Genotoxicity
The potential of a substance to damage DNA, which could lead to mutations and potentially cancer. Genotoxicity testing (including bacterial mutation, chromosomal aberration, and micronucleus assays) is a standard preclinical requirement for peptide drug development.
Technical Context
Standard genotoxicity battery (ICH S2(R1)): Test 1 — bacterial reverse mutation assay (Ames test, detecting point mutations in Salmonella typhimurium and E. coli); Test 2 — in vitro mammalian cell assay (chromosomal aberration in CHO/CHL cells OR mouse lymphoma tk assay, detecting clastogenicity and aneuploidy); Test 3 — in vivo micronucleus test (detecting clastogenicity/aneuploidy in rodent bone marrow or peripheral blood). For biotechnology-derived peptides (recombinant proteins, long peptides), ICH S6(R1) states that genotoxicity testing is generally not needed because: peptides do not interact with DNA directly, they are degraded to amino acids, and standard bacterial assays are not relevant to large molecule mechanisms. However, for synthetic peptides with non-natural components (linkers, chemical modifications, conjugates), standard genotoxicity testing may be warranted.