Rivaroxaban: a novel oral anticoagulant for the prevention and treatment of several thrombosis-mediated conditions.

The development of rivaroxaban (XARELTO®) is an important new medical advance in the field of oral anticoagulation. Thrombosis-mediated conditions constitute a major burden for patients, healthcare systems, and society. For more than 60 years, the prevention and treatment of these conditions have been dominated by oral vitamin K antagonists (such as warfarin) and the injectable heparins. Thrombosis can lead to several conditions, including deep vein thrombosis, pulmonary embolism, myocardial infarction, stroke, and/or death. Prevention and treatment of thrombosis with an effective, convenient-to-use oral anticoagulant with a favorable safety profile is critical, especially in an aging society in which the risk of thrombosis, and the potential for bleeding complications, is increasing. Rivaroxaban acts to prevent and treat thrombosis by potently inhibiting coagulation Factor Xa in the blood. Factor Xa converts prothrombin to thrombin, which initiates the formation of blood clots by converting fibrinogen to clot-forming fibrin and leads to platelet activation. After a large and novel clinical development program in over 75,000 patients to date, rivaroxaban has received approval for multiple indications in the United States, European Union, and other countries worldwide to prevent and treat several thrombosis-mediated conditions. This review will highlight some of the unique aspects of the rivaroxaban development program.

Rivaroxaban for the prevention of venous thromboembolism after hip or knee arthroplasty. Pooled analysis of four studies.

Four phase III studies compared oral rivaroxaban with subcutaneous enoxaparin for the prevention of venous thromboembolism (VTE) after total hip or knee arthroplasty (THA or TKA). A pooled analysis of these studies compared the effect of rivaroxaban with enoxaparin on symptomatic VTE plus all-cause mortality and bleeding events, and determined whether these effects were consistent in patient subgroups. Patients (N=12,729) aged ≥18 years and scheduled for elective THA or TKA received rivaroxaban 10 mg once daily or enoxaparin 40 mg once daily or 30 mg every 12 hours. The composite of symptomatic VTE and all-cause mortality, the prespecified primary efficacy endpoint and adjudicated bleeding events were analysed in the day 12± 2 active treatment pool. Subgroup analyses of these outcomes were performed over the total treatment period. In the day 12± 2 pool, the primary efficacy endpoint occurred in 29/6,183 patients receiving rivaroxaban (0.5%) versus 60/6,200 patients receiving enoxaparin (1.0%; p=0.001). Major bleeding occurred in 21 (0.3%) versus 13(0.2%) patients, p=0.23; major plus non-major clinically relevant bleeding in 176(2.8%) versus 152 (2.5%) patients, p=0.19; and any bleeding in 409 (6.6%) versus 384 (6.2%) patients, p=0.38, respectively. The reduction of symptomatic VTE plus all-cause mortality was consistent across prespecified subgroups (age, gender, body weight, creatinine clearance) in the total treatment period. Compared with enoxaparin regimens, rivaroxaban reduces the composite of symptomatic VTE and all-cause mortality after elective THA or TKA, with a small increase in bleeding, no signs of compromised liver safety and fewer serious adverse events.

Development and validation of a risk-score model for subjects with impaired glucose tolerance for the assessment of the risk of type 2 diabetes mellitus-The STOP-NIDDM risk-score.

AIMS: To develop a risk-score model, based on available clinical data to assess absolute risk of type 2 diabetes among people with impaired glucose tolerance (IGT). METHODS: Data from the study to prevent non-insulin dependent diabetes mellitus (STOP-NIDDM) investigating acarbose treatment in individuals with IGT were used to develop multivariable Cox proportional hazards model for the time to onset of diabetes. The final model equation was externally validated using data from the Finnish Cardiovascular Risk Factor (FINRISK) population. RESULTS: The risk-score model included the variables acarbose treatment, gender, serum triglyceride level, waist circumference, fasting plasma glucose, height, history of cardiovascular disease (CVD) and hypertension. The final model yielded an area under the receiver-operating-characteristic curve (AUC(ROC)) of 0.64 when applied to people with IGT in the STOP-NIDDM, and 0.84 and 0.90 when applied to FINRISK population with IGT alone and IGT and normal glucose tolerance combined, respectively; AUC(ROC) is a measure of the discriminatory power of the model (1, perfect discrimination). CONCLUSIONS: The STOP-NIDDM risk-score is a simple and validated tool that can identify high-risk individuals with IGT who would benefit most from type 2 diabetes or CVD prevention strategies, such as lifestyle management or early acarbose treatment.

Metabolic syndrome and its single traits as risk factors for diabetes in people with impaired glucose tolerance: the STOP-NIDDM trial.

The STOP-NIDDM trial was an international, double-blind, placebo-controlled randomised study in people with impaired glucose tolerance (IGT). They were treated with an alpha-glucosidase inhibitor, acarbose, to prevent diabetes; the overall number needed to treat (NNT) was 11. In a secondary analysis, we considered the impact of single traits and overall metabolic syndrome (MetS) respectively on risk of diabetes and NNT respectively. In all, there were 1,368 patients. They were followed up for 3.3 years, and the prevalence of MetS was 61%. Multivariate analysis revealed treatment group 2-hour (post-challenge) plasma glucose, glycosylated haemoglobin (HbA1C), triglycerides and leukocyte count as independent predictors. The annual incidence of diabetes in the placebo group with MetS was 18.7% vs. 11.2% in patients without MetS; the corresponding figures in the acarbose group were 13.5% and 9.4%, respectively. The NNT in patients was 5.8 in patients with MetS and 16.5 in those without MetS. In conclusion, most single traits and overall MetS label a very high-risk group in people with IGT. People with MetS reach a NNT to prevent development of new diabetes with acarbose of 5.8.

Long-term improvement of metabolic control by acarbose in type 2 diabetes patients poorly controlled with maximum sulfonylurea therapy.

BACKGROUND AND OBJECTIVE: Multiple oral therapies are required long term for the majority of patients with type 2 diabetes mellitus to achieve acceptable glycaemic levels; alternatively, insulin therapy has to be initiated. This study investigated the addition of acarbose to maximum doses of sulfonylurea in very poorly controlled type 2 diabetes patients and assessed its effect in delaying further glycaemic deterioration. STUDY DESIGN: In this 78-week, double-blind, placebo-controlled European study, patients were randomised to receive acarbose, titrated to a maximum dose of 100mg three times daily, or matching placebo. Concomitant sulfonylurea treatment (glibenclamide/gliclazide) was to remain unchanged throughout the study. A sample size of 171 patients per treatment arm was calculated. The primary efficacy analysis was intention to treat. METHODS: The change in glycosylated haemoglobin (HbA(1c)) levels from baseline to the end of the study was regarded as the primary efficacy variable. Patients whose HbA(1c) levels increased above 10.5% on two consecutive visits terminated the study prematurely because of insulin administration. Secondary efficacy variables included the changes in blood glucose and C-peptide, both at fasting and at the 1h-postprandial level. PATIENTS: A total of 330 patients (acarbose 164, placebo 166) were valid for the efficacy analysis. Patients were generally overweight (body mass index 29.0 kg/m(2)) and showed very poor metabolic control (HbA(1c) >9%, fasting blood glucose >200 mg/dL, and 1h-postprandial blood glucose >300 mg/dL). RESULTS: Acarbose significantly improved HbA(1c) levels compared with placebo (least square mean [LS-mean] difference -0.54%, 95% CI -0.86 to -0.22; p = 0.001). A number of patients had to discontinue the study prematurely because of insulin administration (24.5% in the placebo and 14.2% in the acarbose group). There was a significant LS-mean difference of -14.8 mg/dL (p = 0.0195) in fasting blood glucose levels and highly significant differences in 1h-postprandial blood glucose (LS-mean difference -33.4 mg/dL, p < 0.0001) and in the rise in blood glucose from fasting to 1h-postprandial (LS-mean difference -19.6 mg/dL, p = 0.0001), all in favour of acarbose. Acarbose was shown to have a good safety profile and was generally well tolerated. CONCLUSION: Acarbose was shown to have the potential to delay further deterioration of glucose control in type 2 diabetes patients who are very poorly controlled with maximum sulfonylurea doses.