Towards a better use of scientific advice for developers of advanced therapies.

Scientific advice (SA) is an important tool offered by regulators to help developers generate robust evidence on a medicine's benefits and risks. Drawing on accumulated experience and looking at the SA provided by the European Medicines Agency in 2018 to advanced therapy medicinal products originally developed by public bodies, we discuss most commonly raised issues and the complexity and timings of the questions posed. Earlier and more frequent SA could help advanced therapy medicinal product developers to pre-empt delays at the marketing authorisation stage. Carefully addressing quality and nonclinical issues before entering the pivotal phase of development will clear the path for a smooth clinical development and successful marketing authorisation.

Association study of the CTH 1364 G>T polymorphism with coronary artery disease in the Greek population.

Background Cystathionine γ-lyase enzyme, which is encoded by the CTH gene, is responsible for hydrogen sulfide (H2S) production in the endothelium. The CTH 1364 G>T polymorphism may alter the CTH expression and H2S bioavailability, thus leading to atherosclerosis and coronary artery disease (CAD). We examined the potential association of the CTH 1364 G>T polymorphism with CAD. Methods The CTH 1364 G>T polymorphism was determined in 178 coronary artery bypass grafting (CABG) patients and 156 non-atherosclerotic controls of Greek Caucasian origin using the PCR-RFLP method. Results No significant difference in the frequency of the CTH 1364 G>T genotypes (p = 0.281) and alleles (p = 0.265) was found between the CABG patients and controls. After conducting stratification according to sex, analysis showed a numerical difference in the CTH 1364 TT genotype frequency in female participants that did not reach statistical significance (16.3% and 8.5% in the CABG and controls, respectively, p = 0.26). The frequency of the CTH 1364 TT genotype between the male CABG patients and controls did not differ (p = 0.507). Conclusions The CTH 1364 G>T polymorphism was not associated with CAD in the studied population. However, interestingly, a higher - if not significantly so - CTH 1364 TT genotype frequency was present in female CABG patients compared with female controls. Larger studies are necessary to conclude on the potential overall or gender-driven association between CTH 1364 G>T gene polymorphism and CAD.

Carotid intima-media thickness is an independent predictor of all-cause mortality and cardiovascular morbidity in patients with diabetes mellitus type 2 and chronic kidney disease.

BACKGROUND: Intima-Media-Thickness of the carotid artery wall (cIMT) is a strong predictor of cardiovascular (CV) disease. The aim of this study was to investigate the significance of cIMT as an independent prognostic factor for CV morbidity and mortality in patients with chronic kidney disease (CKD) and diabetes mellitus type 2 (DM2). METHODS: The study included 142 diabetic patients in different stages of CKD. Patients were categorized into two groups according to low (≤0.86 mm) or high cIMT (>0.86 mm), respectively. CV events and death from all causes were registered during a seven-year follow-up. RESULTS: Mean age, BMI and duration of diabetes were 68 years (range: 45-90), >30 kg/m2 and 15 years (range: 5-40), respectively. Patients with increased cIMT were older, suffered from a lower estimated glomerular filtration rate (eGFR), peripheral atherosclerosis and plaque presence in either carotid artery. Increased BMI (beta= -0.29, p = .01), lower eGFR (beta = 0.353, p = .003) and male gender (beta= -0.339, p = .005) were found to predict increased cIMT. Predictors of all-cause mortality in Cox proportional hazard models were low eGFR and high cIMT with HR = 0.96 (CI = 0.94-0.98), p < .001 and HR = 2.9 (CI = 1.03-7.99), p = .04, respectively. The risk of future CV event was determined by albuminuria and cIMT with HR = 1 (CI = 1.0-1.0), p < .001 and HR = 2.04 (CI = 1.1-3.78), p = .02, respectively. Patients with high cIMT presented significantly higher all-cause mortality and a new CV event (p = .005/p = .018, respectively). CONCLUSIONS: cIMT is a strong and independent predictor of CV morbidity and mortality, and should be considered a valuable tool for the stratification of CV risk in patients with CKD and DM2.

Role of CYP4F2, CYP2C19, and CYP1A2 polymorphisms on acenocoumarol pharmacogenomic algorithm accuracy improvement in the Greek population: need for sub-phenotype analysis.

BACKGROUND: We have earlier developed a pharmacogenomic algorithm for acenocoumarol dose prediction in Greek patients that included CYP2C9/VKORC1 genetic information. This study aims at analyzing the potential effect of CYP4F2, CYP2C19, and CYP1A2 gene polymorphisms on acenocoumarol dose requirements and at further improving the Greek-specific pharmacogenomic algorithm. METHODS: A total of 205 Greek patients taking acenocoumarol (140 who reached and 65 who did not reach stable dose), participants of acenocoumarol EU-PACT trial, were included in the study. CYP4F2, CYP2C19, and CYP1A2 polymorphisms were genotyped by use of the PCR-RFLP method. All patients were previously genotyped for CYP2C9/VKORC1 polymorphisms. RESULTS: In the pooled sample, CYP4F2, CYP2C19, and CYP1A2 polymorphisms do not affect independently acenocoumarol dose requirements. For CYP4F2, significant effects were found on patients' ability to reach stable dose and on acenocoumarol dose requirements when CYP2C9/VKORC1 sub-phenotypes were analyzed. Specifically, when the patients were stratified according to their CYP2C9/VKORC1 functional bins, in sensitive responders, CYP4F2*3 allele carriers (CYP4F2 *1/*3 and *3/*3 genotypes) were more frequent in the patient group who reached stable dose (p=0.049). Additionally, in CYP2C9 intermediate metabolizers (IMs), after adjusting for age, weight, and VKORC1 genotypes, CYP4F2 genotypes were significantly associated with acenocoumarol stable dose (ß: 0.07; 95% CI: 0.006-0.134; p=0.033). CONCLUSIONS: CYP4F2 gene shows a prominent weak association with acenocoumarol dose requirements. Sub-phenotype analysis is potentially important in determining additional gene polymorphisms that are associated with acenocoumarol dose requirements.

Epigenetics-by-Sex Interaction for Coronary Artery Disease Risk Conferred by the Cystathionine γ-Lyase Gene Promoter Methylation.

Coronary artery disease (CAD) is a major global health burden whereby gene-by-environment-by-sex interactions play an important role. Coronary artery bypass graft (CABG) surgery involves patients with well-documented and severe CAD. Hence, the study of CAD in a context of the CABG surgery serves as an advantageous model for disease phenotype ascertainment and genetic association studies. We report here new observations from a case-control genetic association study on promoter methylation of the cystathionine γ-lyase (CTH) gene and its association with CAD. To the best of our knowledge, this is the first clinical study to show the DNA methylation status of the CTH promoter in relation to this clinical phenotype. CTH encodes for the hydrogen sulfide generating enzyme named CSE in the endothelium that is mechanistically highly relevant for CAD. In a sample of 334 subjects from Greece (178 cases with CAD and who underwent CABG, and 156 controls), CTH promoter methylation was analyzed using a SYBR Green-based quantitative methylation-specific polymerase chain reaction. We found increased methylation in CTH promoter in cases (19.1%) compared to controls (10.3%) (p = 0.024). Gene-by-sex analysis sustained the significant association in men (p = 0.032) but not in women (p = 0.884). By using multivariate analyses after controlling for potential confounders such as smoking, age, and gender, we found that increased CTH gene promoter methylation was associated with CAD in the total sample (odds ratio [OR] = 2.163, 95% confidence interval [CI] 1.038-4.506, p = 0.039) and in men (OR = 2.418, 95% CI 1.048-5.581, p = 0.039) but not in women (OR = 0.542, 95% CI 0.094-3.140, p = 0.495). These observations collectively warrant further precision medicine and biomarker research to examine the CTH methylation status as a putative epigenetic regulator of CAD risk in larger and independent samples.

Matrix Gla protein T-138C polymorphism is associated with carotid intima media thickness and predicts mortality in patients with diabetic nephropathy.

AIMS: We sought to determine the predictive value of Matrix Gla Protein MGP T-138C polymorphism in relation to all-cause mortality, cardiovascular mortality and cardiovascular events in patients with diabetic nephropathy (DN). METHODS: MGP T-138C polymorphism was assessed in 40 diabetic patients without nephropathy and 118 patients at different stages of DN, including patients on hemodialysis. Measurement of carotid intima-media thickness (cIMT) was performed using real-time B-mode ultrasonography. Plasma levels of dephoshorylated uncarboxylated Matrix Gla Protein (dp-ucMGP) were determined in a subgroup of 67 patients by ELISA. Mortality and cardiovascular events were assessed during a 7year follow-up. RESULTS: TT homozygotes for the MGP T-138C polymorphism had higher values of cIMT compared to combined TC and CC genotypes (P=0.006) whereas no association was observed between cIMT and dp-ucMGP levels. MGP T-138C polymorphism was a strong independent predictor of cIMT (P<0.0001), after adjustment for several well-known atherosclerosis risk factors. Patients with TT genotype presented a significantly higher all-cause and cardiovascular mortality risk compared to patients with TC and CC genotypes (P=0.01 and P=0.04 respectively), after adjustment for several traditional risk factors. CONCLUSIONS: MGP T-138C polymorphism is a strong and independent predictor of increased cIMT as well as all-cause and cardiovascular mortality in DN patients.

Endothelial nitric oxide synthase gene polymorphisms are associated with sensitization to seasonal aeroallergens in asthmatic children.

BACKGROUND: Childhood asthma phenotype is the consequence of interaction between environment and genetic factors. Nitric oxide (NO) formation is affected by polymorphisms in nitric oxide synthase (NOS) enzymes, which play a significant role as inflammatory factors in the airways. This study was undertaken to estimate the correlation of -786C>T and 894G>T polymorphisms of the eNOS gene with the sensitization of asthmatic children to common aeroallergens. METHODS: A total of 193 asthmatic children and 96 healthy controls, who were of Mediterranean origin, living in the same geographical area, were enrolled in the study. 894G>T and -786T/C polymorphisms of the eNOS gene were analyzed using a PCR-RFLP method. RESULTS: The 894GG genotype was more frequent (68.6%) in children with asthma sensitized to Oleaeuropaea than in those with asthma non-sensitized (43.0%) (P=0.004). Likewise, -786TT genotype frequency was higher in children with asthma sensitized to Oleaeuropaea (51.0%) than in those with asthma nonsensitized (31.7%) to this allergen (P=0.035). For the aeroallergens Parietariajudaica and mixed grass, the frequency of -786C allele carriage was associated with protection from sensitization to Parietariajudaica and mixed grass in asthmatic children (P=0.021 and P=0.017, respectively). In the healthy control group, the genotype frequencies for these polymorphisms were similar to genotype frequencies of children with asthma non-sensitized to these three specific aeroallergens. CONCLUSION: In children with asthma, 894G>T and -786T/C polymorphisms of the eNOS gene were correlated with sensitization to common seasonal aeroallergens.

A novel acenocoumarol pharmacogenomic dosing algorithm for the Greek population of EU-PACT trial.

AIM: To generate and validate a pharmacogenomic-guided (PG) dosing algorithm for acenocoumarol in the Greek population. To compare its performance with other PG algorithms developed for the Greek population. PATIENTS & METHODS: A total of 140 Greek patients participants of the EU-PACT trial for acenocoumarol, a randomized clinical trial that prospectively compared the effect of a PG dosing algorithm with a clinical dosing algorithm on the percentage of time within INR therapeutic range, who reached acenocoumarol stable dose were included in the study. RESULTS: CYP2C9 and VKORC1 genotypes, age and weight affected acenocoumarol dose and predicted 53.9% of its variability. EU-PACT PG algorithm overestimated acenocoumarol dose across all different CYP2C9/VKORC1 functional phenotype bins (predicted dose vs stable dose in normal responders 2.31 vs 2.00 mg/day, p = 0.028, in sensitive responders 1.72 vs 1.50 mg/day, p = 0.003, in highly sensitive responders 1.39 vs 1.00 mg/day, p = 0.029). The PG algorithm previously developed for the Greek population overestimated the dose in normal responders (2.51 vs 2.00 mg/day, p < 0.001). CONCLUSION: Ethnic-specific dosing algorithm is suggested for better prediction of acenocoumarol dosage requirements in patients of Greek origin.

Association of Plasma Adiponectin and Oxidized Low-Density Lipoprotein with Carotid Intima-Media Thickness in Diabetic Nephropathy.

AIMS: We sought to determine the association between levels of adiponectin and oxidized low-density lipoprotein (ox-LDL) in patients with diabetic nephropathy as well as their effect on carotid intima-media thickness (cIMT). METHODS: Adiponectin and ox-LDL were determined in 25 diabetic patients without nephropathy and 94 patients at different stages of diabetic nephropathy including subjects on hemodialysis. cIMT was measured using real-time B-mode ultrasonography. RESULTS: Plasma adiponectin levels increased significantly with severity of diabetic nephropathy (P = 0.002), on the contrary to ox-LDL which decreased with disease severity (P < 0.001). cIMT was significantly higher at late stages of diabetic nephropathy compared with early stages (P = 0.022). Adiponectin was a significant negative predictor of ox-LDL levels (ß = -5.45, P = 0.023), independently of confounding factors. There was no significant correlation between cIMT and adiponectin or ox-LDL either in the total sample population or according to disease staging. Cluster analysis showed that patients with the highest cIMT values, highest levels of adiponectin, and lowest levels of ox-LDL were included in one cluster and all assigned to stage 5 of diabetic nephropathy. CONCLUSIONS: There was no significant association between adiponectin or ox-LDL and cIMT and, therefore, other factors affecting this surrogate marker of cardiovascular disease in diabetic nephropathy should be sought.

Gene-gene interaction of µ-opioid receptor and GluR5 kainate receptor subunit is associated with smoking behavior in a Greek population: presence of a dose allele effect.

BACKGROUND: Components of nicotine reward system can potentially influence smoking behavior. The µ-opioid receptor (OPRM1) binds the endogenous opioid peptide ß-endorphin and mediates the reinforcing effects of nicotine, while the GluR5 kainate receptor subunit (encoded by GRIK1 gene), a binding site for known mediators of glutamate neurotransmission, potentially affects the glutaminergic system that is also indirectly implicated in the reward system. METHODS: In the present study, OPRM1 A118G and GRIK1 rs2832407C>A polymorphisms and their interactions were analyzed in 132 smoking initiators (SI) and 144 non-initiators (NI) of Greek origin, using the PCR-RFLP method. RESULTS: No differences were found in the genotype or allele distribution of OPRM1 A118G and GRIK1 rs2832407C>A between SI and NI. However, we found a significant interaction of OPRM1 A118G and GRIK1 rs2832407C>A genotypes associated with smoking initiation in a model adjusted for age, sex, BMI and type 2 diabetes mellitus (odds ratio=1.341, 95% CI 1.024-1.755, p=0.033). A dose effect of OPRM1 and GRIK1 variant alleles was present. Increased number of variant alleles (from 0 to 4) was associated with smoking initiation in the same adjusted model (odds ratio=1.537, 95% CI 1.030-2.293, p=0.036). CONCLUSIONS: Smoking phenotype is a complex interaction of genetic and environmental factors. In the present study, we have shown that gene-gene interaction of components of different systems associated with nicotine reinforcing effects, such as OPRM1 and GRIK1, rather than one gene polymorphism, is associated with smoking behavior.

New aspects on the metabolic role of intestinal microbiota in the development of atherosclerosis.

Gut microbiota remains a very interesting, yet largely unexplored ecosystem inside the human organism. The importance of this ecosystem for the physiology and the pathophysiology of the organism is being slowly unraveled. Recent studies reveal a connection between intestinal microbiota and atherosclerosis development. It seems that alterations in the function and composition of this bacterial population lead through complex mechanisms to a high risk for atherosclerosis. Although these mechanisms remain largely unknown, published studies show that microbiota can lead to atherosclerosis either by augmenting known risk factors or via other, more "direct" mechanisms. This review article summarizes the available literature regarding this matter.

No effect of CYP3A4 intron 6 C>T polymorphism (CYP3A4*22) on lipid-lowering response to statins in Greek patients with primary hypercholesterolemia.

BACKGROUND: Interindividual variability exists in statin lipid-lowering response, partially attributed to genetic factors. CYP3A4 intron 6 C>T polymorphism (CYP3A4*22 allele, rs35599367) has been recently identified and was associated with reduced CYP3A4 expression. We analyzed the association of CYP3A4*22 allele with response to atorvastatin and simvastatin. METHODS: A total of 416 statin-treated (207 atorvastatin- and 209 simvastatin-treated) adults with primary hypercholesterolemia were included in the study. Total cholesterol and low-density lipoprotein cholesterol were measured at baseline and on 6 months of treatment. CYP3A4*22 allele was analyzed with TaqMan assay. RESULTS: In the entire cohort population, 41 individuals carried CYP3A4*22 allele (18 in atorvastatin and 23 in simvastatin treatment). CYP3A4*22 allele was not associated with lipid-lowering response to atorvastatin or simvastatin. No sex-gene or statin dose-gene interaction was observed in either statin-treated patient cohort. CONCLUSIONS: The effect of CYP3A4*22 allele on lipid-lowering response to CYP3A metabolized statins, if present, can potentially be masked by relevant confounding or uncontrolled factors; therefore, further population-driven studies are required.

Bone grafts as carriers for local antibiotic delivery for the treatment and prevention of bone infections.

Osteomyelitis is a bone infection accompanied by inflammatory process, which can lead to destruction and bone necrosis. It is difficult to manage, and there are no commonly accepted guidelines. While most acute bone infections are usually successfully treated with intravenous antibiotics, chronic infections and infections in the presence of foreign materials usually require operative treatment with debridement, removal of metals, intravenous antibiotics, and very often local antibiotics. The aim of this study was to perform a systematic review of the existing literature concerning the use of bone grafts as carriers for local antibiotic delivery for the treatment and prevention of bone infections. According to the literature, antibiotic-loaded autologous bone grafts for the treatment of infected tibial nonunion is a good option (Grade-B recommendations). Although there are several studies concerning the use of antibiotic-loaded allogenic bone grafts in infected joint arthroplasty revisions, there is a lack of comparative studies (Grade-C recommendations). Studies concerning spinal fusion and spondylodiscitis are limited (Grade-I recommendations).

Vitamin D receptor ApaI a allele is associated with better childhood asthma control and improvement in ability for daily activities.

Vitamin D levels have been suggested as a marker of disease severity in asthmatic children. Our aim was to investigate possible associations between the vitamin D receptor (VDR) FokI, BsmI, ApaI, and TaqI polymorphisms and asthma susceptibility and control in children. 127 Greek children with asthma and 91 healthy controls were genotyped for VDR FokI, BsmI ApaI, and TaqI polymorphisms using Sequenom MassARRAY iPLEX platform. Asthma control was assessed according to the Global Initiative for Asthma guidelines (GINA) and Childhood Asthma Control Test (C-ACT) and, for the first time, tested for its possible association with VDR SNPs. Asthmatic children were grouped as "controlled (n=49)", "partially controlled (n=38)," and "uncontrolled (n=40)," according to GINA classification. No association was found between VDR polymorphisms and asthma prevalence. Asthmatic children with the VDR ApaI aa genotype had significantly higher C-ACT score compared with asthmatic children carrying the AA/AC VDR ApaI genotypes (p=0.011). The frequency of VDR ApaI aa genotype was significantly higher in controlled asthma group (n=92) than uncontrolled asthma group (n=35), according to C-ACT (24.5% vs 0.0%, p<0.001) and GINA (32.7% vs 7.5%, p=0.001). Also, VDR ApaI aa genotype was negatively associated with limitation in daily activities because of asthma (p=0.004). VDR ApaI aa genotype was positively associated with well-controlled asthma according to GINA and C-ACT questionnaire and negatively associated with decreased limitation in daily activities in asthmatic children, further supporting the importance of Vitamin D pathway in asthma.

Frequency of CYP450 enzyme gene polymorphisms in the Greek population: review of the literature, original findings and clinical significance.

The cytochrome P450 (CYP450) enzyme family is involved in the oxidative metabolism of many therapeutic drugs and various endogenous substrates. These enzymes are highly polymorphic. Prevalence of CYP450 enzyme gene polymorphisms vary among different populations and substantial inter- and intra-ethnic variability in frequency of CYP450 enzyme gene polymorphisms has been reported. This paper provides an overview and investigation of CYP450 genotypic and phenotypic reports published in the Greek population.

Impact of CYP3A5 Gene Polymorphism on Efficacy of Simvastatin.

BACKGROUND: One of the promises of human genetics is individualized therapy. Therefore, we evaluated the impact of CYP3A5 gene polymorphism on the effectiveness of simvastatin (a HMG-CoA reductase inhibitor). METHODS: Patients (n = 191) with hypercholesterolemia were treated with simvastatin for at least 6 months and were genotyped for the CYP3A5 polymorphism. RESULTS: The frequency of CYP3A5 polymorphism was 0.5% for WT (wild-type), 15.6% for HT (heterozygous, expressors) and 83.9% for HM (homozygous, non-expressors). Differences in lipid profile before and after dose-response of simvastatin treatment were described as % difference {[(variable after-variable before)/variable before]*100}. There was a trend towards the decrease of low density lipoprotein cholesterol (LDL-C) in HT individuals who had a -35.2% reduction with a dose of 20 mg simvastatin and HM individuals who had a slightly higher decrease (-37.5%) despite the lower dose of simvastatin (10 mg, p = 0.07). Furthermore, HT genotype individuals had significantly higher than expected (6-8%) LDL-C % difference between 20 and 40 mg of simvastatin (-35.2 vs -49.2%, p = 0.037). In individuals with HM genotype a significant LDL-C % difference was found between 10 and 40 mg of simvastatin (-37.5 vs -48.4%, p = 0.023). CONCLUSION: The individuals with HM polymorphism display a trend towards higher LDL-C reductions compared with HT polymorphism. Within the same genotype, differences between doses were also observed. These findings need to be confirmed in larger studies.

Lack of association of the p450 oxidoreductase *28 single nucleotide polymorphism with the lipid-lowering effect of statins in hypercholesterolemic patients.

BACKGROUND AND OBJECTIVE: Inter-individual variability exists in the statin (HMG-CoA reductase inhibitor) lipid-lowering response, which is partially attributed to genetic factors. The polymorphic enzyme P450 oxidoreductase (POR) transfers electrons from nicotinamide adenine dinucleotide phosphate (NADPH) to cytochrome P450 (CYP) 3A enzymes, which metabolize atorvastatin and simvastatin. The POR*28 allele is associated with increased activity of CYP3A enzymes. We analyzed the association of the POR*28 allele with response to atorvastatin and simvastatin. METHODS: A total of 207 atorvastatin-treated adults were included in the study. An independent population of 210 simvastatin-treated adults served as a replication cohort. Total cholesterol (TChol) and low-density lipoprotein cholesterol (LDL-C) were measured at baseline and after 6 months of treatment. The POR*28 allele was analyzed with a TaqMan(®) assay. RESULTS: The POR*28 allele was associated with a non-significant trend towards lower percentage mean reduction of TChol (-35.5 % in *1/*1, -33.7 % in *1/*28, and -29.5 % in *28/*28 individuals) and LDL-C (-42.6 % in *1/*1, -41.7 % in *1/*28, and -37.8 % in *28/*28 individuals) in response to atorvastatin. This trend was not observed in the replication cohort of simvastatin-treated patients. No sex-gene interaction was observed regarding the effect of the POR*28 allele on the statin lipid-lowering response in either statin-treated patient cohort. CONCLUSION: The POR*28 allele was not associated with the lipid-lowering effect of atorvastatin and the results were replicated in an independent simvastatin-treated population. The hypothesized effect of the POR*28 allele on the lipid-lowering response to CYP3A-metabolized statins can potentially be masked by relevant confounding or uncontrolled factors; therefore, further studies in different populations are required.

Association of functional VKORC1 promoter polymorphism with occurrence and clinical aspects of ischemic stroke in a Greek population.

Genetic factors are considered to play an important role in determining the susceptibility to the occurrence, clinical course, and functional outcome of an acute ischemic stroke (IS). Undercarboxylation of specific vitamin K-dependent proteins, due to genetic polymorphisms of VKORC1, can affect both vascular calcification and thrombogenicity. We sought to determine the association of VKORC1 -1639G > A polymorphism with IS incidence, age of onset, severity of disease, and functional outcome after an acute IS. VKORC1 -1639G > A polymorphism was determined in 145 consecutive patients with first ever IS and 145 age- and sex-matched control subjects of Greek Caucasian origin using PCR-RFLP. Stroke severity and functional outcome were assessed on admission and at one month after stroke, respectively. Frequency of VKORC1 -1639G > A genotypes did not differ between IS patients and controls (OR = 1.12, P = 0.51). Moreover, carriage of the A allele was not associated with age of stroke onset, severity of disease (Scandinavian stroke scale score 32.2 versus 32.9, resp., P = 0.96), or poor outcome at 1 month post-stroke (52.9 versus 64.4%, resp., P = 0.31). In conclusion, VKORC1 -1639G > A polymorphism is not a genetic determinant of IS occurrence, age of onset, severity, or functional outcome of disease in a Greek population.

A randomized trial of genotype-guided dosing of acenocoumarol and phenprocoumon.

BACKGROUND: Observational evidence suggests that the use of a genotype-guided dosing algorithm may increase the effectiveness and safety of acenocoumarol and phenprocoumon therapy. METHODS: We conducted two single-blind, randomized trials comparing a genotype-guided dosing algorithm that included clinical variables and genotyping for CYP2C9 and VKORC1 with a dosing algorithm that included only clinical variables, for the initiation of acenocoumarol or phenprocoumon treatment in patients with atrial fibrillation or venous thromboembolism. The primary outcome was the percentage of time in the target range for the international normalized ratio (INR; target range, 2.0 to 3.0) in the 12-week period after the initiation of therapy. Owing to low enrollment, the two trials were combined for analysis. The primary outcome was assessed in patients who remained in the trial for at least 10 weeks. RESULTS: A total of 548 patients were enrolled (273 patients in the genotype-guided group and 275 in the control group). The follow-up was at least 10 weeks for 239 patients in the genotype-guided group and 245 in the control group. The percentage of time in the therapeutic INR range was 61.6% for patients receiving genotype-guided dosing and 60.2% for those receiving clinically guided dosing (P=0.52). There were no significant differences between the two groups for several secondary outcomes. The percentage of time in the therapeutic range during the first 4 weeks after the initiation of treatment in the two groups was 52.8% and 47.5% (P=0.02), respectively. There were no significant differences with respect to the incidence of bleeding or thromboembolic events. CONCLUSIONS: Genotype-guided dosing of acenocoumarol or phenprocoumon did not improve the percentage of time in the therapeutic INR range during the 12 weeks after the initiation of therapy. (Funded by the European Commission Seventh Framework Programme and others; EU-PACT ClinicalTrials.gov numbers, NCT01119261 and NCT01119274.).