Abelacimab for Prevention of Venous Thromboembolism.

BACKGROUND: The role of factor XI in the pathogenesis of postoperative venous thromboembolism is uncertain. Abelacimab is a monoclonal antibody that binds to factor XI and locks it in the zymogen (inactive precursor) conformation. METHODS: In this open-label, parallel-group trial, we randomly assigned 412 patients who were undergoing total knee arthroplasty to receive one of three regimens of abelacimab (30 mg, 75 mg, or 150 mg) administered postoperatively in a single intravenous dose or to receive 40 mg of enoxaparin administered subcutaneously once daily. The primary efficacy outcome was venous thromboembolism, detected by mandatory venography of the leg involved in the operation or objective confirmation of symptomatic events. The principal safety outcome was a composite of major or clinically relevant nonmajor bleeding up to 30 days after surgery. RESULTS: Venous thromboembolism occurred in 13 of 102 patients (13%) in the 30-mg abelacimab group, 5 of 99 patients (5%) in the 75-mg abelacimab group, and 4 of 98 patients (4%) in the 150-mg abelacimab group, as compared with 22 of 101 patients (22%) in the enoxaparin group. The 30-mg abelacimab regimen was noninferior to enoxaparin, and the 75-mg and 150-mg abelacimab regimens were superior to enoxaparin (P<0.001). Bleeding occurred in 2%, 2%, and none of the patients in the 30-mg, 75-mg, and 150-mg abelacimab groups, respectively, and in none of the patients in the enoxaparin group. CONCLUSIONS: This trial showed that factor XI is important for the development of postoperative venous thromboembolism. Factor XI inhibition with a single intravenous dose of abelacimab after total knee arthroplasty was effective for the prevention of venous thromboembolism and was associated with a low risk of bleeding. (Funded by Anthos Therapeutics; ANT-005 TKA EudraCT number, 2019-003756-37.).

Trajectories of Changes in Renal Function in Patients with Acute Heart Failure.

BACKGROUND: Changes in renal function have been associated with differential outcomes in patients with acute heart failure (HF). However, individual trajectories of changes in renal function are unknown, and it is unclear whether they relate to different clinical characteristics and clinical outcomes. Our aim was to investigate the prognostic importance of individual trajectories of change in renal function in acute HF. METHODS: This was a retrospective, observational analysis from the double-blind, randomized, placebo-controlled PROTECT trial in patients with acute HF. We identified and internally validated 8 different renal trajectories among 1897 patients by visual inspection of inhospital serum creatinine changes. The primary outcome measure was all-cause mortality at 180 days. Mean age was 70 ± 12 years; 70% were male, and mean baseline estimated glomerular filtration rate was 49.0 mL/min/1.73m2. RESULTS: A total of 8 different trajectories was established. The most prevalent trajectories were an inhospital bump (19.0%), a sustained increase (17.6%) and a dip (14.5%) in serum creatinine. Overall, the clinical characteristics of patients in different trajectories were remarkably similar. Crude 180-day mortality rates ranged from 12.0% in the trajectory, with no significant changes to 18.3% in the trajectory of sustained increase without significant differences. Overall, after multivariable adjustment, there was no trajectory of changes in renal function that was associated with significantly better or worse outcomes. CONCLUSIONS: Trajectories of changes in renal function in acute HF differ considerably on the patient level. Despite these differences, clinical characteristics and outcomes were similar, therefore, questioning the prognostic importance of changes in renal function in acute HF.

Clinical Correlates and Prognostic Value of Proenkephalin in Acute and Chronic Heart Failure.

BACKGROUND: Proenkephalin (pro-ENK) has emerged as a novel biomarker associated with both renal function and cardiac function. However, its clinical and prognostic value have not been well evaluated in symptomatic patients with heart failure. METHODS AND RESULTS: The association between pro-ENK and markers of renal function was evaluated in 95 patients with chronic heart failure who underwent renal hemodynamic measurements, including renal blood flow (RBF) and glomerular filtration rate (GFR) with the use of 131I-Hippuran and 125I-iothalamate clearances, respectively. The association between pro-ENK and clinical outcome in acute heart failure was assessed in another 1589 patients. Pro-ENK was strongly correlated with both RBF (P < .001) and GFR (P < .001), but not with renal tubular markers. In the acute heart failure cohort, pro-ENK was a predictor of death through 180 days, heart failure rehospitalization through 60 days, and death or cardiovascular or renal rehospitalization through day 60 in univariable analyses, but its predictive value was lost in a multivariable model when other renal markers were entered in the model. CONCLUSIONS: In patients with chronic and acute heart failure, pro-ENK is strongly associated with glomerular function, but not with tubular damage. Pro-ENK provides limited prognostic information in patients with acute heart failure on top of established renal markers.

Identifying Subpopulations with Distinct Response to Treatment Using Plasma Biomarkers in Acute Heart Failure: Results from the PROTECT Trial : Differential Response in Acute Heart Failure.

BACKGROUND: Over the last 50 years, clinical trials of novel interventions for acute heart failure (AHF) have, with few exceptions, been neutral or shown harm. We hypothesize that this might be related to a differential response to pharmacological therapy. METHODS: We studied the magnitude of treatment effect of rolofylline across clinical characteristics and plasma biomarkers in 2033 AHF patients and derived a biomarker-based responder sum score model. Treatment response was survival from all-cause mortality through day 180. RESULTS: In the overall study population, rolofylline had no effect on mortality (HR 1.03, 95% CI 0.82-1.28, p = 0.808). We found no treatment interaction across clinical characteristics, but we found interactions between several biomarkers and rolofylline. The biomarker-based sum score model included TNF-R1α, ST2, WAP four-disulfide core domain protein HE4 (WAP-4C), and total cholesterol, and the score ranged between 0 and 4. In patients with score 4 (those with increased TNF-R1α, ST2, WAP-4C, and low total cholesterol), treatment with rolofylline was beneficial (HR 0.61, 95% CI 0.40-0.92, p = 0.019). In patients with score 0, treatment with rolofylline was harmful (HR 5.52, 95% CI 1.68-18.13, p = 0.005; treatment by score interaction p < 0.001). Internal validation estimated similar hazard ratio estimates (0 points: HR 5.56, 95% CI 5.27-7-5.87; 1 point: HR 1.31, 95% CI 1.25-1.33; 2 points: HR 0.75, 95% CI 0.74-0.76; 3 points: HR 1.13, 95% CI 1.11-1.15; 4 points, HR 0.61, 95% CI 0.61-0.62) compared to the original data. CONCLUSION: Biomarkers are superior to clinical characteristics to study treatment heterogeneity in acute heart failure.

Plasma Neutrophil Gelatinase-Associated Lipocalin and Predicting Clinically Relevant Worsening Renal Function in Acute Heart Failure.

The aim of this study was to evaluate the ability of Neutrophil Gelatinase-Associated Lipocalin (NGAL) to predict clinically relevant worsening renal function (WRF) in acute heart failure (AHF). Plasma NGAL and serum creatinine changes during the first 4 days of admission were investigated in 1447 patients hospitalized for AHF and enrolled in the Placebo-Controlled Randomized Study of the Selective A1Adenosine Receptor Antagonist Rolofylline for Patients Hospitalized with Acute Decompensated Heart Failure and Volume Overload to Assess Treatment Effect on Congestion and Renal Function (PROTECT) study. WRF was defined as serum creatinine rise ≥ 0.3 mg/dL through day 4. Biomarker patterns were described using linear mixed models. WRF developed in 325 patients (22%). Plasma NGAL did not rise earlier than creatinine in patients with WRF. After multivariable adjustment, baseline plasma NGAL, but not creatinine, predicted WRF. AUCs for WRF prediction were modest (<0.60) for all models. NGAL did not independently predict death or rehospitalization (p = n.s.). Patients with WRF and high baseline plasma NGAL had a greater risk of death, and renal or cardiovascular rehospitalization by 60 days than patients with WRF and a low baseline plasma NGAL (p for interaction = 0.024). A rise in plasma NGAL after baseline was associated with a worse outcome in patients with WRF, but not in patients without WRF (p = 0.007). On the basis of these results, plasma NGAL does not provide additional, clinically relevant information about the occurrence of WRF in patients with AHF.

Diuretic response in acute heart failure: clinical characteristics and prognostic significance.

AIM: Diminished diuretic response is common in patients with acute heart failure, although a clinically useful definition is lacking. Our aim was to investigate a practical, workable metric for diuretic response, examine associated patient characteristics and relationships with outcome. METHODS AND RESULTS: We examined diuretic response (defined as Δ weight kg/40 mg furosemide) in 1745 hospitalized acute heart failure patients from the PROTECT trial. Day 4 response was used to allow maximum differentiation in responsiveness and tailoring of diuretic doses to clinical response, following sensitivity analyses. We investigated predictors of diuretic response and relationships with outcome. The median diuretic response was -0.38 (-0.80 to -0.13) kg/40 mg furosemide. Poor diuretic response was independently associated with low systolic blood pressure, high blood urea nitrogen, diabetes, and atherosclerotic disease (all P < 0.05). Worse diuretic response independently predicted 180-day mortality (HR: 1.42; 95% CI: 1.11-1.81, P = 0.005), 60-day death or renal or cardiovascular rehospitalization (HR: 1.34; 95% CI: 1.14-1.59, P < 0.001) and 60-day HF rehospitalization (HR: 1.57; 95% CI: 1.24-2.01, P < 0.001) in multivariable models. The proposed metric-weight loss indexed to diuretic dose-better captures a dose-response relationship. Model diagnostics showed diuretic response provided essentially the same or slightly better prognostic information compared with its individual components (weight loss and diuretic dose) in this population, while providing a less biased, more easily interpreted signal. CONCLUSIONS: Worse diuretic response was associated with more advanced heart failure, renal impairment, diabetes, atherosclerotic disease and in-hospital worsening heart failure, and predicts mortality and heart failure rehospitalization in this post hoc, hypothesis-generating study.

Rolofylline, an adenosine A1-receptor antagonist, in acute heart failure.

BACKGROUND: Worsening renal function, which is associated with adverse outcomes, often develops in patients with acute heart failure. Experimental and clinical studies suggest that counterregulatory responses mediated by adenosine may be involved. We tested the hypothesis that the use of rolofylline, an adenosine A1-receptor antagonist, would improve dyspnea, reduce the risk of worsening renal function, and lead to a more favorable clinical course in patients with acute heart failure. METHODS: We conducted a multicenter, double-blind, placebo-controlled trial involving patients hospitalized for acute heart failure with impaired renal function. Within 24 hours after presentation, 2033 patients were randomly assigned, in a 2:1 ratio, to receive daily intravenous rolofylline (30 mg) or placebo for up to 3 days. The primary end point was treatment success, treatment failure, or no change in the patient's clinical condition; this end point was defined according to survival, heart-failure status, and changes in renal function. Secondary end points were the post-treatment development of persistent renal impairment and the 60-day rate of death or readmission for cardiovascular or renal causes. RESULTS: Rolofylline, as compared with placebo, did not provide a benefit with respect to the primary end point (odds ratio, 0.92; 95% confidence interval, 0.78 to 1.09; P=0.35). Persistent renal impairment developed in 15.0% of patients in the rolofylline group and in 13.7% of patients in the placebo group (P=0.44). By 60 days, death or readmission for cardiovascular or renal causes had occurred in similar proportions of patients assigned to rolofylline and placebo (30.7% and 31.9%, respectively; P=0.86). Adverse-event rates were similar overall; however, only patients in the rolofylline group had seizures, a known potential adverse effect of A1-receptor antagonists. CONCLUSIONS: Rolofylline did not have a favorable effect with respect to the primary clinical composite end point, nor did it improve renal function or 60-day outcomes. It does not show promise in the treatment of acute heart failure with renal dysfunction. (Funded by NovaCardia, a subsidiary of Merck; ClinicalTrials.gov numbers, NCT00328692 and NCT00354458.).

Early dyspnoea relief in acute heart failure: prevalence, association with mortality, and effect of rolofylline in the PROTECT Study.

AIMS: Dyspnoea and pulmonary and/or peripheral congestion are the most frequent manifestations of acute heart failure (AHF) and are important targets for therapy. We have assessed changes in dyspnoea, their relationship with mortality, and the effects of the adenosine A1 receptor antagonist rolofylline on these endpoints in patients enrolled in the PROTECT trial. METHODS AND RESULTS: PROTECT was a prospective, double-blind, placebo-controlled study assessing the effect of rolofylline in patients hospitalized for AHF with dyspnoea, fluid overload, increased plasma natriuretic peptides, and mild-to-moderate renal dysfunction. Early dyspnoea relief, prospectively defined as moderately or markedly better dyspnoea at both 24 and 48 h after the start of study drug administration, occurred in 49.8% of the patients. Early dyspnoea relief was associated with greater weight loss and with reduced mortality at Days 14 and 30 [hazard ratio (HR) 0.28, 95% confidence interval (CI): 0.15, 0.50; and 0.35, 95% CI: 0.22, 0.55, respectively]. Rolofylline administration was associated with an increase in the proportion of patients showing early dyspnoea relief (HR 1.30; 95% CI: 1.08, 1.57) and with a numerically lower mortality at 14 and 30 days, largely driven by the mortality due to HF [at 30 days, HR (95% CI, P-value): 0.65 (0.38-1.10, P= 0.107)]. Rolofylline did not reduce episodes of in-hospital worsening HF or post-discharge re-admissions, nor did it improve survival at 60 or 180 days. CONCLUSION: The present analysis from PROTECT demonstrated that more weight loss was associated with early dyspnoea relief and reduced short-term mortality.

Efficacy and safety after cessation of treatment with the cholesteryl ester transfer protein inhibitor anacetrapib (MK-0859) in patients with primary hypercholesterolemia or mixed hyperlipidemia.

This report describes the lipid and safety data collected during an off-drug period that followed 8 weeks of treatment with the cholesteryl ester transfer protein inhibitor, anacetrapib (ANA). A total of 589 patients with primary hypercholesterolemia or mixed hyperlipidemia were randomized to placebo, atorvastatin (ATV) 20 mg, and varying doses of ANA, provided as monotherapy or coadministered with ATV 20 mg daily. Patients were treated for 8 weeks, followed by an 8-week follow-up period, during which ANA was switched to placebo. At week 16 (8 weeks after ANA was stopped), persistent reductions in low-density lipoprotein cholesterol (LDL-C) were evident for the monotherapy groups receiving ANA 150 and 300 mg (-9.3% and -15.3%, respectively), and residual increases in high-density lipoprotein cholesterol (HDL-C) were observed for the monotherapy groups receiving ANA 40 mg (18.6%), 150 mg (40.5%), and 300 mg (43.4%). The effects on apolipoprotein B and apolipoprotein A-I were consistent with the changes observed for LDL-C and HDL-C, respectively. Corresponding residual changes in LDL-C and HDL-C were also noted in the ATV coadministration groups at the similar doses of ANA compared with ATV 20 mg alone. Residual plasma drug levels accompanied by reductions in cholesteryl ester transfer protein activity were observed at week 16 and may account for the alterations in plasma lipids 8 weeks after cessation of ANA.

Factor XI Inhibition to Uncouple Thrombosis From Hemostasis: JACC Review Topic of the Week.

Hemostasis and thrombosis are believed to be so intricately linked that any strategies that reduce thrombosis will have an inevitable impact on hemostasis. Consequently, bleeding is viewed as an unavoidable side effect of anticoagulant therapy. Emerging evidence suggests that factor XI is important for thrombosis but has a minor role in hemostasis. This information raises the possibility that anticoagulants that target factor XI will be safer than currently available agents. The authors provide a visual representation of the coagulation pathways that distinguishes between the steps involved in thrombosis and hemostasis to explain why factor XI inhibitors may serve as hemostasis-sparing anticoagulants. A safer class of anticoagulants would provide opportunities for treatment of a wider range of patients, including those at high risk for bleeding. Ongoing clinical studies will determine the extent to which factor XI inhibitors attenuate thrombosis without disruption of hemostasis.

CRD-733, a Novel PDE9 (Phosphodiesterase 9) Inhibitor, Reverses Pressure Overload-Induced Heart Failure.

BACKGROUND: Augmentation of NP (natriuretic peptide) receptor and cyclic guanosine monophosphate (cGMP) signaling has emerged as a therapeutic strategy in heart failure (HF). cGMP-specific PDE9 (phosphodiesterase 9) inhibition increases cGMP signaling and attenuates stress-induced hypertrophic heart disease in preclinical studies. A novel cGMP-specific PDE9 inhibitor, CRD-733, is currently being advanced in human clinical studies. Here, we explore the effects of chronic PDE9 inhibition with CRD-733 in the mouse transverse aortic constriction pressure overload HF model. METHODS: Adult male C57BL/6J mice were subjected to transverse aortic constriction and developed significant left ventricular (LV) hypertrophy after 7 days (P<0.001). Mice then received daily treatment with CRD-733 (600 mg/kg per day; n=10) or vehicle (n=17), alongside sham-operated controls (n=10). RESULTS: CRD-733 treatment reversed existing LV hypertrophy compared with vehicle (P<0.001), significantly improved LV ejection fraction (P=0.009), and attenuated left atrial dilation (P<0.001), as assessed by serial echocardiography. CRD-733 prevented elevations in LV end diastolic pressures (P=0.037) compared with vehicle, while lung weights, a surrogate for pulmonary edema, were reduced to sham levels. Chronic CRD-733 treatment increased plasma cGMP levels compared with vehicle (P<0.001), alongside increased phosphorylation of Ser273 of cardiac myosin binding protein-C, a cGMP-dependent protein kinase I phosphorylation site. CONCLUSIONS: The PDE9 inhibitor, CRD-733, improves key hallmarks of HF including LV hypertrophy, LV dysfunction, left atrial dilation, and pulmonary edema after pressure overload in the mouse transverse aortic constriction HF model. Additionally, elevated plasma cGMP may be used as a biomarker of target engagement. These findings support future investigation into the therapeutic potential of CRD-733 in human HF.

Remote Cardiac Safety Monitoring through the Lens of the FDA Biomarker Qualification Evidentiary Criteria Framework: A Case Study Analysis.

Clinical safety findings remain one of the reasons for attrition of drug candidates during clinical development. Cardiovascular liabilities are not consistently detected in early-stage clinical trials and often become apparent when drugs are administered chronically for extended periods of time. Vital sign data collection outside of the clinic offers an opportunity for deeper physiological characterization of drug candidates and earlier safety signal detection. A working group representing expertise from biopharmaceutical and technology sectors, US Food and Drug Administration (FDA) public-private partnerships, academia, and regulators discussed and presented a remote cardiac monitoring case study at the FNIH Biomarkers Consortium Remote Digital Monitoring for Medical Product Development workshop to examine applicability of the biomarker qualification evidentiary framework by the FDA. This use case examined the components of the framework, including the statement of need, the context of use, the state of the evidence, and the benefit/risk profile. Examination of results from 2 clinical trials deploying 510(k)-cleared devices for remote cardiac data collection demonstrated the need for analytical and clinical validity irrespectively of the regulatory status of a device of interest, emphasizing the importance of data collection method assessment in the context of intended use. Additionally, collection of large amounts of ambulatory data also highlighted the need for new statistical methods and contextual information to enable data interpretation. A wider adoption of this approach for drug development purposes will require collaborations across industry, academia, and regulatory agencies to establish methodologies and supportive data sets to enable data interpretation and decision-making.

The Cardiac Safety Research Consortium electrocardiogram warehouse: thorough QT database specifications and principles of use for algorithm development and testing.

This document examines the formation, structure, and principles guiding the use of electrocardiogram (ECG) data sets obtained during thorough QT studies that have been derived from the ECG Warehouse of the Cardiac Safety Research Consortium (CSRC). These principles are designed to preserve the fairness and public interest of access to these data, commensurate with the mission of the CSRC. The data sets comprise anonymized XML formatted digitized ECGs and descriptive variables from placebo and positive control arms of individual studies previously submitted on a proprietary basis to the US Food and Drug Administration by pharmaceutical sponsors. Sponsors permit the release of these studies into the public domain through the CSRC on behalf of the Food and Drug Administration's Critical Path Initiative and public health interest. For algorithm research protocols submitted to and approved by CSRC, unblinded "training" ECG data sets are provided for algorithm development and for initial evaluation, whereas separate blinded "testing" data sets are used for formal algorithm evaluation in cooperation with the CSRC according to methods detailed in this document.

Design and rationale of the PROTECT study: a placebo-controlled randomized study of the selective A1 adenosine receptor antagonist rolofylline for patients hospitalized with acute decompensated heart failure and volume overload to assess treatment effect on congestion and renal function.

BACKGROUND: Current treatment for acute decompensated heart failure (ADHF) is associated with incomplete resolution of symptoms and signs, recurrent symptoms of heart failure in-hospital and after discharge and high mortality. Studies have consistently demonstrated an association between worsening renal function in ADHF and adverse outcomes. Adenosine A(1) receptor antagonists, such as rolofylline, appear in preliminary studies to produce potentially beneficial effects on natriuresis, diuresis, renal blood flow, and glomerular filtration rate. In a previous dose-finding study, rolofylline 30 mg intravenously daily for 3 days was associated with symptom improvement, less worsening of renal function, and trends toward lower 60-day rates of death or readmission for cardiovascular or renal causes. METHODS AND RESULTS: This manuscript describes the rationale underlying the design of the phase 3 PROTECT (Placebo-controlled Randomized study of the selective A(1) adenosine receptor antagonist rolofylline for patients hospitalized with acute heart failure and volume Overload to assess Treatment Effect on Congestion and renal funcTion) trial. CONCLUSION: Rolofylline 30 mg or matching placebo was given intravenously as a 4-hour continuous infusion on 3 consecutive days and the hospital course was assessed by measurements dyspnea, clinical status, renal function, and subsequent morbidity and mortality in a large population of patients with ADHF with renal impairment.

Physician-determined worsening heart failure: a novel definition for early worsening heart failure in patients hospitalized for acute heart failure--association with signs and symptoms, hospitalization duration, and 60-day outcomes.

OBJECTIVES: To evaluate physician-determined worsening heart failure (PD-WHF) in patients admitted with acute heart failure (AHF). METHODS: The PROTECT pilot study evaluated rolofylline, an adenosine A(1) receptor antagonist, versus placebo in patients with AHF and renal impairment. Signs and symptoms of heart failure (HF) and diuretic administration were prospectively recorded daily for 7 days and patients were followed for 60 days. Patients were categorized into three groups: (A) PD-WHF, based on worsening symptoms and signs of HF and need for additional intravenous (IV) or mechanical therapy (n = 29); (B) increased IV diuretic therapy without PD-WHF (n = 61), and (C) neither PD-WHF nor increase in IV diuretic dose (n = 211). RESULTS: Patients in group A had slower resolution of dyspnea, longer mean (+/-SD) length of hospitalization (13.8 +/- 6.8 vs. 10.5 +/- 8.5 and 9.3 +/- 5.9 days in groups B and C, respectively; p < 0.05 for both), and higher 60-day death and cardiovascular or renal readmission rates [49.7 (95% confidence interval: 33.1-69.1) vs. 37.3 (26.4-50.9) vs. 19.5% (14.7-25.6) in groups B and C, respectively]. PD-WHF was a strong independent predictor of length of stay and 60-day death and cardiovascular or renal readmission. CONCLUSIONS: PD-WHF may be an indicator of short-term risk and treatment efficacy in AHF.

Efficacy and safety of the cholesteryl ester transfer protein inhibitor anacetrapib as monotherapy and coadministered with atorvastatin in dyslipidemic patients.

BACKGROUND: High-density lipoprotein cholesterol (HDL-C) levels are inversely associated with cardiovascular risk. Cholesteryl ester transfer protein inhibition is one strategy for increasing HDL-C. This study evaluated the lipid-altering efficacy and safety of the cholesteryl ester transfer protein inhibitor anacetrapib as monotherapy or coadministered with atorvastatin in patients with dyslipidemia. METHODS: A total of 589 patients with primary hypercholesterolemia or mixed hyperlipidemia (53.8% of the study population had low HDL-C) were randomized equally to one of 10 groups: 5 groups received background statin therapy of atorvastatin 20 mg and 5 did not, and each of these was randomized to placebo, anacetrapib 10, 40, 150, and 300 mg once daily for 8 weeks. An equal proportion of patients had triglycerides >150 mg/dL in each group. RESULTS: For placebo and anacetrapib monotherapy (10, 40, 150, and 300 mg), least squares mean percent changes from baseline to week 8 for low-density lipoprotein cholesterol (LDL-C) were 2%, -16%, -27%, -40%, and -39%, respectively, and for HDL-C were 4%, 44%, 86%, 139%, and 133%, respectively (P < .001 vs placebo for all doses). Coadministration of anacetrapib with atorvastatin produced significant incremental LDL-C reductions and similar HDL-C increases versus atorvastatin monotherapy. For both anacetrapib monotherapy and coadministration with atorvastatin, the LDL-C reductions were similar in patients with baseline triglyceride levels greater than and less than or equal to the median. Anacetrapib was well tolerated, and the incidence of adverse events was similar for placebo and all active treatment groups. There were no increases in systolic or diastolic blood pressure in any treatment arm. CONCLUSIONS: Anacetrapib, as monotherapy or coadministered with atorvastatin, produced significant reductions in LDL-C and increases in HDL-C; the net result of treatment with anacetrapib + atorvastatin was approximately 70% lowering of LDL-C and more than doubling of HDL-C. Anacetrapib was generally well tolerated with no discernable effect on blood pressure.

A thorough QTc study to assess the effect of sitagliptin, a DPP4 inhibitor, on ventricular repolarization in healthy subjects.

A randomized, double-blind, placebo-controlled, 4-period crossover study was performed with a single oral dose of sitagliptin (100 mg, 800 mg), moxifloxacin (400 mg), and placebo in order to provide a rigorous assessment of the effect of sitagliptin on ventricular repolarization based on the ICH E14 guidance. The clinical dose of sitagliptin 100 mg was not associated with an increase in QTc interval, corrected using the Fridericia correction (QTcf), at any time point. The supratherapeutic 800-mg dose of sitagliptin was generally well tolerated and was associated with minimal, clinically insignificant prolongation of the QTcf interval at concentrations approximately 11-fold higher than maximal concentrations following the 100-mg clinical dose. The PK/QTc model demonstrated a shallow relationship between the plasma concentration of sitagliptin and the placebo-subtracted QTcf change from baseline, with a 0.59-millisecond increase in QTc for every 1000-nM increment in sitagliptin plasma concentration. The sensitivity of the assay to detect modest increases in QTc interval was established with the active control moxifloxacin. In conclusion, at clinically relevant concentrations, sitagliptin is not associated with clinically meaningful QTcf prolongation.

Low-dose leptin reverses skeletal muscle, autonomic, and neuroendocrine adaptations to maintenance of reduced weight.

Maintenance of a reduced body weight is accompanied by decreased energy expenditure that is due largely to increased skeletal muscle work efficiency. In addition, decreased sympathetic nervous system tone and circulating concentrations of leptin, thyroxine, and triiodothyronine act coordinately to favor weight regain. These "weight-reduced" phenotypes are similar to those of leptin-deficient humans and rodents. We examined metabolic, autonomic, and neuroendocrine phenotypes in 10 inpatient subjects (5 males, 5 females [3 never-obese, 7 obese]) under 3 sets of experimental conditions: (a) maintaining usual weight by ingesting a liquid formula diet; (b) maintaining a 10% reduced weight by ingesting a liquid formula diet; and (c) receiving twice-daily subcutaneous doses of leptin sufficient to restore 8 am circulating leptin concentrations to pre-weight-loss levels and remaining on the same liquid formula diet required to maintain a 10% reduced weight. During leptin administration, energy expenditure, skeletal muscle work efficiency, sympathetic nervous system tone, and circulating concentrations of thyroxine and triiodothyronine returned to pre-weight-loss levels. These responses suggest that the weight-reduced state may be regarded as a condition of relative leptin insufficiency. Prevention of weight regain might be achievable by strategies relevant to reversing this leptin-insufficient state.

Effect of the cholesteryl ester transfer protein inhibitor, anacetrapib, on lipoproteins in patients with dyslipidaemia and on 24-h ambulatory blood pressure in healthy individuals: two double-blind, randomised placebo-controlled phase I studies.

BACKGROUND: The inhibition of cholesteryl ester transfer protein (CETP) is considered a potential new mechanism for treatment of dyslipidaemia. Anacetrapib (MK-0859) is a CETP inhibitor currently under development. We aimed to assess anacetrapib's effects as monotherapy on low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) and on 24-h ambulatory blood pressure. METHODS: We did two double-blind, randomised, placebo-controlled phase I studies. In the first study, 50 patients with dyslipidaemia (LDL-C 100-190 mg/dL; 40 active, 10 placebo) aged 18-75 years received anacetrapib doses of 0, 10, 40, 150, or 300 mg orally once a day with a meal for 28 days. Standard lipid and lipoprotein monitoring, safety monitoring, and anacetrapib concentrations for pharmacokinetics were done. In the second study, 22 healthy participants aged 45-75 years received either 150 mg of anacetrapib once a day or matching placebo with a meal for 10 days in each crossover period, in a randomised sequence, with at least a 14-day washout between the treatment periods. Continuous 24-h ambulatory blood pressure monitoring was done on day -1 and day 10 of each treatment period in this study. The primary or secondary endpoints of safety and tolerability were assessed in both studies by monitoring clinical adverse experiences, physical examinations, vital signs, 12-lead electrocardiogram, and laboratory safety. Analysis was per protocol. These trials are registered with ClinicalTrials.gov, number NCT00565292 and NCT00565006. FINDINGS: In the dyslipidaemia study, one patient withdrew consent and one was excluded from the data analysis for HDL-C and LDL-C because complete pre-dose measurements were not available. Anacetrapib produced dose-dependent lipid-altering effects with peak lipid-altering effects of 129% (mean 51.1 [SD 3.8]-114.9 [7.9] mg/dL) increase in HDL-C and a 38% (138.2 [11.4]-77.6 [7.9] mg/dL) decrease in LDL-C in patients with dyslipidaemia. In the 24-h ambulatory blood pressure study in healthy individuals, least squares difference between anacetrapib and placebo groups on day 10 were 0.60 (90% CI -1.54 to 2.74; p=0.634) mm Hg for systolic blood pressure and 0.47 (90% CI -0.90 to 1.84; p=0.561) mm Hg for diastolic blood pressure. INTERPRETATION: Anacetrapib seems to exhibit HDL-C increases greater than those seen with other investigational drugs in this class and LDL-C lowering effects similar to statins. Despite greater lipid-altering effects relative to other members of this class, anacetrapib seems not to increase blood pressure, suggesting that potent CETP inhibition by itself might not lead to increased blood pressure.

The PROTECT pilot study: a randomized, placebo-controlled, dose-finding study of the adenosine A1 receptor antagonist rolofylline in patients with acute heart failure and renal impairment.

BACKGROUND: Rolofylline, an adenosine A(1) receptor antagonist, facilitates diuresis and preserves renal function in patients with acute heart failure (AHF) with renal impairment. Although not powered around any specific hypothesis, this pilot study was designed to identify an efficacious dose while refining inclusion criteria and end points. METHODS: A total of 301 patients hospitalized for AHF with an estimated creatinine clearance of 20 to 80 mL/min and elevated natriuretic peptide levels were enrolled within 24 hours of presentation to placebo or rolofylline 10, 20, or 30 mg administered as 4-hour infusions for 3 days in addition to intravenously administered loop diuretics. Post hoc analyses for end points chosen for subsequent Phase III studies were performed. RESULTS: Compared with placebo, rolofylline produced trends toward greater proportions of patients with marked or moderately improved dyspnea and fewer patients with worsening heart failure or renal function. Serum creatinine increased in patients receiving placebo and remained stable or tended to decrease in those receiving rolofylline. On day 14 the absolute differences between placebo and rolofylline for change in creatinine increased with increasing rolofylline dose, reflecting the lesser increase in creatinine in rolofylline-treated patients (r = -0.12, P = .030). Treatment with 30 mg, the dose selected for the pivotal trials, was associated with a trend toward reduced 60-day mortality or readmission for cardiovascular or renal cause (hazard ratio, 0.55; 95% confidence interval, 0.28-1.04). CONCLUSION: These results demonstrate that adenosine A(1) receptor blockade with rolofylline can prevent renal impairment in patients with AHF and may positively affect acute symptoms and 60-day outcome. A 2000-patient trial of this agent is now under way.