The eCTD summit

As I discussed in my previous post, FDA issued version 1.5.1 of Study Data Specifications in January of 2010.  Although the changes in the new version were not great, they were significant for eCTD as a new specification for organizing datasets was defined.   The change has to do with how the files are organized in the file structure in which an eCTD is delivered to indicate whether they were STDM or legacy format.  However, the change had no effect on the Table of Contents that is visible to a reviewer (created from the eCTD XML backbone).  In a recent development, ICH M2 working group has defined an update to the valid values list for study tagging files to introduce file tags that would allow a review tool to identify dataset types when displaying the eCTD Table of Contents.

The new specifications for organizing study datasets and their associated files in folders are summarized in the following figure.  In the document, an accompanying table provides further definition of the folders.

  New Dataset Folder Organization

Compare this with the folder structure required in the previous specification: 

Previous Dataset Folder Organization

You will see an important difference: tabulations must be assigned to a folder based on whether they are STDM datasets or legacy format.  A second difference is that there is now a separate folder for datasets under analysis, where previously analysis datasets were placed directly in the analysis folder.

At the recent ICH meeting in Estonia, the valid-values.xml that defines file tags used to identify the documents in studies was amended to better support the different types of data:

• The existing file tag of data-tabulation-dataset was replaced with data-tabulation-dataset-legacy, data-tabulation-dataset-sdtm, and data-tabulation-dataset-send.
• The existing file tag of analysis-dataset was replaced with analysis-dataset-adam and analysis-dataset-legacy

Look for the new valid-values.xml on the ICH websites in a zip file.  You should talk with your publishing vendor to find out how and when they will support the updated specification.

One final note – the FDA recently retired their own version of the valid-values.xml and reverted to the ICH version.  That means that they restored the file tag of nonclinical-data.  However, the preferred file tag for a nonclinical study is pre-clinical-study-report.