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Jaki T, Burdon A, Chen X, Mozgunov P, Zheng H, Baird R. Early phase clinical trials in oncology: Realising the potential of seamless designs. Eur J Cancer 2023; 189:112916. [PMID: 37301716 PMCID: PMC7614750 DOI: 10.1016/j.ejca.2023.05.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 05/03/2023] [Accepted: 05/04/2023] [Indexed: 06/12/2023]
Abstract
BACKGROUND The pharmaceutical industry's productivity has been declining over the last two decades and high attrition rates and reduced regulatory approvals are being seen. The development of oncology drugs is particularly challenging with low rates of approval for novel treatments when compared with other therapeutic areas. Reliably establishing the potential of novel treatment and the corresponding optimal dosage is a key component to ensure efficient overall development. A growing interest lies in terminating developments of poor treatments quickly while enabling accelerated development for highly promising interventions. METHODS One approach to reliably establish the optimal dosage and the potential of a novel treatment and thereby improve efficiency in the drug development pathway is the use of novel statistical designs that make efficient use of the data collected. RESULTS In this paper, we discuss different (seamless) strategies for early oncology development and illustrate their strengths and weaknesses through real trial examples. We provide some directions for good practices in early oncology development, discuss frequently seen missed opportunities for improved efficiency and some future opportunities that have yet to fully develop their potential in early oncology treatment development. DISCUSSION Modern methods for dose-finding have the potential to shorten and improve dose-finding and only small changes to current approaches are required to realise this potential.
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Affiliation(s)
- Thomas Jaki
- MRC Biostatistics Unit, University of Cambridge, UK; University of Regensburg, Germany.
| | | | - Xijin Chen
- MRC Biostatistics Unit, University of Cambridge, UK
| | | | - Haiyan Zheng
- MRC Biostatistics Unit, University of Cambridge, UK
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2
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Labrenz J, Edelmann D, Heitmann JS, Salih HR, Kopp-Schneider A, Schlenk RF. Performance of phase-I dose finding designs with and without a run-in intra-patient dose escalation stage. Pharm Stat 2023; 22:236-247. [PMID: 36285348 DOI: 10.1002/pst.2268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 08/05/2022] [Accepted: 10/03/2022] [Indexed: 11/06/2022]
Abstract
Dose-finding designs for phase-I trials aim to determine the recommended phase-II dose (RP2D) for further phase-II drug development. If the trial includes patients for whom several lines of standard therapy failed or if the toxicity of the investigated agent does not necessarily increase with dose, optimal dose-finding designs should limit the frequency of treatment with suboptimal doses. We propose a two-stage design strategy with a run-in intra-patient dose escalation part followed by a more traditional dose-finding design. We conduct simulation studies to compare the 3 + 3 design, the Bayesian Optimal Interval Design (BOIN) and the Continual Reassessment Method (CRM) with and without intra-patient dose escalation. The endpoints are accuracy, sample size, safety, and therapeutic efficiency. For scenarios where the correct RP2D is the highest dose, inclusion of an intra-patient dose escalation stage generally increases accuracy and therapeutic efficiency. However, for scenarios where the correct RP2D is below the highest dose, intra-patient dose escalation designs lead to increased risk of overdosing and an overestimation of RP2D. The magnitude of the change in operating characteristics after including an intra-patient stage is largest for the 3 + 3 design, decreases for the BOIN and is smallest for the CRM.
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Affiliation(s)
- Jannik Labrenz
- NCT Trial Center, National Center for Tumor Diseases, German Cancer Research Center, Heidelberg, Germany
- Division of Biostatistics, German Cancer Research Center, Heidelberg, Germany
| | - Dominic Edelmann
- NCT Trial Center, National Center for Tumor Diseases, German Cancer Research Center, Heidelberg, Germany
- Division of Biostatistics, German Cancer Research Center, Heidelberg, Germany
| | - Jonas S Heitmann
- Clinical Collaboration Unit Translational Immunology, German Cancer Consortium (DKTK), Department of Internal Medicine, University Hospital Tübingen, Tübingen, Germany
| | - Helmut R Salih
- Clinical Collaboration Unit Translational Immunology, German Cancer Consortium (DKTK), Department of Internal Medicine, University Hospital Tübingen, Tübingen, Germany
| | | | - Richard F Schlenk
- NCT Trial Center, National Center for Tumor Diseases, German Cancer Research Center, Heidelberg, Germany
- Department of Internal Medicine V and Internal Medicine VI, Heidelberg University Hospital, Heidelberg, Germany
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Pantoja K, Lanke S, Munafo A, Victor A, Habermehl C, Schueler A, Venkatakrishnan K, Girard P, Goteti K. Designing phase I oncology dose escalation using dose-exposure-toxicity models as a complementary approach to model-based dose-toxicity models. CPT Pharmacometrics Syst Pharmacol 2022; 11:1371-1381. [PMID: 35852048 PMCID: PMC9574748 DOI: 10.1002/psp4.12851] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 07/05/2022] [Accepted: 07/11/2022] [Indexed: 11/29/2022] Open
Abstract
One of the objectives of oncology phase I dose-escalation studies has been to determine the maximum tolerated dose (MTD). Although MTD is no longer set as the dose for further development in contemporary oncology drug development, MTD determination is still important for informing the therapeutic index. Bayesian adaptive model-based designs are becoming mainstream in oncology first-in-human trials. Herein, we illustrate via simulations the use of systemic exposure in Bayesian adaptive dose-toxicity models to estimate MTD. We extend traditional dose-toxicity models to incorporate pharmacokinetic exposure, which provides information on exposure-toxicity relationships. We pursue dose escalation until the maximum tolerated exposure (corresponding to the MTD) is reached. By leveraging pharmacokinetics, dose escalation considers exposure and interindividual variability on a continuous rather than discrete domain, offering additional information for dose-escalation decisions. To demonstrate this, we generated 1000 simulations (starting dose of 1/25th the reference dose and six dose levels) for several different scenarios. Both rule-based and model-based designs were compared using metrics of potential safety, accuracy, and reliability. The mean results over simulations and different toxicity scenarios showed that model-based designs were better than rule-based methods and that exposure-toxicity model-based methods have the potential to valuably complement dose-toxicity model-based methods. Exposure-toxicity model-based methods had decreased underdose risk accompanied by a relatively smaller increase in overdose risk, resulting in improved net reliability. MTD estimation accuracy was compromised when exposure variability was large, emphasizing the importance of appropriate control of pharmacokinetic variability in phase I dose-escalation studies.
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Affiliation(s)
- Kristyn Pantoja
- Department of StatisticsTexas A&M UniversityCollege StationTexasUSA,EMD Serono Research InstituteBillericaMassachusettsUSA
| | - Shankar Lanke
- EMD Serono Research InstituteBillericaMassachusettsUSA
| | - Alain Munafo
- Merck Institute for PharmacometricsLausanneSwitzerland
| | | | | | | | | | - Pascal Girard
- Merck Institute for PharmacometricsLausanneSwitzerland
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Micallef S, Sostelly A, Zhu J, Baverel PG, Mercier F. Exposure driven dose escalation design with overdose control: Concept and first real life experience in an oncology phase I trial. Contemp Clin Trials Commun 2022; 26:100901. [PMID: 35198796 PMCID: PMC8851091 DOI: 10.1016/j.conctc.2022.100901] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 11/12/2021] [Accepted: 01/31/2022] [Indexed: 11/19/2022] Open
Abstract
Background Methods Results Conclusion Formally leverage pharmacokinetic data and modeling in dose escalation studies. Suitable for molecules with potential non-linear pharmacokinetic. Smarter dose escalation and more informative recommended phase 2 dose.
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Affiliation(s)
| | | | - Jiawen Zhu
- Biostatistics, Genentech, Inc., San Francisco, USA
| | - Paul G Baverel
- Clinical Pharmacology, F. Hoffmann-La Roche AG, Basel, Switzerland
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Ewings S, Saunders G, Jaki T, Mozgunov P. Practical recommendations for implementing a Bayesian adaptive phase I design during a pandemic. BMC Med Res Methodol 2022; 22:25. [PMID: 35057758 PMCID: PMC8771176 DOI: 10.1186/s12874-022-01512-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Accepted: 01/06/2022] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND Modern designs for dose-finding studies (e.g., model-based designs such as continual reassessment method) have been shown to substantially improve the ability to determine a suitable dose for efficacy testing when compared to traditional designs such as the 3 + 3 design. However, implementing such designs requires time and specialist knowledge. METHODS We present a practical approach to developing a model-based design to help support uptake of these methods; in particular, we lay out how to derive the necessary parameters and who should input, and when, to these decisions. Designing a model-based, dose-finding trial is demonstrated using a treatment within the AGILE platform trial, a phase I/II adaptive design for novel COVID-19 treatments. RESULTS We present discussion of the practical delivery of AGILE, covering what information was found to support principled decision making by the Safety Review Committee, and what could be contained within a statistical analysis plan. We also discuss additional challenges we encountered in the study and discuss more generally what (unplanned) adaptations may be acceptable (or not) in studies using model-based designs. CONCLUSIONS This example demonstrates both how to design and deliver an adaptive dose-finding trial in order to support uptake of these methods.
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Affiliation(s)
- Sean Ewings
- Southampton Clinical Trials Unit, University of Southampton, Mailpoint 131, Southampton General Hospital, Tremona Road, Southampton, SO16, UK.
| | - Geoff Saunders
- Southampton Clinical Trials Unit, University of Southampton, Mailpoint 131, Southampton General Hospital, Tremona Road, Southampton, SO16, UK
| | - Thomas Jaki
- MRC Biostatistics Unit, University of Cambridge, Cambridge, UK
- Department of Mathematics and Statistics, Lancaster University, University of Lancaster, Lancaster, UK
| | - Pavel Mozgunov
- MRC Biostatistics Unit, University of Cambridge, Cambridge, UK
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VanBuren JM, Casper TC, Nishijima DK, Kuppermann N, Lewis RJ, Dean JM, McGlothlin A. The design of a Bayesian adaptive clinical trial of tranexamic acid in severely injured children. Trials 2021; 22:769. [PMID: 34736498 PMCID: PMC8567588 DOI: 10.1186/s13063-021-05737-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Accepted: 10/20/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Trauma is the leading cause of death and disability in children in the USA. Tranexamic acid (TXA) reduces the blood transfusion requirements in adults and children during surgery. Several studies have evaluated TXA in adults with hemorrhagic trauma, but no randomized controlled trials have occurred in children with trauma. We propose a Bayesian adaptive clinical trial to investigate TXA in children with brain and/or torso hemorrhagic trauma. METHODS/DESIGN We designed a double-blind, Bayesian adaptive clinical trial that will enroll up to 2000 patients. We extend the traditional Emax dose-response model to incorporate a hierarchical structure so multiple doses of TXA can be evaluated in different injury populations (isolated head injury, isolated torso injury, or both head and torso injury). Up to 3 doses of TXA (15 mg/kg, 30 mg/kg, and 45 mg/kg bolus doses) will be compared to placebo. Equal allocation between placebo, 15 mg/kg, and 30 mg/kg will be used for an initial period within each injury group. Depending on the dose-response curve, the 45 mg/kg arm may open in an injury group if there is a trend towards increasing efficacy based on the observed relationship using the data from the lower doses. Response-adaptive randomization allows each injury group to differ in allocation proportions of TXA so an optimal dose can be identified for each injury group. Frequent interim stopping periods are included to evaluate efficacy and futility. The statistical design is evaluated through extensive simulations to determine the operating characteristics in several plausible scenarios. This trial achieves adequate power in each injury group. DISCUSSION This trial design evaluating TXA in pediatric hemorrhagic trauma allows for three separate injury populations to be analyzed and compared within a single study framework. Individual conclusions regarding optimal dosing of TXA can be made within each injury group. Identifying the optimal dose of TXA, if any, for various injury types in childhood may reduce death and disability.
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Affiliation(s)
- John M. VanBuren
- Department of Pediatrics, University of Utah School of Medicine, 295 Chipeta Way, Salt Lake City, UT 84108 USA
| | - T. Charles Casper
- Department of Pediatrics, University of Utah School of Medicine, 295 Chipeta Way, Salt Lake City, UT 84108 USA
| | - Daniel K. Nishijima
- Department of Emergency Medicine, University of California, Davis School of Medicine, Sacramento, CA 95817 USA
| | - Nathan Kuppermann
- Department of Emergency Medicine, University of California, Davis School of Medicine, Sacramento, CA 95817 USA
- Department of Pediatrics, University of California, Davis School of Medicine, Sacramento, CA 95817 USA
| | - Roger J. Lewis
- Department of Emergency Medicine, Harbor-UCLA Medical Center, Torrance, CA 90509 USA
- Berry Consultants, LLC, Austin, TX 78746 USA
| | - J. Michael Dean
- Department of Pediatrics, University of Utah School of Medicine, 295 Chipeta Way, Salt Lake City, UT 84108 USA
| | | | - For the TIC-TOC Collaborators of the Pediatric Emergency Care Applied Research Network (PECARN)
- Department of Pediatrics, University of Utah School of Medicine, 295 Chipeta Way, Salt Lake City, UT 84108 USA
- Department of Emergency Medicine, University of California, Davis School of Medicine, Sacramento, CA 95817 USA
- Department of Pediatrics, University of California, Davis School of Medicine, Sacramento, CA 95817 USA
- Department of Emergency Medicine, Harbor-UCLA Medical Center, Torrance, CA 90509 USA
- Berry Consultants, LLC, Austin, TX 78746 USA
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Issues in Designing and Interpreting Small Clinical Trials. Can J Cardiol 2021; 37:1332-1339. [PMID: 33775881 DOI: 10.1016/j.cjca.2021.03.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 03/17/2021] [Accepted: 03/18/2021] [Indexed: 11/23/2022] Open
Abstract
The randomised controlled trial (RCT) is a powerful approach for testing the effectiveness of various clinical interventions. Cardiology often benefits from large RCTs, which may be used to inform practice decisions ranging from primary prevention to advanced cardiac disease and/or acute cardiac care. RCTs in cardiology often need to be quite large to test for meaningful effects on clinical outcomes, because effect sizes are typically modest and clinical outcomes may take several years to occur after treatment initiation. However, a variety of small clinical trials are also carried out in the biomedical research enterprise; these are often difficult to design and interpret, because the objectives and needs of small clinical trials are quite variable. Some are pilot trials that may be used to refine processes or as part of the planning in advance of a larger trial designed to test therapeutic efficacy. Some are first-in-human or proof-of-concept studies that, also, will eventually be followed by one or more larger trials to test therapeutic efficacy. Some are intended to be stand-alone trials that are small for other reasons. In this paper, we explore some key issues related to design and interpretation of small clinical trials in cardiology. We broadly classify small trials into 4 types: 1) pilot trials, 2) early-stage or proof-of-concept trials, 3) rare diseases or difficult-to-recruit populations, and 4) underpowered trials. For each, we describe the appropriate objectives, analysis, and interpretation.
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8
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Takahashi A, Suzuki T. Bayesian optimization for estimating the maximum tolerated dose in Phase I clinical trials. Contemp Clin Trials Commun 2021; 21:100753. [PMID: 33681528 PMCID: PMC7910500 DOI: 10.1016/j.conctc.2021.100753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 11/26/2020] [Accepted: 02/09/2021] [Indexed: 11/26/2022] Open
Abstract
We introduce a Bayesian optimization method for estimating the maximum tolerated dose in this article. A number of parametric model-based methods have been proposed to estimate the maximum tolerated dose; however, parametric model-based methods need an assumption that dose-toxicity relationships follow specific theoretical models. This assumption potentially leads to suboptimal dose selections if the dose-toxicity curve is misspecified. Our proposed method is based on a Bayesian optimization framework for finding a global optimizer of unknown functions that are expensive to evaluate while using very few function evaluations. It models dose-toxicity relationships with a nonparametric model; therefore, a more flexible estimation can be realized compared with existing parametric model-based methods. Also, most existing methods rely on point estimates of dose-toxicity curves in their dose selections. In contrast, our proposed method exploits a probabilistic model for an unknown function to determine the next dose candidate without ignoring the uncertainty of posterior while imposing some dose-escalation limitations. We investigate the operating characteristics of our proposed method by comparing them with those of the Bayesian-based continual reassessment method and two different nonparametric methods. Simulation results suggest that our proposed method works successfully in terms of selections of the maximum tolerated dose correctly and safe dose allocations.
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Affiliation(s)
- Ami Takahashi
- Department of Mathematical and Computing Science, School of Computing, Tokyo Institute of Technology, Tokyo, Japan.,Biometrics and Data Management, Clinical Statistics, Pfizer R&D Japan, Tokyo, Japan
| | - Taiji Suzuki
- Department of Mathematical Informatics, Graduate School of Information Science and Technology, The University of Tokyo, Tokyo, Japan.,Center for Advanced Intelligence Project, RIKEN, Japan
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James GD, Symeonides S, Marshall J, Young J, Clack G. Assessment of various continual reassessment method models for dose-escalation phase 1 oncology clinical trials: using real clinical data and simulation studies. BMC Cancer 2021; 21:7. [PMID: 33402104 PMCID: PMC7786936 DOI: 10.1186/s12885-020-07703-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Accepted: 11/30/2020] [Indexed: 11/10/2022] Open
Abstract
Background The continual reassessment method (CRM) identifies the maximum tolerated dose (MTD) more efficiently and identifies the true MTD more frequently compared to standard methods such as the 3 + 3 method. An initial estimate of the dose-toxicity relationship (prior skeleton) is required, and there is limited guidance on how to select this. Previously, we compared the CRM with six different skeletons to the 3 + 3 method by conducting post-hoc analysis on a phase 1 oncology study (AZD3514), each CRM model reduced the number of patients allocated to suboptimal and toxic doses. This manuscript extends this work by assessing the ability of the 3 + 3 method and the CRM with different skeletons in determining the true MTD of various “true” dose-toxicity relationships. Methods One thousand studies were simulated for each “true” dose toxicity relationship considered, four were based on clinical trial data (AZD3514, AZD1208, AZD1480, AZD4877), and four were theoretical. The 3 + 3 method and 2-stage extended CRM with six skeletons were applied to identify the MTD, where the true MTD was considered as the largest dose where the probability of experiencing a dose limiting toxicity (DLT) is ≤33%. Results For every true dose-toxicity relationship, the CRM selected the MTD that matched the true MTD in a higher proportion of studies compared to the 3 + 3 method. The CRM overestimated the MTD in a higher proportion of simulations compared to the 3 + 3 method. The proportion of studies where the correct MTD was selected varied considerably between skeletons. For some true dose-toxicity relationships, some skeletons identified the true MTD in a higher proportion of scenarios compared to the skeleton that matched the true dose-toxicity relationship. Conclusion Through simulation, the CRM generally outperformed the 3 + 3 method for the clinical and theoretical true dose-toxicity relationships. It was observed that accurate estimates of the true skeleton do not always outperform a generic skeleton, therefore the application of wide confidence intervals may enable a generic skeleton to be used. Further work is needed to determine the optimum skeleton.
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Affiliation(s)
- G D James
- Medical Statistics Consultancy Ltd, London, W4 5XF, UK.
| | - S Symeonides
- Edinburgh Cancer Research Centre, IGMM, University of Edinburgh, Edinburgh, EH4 2XU, UK
| | - J Marshall
- Oncology Biometrics, Oncology R&D, AstraZeneca, Cambridge, UK
| | - J Young
- Aptus Clinical Ltd, Alderley Park, Macclesfield, Cheshire, SK10 4TF, UK
| | - G Clack
- Department of Oncology and Metabolism, University of Sheffield, Sheffield, UK
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10
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Burnett T, Mozgunov P, Pallmann P, Villar SS, Wheeler GM, Jaki T. Adding flexibility to clinical trial designs: an example-based guide to the practical use of adaptive designs. BMC Med 2020; 18:352. [PMID: 33208155 PMCID: PMC7677786 DOI: 10.1186/s12916-020-01808-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 10/07/2020] [Indexed: 12/18/2022] Open
Abstract
Adaptive designs for clinical trials permit alterations to a study in response to accumulating data in order to make trials more flexible, ethical, and efficient. These benefits are achieved while preserving the integrity and validity of the trial, through the pre-specification and proper adjustment for the possible alterations during the course of the trial. Despite much research in the statistical literature highlighting the potential advantages of adaptive designs over traditional fixed designs, the uptake of such methods in clinical research has been slow. One major reason for this is that different adaptations to trial designs, as well as their advantages and limitations, remain unfamiliar to large parts of the clinical community. The aim of this paper is to clarify where adaptive designs can be used to address specific questions of scientific interest; we introduce the main features of adaptive designs and commonly used terminology, highlighting their utility and pitfalls, and illustrate their use through case studies of adaptive trials ranging from early-phase dose escalation to confirmatory phase III studies.
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Affiliation(s)
- Thomas Burnett
- Department of Mathematics and Statistics, Lancaster University, Fylde College, Lancaster, LA1 4YF UK
| | - Pavel Mozgunov
- Department of Mathematics and Statistics, Lancaster University, Fylde College, Lancaster, LA1 4YF UK
| | - Philip Pallmann
- Centre for Trials Research, College of Biomedical & Life Sciences, Cardiff University, Cardiff, UK
| | - Sofia S. Villar
- MRC Biostatistics Unit, University of Cambridge School of Clinical Medicine, Cambridge Institute of Public Health, Forvie Site, Robinson Way, Cambridge Biomedical Campus, Cambridge, CB2 0SR UK
| | - Graham M. Wheeler
- Cancer Research UK & UCL Cancer Trials Centre, University College London, 90 Tottenham Court Road, London, W1T 4TJ UK
| | - Thomas Jaki
- Department of Mathematics and Statistics, Lancaster University, Fylde College, Lancaster, LA1 4YF UK
- MRC Biostatistics Unit, University of Cambridge School of Clinical Medicine, Cambridge Institute of Public Health, Forvie Site, Robinson Way, Cambridge Biomedical Campus, Cambridge, CB2 0SR UK
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11
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Clinical development of cell therapies for cancer: The regulators' perspective. Eur J Cancer 2020; 138:41-53. [PMID: 32836173 DOI: 10.1016/j.ejca.2020.07.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Accepted: 07/04/2020] [Indexed: 11/21/2022]
Abstract
Novel cell therapies for haematological malignancies and solid tumours address pressing clinical need while offering potentially paradigm shifts in efficacy. However, innovative development risks outflanking information on statutory frameworks, regulatory guidelines and their working application. Meeting this challenge, regulators offer wide-ranging expertise and experience in confidential scientific and regulatory advice. We advocate early incorporation of regulatory perspectives to support strategic development of clinical programmes. We examine critical issues and key advances in clinical oncology trials to highlight practical approaches to optimising the clinical development of cell therapies. We recommend early consideration of collaborative networks, early-access schemes, reducing bias in single-arm trials, adaptive trials, clinical end-points supporting risk/benefit and cost/benefit analyses, companion diagnostics, real-world data and common technical issues. This symbiotic approach between developers and regulators should reduce development risk, safely expedite marketing authorisation, and promote early, wider availability of potentially transformative cell therapies for cancer.
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12
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Pallmann P, Wan F, Mander AP, Wheeler GM, Yap C, Clive S, Hampson LV, Jaki T. Designing and evaluating dose-escalation studies made easy: The MoDEsT web app. Clin Trials 2020; 17:147-156. [PMID: 31856600 PMCID: PMC7227124 DOI: 10.1177/1740774519890146] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND/AIMS Dose-escalation studies are essential in the early stages of developing novel treatments, when the aim is to find a safe dose for administration in humans. Despite their great importance, many dose-escalation studies use study designs based on heuristic algorithms with well-documented drawbacks. Bayesian decision procedures provide a design alternative that is conceptually simple and methodologically sound, but very rarely used in practice, at least in part due to their perceived statistical complexity. There are currently very few easily accessible software implementations that would facilitate their application. METHODS We have created MoDEsT, a free and easy-to-use web application for designing and conducting single-agent dose-escalation studies with a binary toxicity endpoint, where the objective is to estimate the maximum tolerated dose. MoDEsT uses a well-established Bayesian decision procedure based on logistic regression. The software has a user-friendly point-and-click interface, makes changes visible in real time, and automatically generates a range of graphs, tables, and reports. It is aimed at clinicians as well as statisticians with limited expertise in model-based dose-escalation designs, and does not require any statistical programming skills to evaluate the operating characteristics of, or implement, the Bayesian dose-escalation design. RESULTS MoDEsT comes in two parts: a 'Design' module to explore design options and simulate their operating characteristics, and a 'Conduct' module to guide the dose-finding process throughout the study. We illustrate the practical use of both modules with data from a real phase I study in terminal cancer. CONCLUSION Enabling both methodologists and clinicians to understand and apply model-based study designs with ease is a key factor towards their routine use in early-phase studies. We hope that MoDEsT will enable incorporation of Bayesian decision procedures for dose escalation at the earliest stage of clinical trial design, thus increasing their use in early-phase trials.
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Affiliation(s)
- Philip Pallmann
- Centre for Trials Research, College of Biomedical & Life Sciences, Cardiff University, Cardiff, UK
| | - Fang Wan
- Department of Mathematics & Statistics, Lancaster University, Lancaster, UK
| | - Adrian P Mander
- Centre for Trials Research, College of Biomedical & Life Sciences, Cardiff University, Cardiff, UK
- MRC Biostatistics Unit, University of Cambridge, Cambridge, UK
| | - Graham M Wheeler
- MRC Biostatistics Unit, University of Cambridge, Cambridge, UK
- Cancer Research UK & UCL Cancer Trials Centre, University College London, London, UK
| | - Christina Yap
- Cancer Research UK Clinical Trials Unit, University of Birmingham, Birmingham, UK
| | - Sally Clive
- Edinburgh Cancer Centre, Western General Hospital, Edinburgh, UK
| | - Lisa V Hampson
- Statistical Methodology, Novartis Pharma AG, Basel, Switzerland
| | - Thomas Jaki
- Department of Mathematics & Statistics, Lancaster University, Lancaster, UK
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13
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Zheng H, Hampson LV, Wandel S. A robust Bayesian meta-analytic approach to incorporate animal data into phase I oncology trials. Stat Methods Med Res 2020; 29:94-110. [PMID: 30648481 DOI: 10.1177/0962280218820040] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Before a first-in-man trial is conducted, preclinical studies are performed in animals to help characterise the safety profile of the new medicine. We propose a robust Bayesian hierarchical model to synthesise animal and human toxicity data, using scaling factors to translate doses administered to different animal species onto an equivalent human scale. After scaling doses, the parameters of dose-toxicity models intrinsic to different animal species can be interpreted on a common scale. A prior distribution is specified for each translation factor to capture uncertainty about differences between toxicity of the drug in animals and humans. Information from animals can then be leveraged to learn about the relationship between dose and risk of toxicity in a new phase I trial in humans. The model allows human dose-toxicity parameters to be exchangeable with the study-specific parameters of animal species studied so far or non-exchangeable with any of them. This leads to robust inferences, enabling the model to give greatest weight to the animal data with parameters most consistent with human parameters or discount all animal data in the case of non-exchangeability. The proposed model is illustrated using a case study and simulations. Numerical results suggest that our proposal improves the precision of estimates of the toxicity rates when animal and human data are consistent, while it discounts animal data in cases of inconsistency.
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Affiliation(s)
- Haiyan Zheng
- Department of Mathematics and Statistics, Lancaster University, Lancaster, UK
| | - Lisa V Hampson
- Statistical Methodology and Consulting, Novartis Pharma AG, Basel, Switzerland
| | - Simon Wandel
- Statistical Methodology and Consulting, Novartis Pharma AG, Basel, Switzerland
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14
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Imamura K, Izumi Y, Banno H, Uozumi R, Morita S, Egawa N, Ayaki T, Nagai M, Nishiyama K, Watanabe Y, Hanajima R, Oki R, Fujita K, Takahashi N, Ikeda T, Shimizu A, Morinaga A, Hirohashi T, Fujii Y, Takahashi R, Inoue H. Induced pluripotent stem cell-based Drug Repurposing for Amyotrophic lateral sclerosis Medicine (iDReAM) study: protocol for a phase I dose escalation study of bosutinib for amyotrophic lateral sclerosis patients. BMJ Open 2019; 9:e033131. [PMID: 31796494 PMCID: PMC7003406 DOI: 10.1136/bmjopen-2019-033131] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
INTRODUCTION Amyotrophic lateral sclerosis (ALS) is a progressive and severe neurodegenerative disease caused by motor neuron death. There have as yet been no fundamental curative medicines, and the development of a medicine for ALS is urgently required. Induced pluripotent stem cell (iPSC)-based drug repurposing identified an Src/c-Abl inhibitor, bosutinib, as a candidate molecular targeted therapy for ALS. The objectives of this study are to evaluate the safety and tolerability of bosutinib for the treatment of patients with ALS and to explore the efficacy of bosutinib on ALS. This study is the first clinical trial of administered bosutinib for patients with ALS. METHODS AND ANALYSIS An open-label, multicentre phase I dose escalation study has been designed. The study consists of a 12-week observation period, a 1-week transitional period, a 12-week study treatment period and a 4-week follow-up period. After completion of the transitional period, subjects whose total ALS Functional Rating Scale-Revised (ALSFRS-R) score decreased by 1-3 points during the 12-week observation period receive bosutinib for 12 weeks. Three to six patients with ALS are enrolled in each of the four bosutinib dose levels (100, 200, 300 or 400 mg/day) to evaluate the safety and tolerability under a 3+3 dose escalation study design. Dose escalation and maximum tolerated dose are determined by the safety assessment committee comprising oncologists/haematologists and neurologists based on the incidence of dose-limiting toxicity in the first 4 weeks of the treatment at each dose level. A recommended phase II dose is determined by the safety assessment committee on completion of the 12-week study treatment in all subjects at all dose levels. The efficacy of bosutinib is also evaluated exploratorily using ALS clinical scores and biomarkers. ETHICS AND DISSEMINATION This study received full ethical approval from the institutional review board of each participating site. The findings of the study will be disseminated in peer-reviewed journals and at scientific conferences. TRIAL REGISTRATION NUMBER UMIN000036295; Pre-results, JMA-IIA00419; Pre-results.
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Affiliation(s)
- Keiko Imamura
- Center for iPS Cell Research and Application (CiRA), Kyoto University, Kyoto, Japan
| | - Yuishin Izumi
- Department of Neurology, Tokushima University Graduate School of Biomedical Sciences, Tokushima, Japan
| | - Haruhiko Banno
- Center for iPS Cell Research and Application (CiRA), Kyoto University, Kyoto, Japan
| | - Ryuji Uozumi
- Department of Biomedical Statistics and Bioinformatics, Kyoto University, Kyoto, Japan
| | - Satoshi Morita
- Department of Biomedical Statistics and Bioinformatics, Kyoto University, Kyoto, Japan
| | - Naohiro Egawa
- Department of Neurology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Takashi Ayaki
- Department of Neurology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Makiko Nagai
- Department of Neurology, Kitasato University School of Medicine, Sagamihara, Japan
| | - Kazutoshi Nishiyama
- Department of Neurology, Kitasato University School of Medicine, Sagamihara, Japan
| | - Yasuhiro Watanabe
- Division of Neurology, Department of Brain and Neurosciences, Faculty of Medicine, Tottori University, Yonago, Japan
| | - Ritsuko Hanajima
- Division of Neurology, Department of Brain and Neurosciences, Faculty of Medicine, Tottori University, Yonago, Japan
| | - Ryosuke Oki
- Department of Neurology, Tokushima University Graduate School of Biomedical Sciences, Tokushima, Japan
| | - Koji Fujita
- Department of Neurology, Tokushima University Graduate School of Biomedical Sciences, Tokushima, Japan
| | - Naoto Takahashi
- Department of Hematology, Nephrology, and Rheumatology, Akita University Graduate School of Medicine, Akita, Japan
| | - Takafumi Ikeda
- Institute for Advancement of Clinical and Translational Science (iACT), Kyoto University Hospital, Kyoto, Japan
| | - Akira Shimizu
- Institute for Advancement of Clinical and Translational Science (iACT), Kyoto University Hospital, Kyoto, Japan
| | | | | | | | - Ryosuke Takahashi
- Department of Neurology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Haruhisa Inoue
- Center for iPS Cell Research and Application (CiRA), Kyoto University, Kyoto, Japan
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15
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Zhu Y, Hwang WT, Li Y. Evaluating the effects of design parameters on the performances of phase I trial designs. Contemp Clin Trials Commun 2019; 15:100379. [PMID: 31193764 PMCID: PMC6543020 DOI: 10.1016/j.conctc.2019.100379] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Revised: 04/30/2019] [Accepted: 05/15/2019] [Indexed: 11/28/2022] Open
Abstract
Numerous designs have been proposed for phase I clinical trials. Although studies have compared their performances, few have considered the effects of changing design parameters. In this article, we review a few popular designs, including the 3 + 3, continuous reassessment method (CRM), Bayesian optimal interval (BOIN) design, and Keyboard design, and evaluate how varying design parameters (such as number of dose levels, target toxicity rate, maximum sample size, and cohort size) could impact the performances of each design through simulations. Excluded from our analysis is the mTPI-2 design, which operates in the same way as the Keyboard. Our results suggest that regardless of the choices of design parameters, the 3 + 3 design performs worse than the other ones, and BOIN and Keyboard have comparable performance to CRM. For any design, the performance varies with the choice of parameters. In particular, it improves as sample sizes increase, but the magnitude of benefit from increasing sample sizes varies substantially across scenarios. The impact of cohort size on design performances seems to have no clear direction. Therefore, BOIN and Keyboard designs are generally recommended due to their simplicity and good performance. With regard to choices of sample size and cohort size in designing a trial, it is recommend that simulations be performed for the particular clinical settings to aid decision making.
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Affiliation(s)
- Yaqian Zhu
- Department of Biostatistics, Epidemiology and Informatics, University of Pennsylvania, Philadelphia, PA, USA
| | - Wei-Ting Hwang
- Department of Biostatistics, Epidemiology and Informatics, University of Pennsylvania, Philadelphia, PA, USA
| | - Yimei Li
- Department of Biostatistics, Epidemiology and Informatics, University of Pennsylvania, Philadelphia, PA, USA
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16
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Horton BJ, O'Quigley J, Conaway MR. Consequences of Performing Parallel Dose Finding Trials in Heterogeneous Groups of Patients. JNCI Cancer Spectr 2019; 3:pkz013. [PMID: 31206097 PMCID: PMC6555302 DOI: 10.1093/jncics/pkz013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Revised: 02/01/2019] [Accepted: 03/18/2019] [Indexed: 11/13/2022] Open
Abstract
Patient heterogeneity, in which patients can be grouped by risk of toxicity, is a design challenge in early phase dose finding trials. Carrying out independent trials for each group is a readily available approach for dose finding. However, this often leads to dose recommendations that violate the known order of toxicity risk by group, or reversals in dose recommendation. In this manuscript, trials for partially ordered groups are simulated using four approaches: independent parallel trials using the continual reassessment method (CRM), Bayesian optimal interval design, and 3 + 3 methods, as well as CRM for partially ordered groups. Multiple group order structures are considered, allowing for varying amounts of group frailty order information. These simulations find that parallel trials in the presence of partially ordered groups display a high frequency of trials resulting in reversals. Reversals occur when dose recommendations do not follow known order of toxicity risk by group, such as recommending a higher dose level in a group of patients known to have a higher risk of toxicity. CRM for partially ordered groups eliminates the issue of reversals, and simulation results indicate improved frequency of maximum tolerated dose selection as well as treating a greater proportion of trial patients at this dose compared with parallel trials. When information is available on differences in toxicity risk by patient subgroup, methods designed to account for known group ordering should be considered to avoid reversals in dose recommendations and improve operating characteristics.
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Affiliation(s)
- Bethany Jablonski Horton
- Division of Translational Research and Applied Statistics, Department of Public Health Sciences, University of Virginia, Charlottesville, VA
| | | | - Mark R Conaway
- Division of Translational Research and Applied Statistics, Department of Public Health Sciences, University of Virginia, Charlottesville, VA
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17
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Wheeler GM, Mander AP, Bedding A, Brock K, Cornelius V, Grieve AP, Jaki T, Love SB, Odondi L, Weir CJ, Yap C, Bond SJ. How to design a dose-finding study using the continual reassessment method. BMC Med Res Methodol 2019; 19:18. [PMID: 30658575 PMCID: PMC6339349 DOI: 10.1186/s12874-018-0638-z] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Accepted: 12/06/2018] [Indexed: 11/16/2022] Open
Abstract
INTRODUCTION The continual reassessment method (CRM) is a model-based design for phase I trials, which aims to find the maximum tolerated dose (MTD) of a new therapy. The CRM has been shown to be more accurate in targeting the MTD than traditional rule-based approaches such as the 3 + 3 design, which is used in most phase I trials. Furthermore, the CRM has been shown to assign more trial participants at or close to the MTD than the 3 + 3 design. However, the CRM's uptake in clinical research has been incredibly slow, putting trial participants, drug development and patients at risk. Barriers to increasing the use of the CRM have been identified, most notably a lack of knowledge amongst clinicians and statisticians on how to apply new designs in practice. No recent tutorial, guidelines, or recommendations for clinicians on conducting dose-finding studies using the CRM are available. Furthermore, practical resources to support clinicians considering the CRM for their trials are scarce. METHODS To help overcome these barriers, we present a structured framework for designing a dose-finding study using the CRM. We give recommendations for key design parameters and advise on conducting pre-trial simulation work to tailor the design to a specific trial. We provide practical tools to support clinicians and statisticians, including software recommendations, and template text and tables that can be edited and inserted into a trial protocol. We also give guidance on how to conduct and report dose-finding studies using the CRM. RESULTS An initial set of design recommendations are provided to kick-start the design process. To complement these and the additional resources, we describe two published dose-finding trials that used the CRM. We discuss their designs, how they were conducted and analysed, and compare them to what would have happened under a 3 + 3 design. CONCLUSIONS The framework and resources we provide are aimed at clinicians and statisticians new to the CRM design. Provision of key resources in this contemporary guidance paper will hopefully improve the uptake of the CRM in phase I dose-finding trials.
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Affiliation(s)
- Graham M. Wheeler
- Cancer Research UK and UCL Cancer Trials Centre, University College London, 90 Tottenham Court Road, London, W1T 4TJ UK
| | - Adrian P. Mander
- MRC Biostatistics Unit Hub for Trials Methodology Research, University of Cambridge, Cambridge Institute of Public Health, Forvie Site, Robinson Way, Cambridge Biomedical Campus, Cambridge, CB2 0SR UK
| | - Alun Bedding
- Roche Pharmaceuticals, Hexagon Place, Falcon Way, Shire Park, Welwyn Garden City, AL7 1TW UK
| | - Kristian Brock
- Cancer Research UK Clinical Trials Unit, Institute of Cancer and Genomic Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT UK
| | - Victoria Cornelius
- School of Public Health, Imperial College London, 68 Wood Lane, London, W12 7RH UK
| | | | - Thomas Jaki
- Department of Mathematics and Statistics, Fylde College, Lancaster University, Fylde Avenue, Bailrigg, Lancaster, LA1 4YF UK
| | - Sharon B. Love
- Oxford Clinical Trials Research Unit, Centre for Statistics in Medicine, NDORMS, University of Oxford, Botnar Research Centre, Windmill Road, Oxford, OX3 7LD UK
- MRC Clinical Trials Unit, University College London, 90 High Holborn, London, WC1V 6LJ UK
| | - Lang’o Odondi
- Oxford Clinical Trials Research Unit, Centre for Statistics in Medicine, NDORMS, University of Oxford, Botnar Research Centre, Windmill Road, Oxford, OX3 7LD UK
| | - Christopher J. Weir
- Edinburgh Clinical Trials Unit, Usher Institute of Population Health Sciences, University of Edinburgh, Nine Edinburgh Bioquarter, 9 Little France Road, Edinburgh, EH16 4UX UK
| | - Christina Yap
- Cancer Research UK Clinical Trials Unit, Institute of Cancer and Genomic Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT UK
| | - Simon J. Bond
- MRC Biostatistics Unit Hub for Trials Methodology Research, University of Cambridge, Cambridge Institute of Public Health, Forvie Site, Robinson Way, Cambridge Biomedical Campus, Cambridge, CB2 0SR UK
- National Institute for Health Research Cambridge Clinical Trials Unit, Cambridge University Hospitals NHS Foundation Trust, Addenbrooke’s Hospital, Hills Road, Cambridge Biomedical Campus, Box 401, Coton House Level 6, Cambridge, CB2 0QQ UK
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18
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Cotterill A, Jaki T. Dose-escalation strategies which use subgroup information. Pharm Stat 2018; 17:414-436. [PMID: 29900666 PMCID: PMC6175353 DOI: 10.1002/pst.1860] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Revised: 01/30/2018] [Accepted: 02/26/2018] [Indexed: 12/04/2022]
Abstract
Dose-escalation trials commonly assume a homogeneous trial population to identify a single recommended dose of the experimental treatment for use in future trials. Wrongly assuming a homogeneous population can lead to a diluted treatment effect. Equally, exclusion of a subgroup that could in fact benefit from the treatment can cause a beneficial treatment effect to be missed. Accounting for a potential subgroup effect (ie, difference in reaction to the treatment between subgroups) in dose-escalation can increase the chance of finding the treatment to be efficacious in a larger patient population. A standard Bayesian model-based method of dose-escalation is extended to account for a subgroup effect by including covariates for subgroup membership in the dose-toxicity model. A stratified design performs well but uses available data inefficiently and makes no inferences concerning presence of a subgroup effect. A hypothesis test could potentially rectify this problem but the small sample sizes result in a low-powered test. As an alternative, the use of spike and slab priors for variable selection is proposed. This method continually assesses the presence of a subgroup effect, enabling efficient use of the available trial data throughout escalation and in identifying the recommended dose(s). A simulation study, based on real trial data, was conducted and this design was found to be both promising and feasible.
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Affiliation(s)
- Amy Cotterill
- Cancer Research UK Clinical Trials Unit, Institute of Cancer and Genomic SciencesUniversity of BirminghamBirminghamUK
| | - Thomas Jaki
- Medical and Pharmaceutical Statistics Research Unit, Department of Mathematics and StatisticsLancaster UniversityLancasterUK
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19
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Braun TM. Motivating sample sizes in adaptive Phase I trials via Bayesian posterior credible intervals. Biometrics 2018. [PMID: 29534298 DOI: 10.1111/biom.12872] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
In contrast with typical Phase III clinical trials, there is little existing methodology for determining the appropriate numbers of patients to enroll in adaptive Phase I trials. And, as stated by Dennis Lindley in a more general context, "[t]he simple practical question of 'What size of sample should I take' is often posed to a statistician, and it is a question that is embarrassingly difficult to answer." Historically, simulation has been the primary option for determining sample sizes for adaptive Phase I trials, and although useful, can be problematic and time-consuming when a sample size is needed relatively quickly. We propose a computationally fast and simple approach that uses Beta distributions to approximate the posterior distributions of DLT rates of each dose and determines an appropriate sample size through posterior coverage rates. We provide sample sizes produced by our methods for a vast number of realistic Phase I trial settings and demonstrate that our sample sizes are generally larger than those produced by a competing approach that is based upon the nonparametric optimal design.
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Affiliation(s)
- Thomas M Braun
- Department of Biostatistics, School of Public Health, University of Michigan, Ann Arbor, Michigan, U.S.A
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20
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Love SB, Brown S, Weir CJ, Harbron C, Yap C, Gaschler-Markefski B, Matcham J, Caffrey L, McKevitt C, Clive S, Craddock C, Spicer J, Cornelius V. Embracing model-based designs for dose-finding trials. Br J Cancer 2017; 117:332-339. [PMID: 28664918 PMCID: PMC5537496 DOI: 10.1038/bjc.2017.186] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Revised: 04/27/2017] [Accepted: 05/31/2017] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Dose-finding trials are essential to drug development as they establish recommended doses for later-phase testing. We aim to motivate wider use of model-based designs for dose finding, such as the continual reassessment method (CRM). METHODS We carried out a literature review of dose-finding designs and conducted a survey to identify perceived barriers to their implementation. RESULTS We describe the benefits of model-based designs (flexibility, superior operating characteristics, extended scope), their current uptake, and existing resources. The most prominent barriers to implementation of a model-based design were lack of suitable training, chief investigators' preference for algorithm-based designs (e.g., 3+3), and limited resources for study design before funding. We use a real-world example to illustrate how these barriers can be overcome. CONCLUSIONS There is overwhelming evidence for the benefits of CRM. Many leading pharmaceutical companies routinely implement model-based designs. Our analysis identified barriers for academic statisticians and clinical academics in mirroring the progress industry has made in trial design. Unified support from funders, regulators, and journal editors could result in more accurate doses for later-phase testing, and increase the efficiency and success of clinical drug development. We give recommendations for increasing the uptake of model-based designs for dose-finding trials in academia.
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Affiliation(s)
- Sharon B Love
- Oxford Clinical Trials Research Unit, Centre for Statistics in Medicine, NDORMS, University of Oxford, Botnar Research Centre, Windmill Road, Oxford OX3 7LD, UK
| | - Sarah Brown
- Clinical Trials Research Unit, Leeds Institute of Clinical Trials Research, University of Leeds, Leeds LS2 9JT, UK
| | - Christopher J Weir
- Edinburgh Clinical Trials Unit, Usher Institute of Population Health Sciences and Informatics, University of Edinburgh Medical School, Teviot Place, Edinburgh EH8 9AG, UK
| | - Chris Harbron
- Roche Pharmaceuticals, 6 Falcon Way, Shire Park, Welwyn Garden City AL7 1TW, UK
| | - Christina Yap
- Cancer Research UK Clinical Trials Unit, Institute of Cancer and Genomic Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham B15 2TT, UK
| | - Birgit Gaschler-Markefski
- Boehringer Ingelheim Pharma GmbH & Co. KG, Biostatistics and Data Sciences, Birkendorfer Strasse 65, Biberach an der Riss 88400, Germany
| | - James Matcham
- AstraZeneca, DaVinci Building, Melbourn Science Park, Royston SG8 6HB, UK
| | - Louise Caffrey
- School of Social Work and Social Policy, Trinity College Dublin, College Green, Dublin 2, Ireland
| | - Christopher McKevitt
- Division of Health and Social Care Research, Faculty of Life Sciences and Medicine, King’s College London, London, UK
| | - Sally Clive
- Edinburgh Cancer Centre, Western General Hospital, Edinburgh EX4 2XU, UK
| | - Charlie Craddock
- Centre for Clinical Haematology, Haematology – University Hospitals Birmingham NHS Foundation Trust, Queen Elizabeth Hospital, Queen Elizabeth Medical Centre, Birmingham B15 2TH, UK
| | - James Spicer
- Division of Cancer Studies, Bermondsey Wing, Guy’s Hospital, Great Maze Pond, London SE1 9RT, UK
| | - Victoria Cornelius
- Imperial Clinical Trials Unit, Imperial College London, Stadium House, 68 Wood Lane, London W12 7RH, UK
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21
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Yan F, Mandrekar SJ, Yuan Y. Keyboard: A Novel Bayesian Toxicity Probability Interval Design for Phase I Clinical Trials. Clin Cancer Res 2017; 23:3994-4003. [PMID: 28546227 DOI: 10.1158/1078-0432.ccr-17-0220] [Citation(s) in RCA: 94] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Revised: 03/21/2017] [Accepted: 05/22/2017] [Indexed: 11/16/2022]
Abstract
The primary objective of phase I oncology trials is to find the MTD. The 3+3 design is easy to implement but performs poorly in finding the MTD. A newer design, such as the modified toxicity probability interval (mTPI) design, provides better accuracy to identify the MTD but tends to overdose patients. We propose the keyboard design, an intuitive Bayesian design that conducts dose escalation and de-escalation based on whether the strongest key, defined as the dosing interval that most likely contains the current dose, is below or above the target dosing interval. The keyboard design can be implemented in a simple way, similar to the traditional 3+3 design, but provides more flexibility for choosing the target toxicity rate and cohort size. Our simulation studies demonstrate that compared with the 3+3 design, the keyboard design has favorable operating characteristics in terms of identifying the MTD. Compared with the mTPI design, the keyboard design is safer, with a substantially lower risk of treating patients at overly toxic doses, and has the better precision to identify the MTD, thereby providing a useful upgrade to the mTPI design. Software freely available at http://www.trialdesign.org facilitates the application of the keyboard design. Clin Cancer Res; 23(15); 3994-4003. ©2017 AACRSee related commentary by Paoletti et al., p. 3977.
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Affiliation(s)
- Fangrong Yan
- Division of Biostatistics, China Pharmaceutical University, Nanjing, China
| | - Sumithra J Mandrekar
- Division of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, Minnesota
| | - Ying Yuan
- The University of Texas MD Anderson Cancer Center, Houston, Texas.
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22
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Brown SR, Sherratt D, Booth G, Brown J, Collinson F, Gregory W, Flanagan L. Experiences of establishing an academic early phase clinical trials unit. Clin Trials 2017; 14:349-356. [PMID: 28532202 DOI: 10.1177/1740774517710250] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Early phase trials are essential in drug development, determining appropriate dose levels and assessing preliminary activity. These trials are undertaken by industry and academia, with increasing collaborations between the two. There is pressure to perform these trials quickly, safely, and robustly. However, there are inherent differences between developing and managing early phase, compared to late phase, drug trials. This article describes an approach to establishing an academically led early phase trial portfolio, highlighting lessons learned and sharing experiences. METHODS In 2009, the University of Leeds Clinical Trials Research Unit became the Clinical Trials Coordinating Office for Myeloma UK's phase I and II trials. We embarked on a transition from working extensively in phase III to early phase trials development and conduct. This involved evaluating and revising our well-established standard operating procedures, visiting other academic early phase units, and developing essential new documentation and processes. RESULTS A core team of trial and data managers and statisticians was established to facilitate expertise and knowledge retention. A detailed training plan was implemented focussing on essential standard practices for early phase. These included pharmacovigilance, recruitment, trial design and set-up, data and site monitoring, and oversight committees. Training in statistical methods for early phase trials was incorporated. CONCLUSION Initial scoping of early phase trial management and conduct was essential in establishing this early phase portfolio. Many of the processes developed were successful. However, regular review and evaluation were implemented to enable changes and ensure efficiencies. It is recommended that others embarking on this venture build on the experiences described in this article.
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Affiliation(s)
- Sarah R Brown
- Leeds Institute of Clinical Trials Research (LICTR), University of Leeds, Leeds, UK
| | - Debbie Sherratt
- Leeds Institute of Clinical Trials Research (LICTR), University of Leeds, Leeds, UK
| | - Gill Booth
- Leeds Institute of Clinical Trials Research (LICTR), University of Leeds, Leeds, UK
| | - Julia Brown
- Leeds Institute of Clinical Trials Research (LICTR), University of Leeds, Leeds, UK
| | - Fiona Collinson
- Leeds Institute of Clinical Trials Research (LICTR), University of Leeds, Leeds, UK
| | - Walter Gregory
- Leeds Institute of Clinical Trials Research (LICTR), University of Leeds, Leeds, UK
| | - Louise Flanagan
- Leeds Institute of Clinical Trials Research (LICTR), University of Leeds, Leeds, UK
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23
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Systematic comparison of the statistical operating characteristics of various Phase I oncology designs. Contemp Clin Trials Commun 2016; 5:34-48. [PMID: 29740620 PMCID: PMC5936704 DOI: 10.1016/j.conctc.2016.11.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2016] [Revised: 11/16/2016] [Accepted: 11/22/2016] [Indexed: 11/21/2022] Open
Abstract
Dose finding Phase I oncology designs can be broadly categorized as rule based, such as the 3 + 3 and the accelerated titration designs, or model based, such as the CRM and Eff-Tox designs. This paper systematically reviews and compares through simulations several statistical operating characteristics, including the accuracy of maximum tolerated dose (MTD) selection, the percentage of patients assigned to the MTD, over-dosing, under-dosing, and the trial dose-limiting toxicity (DLT) rate, of eleven rule-based and model-based Phase I oncology designs that target or pre-specify a DLT rate of ∼0.2, for three sets of true DLT probabilities. These DLT probabilities are generated at common dosages from specific linear, logistic, and log-logistic dose-toxicity curves. We find that all the designs examined select the MTD much more accurately when there is a clear separation between the true DLT rate at the MTD and the rates at the dose level immediately above and below it, such as for the DLT rates generated using the chosen logistic dose-toxicity curve; the separations in these true DLT rates depend, in turn, not only on the functional form of the dose-toxicity curve but also on the investigated dose levels and the parameter set-up. The model based mTPI, TEQR, BOIN, CRM and EWOC designs perform well and assign the greatest percentages of patients to the MTD, and also have a reasonably high probability of picking the true MTD across the three dose-toxicity curves examined. Among the rule-based designs studied, the 5 + 5 a design picks the MTD as accurately as the model based designs for the true DLT rates generated using the chosen log-logistic and linear dose-toxicity curves, but requires enrolling a higher number of patients than the other designs. We also find that it is critical to pick a design that is aligned with the true DLT rate of interest. Further, we note that Phase I trials are very small in general and hence may not provide accurate estimates of the MTD. Thus our work provides a map for planning Phase I oncology trials or developing new ones.
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24
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Collins DC, Sundar R, Lim JSJ, Yap TA. Towards Precision Medicine in the Clinic: From Biomarker Discovery to Novel Therapeutics. Trends Pharmacol Sci 2016; 38:25-40. [PMID: 27871777 DOI: 10.1016/j.tips.2016.10.012] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Revised: 10/18/2016] [Accepted: 10/19/2016] [Indexed: 02/08/2023]
Abstract
Precision medicine continues to be the benchmark to which we strive in cancer research. Seeking out actionable aberrations that can be selectively targeted by drug compounds promises to optimize treatment efficacy and minimize toxicity. Utilizing these different targeted agents in combination or in sequence may further delay resistance to treatments and prolong antitumor responses. Remarkable progress in the field of immunotherapy adds another layer of complexity to the management of cancer patients. Corresponding advances in companion biomarker development, novel methods of serial tumor assessments, and innovative trial designs act synergistically to further precision medicine. Ongoing hurdles such as clonal evolution, intra- and intertumor heterogeneity, and varied mechanisms of drug resistance continue to be challenges to overcome. Large-scale data-sharing and collaborative networks using next-generation sequencing (NGS) platforms promise to take us further into the cancer 'ome' than ever before, with the goal of achieving successful precision medicine.
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Affiliation(s)
- Dearbhaile C Collins
- The Institute of Cancer Research and Royal Marsden Hospital, Downs Road, London SM2 5PT, UK
| | - Raghav Sundar
- The Institute of Cancer Research and Royal Marsden Hospital, Downs Road, London SM2 5PT, UK
| | - Joline S J Lim
- The Institute of Cancer Research and Royal Marsden Hospital, Downs Road, London SM2 5PT, UK
| | - Timothy A Yap
- The Institute of Cancer Research and Royal Marsden Hospital, Downs Road, London SM2 5PT, UK.
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Continual reassessment method for dose escalation clinical trials in oncology: a comparison of prior skeleton approaches using AZD3514 data. BMC Cancer 2016; 16:703. [PMID: 27581751 PMCID: PMC5007718 DOI: 10.1186/s12885-016-2702-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Accepted: 08/10/2016] [Indexed: 11/10/2022] Open
Abstract
Background The continual reassessment method (CRM) requires an underlying model of the dose-toxicity relationship (“prior skeleton”) and there is limited guidance of what this should be when little is known about this association. In this manuscript the impact of applying the CRM with different prior skeleton approaches and the 3 + 3 method are compared in terms of ability to determine the true maximum tolerated dose (MTD) and number of patients allocated to sub-optimal and toxic doses. Methods Post-hoc dose-escalation analyses on real-life clinical trial data on an early oncology compound (AZD3514), using the 3 + 3 method and CRM using six different prior skeleton approaches. Results All methods correctly identified the true MTD. The 3 + 3 method allocated six patients to both sub-optimal and toxic doses. All CRM approaches allocated four patients to sub-optimal doses. No patients were allocated to toxic doses from sigmoidal, two from conservative and five from other approaches. Conclusions Prior skeletons for the CRM for phase 1 clinical trials are proposed in this manuscript and applied to a real clinical trial dataset. Highly accurate initial skeleton estimates may not be essential to determine the true MTD, and, as expected, all CRM methods out-performed the 3 + 3 method. There were differences in performance between skeletons. The choice of skeleton should depend on whether minimizing the number of patients allocated to suboptimal or toxic doses is more important. Trial registration NCT01162395, Trial date of first registration: July 13, 2010. Electronic supplementary material The online version of this article (doi:10.1186/s12885-016-2702-6) contains supplementary material, which is available to authorized users.
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Dose-Seeking Phase I Trials for Currently Approved Molecular-Targeted Therapies in the USA: The Dose-Limiting Toxicity Definition Issue. Pharmaceut Med 2016. [DOI: 10.1007/s40290-016-0138-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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van Brummelen EMJ, Huitema ADR, van Werkhoven E, Beijnen JH, Schellens JHM. The performance of model-based versus rule-based phase I clinical trials in oncology : A quantitative comparison of the performance of model-based versus rule-based phase I trials with molecularly targeted anticancer drugs over the last 2 years. J Pharmacokinet Pharmacodyn 2016; 43:235-42. [PMID: 26960536 DOI: 10.1007/s10928-016-9466-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Accepted: 02/17/2016] [Indexed: 01/17/2023]
Abstract
Phase I studies with anticancer drugs are used to evaluate safety and tolerability and to choose a recommended phase II dose (RP2D). Traditionally, phase I trial designs are rule-based, but for several years there is a trend towards model-based designs. Simulations have shown that model-based designs perform better, faster and are safer to establish the RP2D than rule-based designs. However, the superiority of model-based designs has never been confirmed based on true trial performance in practice. To aid evidence-based decisions for designing phase I trials, we compared publications of model-based and rule-based phase I trials in oncology. We reviewed 172 trials that have been published in the last 2 years and assessed the following operating characteristics: efficiency (trial duration, population size, dose-levels), patient safety (dose-limiting toxicities (DLTs)) and treatment optimality (percentage of patients treated below and at or above the recommended phase 2 dose). Our results showed a non-significant but clinically relevant difference in trial duration. Model-based trials needed 10 months less than rule-based trials (26 versus 36 months; p = 0.25). Additionally, fewer patients were treated at dose-levels below the RP2D (31 % versus 40 %; p = 0.73) while safety was preserved (13 % DLTs versus 14 % DLTs). In this review, we provide evidence to encourage the use of model-based designs for future phase I studies, based on a median of 10 months of time gain, acceptable toxicity rates and minimization of suboptimal treatment.
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Affiliation(s)
- E M J van Brummelen
- Department of Clinical Pharmacology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX, Amsterdam, The Netherlands
| | - A D R Huitema
- Department of Pharmacy, The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - E van Werkhoven
- Department of Biometrics, The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - J H Beijnen
- Department of Pharmacy, The Netherlands Cancer Institute, Amsterdam, The Netherlands.,Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, The Netherlands
| | - J H M Schellens
- Department of Clinical Pharmacology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX, Amsterdam, The Netherlands. .,Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, The Netherlands.
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Petroni GR, Wages NA, Paux G, Dubois F. Implementation of adaptive methods in early-phase clinical trials. Stat Med 2016; 36:215-224. [PMID: 26928191 DOI: 10.1002/sim.6910] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Revised: 12/15/2015] [Accepted: 01/27/2016] [Indexed: 12/29/2022]
Abstract
There has been constant development of novel statistical methods in the design of early-phase clinical trials since the introduction of model-based designs, yet the traditional or modified 3+3 algorithmic design remains the most widely used approach in dose-finding studies. Research has shown the limitations of this traditional design compared with more innovative approaches yet the use of these model-based designs remains infrequent. This can be attributed to several causes including a poor understanding from clinicians and reviewers into how the designs work, and how best to evaluate the appropriateness of a proposed design. These barriers are likely to be enhanced in the coming years as the recent paradigm of drug development involves a shift to more complex dose-finding problems. This article reviews relevant information that should be included in clinical trial protocols to aid in the acceptance and approval of novel methods. We provide practical guidance for implementing these efficient designs with the aim of augmenting a broader transition from algorithmic to adaptive model-guided designs. In addition we highlight issues to consider in the actual implementation of a trial once approval is obtained. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- Gina R Petroni
- Division of Translational Research and Applied Statistics, Department of Public Health Sciences, The University of Virginia, Charlottesville, VA, 22908, U.S.A
| | - Nolan A Wages
- Division of Translational Research and Applied Statistics, Department of Public Health Sciences, The University of Virginia, Charlottesville, VA, 22908, U.S.A
| | - Gautier Paux
- Oncology Clinical Biostatistics, Institut de Recherches Internationales Servier (IRIS), Suresnes Cedex, 92284, France
| | - Frédéric Dubois
- Oncology Clinical Biostatistics, Institut de Recherches Internationales Servier (IRIS), Suresnes Cedex, 92284, France
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Abstract
Abstract
The past 70 years have seen childhood acute lymphoblastic leukemia move from a fatal disease with a survival of barely 4 months to a curable disease in >85% of patients. It has become clear that as treatment has intensified, more children are cured but at the expense of increased toxicity which for some can cause significant long-term morbidity and even mortality. The drive in more recent years has been to identify sensitive markers of disease and response to treatment to allow a reduction in therapy in those who do not require it and more intensive treatment in those who do. Clinical characteristics have been used to stratify patients into different risk groups and this, coupled with following response at a molecular level, has done much to tailor treatment to the patient. Considerable research has been focused on the molecular characteristics of the leukemia itself to elucidate the biologic mechanisms underlying both the disease and the comparative or absolute resistance of some types of leukemia. These molecular markers can also act as targets for novel therapies, which require newer trial methodologies to prove their utility. There has been less focus on the biology of the patient but it is clear that some patients are more susceptible to adverse events and toxicities than others. Through the use of pharmacogenomics, modification to therapy may be appropriate in certain patients based on their genetic profile. As novel therapies become available, suitable controlled trials in children are essential for their safe use in this population and will ensure that children are not denied timely access to advances in treatment.
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Cotterill A, Lorand D, Wang J, Jaki T. A practical design for a dual-agent dose-escalation trial that incorporates pharmacokinetic data. Stat Med 2015; 34:2138-64. [PMID: 25809576 DOI: 10.1002/sim.6482] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Revised: 03/01/2015] [Accepted: 03/03/2015] [Indexed: 01/01/2023]
Abstract
Traditionally, model-based dose-escalation trial designs recommend a dose for escalation based on an assumed dose-toxicity relationship. Pharmacokinetic data are often available but are currently only utilised by clinical teams in a subjective manner to aid decision making if the dose-toxicity model recommendation is felt to be too high. Formal incorporation of pharmacokinetic data in dose-escalation could therefore make the decision process more efficient and lead to an increase in the precision of the resulting recommended dose, as well as decreasing the subjectivity of its use. Such an approach is investigated in the dual-agent setting using a Bayesian design, where historical single-agent data are available to advise the use of pharmacokinetic data in the dual-agent setting. The dose-toxicity and dose-exposure relationships are modelled independently and the outputs combined in the escalation rules. Implementation of stopping rules highlight the practicality of the design. This is demonstrated through an example which is evaluated using simulation.
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Affiliation(s)
- Amy Cotterill
- Medical and Pharmaceutical Statistics Research Unit, Department of Mathematics and Statistics, Lancaster University, Lancaster, U.K
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Wages NA, Slingluff CL, Petroni GR. A Phase I/II adaptive design to determine the optimal treatment regimen from a set of combination immunotherapies in high-risk melanoma. Contemp Clin Trials 2015; 41:172-9. [PMID: 25638752 DOI: 10.1016/j.cct.2015.01.016] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Revised: 01/22/2015] [Accepted: 01/23/2015] [Indexed: 12/22/2022]
Abstract
In oncology, vaccine-based immunotherapy often investigates regimens that demonstrate minimal toxicity overall and higher doses may not correlate with greater immune response. Rather than determining the maximum tolerated dose, the goal of the study becomes locating the optimal biological dose, which is defined as a safe dose demonstrating the greatest immunogenicity, based on some predefined measure of immune response. Incorporation of adjuvants, new or optimized peptide vaccines, and combining vaccines with immune modulators may enhance immune response, with the aim of improving clinical response. Innovative dose escalation strategies are needed to establish the safety and immunogenicity of new immunologic combinations. We describe the implementation of an adaptive design for identifying the optimal treatment strategy in a multi-site, FDA-approved, phase I/II trial of a novel vaccination approach using long-peptides plus TLR agonists for resected stage IIB-IV melanoma. Operating characteristics of the design are demonstrated under various possible true scenarios via simulation studies. Overall performance indicates that the design is a practical Phase I/II adaptive method for use with combined immunotherapy agents. The simulation results demonstrate the method's ability to effectively recommend optimal regimens in a high percentage of trials with manageable sample sizes. The numerical results presented in this work include the type of simulation information that aid review boards in understanding design performance, such as average sample size and frequency of early trial termination, which we hope will augment early-phase trial design in cancer immunotherapy.
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Affiliation(s)
- Nolan A Wages
- Division of Translational Research & Applied Statistics, Department of Public Health Sciences University of Virginia, Charlottesville, VA 22908, USA.
| | - Craig L Slingluff
- Division of Surgical Oncology, Department of Surgery, University of Virginia, Charlottesville, VA 22904-4135, USA
| | - Gina R Petroni
- Division of Translational Research & Applied Statistics, Department of Public Health Sciences University of Virginia, Charlottesville, VA 22908, USA
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Iasonos A, O'Quigley J. Adaptive dose-finding studies: a review of model-guided phase I clinical trials. J Clin Oncol 2014; 32:2505-11. [PMID: 24982451 DOI: 10.1200/jco.2013.54.6051] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
PURPOSE We provide a comprehensive review of adaptive phase I clinical trials in oncology that used a statistical model to guide dose escalation to identify the maximum-tolerated dose (MTD). We describe the clinical setting, practical implications, and safety of such applications, with the aim of understanding how these designs work in practice. METHODS We identified 53 phase I trials published between January 2003 and September 2013 that used the continual reassessment method (CRM), CRM using escalation with overdose control, or time-to-event CRM for late-onset toxicities. Study characteristics, design parameters, dose-limiting toxicity (DLT) definition, DLT rate, patient-dose allocation, overdose, underdose, sample size, and trial duration were abstracted from each study. In addition, we examined all studies in terms of safety, and we outlined the reasons why escalations occur and under what circumstances. RESULTS On average, trials accrued 25 to 35 patients over a 2-year period and tested five dose levels. The average DLT rate was 18%, which is lower than in previous reports, whereas all levels above the MTD had an average DLT rate of 36%. On average, 39% of patients were treated at the MTD, and 74% were treated at either the MTD or an adjacent level (one level above or below). CONCLUSION This review of completed phase I studies confirms the safety and generalizability of model-guided, adaptive dose-escalation designs, and it provides an approach for using, interpreting, and understanding such designs to guide dose escalation in phase I trials.
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Affiliation(s)
- Alexia Iasonos
- Alexia Iasonos, Memorial Sloan Kettering Cancer Center, New York, NY; and John O'Quigley, Université Paris VI, Paris, France.
| | - John O'Quigley
- Alexia Iasonos, Memorial Sloan Kettering Cancer Center, New York, NY; and John O'Quigley, Université Paris VI, Paris, France
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