Preeclampsia at delivery is associated with lower serum vitamin D and higher antiangiogenic factors: a case control study.

BACKGROUND: Preeclampsia is characterized by decreased trophoblastic angiogenesis leading to abnormal invasion of spiral arteries, shallow implantation and resulting in compromised placentation with poor uteroplacental perfusion. Vitamin D plays an important role in pregnancy influencing implantation, angiogenesis and placental development. The objective of this study was to determine whether there is an association between serum vitamin D levels, and anti-angiogenic factors at the time of delivery and the occurrence of preeclampsia. METHODS: This nested case control study analyzed frozen serum samples at the time of delivery and related clinical data from women with singleton liveborn pregnancies who had participated in studies of the NICHD Stillbirth Collaborative Research Network. Women with a recorded finding of preeclampsia and who had received magnesium sulfate treatment prior to delivery were considered index cases (N = 56). Women without a finding of preeclampsia were controls (N = 341). RESULTS: Women with preeclampsia had 14.5% lower serum vitamin D levels than women in the control group (16.5 ng/ml vs. 19 ng/ml, p = 0.014) with 64.5% higher sFlt-1 levels (11,600 pg/ml vs. 7050 pg/ml, p < 0.001) and greater than 2 times higher endoglin levels (18.6 ng/ml vs. 8.7 ng/ml, < 0.001). After controlling for gestational age at delivery and maternal BMI, vitamin D levels were 0.88 times lower (P = 0.051), while endoglin levels were 2.5 times higher and sFlt-1 levels were 2.1 times higher than in control pregnancies (P < 0.001). CONCLUSIONS: Women with preeclampsia at time of delivery have higher maternal antiangiogenetic factors and may have lower maternal serum vitamin D levels. These findings may lead to a better understanding of the underlying etiology of preeclampsia as well as possible modifiable treatment options which could include assuring adequate levels of maternal serum vitamin D prior to pregnancy.

PET study of ocular and blood pharmacokinetics of intravitreal bevacizumab and aflibercept in rats.

Intravitreal injections are the standard procedure in the treatment of retinal pathologies, such as the administration of the anti-VEGF antibodies in age-related macular degeneration. The aim of this study is to evaluate the intraocular and blood pharmacokinetics after an intravitreal injection of 89Zr-labelled bevacizumab and 89Zr-labelled aflibercept in Sprague-Dawley rats using Positron Emission Tomography. First, both antibodies were radiolabelled to zirconium-89 with a maximum specific activity of 15 Mbq/mg for bevacizumab and 10 Mbq/mg for aflibercept. Four µL containing 1-1.2 Mq of 89Zr-labelled compound were injected into the vitreous through a 35 G needle. A microPET acquisition was carried out immediately after the injection and at different time points through a 12-day study and blood samples were obtained through the tail vein. Radiolabelling was successfully performed with a radiochemical purity after ultrafiltration above 95% for both agents. Both antibodies ocular curves followed a two-compartment model in which an intraocular elimination half-life of 16.44 h was found for 89Zr-bevacizumab and 4.51 h for 89Zr-aflibercept, considering the alpha phase as the elimination phase. Regarding the beta phase, a half-life of 3.23 days for 89Zr-bevacizumab and 4.69 days for 89Zr-aflibercept were observed. With regards to blood concentration, 89Zr-bevacizumab showed a blood half-life of 7.08 days, whereas 89Zr-aflibercept's was 3.18 days, by a one-compartment model with first-order absorption kinetics. In conclusion, this study shows for the first time the ocular and blood pharmacokinetic analysis after intravitreal injection of aflibercept and bevacizumab in rats.

Possibility for Dose Optimization of Pazopanib from Its Plasma Concentration in Japanese Patients with Cancer.

The currently approved dose of pazopanib (800 mg) is being re-examined owing to its adverse effects. The aim of this study was to evaluate the relationships among starting or maintenance doses of pazopanib, estimated pazopanib Cmin, and other clinical factors, including albumin and α-1 acid glycoprotein levels, in soft-tissue sarcoma and renal cell carcinoma. We also determined whether therapeutic drug monitoring of pazopanib concentrations may be used to improve its therapeutic efficacy and prevent adverse effects. Forty patients who received pazopanib for renal cancer or soft-tissue sarcoma at the Hokkaido Cancer Center were evaluated prospectively. Cmin for pazopanib was calculated based on the measured values from the plasma samples. The efficacy and time to treatment failure were then assessed. The pazopanib maintenance doses were 200 (n = 4), 400 (n = 34), 600 (n = 4), and 800 mg (n = 1). Most patients (65%) who received a 400 mg dose had an effective pazopanib concentration (≧20 µg/mL), whereas 35% of patients who received the 400 mg dose had ineffective concentrations (<20 µg/mL). Logistic regression analysis revealed that only the albumin level was significantly associated with effective pazopanib concentrations (odds ratio: 1.37, p = 0.0234). In conclusion, a dose of 400 mg had been effective and well tolerated in more than half of patients in this study. However, therapeutic drug monitoring is necessary during pazopanib therapy.

Plasma vasohibin-1 and vasohibin-2 are useful biomarkers in patients with esophageal squamous cell carcinoma.

BACKGROUND: Vasohibins (VASH), which are angiogenesis regulators, consist of Vasohibin-1 (VASH1) and Vasohibin-2 (VASH2). VASH1 is an angiogenesis inhibitor, while VASH2 is a proangiogenic factor. Patients with esophageal squamous cell carcinoma (ESCC) with high tumor expression levels of VASH1 and VASH2 have been reported to show a poor prognosis. The clinical significance of VASH concentrations in the blood of patients with ESCC has not yet been investigated. METHODS: Plasma samples from 89 patients with ESCC were analyzed, and the relationships between the plasma VASH concentrations and the clinicopathological factors of the patients were evaluated. Immunohistochemical examination (IHC) of the resected tumor specimens for VASH was performed in 56 patients, and the correlation between the plasma VASH concentrations and tumor expression levels of VASH was analyzed. RESULTS: The patient group with high plasma concentrations of VASH1 showed a higher frequency of lymph node metastasis (P = 0.01) and an invasive growth pattern (P = 0.05). Furthermore, poorly differentiated cancer occurred at a higher frequency in the patient group with high plasma concentrations of VASH2 (P < 0.01). High tumor expression levels of VASH1 were encountered more frequently in the patient group with high plasma concentrations of VASH1 (P = 0.03), and high tumor expression levels of VASH2 were encountered more frequently in the patient group with high plasma concentrations of VASH2 (P = 0.04). CONCLUSIONS: In patients with ESCC, high plasma concentrations were associated with poor clinical outcomes for both VASH1 and VASH2. We propose that results indicate that plasma VASH1 and VASH2 are useful biomarkers in patients with ESCC.

Phase I dose-escalation study of the safety, tolerability, and pharmacokinetics of aflibercept in combination with S-1 in Japanese patients with advanced solid malignancies.

Background Aflibercept, a recombinant fusion protein binding VEGF-A, VEGF-B and placental growth factor, inhibits tumor growth by blocking angiogenesis. The aim of this phase I dose-escalation study was to determine the recommended phase II dose (RP2D) of aflibercept in combination with S-1 in Japanese patients with solid tumors. Patients and methods Sequential cohorts of 3-6 patients with metastatic or unresectable solid tumors, who had failed at least one prior line of standard treatment or who were not suitable for such treatment, were to receive escalating doses of aflibercept every 2 weeks, starting at 2 mg/kg, combined with S-1 at 40 mg/m2 twice daily (80 mg/m2/day; 4 weeks on/2 weeks off). Dose-escalation was to be based on the incidence of dose-limiting toxicity (DLT). Blood samples were collected for pharmacokinetic analysis. Results At the first dose level (aflibercept 2 mg/kg plus S-1) 1 of 6 patients experienced a DLT (grade 4 proteinuria). The aflibercept dose was consequently escalated to 4 mg/kg; 1 of 3 patients treated at this dose level had a DLT (grade 2 pleural effusion), and another patient experienced grade 3 reversible posterior leukoencephalopathy syndrome after the DLT assessment period. Additional patients were therefore enrolled into the first dose level to explore safety and tolerability. The study was subsequently terminated prematurely. The maximum tolerated dose was not reached and the RP2D was not determined in Japanese patients. Conclusions The tolerability and safety of aflibercept 2 mg/kg in combination with S-1 was confirmed in Japanese patients with advanced solid tumors.

Development of a mono-specific anti-VEGF bivalent nanobody with extended plasma half-life for treatment of pathologic neovascularization.

Vascular endothelial growth factor (VEGF) plays a crucial role in angiogenesis within solid cancers. Thus, targeting VEGF might be part of a feasible therapy for treating pathological neovascularization, and nanobodies - derived from heavy chain-only antibodies occurring within Camelidae - are a novel class of nanometer-sized antibodies possessing unique properties that could be developed into a promising therapeutic. However, nanobodies have a very short half-life in vivo due to their small size. Development of a bivalent nanobody is one way to remediate the half-life problem of nanobodies. Two identical anti-VEGF nanobodies were connected using the hinge region of llama IgG2c. The recombinant plasmid (pHEN6c-bivalent nanobody) was transformed into E.coli WK6 cells and expression of the bivalent nanobody construct was induced with 1mM Isopropyl ß-D-1-thiogalactopyranoside (IPTG). Recombinant bivalent nanobody was purified using nickel affinity chromatography and its activity on human endothelial cells was assessed using 3-(4,5-Dimethylthiazol-2-yr)-2,5-diphenyltetrazolium bromide (MTT), tube formation, and cell migration assays. The pharmacokinetic study was performed after intravenous (i.v.) injection of recombinant bivalent nanobody into six-week-old C57BL/6 mice. Recombinant bivalent nanobody performed significantly better than monovalent nanobody in inhibiting proliferation, tube formation, and migration of human endothelial cells. Pharmacokinetic results showed a 1.8-fold longer half-life of bivalent nanobody in comparison with the monovalent nanobody. These results underscore the potential of recombinant anti-VEGF bivalent nanobody as a promising tool for development of a novel therapeutic with an extended plasma half-life for VEGF-related diseases.

Production of monoclonal antibodies for measuring Avastin and its biosimilar by Sandwich ELISA.

The development of Bevacizumab (Avastin) biosimilar products has grown rapidly over the last ten years as the original Avastin's patent will expire soon. The approval of Avastin biosimilars requires the demonstration of similarity between the biosimilar and the reference product. To support pre-clinical and clinical studies, pharmacokinetic (PK) assays are required to measure the biosimilar and Avastin with comparable precision and accuracy. The PK assay of Avastin employed by Genentech was a Sandwich ELISA which could detect the total drug concentration. However, it was developed in-house and not commercially available. Therefore, in most of the Avastin biosimilar pre-clinical studies, the antibody drug concentrations were measured using an indirect ELISA against coated VEGF, which could only measure the free instead of the total antibody drugs. It failed the essential requirement to develop the biosimilars. In this study, we reported the generation of mouse monoclonal antibodies (mAbs) that specifically recognize Avastin in a VEGF non-competitive manner. Using a pair of non-VEGF competing anti-Avastin mAbs, a Sandwich ELISA was developed with a lower limit of quantitation (LLOQ) at 400 ng/mL and upper limit of quantitation (ULOQ) at 12800 ng/mL. The assay validation was carried out with serum samples from monkey treated with Avastin biosimilar at seven different time points. Our data showed that the Sandwich ELISA kit we developed is sensitive, simple, reproducible and ready for use in human clinical trials.

Impact of CYP3A4*22 on Pazopanib Pharmacokinetics in Cancer Patients.

BACKGROUND AND OBJECTIVE: As pazopanib plasma trough concentrations are correlated with treatment outcome, we explored whether single nucleotide polymorphisms in the elimination pathway of pazopanib affect systemic pazopanib concentrations. METHODS: The decreased function alleles CYP3A4 15389 C > T (*22), ABCB1 3435 C >T, ABCG2 421 C >A, and ABCG2 34G >A were analyzed within a recently developed population-pharmacokinetic model. RESULTS: Incorporation of CYP3A4*22 in the model resulted in a 35% lower clearance for variant carriers (0.18 vs. 0.27 L/h; difference in objective function value: - 9.7; p < 0.005). Simulated median trough concentrations of cancer patients with CYP3A4*22 with 600 mg once daily or 800 mg once daily were 31 and 35 mg/L, respectively. The simulated trough concentrations for the population excluding the CYP3A4*22 carriers after 600 mg once daily or 800 mg once daily were 18 and 20 mg/L, respectively. CONCLUSION: This analysis shows that CYP3A4*22 heterozygotes have a substantial lower pazopanib clearance and that dose adjustments based on CYP3A4*22 status could be considered.

Harnessing soft tissue sarcoma with low-dose pazopanib - a matter of blood levels.

BACKGROUND: Pazopanib is a tyrosine kinase inhibitor indicated for the treatment of renal cell carcinoma and soft tissue sarcoma. Despite the high inter-patient variability in pharmacokinetic exposure, pazopanib is administered at a fixed dose of 800 mg once daily (QD). Pharmacokinetic exposure is linked to both efficacy and toxicity. In this case report, we illustrate the value of therapeutic drug monitoring by describing two patients with adequate pazopanib trough concentrations (Cmin) at an eight times lower than standard dose. CASE PRESENTATION: Patient A is a 69-year-old woman with metastatic leiomyosarcoma who had significant toxicities and a high Cmin on the standard dose. While dose reductions to 200 mg QD and later 200 mg every other day were made, pazopanib Cmin remained above the efficacy threshold. Patient B is a 50-year-old male with metastatic angiosarcoma and a history of Gilbert syndrome. Pazopanib treatment was initiated at the standard dose of 800 mg QD, but was reduced to 200 mg QD 1-week-on - 1-week-off due to total bilirubin elevation. Pazopanib Cmin was adequate in this patient as well. CONCLUSION: It could be valuable to measure pazopanib levels in case of dose reductions due to toxicity, as exposure could still be adequate at considerably lower than standard doses.

Branched pentapeptides as potent inhibitors of the vascular endothelial growth factor 165 binding to Neuropilin-1: Design, synthesis and biological activity.

The demonstrated involvement of VEGF165/NRP-1 complex in pathological angiogenesis has catalyzed interest in blocking this interaction to combat angiogenesis dependent diseases. It was shown before that Lys-Pro-Pro-Arg is a fairly strong inhibitor of the VEGF165/NRP-1 interaction. Our current findings suggest that the side chain elongation of the Lys1 by branching it with additional homoarginine (Har) residue, to obtain Lys(Har)-Pro-Pro-Arg, allows more effective inhibition. Moreover, increasing the flexibility of the middle part of molecule, in particular with simultaneous introduction of additional interacting elements at the second or third position, produced compounds up to 30-fold more active (IC50 = 0.2 µM) than the heptapeptide ATWLPPR (A7R) which is one of the first peptide known as an effective antagonist of the VEGF165 binding to NRP-1 and in vivo decreases breast cancer angiogenesis and growth. Herein, we present also the structure-activity study of Lys(Har)-Pro-Pro-Arg, discussing the design, synthesis, inhibitory activity, proteolytic stability and molecular modeling of the prepared derivatives. For two of the most active analogs the high proteolytic stability was also observed. These studies provide the next step for elucidating the optimal structure of the small peptidic inhibitors of VEGF165/NRP-1 interaction that could serve as research tools or be prospective drug candidates.

A LC-MS/MS method to monitor the concentration of HYD-PEP06, a RGD-modified Endostar mimetic peptide in rat blood.

HYD-PEP06 is a novel RGD-modified Endostar mimetic peptide with 30 amino acids that is intended to suppress the formation of neoplasm vessels. This assay was developed and validated to monitor the level of the peptide HYD-PEP06 in rat blood, using liquid chromatography tandem mass spectrometry (LC-MS/MS). HYD-PEP10, another peptide similar to the analyte, was used as an internal standard (IS). A triple quadrupole mass spectrometry in Multiple Reaction Monitoring (MRM) mode and an electrospray interface (ESI) in the positive mode were used for MS analysis. The analysis was optimized with addition of 0.3% formic acid (FA) into the mobile phase as well as with a needle washing solution to overcome the carryover effect. In addition, the carryover was reduced by optimizing the mobile phase gradient. Methanol was used as a diluent of working solutions to avoid any adsorption. Methanol:acetonitrile (1:1, v:v) containing 0.3% FA was employed to precipitate the blood samples. Unknown blood samples must be placed in ice bath immediately, and precipitating agents should be added within 30 min to ensure the stability of blood samples. The assay was established and validated. This method showed a good linear relationship for the HYD-PEP06 in the range of 10 ng·mL-1 to 2000 ng·mL-1, with R > 0.99. HYD-PEP06 was determined with accuracy values (RE%) of -5.06%-8.54%, intra- and inter-day precisions (RSD%) of 3.13%-4.87% and 4.81%-9.42%. The method was successfully in monitoring the concentration of HYD-PEP06 in rat blood.

Solubility and bioavailability improvement of pazopanib hydrochloride.

The anti-cancer drug pazopanib hydrochloride (PZH) has a very low aqueous solubility and a variable oral bioavailability. A new pharmaceutical formulation with an improved solubility may enhance the bioavailability and reduce the variability. A broad selection of polymer excipients was tested for their compatibility and solubilizing properties by conventional microscopic, thermal and spectrometric techniques. A wet milling and mixing technique was used to produce homogenous powder mixtures. The dissolution properties of the formulation were tested by a pH-switch dissolution model. The final formulation was tested in vivo in cancer patient following a dose escalation design. Of the tested mixture formulations, the one containing the co-block polymer Soluplus® in a 8:1 ratio with PZH performed best in terms of in vitro dissolution properties. The in vivo results indicated that 300 mg of the developed formulation yields similar exposure and a lower variability (379 µg/mL∗h (36.7% CV)) than previously reported values for the standard PZH formulation (Votrient®) at the approved dose of 800 mg. Furthermore, the expected plasma-Cthrough levels (27.2 µg/mL) exceeds the defined therapeutic efficacy threshold of 20 µg/mL.

Nonclinical assessments of the potential biosimilar PF-06439535 and bevacizumab.

Bevacizumab, a recombinant humanized monoclonal antibody targeting vascular endothelial growth factor (VEGF), is approved for treatment of metastatic colorectal cancer, nonsquamous non-small-cell lung cancer, metastatic kidney cancer, and glioblastoma. To support clinical development of the potential bevacizumab biosimilar PF-06439535, nonclinical studies evaluated structural, functional, toxicological, and toxicokinetic similarity to bevacizumab sourced from the European Union (bevacizumab-EU) and United States (bevacizumab-US). Peptide mapping demonstrated the amino acid sequence of PF-06439535 was identical to bevacizumab-EU and bevacizumab-US. Biologic activity, measured via inhibition of VEGF-induced cell proliferation in human umbilical vein endothelial cells and binding to VEGF isoforms, was similar across the three drugs. In vivo similarity was demonstrated in cynomolgus monkeys administered intravenous PF-06439535 or bevacizumab-EU (0 or 10 mg/kg/dose twice weekly for 1 month; total of nine doses). Systemic exposure appeared similar and test article-related effects were limited to physeal dysplasia of the distal femur. The potential for non-target-mediated toxicity of PF-06439535 was evaluated in rats administered intravenous PF-06439535 (15 or 150 mg/kg/dose twice weekly for 15 days; total of five doses). Nonadverse higher liver weights and minimal sinusoidal cell hyperplasia were observed. Collectively, these studies demonstrated similarity of PF-06439535 to bevacizumab, supporting entry into clinical development.

Development and Validation of a Simultaneous Quantification Method of Ruxolitinib, Vismodegib, Olaparib, and Pazopanib in Human Plasma Using Liquid Chromatography Coupled With Tandem Mass Spectrometry.

BACKGROUND: A simple, rapid, and sensitive liquid chromatography coupled with tandem mass spectrometry method has been developed and validated for the quantification of ruxolitinib, olaparib, vismodegib, and pazopanib in human plasma. METHODS: After a simple protein precipitation of plasma samples, the chromatographic separation was performed using an ultraperformance liquid chromatography system coupled with mass tandem spectrometry in a positive ionization mode. The mobile phase consisted of a gradient elution of 10-mmol/L formate ammonium buffer containing 0.1% (vol/vol) formic acid (phase A) and acetonitrile with 0.1% (vol/vol) formic acid (phase B) at a flow rate at 300 µL/min. RESULTS: Analysis time was 5.0 minutes per run, and all analytes and internal standards eluted within 1.5-1.73 minutes. The calibration curves were linear over the range from 10 to 2500 ng/mL for ruxolitinib and from 100 to 100,000 ng/mL for olaparib, vismodegib, and pazopanib with coefficients of correlation above 0.99 for all analytes. The intraday and interday coefficients of variation were below 14.26% and 14.81%, respectively, for lower concentration and below 9.94% and 6.37%, respectively, for higher concentration. CONCLUSIONS: Using liquid chromatography coupled with tandem mass spectrometry, we have developed and validated a simple and rapid assay for the simultaneous quantification of olaparib, vismodegib, pazopanib, and ruxolitinib in human plasma. This method is now part of our therapeutic drug monitoring service provision and is currently used clinically to manage patients prescribed these drugs.

A Proximity Extension Assay (PEA)-based method for quantification of bevacizumab.

INTRODUCTION: Proximity Extension Assay (PEA) is a direct one-step protein quantification method using a pair of DNA oligonucleotides linked to antibodies against the target molecule. It requires polyclonal or two monoclonal antibodies (mAbs) that bind to target epitopes close enough to form a DNA duplex which is quantified by real-time PCR. Bevacizumab, an anti-cancer drug, is a mAb against vascular endothelial growth factor with common cardiovascular adverse effects. It is widely used off-label to treat neovascular eye disorders by intravitreal application of small doses. Even then, certain amount reaches systemic circulation which is considered relevant regarding safety. We aimed to set-up a PEA-based assay for bevacizumab in human plasma and to preliminary evaluate it in patients treated intravitreally. METHODS: We tested (PEA, quantitative PCR) several combinations of commercial mAbs and a Fab fragment against bevacizumab. The best combination was used to quantify bevacizumab in three patients donating plasma before and 24 h after the first intravitreal injection. RESULTS: A combination of a mAb and a Fab fragment (HCA184 and HCA182, Bio-Rad Laboratories, Inc.) performed best: standard curve R2 0.98, linear dynamic range 1-1000 pM, lower limit of quantification 1 pM (149 pg/mL) and a satisfactory precision (coefficient of variation 12%). All pre-dose patient concentrations were zero, while post-dose concentrations were 10.94, 13.73 and 55.49 ng/mL, in line with previous reports. DISCUSSION: This is the first set-up of a PEA-based assay for quantification of bevacizumab in human plasma. Its good performance and high sensitivity support further evaluation for potential uses particularly when the expected concentrations are low.

Fast and Straightforward Method for the Quantification of Pazopanib in Human Plasma Using LC-MS/MS.

BACKGROUND: Pazopanib is an angiogenesis inhibitor approved for renal cell carcinoma and soft-tissue sarcoma. Studies indicate that treatment with pazopanib could be optimized by adapting the dose based on measured pazopanib plasma concentrations. METHODS: We describe the validation and clinical application of a fast and straightforward method for the quantification of pazopanib in human plasma for the purpose of therapeutic drug monitoring and bioanalytical support of clinical trials. Stable isotopically labeled C,H3-pazopanib was used as internal standard. Plasma samples were prepared for analysis by protein precipitation using methanol and diluted with 10 mmol/L ammonium hydroxide buffer. Chromatographic separation was performed on a C18 column using isocratic elution with ammonium hydroxide in water and methanol. For detection, a tandem mass spectrometer, equipped with a turbo ion spray interface was used in positive ion mode at m/z 438 → m/z 357 for pazopanib and m/z 442 → m/z 361 for the internal standard. RESULTS: Final runtime was 2.5 minutes. All validated parameters were within pre-established limits and fulfilled the FDA and EMA requirements for bioanalytical method validation. After completion of the validation, the routine application of the method was tested by analyzing clinical study samples that were collected for the purpose of therapeutic drug monitoring. CONCLUSIONS: In conclusion, the described method was successfully validated and was found to be robust for routine application to analyze samples from cancer patients treated with pazopanib.

Diclofenac sex-divergent drug-drug interaction with Sunitinib: pharmacokinetics and tissue distribution in male and female mice.

Coadministration of diclofenac and sunitinib, tyrosine kinase inhibitor, led to sex-divergent pharmacokinetic drug-drug interaction outcomes. Male and female mice were administered 60 mg/kg PO sunitinib alone (control groups) or with 30 mg/kg PO diclofenac. Sunitinib concentration in plasma, brain, kidney and liver were determined by HPLC and non-compartmental pharmacokinetic parameters calculated. In male mice, diclofenac decreased AUC0→∞ 38% in plasma (p < 0.05) and 24% in liver (p < 0.001) and 23% in kidney (p < 0.001). However, AUC0→∞ remained unchanged in plasma and increased 41% in kidney (p < 0.001) of female mice. In brain, sunitinib exposure decreased 46% (p < 0.001) and 32% (p < 0.001) in male and female brain respectively. Mechanistically, diclofenac increased the liver uptake efficiency in male (27%, p < 0.05) and female (48%, p < 0.001) mice and 30% in kidney (p < 0.05) of male mice, probably owing to effects on efflux transporters. Sunitinib displayed sex-divergent DDI with diclofenac with probable clinical translatability due to potential different effects in male and female patients requiring careful selection of the NSAID and advanced TDM to implement a personalized treatment.

Sunitinib-paracetamol sex-divergent pharmacokinetics and tissue distribution drug-drug interaction in mice.

The sex-divergent pharmacokinetics and interaction of tyrosine kinase inhibitor sunitinib with paracetamol was evaluated in male and female mice. Mice (control groups) were administered 60 mg/kg PO sunitinib alone or with 200 mg/kg PO paracetamol (study groups). Sunitinib concentration in plasma, brain, kidney and liver were determined and non-compartmental pharmacokinetic analysis performed. Female control mice showed 36% higher plasma sunitinib AUC0→∞, 31% and 27% lower liver and kidney AUC0→∞ and 2.2-fold higher AUC0→∞ in brain (all p < 0.001) and had lower liver- and kidney-to-plasma AUC0→∞ ratios (p < 0.001) than male control mice. Paracetamol decreased 29% plasma AUC0→∞ (p < 0.05) in male mice and remained unchanged in female mice. In male and female mice, it decreased liver (15%, 9%), kidney (15%, 20%) and brain (47%, 50%) AUC0→∞ (p < 0.001) respectively owing to 52% brain uptake efficiency reduction in female mice (p < 0.01). Sunitinib displayed sex-divergent pharmacokinetics, tissue distribution and DDI with potential clinical translatability for the treatment of brain tumor and RCC patients.

Angiogenic and Antiangiogenic Markers for Prediction and Risk Classification of Preeclampsia.

Preeclampsia is a pregnancy-specific hypertensive disorder with multisystem involvement and is a significant cause of obstetric morbidity and mortality worldwide. A major issue in the treatment of preeclampsia stems from its still significant rates of misclassification and misdiagnosis. Angiogenic factors have been speculated as a possible diagnostic modality due to a perceived imbalance in angiogenesis in preeclampsia. Factors currently studied include soluble fms-like protein kinase 1 and placental growth factor. Because of significant mortality associated with preeclampsia it is felt that both early and accurate diagnosis of preeclampsia is imperative if this disease process is to be treated.

Correlation between maternal serum-amniotic fluid anti-angiogenic factors and uterine artery Doppler indices.

PURPOSE: Elevated sFlt-1 and sEng is usually a clue for impending preeclampsia and intrauterine growth restriction. Likewise, uterine artery Doppler ultrasound is being investigated for prediction of similar conditions. In this study, we aimed to explore the possible relations of these two proteins in different body compartments with uterine artery Doppler indices (UtAD) in a healthy second trimester obstetric population. METHODS: Levels of sFlt-1 and sEng were measured in serum and amniotic fluid samples of 43 patients. UtAD were measured on the days of sample collections. Findings were then analyzed for possible correlation. RESULTS: There was a positive correlation between the levels of maternal serum sFlt-1 (MSsFlt-1) and sEng levels (MSsEng) (r= 0.516, p< 0.001). The negative correlation between MSsFlt-1 and UtAD was disappeared after elimination of poor obstetric outcome pregnancies (r= -0.371, p= 0.016). No correlation was found between UtAD and studied protein levels in amniotic fluid. Mean MSsFlt-1 level was 305.2 ± 220.1 pg/ml and mean AFsFlt-1 was 48.9 ± 11.8 ng/ml. Mean MSsEng level was 4.5 ± 1.3 ng/ml, mean AFsEng level was found 0.7 ± 0.3 ng/ml. Mean values for UtAD were 1.3 ± 0.4, 0.6 ± 0.1 and 3.5 ± 1.3 for PI, RI, and S/D, respectively. CONCLUSION: In normal second trimester pregnancies, there is a positive correlation between serum levels of sFlt-1 and sEng levels. Amniotic fluid levels of sEng and sFlt-1 are not correlated with UtAD in uncomplicated pregnancies.