Pharmacokinetic/pharmacodynamic model of a methionine starvation based anti-cancer drug.

A new therapeutic approach against cancer is developed by the firm Erytech. This approach is based on starved cancer cells of an amino acid essential to their growth (the L-methionine). The depletion of plasma methionine level can be induced by an enzyme, the methionine-γ-lyase. The new therapeutic formulation is a suspension of erythrocytes encapsulating the activated enzyme. Our work reproduces a preclinical trial of a new anti-cancer drug with a mathematical model and numerical simulations in order to replace animal experiments and to have a deeper insight on the underlying processes. With a combination of a pharmacokinetic/pharmacodynamic model for the enzyme, substrate, and co-factor with a hybrid model for tumor, we develop a "global model" that can be calibrated to simulate different human cancer cell lines. The hybrid model includes a system of ordinary differential equations for the intracellular concentrations, partial differential equations for the concentrations of nutrients and drugs in the extracellular matrix, and individual based model for cancer cells. This model describes cell motion, division, differentiation, and death determined by the intracellular concentrations. The models are developed on the basis of experiments in mice carried out by Erytech. Parameters of the pharmacokinetics model were determined by fitting a part of experimental data on the concentration of methionine in blood. Remaining experimental protocols effectuated by Erytech were used to validate the model. The validated PK model allowed the investigation of pharmacodynamics of cell populations. Numerical simulations with the global model show cell synchronization and proliferation arrest due to treatment similar to the available experiments. Thus, computer modeling confirms a possible effect of treatment based on the decrease of methionine concentration. The main goal of the study is the development of an integrated pharmacokinetic/pharmacodynamic model for encapsulated methioninase and of a mathematical model of tumor growth/regression in order to determine the kinetics of L-methionine depletion after co-administration of Erymet product and Pyridoxine.

Twice- or Once-Daily Dosing of Direct Oral Anticoagulants, a systematic review and meta-analysis.

AIM: The direct oral anticoagulants (DOAC) have similar half-lives, but the dosing regimen varies between once daily (QD) or twice daily (BID). For some prescribers, the QD regimen improves compliance. Others prefer BID regimens to promote better stability of plasma concentrations, particularly in the event of missed doses. Limited level of evidence provides guidance about the best treatment strategy. The purpose of this study was to compare the treatment effect of QD vs. BID administration of DOACs in major orthopedic surgery (MOS), non-valvular atrial fibrillation (NVAF), venous thromboembolism (VTE), and acute coronary syndrome (ACS). METHODS: We conducted a systematic review up to April 2020. We included phase II clinical trials comparing DOAC QD vs BID with same daily dose. We extracted data for the occurrence of major thrombosis (proximal deep vein thrombosis, pulmonary embolism, myocardial infarction, ischemic stroke) and major hemorrhage (ISTH criteria and recommendations of the European Medicines Agency for surgical patients). Relative risks (RR) were combined using a fixed and random effects weighted meta-analysis. RESULTS: Twelve randomized, controlled, phase II trials were included (10,716 patients), representing 24 dosing regimen comparisons of apixaban, darexaban, edoxaban, rivaroxaban, letaxaban, and dabigatran. There was no difference for major thrombotic event (RRBID/QD = 1.06, 95%IC 0.86-1.30) nor for major bleeding (RRBID/QD = 1.02, 95%IC 0.84-1.23) between the BID vs QD regimens, without heterogeneity (I2 = 0%). CONCLUSION: Our study does not support a global difference in term of efficacy and safety of the BID and QD regimens of DOAC in MOS, NVAF, VTE and ACS.

Impact of terminating reimbursement of symptomatic slow-acting drugs in osteoarthritis in France on volume and cost of drug deliveries, assessed with administrative databases.

WITH OSTEOARTHRITIS (OA): As one of the leading causes of disability in adults worldwide, its toll on patients and its economic burden for payers are substantial. The issue of change in OA management with the evolution of reimbursement schemes needs to be addressed. OBJECTIVE: To assess the impact of terminating the reimbursement of symptomatic slow-acting drugs in OA (SYSADOAs) in France in terms of volume and cost, from a healthcare payer perspective. PRINCIPAL RESULTS: We obtained costs and volumes from French public national databases. We considered three exposure periods around cutoff dates according to decisions of decreased then terminated SYSADOA reimbursement. The periods included 19 345 (control), 20 066 (secondary), and 16 200 (primary) patients, respectively. Mean ages were 66.2 (±11.8), 65.3 (±11.6) and 64.6 (±11.5) years and about 70% were women. The volume of nonsteroidal anti-inflammatory drug (NSAID) deliveries estimated by defined daily doses (DDDs) decreased during the periods from 40.5 (±76.3) DDDs per patient in 2008 to 29.6 (±66.4) in 2015. The volume of analgesic deliveries increased slowly over the three periods, from 70.2 (±108.9) DDDs in 2008 to 76.9 (±123.1) in 2015 for all patients. MAJOR CONCLUSIONS: Our results did not show a measurable impact of terminating SYSADOA reimbursement on the delivery of NSAIDs and analgesics or on hospitalizations. However, neither do they allow for concluding that terminating SYSADOA reimbursement did not generate an increase in deliveries of non-reimbursed drugs, with their associated potential risks for public health.

Dynamical modeling of pro- and anti-inflammatory cytokines in the early stage of septic shock.

A dynamical model of the pathophysiological behaviors of IL18 and IL10 cytokines with their receptors is tested against data for the case of early sepsis. The proposed approach considers the surroundings (organs and bone marrow) and the different subsystems (cells and cyctokines). The interactions between blood cells, cytokines and the surroundings are described via mass balances. Cytokines are adsorbed onto associated receptors at the cell surface. The adsorption is described by the Langmuir model and gives rise to the production of more cytokines and associated receptors inside the cell. The quantities of pro and anti-inflammatory cytokines present in the body are combined to give global information via an inflammation level function which describes the patient's state. Data for parameter estimation comes from the Sepsis 48 H database. Comparisons between patient data and simulations are presented and are in good agreement. For the IL18/IL10 cytokine pair, 5 key parameters have been found. They are linked to pro-inflammatory IL18 cytokine and show that the early sepsis is driven by components of inflammatory character.

Association between difference in blood pressure reduction and risk of cardiovascular events in a type 2 diabetes population: A meta-regression analysis.

AIM: Recent US recommendations indicate a target blood pressure (BP) of 130/80mmHg for patients with type 2 diabetes (T2D). Our aim was to characterize the association between risk of cardiovascular events and differences in BP decreases in randomized trials of a T2D population. METHODS: A systematic search was made for randomized clinical trials assessing the effects of antihypertensive treatments in T2D patients on mortality, and fatal and non-fatal cardiovascular events, using a meta-regression technique to explore the influence of BP decreases on treatment effects. RESULTS: A total of 88,503 patients from 44 randomized trials were included. There was no significant association between BP decreases and risk of all-cause or cardiovascular mortality, cardiovascular events or myocardial infarction. However, stroke risk was influenced by BP decreases: compared with no reduction, a 10-mmHg reduction in systolic BP was associated with a relative odds ratio (OR) decrease of 33% (OR: 0.67, 95% CI: 0.54-0.82), and a 5-mmHg diastolic BP reduction was associated with a relative OR decrease of 38% (OR: 0.62, 95% CI: 0.50-0.76). Restricting the analysis to double-blind studies did not change the results for diastolic BP. CONCLUSION: A reduction in BP lowers the risk of stroke, but does not appear to affect the risk of other cardiovascular events in a T2D population.

Efficiency of physical therapy on postural imbalance after stroke: study protocol for a systematic review and meta-analysis.

INTRODUCTION: Stroke frequently results in balance disorders, leading to lower levels of activity and a diminution in autonomy. Current physical therapies (PT) aiming to reduce postural imbalance have shown a large variety of effects with low levels of evidence. The objectives are to determine the efficiency of PT in recovering from postural imbalance in patients after a stroke and to assess which PT is more effective. METHODS AND ANALYSIS: We will search several databases from inception to October 2015. Only randomised controlled trials assessing PT to recover from poststroke postural imbalance in adults will be considered.Outcome measures will be the Berg Balance Scale (BBS), the Postural Assessment Scale for Stroke (PASS), the 'weight-bearing asymmetry' (WBA), the 'centre of pressure' (COP) and the 'limit of stability' (LOS). WBA, COP and LOS are measured by a (sitting or standing) static evaluation on force plate or another device.Two independent reviewers will screen titles, abstracts and full-text articles, evaluate the risk of bias and will perform data extraction. In addition to the outcomes, measures of independence will be analysed. This study will aim at determining the effects of PT on the function (WBA, COP, LOS), the activity (BBS, PASS) and the independence of patients. Subgroup analyses will be planned according to the location of brain lesion (hemispheric, brainstem or cerebellum), the time since stroke (early, late, chronic), the PT (type, main aim (direct effect or generalisation), overall duration), the type of approaches (top-down or bottom-up) and the methodological quality of studies. ETHICS AND DISSEMINATION: No ethical statement will be required. The results will be published in a peer-reviewed journal. This meta-analysis aims at managing the rehabilitation after postural imbalance by PT after a stroke. TRIAL REGISTRATION NUMBER: Prospero CRD42016037966;Pre-results.

Efficacy and safety of DPP-4 inhibitors in patients with type 2 diabetes: Meta-analysis of placebo-controlled randomized clinical trials.

BACKGROUND: Guidelines for type 2 diabetes (T2D) recommend reducing HbA1c through lifestyle interventions and glucose-lowering drugs (metformin, then combination with dipeptidyl peptidase-4 inhibitors [DPP-4Is] among other glucose-lowering drugs). However, no double-blind randomized clinical trial (RCT) compared with placebo has so far demonstrated that DDP-4Is reduce micro- and macrovascular complications in T2D. Moreover, the safety of DPP-4Is (with increased heart failure and acute pancreatitis) remains controversial. METHODS: A systematic review of the literature (PubMed, Cochrane Library Central Register of Controlled Trials [CENTRAL] and https://clinicaltrials.gov), including all RCTs vs placebo published up to May 2015 and the Trial Evaluating Cardiovascular Outcomes with Sitagliptin (TECOS), published June 2015, was performed. Primary endpoints were all-cause mortality and death from cardiovascular causes; secondary endpoints were macrovascular and microvascular events. Safety endpoints were acute pancreatitis, pancreatic cancer, serious adverse events and severe hypoglycaemia. RESULTS: A total of 36 double-blind RCTs were included, allowing analyses of 54,664 patients. There were no significant differences in all-cause mortality (RR=1.03, 95% confidence interval [CI]=0.95-1.12), cardiovascular mortality (RR=1.02, 95% CI=0.92-1.12), myocardial infarction (RR=0.98, 95% CI=0.89-1.08), strokes (RR=1.02, 95% CI=0.88-1.17), renal failure (RR=1.06, 95% CI=0.88-1.27), severe hypoglycaemia (RR=1.14, 95% CI=0.95-1.36) and pancreatic cancer (RR=0.54, 95% CI=0.28-1.04) with the use of DPP-4Is. However, DDP-4Is were associated with an increased risk of heart failure (RR=1.13, 95% CI=1.01-1.26) and of acute pancreatitis (RR=1.57, 95% CI=1.03-2.39). CONCLUSION: There is no significant evidence of short-term efficacy of DPP-4Is on either morbidity/mortality or macro-/microvascular complications in T2D. However, there are warning signs concerning heart failure and acute pancreatitis. This suggests a great need for additional relevant studies in future.

Multivariate meta-analysis using individual participant data.

When combining results across related studies, a multivariate meta-analysis allows the joint synthesis of correlated effect estimates from multiple outcomes. Joint synthesis can improve efficiency over separate univariate syntheses, may reduce selective outcome reporting biases, and enables joint inferences across the outcomes. A common issue is that within-study correlations needed to fit the multivariate model are unknown from published reports. However, provision of individual participant data (IPD) allows them to be calculated directly. Here, we illustrate how to use IPD to estimate within-study correlations, using a joint linear regression for multiple continuous outcomes and bootstrapping methods for binary, survival and mixed outcomes. In a meta-analysis of 10 hypertension trials, we then show how these methods enable multivariate meta-analysis to address novel clinical questions about continuous, survival and binary outcomes; treatment-covariate interactions; adjusted risk/prognostic factor effects; longitudinal data; prognostic and multiparameter models; and multiple treatment comparisons. Both frequentist and Bayesian approaches are applied, with example software code provided to derive within-study correlations and to fit the models.

Is HbA1c a valid surrogate for macrovascular and microvascular complications in type 2 diabetes?

Recent recommendations regarding type 2 diabetes (T2D) patients' treatments have focused on personalizing glycosylated haemoglobin (HbA1c) targets. Because the relationship between HbA1c and diabetes prognosis has been established from large prospective cohorts, it is valid to question the extrapolation from population-based risk reduction estimations to individual predictions. Our study aimed to investigate the relationship between HbA1c reductions and clinical outcomes in randomized controlled trials (RCTs), using a meta-regression approach. Included were RCTs comparing intensive vs. standard glucose-lowering regimens for cardiovascular events and microvascular complications in T2D patients. Eight studies (33,396 patients) providing data for HbA1c reductions were found. In our meta-regression, HbA1c decreases were not significantly associated with reductions in our main study outcomes: total and cardiovascular mortality. They were also not associated with any of the secondary endpoints, including myocardial infarction, stroke and severe hypoglycaemia. Sensitivity analysis showed a significant correlation only between HbA1c-lowering and severe hypoglycaemia (P = 0.014). Meta-regression analysis could find no significant association between HbA1c-lowering and a decrease in clinical outcomes, thereby questioning the use of HbA1c as a surrogate outcome for T2D-related complications. Thus, RCTs vs. placebo are urgently required to evaluate the risk-benefit ratios of therapeutic strategies beyond HbA1c control in T2D patients.

Can we identify response markers to antihypertensive drugs? First results from the IDEAL Trial.

Current antihypertensive strategies do not take into account that individual characteristics may influence the magnitude of blood pressure (BP) reduction. Guidelines promote trial-and-error approaches with many different drugs. We conducted the Identification of the Determinants of the Efficacy of Arterial blood pressure Lowering drugs (IDEAL) Trial to identify factors associated with BP responses to perindopril and indapamide. IDEAL was a cross-over, double-blind, placebo-controlled trial, involving four 4-week periods: indapamide, perindopril and two placebo. Eligible patients were untreated, hypertensive and aged 25-70 years. The main outcome was systolic BP (SBP) response to drugs. The 112 participants with good compliance had a mean age of 52. One in every three participants was a woman. In middle-aged women, the SBP reduction from drugs was -11.5 mm Hg (indapamide) and -8.3 mm Hg (perindopril). In men, the response was significantly smaller: -4.8 mm Hg (indapamide) and -4.3 (perindopril) (P for sex differences 0.001 and 0.015, respectively). SBP response to perindopril decreased by 2 mm Hg every 10 years of age in both sexes (P=0.01). The response to indapamide increased by 3 mm Hg every 10 years of age gradient in women (P=0.02). Age and sex were important determinants of BP response for antihypertensive drugs in the IDEAL population. This should be taken into account when choosing drugs a priori.

Tranexamic acid for epistaxis in hereditary hemorrhagic telangiectasia patients: a European cross-over controlled trial in a rare disease.

BACKGROUND: Hereditary hemorrhagic telangiectasia (HHT) is a genetic disorder associated with abnormal angiogenesis and disabling epistaxis. Tranexamic acid (TA) has been widely used in the treatment of these severe bleeds but with no properly designed trial. OBJECTIVES: To demonstrate the efficacy of TA in epistaxis in HHT patients and to explore its safety of use. PATIENTS/METHODS: A randomized, placebo-controlled, double-blind, cross-over trial was conducted. Participants were randomized to receive TA (3 g a day) then placebo or the opposite sequence. The main analysis compared intra-individual mean duration of epistaxis under TA vs. placebo on a log scale. The primary outcome was the mean duration of epistaxis per month, assessed with specific grids to be completed by participants. The number of epistaxis episodes was recorded as a secondary outcome. RESULTS: A total of 118 randomized patients contributed to the statistical analysis. The mean duration of epistaxis per month was significantly shorter with TA than placebo (0.19 on the log scale; SD = 0.07; P = 0.005), corresponding to a decrease of 17.3% (15.7 min) in the duration of epistaxis per month (CI 95%, 5.5-27.6). The median number of epistaxis episodes per month was 22.1 episodes in the placebo arm vs. 23.3 episodes in the TA arm. No thrombophlebitis was observed. CONCLUSIONS: In the ATERO study, we demonstrated a significant decrease in the duration of epistaxis in HHT patients taking TA. No safety issues were recorded in our cohort of patients.

Effects of pharmacological treatments on micro- and macrovascular complications of type 2 diabetes: what is the level of evidence?

Antidiabetic drugs for type 2 diabetes receive marketing authorization if they show efficacy in reducing levels of HbA(1c). However, efficacy on this biological criterion does not necessarily reflect clinical benefit to patients. Several randomized clinical trials have shown that antidiabetic drugs reduce HbA(1c) without a corresponding reduction in clinical events. This suggests a need to focus on the clinical effectiveness (morbimortality criteria) of our available antidiabetic drugs. In this non-extensive review of the literature, it was found that none of the current antidiabetic drugs have clearly proven their superiority over placebo in the gold standard double-blind randomized clinical trials. Thus, in 2013, the level of evidence for the clinical efficacy of antidiabetic drugs is disappointing and does not support the millions of prescriptions being written for them.

Are we using blood pressure-lowering drugs appropriately? Perhaps now is the time for a change.

This topic seems particularly appropriate since this year is the 20th Anniversary of the Cochrane Collaboration. The Cochrane Collaboration and the Hypertension Review Group have played a leading role in advancing the evidence-based agenda that has challenged many of our ways of thinking and approaches to treating patients.

Efficacy of a home-based intervention programme on the physical activity level and functional ability of older people using domestic services: a randomised study.

OBJECTIVE: Our main objective was to assess whether a home-based program supervised by home helpers (HH) during their normal working hours can prevent excessive sedentariness (mainly maximum walking time and distance) and preserve functional status in elderly people at risk for frailty or disability and using domestic services. DESIGN: A four-month, open label, randomised trial with two groups called "prevention" and "control". SETTING: In the homes of study participants. PARTICIPANTS: The participants were all over 78 years old, lived independently at home, and received the visits of HHs at least once a week. INTERVENTION: The intervention combined a self-administered exercise program, with 10 g amino-acid supplementation under the supervision of HHs. MEASUREMENTS: Main outcome measures included physical activity (the PASE questionnaire), functional tests, nutritional and autonomy scores, and compliance (50% or more was considered satisfactory). Non-parametric methods were used for comparisons between the two groups. A linear regression model was fitted to assess the effect of the intervention on the relative variation of outcomes, adjusted for unbalanced baseline co-variables. RESULTS: One hundred and two persons (prevention n=53, control n=49) with a median age of 85 years were included. Their median Activities of Daily Living and Instrumental Activities of Daily Living (IADL) scores were 6 and 7 respectively. Twenty-three (44%) were good compliers for both interventions. The maximum walking time remained stable while decreasing by 25% in the control group (p=0.0015); and fewer participants had a worsened IADL score in the prevention group (p=0.05). The baseline IADL Score was significantly associated with good compliance to the prevention program (p=0.0011). In good compliers, maximum walking distance and maximum walking time increased by 29.15% (0.0 to 66.7) and 33.3% (-20.0 to 50.0) respectively. CONCLUSION: This study confirms the feasibility of a prevention program supervised by HHs, and some benefit from the intervention and identifies predictors for better compliance. It will help in the design of prevention trials for elderly people at risk for frailty.

[Active drug monitoring of adverse drug reactions in pediatric emergency department]. / Recueil systématique et actif des évènements indésirables médicamenteux chez les enfants admis aux urgences pédiatriques.

OBJECTIVES: The aim of this study was to systematically evaluate adverse drug reactions (ADRs) in children consulting at the pediatric emergency unit during a 6-month period. METHOD: The regional pharmacovigilance center (CRPV) and the department of clinical pharmacology prospectively and systematically recorded all potential ADRs among patients younger than 18 years of age in the pediatric emergency unit reported at the daily staff meetings. All cases were then screened and validated by the CRPV. For validated cases, preventability, seriousness, and off-label use were evaluated. RESULTS: During the study period, from 1 March to 1 September 2005, 90 children presented potential adverse drug events. ADRs were confirmed in 43 patients, 19 females and 24 males. Thirty-four patients (79%) were under the age of 5. According to the European definition, 14 patients (33%) had serious ADRs. One anaphylactic shock after amoxicillin injection; antimalarial prophylaxis misuse leading to convulsive status epilepticus, convulsion, and coma after hepatitis B and MMR vaccines were deemed life-threatening. Three ADRs were considered avoidable. Antibiotics and vaccines were the most common possible cause of ADRs (76%). Skin reactions (n=27), fever (n=8), and gastric disorders (n=5) were the most common clinical manifestations. CONCLUSIONS: Because ADRs were reported by clinicians on a voluntary basis, serious ADRs were probably reported more systematically. Compared to a similar period without active monitoring, active drug monitoring of ADRs doubled the number of confirmed cases 43 vs 17, p<0.001. Close collaboration between the pharmacovigilance center, pharmacologists, and clinicians is necessary and seems feasible for improving the monitoring of ADRs in children.

[Some reflexions about double blind]. / Quelques réflexions sur le double insu.

LITERATURE FINDINGS: Randomized, double blind, placebo-controlled clinical trials are currently the best means of demonstrating the clinical effectiveness of drugs. The double blind procedure, when ethically and technically feasible, is a necessary condition for validating results and for causal attribution of the observed difference between the two groups to the tested drug's pharmacological effect. COMMENTS: In practice, however, it appears that patients and independent investigators can guess who receives the drug and who receives a placebo through side effects, which are usually more frequent in patients receiving the drug. This phenomenon effectively "breaks the blind" and represents as such a major methodological bias, which cannot be avoided as it is inseparable of the drug's effect. CONCLUSION: The impact of this "unavoidable" double blind breach nevertheless remains unclear. While it can reasonably be assumed that it may modify subjective symptoms such as anxiety or pain through suggestion, its influence on objective criteria remains to be demonstrated.

[Readability of informed consent forms for subjects participating in biomedical research: updating is required]. / Lisibilité de l'information écrite destinée aux sujets se prêtant à une recherche biomédicale: une nécessaire remise en question.

OBJECTIVE: We compared informed consent forms of subjects participating in biomedical research with those of references texts in order to determine the factors that influence readability. METHODS: We assessed the readability of 73 informed consent forms of research protocols conducted in the clinical investigation centres in the Rhone-Alpes area, and then compared them with 33 reference texts corresponding to 5 French school grades (first year infant, primary school, GCS level, high school, and classics aggregation), using the Flesch test and Cordial" analyser. RESULTS: Median Flesch scores were 66 for the first year infant level, 62 for the primary school level, 58 for the GCS level, 42 for the high school level, and 43 for the aggregation level. It was 22 for the informed consent forms. Median Cordial scores were 86 for the first year infant level, 77 for the second, 74 for the third, 49 for the fourth, 43 for the fifth. It was 1 for the informed consent forms. No methodological factor correlated with Flesch and Cordial" results. CONCLUSION: The quantitative readability scores for informed consent forms for subjects participating in biomedical research are low, lower than those proposed to aggregation candidates, whatever the type of protocol. Some thought must be given to the impact of the reduced readability on patients' understanding, and steps should be taken to improve the readability of the forms.