The oral calcineurin inhibitor voclosporin (ISA-247), currently in phase III development for psoriasis, was investigated in a pharmacokinetic and pharmacodynamic study to develop an optimized dosing strategy. The study was part of a larger, randomized, double-blind, multicenter trial. The following parameters were determined in 138 patients: Psoriasis Area and Severity Index (PASI) 75 at 12 weeks, voclosporin concentration and 2-h post-dose calcineurin activity. At week 12, calcineurin inhibition strongly correlated with PASI 75. When patients achieving a PASI 75 were stratified at 4 weeks depending on calcineurin inhibition above or below 45%, calcineurin inhibition of 45% or greater was associated with the achievement of PASI 75 by week 12, while calcineurin inhibition ...