Perspectives on Some Controversies in Cardiovascular Disease Risk Assessment in the Pharmaceutical Development of Glucose-Lowering Medications.

The U.S. Food and Drug Administration (FDA) issued guidance on requirements to assess cardiovascular disease (CVD) risk with drugs being developed for approval for clinical use. The guidance was triggered by a meta-analysis published by Nissen and Wolski that suggested an increased risk for myocardial infarction with the use of rosiglitazone. This article discusses controversies around CVD trials in diabetes beginning with the University Group Diabetes Program. This is followed by a brief description of the FDA guidance for evaluating CVD risk with glucose-lowering medications. Limitations of meta-analyses of data from phase 2 and 3 (phase 2/3) trials to inform CVD risk are highlighted. These include the differences between patient characteristics in phase 2/3 trials and those in cardiovascular outcome trials (CVOTs) and the relatively short exposure time in phase 2/3 trials. The differences may partly explain the observed disparity between phase 2/3 meta-analyses and the results of completed CVOTs. Approaches to understanding CVD risk with a new medication should get to the answer about risk as efficiently as possible to minimize any potential harm to patients. In that context, we discuss options for clinical trial design and an alternative approach for statistical analyses.

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.

A clinical utility index for selecting an optimal insulin dosing algorithm for LY2605541 in patients with type 2 diabetes pretreated with basal insulin.

BACKGROUND: Because insulin dosing requires optimization of glycemic control, it is important to use a single metric of benefit and risk to determine best insulin dosing practices. We retrospectively applied a multiplicative clinical utility index (CUI) to a study of LY2605541 (Eli Lilly and Company, Indianapolis, IN), a novel, long-acting basal insulin. MATERIALS AND METHODS: A CUI was developed to transform the multidimensional problem of assessing benefit/risk of multiple dosing algorithms into a single decision-making metric to evaluate two LY2605541 dosing algorithms relative to the insulin glargine (GL) dosing algorithm. The CUI was applied to data in a 12-week, open-label, Phase 2 trial in patients with type 2 diabetes mellitus who were randomized to one of two dosing algorithms for LY2605541 (LY1 or LY2) or GL (algorithm similar to LY1). The CUI was created (via expert input) by weighing the relative benefit/risk of four components (glycosylated hemoglobin [HbA1c], percentage of patients with HbA1c ≤ 7%, hypoglycemia rate, and time to steady-state dose); individual utility values were multiplied to compute CUI values for LY1 and LY2 relative to GL, and bootstrap samples were used to determine variability. RESULTS: The mean CUI was 0.82 for LY1 and 1.35 for LY2. Based on 3,000 bootstrap samples, there was a 48% probability of LY2 performing better than LY1 and a 28% probability of LY1 performing better than LY2. CONCLUSIONS: CUI methodology, and in particular this CUI, is a useful tool for comparing dosing algorithms. Based on this CUI, LY2 is likely to be a better dosing algorithm than LY1.

Adaptive Design: Results of 2012 Survey on Perception and Use.

Adaptive designs are increasingly used in clinical trials. The Drug Information Association's Adaptive Design Scientific Working Group (ADSWG) works to foster collaboration among regulatory agencies, academia, and pharmaceutical and biotech companies to further the science of adaptive clinical development. The ADSWG Survey Subteam has collected data on the usage of adaptive designs in clinical research from multiple sources, including a recent ADSWG survey regarding the perception and usage of adaptive designs in academia and industry for studies between 2008 and 2011, as well as barriers to usage; a literature review examining publications of adaptive design methodology and usage between 2000 and 2011; and a trial registry review of adaptive design references from 1996 to 2011. The comprehensive results of the ADSWG 2012 survey are provided in this article with comparisons to our previous 2008 survey, the literature and registry reviews, and recent surveys carried out by the US Food and Drug Administration (FDA) and the European Medicines Agency. Results of the ADSWG 2012 survey illustrate that industry and academia are showing more enthusiasm for adaptive trials, accompanied by an increase in the number of trials using designs described as less well understood in the FDA draft guidance on adaptive designs, published in 2010. The increased use of these methods in exploratory trials is consistent with the FDA draft guidance. The survey also identified several examples of successful marketing applications supported by confirmatory trials utilizing adaptive designs that were considered, at least at the time of the draft guidance, as less well understood. While some of the technological barriers to adaptive design usage identified in the 2008 survey are now less common, there are several important persistent barriers to usage. Organizations can help overcome these barriers through education, preplanning, and early engagement in discussions with the regulators.

Operational challenges and solutions with implementation of an adaptive seamless phase 2/3 study.

A wide variety of operational issues were encountered with the planning and implementation of an adaptive, dose-finding, seamless phase 2/3 trial for a diabetes therapeutic. Compared with a conventional design, significant upfront planning was required, as well as earlier, more integrated cross-functional coordination. The existing infrastructure necessitated greater flexibility to meet the needs of the adaptive design. Rapid data acquisition, analysis, and reporting were essential to support the successful implementation of the adaptive algorithm. Drug supply for nine treatment arms had to be carefully managed across many sites worldwide. Details regarding these key operational challenges and others will be discussed along with resolutions taken to enable successful implementation of this adaptive, seamless trial.

Application of adaptive design methodology in development of a long-acting glucagon-like peptide-1 analog (dulaglutide): statistical design and simulations.

BACKGROUND: Dulaglutide (dula, LY2189265), a long-acting glucagon-like peptide-1 analog, is being developed to treat type 2 diabetes mellitus. METHODS: To foster the development of dula, we designed a two-stage adaptive, dose-finding, inferentially seamless phase 2/3 study. The Bayesian theoretical framework is used to adaptively randomize patients in stage 1 to 7 dula doses and, at the decision point, to either stop for futility or to select up to 2 dula doses for stage 2. After dose selection, patients continue to be randomized to the selected dula doses or comparator arms. Data from patients assigned the selected doses will be pooled across both stages and analyzed with an analysis of covariance model, using baseline hemoglobin A1c and country as covariates. The operating characteristics of the trial were assessed by extensive simulation studies. RESULTS: Simulations demonstrated that the adaptive design would identify the correct doses 88% of the time, compared to as low as 6% for a fixed-dose design (the latter value based on frequentist decision rules analogous to the Bayesian decision rules for adaptive design). CONCLUSIONS: This article discusses the decision rules used to select the dula dose(s); the mathematical details of the adaptive algorithm-including a description of the clinical utility index used to mathematically quantify the desirability of a dose based on safety and efficacy measurements; and a description of the simulation process and results that quantify the operating characteristics of the design.

An adaptive, dose-finding, seamless phase 2/3 study of a long-acting glucagon-like peptide-1 analog (dulaglutide): trial design and baseline characteristics.

Dulaglutide (dula, LY2189265) is a once-weekly glucagon-like peptide-1 analog in development for the treatment of type 2 diabetes mellitus. An adaptive, dose-finding, inferentially seamless phase 2/3 study was designed to support the development of this novel diabetes therapeutic. The study is divided into two stages based on two randomization schemes: a Bayesian adaptive scheme (stage 1) and a fixed scheme (stage 2). Stage 1 of the trial employs an adaptive, dose-finding design to lead to a dula dose-selection decision or early study termination due to futility. If dose selection occurs, the study proceeds to stage 2 to allow continued evaluation of the selected dula doses. At completion, the entire study will serve as a confirmatory phase 3 trial. The final study design is discussed, along with specifics pertaining to the actual execution of this study and selected baseline characteristics of the participants.

Viewpoints on the FDA draft adaptive designs guidance from the PhRMA working group.

The US Food and Drug Administration has recently released a draft guidance document on adaptive clinical trials. We comment on the document from the particular perspective of the authors as members of a PhRMA working group on this topic, which has interacted with FDA personnel on adaptive trial issue during recent years. We describe the activities and prior work of our working group, and use this as a basis to discuss the content of the guidance document as it relates to several issues of current relevance, such as data monitoring processes, adaptive dose finding, so-called seamless trial designs, and sample size reestimation.

Barriers and opportunities for implementation of adaptive designs in pharmaceutical product development.

BACKGROUND: This review discusses barriers to implementing adaptive designs in a pharmaceutical R&D environment and provides recommendations on how to overcome challenges. A summary of findings from a survey conducted through PhRMA's working group on adaptive designs is followed by a report based on our experience as statistical and clinical consultants to project teams charged with establishing the clinical development strategy for investigational compounds and interested in applying innovative approaches. FINDINGS AND RECOMMENDATIONS: Adaptive designs require additional work in that clinical trial simulations are needed to develop the design. Some project teams, due to time and resource constraints, are unable to invest the additional effort required to conduct necessary scenario analyses of options through simulation. We recommend formally integrating the planning time for scenario analyses and to incentivize optimal designs (e.g., designs offering the highest information value per resource unit invested). Regardless of the trial design ultimately chosen, quantitatively comparing alternative trial design options through simulation will enable earlier and better decision making in the context of the overall clinical development plan. Adhering to 'Good Adaptive Practices' will be key to achieving this goal. OUTLOOK: Implementing adaptive designs efficiently requires top-down and bottom- up support and the willingness to invest into integrated process and information technology infrastructures. Success is conditional on the willingness of the R&D environment to embrace the implementation of adaptive designs as a Change Management Initiative in the spirit of the Critical Path of the Food and Drug Administration.

Adaptive designs in clinical drug development: opportunities, challenges, and scope reflections following PhRMA's November 2006 workshop.

This paper provides reflections on the opportunities, scope and challenges of adaptive design as discussed at PhRMA's workshop held in November 2006. We also provide a status report of workstreams within PhRMA's working group on adaptive designs, which were triggered by the November workshop. Rather than providing a comprehensive review of the presentations given, we limit ourselves to a selection of key statements. The authors reflect the position of PhRMA's working group on adaptive designs.

Innovative approaches for designing and analyzing adaptive dose-ranging trials.

Inadequate selection of the dose to bring forward in confirmatory trials has been identified as one of the key drivers of the decreasing success rates observed in drug development programs across the pharmaceutical industry. In recognition of this problem, the Pharmaceutical Research and Manufacturers of America (PhRMA), formed a working group to evaluate and develop alternative approaches to dose finding, including adaptive dose-ranging designs. This paper summarizes the work of the group, including the results and conclusions of a comprehensive simulation study, and puts forward recommendations on how to improve dose ranging in clinical development, including, but not limited to, the use of adaptive dose-ranging methods.

Adaptive designs in clinical drug development--an Executive Summary of the PhRMA Working Group.

A PhRMA Working Group on adaptive clinical trial designs has been formed to investigate and facilitate opportunities for wider acceptance and usage of adaptive designs and related methodologies. A White Paper summarizing the findings of the group is in preparation; this article is an Executive Summary for that full White Paper, and summarizes the findings and recommendations of the group. Logistic, operational, procedural, and statistical challenges associated with adaptive designs are addressed. Three particular areas where it is felt that adaptive designs can be utilized beneficially are discussed: dose finding, seamless Phase II/III trials designs, and sample size reestimation.

Practice effects and the use of alternate forms in serial neuropsychological testing.

Accurate understanding of practice characteristics, performance stability, and error on neuropsychological tests is essential to both valid clinical assessment and maximization of signal detection for clinical trials of cognitive enhancing drugs. We examined practice effects in 28 healthy adults. As part of a larger study using donepezil and simulating a Phase I trial, participants were randomized into: placebo, no-treatment and donepezil. Donepezil results are presented elsewhere. Neuropsychological tests were administered in a fixed order for 6 weeks, with alternate forms available for most tests. Despite alternate forms, ANOVAs revealed significant improvements for the pooled control group (placebo and no-treatment) on all tests except Letter Number Sequencing and Trails B. Learning occurred principally in the first three to four sessions. PASAT and Stroop interference showed the greatest learning. Thus, serial assessment with alternate forms may attenuate retest effects on some tests, but continued learning occurs on novel tests or those in which an advantageous test-taking strategy can be identified. Alternate forms and baseline practice sessions may help control early, rapid improvements in clinical trials.

Neuropsychological test performance in healthy volunteers before and after donepezil administration.

Participants in early Phase I clinical trials for drugs designed to enhance cognition are typically healthy volunteers. If improvement can be detected with a battery of cognitive tests in healthy volunteers, such a battery could be a pharmacodynamic marker in the future development of the compound for treatment of cognitive disorders. In the present exploratory study, a battery of neuropsychological (NP) tests was used to determine if changes in cognition from a pharmacological intervention could be detected in healthy volunteers. A drug with known cognitive-enhancing effects in Alzheimer's disease, donepezil, was compared with placebo and no treatment arms. Carry-over effects of repeated test administration were also assessed. In this double-blind study, 27 healthy adults were randomized into one of three arms (eight donepezil, nine placebo and 10 no treatment) and completed 14 days of donepezil (5 mg q.h.s.) or placebo (q.h.s.). A battery of NP tests was administered on days 0, 7, 14 (randomization), 21, 28 (end of treatment) and 42 (washout). There were no differences in performance between the placebo and the no treatment arms. However, on day 21, subjects in the donepezil group performed slightly but significantly worse on some tests of speed, attention and memory (p < 0.05) compared to the pooled control group (placebo and no treatment arms). No improvement in performance was present while on donepezil at days 21 or 28. While the results are counter to expectations, some tests in the battery did detect a cognitive change (transient mild worsening during drug administration) in healthy volunteers.

LY354740, an mGlu2/3 receptor agonist as a novel approach to treat anxiety/stress.

Metabotropic glutamate (mGlu) receptors, which include mGlu1-8 receptors, are a heterogeneous family of G-protein coupled receptors (GPCRs) that function to modulate neuronal excitation and plasticity via pre-synaptic, post-synaptic and glial mechanisms. Agonists for group II mGlu receptors (mGlu2 and mGlu3), such as LY354740, have been shown to suppress enhanced glutamatergic excitations in brain synapses known to be involved in the expression of fear/anxiety in animals and humans. Systemic administration of LY354740 increases open-arm time in the elevated plus maze in mice under conditions of moderate to severe stress, blocks the expression but not development of fear-potentiated startle in rats, prevents lactate-induced panic-like responses in panic-prone rats, and attenuates certain physiological, behavioral, and neurochemical consequences of acute stress in rodents. In these preclinical models, LY354740 does not produce the side-effects (e.g. sedation) that are associated with other anxiolytic agents such as benzodiazepines. Early clinical results with LY354740 have demonstrated safety and efficacy in a human anxiety model (panic provocation induced by CO2 challenge). Collectively, these data indicate mGlu2/3 receptor agonists such as LY354740 represent a promising new approach for treatment of anxiety and stress-related disorders in humans.