The paper focuses on the importance of reversible interactions to potency and mechanisms of drug resistance. It discusses the systematic assessment of non-covalent binding and chemical reactivity components to the ultimate clinical potency of emerging covalent kinase drugs. The authors deconvolute contributions from the 'reversible' component of a covalent drug, and the assay readout is considered. The study evaluates the kinetic analysis of covalent inhibition of EGFR- L858R/T790M, a disease-relevant double mutant. The data shows the kinetic analysis of various inhibitors and their impact on EGFR mutants.