Phase 1 clinical trial of the novel proteasome inhibitor marizomib with the histone deacetylase inhibitor vorinostat in patients with melanoma, pancreatic and lung cancer based on in vitro assessments of the combination

PURPOSE

Combining proteasome and histone deacetylase (HDAC) inhibition has been seen to provide synergistic anti-tumor activity, with complementary effects on a number of signaling pathways. The novel bi-cyclic structure of marizomib with its unique proteasome inhibition, toxicology and efficacy profiles, suggested utility in combining it with an HDAC inhibitor such as vorinostat. Thus, in this study in vitro studies assessed the potential utility of combining marizomib and vorinostat, followed by a clinical trial with the objectives of assessing the recommended phase 2 dose (RP2D), pharmacokinetics (PK), pharmacodynamics (PD), safety and preliminary anti-tumor activity of the combination in patients.

EXPERIMENTAL DESIGN

Combinations of marizomib and vorinostat were assessed in vitro. Subsequently, in a Phase 1 clinical trial patients with melanoma, pancreatic carcinoma or Non-small Cell Lung Cancer (NSCLC) were given escalating doses of weekly marizomib in combination with vorinostat 300 mg daily for 16 days in 28 day cycles. In addition to standard safety studies, proteasome inhibition and pharmacokinetics were assayed.

RESULTS

Marked synergy of marizomib and vorinostat was seen in tumor cell lines derived from patients with NSCLC, melanoma and pancreatic carcinoma. In the clinical trial, 22 patients were enrolled. Increased toxicity was not seen with the combination. Co-administration did not appear to affect the PK or PD of either drug in comparison to historical data. Although no responses were demonstrated using RECIST criteria, 61% of evaluable patients demonstrated stable disease with 39% having decreases in tumor measurements.

CONCLUSIONS

Treatment of multiple tumor cell lines with marizomib and vorinostat resulted in a highly synergistic antitumor activity. The combination of full dose marizomib with vorinostat is tolerable in patients with safety findings consistent with either drug alone.

Drug interaction profile for GSK2248761, a next generation non-nucleoside reverse transcriptase inhibitor

AIM

To evaluate potential drug interactions with antiretroviral therapies or supportive therapies for use in conjunction with the once daily, next generation non-nucleoside reverse transcriptase inhibitor GSK2248761 in patients with HIV-1 infection.

METHODS

A series of phase I drug interaction studies was conducted.

RESULTS

GSK2248761 was shown to be a weak CYP3A4 and CYP2D6 inhibitor in a clinical study with a probe cocktail. Mean plasma concentration-time profiles for atazanavir, tenofovir disoproxil fumarate/emtricitabine (TDF/FTC), darunavir (DRV, administered with ritonavir [RTV]), and drospirenone/ethinylestradiol were similar following co-administration of GSK2248761. Plasma raltegravir AUC(0,τ) and C(max) increased by 18% with no change in Cτ when raltegravir was co-administered with GSK2248761. Lopinavir (LPV) plasma AUC(0,τ), C(max) and Cτ decreased by 23%, 14% and 40%, respectively, following administration of lopinavir/ritonavir with GSK2248761. Atorvastatin, rosuvastatin and simvastatin AUC(0,∞) and C(max) increased following co-administration with GSK2248761, with the largest changes observed for simvastatin (3.7-fold and 4.3-fold). Changes in maximum and extent of GSK2248761 exposure were marginal after co-administration with atazanavir, TDF/FTC and raltegravir compared with GSK2248761 administered alone. Co-administration of GSK2248761 with DRV/RTV and LPV/RTV increased plasma GSK2248761 exposures by 1.25- to ≤2-fold compared with GSK2248761 administered alone, and increases in GSK2248761 exposure were higher following single dose co-administration of DRV/RTV or LPV/RTV compared with multiple doses. There were few drug-related AEs, and no treatment-related trends in blood chemistry, haematology, urinalysis, vital signs or ECG findings.

CONCLUSIONS

These studies indicate that GSK2248761 was safe and well tolerated in healthy adults treated in these studies at the doses and duration of therapy evaluated.

A biodegradable perivascular wrap for controlled, local and directed drug delivery

Perivascular delivery of anti-proliferative agents is an attractive approach to inhibit hyperplasia that causes stenosis of synthetic hemodialysis grafts and other vascular grafts. Perivascular drug delivery systems typically release drugs to both the vascular wall and non-target extravascular tissue. The objective of this study was to develop a biodegradable, perivascular delivery system for localized, sustained and unidirectional drug release in the context of synthetic arteriovenous (AV) grafts used for chronic hemodialysis. To this end, a dense non-porous polymer barrier layer was laminated to either i) a drug-loaded non-porous polymer layer or ii) a porous polymer layer. To provide tunability, the porous layer could be loaded with drug during casting or later infused with a drug-loaded hydrogel. The polymer bilayer wraps were prepared by a solvent casting, thermal-phase inversion technique using either polylactide-co-glycolide (PLGA) or polycaprolactone (PCL). Sunitinib, a multi-target receptor tyrosine kinase inhibitor, was used as a model drug. In a modified transwell chamber system, the barrier function of the non-porous PLGA backing was superior to the non-porous PCL backing although both markedly inhibited drug diffusion. As assessed by in vitro release assays, drug release duration from the drug-loaded non-porous PCL construct was almost 4-fold greater than release from the porous PCL construct infused with drug-laden hydrogel (22 days vs. 5 days); release duration from the drug-loaded non-porous PLGA construct was prolonged approximately 3-fold over release from the porous PLGA construct infused with drug-laden hydrogel (9 days vs. 3 days). Complete in vitro degradation of the PLGA porous and non-porous constructs occurred by approximately 35 days whereas the PCL constructs remained intact even after most of the drug was released (49 days). The PLGA non-porous bilayer wrap containing 143±5.5mg sunitinib in the inner layer was chosen for further pharmacokinetic assessment in vivo where the construct was placed around the external jugular vein in a porcine model. At 1 week, no drug was detected by HPLC/MS/MS in any examined extravascular tissue whereas high levels of drug were detected in the wrapped vein segment (1048 ng g⁻¹ tissue). At 4 weeks, drug was detected in adjacent muscle (52 ng g⁻¹ tissue) but 13-fold greater amounts were detected in the wrapped vein segment (1742 ng g⁻¹ tissue). These results indicate that the barrier layer effectively impedes extravascular drug loss. Tensile testing showed that the initially flexible PLGA construct stiffened with hydration, a phenomenon also observed after in vivo placement. This characteristic may be useful to resist undue circumferential venous tensile stress produced in AV grafting. The PLGA wrap bilayer formulation is a promising perivascular drug delivery design for local treatment of hemodialysis AV graft hyperplasia and possibly other hyperplastic vascular disorders.

A phase I study of sunitinib combined with modified FOLFOX6 in patients with advanced solid tumors

PURPOSE

This phase I study assessed the safety, tolerability, maximum tolerated dose (MTD), pharmacokinetics, and preliminary antitumor effects of sunitinib combined with modified FOLFOX6 (mFOLFOX6).

METHODS

Patients with advanced solid malignancies received mFOLFOX6 in 2-week cycles with escalating sunitinib doses (25, 37.5, and 50 mg/day) on three schedules: 2 weeks on, 2 weeks off (2/2); 4 weeks on, 2 weeks off (4/2); or continuous daily dosing (CDD). Patients received up to 8 treatment cycles (Schedule 2/2 and CDD schedule) or 6 cycles (Schedule 4/2). An expansion cohort enrolled patients with metastatic colorectal cancer at the Schedule 2/2 MTD.

RESULTS

Overall, 53 patients were enrolled, with 43 evaluable for dose-limiting toxicity (DLT). On Schedule 2/2 (n = 18), DLTs occurred in three patients at 50 mg/day (grade 4 neutropenia [n = 1]; grades 3 and 4 thrombocytopenia [n = 2]) and two patients achieved partial responses (PRs). On Schedule 4/2 (n = 13), 37.5 mg/day exceeded the MTD with two DLTs (febrile neutropenia and grade 4 hypokalemia, respectively). On the CDD schedule (n = 12), the MTD was 25 mg/day; one DLT (grade 3 stomatitis) was reported and two patients achieved PRs. The most common adverse events were neutropenia, fatigue, and thrombocytopenia. No clinically significant drug-drug interactions were apparent between sunitinib, its metabolite SU12662, and mFOLFOX6.

CONCLUSIONS

Sunitinib combined with mFOLFOX6 had acceptable tolerability. The MTDs were sunitinib 50 mg/day on Schedule 2/2 and 25 mg/day on the CDD schedule. A MTD for Schedule 4/2 was not established.

[Pharmacokinetics and bioequivalence of atorvastatin calcium tablets in healthy male Chinese volunteers]

OBJECTIVE

To compare the bioequivalence and pharmacokinetics of national made and imported atorvastatin in healthy male Chinese volunteers after single oral administration.

METHODS

This randomized sequence, open-label, two-period crossover study with a one-week washout period between doses was performed in 24 fasting healthy Chinese males. They were randomly assigned to receive 20 mg of either the test (national made) or reference (imported) formulation orally. The blood samples were collected over a 72-hour period. Plasma concentrations of parent atorvastatin (AT), ortho-hydroxy-atorvastatin (o-OAT) and para-hydroxy-atorvastatin (p-OAT) were simultaneously determined using the validated liquid chromatography-tandem mass spectrometry method, the bioequivalence was also evaluated throughout the study.

RESULTS

The main pharmacokinetic parameters of test and reference formulations were as follows: the values of C(max) for AT were (10.6 ± 11.9) µg/L and (10.6 ± 9.8) µg/L, t(1/2z) were (11.4 ± 3.9) h and (11.4 ± 5.3) h, AUC(0-t) were (54.2 ± 37.4) µg×h(-1)×L(-1) and (51.7 ± 34.1) µg×h(-1)×L(-1), respectively. The values of C(max) for o-OAT were (7.8 ± 4.5) µg/L and (7.6 ± 4.3) µg/L, t(1/2z) were (12.3 ± 4.2) h and (11.9 ± 3.4) h, AUC(0-t) were (96.8 ± 48.2) µg×h(-1)×L(-1) and (92.3 ± 44.4) µg×h(-1)×L(-1), respectively. The values of C(max) for p-OAT were (0.5 ± 0.4) µg/L and (0.4 ± 0.3) µg/L, t(1/2z) were (18.4 ± 12.4) h and (23.3 ± 17.8) h, AUC(0-t) were (15.9 ± 12.3) µg×h(-1)×L(-1) and (13.8 ± 8.11) µg×h(-1)×L(-1), respectively. The relative bioavailability of AT and o-OAT in test formulation were (105.3 ± 20.7)% and (107.8 ± 23.2)%, respectively. The 90% confidence interval of the test/reference geometric mean ratios of AUC(0-t) for AT and o-OAT were (97.7 - 110.5)% and (98.3 - 111.3)%, C(max) for AT and o-OAT were (75.8 - 114.0)% and (90.6 - 122.9)%, they were all located within the bioequivalence criteria range (80% - 125% for AUC, and 70% - 143% for C(max)).

CONCLUSION

The result demonstrated that two formulations were bioequivalent.

Inhibition of hepatic uptake transporters by flavonoids

Members of the human SLC superfamily such as organic anion transporting polypeptide 1B1 (OATP1B1), OATP1B3, and organic cation transporter 1 (OCT1) are drug uptake transporters that are localised on the basolateral membrane of hepatocytes mediating the uptake of drugs such as atorvastatin and metformin into hepatocytes. Ingredients of food such as flavonoids influence the effects of drugs, e.g. by inhibition of drug transporters. Therefore, we investigated the impact of the Ginkgo biloba flavonoids apigenin, kaempferol, and quercetin, and the grapefruit flavonoids naringenin, naringin, and rutin on the OATP1B1, OATP1B3, and OCT1 transport activity. Transporter expressing HEK293 cell lines were used with [3H]sulfobromophthalein ([3H]BSP) as substrate for OATP1B1 and OATP1B3, [3H]atorvastatin as substrate for OATP1B1, and [3H]1-methyl-4-phenylpyridinium ([3H]MPP(+)) as substrate for OCT1. The G. biloba flavonoids showed a competitive inhibition of the OATP1B1- and OATP1B3-mediated [3H]BSP and the OATP1B1-mediated [3H]atorvastatin uptake. Quercetin was the most potent inhibitor of the OATP1B1- and OATP1B3-mediated [3H]BSP transport with K(i)-values of 8.8±0.8μM and 7.8±1.7μM, respectively. For the inhibition of the OATP1B1-mediated [3H]atorvastatin transport, apigenin was the most potent inhibitor with a K(i) value of 0.6±0.2μM. Among the grapefruit flavonoids, naringenin was the most potent inhibitor of the OATP1B1- and OATP1B3-mediated [3H]BSP transport with IC(50)-values of 81.6±1.1μM and 101.1±1.1μM, respectively. All investigated flavonoids showed no significant inhibition of the OCT1-mediated [3H]MPP(+) uptake. Taken together, these in vitro studies showed that the investigated flavonoids inhibit the OATP1B1- and OATP1B3-mediated drug transport, which could be a mechanism for food-drug interactions in humans.

Influence of atorvastatin on the pharmacodynamic and pharmacokinetic activity of repaglinide in rats and rabbits

Dyslipidemia is common in patients with type 2 diabetes. Statins are used as the first choice in treatment of diabetic dyslipidemia. Atorvastatin represents a first-line treatment option, alongside other hydroxyl methylglutaryl coenzyme A reductase inhibitors. Repaglinide is a short-acting, oral, insulin secretagogue that is used in the treatment of type 2 diabetes mellitus. Both the category of drugs undergo extensive metabolism with cytochrome enzyme system. This may lead to drug-drug interaction problems with altered repaglinide activity which is cautious. Repaglinide/atorvastatin/atorvastatin + repaglinide were administered orally to normal, diabetic rats, and to normal rabbits. Blood samples were collected at different time intervals and were analyzed for blood glucose by GOD-POD method using commercial glucose kits and repaglinide estimation in plasma by HPLC method. Diabetes was induced by alloxan 100 mg/kg body weight administered by I.P route. In the presence of atorvastatin, repaglinide activity was increased and maintained for longer period in diabetic rats compared with repaglinide matching control. The present study concludes co-administration of atorvastatin was found to improve repaglinide responses significantly in diabetic rats and improved glucose metabolism of atorvastatin played an important role and increased repaglinide levels by competitive CYP 3A4 enzyme inhibition by atorvastatin could be added advantage for anti hyperglycemic activity.

A phase I study of sunitinib in combination with FOLFIRI in patients with untreated metastatic colorectal cancer

BACKGROUND

This study evaluated the maximum tolerated dose (MTD) of sunitinib, a multitargeted tyrosine kinase inhibitor, combined with FOLFIRI (irinotecan 180 mg/m2 given over 90 min i.v. and l-leucovorin 200 mg/m2 given over 120 min on day 1, followed by 5-FU 400 mg/m2 bolus and then 2400 mg/m2 infused over 46 h) in untreated metastatic colorectal cancer (mCRC).

PATIENTS AND METHODS

In this multicentre, phase I, open-label, dose-finding trial, FOLFIRI was administered every 2 weeks. Two sunitinib regimens were explored: Schedule 4/2 (4 weeks on, 2 weeks off; 37.5 and 50 mg/day) and continuous daily dosing (CDD; 37.5 and 25 mg/day). Dose-limiting toxic toxicities (DLTs) were evaluated during weeks 1-6. Efficacy was a secondary objective.

RESULTS

Thirty-seven patients were enrolled. The 37.5 mg/day Schedule 4/2 cohort had zero of six DLTs, was expanded by 15 patients and declared the MTD. The MTD was exceeded at all other sunitinib doses and schedules; DLTs included febrile neutropenia (n=1), grade 4 neutropenia (n=4) and grade 3 deep vein thrombosis with grade 4 neutropenia (n=1). At the MTD, non-haematologic grade 3/4 adverse events with a frequency of >10% were diarrhoea, vomiting and lethargy, and the objective response rate was 57.9% (95% confidence interval 33.5-79.7).

CONCLUSIONS

The MTD of sunitinib combined with FOLFIRI in chemotherapy-naive mCRC was 37.5 mg/day on Schedule 4/2. CDD of sunitinib at 37.5 or 25 mg/day plus FOLFIRI was not feasible.

Preparation, physicochemical characteristics and bioavailability studies of an atorvastatin hydroxypropyl-beta-cyclodextrin complex

The aim of this study was to improve the solubility, stability and bioavailability of amorphous atorvastatin calcium (AT) by complexing it with hydroxypropyl-beta-cyclodextrin. The formation of the inclusion complexation was identified by molecular modeling, phase solubility diagrams, differential scanning calorimetry and X-ray powder diffractometry. Orally Disintegrating Tablets (ODT) were then manufactured by direct compression. Apart from improved stability compared to pure AT, disintegration time of 27s, hardness of 5 kg and favorable mouth feel were achieved. In vitro dissolution tests of the ODT of AT inclusion complex exhibited higher dissolution rates than those with pure drug and the commercial tablet Lipitor. In vivo bioavailability studies in rats also showed shorter T(max), higher C(max) and increased AUC of 4.42 and 1.86 fold compared to the plain drug ODT and Lipitor. These results strongly suggest to use HP-beta-CD to improve the physicochemical characteristics and bioavailability of AT.

A nonclinical safety and pharmacokinetic evaluation of N6022: a first-in-class S-nitrosoglutathione reductase inhibitor for the treatment of asthma

S-nitrosoglutathione reductase is the primary enzyme responsible for the metabolism of S-nitrosoglutathione (GSNO), the body's main source of bioavailable nitric oxide. Through its catabolic activity, GSNO reductase (GSNOR) plays a central role in regulating endogenous S-nitrosothiol levels and protein S-nitrosation-based signaling. By inhibiting GSNOR, we aim to increase pulmonary GSNO and induce bronchodilation while reducing inflammation in lung diseases such as asthma. To support the clinical development of N6022, a first-in-class GSNOR inhibitor, a 14-day toxicology study was conducted. Sprague-Dawley rats were given 2, 10 or 50 mg/kg/day N6022 via IV administration. N6022 was well tolerated at all doses and no biologically significant adverse findings were noted in the study up to 10 mg/kg/day. N6022-related study findings were limited to the high dose group. One male rat had mild hepatocellular necrosis with accompanying increases in ALT and AST and several male animals had histological lung assessments with a slight increase in foreign body granulomas. Systemic exposure was greater in males than females and saturation of plasma clearance was observed in both sexes in the high dose group. Liver was identified as the major organ of elimination. Mechanistic studies showed dose-dependent effects on the integrity of a rat hepatoma cell line.

Drug interactions with mitotane by induction of CYP3A4 metabolism in the clinical management of adrenocortical carcinoma

Mitotane [1-(2-chlorophenyl)-1-(4-chlorophenyl)-2,2-dichloroethane, (o,p'-DDD)] is the only drug approved for the treatment for adrenocortical carcinoma (ACC) and has also been used for various forms of glucocorticoid excess. Through still largely unknown mechanisms, mitotane inhibits adrenal steroid synthesis and adrenocortical cell proliferation. Mitotane increases hepatic metabolism of cortisol, and an increased replacement dose of glucocorticoids is standard of care during mitotane treatment. Recently, sunitinib, a multityrosine kinase inhibitor (TKI), has been found to be rapidly metabolized by CYP3A4 during mitotane treatment, indicating clinically relevant drug interactions with mitotane. We here summarize the current evidence concerning mitotane-induced changes in hepatic monooxygenase expression, list drugs potentially affected by mitotane-related CYP3A4 induction and suggest alternatives. For example, using standard doses of macrolide antibiotics is unlikely to reach sufficient plasma levels, making fluoroquinolones in many cases a superior choice. Similarly, statins such as simvastatin are metabolized by CYP3A4, whereas others like pravastatin are not. Importantly, in the past, several clinical trials using cytotoxic drugs but also targeted therapies in ACC yielded disappointing results. This lack of antineoplastic activity may be explained in part by insufficient drug exposure owing to enhanced drug metabolism induced by mitotane. Thus, induction of CYP3A4 by mitotane needs to be considered in the design of future clinical trials in ACC.

Effect of the hepatitis C virus protease inhibitor telaprevir on the pharmacokinetics of amlodipine and atorvastatin

Telaprevir is a hepatitis C virus protease inhibitor that is both a substrate and an inhibitor of CYP3A. Amlodipine and atorvastatin are both substrates of CYP3A and are among the drugs most frequently used by patients with hepatitis C. This study was conducted to examine the effect of telaprevir on atorvastatin and amlodipine pharmacokinetics (PK). This was an open-label, single sequence, nonrandomized study involving 21 healthy male and female volunteers. A coformulation of 5 mg amlodipine and 20 mg atorvastatin was administered on day 1. Telaprevir was taken with food as a 750-mg dose every 8 h from day 11 until day 26, and a single dose of the amlodipine-atorvastatin combination was readministered on day 17. Plasma samples were collected for determination of the PK of telaprevir, amlodipine, atorvastatin, ortho-hydroxy atorvastatin, and para-hydroxy atorvastatin. When administration with telaprevir was compared with administration without telaprevir, the least-square mean ratios (90% confidence limits) for amlodipine were 1.27 (1.21, 1.33) for the maximum drug concentration in serum (C(max)) and 2.79 (2.58, 3.01) for the area under the concentration-time curve from 0 h to infinity (AUC(0-∞)); for atorvastatin, they were 10.6 (8.74, 12.9) for the C(max) and 7.88 (6.84, 9.07) for the AUC(0-∞). Telaprevir significantly increased exposure to amlodipine and atorvastatin, consistent with the inhibitory effect of telaprevir on the CYP3A-mediated metabolism of these agents.

[The composition of blood lipoproteins of donors 2 hours later after single atorvastatin intake]

The distribution of single intake atorvastatin in the content of very low, low and high density lipoproteins extracted from blood plasma of healthy volunteers by means of ultracentrifugal separation was investigated. The impact of atorvastatin on the composition of lipoprotein complexes was assessed. It is demonstrated that atorvastatin and its active derivatives transport mainly in the composition of high density lipoproteins. The distribution of atorvastatin and its biologically active metabolites has gender differences. It is established that in males atorvastatin increases the content of triacylglycerides of low density lipoproteins and cholesterol of high density lipoproteins in females.

Purification and identification of activating enzymes of CS-0777, a selective sphingosine 1-phosphate receptor 1 modulator, in erythrocytes

CS-0777 is a selective sphingosine 1-phosphate (S1P) receptor 1 modulator with potential benefits in the treatment of autoimmune diseases, including multiple sclerosis. CS-0777 is a prodrug that requires phosphorylation to an active S1P analog, similar to the first-in-class S1P receptor modulator FTY720 (fingolimod). We sought to identify the kinase(s) involved in phosphorylation of CS-0777, anticipating sphingosine kinase (SPHK) 1 or 2 as likely candidates. Unlike kinase activity for FTY720, which is found predominantly in platelets, CS-0777 kinase activity was found mainly in red blood cells (RBCs). N,N-Dimethylsphingosine, an inhibitor of SPHK1 and -2, did not inhibit CS-0777 kinase activity. We purified CS-0777 kinase activity from human RBCs by more than 10,000-fold using ammonium sulfate precipitation and successive chromatography steps, and we identified fructosamine 3-kinase (FN3K) and fructosamine 3-kinase-related protein (FN3K-RP) by mass spectrometry. Incubation of human RBC lysates with 1-deoxy-1-morpholinofructose, a competitive inhibitor of FN3K, inhibited ∼10% of the kinase activity, suggesting FN3K-RP is the principal kinase responsible for activation of CS-0777 in blood. Lysates from HEK293 cells overexpressing FN3K or FN3K-RP resulted in phosphorylation of CS-0777 and structurally related molecules but showed little kinase activity for FTY720 and no kinase activity for sphingosine. Substrate preference was highly correlated among FN3K, FN3K-RP, and rat RBC lysates. FN3K and FN3K-RP are known to phosphorylate sugar moieties on glycosylated proteins, but this is the first report that these enzymes can phosphorylate hydrophobic xenobiotics. Identification of the kinases responsible for CS-0777 activation will permit a better understanding of the pharmacokinetics and pharmacodynamics of this promising new drug.

S35972, a direct-acting thrombin inhibitor with high oral bioavailability and antithrombotic efficacy

OBJECTIVES

Dabigatran etexilate is the first oral thrombin inhibitor to demonstrate superior efficacy to warfarin for stroke prevention in patients with atrial fibrillation. This study describes the in vitro, ex vivo anticoagulant and in vivo antithrombotic effects of an oral thrombin inhibitor, S35972, in comparison with dabigatran etexilate.

METHODS

Enzyme assays with thrombin and related serine proteases were performed. Clotting times, including activated partial thromboplastin time (APTT) and thrombin time (TT), were measured in vitro in different species and ex vivo in dogs and rats to determine pharmacologic bioavailabilities. The formation of occlusive venous and arterial thrombi in the rat vena cava and aorta was induced with stasis plus thromboplastin or ferrous chloride, respectively.

RESULTS

 S35972 inhibited human thrombin with an IC(50) of 3.7 nm, and did not inhibit other serine proteases. The anticoagulant activities of S35972 in vitro were comparable in dog and human plasmas, and the sensitivity of the clotting times to S35972 was TT > APTT > prothrombin time. In the fasted dog, oral administration of 3 mg kg(-1) S35972 increased TT rapidly and for at least 8 h, and its pharmacologic bioavailability was 75.4% ± 0.1%. In the rat venous thrombosis model, 3 mg kg(-1) oral S35972 or dabigatran etexilate significantly decreased the thrombus weight. In the rat aortic thrombosis model, oral S35972 at 10mg kg(-1) significantly decreased thrombus weight, by approximately 50%, whereas, at this dose, no effect was obtained with dabigatran etexilate.

CONCLUSIONS

 S35972 is a non-prodrug thrombin inhibitor with high selectivity, oral bioavailability, and antithrombotic efficacy.

Outgrowth of drug-resistant carcinomas expressing markers of tumor aggression after long-term TβRI/II kinase inhibition with LY2109761

TGF-β is produced excessively by many solid tumors and can drive malignant progression through multiple effects on the tumor cell and microenvironment. TGF-β signaling pathway inhibitors have shown efficacy in preclinical models of metastatic cancer. Here, we investigated the effect of systemic LY2109761, a TGF-β type I/II receptor (TβRI/TβRII) kinase inhibitor, in both a tumor allograft model and the mouse skin model of de novo chemically induced carcinogenesis in vivo. Systemic LY2109761 administration disrupted tumor vascular architecture and reduced myofibroblast differentiation of E4 skin carcinoma cells in a tumor allograft. In the 7,12-dimethyl-benzanthracene plus phorbol myristate acetate-induced skin chemical carcinogenesis model, acute dosing of established naive primary carcinomas with LY2109761 (100 mg/kg) every 8 hours for 10 days (100 mg/kg) diminished phospho-Smad2 (P-Smad2) levels and marginally decreased the expression of inflammatory and invasive markers. Sustained exposure to LY2109761 (100 mg/kg/d) throughout the tumor outgrowth phase had no effect on carcinoma latency or incidence. However, molecular analysis of resultant carcinomas by microarray gene expression, Western blotting, and immunohistochemistry suggests that long-term LY2109761 exposure leads to the outgrowth of carcinomas with elevated P-Smad2 levels that do not respond to drug. This is the first description of acquired resistance to a small-molecule inhibitor of the TβRI/TβRII kinase. Resultant carcinomas were more aggressive and inflammatory in nature, with delocalized E-cadherin and elevated expression of Il23a, laminin V, and matrix metalloproteinases. Therefore, TGF-β inhibitors might be clinically useful for applications requiring acute administration, but long-term patient exposure to such drugs should be undertaken with caution.

[Rhabdomyolysis associated with atorvastatin combined with amiodarone and fluconazole]

A 67-year old man was hospitalized due to an aorto-coronary bypass and cecal perforation. After administration of atorvastatin, amiodarone, and fluconazole, rhabdomyolysis developed with electrolyte disturbances (hyperphosphatemia, hyopcalcemia) and a massive increase in creatine kinase and myoglobin. In the clinical course, other complications manifested such as acute renal failure, critical illness myopathy, acute gout on the knee, and sternal infection with coagulase-negative staphylococci. After stopping the assumed causal agents and treating the complications, the patient could be transferred for rehabilitation after a more than two months hospital stay. We discuss the causes and symptoms of muscle diseases as well as the epidemiology, mechanisms, treatment, and prevention of drug-induced myopathies with a focus on statins.

Slow-release formulation of a new biological pesticide, pyoluteorin, with mesoporous silica

A slow-release formula of potential biological pesticide Pyoluteorin (Plt) was prepared by using nanophase material of silicon dioxide loading drugs. The final experimental formula was m(Plt:Brij56:TMOS:HCl(aq)) = 0.04:1.4:2:1, synthesized by a highly ordered monolith (HOM) method. This formula can continuously release 85.13 ± 2.03 % of Plt within 28 days. A characterization study showed the formula formed a well-ordered mesoporous structure, with a surface area of 822 m(2) g(-1), with a measured mesoporous volume of 0.41 cm(3) g(-1) and a narrow distribution for the pore size centered at 2.4 nm. A bioactivity experiment showed it authentically prolonged the antifungal effects. This study is the first to report mesoporous formulations for biological pesticides and indicates a potentially interesting drug carrier. The association of a nanostructured silica to the molecular state of the drug holds great interests for field applications as it overcomes the rapid loss of biological function during drug utilities.

[Association of a polymorphic marker Trp719Arg of KIF6 gene with effects of atorvastatin and simvastatin in patients with early ischemic heart disease]

Action of statins is characterized by pronounced variability what is caused by effects of a multitude of factors. Main of these factors appears to be genetic peculiarity of patients. We studied influence of polymorphic marker Trp719Arg of KIF6 gene on lipid and nonlipid effects of atorvastatin and simvastatin. The studied genetic marker is associated with risk of development of ischemic heart disease and myocardial infarction as well as efficacy of therapy with statins according to data of a number of large multicenter studies. We examined 60 men with ischemic heart disease which had manifested in young age when genetic factors were most expressed and had special significance. Efficacy of 40 mg/day simvastatin did not depend on genotypes of polymorphic marker Trp719Arg of KIF6. Therapy with 10 mg/day atorvastatin was more effective in carriers of polymorphic marker Trp719Arg of KIF6 gene by action on dynamics of changes of high sensitivity C-reactive protein and dispersion of high density lipoprotein response. Increase of atorvastatin dose to 80 mg/day abolished influence of genotypes. Thus for the first time we discovered influence of polymorphic marker Trp719Arg of KIF6 gene on individual response to therapy with 10 mg/day of atorvastatin, while and apoA1, structural protein of high density lipoproteins can be considered as a marker of "fast response".