Considerations for Medical Writers Developing Clinical Trial Protocols
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Clinical trial design: Considerations for medical writers developing clinical trial protocols Tiago Silva have been made to harmonise the structure of not available. This creates an additional challenge IQVIA, Porto Salvo, Portugal trial protocols (e.g., TransCelerate Common for writers. Protocol Template 2 and SPIRIT Statement 3), a This article reviews the main concepts standard similar to ICH E3 4 for trial reports, affecting trial designs presented in proto cols and Correspondence to: defining what information to present and how is how to address them from a medical writing Tiago Silva Sr Medical Writer Global Medical Writing Table 1. Protocol writing tips and considerations for key sections IQVIA Lagoas Park Introduction Edifício 3 – Piso 3 l The introduction section should include a literature review covering the indication, 2740-266 Porto Salvo available therapeutic options, and test treatment(s) Portugal l Present the scientific rationale of the trial, identifying its primary purpose, what it aims to +351 219016549 achieve, and its importance [email protected] Objectives l Confirm consistency between the rationale and objectives Abstract l Write SMART objectives (see Table 2 opposite) Clinical trial protocols must provide a clear trial design to meet the study objectives. Population Medical writers must understand and be l Define the target population and present a list of inclusion/exclusion criteria ready to review and discuss aspects of the trial l Confirm that the inclusion/exclusion criteria are consistent with the objectives design with the protocol development team, in order to write a clear and accurate protocol. Endpoints This article reviews some of the main trial l Write short descriptions of the endpoints, which should be measurable design concepts medical writers should l Confirm consistency between the objectives and endpoints expect to find when writing protocols. l Confirm that all variables are captured in the schedule of assessments l Confirm consistency between the defined estimands, objectives, endpoints, and analyses Introduction Trial design Clinical trial protocols for trials evaluating l Confirm that the trial design is clear and consistent with the objectives, endpoints, and schedule pharmacological products are complex docu - of assessments ments that describe the medical, ethical, and l Confirm that bias minimisation methods are presented. If randomisation and/or blinding are regulatory foundations of the trial. Medical not used in a comparative trial, this should be justified writers work together with protocol development teams of subject matter experts (including Control groups medical experts, statisticians, regulatory experts, l Confirm that the control group is clearly identified and justified operational experts, and pharmacokineticists) to l Confirm that the control group is aligned with the design and objectives write clear protocols that will address the l Confirm that all test treatments (including placebo) are clearly identified and characterised proposed medical questions and protect partici - pant safety and rights. To accomplish this, writers Statistical considerations must understand and be able to communicate l Confirm consistency between statistical considerations and trial endpoints clinical trial design concepts that are often l Confirm that all variables analysed are collected at the appropriate times in the schedule of complex. Moreover, although International assessments Council for Harmonisation (ICH) Good Clinical l Avoid too much detail when presenting the statistical analysis methods, referring to the Practice (GCP) 1 provides recommendations on statistical analysis plan when appropriate what a trial protocol should include, and efforts 56 | March 2020 Medical Writing | Volume 29 Number 1 Silva – Clinical trial design perspec tive while ensuring compliance with ICH Objectives in clinical trials can be divided into Population GCP. Operational, regulatory, and ethical three categories: 7 Protocols should briefly define the target concepts are not discussed. l Primary (typically one): aims to directly population (i.e., the set of people throughout the Table 1 summarises some writing tips for each answer the primary purpose of the clinical world for which the trial results may be key section of the protocol. trial generalised). 8 A detailed list of inclusion and l Secondary : other actions relevant to and/or exclusion criteria should follow, specifying: 8,9 Rationale indirectly associated with the rationale l Demographic characteristics (e.g., age, sex, Clinical trials assess the efficacy, safety, and/or l Exploratory : hypothesis-generating objec - body mass index) pharmacological characteristics of medicinal tives that can be confirmed in dedicated studies l The medical indication under study, products in human participants. The protocol must present a rationale that identifies the primary purpose of the trial, usually in the Table 2. Example of a SMART written objective “Introduction” section (Table 1). At trial con - ception, the protocol development team should To assess the efficacy of paracetamol 1000 mg per os versus placebo in adult patients with fever of consider: unknown origin (body temperature >37.5°C) 2 hours after administration. l If the rationale is clear l If the trial is clinically relevant and feasible Specific: identifies the action (to assess efficacy), medication(s) (paracetamol and placebo), l If an unnecessary risk/burden will be posed population (adults), and indication (fever of unknown origin) to trial participants Measurable: temperature is a measurable variable Objectives Achievable: feasible and not burdensome to the participant (to be confirmed by the trial medical Trial objectives are the actions proposed to fulfil expert) the trial’s rationale. The objectives should be Relevant: objectives should be clinically relevant (to be confirmed by the trial medical expert) conceived by the protocol development team and written by the medical writer according to the Time based: in this example, a 2 hour timeframe is specified SMART principles (Table 2). 5,6 www.emwa.org Volume 29 Number 1 | Medical Writing March 2020 | 57 Clinical trial design – Silva acceptable/prohibited comorbidities, and l Mean body temperature 2 hours after test acceptable/prohibited concomitant medi - treatment administration cations l Ethical requirements for participation (e.g., The protocol development team is responsi ble informed consent) for defining the endpoints, while the medical l Exclusion criteria that may bias result writer should ensure that they are clearly written interpretation or pose an unnecessary risk to (Table 1). the participant Endpoints are classified in accordance with the corresponding objectives (primary, sec - Endpoints ondary, exploratory). The primary endpoint In clinical trials, variables are the parameters should provide the most clinically relevant and (sociodemographic, clinical efficacy and safety, convincing evidence directly related to the laboratory/imaging-related, etc.) that will be primary objective of the trial and its selection measured. Variables can be independent (vari - should reflect the accepted norms and standards ables that potentially influence health outcomes, in the relevant field of research. 11 e.g., treatment, age, sex, smoking history) or Endpoints should be measurable and should dependent (health outcomes, e.g., vital signs, be concisely described in the protocol, while laboratory parameters). 8 details of how the endpoints will be An endpoint is defined by The captured can be provided in one or Spilker as “ an indicator meas ured protocol defines more dedicated protocol l Population-level summary statis tics for in a patient or biological sample the procedures by which sections. All endpoints and the endpoint: the basis for treatment to assess safety, efficacy or a clinical trial is conducted, variables must also be comparisons another trial objective .10 Each captured in a schedule of A summary of the use of estimands in clinical objective must be matched and its writing requires careful assessments that identifies trials can be found in a publication by Bridge and with at least one endpoint, assessment of all concepts which variables will be Schindler. 13 to ensure that the right surrounding trial design for measured at each trial visit variables will be captured and accuracy and and that provides sum marised Trial design that all questions posed by the procedural information for The trial design will dictate participant treatment trial will be addressed. As an consistency. quick reference to the trial site and follow-up, the number of treatment groups, example, let’s consider the following teams. and data collection, among other aspects. objective: Estimands were recently introduced in l To assess the efficacy of paracetamol 1,000 mg ICH E9 (R1) and describe the treatment effect Single group design per os versus placebo in adult patients with fever with consideration of specified post- In single group trials, variables are compared in of unknown origin (body temperature >37.5°C) randomisation events and whether the outcome the same participant before and a certain time 2 hours after administration of the test treatment would be under different conditions. 12 Four after exposure to the test treatment (intra - interrelated attributes are considered for this participant analysis). 8 These are typically early Two possibilities for the corresponding endpoint purpose: 12,13 phase trials or are conducted where limited can