4.5.2 states about deviations without agreement

• A. Deviations require only sponsor approval.
• B. Deviations may be implemented freely.
• C. Deviations must always be reported after study completion.
• D. The investigator should not implement any deviation from the protocol without sponsor agreement and prior review and documented approval/favorable opinion from IRB/IEC, except to eliminate an immediate hazard or for logistical/administrative changes.

Answer: (D)

A clinical trial must guard participant safety and maintain data integrity, so any departure from the approved protocol typically can’t be made without proper oversight. The investigator is required to obtain sponsor agreement and prior review and a documented approval or favorable opinion from the IRB/IEC before implementing a deviation. The only exceptions are when immediate hazard to a participant must be addressed right away, or for certain administrative or logistical changes that don’t affect safety or data integrity. This framework ensures that changes are reviewed and approved before they happen, rather than being applied informally.

The other ideas miss essential safeguards: deviations aren’t free to implement on a whim, they aren’t something you can wait to report until the study ends, and you don’t have to ignore protocol rules altogether.