The safety of AVI-7288 was evaluated in a randomized , multiple-ascending-dose study in which 40 healthy humans ( 8 humans per dose group ) received 14 once-daily infusions of AVI-7288 ( 1 mg , 4 mg , 8 mg , 12 mg , or 16 mg per kilogram of body weight ) or placebo , in a 3:1 ratio .