Fig 1. Illustration of the pass/fail criteria for binding kinetics of histidine substitution variants relative to the reference antibody (mAb 1).

Kinetics were assessed by measuring the difference in phase shift via biolayer interferometry for association with C5 at pH 7.4 and dissociation of the complex at pH 7.4 and pH 6.0. Accepted differences in phase shift were: (A) a maximum reduction of 33% of the peak phase shift at 800 seconds for association at pH 7.4; (B) a maximum reduction of no more than three-fold of the peak phase shift at 800 seconds during dissociation at pH 7.4; (C) a minimum reduction of at least three-fold of the peak phase shift at 800 seconds for dissociation at pH 6.0.