Pathophysiological Sex Differences in Heart Failure Progression After Acute Coronary Syndrome: Insights From the EXAMINE Trial.

BACKGROUND: Therapies can reduce the risk of heart failure (HF) development and progression in type 2 diabetes; nevertheless, the risk of these outcomes is greater in females than in males. METHODS AND RESULTS: To investigate sex differences in HF development and progression, we compared baseline circulating proteins (Olink Cardiovascular II panel) in males and females with type 2 diabetes and recent acute coronary syndrome for the outcome of HF hospitalization. Data were from the placebo-controlled Examination of Cardiovascular Outcomes with Alogliptin vs Standard of Care (EXAMINE) trial. Pathophysiological sex-differences were interpreted with network and pathway over-representation analyses. The EXAMINE trial enrolled 5380 participants (32.1% females) with biomarker data available for 95.4% of individuals. Analyses revealed 43 biomarkers were differentially expressed in HF hospitalization, of which 18 were sex specific. Among these 43 biomarkers, interleukin-6 was identified as a central node for the pathogenesis of HF hospitalization in both females and in males. Additional pathway over-representation analyses demonstrated that biomarkers associated with inflammatory pathways related to endothelial dysfunction and cardiac fibrosis were more up-regulated in females than males with HF hospitalization. Differential expression of 3 biomarkers (pentraxin-related protein 3, hydroxyacid oxidase 1, and carbonic anhydrase 5A) was independently associated with an increased risk of HF hospitalization in females but not in males (interaction P < .05). CONCLUSIONS: In males and females with type 2 diabetes and acute coronary syndrome, interleukin-6 seems to be central in the pathogenesis of HF. Females exhibit higher levels of circulating proteins related to immunological pathways, reflecting sex-specific differences underlying HF development and progression.

External validation and extension of the TIMI risk score for heart failure in diabetes for patients with recent acute coronary syndrome: An analysis of the EXAMINE trial.

AIMS: The Thrombolysis in Myocardial Infarction Risk Score for Heart Failure (HF) in Diabetes (TRS-HFDM ) prognosticates HF hospitalization in people with type 2 diabetes (T2D). This study aimed to externally validate and extend its use for those with recent acute coronary syndrome (ACS). MATERIALS AND METHODS: The TRS-HFDM was externally validated in the Examination of Cardiovascular Outcomes with Alogliptin versus Standard of Care (EXAMINE) trial (n = 5380) and extended with natriuretic biomarkers. Missing data were multiply imputed. Initial TRS-HFDM variables were previous HF (2 points), atrial fibrillation (1 point), coronary artery disease (1 point), estimated glomerular filtration rate <60 ml/min/1.73 m2 (1 point), and urine albumin-to-creatinine ratio 30-300 mg/g (1 point) and >300 mg/g (2 points). RESULTS: In total, HF hospitalization occurred in 193 (3.6%) patients. Based on the TRS-HFDM , 25% of patients were classified as intermediate risk (1 point), 30% were classified as high risk (2 points), 19% were classified as very-high risk (3 points) and 26% were classified as severe risk (≥4 points). Before model extension, discrimination (C-index 0.76, 95%·CI 0.73-0.80) and calibration (calibration slope 0.82, 95%·CI 0.65-1.0; calibration-in-the-large -0.15, 95%·CI -0.37-0.64) were moderate-to-good in individuals with T2D and recent ACS. The extension of TRS-HFDM with the addition of N-terminal pro-B-type natriuretic peptide (NT-ProBNP) improved discrimination (C-index 0.82, 95%·CI 0.79-0.85) and calibration (calibration slope 0.84, 95%·CI 0.66-1.02; calibration-in-the-large -0.12, 95%·CI -0.33-0.081) for this higher-risk population. CONCLUSION: The TRS-HFDM with the extension of NT-ProBNP improves risk stratification and generalizes the use of the risk score for patients with T2D and ACS. Future validation studies in ACS populations may be warranted.

Optimal adaptive promising zone designs.

We develop optimal decision rules for sample size re-estimation in two-stage adaptive group sequential clinical trials. It is usual for the initial sample size specification of such trials to be adequate to detect a realistic treatment effect δa with good power, but not sufficient to detect the smallest clinically meaningful treatment effect δmin . Moreover it is difficult for the sponsors of such trials to make the up-front commitment needed to adequately power a study to detect δmin . It is easier to justify increasing the sample size if the interim data enter a so-called "promising zone" that ensures with high probability that the trial will succeed. We have considered promising zone designs that optimize unconditional power and promising zone designs that optimize conditional power and have discussed the tension that exists between these two objectives. Where there is reluctance to base the sample size re-estimation rule on the parameter δmin we propose a Bayesian option whereby a prior distribution is assigned to the unknown treatment effect δ , which is then integrated out of the objective function with respect to its posterior distribution at the interim analysis.

A simulation-based comparison of estimation methods for adaptive and classical group sequential clinical trials.

Statistical methods for controlling the type-I error of hypothesis tests in adaptive group sequential clinical trials are well established and well understood. However, methods for obtaining statistically valid point estimates and confidence intervals for adaptive designs are not as well established or as well understood. At the end of an adaptive trial, one may calculate the repeated confidence interval (RCI), which provides conservative coverage of δ , or the backward image confidence interval (BWCI), which provides exact coverage of δ and is an extension of the stagewise adjusted confidence interval (SWCI, used in classical group sequential designs). The BWCI can also provide a median unbiased estimate (MUE) of δ . There is a need to better understand the coverage and possible biases associated with these methods. We conducted a simulation study exploring parameter estimation following sample size reestimation based on testing methods with strong control of type-I error. Generally, the BWCI provided exact coverage, the naïve CI provided inconsistent coverage, and the RCI provided conservative coverage. Additionally, we note considerable asymmetry in the coverage from above/from below for the RCI, although we did not see any instance where the 95% RCI excluded the true parameter more than 2.5% on either side. At the end of an adaptive group sequential trial, we strongly recommend the use of the BWCI (and associated MUE), with the RCI computed during interim looks; the naïve CI should be avoided. These results and conclusions also hold true for classical group sequential designs.

Robust group sequential designs for trials with survival endpoints and delayed response.

Randomized clinical trials in oncology typically utilize time-to-event endpoints such as progression-free survival or overall survival as their primary efficacy endpoints, and the most commonly used statistical test to analyze these endpoints is the log-rank test. The power of the log-rank test depends on the behavior of the hazard ratio of the treatment arm to the control arm. Under the assumption of proportional hazards, the log-rank test is asymptotically fully efficient. However, this proportionality assumption does not hold true if there is a delayed treatment effect. Cancer immunology has evolved over time and several cancer vaccines are available in the market for treating existing cancers. This includes sipuleucel-T for metastatic hormone-refractory prostate cancer, nivolumab for metastatic melanoma, and pembrolizumab for advanced nonsmall-cell lung cancer. As cancer vaccines require some time to elicit an immune response, a delayed treatment effect is observed, resulting in a violation of the proportional hazards assumption. Thus, the traditional log-rank test may not be optimal for testing immuno-oncology drugs in randomized clinical trials. Moreover, the new immuno-oncology compounds have been shown to be very effective in prolonging overall survival. Therefore, it is desirable to implement a group sequential design with the possibility of early stopping for overwhelming efficacy. In this paper, we investigate the max-combo test, which utilizes the maximum of two weighted log-rank statistics, as a robust alternative to the log-rank test. The new test is implemented for two-stage designs with possible early stopping at the interim analysis time point. Two classes of weights are investigated for the max-combo test: the Fleming and Harrington (1981) Gρ,γ$G^{\rho , \gamma }$ weights and the Magirr and Burman (2019) modest (τ∗)$ (\tau ^{*})$  weights.

Body weight changes in patients with type 2 diabetes and a recent acute coronary syndrome: an analysis from the EXAMINE trial.

BACKGROUND: Patients with type 2 diabetes (T2D) may experience frequent body weight changes over time. The prognostic impact of these weight changes (gains or losses) requires further study. AIMS: To study the associations between changes in body weight (intentional or unintentional) with subsequent outcomes. METHODS: The EXAMINE trial included 5380 patients with T2D and a recent acute coronary syndrome, who were randomized to alogliptin or placebo. Time-updated Cox models and mixed effects models were used to test the associations between changes in body weight and subsequent outcomes over a median follow-up of 1.6 (1.0-2.1) years. RESULTS: During the post-randomization follow-up period, 1044 patients (19.4%) experienced a weight loss ≥ 5% of baseline weight, 2677 (49.8%) had a stable weight, and 1659 (30.8%) had a ≥ 5 % weight gain. Patients with weight loss were more frequently women and had more co-morbid conditions. In contrast, patients who gained ≥ 5% weight were more frequently men with less co-morbid conditions. A weight loss ≥ 5% was independently associated with a higher risk of subsequent adverse outcomes, including all-cause mortality: adjusted HR (95% CI) = 1.79 (1.33-2.42), P < 0.001. Similar associations were found for cardiovascular mortality, the composite of cardiovascular mortality or heart failure hospitalization, and the primary outcome. A weight gain ≥ 5% was independently associated with an increase in the risk of subsequent cardiovascular mortality or heart failure hospitalization only: adjusted HR (95% CI) = 1.34 (1.02-1.76), P = 0.033. CONCLUSIONS: In patients with T2D who had a recent ACS/MI, a ≥ 5% loss of body weight was associated with a higher risk of subsequent cardiovascular events and mortality.

Blood and Urine Biomarkers Predicting Worsening Kidney Function in Patients with Type 2 Diabetes Post-Acute Coronary Syndrome: An Analysis from the EXAMINE Trial.

INTRODUCTION: Worsening kidney function (WKF) is frequent among patients with type 2 diabetes (T2D) and a recent acute coronary syndrome (ACS) and is associated with a poor prognosis. An accurate prediction of WKF is clinically important. AIMS: Using data from the Cardiovascular Outcomes Study of Alogliptin in Patients with Type 2 Diabetes and Acute Coronary Syndrome trial including patients with T2D and a recent ACS, and a large biomarker panel incorporating proteins measured both in blood and urine, we aim to determine those with best performance for WKF prediction. METHODS: WKF was defined as a ≥40% estimated glomerular filtration rate (eGFR) drop from baseline, eGFR <15 mL/min, or dialysis. Mixed-effects and time-updated Cox models were used. RESULTS: 5,131 patients were included from whom 222 (4.3%) developed at least one WKF episode over a median follow-up of 18 months. Patients who developed WKF were more frequently women, had longer diabetes duration, a more frequent heart failure history, higher anemia prevalence, and impaired kidney function. In multivariable models including all variables (clinical and biomarkers) independently associated with WKF with a p value ≤0.0001, blood kidney injury molecule 1 (KIM-1) was (by far) the variable with strongest WKF association, followed by anemia. KIM-1 alone provided good discrimination for WKF prediction (area under the curve = 0.73). Patients in the high KIM-1-derived risk tertile had a 6.7-fold higher risk of any WKF than patients classified as low risk. In time-updated Cox models, the occurrence of WKF was independently associated with a higher risk of death: adjusted hazard ratio = 4.93 (3.06-7.96), p value <0.0001. CONCLUSION: Blood KIM-1 was the biomarker with the strongest association with WKF. The occurrence of WKF was independently associated with a higher risk of subsequent cardiovascular events and mortality.

Red cell distribution width in patients with diabetes and myocardial infarction: An analysis from the EXAMINE trial.

AIM: To determine the clinical correlates of increased red blood cell distribution width (RDW), its potential mechanistic association with multiple circulating biomarkers, and its prognostic value in patients with type 2 diabetes (T2D) who had a recent acute coronary syndrome. METHODS: We used time-updated Cox models applied to patients enrolled in the Examination of Cardiovascular Outcomes with Alogliptin versus Standard of Care (EXAMINE) trial. RESULTS: A total of 5380 patients were included, the median age was 61 years and 32% were women. Patients with higher RDW were older, more frequently women, with a longer diabetes duration and increased co-morbidities. An RDW of more than 16.1% (both baseline and time-updated) was independently associated with the study primary composite outcome of non-fatal myocardial infarction, non-fatal stroke or cardiovascular death (time-updated adjusted HR = 1.36, 95% CI = 1.16-1.61, p < .001), all-cause death (time-updated adjusted HR = 2.01, 95% CI = 1.60-2.53, p < .001), as well as mortality from non-cardiovascular causes (time-updated adjusted HR = 2.67, 95% CI = 1.72-4.15, p < .001). RDW had a weak-to-moderate correlation with haemoglobin and circulating markers that reflected inflammation, apoptosis, fibrosis and congestion. Alogliptin did not alter RDW values. CONCLUSIONS: RDW is a marker of disease severity associated with a multitude of poor outcomes, including both cardiovascular and non-cardiovascular death. RDW correlated modestly with inflammatory, pro-apoptotic, pro-fibrotic and congestion markers, and its levels were not affected by alogliptin during the course of the trial.

Alogliptin after acute coronary syndrome in patients with type 2 diabetes: a renal function stratified analysis of the EXAMINE trial.

BACKGROUND: The EXAMINE trial tested the efficacy and safety of alogliptin, an inhibitor of dipeptidyl peptidase 4, compared with placebo in 5380 patients with type 2 diabetes and a recent acute coronary syndrome. Because alogliptin is cleared by the kidney, patients were stratified according to screening renal function within two independently randomized strata: (1) estimated glomerular filtration rate (eGFR) ≥ 60 ml/min/1.73m2 and (2) eGFR < 60 ml/min/1.73m2. We aim to assess the efficacy and safety of alogliptin vs. placebo according to the renal function strata. METHODS: Cox-proportional hazard models with an interaction term by renal function strata were used. The primary endpoint was a composite of cardiovascular death, nonfatal myocardial infarction (MI), or nonfatal stroke. RESULTS: Patient characteristics were balanced within each renal function strata. In total, 3946 patients were randomized within the eGFR ≥ 60 stratum, and 1434 patients within the eGFR < 60 stratum. The effect of alogliptin was modified by the renal function strata. PRIMARY OUTCOME: eGFR ≥ 60 HR = 0.81, 95%CI, 0.65-0.99, and eGFR < 60 HR = 1.20, 95%CI, 0.95-1.53; interactionp = 0.014. Cardiovascular death: eGFR ≥ 60 HR = 0.61, 95%CI, 0.42-0.88, and eGFR < 60 HR = 1.16, 95%CI, 0.82-1.65; interactionp = 0.013. Non-fatal MI: eGFR ≥ 60 HR = 0.86, 95%CI, 0.66-1.13, and eGFR < 60 HR = 1.48, 95%CI, 1.07-2.06; interactionp = 0.013. CONCLUSIONS: Alogliptin may benefit patients with eGFR ≥ 60, but may be detrimental to patients with eGFR < 60 ml/min/1.73m2. These hypothesis-generating findings require further validation to assess the potential benefit and risk of alogliptin across the renal function spectrum among patients with type 2 diabetes and a recent acute coronary syndrome. TRIAL REGISTRATION: ClinicalTrials.gov, NCT00968708.

Timing of randomization after an acute coronary syndrome in patients with type 2 diabetes mellitus.

BACKGROUND: The timing of enrolment following an acute coronary syndrome (ACS) may influence cardiovascular (CV) outcomes and potentially treatment effect in clinical trials. Understanding the timing and type of clinical events after an ACS will allow for clinicians to better tailor evidence-based treatments to optimize therapeutic effect. Using a large contemporary trial in patients with type 2 diabetes mellitus (T2DM) post-ACS, we examined the impact of timing of enrolment on subsequent CV outcomes. METHODS: EXAMINE was a randomized trial of alogliptin versus placebo in 5,380 patients with T2DM and a recent ACS from October 2009 to March 2013. The primary outcome was a composite of CV death, nonfatal myocardial infarction (MI), or nonfatal stroke. The median follow-up was 18 months. In this post hoc analysis, we examined the occurrence of subsequent CV events by timing of enrollment divided by tertiles of time from ACS to randomization: 8-34, 35-56, and 57-141 days. RESULTS: Patients randomized early (compared to the latest times) had less comorbidities at baseline including a history of heart failure (HF; 24.7% vs 33.0%), prior coronary artery bypass graft (9.6% vs 15.9%), or atrial fibrillation (5.9% vs 9.4%). Despite the reduced comorbidity burden, the risk of the primary outcome was highest in patients randomized early compared to the latest time (adjusted hazard ratio 1.47; 95% CI 1.21-1.74). Similarly, patients randomized early had an increased risk of recurrent MI (adjusted hazard ratio 1.51; 95% CI 1.17-1.96) and HF hospitalization (1.49; 95% CI 1.05-2.10). CONCLUSIONS: In a contemporary cohort of T2DM with a recent ACS, the risk for recurrent CV events including MI and HF hospitalization is elevated early after an ACS. Given the emergence of antihyperglycemic therapies that reduce the risk of MI and HF among patients with T2DM at high CV risk, future studies evaluating the initiation of these therapies in the early period following an ACS are warranted given the large burden of potentially modifiable CV events.

Adaptive multiarm multistage clinical trials.

Two methods for designing adaptive multiarm multistage (MAMS) clinical trials, originating from conceptually different group sequential frameworks are presented, and their operating characteristics are compared. In both methods pairwise comparisons are made, stage-by-stage, between each treatment arm and a common control arm with the goal of identifying active treatments and dropping inactive ones. At any stage one may alter the future course of the trial through adaptive changes to the prespecified decision rules for treatment selection and sample size reestimation, and notwithstanding such changes, both methods guarantee strong control of the family-wise error rate. The stage-wise MAMS approach was historically the first to be developed and remains the standard method for designing inferentially seamless phase 2-3 clinical trials. In this approach, at each stage, the data from each treatment comparison are summarized by a single multiplicity adjusted P-value. These stage-wise P-values are combined by a prespecified combination function and the resultant test statistic is monitored with respect to the classical two-arm group sequential efficacy boundaries. The cumulative MAMS approach is a more recent development in which a separate test statistic is constructed for each treatment comparison from the cumulative data at each stage. These statistics are then monitored with respect to multiplicity adjusted group sequential efficacy boundaries. We compared the powers of the two methods for designs with two and three active treatment arms, under commonly utilized decision rules for treatment selection, sample size reestimation and early stopping. In our investigations, which were carried out over a reasonably exhaustive exploration of the parameter space, the cumulative MAMS designs were more powerful than the stage-wise MAMS designs, except for the homogeneous case of equal treatment effects, where a small power advantage was discernable for the stage-wise MAMS designs.

Reassessing the Role of Surrogate End Points in Drug Development for Heart Failure.

With few notable exceptions, drug development for heart failure (HF) has become progressively more challenging, and there remain no definitively proven therapies for patients with acute HF or HF with preserved ejection fraction. Inspection of temporal trends suggests an increasing rate of disagreement between early-phase and phase III trial end points. Preliminary results from phase II HF trials are frequently promising, but increasingly followed by disappointing phase III results. Given this potential disconnect, it is reasonable to carefully re-evaluate the purpose, design, and execution of phase II HF trials, with particular attention directed toward the surrogate end points commonly used by these studies. In this review, we offer a critical reappraisal of the role of phase II HF trials and surrogate end points, highlighting challenges in their use and interpretation, lessons learned from past experiences, and specific strengths and weaknesses of various surrogate outcomes. We conclude by proposing a series of approaches that should be considered for the goal of optimizing the efficiency of HF drug development. This review is based on discussions between scientists, clinical trialists, industry and government sponsors, and regulators that took place at the Cardiovascular Clinical Trialists Forum in Washington, DC, on December 2, 2016.

Optimal promising zone designs.

Clinical trials with adaptive sample size reassessment based on an unblinded analysis of interim results are perhaps the most popular class of adaptive designs (see Elsäßer et al., 2007). Such trials are typically designed by prespecifying a zone for the interim test statistic, termed the promising zone, along with a decision rule for increasing the sample size within that zone. Mehta and Pocock (2011) provided some examples of promising zone designs and discussed several procedures for controlling their type-1 error. They did not, however, address how to choose the promising zone or the corresponding sample size reassessment rule, and proposed instead that the operating characteristics of alternative promising zone designs could be compared by simulation. Jennison and Turnbull (2015) developed an approach based on maximizing expected utility whereby one could evaluate alternative promising zone designs relative to a gold-standard optimal design. In this paper, we show how, by eliciting a few preferences from the trial sponsor, one can construct promising zone designs that are both intuitive and achieve the Jennison and Turnbull (2015) gold-standard for optimality.

Serial Measurement of High-Sensitivity Troponin I and Cardiovascular Outcomes in Patients With Type 2 Diabetes Mellitus in the EXAMINE Trial (Examination of Cardiovascular Outcomes With Alogliptin Versus Standard of Care).

BACKGROUND: We aimed to describe the relationship between changes in high-sensitivity cardiac troponin I (hsTnI) and cardiovascular outcomes. METHODS: The EXAMINE trial (Examination of Cardiovascular Outcomes With Alogliptin Versus Standard of Care) was a phase IIIb clinical outcomes trial designed to evaluate the cardiovascular safety of alogliptin, a nonselective dipeptidyl peptidase 4 inhibitor. Patients with type 2 diabetes mellitus, glycohemoglobin between 6.5% and 11% (or between 7% and 11% if they were on insulin), and a recent acute coronary syndrome (between 15 and 90 days before randomization) were eligible for the trial. hsTnI was measured using the Abbott ARCHITECT assay at baseline and 6 months in patients randomized in the EXAMINE trial. This analysis was restricted to patients randomized ≥30 days after qualifying acute coronary syndrome to mitigate the potential for persistent hsTnI elevation after acute coronary syndrome (n=3808). The primary end point of the trial was cardiovascular death, myocardial infarction, or stroke. Cardiovascular death or heart failure was a prespecified, adjudicated secondary end point. RESULTS: At baseline, hsTnI was detectable (≥1.9 ng/L) in 93% of patients and >99th percentile upper reference limit in 16%. There was a strong relationship between increasing hsTnI, both at baseline and 6 months, and the incidence of cardiovascular events through 24 months (P<0.001 for each). Patients with undetectable hsTnI at baseline and 6 months were at the lowest risk of future cardiovascular events. Stable patients with hsTnI ≥99th percentile upper reference limit at 6 months were at increased risk of cardiovascular death, myocardial infarction, or stroke compared with patients with hsTnI <99 percentile upper reference limit irrespective of whether hsTnI was newly elevated (28.1% versus 8.8%; adjusted hazard ratio, 2.65; 95% confidence interval, 1.64-4.28; P<0.001) or persistently so (22.5% versus 8.8%; adjusted hazard ratio, 1.90; 95% confidence interval, 1.33-2.70; P<0.001). Alogliptin neither increased nor decreased the risk of cardiovascular events compared with placebo in patients with high baseline hsTnI (22.3% versus 23.0%; hazard ratio, 0.87; 95% confidence interval, 0.60-1.25; P=0.44). CONCLUSIONS: Serial assessment of hsTnI revealed a substantial proportion of patients with type 2 diabetes mellitus without clinically recognized events had dynamic or persistently elevated values and were at high risk of recurrent events. hsTnI may have a role in personalizing preventive strategies in patients with diabetes mellitus based on risk. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00968708.

A randomized, controlled trial of oral propranolol in infantile hemangioma.

BACKGROUND: Oral propranolol has been used to treat complicated infantile hemangiomas, although data from randomized, controlled trials to inform its use are limited. METHODS: We performed a multicenter, randomized, double-blind, adaptive, phase 2-3 trial assessing the efficacy and safety of a pediatric-specific oral propranolol solution in infants 1 to 5 months of age with proliferating infantile hemangioma requiring systemic therapy. Infants were randomly assigned to receive placebo or one of four propranolol regimens (1 or 3 mg of propranolol base per kilogram of body weight per day for 3 or 6 months). A preplanned interim analysis was conducted to identify the regimen to study for the final efficacy analysis. The primary end point was success (complete or nearly complete resolution of the target hemangioma) or failure of trial treatment at week 24, as assessed by independent, centralized, blinded evaluations of standardized photographs. RESULTS: Of 460 infants who underwent randomization, 456 received treatment. On the basis of an interim analysis of the first 188 patients who completed 24 weeks of trial treatment, the regimen of 3 mg of propranolol per kilogram per day for 6 months was selected for the final efficacy analysis. The frequency of successful treatment was higher with this regimen than with placebo (60% vs. 4%, P<0.001). A total of 88% of patients who received the selected propranolol regimen showed improvement by week 5, versus 5% of patients who received placebo. A total of 10% of patients in whom treatment with propranolol was successful required systemic retreatment during follow-up. Known adverse events associated with propranolol (hypoglycemia, hypotension, bradycardia, and bronchospasm) occurred infrequently, with no significant difference in frequency between the placebo group and the groups receiving propranolol. CONCLUSIONS: This trial showed that propranolol was effective at a dose of 3 mg per kilogram per day for 6 months in the treatment of infantile hemangioma. (Funded by Pierre Fabre Dermatologie; ClinicalTrials.gov number, NCT01056341.).

A gatekeeping procedure to test a primary and a secondary endpoint in a group sequential design with multiple interim looks.

Glimm et al. (2010) and Tamhane et al. (2010) studied the problem of testing a primary and a secondary endpoint, subject to a gatekeeping constraint, using a group sequential design (GSD) with K=2 looks. In this article, we greatly extend the previous results to multiple (K>2) looks. If the familywise error rate (FWER) is to be controlled at a preassigned α level then it is clear that the primary boundary must be of level α. We show under what conditions one α-level primary boundary is uniformly more powerful than another. Based on this result, we recommend the choice of the O'Brien and Fleming (1979) boundary over the Pocock (1977) boundary for the primary endpoint. For the secondary endpoint the choice of the boundary is more complicated since under certain conditions the secondary boundary can be refined to have a nominal level α'>α, while still controlling the FWER at level α, thus boosting the secondary power. We carry out secondary power comparisons via simulation between different choices of primary-secondary boundary combinations. The methodology is applied to the data from the RALES study (Pitt et al., 1999; Wittes et al., 2001). An R library package gsrsb to implement the proposed methodology is made available on CRAN.

High-sensitivity C-reactive protein, low-density lipoprotein cholesterol and cardiovascular outcomes in patients with type 2 diabetes in the EXAMINE (Examination of Cardiovascular Outcomes with Alogliptin versus Standard of Care) trial.

AIMS: We sought to assess the risk of major adverse cardiovascular events (MACE) by utilizing high-sensitivity C-reactive protein (hsCRP) level and low-density lipoprotein cholesterol (LDL-C) in patients with type 2 diabetes and recent acute coronary syndrome. MATERIALS AND METHODS: Study participants enrolled in the EXAMINE trial (Clinical trials registration number: NCT00968708) and were stratified by baseline hsCRP levels (<1, 1-3 and >3 mg/L). They were also sub-divided into 4 groups according to baseline hsCRP (≤3 or >3 mg/L) and achieved LDL-C (<70 or ≥70 mg/dL) levels. Among 5380 patients, the MACE rate, a composite of cardiovascular death, non-fatal acute myocardial infarction and non-fatal stroke, was evaluated during the 30 months of follow-up. RESULTS: Cumulative incidence of MACE was 11.5% (119 events), 14.6% (209 events) and 18.4% (287 events) in patients with hsCRP levels of <1, 1 to 3 and >3 mg/L, respectively (P < .001). In patients with hsCRP >3 mg/L, the adjusted hazard ratio (95% confidence interval) was 1.42 (1.13, 1.78; P = .002) for MACE compared with patients with hsCRP <1 mg/L. MACE cumulative incidences were 11.0% (128 events), 14.4% (100 events), 15.6% (194 events) and 21.3% (182 events) in patients with low LDL-C and low hsCRP, low LDL-C and high hsCRP, high LDL-C and low hsCRP, and high LDL-C and high hsCRP levels, respectively (P < .001). CONCLUSIONS: Levels of hsCRP were associated with recurrent cardiovascular events in patients with type 2 diabetes and recent acute coronary syndrome, and this association appears to be independent of and additive to the achieved LDL-C level.

Design and monitoring of multi-arm multi-stage clinical trials.

Two-arm group sequential designs have been widely used for over 40 years, especially for studies with mortality endpoints. The natural generalization of such designs to trials with multiple treatment arms and a common control (MAMS designs) has, however, been implemented rarely. While the statistical methodology for this extension is clear, the main limitation has been an efficient way to perform the computations. Past efforts were hampered by algorithms that were computationally explosive. With the increasing interest in adaptive designs, platform designs, and other innovative designs that involve multiple comparisons over multiple stages, the importance of MAMS designs is growing rapidly. This article provides break-through algorithms that can compute MAMS boundaries rapidly thereby making such designs practical. For designs with efficacy-only boundaries the computational effort increases linearly with number of arms and number of stages. For designs with both efficacy and futility boundaries the computational effort doubles with successive increases in number of stages.

Relationship of glycated haemoglobin and reported hypoglycaemia to cardiovascular outcomes in patients with type 2 diabetes and recent acute coronary syndrome events: The EXAMINE trial.

AIMS: To investigate relationships between glycated haemoglobin (HbA1c) and reported hypoglycaemia and risk of major adverse cardiovascular events (MACE). METHODS: The EXAMINE trial randomized 5380 patients with type 2 diabetes (T2DM) and a recent acute coronary syndrome (ACS) event, in 49 countries, to double-blind treatment with alogliptin or placebo in addition to standard of care. We used Cox proportional hazards models to analyse relationships among MACE, HbA1c levels and hypoglycaemic events. RESULTS: Patients randomized to alogliptin achieved lower HbA1c levels than the placebo group in all baseline HbA1c categories without differences in hypoglycaemia rates. No systematic change was found in MACE rates according to baseline HbA1c (Pinteraction = 0.971) or HbA1c category at 1 month. Patients in the combined treatment groups (n = 5380) who experienced serious hypoglycaemia (n = 34) had higher MACE rates than those who did not (35.3% vs 11.4%, adjusted hazard ratio [HR] 2.42, 95% confidence interval [CI] 1.27-4.60; P = .007), although the association was less strong when analysing only events after the hypoglycaemic event (adjusted HR 1.60, 95% CI 0.80, 3.20). CONCLUSIONS: There were no relationships between baseline HbA1c levels or HbA1c levels after 1 month of treatment and the risk of MACE. Alogliptin improved glycaemic control without increasing hypoglycaemia. Reported events of hypoglycaemia and serious hypoglycaemia were associated with MACE. These data underscore the safety of alogliptin in improving glycaemic control in T2DM post-ACS. Further study of hypoglycaemia as an independent risk factor for MACE in patients with T2DM and coronary disease is needed.

Heart failure and mortality outcomes in patients with type 2 diabetes taking alogliptin versus placebo in EXAMINE: a multicentre, randomised, double-blind trial.

BACKGROUND: The EXAMINE trial showed non-inferiority of the DPP-4 inhibitor alogliptin to placebo on major adverse cardiac event (MACE) rates in patients with type 2 diabetes and recent acute coronary syndromes. Concerns about excessive rates of in-hospital heart failure in another DPP-4 inhibitor trial have been reported. We therefore assessed hospital admission for heart failure in the EXAMINE trial. METHODS: Patients with type 2 diabetes and an acute coronary syndrome event in the previous 15-90 days were randomly assigned alogliptin or placebo plus standard treatment for diabetes and cardiovascular disease prevention. The prespecified exploratory extended MACE endpoint was all-cause mortality, non-fatal myocardial infarction, non-fatal stroke, urgent revascularisation due to unstable angina, and hospital admission for heart failure. The post-hoc analyses were of cardiovascular death and hospital admission for heart failure, assessed by history of heart failure and brain natriuretic peptide (BNP) concentration at baseline. We also assessed changes in N-terminal pro-BNP (NT-pro-BNP) from baseline to 6 months. This study is registered with ClinicalTrials.gov, number NCT00968708. FINDINGS: 5380 patients were assigned to alogliptin (n=2701) or placebo (n=2679) and followed up for a median of 533 days (IQR 280-751). The exploratory extended MACE endpoint was seen in 433 (16·0%) patients assigned to alogliptin and in 441 (16·5%) assigned to placebo (hazard ratio [HR] 0·98, 95% CI 0·86-1·12). Hospital admission for heart failure was the first event in 85 (3·1%) patients taking alogliptin compared with 79 (2·9%) taking placebo (HR 1·07, 95% CI 0·79-1·46). Alogliptin had no effect on composite events of cardiovascular death and hospital admission for heart failure in the post hoc analysis (HR 1·00, 95% CI 0·82-1·21) and results did not differ by baseline BNP concentration. NT-pro-BNP concentrations decreased significantly and similarly in the two groups. INTERPRETATION: In patients with type 2 diabetes and recent acute coronary syndromes, alogliptin did not increase the risk of heart failure outcomes. FUNDING: Takeda Development Center Americas.