In accordance with ICH, which of the following is an acceptable protocol review frequency for an IRB?

The International Council for Harmonisation (ICH) Guideline for Good Clinical Practice (GCP) E6(R2) mandates the minimum frequency for the continuing review of ongoing clinical trials by an Institutional Review Board (IRB) or Independent Ethics Committee (IEC). Section 3.1.4 specifies that the IRB/IEC must review ongoing trials at intervals appropriate to the level of risk, but at least once per year. This "at least annually" requirement establishes a 12-month interval as the standard maximum period between reviews to ensure the continued protection of human subjects' rights, safety, and well-being.

A. 6 months: While more frequent reviews are permissible and may be appropriate for high-risk studies, 12 months is the standard minimum frequency (maximum interval) explicitly required by ICH GCP.

C. 24 months: This interval exceeds the "at least once per year" mandate and is therefore non-compliant with ICH GCP guidelines for continuing review.

D. 36 months: This interval significantly exceeds the maximum allowable period of one year between reviews and is a clear violation of ICH GCP standards.

1. International Council for Harmonisation (ICH). (2016). Integrated Addendum to ICH E6(R1): Guideline for Good Clinical Practice E6(R2). Section 3.1.4, page 12. "The IRB/IEC should conduct continuing review of each ongoing trial at intervals appropriate to the degree of risk to human subjects, but at least once per year."

2. U.S. Food and Drug Administration (FDA). (2023). Code of Federal Regulations, Title 21, Part 56, Section 109 (21 CFR 56.109(f)). "An IRB shall conduct continuing review of research covered by these regulations at intervals appropriate to the degree of risk, but not less than once per year."

3. University of California, San Francisco (UCSF), Human Research Protection Program. IRB Continuing Review Guidance. "Federal regulations require that the IRB re-approve all non-exempt human research projects at least annually (unless the study qualifies for an exception)." This university guidance reflects the implementation of federal and international standards.