Canakinumab groups were categorised as low ( 0.03 mg/kg i.v. once ; N = 20 ) , intermediate ( 0.1 and 0.3 mg/kg i.v. once , 5 and 15 mg s.c. monthly ; N = 247 ) , medium ( 1.5 mg/kg i.v. once , 50 mg s.c. monthly and 150 mg s.c. once ; N = 268 ) , and high doses ( 10 mg/kg i.v. once and 150 mg s.c. monthly ; N = 137 ) and compared with placebo ( N = 354 ) .