Brenda Gaydos

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.

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.

Good Practices for Adaptive Clinical Trials in Pharmaceutical Product Development

This article is a summary of good adaptive practices for the planning and implementation of adaptive designs compiled from experiences gained in the pharmaceutical industry. The target audience is anyone involved in the planning and execution of clinical trials. The first step prior to planning an adaptive design is to assess the appropriateness of its use. Hence, strategic points to consider when assessing if an adaptive design is the right choice for a trial are discussed. In addition, strategic points for consideration at the design and implementation stage are included from operational, regulatory, clinical, and statistical perspectives. Good practices for trial simulation, trial documentation, and data monitoring committees are provided.

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.

Adaptive dose-response studies

Insufficient exploration of the dose-response is a shortcoming of clinical drug development, and failure to characterize dosing early is often cited as a key contributor to the high late-stage attrition rate currently faced by the industry. Adaptive methods, for example, make it feasible to design a proof-of-concept study as an adaptive dose-response trial. Efficient learning about the dose response earlier in development will ultimately reduce overall costs and provide better information on dose in the filing package. This article presents the Pharmaceutical Research and Manufacturers of America working groups main recommendations regarding adaptive dose-response studies. As background, traditional fixed and adaptive dose-response designs are briefly reviewed. Information on developing a Bayesian adaptive dose design and some monitoring and processing issues are also discussed.

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. Clinical Trials 2010; 7: 167—173. http://ctj.sagepub.com

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 PhRMAs workshop held in November 2006. We also provide a status report of workstreams within PhRMAs 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 PhRMAs working group on adaptive designs.

Dose-finding results in an adaptive, seamless, randomized trial of once-weekly dulaglutide combined with metformin in type 2 diabetes patients (AWARD-5)

AWARD‐5 was an adaptive, seamless, double‐blind study comparing dulaglutide, a once‐weekly glucagon‐like peptide‐1 (GLP‐1) receptor agonist, with placebo at 26 weeks and sitagliptin up to 104 weeks. The study also included a dose‐finding portion whose results are presented here.

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.

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.