In a pharmacokinetic substudy of the randomized ASSET trial , 46 de novo kidney transplant patients receiving very low ( 1.5-3 ng/mL ) or low ( 4-7 ng/mL ) tacrolimus exposure after month 3 , both with everolimus and steroids , provided area under the curve ( AUC ) concentration profiles at day 5 and months 1 , 3 , and 12 .