First-in-human dose: current status review for better future perspectives.

AIM: The aim of this article is to understand the pros and cons of various methods involved in first-in-human (FIH) dose calculation and act decisively in dose escalations when calculating the maximum tolerated dose. SUBJECTS AND METHODS: We reviewed early phase clinical trials for methods of FIH dose and dose-escalation steps and discuss them in line with existing guidelines. We also reviewed the clinical trial registry to recognize trends in trial registration in recent years and after a massive failure in a few trials. RESULTS: Phase 1 trials of TGN 1412 and BIA10-2474 would always be remembered as catastrophes for pharmaceutical development plans. Quite often than not, healthy human volunteers are the guinea pigs in this stage of drug development. And, the most important aspect of designing an early phase study is deciding upon the dose to be started with, apart from the selection of cohort and escalation steps. The common principles used for FIH dose calculation include no observed adverse effect level, minimum anticipated biological effect level, pharmacologically active dose, pharmacokinetic/pharmacodynamic approach, and similar drug comparison approach. CONCLUSION: Early phase clinical trials are basically foundation stones on which lies the entire onus of the later stages of development. Deciding FIH dose is a crucial step that necessitates the incorporation of detailed data from the preclinical stages and application of the most conservative approach for the safety/benefit of the volunteers in these studies.

Acute Neurologic Disorder from an Inhibitor of Fatty Acid Amide Hydrolase.

BACKGROUND: A decrease in fatty acid amide hydrolase (FAAH) activity increases the levels of endogenous analogues of cannabinoids, or endocannabinoids. FAAH inhibitors have shown analgesic and antiinflammatory activity in animal models, and some have been tested in phase 1 and 2 studies. In a phase 1 study, BIA 10-2474, an orally administered reversible FAAH inhibitor, was given to healthy volunteers to assess safety. METHODS: Single doses (0.25 to 100 mg) and repeated oral doses (2.5 to 20 mg for 10 days) of BIA 10-2474 had been administered to 84 healthy volunteers in sequential cohorts; no severe adverse events had been reported. Another cohort of participants was then assigned to placebo (2 participants) or 50 mg of BIA 10-2474 per day (6 participants). This report focuses on neurologic adverse events in participants in this final cohort. A total of 4 of the 6 participants who received active treatment consented to have their clinical and radiologic data included in this report. RESULTS: An acute and rapidly progressive neurologic syndrome developed in three of the four participants starting on the fifth day of drug administration. The main clinical features were headache, a cerebellar syndrome, memory impairment, and altered consciousness. Magnetic resonance imaging showed bilateral and symmetric cerebral lesions, including microhemorrhages and hyperintensities on fluid-attenuated inversion recovery and diffusion-weighted imaging sequences predominantly involving the pons and hippocampi. One patient became brain dead; the condition of two patients subsequently improved, but one patient had residual memory impairment, and the other patient had a residual cerebellar syndrome. One patient remained asymptomatic. CONCLUSIONS: An unanticipated severe neurologic disorder occurred after ingestion of BIA 10-2474 at the highest dose level used in a phase 1 trial. The underlying mechanism of this toxic cerebral syndrome remains unknown.

Computational proteome-wide screening predicts neurotoxic drug-protein interactome for the investigational analgesic BIA 10-2474.

The investigational compound BIA 10-2474, designed as a long-acting and reversible inhibitor of fatty acid amide hydrolase for the treatment of neuropathic pain, led to the death of one participant and hospitalization of five others due to intracranial hemorrhage in a Phase I clinical trial. Putative off-target activities of BIA 10-2474 have been suggested to be major contributing factors to the observed neurotoxicity in humans, motivating our study's proteome-wide screening approach to investigate its polypharmacology. Accordingly, we performed an in silico screen against 80,923 protein structures reported in the Protein Data Bank. The resulting list of 284 unique human interactors was further refined using target-disease association analyses to a subset of proteins previously linked to neurological, intracranial, inflammatory, hemorrhagic or clotting processes and/or diseases. Eleven proteins were identified as potential targets of BIA 10-2474, and the two highest-scoring proteins, Factor VII and thrombin, both essential blood-clotting factors, were predicted to be inhibited by BIA 10-2474 and suggest a plausible mechanism of toxicity. Once this small molecule becomes commercially available, future studies will be conducted to evaluate the predicted inhibitory effect of BIA 10-2474 on blood clot formation specifically in the brain.

A call to incorporate systems theory and human factors into the existing investigation of harm in clinical research involving healthcare products.

This is a joint statement from individual pharmacology and pharmaceutical professionals acting in their own capacity, including members of the Alliance for Clinical Research Excellence and Safety (ACRES) and the International Society of Pharmacovigilance (ISoP). By building on the extensive pharmacological and regulatory investigations that already take place, we are calling for a fuller and more robust systems-based approach to the independent investigation of clinical research when serious incidents of harm occur, starting with first-in-human clinical trials. To complement existing activities and regulations, we propose an additional approach blending evidence derived from both pharmacological and organizational science, which addresses human factors and transparency, to enhance organizational learning and continuous improvement. As happens with investigations in other sectors of society, such as the chemical and aviation sector, this systems approach should be seen as an additional way to understand how problems occur and how they might be prevented in the future. We believe that repetition of potentially preventable and adverse outcomes during clinical research, by failing to identify and act upon all systematic vulnerabilities, is a situation that needs urgent change. As we will discuss further on, approaches based on applying systems theory and human factors are much more likely to improve objectivity and transparency, leading to better system design.

Statistical issues in first-in-human studies on BIA 10-2474: Neglected comparison of protocol against practice.

By setting the regulatory-approved protocol for a suite of first-in-human studies on BIA 10-2474 against the subsequent French investigations, we highlight 6 key design and statistical issues, which reinforce recommendations by a Royal Statistical Society Working Party, which were made in the aftermath of cytokine release storm in 6 healthy volunteers in the United Kingdom in 2006. The 6 issues are dose determination, availability of pharmacokinetic results, dosing interval, stopping rules, appraisal by safety committee, and clear algorithm required if combining approvals for single and multiple ascending dose studies.

Implications of the BIA-102474-101 study for review of first-into-human clinical trials.

Over the past 10 years, thousands of first-into-human (FIH) clinical trials have been performed in Europe, with few severe adverse events (SAEs). Each has received detailed prior safety review at both the local clinical research facility and at national drug regulatory authority level. The recent fatal SAE in the BIA-102474-101 clinical trial shows the limitations of this process. Although criticized for not sequentially dosing subjects both within and between cohorts - as recommended by the European Medicines Agency for high-risk compounds after the TeGenero clinical trial disaster in 2006 - BIA-102474-101 was not considered to be high risk. Indeed, compounds with similar mechanisms of action had previously been taken through phase I and II trials without incident, and higher doses had been safely given for longer durations to nonhuman primates. If the available data are comprehensive and accurate, and further investigation does not reveal unreported warning signs, this study has serious implications for ongoing and future review of FIH clinical trials. All preclinical study documents and clinical data collected during the BIA-102474-101 trial should be made available urgently so that lessons can be learnt. In the meantime, reviewers and clinical researchers should always ask for information on drug and target interactions and full reports of preclinical toxicity studies, and plan sequential dosing with longer delays between patients and cohorts, particularly if late SAEs might be anticipated. The use of individual patient pharmacokinetic and dynamic data should guide sequential dosing. A process for systematic risk assessment, like that currently used in the Netherlands, should be applied routinely to all trials with novel compounds.

Clinical pharmacology and tolerability of REC-994, a redox-cycling nitroxide compound, in randomized phase 1 dose-finding studies.

Cerebral cavernous malformation (CCM) has variable clinical symptoms, including potentially fatal hemorrhagic stroke. Treatment options are very limited, presenting a large unmet need. REC-994 (also known as tempol), identified as a potential treatment through an unbiased drug discovery platform, is hypothesized to treat CCMs through a reduction in superoxide, a reactive oxygen species. We investigated the safety, tolerability, and pharmacokinetic profile of REC-994 in healthy volunteers. Single- and multiple-ascending dose (SAD and MAD, respectively) studies were conducted in adult volunteers (ages 18-55). SAD study participants received an oral dose of REC-994 or placebo. MAD study participants were randomized 3:1 to oral doses of REC-994 or matching placebo, once daily for 10 days. Thirty-two healthy volunteers participated in the SAD study and 52 in the MAD study. Systemic exposure increased in proportion to REC-994 dose after single doses of 50-800 mg and after 10 days of dosing over the 16-fold dose range of 50-800 mg. Median Tmax and mean t1/2 were independent of dose in both studies, and the solution formulation was more rapidly absorbed. REC-994 was well tolerated. Treatment-emergent adverse effects across both studies were mild and transient and resolved by the end of the study. REC-994 has a favorable safety profile and was well tolerated in single and multiple doses up to 800 mg with no dose-limiting adverse effects identified. Data support conducting a phase 2 clinical trial in patients with symptomatic CCM.

Mitochondria-targeted antioxidant and glycolysis inhibition: synergistic therapy in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related deaths worldwide. Mito-carboxy proxyl (Mito-CP), a lipophilic cationic nitroxide, accumulates in the mitochondria because of the large negative transmembrane potential. Studies have shown that these agents act by disrupting the energy-producing mechanism, inducing mitochondrial-mediated apoptosis, and also enhancing the action of other chemotherapeutic agents in cancer cells. We hypothesized that the combination of Mito-CP and glycolysis inhibitor, 2-deoxyglucose (2-DG), would synergistically inhibit HCC in vitro. HepG2 cells and primary hepatocytes were treated with various combinations of Mito-CP and 2-DG. Cell cytotoxicity was measured using the methylthiazolyldiphenyl-tetrazolium bromide assay and ATP bioluminescence assay. In addition, caspase 3/7 enzymatic activity was examined after treatment. Mito-CP and 2-DG induced synergistic cytotoxicity in HepG2 cells in a dose-dependent and time-dependent manner, whereas primary cells remained viable and unaffected after treatment. The intracellular ATP levels of HepG2 cells were suppressed within 6 h of combination treatment, whereas primary cells maintained higher levels of ATP. Dose-dependent increases in caspase 3/7 activity occurred in HepG2 cells in a time-dependent manner, showing the initiation of cell death through the apoptotic pathway. These findings indicate that a combination of Mito-CP and 2-DG effectively inhibits HCC growth in vitro. The increase in caspase 3/7 activity supports the occurrence of 2-DG-induced and Mito-CP-induced apoptotic death in HCC. The inability of the compounds to induce cytotoxicity or suppress the production of ATP in primary hepatocytes provides a selective and synergistic approach for the treatment of HCC.

Anticoagulation with otamixaban and ischemic events in non-ST-segment elevation acute coronary syndromes: the TAO randomized clinical trial.

IMPORTANCE: The optimal anticoagulant for patients with non-ST-segment elevation acute coronary syndromes (NSTE-ACS) managed with an invasive strategy remains controversial. OBJECTIVE: To compare the clinical efficacy and safety of otamixaban, a novel intravenous direct factor Xa inhibitor, with that of unfractionated heparin plus downstream eptifibatide in patients with NSTE-ACS undergoing a planned early invasive strategy. DESIGN, SETTING, AND PARTICIPANTS: Randomized, double-blind, active-controlled superiority trial that enrolled 13,229 patients with NSTE-ACS and a planned early invasive strategy, at 568 active sites in 55 countries and conducted between April 2010 and February 2013. A planned interim analysis was conducted for otamixaban dose selection. INTERVENTIONS: Eligible participants were randomized to otamixaban (bolus and infusion, at 1 of 2 doses) or unfractionated heparin plus, at the time of percutaneous coronary intervention, eptifibatide. The otamixaban dose selected at interim analysis was an intravenous bolus of 0.080 mg/kg followed by an infusion of 0.140 mg/kg per hour. MAIN OUTCOMES AND MEASURES: The primary efficacy outcome was the composite of all-cause death or new myocardial infarction through day 7. RESULTS: Rates of the primary efficacy outcome were 5.5% (279 of 5105 patients) randomized to receive otamixaban and 5.7% (310 of 5466 patients) randomized to receive unfractionated heparin plus eptifibatide (adjusted relative risk, 0.99 [95% CI, 0.85-1.16]; P = .93). There were no differences for the secondary end points, including procedural thrombotic complications. The primary safety outcome of Thrombosis in Myocardial Infarction major or minor bleeding through day 7 was increased by otamixaban (3.1% vs 1.5%; relative risk, 2.13 [95% CI, 1.63-2.78]; P < .001). Results were consistent across prespecified subgroups. CONCLUSIONS AND RELEVANCE: Otamixaban did not reduce the rate of ischemic events relative to unfractionated heparin plus eptifibatide but did increase bleeding. These findings do not support the use of otamixaban for patients with NSTE-ACS undergoing planned early percutaneous coronary intervention. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01076764.

Design and rationale of the treatment of acute coronary syndromes with otamixaban trial: a double-blind triple-dummy 2-stage randomized trial comparing otamixaban to unfractionated heparin and eptifibatide in non-ST-segment elevation acute coronary syndromes with a planned early invasive strategy.

BACKGROUND: Otamixaban is a synthetic intravenous direct factor Xa inhibitor, with rapid onset/offset, linear kinetics, and no significant renal elimination. A phase II trial in acute coronary syndromes (ACS) showed a marked reduction in the combined end point of death or myocardial infarction (MI) and similar bleeding rates with otamixaban at midrange doses, compared with unfractionated heparin (UFH) and eptifibatide. DESIGN: The TAO trial is a phase III, randomized, double-blind, triple-dummy controlled trial testing the efficacy of otamixaban over UFH plus eptifibatide in patients with non-ST-segment elevation ACS to be treated with dual oral antiplatelet therapy and an invasive strategy. Approximately 13,220 patients in 55 countries will be randomized (1:1:1 ratio) to receive UFH plus downstream eptifibatide (started pre-percutaneous coronary intervention and continued per label) or otamixaban (0.08 mg/kg intravenous bolus at randomization then 0.100 or 0.140 mg/kg per hour intravenous infusion). An interim analysis was performed after ≥1,969 patients per arm completed 7 days of follow-up and the Data Monitoring Committee selected 1 otamixaban dose (blinded to investigators) to be carried forward using a prespecified algorithm. The primary efficacy outcome is the composite of all-cause mortality or new MI through day 7. The primary safety outcome is thrombolysis in MI major or minor bleeding through day 7. Secondary outcomes include all-cause mortality, recurrent ischemia/infarction resulting in prolonged/recurrent hospitalization, periprocedural angiographic complications, and pharmacokinetic data in 6,000 patients. CONCLUSIONS: The TAO trial will assess the clinical efficacy and safety of otamixaban in non-ST-segment elevation ACS with planned invasive strategy.

Safety, Tolerability, and Pharmacokinetics of FAAH Inhibitor BIA 10-2474: A Double-Blind, Randomized, Placebo-Controlled Study in Healthy Volunteers.

This study evaluated the safety, tolerability, pharmacokinetics, and pharmacodynamics of BIA 10-2474, a fatty acid amide hydrolase (FAAH) inhibitor, after first administration to healthy male and female participants. Participants (n = 116) were recruited into this phase I, double-blind, randomized, placebo-controlled, single ascending dose and multiple ascending dose (10-day) study. The primary outcome was the safety and tolerability of BIA 10-2474. Secondary outcomes were pharmacokinetics of BIA 10-2474 and pharmacodynamics, considering plasma concentrations of anandamide and three other fatty acid amides (FAAs) and leukocyte FAAH activity. Single oral doses of 0.25-100 mg and repeated oral doses of 2.5-50 mg were evaluated. BIA 10-2474 was well tolerated up to 100 mg as a single dose and up to 20 mg once daily for 10 days. In the cohort receiving repeated administrations of 50 mg, there were central nervous system adverse events in five of six participants, one with fatal outcome, which led to early termination of the study. BIA 10-2474 showed a linear relationship between dose and area under plasma concentration-time curve (AUC) across the entire dose range and reached steady state within 5-6 days of administration, with an accumulation ratio, based on AUC0-24h , of <2 on Day 10. BIA 10-2474 was rapidly absorbed with a mean terminal elimination half-life of 8-10 hours (Day 10). BIA 10-2474 caused reversible, dose-related increases in plasma FAAs. In conclusion, we propose that these data, as well as the additional data generated since the clinical trial was stopped, do not provide a complete mechanistic explanation for the tragic fatality.

Nitroxide derivatives for imaging of hypercholesterolemia-induced kidney dysfunction and assessing the effectiveness of antilipidemic drugs.

The present study was designed to clarify the possibility for application of nitroxide derivatives in magnetic resonance imaging (MRI) of hypercholesterolemia-mediated renal dysfunction in mice, as well as to assess the effectiveness of antilipidemic drugs (cholestyramine and ezetimibe). The mice were separated in four groups: (i) on a normal diet (ND) without medication (control); (ii) on a high cholesterol diet (CD) without medication; (iii) CD mice receiving cholestyramine; and (iv) CD mice receiving ezetimibe. In CD mice without medication, a hypercholesterolemia was developed, detected by the increasing of total plasma cholesterol and non-HDL cholesterol, and decreasing of HDL cholesterol. The hypercholesterolemia compromised renal function: blood urea nitrogen, creatine and uric acid increased significantly, accompanied with development of glomerulosclerosis, enhancement of the amount of neutrophils and overexpression of metalloproteinase-9. The mice were subjected to anesthesia and MR imaging was performed on 7 T magnet (T1-weighted incoherent gradient-echo sequence; fast low-angle shot). The region-of-interest was selected within the kidney. The images were obtained before and after injection of contrast probe [carbamoyl-PROXYL (CMP) or Gd-DTPA]. In the kidney of ND mice, the MRI signal intensity increased after injection of CMP, reached a maximum (very well-defined renal filtration peak) and decreased to the baseline level within 14 min. In kidney of CD mice, the CMP-mediated enhancement of MRI signal was not detected. Antilipidemic drugs patially abolished the effect of hypercholesterolemia on CMP-enhanced MRI in the kidney. The kinetic curves of Gd-enhanced MRI signal had also different profiles in the kidney of ND and CD mice. They were similar to the profiles of the kinetic curves, obtained from MR urography of healthy human and human with renal pathology, respectively. The present study suggests that CMP is a suitable MRI contrast probe for visualization of hypercholesterolemia-induced renal dysfunction in intact animals and the assessment of the efficacy of antilipidemic drugs. The probe was applied at a concentration that was 3 times lower than the LD50 for intravenous administration in mice. Since the probe is excreted by the kidney, it could be considered harmless for mammalians in the selected dose and appropriate candidate for translational research.

The influence of propiverine hydrochloride on cardiac repolarization in healthy women and cardiac male patients.

OBJECTIVE: Two comprehensively designed mono-centric ECG studies were performed to investigate the influence of propiverine hydrochloride and its main metabolite propiverine-N-oxide on cardiac function with regard to QTc prolongation, QTc dispersion and T-wave shape. METHODS: The first study was conducted on 24 healthy females, followed by a second study on 24 male patients with coronary heart disease (CHD) and a pathological Pardee-Q-wave in the ECG. Both studies were placebo-controlled and compared the effects of single (30 mg s.i.d.) and multiple dosing (15 mg t.i.d.) of propiverine hydrochloride in a crossover design over 6 and 13 days, respectively. In CHD patients, the ECG was recorded under standardized exercise stress conditions. RESULTS: An effect of propiverine on cardiac safety in healthy women and male patients with CHD could not be determined by the evaluation of QTc intervals derived from ECG under the following conditions: (1) single dosage; (2) steady-state and elevated dosage; (3) healthy female volunteers and male CHD patients; (4) resting and stress conditions in CHD patients. Moreover, other ECG parameters like QT dispersion, T-wave shape, and U-wave occurrence were not affected by propiverine compared to placebo after single or repeated dosing to reach steady-state conditions. CONCLUSION: These results reflect and confirm preclinical data as well as clinical observations on hundreds of volunteers and numberless patients suffering from overactive bladder syndrome and neurogenic detrusor overactivity who were treated with propiverine hydrochloride over nearly three decades in Europe and Japan.

Trapping of DNA radicals with the nitrone spin trap 5,5-dimethyl-1-pyrroline N-oxide and genotoxic damage: Recent advances using the immuno-spin trapping technology.

Immuno-spin trapping detection of DNA radicals with the nitrone spin trap 5,5-dimethyl-1-pyrrloine N-oxide (DMPO) has made important contributions towards the understanding of DNA radicalization and genotoxicity at sites of inflammation. At sites of inflammation, one-electron oxidants and chloramines decay induce oxidation of genomic DNA, genotoxicity and cell transformation. Radicalization of DNA can result in either single- or double-strand breaks, or end-oxidation products at the sugar or bases. If not repaired, these modifications can lead to mutations and cell transformation. If trapped with DMPO, DNA-centered radical decay and subsequent formation of end-oxidation products are blocked. Herein we discuss recent literature regarding the use of immuno-spin trapping with DMPO to study DNA-centered radicals and their involvement in genotoxicity. This technique has shown the critical role of DNA radicalization in 8-oxo-dG formation and DNA strand breaks in isolated DNA, cells and in whole animals. Combination of technologies, including immuno-spin trapping and powerful chromatographic and sequencing techniques are needed to move forward the field towards the detection of specific genes that are susceptible to oxidative damage in cells located at sites of inflammation. This is important in order to provide novel information about genotoxicity mechanisms, as well as therapeutic possibilities of DMPO or its derivatives for preventing DNA-centered radical-mediated carcinogenesis.

2-Hydroxypyridine N-Oxide is not genotoxic in vivo.

2-Hydroxypyridine N-oxide (HOPO) is an important coupling reagent used in pharmaceutical synthesis. Our laboratory previously reported HOPO as equivocal in the Ames assay following extensive testing of multiple lots of material. Given the lack of reproducibility between lots of material and the weak increase in revertants observed, it was concluded that it would be highly unlikely that HOPO would pose a mutagenic risk in vivo. The purpose of the current investigation was to assess experimentally in rats the mutagenic (Pig-a mutation induction) and more broadly genotoxic (micronucleus and comet induction) potential of HOPO. Rats were administered HOPO (0, 50, 150, 300, and 500 mg/kg/day) by oral gavage for 28 days. At the end of study, the following parameters were assessed: frequency of Pig-a mutant red blood cells and reticulocytes, frequency of peripheral blood micronuclei, and the incidence of comet formation in liver. Toxicokinetic data collected on study Days 1 and 28 demonstrated systemic exposure to HOPO. Although there were no overt clinical signs, animals treated with HOPO showed a dose-related decrease in body weight gain. There were no increases observed in any of the genotoxicity endpoints assessed. The results from this study further support the conclusion that in the context of pharmaceutical synthesis, HOPO should not be considered a mutagenic impurity but rather controlled as a normal process-related impurity. Environ. Mol. Mutagen. 2019. © 2019 Wiley Periodicals, Inc.

Randomized, double-blind, dose-ranging study of otamixaban, a novel, parenteral, short-acting direct factor Xa inhibitor, in percutaneous coronary intervention: the SEPIA-PCI trial.

BACKGROUND: The optimal anticoagulant regimen for percutaneous coronary intervention (PCI) remains to be determined. Otamixaban, a selective and direct inhibitor of factor Xa, was investigated in patients undergoing nonurgent percutaneous coronary intervention. METHODS AND RESULTS: In this double-blind, double-dummy, parallel-group, dose-ranging trial, 947 patients were randomly assigned to either 1 of 5 weight-adjusted otamixaban regimens or weight-adjusted unfractionated heparin (UFH) before percutaneous coronary intervention. The primary end points were change in prothrombin fragments 1+2 (F1+2), and anti-factor Xa activity. The main secondary end points were Thrombolysis In Myocardial Infarction (TIMI) bleeding at day 3 or hospital discharge (whichever came first) and 30-day ischemic events. The median change in F1+2 from baseline to the end of infusion was greater with the highest otamixaban dose compared with UFH (-0.3 versus -0.2 ng/mL, P=0.008). Anti-factor Xa levels were 65, 155, 393, 571, and 691 ng/mL with otamixaban doses 1 to 5, respectively. Significant TIMI bleeding (major or minor) occurred in 2.0%, 1.9%, 3.8%, 3.9%, and 2.6% of patients receiving otamixaban doses 1 to 5, respectively, and in 3.8% of patients receiving UFH. Four TIMI major bleeds were observed. Ischemic events occurred in 5.8%, 7.1%, 3.8%, 2.5%, and 5.1% of patients receiving otamixaban doses 1 to 5, respectively, and in 5.6% of patients receiving UFH. CONCLUSIONS: Otamixaban reduced F1+2 significantly more than UFH at the highest dose regimen, whereas no significant difference in the incidence of TIMI bleeding was observed between the otamixaban and UFH groups. These results set the stage for adequately powered clinical outcome trials of selective direct factor Xa inhibition in patients with acute coronary syndromes.

Acute but not chronic tempol treatment increases ischemic and reperfusion ventricular arrhythmias in open-chest rats.

The effect of the chronic and acute antioxidant tempol (superoxide dismutase mimetic) treatment on cardiac ischemic tolerance was investigated in adult male Wistar rats. The first experimental group was given tempol (1 mM) in drinking water for three weeks, the second group received tempol (100 mg/kg, i.v.) 10 min before test ischemia, and control rats received the same volume of solvent. Anesthetized open-chest animals (pentobarbitone 60 mg/kg, i.p.) were subjected to 20-min coronary artery occlusion and 3-h reperfusion for infarct size determination. Ventricular arrhythmias were monitored during ischemia and at the beginning (5 min) of reperfusion. Acute tempol administration shifted the time profile of ischemic arrhythmias to the later phase and significantly increased the number of ischemic and reperfusion premature ventricular complexes, respectively (504 +/- 127 and 84 +/- 21) as compared with the chronically treated group (218 +/- 36 and 47 +/- 7) or controls (197 +/- 26 and 31 +/- 7). Acute tempol-treated rats exhibited a tendency to decrease infarct size (P = 0.087). The mechanism of proarrhythmic tempol action during ischemia and reperfusion remains to be elucidated.

TGN-1412 and BIA-2474 Trials with Tragic End: Lessons Learnt To Make Clinical Trials Safer.

BACKGROUND: Globally, there have been tremendous efforts by regulatory authorities to make clinical trials safer by making stringent clinical trial regulations. Despite this, we witnessed several tragic events. TGN1412 and BIA 10-2474 phase I trials are infamous trails in which healthy volunteers either succumbed to severe adverse effects or faced irreversible impairments of the test drug. Such afflictions in clinical trials are not only turbulent to the image of pharmaceutical industry but it also conveys dispiriting message for clinical trial participants. OBJECTIVE: To make clinical trials safer for participants, some regulatory changes are warranted. METHODS: Some stipulated measures to improve safety of clinical trial participants include inclusion of patients instead of healthy volunteers in phase I clinical trials, all compounds which are used for first time in humans should be considered as high risk compounds, amendments in first in human clinical trial design to N of 1 randomized control trial in place of 6+2 design with the sequential dosing of subjects both within and between cohorts and the individual patient pharmacokinetic and pharmacodynamic data should be used to calculate sequential dosing. Besides these, there should be appropriate process for systematic risk assessment involving the use of statistical techniques to select pertinent risk factors with high predictive values of studies or sites that may be procumbent to non-compliance. CONCLUSION: Inclusion of above mentioned measures in clinical trials are bound to make them safer and may help in pacifying the insecurity that has emerged among humans to participate in clinical trials.

Discovery of a Potent, Long-Acting, and CNS-Active Inhibitor (BIA 10-2474) of Fatty Acid Amide Hydrolase.

Fatty acid amide hydrolase (FAAH) can be targeted for the treatment of pain associated with various medical conditions. Herein we report the design and synthesis of a novel series of heterocyclic-N-carboxamide FAAH inhibitors that have a good alignment of potency, metabolic stability and selectivity for FAAH over monoacylglycerol lipase (MAGL) and carboxylesterases (CEs). Lead optimization efforts carried out with benzotriazolyl- and imidazolyl-N-carboxamide series led to the discovery of clinical candidate 8 l (3-(1-(cyclohexyl(methyl)carbamoyl)-1H-imidazol-4-yl)pyridine 1-oxide; BIA 10-2474) as a potent and long-acting inhibitor of FAAH. However, during a Phase I clinical trial with compound 8 l, unexpected and unpredictable serious neurological adverse events occurred, affecting five healthy volunteers, including the death of one subject.