[Importance of Post-Marketing Studies in Gathering of Clinical Evidences for Proper Usage of Anti-Cancer Drugs, and the StudyRequirements for Their Credibility].

Pharmaceutical companies recognize the importance of post-marketing studies because they are crucial in the generation of clinical evidences for the usage of new medicines. To generate clinical evidences, quality of post-marketing studies should be well controlled from view point of "ethical conduction" and "reliability of results". In addition, control of conflict of interest (COI) between researchers and industries is also indispensable and is requested for the transparency of the studies. Japan Pharmaceutical Manufacturers Association(JPMA)stresses its commitment to the progressof transparency in post-marketing studies.

[Expectation for the drug development activity in academia].

Recently many pharmaceutical industries aim at "academic-industrial alliances" to increase opportunities for new drug development. The form of the alliance is mainly a "center-based" one, but recently "open-type" alliance has also become popular. To promote effective collaboration between academia and industries, both parties should obtain clear understanding and support from society through compliance with the social requirement including accountability on the collaborative research and transparency on their relationship. In addition, clinical studies need to comply with the "Ethical Guideline for Clinical Research," or Good Clinical Practice (GCP). Pharmaceutical industries anticipate seeing the deliverables of academic research, and are working on realization of utilizing them in actual medicinal cases.

Comparison between YM099 and captopril in rats with renal mass reduction-induced progressive renal disease.

The effects of the ATP-sensitive potassium (KATP) channel opener YM099, and the angiotensin-converting enzyme (ACE) inhibitor captopril, on the progression of renal disease in rats with surgical renal mass reduction (RMR) were evaluated. Rats were subtotal (5/6) nephrectomized by resection of the renal poles. After 2 weeks of RMR, rats were randomized to three groups and treated for 6 weeks: no treatment (n=9); YM099 at a dose of 0.3 mg/kg by daily oral administration (n=9); or captopril at a dose of 50 mg/kg by daily oral administration (n=9). Sham-operated rats were used as normal animals (n=9). In RMR rats with no treatment, proteinuria progressively developed. At 8 weeks after RMR, renal function as assessed by plasma creatinine (Pcr) and blood urea nitrogen (BUN) was impaired. Pharmacological activation of KATP channel opening by YM099 showed no beneficial effect on proteinuria and renal functional parameters. On the other hand, pharmacological ACE inhibition by captopril significantly attenuated proteinuria, and tended to inhibit the increases in Pcr and BUN; however, these effects were not statistically significant. The presents study indicates that YM099 exhibits no renoprotection with antiproteinuric effect in rats with progressive renal disease. These findings suggest that activation of KATP channel opening may play no role in the retardation of progressive renal disease.

Antithrombotic and thrombolytic efficacy of YM-254890, a G q/11 inhibitor, in a rat model of arterial thrombosis.

We examined the antithrombotic and thrombolytic effects of the G(q/11) inhibitor YM-254890 in an electrically-induced carotid artery thrombosis model in rats. YM-254890 dose-dependently inhibited ex vivo ADP-induced platelet aggregation after i.v. bolus injection. In the thrombosis study, YM-254890 dosedependently prolonged time to occlusion at doses of 3 and 10 g/kg i.v. and decreased occlusion rate at 10 g/kg i.v. In the thrombolysis study, YM-254890 at 30 micro g/kg i.v. shortened the time to reperfusion and prevented reocclusion after thrombolysis with a modified tissue-type plasminogen activator. YM-254890, at 10 micro g/kg and more, significantly improved carotid patency status after thrombolysis. However, at 30 micro g/kg and more, YM-254890 decreased systemic blood pressure. These results suggest that YM-254890 may be effective for treating G(q)-mediated diseases, and that YM-254890 is a useful tool for investigating the biological roles of G(q/11).

YM-53601, a novel squalene synthase inhibitor, suppresses lipogenic biosynthesis and lipid secretion in rodents.

1. To better understand how it decreases plasma cholesterol and triglyceride levels, we evaluated the effect of (E)-2-[2-fluoro-2-(quinuclidin-3-ylidene)ethoxy]-9H-carbazole monohydrochloride(YM-53601) on lipogenic biosynthesis in the liver and lipid secretion from the liver in rats and hamsters. 2. Single administration of YM-53601 in cholestyramine-treated rats inhibited triglyceride and free fatty acid (FFA) biosynthesis at a similar dose range to that at which it inhibited cholesterol biosynthesis. YM-53601 inhibited both triglyceride and FFA biosynthesis in hamsters treated with cholestyramine. 3. YM-53601 by single oral administration decreased the enhanced plasma triglyceride levels in hamsters induced by an injection of protamine sulfate, which inhibits lipoprotein lipase (LPL) and consequently increases plasma very low-density lipoprotein (VLDL) triglyceride levels. YM-53601 also decreased the enhanced plasma triglyceride and cholesterol levels in hamsters treated with Triton WR1339, which also inhibits the degradation of VLDL. Plasma cholesterol was significantly decreased as soon as 1 h after single administration of YM-53601 in hamsters fed a normal diet. 4. This is the first report that a squalene synthase inhibitor suppresses lipogenic biosynthesis in the liver and cholesterol and triglyceride secretion from the liver in vivo. We therefore suggest that the mechanism by which YM-53601 decreases plasma triglyceride might include these effects. The finding that YM-53601 rapidly decreased plasma cholesterol suggests that this compound may be effective in decreasing plasma cholesterol levels early in the course of treatment of hypercholesterolemia in humans.

Preventive effect of zelandopam, a dopamine D1 receptor agonist, on cisplatin-induced acute renal failure in rats.

To elucidate the role of peripheral dopamine D1 receptors in cisplatin-induced acute renal injury, effect of zelandopam (YM435, (-)-(S)-4-(3,4-dihydroxyphenyl)-7,8-dihydroxy-1,2,3,4-tetrahydroisoquinoline hydrochloride hydrate), a selective renal dopamine D1 receptor agonist, on cisplatin-induced acute renal failure in rats was studied. Rats were divided into six groups: control, cisplatin and cisplatin plus zelandopam (30, 100, 300 mg/kg p.o. twice, 75 and 15 min before cisplatin injection) or the free radical scavenger CV-3611 (2-O-octadecylascorbic acid, 10 mg/kg p.o., 75 min before cisplatin injection) treated groups. Rats received intraperitoneal injection of cisplatin at a dose of 5 mg/kg. Four days after cisplatin injection, plasma creatinine, blood urea nitrogen and body weight were measured and the kidneys were removed for histological examination. Cisplatin induced acute renal failure characterized by the increases in plasma creatinine and blood urea nitrogen with tubular damage, and decreased body weight. Zelandopam dose-dependently prevented all these changes. The free radical scavenger CV-3611 significantly attenuated a decrease in body weight and renal dysfunction without reducing tubular damage. The present study is the first demonstration for that a selective dopamine D1 receptor agonist is effective in preventing acute renal failure induced by cisplatin.

Progression of renal failure with anaemia and multiple effects of angiotensin-converting enzyme inhibitor in rats with renal mass reduction.

Several factors such as proteinuria and renal fibrosis may be important in the progression of many forms of chronic renal diseases. The purposes of the current study were to investigate the progressive renal failure of the rats with surgical renal mass reduction (RMR) and the effect of the angiotensin-converting enzyme (ACE) inhibitor, lisinopril, and to document correlation of several factors associated with progressive renal failure. Rats were subtotal (5/6) nephrectomized by resection of the renal poles and sham-operated. The functional, histological and haematological changes of the rats were studied for up to 10 weeks. After 2 weeks of RMR, oral administration of lisinopril (10 mg kg(-1) per day) was performed for 8 weeks. RMR resulted in progressive renal failure with proteinuria, monocyte/macrophage (ED1+) infiltration, anaemia as assessed by haemoglobin and haematocrit (Htc), renal hypertrophy as assessed by left kidney to body weight ratio (BKW/BW), and renal fibrosis as assessed by glomerular lesions and tubulointerstitial changes. Lisinopril exhibited renoprotection with antiproteinuric effect and inhibition of monocyte/macrophage (ED1+) infiltration. However, beneficial effect of lisinopril on anaemia was not observed. At 10 weeks after surgery, severity of proteinuria positively correlated with plasma creatinine (Pcr), BKW/BW, histological damage, and systolic blood pressure, and negatively correlated with haemoglobin. Severity of tubulointerstitial changes positively correlated with Pcr and blood urea nitrogen, and negatively correlated with haemoglobin and Htc. Moreover, monocyte/macrophage (ED1+) infiltration positively correlated with severity of proteinuria and tubulointerstitial changes. These findings strongly support that proteinuria, monocyte/macrophage infiltration and renal fibrosis appear to play principal roles in the progressive renal failure with anaemia and renoprotection of ACE inhibition may be mediated by multiple actions of ACE inhibitor. The present study confirms that rats with RMR is useful to explore target molecules for renoprotective drugs and evaluate renoprotective effect of new molecular entities.

Effect of YM-53601, a novel squalene synthase inhibitor, on the clearance rate of plasma LDL and VLDL in hamsters.

1. To better understand how it decreases plasma cholesterol and triglyceride, we evaluated the effect of YM-53601 ((E-2-[2-fluoro-2-(quinuclidin-3-ylidene) ethoxy]-9H-carbozole monohydrochloride) on the clearance rate of low density lipoprotein (LDL) and very low density lipoprotein (VLDL) in hamsters. 2. Treatment with YM-53601 at 50 mg kg(-1) for 5 days in hamsters fed a normal diet enhanced the disappearance of 1,1'-Dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (DiI)-VLDL and DiI-LDL. This effect on DiI-LDL was lost in the early phase after DiI-methyl(met)-LDL, chemically modified to block LDL receptor binding, was injected in hamsters, but was retained in the late phase. Pre-treatment with protamine sulphate, which inhibits the activity of LPL, also failed to enhance DiI-VLDL clearance rate by YM-53601. 3. Even on single oral administration at 30 mg kg(-1), YM-53601 enhanced the disappearance of the high concentration of plasma triglyceride after injection of intrafat, an emulsion of fat. Plasma triglyceride was significantly decreased as soon as 1 h after single administration of YM-53601 in hamsters fed a normal diet. 4. These results indicate that the decrease in plasma total cholesterol and triglyceride after the treatment with YM-53601 is due to its enhancement of the clearance rate of LDL and VLDL, respectively. Moreover, YM-53601 may be effective in decreasing plasma triglyceride levels early in the course of treatment of hypertriglyceridaemia in humans.

Effects of angiotensin II type 1 receptor antagonist, YM358, on cardiac hypertrophy and dysfunction after myocardial infarction in rats.

This study was undertaken to investigate the effects of an angiotensin II type 1 receptor antagonist, YM358 (2,7-diethyl-5-[[2'(1H-tetrazol-5-yl)biphenyl-4-yl]methyl]-5H-pyrazolo [1,5-b] [1,2,4]triazole potassium salt monohydrate), on cardiac hypertrophy and dysfunction in rats with heart failure after myocardial infarction (MI). One day after the coronary ligation, rats were randomized, and administered YM358 or vehicle for 2, 4 or 8 weeks. In MI rats, mean blood pressure, left ventricular (LV) systolic pressure, and the first derivative of LV pressure significantly decreased, and LV end-diastolic pressure (LVEDP) markedly increased after 2 to 8 week treatment of YM358. From 2 weeks after the ligation, ratios of cardiac weight and lung weight to body weight (BW) significantly increased, which indicated the progression of cardiac hypertrophy and lung congestion in MI rats. Two weeks after the ligation, YM358 did not improve LV function, although it decreased the elevated LVEDP and cardiac weights/BW ratios 8 weeks after the ligation. These results indicated that long-term treatment with YM358 improves the reduced cardiac function and reduces cardiac hypertrophy after MI, and may be useful for the treatment of congestive heart failure.

Pharmacological properties of YM-57029, a novel platelet glycoprotein IIb/IIIa antagonist.

The pharmacological properties of YM-57029 [4-[4-(4-carbamimidoylphenyl)-3-oxopiperazin-1-yl]piperidino]acetic acid monohydrochloride trihydrate), a novel glycoprotein IIb/IIIa antagonist were examined in this study. YM-57029 inhibited fibrinogen binding to purified glycoprotein IIb/IIIa, 1000-fold more potently than the tetrapeptide arginine-glycine-aspartic acid-serine (RGDS). YM-57029 concentration-dependently inhibited ADP-, collagen- and high shear stress-induced platelet aggregation, strongly inhibited ATP release from platelets activated by ADP, and enhanced deaggregation of ADP-induced platelet aggregates. In a pro-aggregatory activity study, RGDS or SC-54701A ((S)-3-[3-[(4-amidinophenyl)carbamoyl]propionamido]-4-pentynoic acid monohydrochloride) caused prominent small aggregate formation. At a higher concentration, RGDS induced medium and large size aggregates, and SC-54701A induced medium aggregates. In contrast, YM-57029 produced only a few small and no larger size aggregates. Ex vivo ADP-induced platelet aggregation and platelet retention to collagen-coated plastic beads were dose-dependently inhibited by YM-57029 after intravenous bolus injection in guinea pigs. YM-57029 produced dose-dependent antithrombotic effects in carotid artery thrombosis and arterio-venous shunt thrombosis models in guinea pigs at 10 and 30 microg/kg, respectively. At these doses, YM-57029 prolonged template bleeding time. These results suggest that YM-57029 is a potent glycoprotein IIb/IIIa antagonist which has less pro-aggregatory effect. It may be a promising antiplatelet agent for thromboembolic diseases, and a good prototype for developing an orally active compound.