What type of information must not be duplicated when referencing another IND?

The correct choice regarding the type of information that must not be duplicated when referencing another Investigational New Drug (IND) is chemistry, manufacturing, and controls (CMC) information. CMC details are critical in ensuring the quality and consistency of the drug product. This information encompasses how the drug is produced, including the chemistry involved in its formulation and the manufacturing processes, which are highly regulated.

When a new IND references an existing IND, it's essential that the CMC information remains distinct and not duplicated because each IND must meet specific regulatory standards and ensure that quality control and validation processes are followed for the new formulation. Duplicating CMC information could lead to inconsistencies and safety concerns, making it critical that this information is unique to each application.

In contrast, patient demographics, randomization methods, and protocol designs may have some flexibility or commonalities when referencing existing INDs, as these aspects can often be adapted or tailored to suit the specifics of the new study while maintaining compliance with regulatory requirements. However, CMC details must be specific and appropriately documented for each IND to uphold stringent quality and safety regulations.