavir with BZF961 was well tolerated and increased BZF961 exposure by up to 60-fold, as well as reduced the overall exposure variability. Conclusions: BZF961 was generally safe and well-tolerated and its exposure was boosted by the co-administration of ritonavir.

The Safety and Antiviral Activity of BZF961 with or without Ritonavir in Patients Infected with Hepatitis C Virus: A Randomized, Multicenter Trial.

PURPOSE: Infection with hepatitis C virus is the leading cause of infectious disease mortality in the United States. BZF961 is a novel small molecule inhibitor of the hepatitis C virus NS3-4A protease. Here we present the results of a randomized, double-blinded, placebo-controlled, multicentered study in treatment-naïve patients with chronic hepatitis C virus genotype-1 infection. METHODS: Patients were enrolled sequentially in 2 parts and treated for 3days. BZF961 was administered as monotherapy (500mg BID for 3 days) or in combination with the cytochrome P450 3A4 inhibitor ritonavir to boost its exposure (BZF961 10, 20, or 50mg QD or BID). FINDINGS: BZF961 was safe and well tolerated in the patients studied with no serious adverse events. There were no appreciable differences in adverse events among patients who received BZF961, BZF961 with ritonavir, or placebo. There was a significant, clinically meaningful reduction in viral load from baseline in patients treated either with BZF961 500mg every 12hours alone or BZF961 50mg every 12hours in combination with ritonavir. Activity against the hepatitis C virus of the lower-dose regimens was apparent but more modest. There were no relevant changes from baseline viral loads in placebo-treated patients. IMPLICATIONS: Coadministration of ritonavir with BZF961 boosted BZF961 exposure (including Cmin, which is the clinically relevant parameter associated with antiviral activity) in a therapeutic range with less variability compared with BZF961 alone. For strategic reasons, BZF961 is no longer under development.

Clinical Exposure Boost Predictions by Integrating Cytochrome P450 3A4-Humanized Mouse Studies With PBPK Modeling.

NVS123 is a poorly water-soluble protease 56 inhibitor in clinical development. Data from in vitro hepatocyte studies suggested that NVS123 is mainly metabolized by CYP3A4. As a consequence of limited solubility, NVS123 therapeutic plasma exposures could not be achieved even with high doses and optimized formulations. One approach to overcome NVS123 developability issues was to increase plasma exposure by coadministrating it with an inhibitor of CYP3A4 such as ritonavir. A clinical boost effect was predicted by using physiologically based pharmacokinetic (PBPK) modeling. However, initial boost predictions lacked sufficient confidence because a key parameter, fraction of drug metabolized by CYP3A4 (fmCYP3A4), could not be estimated with accuracy on account of disconnects between in vitro and in vivo preclinical data. To accurately estimate fmCYP3A4 in human, an in vivo boost effect study was conducted using CYP3A4-humanized mouse model which showed a 33- to 56-fold exposure boost effect. Using a top-down approach, human fmCYP3A4 for NVS123 was estimated to be very high and included in the human PBPK modeling to support subsequent clinical study design. The combined use of the in vivo boost study in CYP3A4-humanized mouse model mice along with PBPK modeling accurately predicted the clinical outcome and identified a significant NVS123 exposure boost (∼42-fold increase) with ritonavir.

The effects of CYP3A4 induction and inhibition on the pharmacokinetics of alisporivir in humans.

In vitro data suggest that alisporivir is a substrate and inhibitor of CYP3A4 and P-gp. Hence, the potential for drug-drug interactions when alisporivir is co-administered with CYP3A4 and/or P-gp inhibitors such as ketoconazole, azithromycin and CYP3A4 inducers such as rifampin were evaluated in three separate clinical studies. Co-administration with ketoconazole (a strong CYP3A4 inhibitor) increased the Cmax , AUC and terminal elimination half-life of alisporivir by approximately two-, eight- ,and threefold, respectively. Co-administration with azithromycin (a putative weak CYP3A4 inhibitor and substrate) had no impact on the Cmax and AUC of alisporivir. Rifampin (a CYP3A4 inducer) caused an approximate 90% reduction in alisporivir Cmax and AUC and a fourfold reduction in alisporivir terminal elimination half-life. Alisporivir as an inhibitor of CYP3A4 caused a 39% increase in azithromycin exposure. The results from these studies establish alisporivir as a sensitive CYP3A4 substrate in vivo. Consequently, co-administered potent CYP3A4 inhibitors and inducers are likely to cause clinically significant changes in the exposure to alisporivir.

Physiologically based pharmacokinetic modeling for assessing the clinical drug-drug interaction of alisporivir.

Alisporivir is a novel cyclophilin-binding molecule with potent anti-hepatitis C virus (HCV) activity. In vitro data from human liver microsomes suggest that alisporivir is a substrate and a time-dependent inhibitor (TDI) of CYP3A4. The aim of the current work was to develop a novel physiologically based pharmacokinetic (PBPK) model to quantitatively assess the magnitude of CYP3A4 mediated drug-drug interactions with alisporivir as the substrate or victim drug. Towards that, a Simcyp PBPK model was developed by integrating in vitro data with in vivo clinical findings to characterize the clinical pharmacokinetics of alisporivir and further assess the magnitude of drug-drug interactions. Incorporated with absorption, distribution, elimination, and TDI data, the model accurately predicted AUC, Cmax, and tmax values after single or multiple doses of alisporivir with a prediction deviation within ± 32%. The model predicted an alisporivir AUC increase by 9.4-fold and a decrease by 86% when alisporivir was co-administrated with ketoconazole (CYP3A4 inhibitor) or rifampin (CYP3A4 inducer), respectively. Predictions were within ± 20% of the observed changes. In conclusion, the PBPK model successfully predicted the alisporivir PK and the magnitude of drug-drug interactions.

Pharmacogenomic profile of soy isoflavone concentrate in the prostate of Nrf2 deficient and wild-type mice.

The involvement of Nrf2-a bZip transcription factor in soy isoflavones induced protection against oxidative stress and cancer has been reported. To gain better insight into the role of Nrf2 in prostate cancer chemoprevention by soy isoflavones, we examined the pharmacogenomics and gene expression profiles elicited by soy isoflavones in the prostates of C57BL/6J/Nrf2(-/-) and C57BL6J/Nrf2(+/+) wildtype. The profiles were analyzed using 45000 Affymetrix mouse genome 430-2.0 array and Genespring-7.2 software. The results obtained from microarray were further validated by real-time reverse transcription-PCR. Clusters of genes that were induced or suppressed more than twofold were identified as Nrf2 regulated soy isoflavone induced or suppressed genes. Classification based on their biological function revealed that genes mainly belonging to the categories of electron transport, phase II metabolizing enzymes, cell growth and differentiation, apoptosis, cell cycle, transcription factors, transport, mRNA processing, and carbohydrate homeostasis were either induced or suppressed by soy isoflavone and regulated by Nrf2. In addition, modulation of novel target genes such as LATS2 and GREB1 were identified to be mediated by Nrf2. Thus our current study provides a potential link between cancer chemopreventive properties of soy derived phytochemicals, the transcription factor Nrf2 and prevention of prostate cancer.

Murine prostate cancer inhibition by dietary phytochemicals--curcumin and phenyethylisothiocyanate.

PURPOSE: Prior studies from our laboratory have demonstrated the efficacy of a combined treatment of low doses of dietary agents curcumin and phenylethylisothiocyanate in effectively suppressing prostate cancer in vitro in human prostate cancer PC3 cells as well as in vivo in immunodeficient mice implanted with PC3 cells. Hence, this study was undertaken to examine the potential chemopreventive properties of the two agents against transgenic adenocarcinoma of the mouse prostate. MATERIALS AND METHODS: The efficacy of AIN-76A diet supplemented with 2% curcumin or 0.05% PEITC or a combination of 1% curcumin and 0.025% PEITC for periods of 10 and 16 weeks was tested against adenocarcinoma of the mouse prostate. Immunohistochemistry and Western blot analysis were used to examine the expression of proliferation and apoptotic biomarkers. All statistical tests were two-sided. RESULTS: Supplementing AIN-76A diet with dietary phytochemicals curcumin or PEITC either alone or in combination, significantly decreased incidence of prostate tumor formation (P = 0.0064). Immunohistochemistry revealed a significant inhibition of high-grade PIN (P = 0.0006, 0.000069, 0.00029 for a treatment period of 10 weeks and P = 0.02582, 0.022179, 0.0317 for a treatment period of 16 weeks) along with decreased proliferation and increased apoptotic index in the curcumin, PEITC or curcumin and PEITC treated animals, respectively. Furthermore, Western blot analysis revealed that downregulation of the Akt signaling pathway may in part play a role in decreasing cell proliferation ultimately retarding prostate tumor formation. CONCLUSION: Our data lucidly evidence the chemopreventive merits of dietary phytochemicals curcumin and PEITC in suppressing prostate adenocarcinoma.

Cancer chemoprevention by phytochemicals: potential molecular targets, biomarkers and animal models.

Recent studies have strongly indicated that certain daily-consumed dietary phytochemicals could have cancer protective effects against transgenic mice cancer models and cancers mediated by carcinogens, irradiations and carcinogenic metabolites derived from exogenous or endogenous sources. The cancer-protective effects elicited by these dietary compounds are believed to be due at least in part to the induction of cellular defense systems including the detoxifying and antioxidant enzymes system, as well as the inhibition of anti-inflammatory and anti-cell growth signaling pathways culminating in cell cycle arrest and/or celldeath. In this review, we summarize the potential mechanisms including the modulation of nuclear factor kappaB (NF-kappaB), cyclooxygenases-2 (COX-2), activator protein-1 (AP-1), mitogen-activated protein kinases (MAPKs) and the induction of phase II cellular detoxifying and antioxidant enzymes mediated mainly by the antioxidant response elements (ARE) within the promoter regions of these genes through nuclear factor-erythroid 2-related factor 2 (Nrf2), a member of the Cap "n" collar (CNC) family of the basic region-leucine zipper transcription factor. In addition, we also review several animal models of carcinogenesis and cancer chemopreventive efficacy studies of these animal models using dietary chemopreventive compounds. Finally, we discuss the cellular signaling cascades mediated by Nrf2, NF-kappaB, AP-1, MAPKs and COX-2, which have been considered to play pivotal roles in tumor initiation, promotion and progression processes, and could be promising molecular targets for the design of drugs targeting cancer prevention and therapy.