The U.S. Department of Agriculture's (USDA) Animal and Plant Health Inspection Service (APHIS) recently reviewed a hemp plant modified using genetic engineering. Growing Together Research, Inc. modified a hemp plant to reduce tetrahydrocannabinol (THC) and cannabichromene (CBC) levels. They reviewed the modified hemp plant to determine whether it posed an increased plant pest risk as compared to cultivated hemp. 
APHIS found this modified hemp is unlikely to pose an increased plant pest risk compared to other cultivated hemp. As a result, it is not subject to regulation under 7 CFR part 340. "From a plant pest risk perspective, this hemp may be safely grown and bred in the United States."
You can view the RSR request from Growing Together Inc. and APHIS' response letter on the APHIS website. Their response is based on information from the developers and their:
- familiarity with plant varieties;
- knowledge of the traits and;
- understanding of the modifications.
Under 7 CFR part 340, developers may request an RSR when they believe a modified plant is not subject to regulation. APHIS reviews the modified plant and considers whether it might pose an increased plant pest risk compared to a nonregulated plant. "If our review finds a plant is unlikely to pose an increased plant pest risk relative to the comparator plant, APHIS issues a response indicating the plant is not subject to the regulations."
Source: aphis.usda.gov