Comparative safety assessment of genetically modified crops: focus on equivalence with reference varieties could contribute to more efficient and effective field trials

The initial compositional analysis of plants plays an important role within the internationally harmonized comparative safety assessment approach for genetically modified plants. Current EFSA guidance prescribes two types of comparison, namely difference tests with regard to a conventional comparator or control, and equivalence tests with regard to a collection of commercial reference varieties. The experience gained so far shows that most of the statistically significant differences between the test and control can be discounted based on the fact that they are still within equivalence limits of reference varieties with a presumed history of safe use. Inclusion of a test variety and reference varieties into field trial design, and of the statistical equivalence test would already suffice for the purpose of finding relevant parameters that warrant further assessment, hence both the inclusion of a conventional counterpart and the performance of difference testing can be omitted. This would also allow for the inclusion of safety testing regimes into plant variety testing VCU (value for cultivation and use) or other, independent variety trials.

Automated summary

The initial compositional analysis of plants is crucial in the internationally harmonized approach to assess the safety of genetically modified plants. The current EFSA guidance suggests two types of comparison methods: difference tests with a conventional comparator or control, and equivalence tests with a collection of commercial reference varieties. Previous experience shows that statistically significant differences between the test and control can often be ignored if they fall within the equivalence limits of reference varieties with a presumed safe history. Thus, the inclusion of a conventional counterpart and the performance of difference testing can be omitted in favor of including safety testing regimes into other variety trials.