Choosing between a full, abbreviated, synopsis or interim report
How fully a study is reported depends on what it contributes to the evaluation of a product. A study can be reported in full, in an abbreviated report, in a synopsis or, while the trial is still running, in an interim report, and an abbreviated or synopsis report still carries the study's safety data.
The kinds of report
Different types of clinical study report can be prepared, depending on the context and purpose of the trial and on the requirements of the regulatory authority reviewing the data.
The full report is the most comprehensive type: it includes all the data and analyses from the trial, and it is typically used for regulatory purposes, such as submitting data to the FDA in support of a new drug application.
An abbreviated report is used for studies that do not contribute to the evaluation of efficacy or provide definitive information on the clinical pharmacology of the investigational product.
A synopsis report is generally prepared for studies that are not relevant to evaluating the effectiveness and clinical pharmacology of the medicinal product but provide data for evaluating its safety. Examples are studies of routes of administration for which marketing approval is not required, incomplete studies that enrolled fewer than one-third of the intended participants, and early general phase 1 safety-tolerance studies.
An interim report is used to report on the progress of a trial that is still ongoing. It is typically shorter than a full report, is written once the primary and secondary endpoints are met, and may be used for a marketing authorisation application before the trial is complete. Data on the exploratory endpoints and on long-term follow-up are included later in the full report.
The guidance on the formats
ICH E6 points out that, under ICH E3, abbreviated reports may be acceptable in certain cases. In 2007, a study conducted during a product's development that ultimately did not contribute to the evaluation of its effectiveness for a specific indication had to be submitted to the regulatory authorities as an abbreviated report. ICH E3, however, covered only the structure and content of full reports, and a guideline the FDA issued in 1999 was the only document from a regulatory authority that recommended which sections an abbreviated report can include.
In the absence of EU-specific guidance, the consensus in 2014, supported by Alfaro and colleagues in 2007, was to follow the FDA's 1999 guidance. For a complete understanding of the abbreviated and synopsis formats, a writer is referred to two documents: the FDA's 1999 guidance, which covers when full study reports, abbreviated reports and synopses can be used to submit data on the effectiveness of new drugs and biological products, and the 2007 article by Alfaro and colleagues, which describes which sections have to be included in abbreviated reports written during the clinical development of new medicinal products for human use.
When a shorter report is acceptable
Under ICH E3, depending on the regulatory authority's review policy, abbreviated reports that use summarised data or omit some sections may be acceptable for uncontrolled studies or other studies not designed to establish efficacy, for seriously flawed or aborted studies, and for controlled studies that examine conditions clearly unrelated to those for which a claim is made. A controlled safety study, however, should be reported in full. For kinds of trial other than efficacy and safety trials, such as clinical pharmacology studies, a less detailed report might be appropriate, depending on the nature and importance of the study. Where there is any question about whether the reports are needed, it may be useful to consult the regulatory authority.
Under the FDA's guidance, studies conducted during a product's development that ultimately do not contribute to the evaluation of its effectiveness for a specific indication should be submitted as either abbreviated reports or synopses. In essence, key pivotal efficacy studies should be fully reported. One author of a guide to medical writing adds that many important studies that are crucial to internal decision-making contribute little to regulatory claims, and that these can be reported in abbreviated form. For example, three formulations might be evaluated to select one suitable for phase III pivotal studies and eventual marketing, and once the data are available and the selection is made, writing a full report is a waste of time. Writing abbreviated reports to avoid unnecessary full reports can save much time.
Under the FDA's 1999 guidance, the studies for which synopsis reports are acceptable are generally those conducted only in enough depth to assess whether they cast doubt on a product's safety, and are often studies for which marketing approval is not being sought.
What a shorter report still carries
Regulatory decisions on marketing approval are made on the evaluation of both efficacy and safety. An abbreviated report should always include all safety data. Under ICH E3, an abbreviated report should likewise include a full description of safety aspects, and enough detail of design and results to allow the regulatory authority to determine whether a full report is needed.
An abbreviated report contains abbreviated methods and efficacy sections and a detailed safety section. Following the FDA's 1999 guidance, as the consensus in the EU did in 2014, an abbreviated report should report selected front-end material, subject disposition information and, crucially, the safety data in full. Selected appendices are required, adapting the US list by omitting the US archival listings.
A synopsis report may follow the ICH E3 synopsis format with a supplemental safety discussion, or may substitute published literature for the synopsis and discussion. The protocol and its amendments are appended to it.