In this placebo-controlled , double-blind , 36-week , phase 2 trial ( ATAMS ) in Australia , Canada , Europe , and the USA , patients aged 18-60 years with relapsing multiple sclerosis were randomly assigned via an interactive voice response system in a 1:1:1:1 ratio , stratified by geographical region , to receive weekly subcutaneous injections with atacicept ( 25 , 75 , or 150 mg ) or placebo .