In the U.S., how does the FDA treat ICH E6?

The FDA treats ICH E6 as optional guidelines. This reflects the stance that while ICH E6 provides valuable recommendations for good clinical practices in the conduct of clinical trials, adherence to these guidelines is not legally mandated. The guidelines are intended to harmonize regulatory requirements across countries and improve the quality and efficiency of clinical trials, but compliance is not enforced as a part of federal law in the U.S. Instead, organizations conducting clinical research can choose to follow ICH E6 guidelines to ensure that they maintain high standards for ethical and scientific quality, making them beneficial but not compulsory.

Other options suggest a more stringent regulatory framework than what is applicable to ICH E6 in the U.S., and thus do not accurately reflect the FDA's position on these guidelines.