Prevention of sudden cardiac death in the young: Developing a rational, reliable, and sustainable national health care resource. A report from the Cardiac Safety Research Consortium.

This White Paper, prepared by members of the Cardiac Safety Research Consortium, discusses important issues regarding sudden cardiac death in the young (SCDY), a problem that does not discriminate by gender, race, ethnicity, education, socioeconomic level, or athletic status. The occurrence of SCDY has devastating impact on families and communities. Sudden cardiac death in the young is a matter of national and international public health, and its prevention has generated deep interest from multiple stakeholders, including families who have lost children, advocacy groups, academicians, regulators, and the medical industry. To promote scientific and clinical discussion of SCDY prevention and to germinate future initiatives to move this field forward, a Cardiac Safety Research Consortium-sponsored Think Tank was held on February 21, 2015 at the US Food and Drug Administration's White Oak facilities, Silver Spring, MD. The ultimate goal of the Think Tank was to spark initiatives that lead to the development of a rational, reliable, and sustainable national health care resource focused on SCDY prevention. This article provides a detailed summary of discussions at the Think Tank and descriptions of related multistakeholder initiatives now underway: it does not represent regulatory guidance.

Considerations for assessing the potential effects of antidiabetes drugs on cardiac ventricular repolarization: A report from the Cardiac Safety Research Consortium.

Thorough QT studies conducted according to the International Council on Harmonisation E14 guideline are required for new nonantiarrhythmic drugs to assess the potential to prolong ventricular repolarization. Special considerations may be needed for conducting such studies with antidiabetes drugs as changes in blood glucose and other physiologic parameters affected by antidiabetes drugs may prolong the QT interval and thus confound QT/corrected QT assessments. This review discusses potential mechanisms for QT/corrected QT interval prolongation with antidiabetes drugs and offers practical considerations for assessing antidiabetes drugs in thorough QT studies. This article represents collaborative discussions among key stakeholders from academia, industry, and regulatory agencies participating in the Cardiac Safety Research Consortium. It does not represent regulatory policy.

Cardiac imaging approaches to evaluate drug-induced myocardial dysfunction.

The ability to make informed benefit-risk assessments for potentially cardiotoxic new compounds is of considerable interest and importance at the public health, drug development, and individual patient levels. Cardiac imaging approaches in the evaluation of drug-induced myocardial dysfunction will likely play an increasing role. However, the optimal choice of myocardial imaging modality and the recommended frequency of monitoring are undefined. These decisions are complicated by the array of imaging techniques, which have varying sensitivities, specificities, availabilities, local expertise, safety, and costs, and by the variable time-course of tissue damage, functional myocardial depression, or recovery of function. This White Paper summarizes scientific discussions of members of the Cardiac Safety Research Consortium on the main factors to consider when selecting nonclinical and clinical cardiac function imaging techniques in drug development. We focus on 3 commonly used imaging modalities in the evaluation of cardiac function: echocardiography, magnetic resonance imaging, and radionuclide (nuclear) imaging and highlight areas for future research.

Resolution of ST-segment depression: A new prognostic marker in ST-segment elevation myocardial infarction.

AIMS: To evaluate the prognostic impact of ST depression resolution among patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary PCI in the Assessment of Pexelizumab in Acute Myocardial Infarction (APEX-AMI) trial. METHODS AND RESULTS: In this study, 4729 of 5745 patients had analysable ECGs demonstrating concomitant ST-segment depression. Resolution of summation operatorST elevation (STE-R) and summation operatorST depression (STD-R) on 30 min post-PCI ECGs was dichotomized into those with > or =50 vs. <50% ST-segment resolution. Overall, 1143 patients (24%) had STD-R<50%. These patients had higher risk characteristics including older age, female sex, diabetes, hypertension, prior CHF/MI, Killip class >I, triple vessel disease, and less frequent TIMI 3 flow in the culprit coronary vessel post-PCI. After multivariable adjustment and accounting for STE-R, STD-R<50% remained an independent predictor for 90 day death and the composite of death, cardiogenic shock, or CHF. When compared with patients with both STE-R and STD-R> or =50%, patients with both STE-R and STD-R<50% had the worst outcomes [hazard ratios (HR) 90 day death: 2.54; 95% confidence intervals (CI): 1.71-3.77; HR 90 day composite: 2.18; 95% CI: 1.63-2.91]. CONCLUSION: When ST depression is present in STEMI patients undergoing primary PCI, STD-R<50% provides independent prognostic value that is incremental to STE-R.

ST-segment recovery and outcome after primary percutaneous coronary intervention for ST-elevation myocardial infarction: insights from the Assessment of Pexelizumab in Acute Myocardial Infarction (APEX-AMI) trial.

BACKGROUND: Primary percutaneous coronary angioplasty is an effective and widely adopted treatment for acute myocardial infarction. A simple method of determining prognosis after primary percutaneous coronary intervention (PCI) would facilitate appropriate care and expedite hospital discharge. Thus, we determined the prognostic importance of various measures of ST-segment-elevation recovery after primary PCI in a large, contemporary cohort of patients with ST-elevation myocardial infarction. METHODS AND RESULTS: We analyzed ECG data describing the magnitude and extent of ST-segment elevation and deviation before and early after (ie, 30 minutes) primary PCI in the study cohort of 4866 subjects with electrocardiographically high-risk ST-elevation myocardial infarction enrolled in the Assessment of PEXelizumab in Acute Myocardial Infarction (APEX-AMI) trial. Associations among 6 methods for calculating ST-segment recovery, biomarker estimates of infarct size (ie, peak creatine kinase, creatine kinase-MB, and troponin I and T), and prespecified clinical outcomes (ie, rates of 90-day death and 90-day death, heart failure, or shock) were examined. All ST-segment-recovery methods provided strong prognostic information regarding clinical outcomes. A simple ST-segment-recovery method of residual ST-segment elevation measurement in the most affected lead on the post-PCI ECG performed as well as complex methods that required comparison of pre- and post-PCI ECGs or calculation of summed ST-segment deviation in multiple leads (ie, worst-lead residual ST elevation: adjusted hazard ratio for 90-day death rate [reference <1 mm]: 1 to <2 mm, 1.23 [95% CI 0.74 to 2.03]; > or =2 mm, 2.22 [95% CI 1.35 to 3.65], corrected c-index=0.832; 90-day death/congestive heart failure/shock [reference <1 mm]: 1 to <2 mm, 1.55 [95% CI 1.06 to 2.26]; > or =2 mm, 2.33 [95% CI 1.59 to 3.41], corrected c-index=0.802). Biomarker estimates of infarct size declined in association with enhanced ST-segment recovery. CONCLUSIONS: An ECG performed early after primary PCI is a simple, widely available, inexpensive, and powerful prognostic tool applicable to patients with ST-elevation myocardial infarction.

Contribution of angiographic and electrocardiographic parameters of reperfusion to prediction of mortality and morbidity after acute ST-elevation myocardial infarction: Insights from the Assessment of Pexelizumab in Acute Myocardial Infarction trial.

BACKGROUND: Reperfusion with primary percutaneous intervention (PCI) in ST-segment elevation myocardial infarction leads to improved clinical outcomes. The contribution angiographic vs electrocardiographic reperfusion parameters confer on prognosis is unclear. METHODS: A prespecified subset of the APEX-AMI trial patients was analyzed by independent angiographic and electrocardiographic core laboratories (n = 1,018). Angiographic reperfusion after PCI and electrocardiogram 30 minutes post-PCI were assessed. RESULTS: Of the 941 patients in the angiographic substudy, 796 (85%) attained post-PCI Thrombolysis In Myocardial Infarction (TIMI) flow 3 and 852 (91%) had TIMI Myocardial Perfusion Grade (TMPG) 2/3. There were 664 (71%) patients with residual ST elevation (ST-E) <2 mm. Ninety-day mortality and death/CHF/shock were lower in patients with TIMI flow 3 vs <3 (1.9% vs 6.2%, P = .002; 5.8% vs 10.4%, P = .044) and those with TMPG 2/3 vs 0/1 (2.0% vs 7.9%, P = .001; 6.0% vs 11.9%, P = .028). Patients with residual ST-E <2 mm had similar rates of mortality as those with > or =2 mm (2.3% vs 3.3%, P = .374) but lower rates of death/CHF/shock (5.2% vs 9.6%, P = .013). After multivariable adjustment, only post-PCI TMPG 2/3 was significantly associated with survival (P = .001), whereas residual ST-E (P = .606) and post-PCI TIMI flow grade (P = .086) were not. Conversely, residual ST-E > or =2 mm (P = .012) rather than angiographic reperfusion was associated with the composite of death/CHF/shock events. CONCLUSION: Angiographic and electrocardiographic estimates of reperfusion with primary PCI in ST-segment elevation myocardial infarction provide different and complementary predictions of morbidity and mortality.

Pexelizumab for acute ST-elevation myocardial infarction in patients undergoing primary percutaneous coronary intervention: a randomized controlled trial.

CONTEXT: Reperfusion with percutaneous transluminal coronary intervention (PCI) is effective at improving outcomes in patients with acute ST-elevation myocardial infarction (STEMI). However, in patients without prompt reestablishment of brisk coronary flow and tissue perfusion, mortality remains high, providing an opportunity for novel treatments, including anti-inflammatory agents. OBJECTIVE: To evaluate the effectiveness of pexelizumab, a humanized monoclonal antibody that binds the C5 component of complement, as an adjunct to PCI in improving 30-day mortality from STEMI. DESIGN, SETTING, AND PATIENTS: This trial was a prospective, multicenter, double-blind, placebo-controlled, phase 3 study of the intravenous administration of pexelizumab in conjunction with primary PCI in STEMI with prespecified high-risk electrocardiographic findings. The trial was intended to enroll 8500 patients, but in conjunction with the US Food and Drug Administration enrollment was modified to 5745 patients presenting from 296 hospitals in 17 countries from July 13, 2004, to May 11, 2006. INTERVENTIONS: Two thousand eight hundred eighty-five patients were randomly assigned to receive placebo and 2860 to receive pexelizumab given as a 2-mg/kg intravenous bolus prior to PCI followed by 0.05-mg/kg per hour infusion over the subsequent 24 hours. Patients were randomized within 6 hours of symptom onset. MAIN OUTCOME MEASURES: The primary end point was all-cause mortality through day 30. Secondary end points were death through day 90 and the composite of death, cardiogenic shock, or congestive heart failure through days 30 and 90. RESULTS: No difference in mortality through day 30 was observed between the pexelizumab and placebo treatment groups, with 116 patients (4.06%) and 113 patients (3.92%) who died in the respective groups (hazard ratio [HR], 1.04; 95% confidence interval [CI], 0.80-1.35; log-rank P = .78). The composite end points of death, shock, or heart failure were also similar with 257 patients (8.99%) receiving pexelizumab and 265 patients (9.19%) receiving placebo at 30 days (HR, 0.98; 95% CI, 0.83-1.16; P = .81) and 293 patients (10.24%) receiving pexelizumab and 293 patients (10.16%) receiving placebo at 90 days (HR, 1.01; 95% CI, 0.86-1.19; P = .91). CONCLUSION: In this large clinical trial of patients treated with primary PCI for STEMI, mortality was low and unaffected by administration of pexelizumab. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00091637.

Concerning the mechanism of pexelizumab's benefit in acute myocardial infarction.

BACKGROUND: The COMplement inhibition in Myocardial infarction treated with Angioplasty (COMMA) trial previously demonstrated an unexpected dose-dependent reduction in 90-day mortality after bolus/infusion of pexelizumab despite no reduction in the primary end point of myocardial infarction (MI) size. We examined whether the mortality benefit was related to established modulators of clinical benefit such as baseline demographics, time to treatment from symptom onset, myocardial perfusion post-percutaneous coronary intervention (PCI), and extent of ST resolution. METHODS AND RESULTS: Eight hundred fourteen patients were randomized into 3 groups; (1) placebo, (2) pexelizumab bolus 2.0 mg/kg and placebo infusion for 20 hours, and (3) pexelizumab bolus 2.0 and 0.05 mg/kg per hour infusion for 20 hours commencing 4 hours after the bolus. Subjects presented with ST elevation MI within 6 hours of symptom onset and underwent PCI, creatine kinase (CK), and CK-MB measurements taken sequentially to define CK-MB area under the curve (AUC) and sequential ECG's defined ST resolution and QRS infarct size. Whereas mortality for both placebo and bolus pexelizumab groups rose during later time after presentation, it remained low and did not change appreciably during the 6-hour randomization window when patients received pexelizumab bolus infusion. Amplification of the mortality benefit was evident in patients with the highest quartile of hemodynamic compromise, that is, heart rate > or = 90 beat/min and systolic blood pressure < or = 118 mm Hg (3.2% vs 11.3% P = .004). A significant interaction between treatment assignment and hemodynamic status (P = .013) existed after adjusting for age, race, and MI location. Clinical benefit was not related to infarct size, extent of ST elevation, or evidence of angiographic or electrocardiographic reperfusion. CONCLUSIONS: These data raise the possibility that the clinical benefit of pexelizumab is mediated through novel pathways such as reduction in apoptosis or other mechanisms.

Effect of pexelizumab on mortality in patients with acute myocardial infarction or undergoing coronary artery bypass surgery: a systematic overview.

BACKGROUND: Recent trials evaluating the C5 complement inhibitor, pexelizumab, have shown that modulation of inflammation during ischemia/reperfusion in patients with acute myocardial infarction (MI) or undergoing coronary artery bypass graft (CABG) surgery may improve clinical outcomes. METHODS: We performed a systematic overview of individual patient data from all completed randomized controlled trials of pexelizumab to evaluate the effect on all-cause mortality at 30 and 180 days after treatment. We used a random effects model and included all 5916 patients randomized in 4 clinical trials. Patients received placebo, pexelizumab bolus only or pexelizumab bolus followed by a 24-hour infusion. RESULTS: A significant reduction in mortality at 30 days was observed in patients treated with bolus plus infusion (n = 2476) compared with placebo (n = 2492) (2.9% vs 4.2%; relative risk [RR], 0.70; 95% confidence interval [CI], 0.52-0.95; P = .02), with no interaction according to disease state of CABG or acute MI (P for interaction .33). A trend toward a reduction in mortality was observed in patients who received bolus plus infusion or bolus only (n = 3429) compared with placebo (n = 2476) (3.5% vs 4.2%; RR, 0.85; 95% CI, 0.66-1.0975; P = .215), but not in patients who received bolus only (n = 937) compared with placebo (n = 937) (5.2% vs 5.4%; RR, 0.96; 95% CI, 0.66-1.41; P = .918). The mortality benefit with bolus plus infusion compared with placebo persisted through 180 days (P = .05). CONCLUSIONS: Pexelizumab reduced 30-day mortality in this systematic evaluation. Bolus plus infusion dose is being studied in ongoing trials in acute MI and CABG populations.

Phase 1 study of cardiac safety of TAS-102 in patients with advanced solid tumors.

PURPOSE: TAS-102 is a novel oral agent combining the antineoplastic thymidine-based nucleoside analogue, trifluridine, and the thymidine phosphorylase inhibitor, tipiracil (molar ratio 1:0.5). TAS-102 has shown good activity in refractory metastatic colorectal cancer with acceptable safety. No QT prolongation was seen in clinical studies. This study aimed to investigate TAS-102 cardiac safety for regulatory requirements. METHODS: This was a phase 1, non-randomized study in adults with advanced solid tumors. Intensive QT assessments were conducted at baseline, placebo, and following single and multiple doses of TAS-102 during a 28-day cycle. RESULTS: Following single- and multiple-dose administration (N = 30), the upper bounds of the one-sided 95 % confidence intervals for the difference between TAS-102 and placebo in time-matched baseline-subtracted 12-lead Holter QT intervals did not exceed 20 ms at any prespecified time point. One patient had a change from baseline in QTcI interval ≥60 ms, and one patient had a QTcI interval >500 ms following multiple-dose TAS-102 administration. No patient had an uncorrected QT, QTcF, or QTcB interval >500 ms. Based on the exposure-response analysis between TAS-102 plasma concentrations and the placebo-adjusted QTc intervals, none of the upper bounds of the one-sided 95 % prediction intervals exceeded 20 ms. There were no significant morphological changes for T or U waves. No cardiovascular AEs were reported in cycle 1. Across all cycles, no patient experienced an AE of ventricular tachycardia, ventricular fibrillation, syncope, or seizure. CONCLUSIONS: There was no clinically relevant relationship between TAS-102 plasma concentrations and QTc interval; TAS-102 had no clinically relevant effects on cardiac repolarization. CLINICAL TRIALS: ClinicalTrials.gov study number: NCT01867879.

Pexelizumab, an anti-C5 complement antibody, as adjunctive therapy to primary percutaneous coronary intervention in acute myocardial infarction: the COMplement inhibition in Myocardial infarction treated with Angioplasty (COMMA) trial.

BACKGROUND: Complement, activated during myocardial ischemia and reperfusion, causes myocardial damage through multiple processes. The COMplement inhibition in Myocardial infarction treated with Angioplasty (COMMA) trial was performed to determine the effect of pexelizumab, a C5 complement inhibitor, on infarct size in patients with ST-segment-elevation myocardial infarction (MI) undergoing primary percutaneous coronary intervention. METHODS AND RESULTS: In COMMA, 960 patients with MI (20% isolated inferior MI) were randomized to placebo, pexelizumab 2.0-mg/kg bolus, or pexelizumab 2.0-mg/kg bolus and 0.05-mg/kg per h infusion for 20 hours. Infarct size by creatine kinase-MB area under the curve, the primary outcome, did not differ significantly between groups (placebo median, 4393; bolus pexelizumab, 4526; bolus plus infusion pexelizumab, 4713 [ng/mL] x h; P=0.89 for bolus versus placebo; P=0.76 for bolus plus infusion versus placebo), nor did the composite of 90-day death, new or worsening heart failure, shock, or stroke (placebo, 11.1%; bolus, 10.7%; bolus plus infusion, 8.5%). The ninety-day mortality rate was significantly lower with pexelizumab bolus plus infusion (1.8% versus 5.9% with placebo; nominal P=0.014); the bolus-only group had an intermediate mortality rate (4.2%). CONCLUSIONS: In patients with ST-elevation MI undergoing percutaneous coronary intervention, pexelizumab had no measurable effect on infarct size. However, the significant reduction in mortality suggests that pexelizumab may benefit patients through alternative novel mechanisms and provides impetus for additional investigation.

Effect of pexelizumab, an anti-C5 complement antibody, as adjunctive therapy to fibrinolysis in acute myocardial infarction: the COMPlement inhibition in myocardial infarction treated with thromboLYtics (COMPLY) trial.

BACKGROUND: Complement activation mediates myocardial damage that occurs during ischemia and reperfusion through multiple pathways. We performed 2 separate, parallel, double-blind, placebo-controlled trials to determine the effects of pexelizumab (a novel C5 complement monoclonal antibody fragment) on infarct size in patients receiving reperfusion therapy: COMPlement inhibition in myocardial infarction treated with thromboLYtics (COMPLY) and COMplement inhibition in Myocardial infarction treated with Angioplasty (COMMA). The COMPLY trial is reported here. METHODS AND RESULTS: Overall, 943 patients with acute ST-segment elevation myocardial infarction (MI) (20% with isolated inferior MI) receiving fibrinolysis were randomly assigned <6 hours after symptom onset to placebo, pexelizumab 2.0-mg/kg bolus, or pexelizumab 2.0-mg/kg bolus plus 0.05 mg/kg per h for 20 hours. Infarct size determined by creatine kinase-MB area under the curve was the primary analysis, which included patients who received at least some study drug and fibrinolysis (n=920). The median infarct size did not differ by treatment (placebo, 5230; bolus, 4952; bolus plus infusion, 5557 [ng/mL] x h; bolus versus placebo, P=0.85; bolus plus infusion versus placebo, P=0.81), nor did the 90-day composite incidence of death, new or worsening congestive heart failure, shock, or stroke (placebo, 18.6%; bolus, 18.4%; bolus plus infusion, 19.7%). Pexelizumab inhibited complement for 4 hours with bolus-only dosing and for 20 to 24 hours with bolus-plus-infusion dosing, with no increase in infections. CONCLUSIONS: When used adjunctively with fibrinolysis, pexelizumab blocked complement activity but reduced neither infarct size by creatine kinase-MB assessment nor adverse clinical outcomes.

Prognostic usefulness of white blood cell count and temperature in acute myocardial infarction (from the CARDINAL Trial).

White blood cell (WBC) count and temperature are 2 global measures of inflammation that are systematically gathered and easily identifiable in a clinical setting, unlike many other markers of inflammation being investigated in patients with coronary artery disease. The prognostic usefulness of the WBC count and temperature were evaluated in a large acute myocardial infarction trial, the Complement And ReDuction of INfarct size after Angioplasty or Lytics program. Baseline and serial measurements of WBC counts and temperature were correlated with infarct size and clinical outcome.

Increased creatine kinase MB level predicts postoperative mortality after cardiac surgery independent of new Q waves.

BACKGROUND: Recent consensus statements recommend cardiac enzyme release as the essential criterion for diagnosing myocardial infarction. However, the outcome implications of cardiac enzyme release in patients undergoing coronary artery bypass grafting are controversial. METHODS: Eight hundred patients were followed for 30 days after elective on-pump coronary artery bypass grafting in a multicenter, prospective, randomized trial of the anti-C5 complement antibody pexelizumab. Data from centralized electrocardiography and creatine kinase MB analyses were examined for any association with death or severe left ventricular dysfunction. RESULTS: More than half of the 800 patients had peak creatine kinase MB levels of more than 5 times the upper limit of 5 ng/mL set by the core laboratory. The median peak value was 29 ng/mL. The incidence of the combined outcome (death or severe left ventricular dysfunction) was 1.7% if the peak creatine kinase MB level was less than 25 ng/mL and 18.0% if 100 ng/mL or greater (P < .01). Similarly, the incidence of new Q-wave myocardial infarction was 3.9% if the peak creatine kinase MB level was less than 25 ng/mL and 30.6% if 100 ng/mL or greater (P < .01). In a multivariate analysis that included preoperative and intraoperative factors, as well as peak enzyme release and Q-wave myocardial infarction, the strongest predictor of the combined outcome was a peak creatine kinase MB level of 100 ng/mL or greater. New Q-wave myocardial infarction did not significantly predict the combined outcome. CONCLUSIONS: Increased postoperative peak creatine kinase MB level, especially when 20 times or more of the upper limit of normal, indicates increased risk of severe postoperative left ventricular dysfunction and mortality within 30 days of coronary artery bypass grafting. High peak enzyme level is a stronger predictor of adverse outcomes than is postoperative Q-wave myocardial infarction in this population.

Cardiac Safety Research Consortium (CSRC): Cardiovascular Safety and Adverse Event Case Report Forms.

Detection of off-target cardiovascular (CV) effects remains a significant challenge to drug development. Documentation of CV events in non-CV trials is often inadequate to interpret imbalances between treatment arms, which may lead to concerns about potential CV safety "signals." The Cardiac Safety Research Consortium (CSRC) public-private partnership has developed CV case report forms (CRFs) for adverse CV events, including death. These CRFs are intended to encourage collection, as near to the occurrence of an event as possible, of the minimum information necessary to assess, or possibly adjudicate, the event. A broad range of stakeholders (representing industry, academia, and regulatory authorities) developed these forms with the goal of balancing the collection of key information with the resources likely to be available. Use of these forms is optional, and sponsors may modify them. These forms have not undergone any type of "validation" process. The CSRC will continue to sponsor a working group to invite public comment and feedback on these forms.

Clinical Development Approaches and Statistical Methodologies to Prospectively Assess the Cardiovascular Risk of New Antidiabetic Therapies for Type 2 Diabetes.

In December 2008, the US Food and Drug Administration (FDA) issued a guidance for industry requiring sponsors to demonstrate that a new antidiabetic therapy being developed to treat type 2 diabetes does not increase cardiovascular (CV) risk to an unacceptable extent. CV events reported during phase 2 and phase 3 trials should be prospectively and independently adjudicated. Before submission of a new drug application or biologics license application, sponsors should compare the incidence of major CV events occurring with the investigational agent versus the control group to show that the upper bound of the 2-sided 95% confidence interval (CI) for the estimated risk ratio is less than 1.8. If the CI includes 1.3, a postmarketing trial will be necessary to definitively show that the upper bound of the 95% CI for the estimated risk ratio is then less than 1.3. In 2012, the European Medicines Agency (EMA) issued an updated guideline on the clinical investigation of medicinal products in the treatment or prevention of diabetes mellitus that detailed its CV safety assessment requirements. Although similar to the FDA guidance, the EMA guideline does not prospectively define any pre- or postapproval risk margins. This expert perspective, prepared by members of the Cardiac Safety Research Consortium, discusses clinical development strategies, operational issues, and statistical methodological issues to satisfy the FDA's CV safety requirements, and, where appropriate, the EMA guideline. Actual case examples, where applicable, are presented.

Impact of pexelizumab, an anti-C5 complement antibody, on total mortality and adverse cardiovascular outcomes in cardiac surgical patients undergoing cardiopulmonary bypass.

BACKGROUND: During cardiac surgery requiring cardiopulmonary bypass, pro-inflammatory complement pathways are activated by exposure of blood to bio-incompatible surfaces of the extracorporeal circuit and reperfusion of ischemic organs. Complement activation promotes the generation of additional inflammatory mediators thereby exacerbating tissue injury. We examined the safety and efficacy of a C5 complement inhibitor for attenuating inflammation-mediated cardiovascular dysfunction in cardiac surgical patients undergoing cardiopulmonary bypass. METHODS: Pexelizumab (Alexion Pharmaceuticals, Inc, Cheshire, CT), a recombinant, single-chain, anti-C5 monoclonal antibody, was evaluated in a randomized, double-blinded, placebo-controlled, multicenter trial that involved 914 patients undergoing coronary artery bypass grafting with or without valve surgery requiring cardiopulmonary bypass. RESULTS: Pexelizumab was administered intravenously as a bolus (2.0 mg/kg) or bolus plus infusion (2.0 mg/kg plus 0.05 mg/kg/h for 24 hours), and inhibited complement activation. There were no statistically significant differences between placebo-treated and pexelizumab-treated patients in the primary endpoint (composite of death, or new Q-wave, or non-Q-wave [myocardial-specific isoform of creatine kinase > 60 ng/mL] myocardial infarction, or left ventricular dysfunction, or new central nervous system deficit). However, post hoc analysis revealed a reduction in the composite of death or myocardial infarction (myocardial-specific isoform of creatine kinase >/= 100 ng/mL) for the isolated coronary artery bypass grafting, bolus plus infusion subgroup on POD 4 (p = 0.007) and on POD 30 (p = 0.004). CONCLUSIONS: Pexelizumab had no statistically significant effect on the primary endpoint. However, the reduction in death or myocardial infarction (myocardial-specific isoform of creatine kinase >/= 100 ng/mL) as revealed in the post hoc analysis in the isolated coronary artery bypass grafting bolus plus infusion subpopulation, suggests that further investigation of anti-C5 therapy for ameliorating complement-mediated inflammation and myocardial injury is warranted.

Terminal complement blockade with pexelizumab during coronary artery bypass graft surgery requiring cardiopulmonary bypass: a randomized trial.

CONTEXT: Inflammation and ischemia-reperfusion injury during coronary artery bypass graft (CABG) surgery requiring cardiopulmonary bypass are associated with postoperative myocardial infarction (MI) and mortality. OBJECTIVE: To determine the efficacy and safety of pexelizumab, a C5 complement inhibitor, in reducing perioperative MI and mortality in CABG surgery. DESIGN, SETTING, AND PARTICIPANTS: A randomized, double-blind, placebo-controlled trial, including 3099 patients (> or = 18 years) undergoing CABG surgery with or without valve surgery at 205 hospitals in North America and Western Europe from January 2002 to February 2003. INTERVENTIONS: Patients were randomly assigned to receive intravenous pexelizumab (2.0 mg/kg bolus plus 0.05 mg/kg per hour for 24 hours; n = 1553) or placebo (n = 1546) 10 minutes before undergoing the procedure. MAIN OUTCOME MEASURES: The primary composite end point was the incidence of death or MI within 30 days of randomization in those undergoing CABG surgery only (n = 2746). Secondary analyses included the intent-to-treat analyses of death or MI composite at days 4 and 30 in all 3099 study patients. RESULTS: After 30 days, 134 (9.8%) of 1373 of patients receiving pexelizumab vs 161 (11.8%) of 1359 of patients receiving placebo (relative risk, 0.82; 95% confidence interval, 0.66-1.02; P =.07) died or experienced MI in the CABG surgery only population. In the intent-to-treat analyses, 178 (11.5%) of 1547 patients receiving pexelizumab vs 215 (14.0%) of 1535 receiving placebo died or experienced MI (relative risk, 0.82; 95% confidence interval, 0.68-0.99; P =.03). The trial was not powered to detect a reduction in mortality alone. CONCLUSIONS: Compared with placebo, pexelizumab was not associated with a significant reduction in the risk of the composite end point of death or MI in 2746 patients who had undergone CABG surgery only but was associated with a statistically significant risk reduction 30 days after the procedure among all 3099 patients undergoing CABG with or without valve surgery.

Prediction of enzymatic infarct size in ST-segment elevation myocardial infarction.

OBJECTIVES: Predictors of adverse outcomes following myocardial infarction (MI) are well established; however, little is known about what predicts enzymatically estimated infarct size in patients with acute ST-elevation MI. The Complement And Reduction of INfarct size after Angioplasty or Lytics trials of pexelizumab used creatine kinase (CK)-MB area under the curve to determine infarct size in patients treated with primary percutaneous coronary intervention (PCI) or fibrinolysis. METHODS: Prediction of infarct size was carried out by measuring CK-MB area under the curve in patients with ST-segment elevation MI treated with reperfusion therapy from January 2000 to April 2002. Infarct size was calculated in 1622 patients (PCI=817; fibrinolysis=805). Logistic regression was used to examine the relationship between baseline demographics, total ST-segment elevation, index angiographic findings (PCI group), and binary outcome of CK-MB area under the curve greater than 3000 ng/ml. RESULTS: Large infarcts occurred in 63% (515) of the PCI group and 69% (554) of the fibrinolysis group. Independent predictors of large infarcts differed depending on mode of reperfusion. In PCI, male sex, no prior coronary revascularization and diabetes, decreased systolic blood pressure, sum of ST-segment elevation, total (angiographic) occlusion, and nonright coronary artery culprit artery were independent predictors of larger infarcts (C index=0.73). In fibrinolysis, younger age, decreased heart rate, white race, no history of arrhythmia, increased time to fibrinolytic therapy in patients treated up to 2 h after symptom onset, and sum of ST-segment elevation were independently associated with a larger infarct size (C index=0.68). CONCLUSION: Clinical and patient data can be used to predict larger infarcts on the basis of CK-MB quantification. These models may be helpful in designing future trials and in guiding the use of novel pharmacotherapies aimed at limiting infarct size in clinical practice.

Effects of C5 complement inhibitor pexelizumab on outcome in high-risk coronary artery bypass grafting: combined results from the PRIMO-CABG I and II trials.

OBJECTIVE: The previous Pexelizumab for Reduction of Infarction and Mortality in Coronary Artery Bypass Graft Surgery I (PRIMO-CABG I) trial (n = 3099) indicated that C5 complement inhibition with pexelizumab might reduce myocardial infarction (MI) and postoperative mortality. PRIMO-CABG II was designed to investigate the safety and efficacy of terminal complement inhibition in reducing perioperative MI and mortality in patients undergoing CABG surgery who have 2 or more predefined preoperative risk factors. METHODS: PRIMO-CABG II, a randomized, double-blind, placebo-controlled trial, enrolled 4254 patients undergoing CABG with or without valve surgery at 249 hospitals in North America and Western Europe from June 2004 to July 2005. The patients were randomly assigned to receive intravenous pexelizumab or placebo. The primary composite endpoint was the incidence of death or MI within 30 days of randomization. RESULTS: The PRIMO-CABG II trial did not meet its prespecified primary endpoint of death or MI at 30 days, the secondary endpoints of death at 30 days, or the development of new or worsening congestive heart failure (relative risk 0.91, 0.82, and 1.01, respectively; P > .05). However, in a combined analysis of both pivotal trials, PRIMO-CABG I and II (n = 7353), death at 30 days was significantly reduced for the greatest risk subset (n = 2156, pexelizumab 5.7% vs placebo 8.1%, P = .024). Furthermore, this mortality reduction persisted throughout the 180-day follow-up period (pexelizumab 11.1% vs placebo 14.4%, P = .036). CONCLUSIONS: Pexelizumab was associated with a nonsignificant 6.7% reduction in the primary composite endpoint of death or MI at postoperative day 30 in CABG patients enrolled in the PRIMO-CABG II trial, despite the suggestion of a more favorable treatment effect in the previous PRIMO-CABG I trial. However, an exploratory analysis of the combined PRIMO I and II data set using an established predictive risk model showed a mortality benefit for high-risk surgical patients.