Documents Applicable to Multiple Content Locations in CTD Structure
In some cases, a document in an eCTD application may be applicable in more than one content location in the CTD structure. For example, a single nonclinical pharmacokinetic (PK) study may have evaluated both absorption and distribution of the drug. In the CTD structure, the study report could belong in either Module 4 Section 22.214.171.124 Absorption, or Module 4 Section 126.96.36.199 Distribution. The best practice recommendation is for the sponsor to submit one copy of the report in the application, and provide a reference to the report from the second location to direct the reviewer where to find to the content. For example, the nonclinical PK study report would be provided once in Module 4, Section 188.8.131.52, and a single page “Note to Reviewer” would be provided in Module 4, Section 184.108.40.206. The “Note to Reviewer” should state a brief explanation that the study evaluated both absorption and distribution of the drug and the report is provided in Section 220.127.116.11. Study tagging files should be created in both 18.104.22.168 and 22.214.171.124 for the study, and the “Note to Reviewer” should be tagged as study-report-body. This method of cross-referencing content applicable to more than one location in the CTD structure will clearly point the reviewer to the relevant information in the eCTD application.
This same technique may be used to cross-reference information between two applications. For example, a clinical study may be relevant to more than one eCTD application. Rather than submitting the study documents to each eCTD application, the information may be submitted once, and then referenced in the second application utilizing the “Note to Reviewer” practice. The sponsor should include Module 1.4.4 Cross Reference to Other Applications in the eCTD application. Prior to implementing this practice, it is recommended that the sponsor receive confirmation from the review division. We do not recommend sponsors create hyperlinks from one eCTD application to another. In order for cross-application hyperlinking to work, the applications must reside on the same physical server and the application folder names cannot change. Although cross-application hyperlinks may work at the time of submission, there is no guarantee that the information will continue to reside on the same physical server and retain the same folder naming structure throughout the months and years ahead. To avoid broken links, the “Note to Reviewer” method may be employed to gain the benefits of cross-referencing information from one application to another, while maintaining the technical integrity of the eCTD application over time.