A phase Ib study of the VEGF receptor tyrosine kinase inhibitor tivozanib and modified FOLFOX-6 in patients with advanced gastrointestinal malignancies.

BACKGROUND: Tivozanib hydrochloride (tivozanib) is a potent and selective tyrosine kinase inhibitor of all 3 vascular endothelial growth factor receptors with antitumor activity additive to 5-fluorouracil in preclinical models. This study was conducted to determine maximum tolerated dose (MTD), dose-limiting toxicities (DLTs), pharmacokinetics (PKs), and antitumor activity of escalating doses of tivozanib with a modified (m)FOLFOX-6 (leucovorin, 5-fluorouracil [5-FU], and 85 mg/kg(2) oxaliplatin) regimen in patients with advanced gastrointestinal tumors. PATIENTS AND METHODS: Tivozanib was administered orally once daily for 21 days in 28-day cycles, with mFOLFOX-6 administered every 14 days. Patients were allowed to continue tivozanib after discontinuation of mFOLFOX-6. RESULTS: Thirty patients were assigned to tivozanib 0.5 mg (n = 9), 1.0 mg (n = 3), or 1.5 mg (n = 18) with mFOLFOX-6. Patients received a median of 5.2 (range, 0.03-26.9) months of tivozanib. DLTs were observed in 2 patients: Grade 3/4 transaminase level increases with tivozanib 0.5 mg, and Grade 3 dizziness with tivozanib 1.5 mg. Other Grade 3/4 adverse events included hypertension (n = 8), fatigue (n = 8), and neutropenia (n = 6). MTD for tivozanib with mFOLFOX-6 was confirmed as 1.5 mg. No PK interactions between tivozanib and mFOLFOX-6 were observed. One patient had an ongoing clinical complete response, 10 had a partial response, and 11 obtained prolonged stable disease. CONCLUSION: Tivozanib and mFOLFOX-6 is feasible and appears to be safe. The recommended dose for tivozanib with mFOLFOX-6 is 1.5 mg/d. Observed clinical activity merits further exploration in gastrointestinal tumors.

Effects of ketoconazole or rifampin on the pharmacokinetics of tivozanib hydrochloride, a vascular endothelial growth factor receptor tyrosine kinase inhibitor.

The vascular endothelial growth factor (VEGF) pathway is associated with the promotion of endothelial cell proliferation, migration, and survival necessary for angiogenesis. VEGF and its three receptor isoforms are often overexpressed in many human solid tumors. Tivozanib is a potent, selective inhibitor of VEGF receptors 1, 2, and 3, with a long half-life. The purpose of these studies was to evaluate the effect of ketoconazole, a potent inhibitor of CYP3A4, and rifampin, a potent inducer of CYP3A4, on the pharmacokinetics of tivozanib. Two phase I, open-label, 2-period, single-sequence studies evaluated the effect of steady-state ketoconazole (NCT01363778) or rifampin (NCT01363804) on the pharmacokinetic profile, safety, and tolerability of a single oral 1.5-mg dose of tivozanib. Tivozanib was well tolerated in both studies. Steady-state ketoconazole did not cause a clinically significant change in the pharmacokinetics of a single dose of tivozanib; therefore, dosing of tivozanib with a CYP3A4 pathway inhibitor should not cause a clinically significant change in serum tivozanib levels. However, coadministration of tivozanib with rifampin caused a significant decrease in the area under the curve from 0 to infinity and half-life and an increase in clearance of tivozanib, which suggest increased clearance via the enhanced CYP3A4-mediated metabolism of tivozanib.

The effect of food on the pharmacokinetics of tivozanib hydrochloride.

Tivozanib hydrochloride (tivozanib) is a potent, selective tyrosine kinase inhibitor of the vascular endothelial growth factor receptors 1, 2, and 3, with a long half-life. This Phase I study evaluated the effect of food on tivozanib pharmacokinetics (PK). A single oral dose of tivozanib was administered to healthy subjects in a fasted/fed and a fed/fasted state. Thirty subjects enrolled; 29 completed the study. Maximum concentration (Cmax ) in the fed state was lower than in the fasted state (geometric means, 14.1 and 18.1 ng/mL). The geometric mean ratio (90% confidence interval) (fed/fasted states) for Cmax was 77.5% (72.9-82.4%), indicating a food effect on Cmax . There was no difference in tivozanib area under the curve to infinity (AUC0-∞ ) between states (geometric means, 2,377 and 2,198 ng h/mL). Geometric mean ratios also indicated no food effect on tivozanib AUC0-∞ . Other PK parameters were similar between states. The most commonly reported adverse events affected the gastrointestinal system and were mild in intensity. There were no clinically significant changes in other safety measures. In conclusion, food does not have an impact on the AUC0-∞ of tivozanib but does decrease Cmax approximately 23%, suggesting that this agent can be dosed with or without food.

A Phase I cardiac safety and pharmacokinetic study of tivozanib hydrochloride in patients with advanced solid tumors.

Tivozanib hydrochloride (tivozanib) is a potent, selective tyrosine kinase inhibitor of all three vascular endothelial growth factor receptors, with a long half-life. Tivozanib's effects on the QTc interval in patients with advanced solid tumors were assessed. Patients received 1.5 mg of tivozanib orally, once daily, for 21 days. Safety evaluations, serial blood samples for pharmacokinetic measurements, and time-matched, triplicate, 12-lead electrocardiograms (ECG) were collected. Fifty patients were evaluable. The maximum change in QTcF was 9.3 milliseconds (90% confidence interval [CI] 5-13.6), occurring 2.5 hours after dosing on Day 21. The central tendency change across all time points was +2.2 milliseconds. The slope of the exposure-ΔQTcF relationship was 0.08464 ms/ng/mL, with a predicted QTcF change of 8.27 milliseconds at the average tivozanib Tmax of 118.1 ng/mL (upper CI 12.6 milliseconds). There were no QTcF values >500 milliseconds or significant changes from baseline observed in heart rate, PR interval, and QRS complex. These data, evaluated along with other tivozanib preclinical and clinical study results, suggest that administration of 1.5 mg tivozanib for 21 days has a minimal effect on cardiac repolarization or ECG morphology in oncology subjects.

Absorption, Metabolism, and Excretion of [(14) C]-Tivozanib, a Vascular Endothelial Growth Factor Receptor Tyrosine Kinase Inhibitor, in Healthy Male Participants: A Phase I, Open-Label, Mass-Balance Study.

OBJECTIVE: To evaluate the absorption, metabolism, and excretion of tivozanib, a new investigational drug for renal cell carcinoma and solid malignancies. METHODS: Eight healthy male participants received a single 1.5-mg (˜160 µCi) dose of oral [(14) C]-tivozanib. Whole blood, serum, urine, and feces were evaluated up to 28 days postdose for pharmacokinetics, radioanalysis, and metabolites. Adverse events were recorded throughout the study. RESULTS: [(14) C]-tivozanib concentration peaked at 10.9 ± 5.84 hours. The mean serum half-life for [(14) C]-tivozanib was 89.3 ± 23.5 hours. The maximum concentration and area under the curve for [(14) C]-tivozanib were 12.1 ± 5.67 ng/mL and 1084 ± 417.0 ng·h/mL, respectively. Mean recovery of total radioactivity was 91.0% ± 11.0%; 79.3% ± 8.82% of the radioactivity was recovered in feces both as unchanged tivozanib and metabolites. In the urine, 11.8% ± 4.59% was recovered only as metabolites. No unchanged tivozanib was found in the urine. CONCLUSION: Tivozanib had a long half-life with no major circulating metabolite, was well tolerated as a single dose, and was primarily eliminated via feces with no unchanged tivozanib found in urine. These pharmacokinetic data of [(14) C]-tivozanib are consistent with previous studies of unlabeled tivozanib.

Biologic and clinical activity of tivozanib (AV-951, KRN-951), a selective inhibitor of VEGF receptor-1, -2, and -3 tyrosine kinases, in a 4-week-on, 2-week-off schedule in patients with advanced solid tumors.

PURPOSE: To assess the maximum tolerated dose (MTD)/dose-limiting toxicities (DLT), safety, pharmacokinetics, and pharmacodynamics of tivozanib, a potent and selective oral VEGF receptor (VEGFR) tyrosine kinase inhibitor. EXPERIMENTAL DESIGN: Dose levels of 1.0, 1.5, and 2.0 mg/d tivozanib for 28 days followed by 14 days of medication were explored in patients with advanced solid tumors. RESULTS: Forty-one patients were enrolled. Animal data incorrectly predicted toxicity, resulting in DLTs at the starting dose (2.0 mg) consisting of grade 3 proteinuria and hypertension and grade 3 ataxia. At 1.0 mg, no DLT was observed. At an intermediate dose (1.5 mg), 1 patient experienced DLT consisting of grade 3 hypertension. This dose was determined as the MTD. Of 10 additional patients treated at 1.5 mg, 1 patient each experienced grade 3 hypertension and grade 3 fatigue, and 2 patients experienced grade 3 and 4 transaminase elevation. In 12 additional patients treated at 1.0 mg, no DLT was observed. Pharmacokinetics displayed long absorption time, dose proportional exposure, and a half-life of 4.7 days. Plasma levels of VEGF-A and soluble VEGFR-2 showed dose-dependent increases and decreases, respectively. Dynamic contrast-enhanced MRI indicated reduction in tumor perfusion. Clinical activity was observed in renal cell cancer, colorectal cancer, and other tumors. CONCLUSION: Tivozanib was well tolerated with manageable side effects. The pharmacokinetics profile revealed that tivozanib was suitable for once-daily dosing. Encouraging and durable clinical activity was observed. The recommended daily dose of tivozanib in a 4-week-on and 2-week-off dosing regimen is 1.5 mg.

Comparison of human and rat uterine leiomyomata: identification of a dysregulated mammalian target of rapamycin pathway.

Uterine leiomyomata, or fibroids, are benign tumors of the uterine myometrium that significantly affect up to 30% of reproductive-age women. Despite being the primary cause of hysterectomy in the United States, accounting for up to 200,000 procedures annually, the etiology of leiomyoma remains largely unknown. As a basis for understanding leiomyoma pathogenesis and identifying targets for pharmacotherapy, we conducted transcriptional profiling of leiomyoma and unaffected myometrium from humans and Eker rats, the best characterized preclinical model of leiomyomata. A global comparison of mRNA from leiomyoma versus myometrium in human and rat identified a highly significant overlap of dysregulated gene expression in leiomyomata. An unbiased pathway analysis using a method of gene-set enrichment based on the sigPathway algorithm detected the mammalian target of rapamycin (mTOR) pathway as one of the most highly up-regulated pathways in both human and rat tumors. To validate this pathway as a therapeutic target for uterine leiomyomata, preclinical studies were conducted in Eker rats. These rats develop uterine leiomyomata as a consequence of loss of Tsc2 function and up-regulation of mTOR signaling. Inhibition of mTOR in female Eker rats with the rapamycin analogue WAY-129327 for 2 weeks decreased mTOR signaling and cell proliferation in tumors, and treatment for 4 months significantly decreased tumor incidence, multiplicity, and size. These results identify dysregulated mTOR signaling as a component of leiomyoma etiology across species and directly show the dependence of uterine leiomyomata with activated mTOR on this signaling pathway for growth.

A study of 17beta-estradiol-regulated genes in the vagina of postmenopausal women with vaginal atrophy.

BACKGROUND: Vaginal atrophy (VA) is a prevalent disorder in postmenopausal women that is characterized by decreased epithelial thickness, reduced vaginal maturation index (VMI) and increased vaginal pH. Current medical therapy consists of local or systemic replacement of estrogens. OBJECTIVE: The goal of this study was to understand, at a molecular level, the effect of estradiol (E2) on the vaginal epithelium. METHODS: Nineteen women were treated with E2 delivered through a skin patch at a dose of 0.05mg/day for 12 weeks. The diagnosis of VA was confirmed by a VMI with < or =5% superficial cells and vaginal pH>5.0. Vaginal biopsy samples were collected at baseline and after treatment. Differentially expressed mRNA transcripts in these biopsies were determined by microarray analysis. RESULTS: All 19 subjects had increased VMI (>5%) and/or reduced pH (< or =5) following treatment. Most subjects also had increased serum E2 levels and reduced serum FSH levels. Transcriptional profiling of vaginal biopsies identified over 3000 E2-regulated genes, including those involved in several key pathways known to regulate cell growth and proliferation, barrier function and pathogen defense. CONCLUSIONS: E2 controls a plethora of cellular pathways that are concordant with its profound effect on vaginal physiology. The data presented here are a useful step toward understanding the role of E2 in vaginal tissue and the development of novel therapeutics for the treatment of VA.

Molecular classification of Crohn's disease and ulcerative colitis patients using transcriptional profiles in peripheral blood mononuclear cells.

Ulcerative colitis (UC) and Crohn's disease (CD) are common inflammatory bowel diseases producing intestinal inflammation and tissue damage. Although emerging evidence suggests these diseases are distinct, approximately 10% of patients remain classified as indeterminate inflammatory bowel disease even after invasive colonoscopy intended for diagnosis. A molecular diagnostic assay using a clinically accessible tissue would greatly assist in the classification of these diseases. In the present study we assessed transcriptional profiles in peripheral blood mononuclear cells from 42 healthy individuals, 59 CD patients, and 26 UC patients by hybridization to microarrays interrogating more than 22,000 sequences. Supervised analysis identified a set of 12 genes that distinguished UC and CD patient samples with high accuracy. The alterations in transcript levels observed by microarray were verified by real-time polymerase chain reaction. The results suggest that a peripheral blood mononuclear cell-based gene expression signature can provide a molecular biomarker that can complement the standard diagnosis of UC and CD.

A single administration of recombinant human interleukin-12 is associated with increased expression levels of interferon-gamma and signal transducer and activator of transcription in healthy subjects.

The objectives of this study were to assess the safety and tolerability of single doses of 1, 4, and 8 mug of recombinant human interleukin-12 (rhIL-12) administered subcutaneously to healthy subjects. The pharmacokinetics, pharmacodynamics, and pharmacogenomics of rhIL-12 were evaluated. Recombinant human IL-12 was well tolerated in these healthy male and female subjects. The most frequently reported adverse events were flu-like symptoms, which exhibited a dose-response relationship. Pharmacokinetic analysis suggested that serum IL-12 levels increased with dose. Analysis of serum levels indicated that interferon-gamma increased with the dose of rhIL-12, whereas IL-6 levels showed no changes with rhIL-12 treatment. The messenger ribonucleic acid expression of signal transducer and activator of transcription was significantly increased 24 hours after the administration of rhIL-12 for all dose groups versus placebo, and results indicated that the magnitude of increase may be dose dependent. This study suggests that interferon-gamma and signal transducer and activator of transcription are biomarkers of rhIL-12 activity.

Multiple-dose, safety, pharmacokinetics, and pharmacodynamics of a new selective estrogen receptor modulator, ERA-923, in healthy postmenopausal women.

ERA-923 is a new selective estrogen receptor modulator under clinical investigation for use in tamoxifen refractory metastatic breast cancer. This study evaluated the safety, tolerability, pharmacokinetics, and pharmacodynamics of once-daily oral ERA-923 (10-200 mg) for 28 days in healthy postmenopausal females. ERA-923 was well tolerated, and adverse events were mild and reversible. No clinically significant changes in laboratory values were found with ERA-923 versus placebo. ERA-923 appeared to undergo extensive metabolism and enterohepatic recirculation. In addition, pharmacokinetic analysis showed that a high-fat breakfast increased the extent of absorption. ERA-923-dosed subjects had no uterine or ovarian changes when evaluated with transvaginal ultrasound and compared to placebo subjects. Overall, ERA-923 was safe and well tolerated in postmenopausal women dosed for 28 days.