In a 12-month open-label pilot study , 30 adult patients with ADPKD were randomly assigned to low-dose ( LD ) rapamycin ( rapamycin trough blood level , 2-5 ng/ml ) ( LD group , n = 10 ) , standard-dose ( STD ) rapamycin trough level ( > 5-8 ng/ml ) ( STD group , n = 10 ) , or standard care ( SC group , n = 10 ) .