The dose-dependent effect of chronic Verapamil treatment on cardiac function in isolated rat heart with Hypertension

Funding Acknowledgements

Type of funding sources: None.

Introduction

Verapamil, a calcium channel blocker, is used for treatment of hypertension, paroxysmal supraventricular tachycardia  and angina pectoris. It primarily blocks L-type calcium channels preventing excessive influx of calcium into cardiomyocytes, leading to negative inotropic effect, and smooth muscle cells resulting in reduced relaxation of vasculature. With calcium antagonism it also causes negative chronotropic effect. However, there is no data on it’s dose-dependent effects on cardiac dynamic parameters and heart rate on isolated rat heart with hypertension.

Purpose

To investigate chronic, dose-dependent effects of Verapamil on cardiodynamic parameters in isolated rat heart with hypertension.

Methods

The present 4-week study was carried out on 24 spontaneously hypertensive Wistar Kyoto male rats  (6 weeks old): Control (n = 6), rats treated with 0.5 mg/kg/day of Verapamil (n = 6), rats treated with 5 mg/kg/day of Verapamil (n = 6) and rats treated with 50 mg/kg/day of Verapamil (n = 6). Isolated rat hearts were perfused on Langendorff perfusion apparatus.

Results

Chronic, low-dose Verapamil treatment significantly depressed function of all cardiodynamic parameters of the hypertensive heart when compared to the rats treated with higher doses of Verapamil (p < 0.001), except on the coronary flow and heart rate when compared to the Control (p= 0.137; p = 1.000, respectively). There was no significant differences between Verapamil in middle dose (5 mg/kg/day) and the Control group in inotropic (p = 0.415) and lusitropic (p = 1.000) effects, while it significantly lowered values of coronary flow (p = 0.002). It achieved significantly lower inotropic, lusitropic and chronotropic effects (p < 0.001) than high Verapamil dose and significantly better inotropic (p = 0.017), lusitropic (p < 0.001), but not chronotropic effects than low-dose Verapamil treatment (p = 0.179). High-dose, chronic treatment with Verapamil significantly intensified function of  the isolated rat heart with hypertension when compared to Control and lower doses of Verapamil (p < 0.001), without significant effects on coronary flow (p = 0.363).

Conclusions

Chronic treatment with Verapamil in high dose achieved better inotropic, chronotropic and lusitropic effects than treatment in low and middle doses of Verapamil, without significant effects on coronary flow. There is dose-depended effect of chronic Verapamil treatment on cardiac function of isolated rat heart with hypertension.

P561Acute effects of dronedarone and amiodarone on functional, morphological and oxidative stress parameters in isolated rat heart with hypertension

Introduction

Amiodarone represents the most widely used antiarrhythmic drug, even though it has been shown that it has negative inotropic and lusitropic effect in healthy hears. On the other hand, dronedarone reduces the risk of recurrent atrial fibrillation, but with increased early mortality related to the worsening of heart failure. However, the mechanisms responsible for these fatal outcomes remain unclear and require further examinations. 

Purpose

To investigate acute, direct effects of Dronedarone and Amiodarone on cardiac contractility, coronary flow and oxidative stress parameters in isolated rat heart with hypertension.

Methods

 The present study was carried out on 18 isolated hearts of spontaneously hypertensive Wistar Kyoto male rats (6 weeks old, bodyweight 200 ± 10 g). After isolation, all hearts were retrogradely perfused according to Langendorff technique with a gradually increment of coronary perfusion pressure (CPP from 40 to 120 cm H2O) and randomly divided into 3 groups: Control (n = 6), Amiodarone (n = 6, isolated hearts perfused with Amiodarone in dose of 3 umol), Dronedarone (n = 6, isolated hearts perfused with Dronedarone in dose of 1.8 umol). During ex vivo protocol continuously were registered cardiac contractility parameters and coronary flow, while from collected coronary venous effluent markers of oxidative stress were measured. All hearts were then fixated and stained with Hematoxylin/eosin.

Results

 Dronedarone severely depressed the function of all cardiodynamic parameters of the heart compared with Amiodarone or Control while Amiodarone intensified the function of the isolated rat heart with hypertension compared to Control (dp/dt max mmHg/s at coronary perfusion pressure 120cmH2O Dronedarone vs. Amiodarone vs. Control 579.733 ± 202.27 vs. 3063.65 ± 467.93 vs. 2682.88 ± 368.75; p < 0.001. dp/dt min mmHg/s 120cmH2O -352.13 ± 204.65 vs. 1960 ± 242.21 vs. -1858.83 ± 118.23; p < 0.001. SLVP mmHg at CPP 120cmH20 27.8 ± 3.46 vs. 98.95 ± 11.78 vs. 71.45 ± 7.56; p < 0.001. DLVP mmHg at CPP 120cmH2O 6.32 ± 0.49 vs. 4.83 ± 0.54 vs. 0.85 ± 0.35; p < 0.001). Acute administration of Dronedarone decreased the level of NO2- and increased the level of H2O2 , while Amiodarone heightens O2- levels (O2- nmol/min g wt at coronary perfusion pressure 120cmH2O Dronedarone vs. Amiodarone vs. Control  28.62 ± 2.54 vs. 77.3 ± 8.86 vs. 31.72 ± 4.56; p < 0.001. H2O2 nmol/min g wt at CPP 120cmH2O 92.56 ± 11.65 vs. 48.63 ± 10.11 vs. 42.84 ± 84; p < 0.001. NO2- nmol/min g wt at CPP 120cmH2O 38.61 ± 4.94 vs.  82.28 ± 5.76 vs.  64.71 ± 3.51; p < 0.001). Pathohistological, structural changes were observed in both, experimental groups.

Conclusions

 Acute administration of Dronedarone depresses cardiac function in isolated, working rat heart with hypertension, with decreasing the NO2- levels, increasing the level of H2O2 and enhanced structural changes when compared to Amiodarone.

Pharmacokinetic, Pharmacodynamic, and Activity Evaluation of TMX-101 in a Multicenter Phase 1 Study in Patients With Papillary Non-Muscle-Invasive Bladder Cancer

INTRODUCTION/BACKGROUND

Non-muscle-invasive bladder cancer (NMIBC) has a strong tendency to recur despite adjuvant instillations. TMX-101 is a new liquid form of imiquimod for intravesical instillation and has activity in vitro against urothelial carcinoma. The purpose was to analyze the activity of TMX-101 in low-grade NMIBC. Furthermore, pharmacokinetic and pharmacodynamic characteristics and adverse events were evaluated.

PATIENTS AND METHODS

A multicenter, prospective phase 1 trial in 7 patients with low-grade NMIBC was conducted. All patients underwent a marker lesion transurethral resection of the bladder tumor and 6 weekly instillations with TMX-101 0.2% or 0.4%. Cystoscopy 2 to 4 weeks after the last instillation evaluated the effect of TMX-101.

RESULTS

The effective biologic dose (EBD = complete response [CR] in > 2 patients) could not be defined because none of the patients experienced CR. Maximum plasma concentration was 75.1 ng/mL in the 0.4% dose group. No drug accumulation was observed. In the pharmacodynamic analysis, urinary interleukin 1 receptor agonist (IL-1ra) represents the most sensitive and uniform response after TMX-101 instillation. A total of 87.0% reported at least 1 adverse event. All events were of grade 2 severity or less (Common Terminology Criteria of Adverse Events version 4.02). No clinically significant changes in laboratory parameters or vital signs were observed during or after treatment.

CONCLUSION

Toll-like receptor 7 (TLR-7) agonists are effective in urothelial carcinoma in preclinical research. The EBD in this phase 1 study could not be determined because no patient experienced CR. IL-1ra could be valuable as a urinary biomarker in future developments. The safety of TMX-101 has been reconfirmed. New doses, other schedules, and NMIBC subgroups should be tested to define the EBD. A pilot study in carcinoma-in-situ patients is currently ongoing and results are expected shortly.

Abstract CT341: AFM13: an antigen specific immunotherapy for the treatment of CD30+ malignancies: Results of first-in-man study in relapsed/refractory (R/R) Hodgkin lymphoma (HL)

Introduction: Standard treatment of HL results in high cure rates. However, 30-40% of the patients relapse and 2nd line therapies induce durable remission in only 50% of the patients. AFM13 is a novel, tetravalent bi-specific antibody belonging to Affimed's RECRUIT TandAb platform. AFM13 recruits NK-cells to kill CD30+ tumor cells by targeting CD30 and CD16A. Due to promising pre-clinical data a phase I study was conducted.

Method: Patients with R/R HL that underwent all standard therapy received stepwise escalated doses of i.v. AFM13 from 0.01 to 7.0 mg/kg weekly over 4 weeks (=1 cycle). A small cohort of patients received 4.5 mg/kg of AFM13 twice weekly over 4 weeks. The primary objectives were safety and tolerability, secondary objectives were pharmacokinetics (PK), pharmacodynamics (PD), and efficacy. PD was assessed in plasma and included activated NK cells measured by CD69 expression and soluble CD30 (sCD30). PK was measured after the first infusion for all regimens plus on day 25 (last infusion) for the twice weekly regimen. Tumor response was measured using Cheson criteria 4 weeks after end of treatment.

Results: 24 patients received AFM13 weekly, 5/24 patients received a 2nd cycle. 4 patients were treated twice weekly. AFM13 was well tolerated with mainly mild to moderate adverse events (AEs). The maximum tolerated dose was not reached. One dose limiting toxicity (DLT) was observed in the 0.5 mg/kg cohort: hemolytic anemia CTCAE Grade 4. No further DLTs were observed even at higher doses. The most common AEs were pyrexia (53.6%) and chills (39.3%). 8 patients (26.8%) experienced serious AEs. PK data revealed a dose proportional increase of systemic exposure. AFM13 was detectable in plasma up to 168 h (highest dose) with a half-life of 10-22 hours. AFM13 treatment resulted in an increase of CD69+ NK cells which was more pronounced at doses ≥1.5 mg/kg. The kinetics of NK cell activation correlated with PK. In 24/28 patients sCD30 levels decreased during treatment. All patients receiving ≥1.5 mg/kg of AFM13 had a marked decrease of sCD30. 26/28 patients were eligible for efficacy evaluation. 3 patients had a partial remission (PR), 13 had stable disease (SD) and 10 had disease progression. Overall, the clinical effect was more pronounced in cohorts receiving ≥1.5 mg/kg with an overall response rate of 23% (3/13). Importantly, 6/7 patients who were refractory to most recent brentuximab vedotin therapy achieved SD under AFM13 treatment.

Conclusion: AFM13 was well tolerated and demonstrated activity in terms of PD and tumor response. PK data indicate that the dose regimen has to be optimized and that the measured clinical effect is likely to underestimate the potency of AFM13 in HL. A phase II study with a modified dose regimen is in preparation.

Citation Format: Achim Rothe, Katrin S. Reiners, Max S. Topp, Anas Younes, Bastian von Tresckow, Horst Dieter Hummel, Joerg Kessler, Miroslav Ravic, Jens-Peter Marschner, Elke Pogge von Strandmann, Andreas Engert. AFM13: an antigen specific immunotherapy for the treatment of CD30+ malignancies: Results of first-in-man study in relapsed/refractory (R/R) Hodgkin lymphoma (HL). [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr CT341. doi:10.1158/1538-7445.AM2014-CT341

Abstract 4572: The CD30/CD16A RECRUIT TandAb AFM13 activates patient NK cells resulting in specific tumor cell killing

AFM13 represents a new class of bispecific antibodies, based on the RECRUIT-TandAb platform, which enables the generation of therapeutics with improved efficacy, convenient administration regimens, and excellent safety profiles. AFM13 was developed for the treatment of Hodgkin Lymphoma (HL) and other CD30+ malignancies. AFM13 targets CD30 on HL tumor cells and recruits NK cells via CD16A. Preclinical data demonstrate specific and highly efficient anti-tumor activity by the selectively recruited NK cell immune response, which addresses key deficiencies of monoclonal antibodies: (i) reduced binding to the 158F allotype of CD16A and (ii) non-selective binding to immune effector cells via both activating CD16A and non-signalling CD16B receptors. In vitro assays demonstrate that AFM13 binds with high affinity to both CD30 and CD16A antigens and rapidly induces lysis of CD30+ cells at picomolar concentrations. Further, AFM13 activates CD16A only in the presence of tumor cells: there is no systemic activation of NK-cells in the absence of target cells. A robust GMP process in mammalian cells and a lyophilized formulation with excellent stability are established. Finally, no toxicity is observed in Cynomolgus monkeys. AFM13 was investigated in an open-label single-arm phase I dose escalation trial in heavily pre-treated patients with relapsed/refractory HL. Each patient received 4 weekly doses of AFM13. Seven dose levels from 0.01 to 7.0 mg/kg were escalated in cohorts of 3 patients. In addition, one cohort of 4 patients received AFM13 twice a week at 4.5 mg/kg for 4 weeks. All dose levels of AFM13 proved to be well tolerated and safe and clear signs of anti-tumor activity were demonstrated. We have performed an analysis of the activation of NK cells and clearance of soluble CD30 in humans since these are key parameters for the mode of action of AFM13. We confirmed a correlation between anti-tumor activity parameters and biomarkers based on a statistically significant dose-dependent increase in the activation of NK cells and reduction in soluble CD30 levels. Since the activation of NK cells has been reported to facilitate low-level expression of CD30 on NK cells, which we also observed in several patients in the highest AFM13 dose groups, we investigated whether this may affect NK cell cytotoxicity. Our ex vivo evaluation of samples from patients that received AFM13 and in vitro evaluation of activated NK cells demonstrated no inhibition of NK cell-mediated cytotoxic activity. Furthermore, AFM13 exhibits a remarkable half-life of 1 day which represents a substantial increase relative to that of diabody-like formats currently being evaluated in the clinic for haematological malignancies. Thus, AFM13 has demonstrated encouraging biologic activity and represents a new targeted therapy for heavily pre-treated patients with HL.

Citation Format: Achim Rothe, Max S. Topp, Anas Younes, Uwe Reusch, Stefan Knackmuss, Erich Rajkovic, Dennis A. Eichenauer, Horst Hummel, Katrin S. Reiners, Markus Dietlein, Joerg Kessler, Miroslav Ravic, Christian Hucke, Eugene Zhukovsky, Elke Pogge von Strandmann, Andreas Engert. The CD30/CD16A RECRUIT TandAb AFM13 activates patient NK cells resulting in specific tumor cell killing. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4572. doi:10.1158/1538-7445.AM2013-4572

Results of a phase 1 dose escalation study of intravesical TMX-101 in patients with nonmuscle invasive bladder cancer

PURPOSE

Imiquimod, a toll like receptor 7 (TLR-7) agonist, is effective as a topical treatment for skin malignancies. TMX-101 is a liquid formulation of imiquimod. In this study we establish a safety profile of TMX-101 in patients with nonmuscle invasive bladder cancer.

MATERIALS AND METHODS

We conducted a multicenter phase 1 dose escalation study in patients with nonmuscle invasive bladder cancer. Patients were included in 1 of 4 dose groups (0.05%, 0.1%, 0.2% or 0.4%) and treated with 6 weekly instillations of TMX-101, starting 2 weeks after transurethral resection of bladder tumor. Patients were evaluated weekly, and pharmacokinetic and pharmacodynamic parameters were measured.

RESULTS

A total of 16 patients were included in the study with 4 per dose group. Two patients dropped out after instillation 2 in dose groups 1 and 2. Overall, 88 instillations were administered without serious adverse events. There were 118 adverse events, of which 84 were related to the study drug. All adverse events were mild or moderate and number or severity was not correlated with dose group. Of the related adverse events 70% were confined to the genitourinary tract and resolved without intervention. There was a dose dependent systemic uptake with low plasma levels up to dose group 3 (0.2%, 100 mg). Maximum plasma concentration in dose group 4 (0.4%, 200 mg) was 71.7 ng/ml. This is below plasma concentrations of 123 and 128 ng/ml without significant side effects measured in healthy volunteers after subcutaneous (30 mg) or oral intake (100 mg) of imiquimod, respectively.

CONCLUSIONS

Intravesical treatment with TMX-101 is safe. The side effects are common but mild and mostly limited to the genitourinary tract. There is a low systemic uptake.

Abstract 3521: RECRUIT-TandAb AFM13: Overcoming limitations of monoclonal antibodies in Hodgkin lymphoma

Introduction: AFM13 is a RECRUIT-TandAb (CD30xCD16A) for treating Hodgkin Lymphoma by recruiting NK-cells and macrophages to the specific CD30 surface antigen on Reed-Sternberg cells. This redirected immune response leads to potent tumor cell killing. RECRUIT TandAbs are tetravalent and bispecific, and address key deficiencies of monoclonal antibodies such as (i) V/F polymorphism and (ii) non-selective binding to immune effector cells vs. granulocytes via CD16B receptor. Furthermore, RECRUIT-TandAbs have significant advantages over other antibody fragment technologies such as (i) bivalent binding to the targets and, (ii) longer half-life. Methods: AFM13 binds with high affinity to both CD30 and CD16A and is able to rapidly induce the lysis of CD30+ cells at picomolar concentrations in the presence of PBMCs. Intensive in vitro characterization demonstrated that AFM13 is specific for the CD16A receptor, which becomes activated only in the presence of tumor cells: there is no systemic activation of NK-cells in the absence of target cells. A robust GMP production process in mammalian cells and a lyophilized formulation with excellent stability have been established. Toxicology testing in Cynomolgus monkeys did not reveal any toxicity. Currently, AFM13 is being investigated in a single arm phase I dose escalation trial for patients with relapsed and/or refractory Hodgkin Lymphoma (HL). Patients receive a single cycle of 4 weekly doses, which are escalated in cohorts of 3 patients at the dose levels of 0.01, 0.04, 0.15, 0.5, 1.5, 4.5 and 7.0 mg/kg. Study objectives are the assessment of safety and tolerability, PK, immunogenicity, antitumor activity, as well as the determination of the maximum tolerated dose (MTD) or the optimal biological dose (OBD). The safety of the MTD or OBD will be confirmed in further patients receiving 2 cycles of AFM13. Results and Conclusion: So far, AM13 was shown to be safe and well tolerated by highly pre-treated Hodgkin Lymphoma patients in weekly doses of up to 1.5mg/kg. Adverse events were generally mild, with the most frequent drug-related event being fever. A first objective response was achieved on the dose level 1.5mg/kg. Five cases of stable disease / minor response were observed on lower dose levels. Further patients are being treated in the ongoing dose escalation study. Preclinical and interim clinical data will be presented, showing that AFM13 may become a safe and effective targeted therapy for CD30 positive malignancies.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3521. doi:1538-7445.AM2012-3521

5,6-Dimethylxanthenone-4-acetic acid in the treatment of refractory tumors: a phase I safety study of a vascular disrupting agent

This phase I safety study aimed to identify the optimal dose of the vascular disrupting agent 5,6-dimethylxanthenone-4-acetic acid (DMXAA) for combination studies. Using a crossover design, 15 patients with refractory tumors were allocated randomly to receive six sequential doses of DMXAA (300, 600, 1,200, 1,800, 2,400, and 3,000 mg m(-2)), each given once-weekly as a 20-minute i.v. infusion. The drug was generally well tolerated. Transient, moderate increases in the heart rate-corrected cardiac QT interval occurred at the two highest doses. DMXAA produced transient dose-dependent increases in blood pressure. Transient, dose-related visual disturbances occurred at the two highest doses. No significant changes in K(trans) and k(ep) were observed but V(e), a secondary dynamic contrast-enhanced magnetic resonance imaging variable, increased significantly after giving DMXAA. At 1,200 mg m(-2), the Cmax and the area under the concentration-time curve over 24 hours for total and free DMXAA plasma concentrations were 315 +/- 25.8 microg/mL, 29 +/- 6.4 microg/mL x d, 8.0 +/- 1.77 microg/mL, and 0.43 +/- 0.07 microg/mL x d, respectively. Plasma levels of the vascular damage biomarker 5-hydroxyindoleacetic acid increased in the 4 hours after treatment in a dose-dependent fashion up to 1,200 mg m(-2), with a plateau thereafter. Doses in the range of 1,200 mg m(-2) have been selected for further studies (phase II combination studies with taxanes and platins are under way) because this dose produced no significant effect on heart rate-corrected cardiac QT interval, produced near maximum levels of 5-hydroxyindoleacetic acid, achieved DMXAA plasma concentrations within the preclinical therapeutic range, and was well tolerated.

Effect of rabeprazole and omeprazole on the onset of gastro-oesophageal reflux disease symptom relief during the first seven days of treatment

OBJECTIVE

Gastro-oesophageal reflux disease (GORD) symptoms have a significant impact on patients' well-being. Onset of symptom relief is therefore an important consideration in GORD treatment. The primary objective was to compare the efficacy of rabeprazole (20 mg) and omeprazole (20 mg) regarding onset of heartburn control during the first 7 days of treatment in patients with erosive oesophagitis. Secondary objectives included maintenance of sustained heartburn control, control of other GORD symptoms (e.g. acid regurgitation, epigastric pain, dysphagia), effect on quality of life, patient satisfaction with treatment, and adverse events.

MATERIAL AND METHODS

In this multicentre, randomized, parallel-group, double-blind, comparative study, performed in Europe and Iceland, patients with endoscopically confirmed erosive oesophagitis were randomized to receive once-daily treatment with rabeprazole 20 mg (n=358) or omeprazole 20 mg (n=359) for 7 days. Symptoms were recorded (scored on a 5-point Likert scale) twice daily by the patients on their diary cards.

RESULTS

Median time to reach heartburn control was 1.5 days for both the rabeprazole and omeprazole groups (p<0.43). The results were similar between treatments for other study parameters. Both treatments were well tolerated.

CONCLUSIONS

Unlike previous studies, no significant differences were found between treatments with rabeprazole (20 mg) and omeprazole (20 mg) in this study. Further studies are needed to evaluate the potential benefit of fast-acting proton-pump inhibitors, such as rabeprazole, with respect to onset of symptom control in erosive GORD.

Semi-physiological model describing the hematological toxicity of the anti-cancer agent indisulam

Indisulam (N-(3-chloro-7-indolyl)-1,4-benzenedisulfonamide, GOAL, E7070) is a novel anti-cancer drug currently in phase II clinical development for the treatment of solid tumors. Phase I dose-escalation studies were conducted comparing four treatment schedules. Neutropenia and thrombocytopenia were dose limiting in all schedules. The aim of this study was to describe the extent and the time course of the hematological toxicity and its possible schedule dependency using a semi-physiological model. Data from 142 patients were analyzed using NONMEM. The semi-physiological model comprised a progenitor blood cell compartment, linked to the central circulation compartment, through 3 transition compartments representing the maturation chain in the bone marrow. Plasma concentrations of the drug were assumed to reduce the proliferation rate in the progenitor compartment according to a linear function. A feedback mechanism was included in the model representing the rebound effect of endogenous growth factors. The model was validated using a posterior predictive check. The model adequately described the extent and time course of neutropenia and thrombocytopenia. The mean transition time (MTT, i.e. maturation time in bone marrow) of neutrophils was increased by 47% in patients who received indisulam as a weekly dose administered for four out of every six weeks. For platelets, MTT was increased by 33% in patients who received this schedule and also in patients who received a continuous 120-h infusion. The validation procedure indicated that the model adequately predicts the nadir value of neutrophils and platelets and the time to reach this nadir. A semi-physiological model was successfully applied to describe the time course and extent of the neutropenia and thrombocytopenia after indisulam administration for four treatment schedules.

Phase II study of E7070 in patients with metastatic melanoma

E7070 is a synthetic chloro-indolyl sulphonamide that is being developed as an anti cancer agent. In this phase II study, 28 patients with metastatic melanoma received 700 mg/m(2) of E7070 as a 60-min infusion repeated every 3 weeks. Although therapy was well tolerated, with one patient receiving 14 courses of treatment, there were only minor responses on independent radiological review. E7070 does not warrant further development as a single agent for the treatment of metastatic melanoma.

Repeated dosing with donepezil does not affect the safety, tolerability or pharmacokinetics of single-dose thioridazine in young volunteers

AIM

To investigate the effects of donepezil at steady state on the safety, tolerability and pharmacokinetics of a single dose of thioridazine, in healthy subjects.

METHODS

An open, two-way, balanced crossover study, in 12 subjects (six men and six women) aged 19-41 years. During both treatment periods, subjects received a single oral dose of 50 mg thioridazine; in one period the thioridazine was given alone, and in the other period it was given together with the last of 15 daily, oral doses of donepezil 5 mg. The 'washout' periods were 1 week when thioridazine was given first, and 2 weeks when thioridazine was given last. Plasma concentrations of thioridazine were measured after each dose, and pharmacokinetic parameters were determined. Interactions were tested by using an equivalence analysis in which thioridazine was the 'Reference' and thioridazine + donepezil the 'Test' regimen. Safety and tolerability were monitored.

RESULTS

Donepezil had no marked effect on the pharmacokinetics of thioridazine, as judged by the equivalence analysis of AUC(0-tn), AUC(0-infinity), t((1/2)) and t(max). C(max) was very similar in the 'Test' and 'Reference' regimens, but the confidence intervals were too wide to confirm equivalence. Donepezil was well tolerated, whereas thioridazine was associated with light-headedness, tiredness and postural hypotension, irrespective of whether or not donepezil was given concurrently.

CONCLUSIONS

Repeated dosing with donepezil, 5 mg daily for 2 weeks, had no significant effect on the safety, tolerability or pharmacokinetics of thioridazine. Thioridazine was poorly tolerated.

Phase I and pharmacokinetic study of E7070, a chloroindolyl-sulfonamide anticancer agent, administered on a weekly schedule to patients with solid tumors

PURPOSE

E7070 is a sulfonamide that induces arrest at the G(1)-S boundary with subsequent dose and exposure-dependent apoptosis. The objectives of this study were (a) to determine the maximum-tolerated dose (MTD) and recommended safe dose (RD) of E7070 for additional evaluation, (b) to define the dose limiting toxicity(ies) [DLT(s)], (c) to study the pharmacokinetics of E7070, and (d) to seek preliminary evidence of antitumor activity.

EXPERIMENTAL DESIGN

Patients with solid tumors who had either failed or were not amenable to established forms of treatment were eligible for the study. E7070 was administered i.v. at weekly intervals for 4 consecutive weeks to cohorts of 3-6 patients at each dose level. Treatment was repeated six weekly in the absence of tumor progression. A Fibonacci-like scheme was used for dose escalation. The MTD was determined in a stepwise procedure for two cohorts of patients; the "initial patient cohort" who met the original inclusion criteria (group A) and the "better prognosis cohort" (group B) who had adequate hepatic function, less extensive tumor involvement of the liver, and no more than three previous lines of chemotherapy. The RD was defined as the highest dose at which the incidence of definitely drug-related DLTs was <33%. The pharmacokinetic profile of E7070 was determined.

RESULTS

Overall, 46 patients entered the study; information from 36 of the 37 patients forming group A was used to determine the overall MTD. An additional 9 patients plus 9 patients from group A who met the more restrictive inclusion criteria made up group B. The MTD was 500 mg/m(2)/week for both groups. Reversible neutropenia and thrombocytopenia were the most common DLTs. Other DLTs included stomatitis, hyperglycemia, sepsis, fever, hemorrhage, diarrhea, nausea, and fatigue. The pharmacokinetics of E7070 were nonlinear over the dose range 160-500 mg/m(2). One partial response was observed in a patient with an endometrial adenocarcinoma who had previously been treated with radiotherapy. Twelve other patients had stable disease as their best response (27%); among them. 1 patient with metastatic melanoma who received 21 cycles of therapy.

CONCLUSIONS

The RD for further study of E7070 using this administration schedule is 400 mg/m(2)/week. Using this schedule, the predominant toxicity of E7070 is myelosuppression. E7070 has anticancer activity in pretreated patients.

In vitro pharmacokinetic study of the novel anticancer agent E7070: red blood cell and plasma protein binding in human blood

E7070 is a novel sulfonamide anticancer agent that arrests the G(1)/S phase of the cell cycle. Preclinical and phase I studies have demonstrated non-linear pharmacokinetics (PK) of the drug. A population PK analysis revealed that the human plasma concentration-time data were best described by a three-compartment model with non-linear distribution. We have studied the in vitro interaction of 14C-radiolabeled E7070 with red blood cells (RBC) and its binding to plasma proteins in the concentration range where non-linearity in disposition was observed in humans to get more insight into the behavior of the drug. After the addition of E7070 to whole blood at 37 degrees C, the drug is taken up or binds to RBC in a concentration-dependent manner. The addition of sodium azide, however, did not result in a decrease of drug uptake by RBC, indicating passive diffusion processes. A non-linear increase in drug uptake was observed at incubation concentrations above 4 microg/ml E7070 in whole blood. This non-linearity was confirmed by lower partition coefficients between RBC and plasma at higher incubation concentrations (from 2.37 at 4 microg/ml to 0.31 at 200 microg/ml). The plasma protein binding of E7070 was high (98-99%) and linear in the concentration range studied (20-200 microg/ml). In conclusion, E7070 in whole blood is preferentially bound to RBC and exhibits high plasma protein binding. The non-linear distribution of E7070 in humans can be caused, in part at least, by saturable binding of E7070 to RBC.

Acid inhibition on the first day of dosing: comparison of four proton pump inhibitors

BACKGROUND

Rapid and consistent acid suppression on the first day of dosing may be important in treating acid-related disorders.

AIM

To compare the antisecretory activity and onset of action of single doses of rabeprazole, lansoprazole, pantoprazole, omeprazole capsule, omeprazole multiple unit pellet system (MUPS) tablet and placebo in healthy Helicobacter pylori-negative subjects.

METHODS

This cross-over, double-blind, randomized study was performed in 18 H. pylori-negative subjects. Twenty-four-hour intragastric pH monitoring was performed on the day of treatment (once-daily dose of rabeprazole 20 mg, lansoprazole 30 mg, pantoprazole 40 mg, omeprazole capsule 20 mg, omeprazole MUPS tablet 20 mg or placebo).

RESULTS

The intragastric pH (3.4) and time at pH > 4 during the 24 h post-dose (8.0 h) were significantly greater with rabeprazole than with lansoprazole, pantoprazole, omeprazole capsule, omeprazole MUPS tablet or placebo (P <or= 0.04 for rabeprazole vs. the others). Daytime and night-time pH values were higher with rabeprazole and lansoprazole than with pantoprazole, omeprazole capsule and omeprazole MUPS tablet (P </= 0.04).

CONCLUSION

Rabeprazole was the most potent acid inhibitor of all the proton pump inhibitors tested during the first day of dosing.

Phase I clinical and pharmacokinetic study of E7070, a novel sulfonamide given as a 5-day continuous infusion repeated every 3 weeks in patients with solid tumours. A study by the EORTC Early Clinical Study Group (ECSG)

A single-agent dose-escalating phase I study on the novel sulfonamide E7070 was performed to determine the toxicity profile and the recommended dose for phase II studies. The pharmacokinetic profile of E7070 was also determined. E7070 was administered as a continuous infusion over 5 days repeated every 3 weeks. 27 patients were treated at doses ranging from 6 to 200 mg/m(2)/day. As with other administration schedules, the dose-limiting toxicities were dose-dependent, reversible neutropenia and thrombocytopenia. Although no objective responses were observed, seven patients had stable disease. E7070 displayed a non-linear pharmacokinetic profile, especially at dose-levels greater than 24 mg/m(2)/day, with a reduction in clearance and an increase in the half-life at the higher dose levels. The risk of myelosuppression became significant with an AUC greater than 4000 microg h/ml. The recommended dose of E7070 for further studies is 96 mg/m(2)/day when administered on a 5-day continuous infusion schedule every 3 weeks.

Safety and efficacy of 7-day rabeprazole- and omeprazole-based triple therapy regimens for the eradication of Helicobacter pylori in patients with documented peptic ulcer disease

AIM

A double-blind, randomized study was designed to determine whether rabeprazole- and omeprazole-based triple therapy regimens are therapeutically equivalent in the eradication of Helicobacter pylori.

METHODS

Three hundred and forty-five patients with current or previously active peptic ulcer and a positive H. pylori urease test were randomly assigned to receive RCA, OCA, RCM or OCM twice daily for 7 days (R, rabeprazole 20 mg; O, omeprazole 20 mg; C, clarithromycin 500 mg; A, amoxicillin 1000 mg; M, metronidazole 400 mg). H. pylori eradication was documented by negative 13C-urea breath tests at 4 and 12 weeks, and was evaluated using a 2 x 2 factorial design with proton pump inhibitor and antibiotic as factors.

RESULTS

Overall eradication rates (per protocol/intention-to-treat) were 87%/77% and 85%/75% with rabeprazole and omeprazole, respectively (not significant). However, a statistical interaction between proton pump inhibitor and antibiotic was identified. RCA produced a somewhat higher eradication rate than OCA (94% vs. 84%; difference, 9.8%; 95% confidence interval, - 0.7% to + 20.4%), whereas RCM produced a lower eradication rate than OCM (79% vs. 86%; difference, 8.1%; 95% confidence interval, - 21.4% to + 5.1%). Ulcer healing rates were > 90% with H. pylori eradication. Each regimen was well tolerated.

CONCLUSIONS

Rabeprazole- and omeprazole-based triple therapy regimens are therapeutically equivalent in the eradication of H. pylori and well tolerated. The statistical interaction observed between the proton pump inhibitor and supplementary antibiotic may be due to chance.

Development and validation of limited sampling strategies for prediction of the systemic exposure to the novel anticancer agent E7070 (N-(3-chloro-7-indolyl)-1,4-benzenedisulphonamide)

AIMS

E7070 is a novel, sulphonamide anticancer agent currently under clinical development for the treatment of solid tumours. The aim of this study was to develop and validate limited sampling strategies for the prediction of E7070 exposure in two different treatment schedules for phase II studies using the Bayesian estimation approach.

METHODS

Data from two phase I dose finding studies were used in which E7070 was administered either as a single 1 h infusion or as a daily 1 h infusion for 5 days. Plasma concentration-time data from 75 patients were randomly divided into an index data set, used for the development of the strategies, and a validation data set. Population pharmacokinetic parameters were derived on the basis of the index data set. The D-optimality algorithm was used for the selection of optimal time points for both treatment schedules. The developed strategies were compared by assessment of their predictive performance of exposure, expressed as AUC (area under the plasma concentration vs time curve), in the validation data set.

RESULTS

The developed population pharmacokinetic model comprised three compartments, with saturable distribution to one peripheral compartment and both linear and saturable elimination from the central compartment. For the 1 h infusion, a four sample strategy was selected which resulted in unbiased and accurate predictions of AUC (bias 0.74%, precision 13%). A five sample strategy was generated for the daily times five schedule yielding unbiased (bias 3.2%) and precise (12% precision) predictions of AUC.

CONCLUSIONS

Optimal sampling strategies were developed and validated for estimation of E7070 exposure in two different treatment schedules. Both schedules enabled accurate and unbiased predictions of AUC.

Population pharmacokinetics of the novel anticancer agent E7070 during four phase I studies: model building and validation

PURPOSE

N-(3-Chloro-7-indolyl)-1,4-benzenedisulfonamide (E7070) is a novel sulfonamide anticancer agent currently in phase II clinical development for the treatment of solid tumors. Four phase I studies have been finalized, with E7070 administered at four different treatment schedules to identify the maximum-tolerated dose and the dose-limiting toxicities. Pharmacokinetic analyses of all studies revealed E7070 to have nonlinear pharmacokinetics. A population pharmacokinetic model was designed and validated to describe the pharmacokinetics of E7070 at all four treatment schedules and to identify the possible influences of patient characteristics on the pharmacokinetic parameters.

PATIENTS AND METHODS

Plasma concentration-time data of all patients (n = 143) were fitted to several pharmacokinetic models using NONMEM. Seventeen covariables were investigated for their relation with individual pharmacokinetic parameters. A bootstrap procedure was performed to check the validity of the model.

RESULTS

The data were best described using a three-compartment model with nonlinear distribution to a peripheral compartment and two parallel pathways of elimination from the central compartment: a linear and a saturable pathway. Body-surface area (BSA) was significantly correlated to both the volume of distribution of the central compartment and to the maximal elimination capacity. The fits of 500 bootstrap replicates of the data set demonstrated the robustness of the developed population pharmacokinetic model.

CONCLUSION

A population pharmacokinetic model has been designed and validated that accurately describes the data of four phase I studies with E7070. Furthermore, it has been demonstrated that BSA-guided dosing for E7070 is important.

An excretion balance and pharmacokinetic study of the novel anticancer agent E7070 in cancer patients

E7070 is a novel sulfonamide anticancer agent that arrests the G /S phase of the cell cycle. Preclinical and phase I studies have demonstrated non-linear pharmacokinetics of the drug. The objective of this study was to quantify the excretion of E7070 and the metabolite 1,4-benzene-sulfonamide (M1) in cancer patients. E7070 (1,000 mg) radiolabeled by (14)C in the benzene disulfonamide moiety (cohort 1, n = 6) or in the indole moiety (cohort 2, n = 7) was i.v. infused over 1 h. The levels of radioactivity in plasma, red blood cells, urine and feces were determined by liquid scintillation counting, and the E7070 and M1 concentrations in plasma, urine and feces were determined by coupled liquid chromatography-tandem mass spectrometry (LC/ESI-MS/MS). In plasma, the mean area under the concentration-time curve (AUC) based on radio-activity measurements (32.5 and 28.9 h. mM in cohorts 1 and 2, respectively) was substantially higher than the mean AUC of E7070 (3.8 h x mmol/l) and M1 (0.1 h x mmol/l) in all patients. The excretion of radioactivity (mean +/- SD) as a percentage of administered radioactivity was higher in urine [63.7 +/- 9.8% (cohort 1) and 61.5 +/- 5.5% (cohort 2)] than in feces [22.7 +/- 2.6% (1) and 21.1 +/- 3.1% (2)] during a mean collection period of 11 days. In both cohorts, the contribution of urinary and fecal recovery of E7070 (2.3 and 2.7%, respectively) and M1 (5.3 and 5.1%, respectively) was low. Subsequent HPLC analysis with online radioisotope detection of urine showed that the high radioactivity levels are caused by compounds other than E7070 and M1. The major metabolite is formed by glucuronidation of a hydroxylated metabolite of E7070. In conclusion, the excretion of the benzene sulfonamide and the indole moieties of E7070 was the same with a higher renal than gastrointestinal excretion. E7070 is extensively converted into currently unidentified metabolites. Glucuronidation is a major metabolic pathway.

Phase I and pharmacokinetic study of E7070, a novel chloroindolyl sulfonamide cell-cycle inhibitor, administered as a one-hour infusion every three weeks in patients with advanced cancer

PURPOSE

The objectives were to determine the maximum-tolerated dose, the recommended dose, the dose-limiting toxicity, the pharmacokinetics, and the activity of E7070, a novel cell-cycle inhibitor.

PATIENTS AND METHODS

E7070 was given as a 1-hour intravenous infusion every 3 weeks in two groups of patients with advanced solid tumors who met prespecified eligibility criteria (group A) or who met the same eligibility criteria but in addition were less heavily pretreated and had more favorable liver functions (group B).

RESULTS

Forty patients (31 patients in group A and nine patients in group B) were entered. Dose escalation proceeded through eight levels (range, 50 to 1,000 mg/m(2)). In group A, neutropenia and thrombocytopenia were dose-limiting toxicities occurring during the first cycle in two of seven patients treated at the doses of 700 mg/m(2) and two of four patients treated at 800 mg/m(2). Identical dose-limiting toxicities were observed in zero of six and two of three patients from group B at doses of 800 and 1,000 mg/m(2), respectively. Other toxicities included acne-like skin eruption, mucositis, conjunctivitis, nausea, fatigue, and alopecia. At doses greater than 400 mg/m(2), the area under the concentration-time curve increased disproportionately to the administered dose. Tumor stabilization lasting > or = 6 months was observed in six assessable patients.

CONCLUSION

The recommended doses of E7070 in this schedule were 700 mg/m(2) (group A) and 800 mg/m(2) in patients who were less heavily pretreated (group B) with a moderate tumor burden. Prolonged disease stabilization observed in this study might warrant further investigation of E7070 in selected tumor types.

Phase I and pharmacokinetic study of E7070, a novel sulfonamide, given at a daily times five schedule in patients with solid tumors. A study by the EORTC-early clinical studies group (ECSG)

BACKGROUND

E7070 is a novel antitumor sulfonamide which blocks the cell in G1 phase. A phase I study was initiated to investigate the toxicity, maximum tolerated dose (MTD), and pharmacokinetics of this compound when administered intravenously at a daily times five schedule once every three weeks.

PATIENTS AND METHODS

Patients with solid tumors not amenable to standard forms of therapy were eligible. E7070 was administered to cohorts of 3-6 patients per dose level, the starting dose was 10 mg/m2/day. Dose escalation was performed according to a Fibonacci-like scheme.

RESULTS

Thirty-three patients entered the study. At E7070 doses of 200 and 160 mg/m2/day dose-limiting toxicities occurred, which consisted of febrile neutropenia, thrombocytopenia. diarrhea, skin folliculitis, asthenia, and stomatitis. The pharmacokinetic profile of E7070 at this schedule is non-linear with increasing dose. A partial response was observed in a patient with heavily pretreated breast cancer. Disease stabilizations and some minor responses were also documented.

CONCLUSIONS

Myelosuppression is the predominant toxicity of E7070. Clinical efficacy with E7070 was observed. The recommended dose for further studies at this daily times five schedule is 130 mg/m2/day.

A pharmacokinetic interaction between cimetidine or ranitidine and lornoxicam

Cimetidine 400 mg twice daily significantly increased serum concentrations and reduced apparent oral clearance of lornoxicam 8 mg twice daily in 12 healthy volunteers. Ranitidine 150 mg twice daily produced no significant changes in lornoxicam pharmacokinetics.

Renal and general tolerability of repeated doses of nimesulide in normal subjects

The renal and general tolerability of nimesulide was studied in 16 healthy men, randomised to 4 groups of 4 subjects. The groups all underwent 2 treatment periods of 7 days each, separated by a washout period of 14 days. The second treatment period was always at a higher dosage level than the first. There were 4 dosage regimens: placebo, and nimesulide 200, 300 and 400mg, all given twice daily by mouth according to a double-blind design. The tolerability of nimesulide was assessed by regular clinical examination, nondirected questions about adverse events, haematological and biochemical screening, and daily urine testing. Plasma and urinary concentrations of Tamm-Horsfall glycoprotein (THG), urinary retinol-binding protein (RBP) and beta-N-acetyl glucosaminidase (NAG) on days 1, 3, 7, and 10 of each period were used as selective indicators of nephrotoxicity. The highest dose of nimesulide (800mg daily) was associated with abdominal pain and indigestion in 5 of 8 recipients. The 400 and 600mg daily dosages were well tolerated. There were no clinically significant alterations in the haematological or biochemical screening tests during the study, and daily urinalysis remained normal throughout. The renal toxicity tests showed no evidence of nephrotoxicity associated with the administration of nimesulide in 14 subjects. The other 2 subjects each had modest increases in either urinary THG or NAG concentrations during treatment with nimesulide 800mg daily, but the results of their other tests remained normal. The study, therefore, showed only equivocal evidence of minor renal toxicity with nimesulide 800mg daily. Nimesulide 400 and 600mg daily were well tolerated in all respects, even though these dosages are higher than those recommended for clinical use.

The effect of repeated oral doses of lornoxicam on antipyrine elimination in normal human volunteers

Treatment with lornoxicam 4 mg twice daily for 14 d did not produce any change in salivary antipyrine elimination in 11 of 12 healthy volunteers. Anomalous results in one subject are presented and discussed.