Which requirement ensures that a trial's conduct aligns with approved procedures?

• A. The trial must be conducted in accordance with the protocol that has received prior IRB approval or favorable opinion.
• B. The protocol can be modified freely without approval if investigators agree.
• C. IRB approval is optional if the sponsor consents.
• D. Adherence to the protocol is not necessary if participant safety seems adequate.

Answer: (A)

The main idea is that a trial must be run exactly according to the protocol that has received IRB approval. The protocol sets the plan for what will be done, how participants are selected, what procedures are performed, how data are collected, and how safety is monitored. Following this approved protocol ensures consistency, participant protection, and reliable data. Changes to the protocol typically require IRB review and approval before they are put into practice, and a sponsor’s consent cannot substitute for that oversight. Deviating from the approved plan without proper approval jeopardizes participant safety and the integrity of the study.