In this phase @ , double-blind , placebo-controlled study undertaken at @ centres in Asia , Australia , Canada , Europe , and the USA , adults ( aged @ years old ) with active psoriatic arthritis were randomly allocated in a @:@:@:@ ratio with computer-generated blocks to receive subcutaneous placebo or secukinumab @ mg , @ mg , or @ mg once a week from baseline and then every @ weeks from week @ .