Expert review of the mutagenicity of carbamates - using (Q)SAR predictions for ICH M7 classification

Presented by Rachel Hemingway at the 2017 SOT Annual Meeting.

The ICH M7 guidelines aim to assess and control mutagenic impurities in pharmaceuticals. These guidelines allow the use of two complementary in silico systems (one expert rule-based and one statistical-based) to predict the bacterial mutagenicity of a given impurity. Assessment of the combination of results produced from two in silico predictions has received a lot of attention, a situation which is complicated when also considering confidence and domain of applicability. The need for additional levels of scrutiny for negatively predicted compounds in certain chemical classes has been suggested in the literature. Carbamates have been highlighted as a chemical class of concern for mutagenicity; but they are versatile and well used, particularly as protecting groups. Derek Nexus contains an in vitro mutagenicity alert for vinyl carbamates based on data and mechanistic knowledge harvested over 30 years.