A practical guide for the assay-dependent characterisation of irreversible inhibitors.

Irreversible targeted covalent inhibitors, in the past regarded as inappropriately reactive and toxic, have seen a recent resurgence in clinical interest. This paradigm shift is attributed to the exploitation of the two-step mechanism, in which a high affinity and selectivity (, low ) scaffold binds the target and only then does a pendant low intrinsic reactivity warhead react with the target (moderate ). This highlights the importance of evaluating inhibitors by deriving both their and values.