Colchicine 0.5 mg capsule orally once daily throughout the whole treatment phase of 16 weeks plus placebo matching canakinumab s.c. at Days 1, 29, 57, and 85. Allopurinol treatment was initiated at the latest at baseline (Visit 2) according to the patient's renal function / estimated creatinine clearance at screening (Visit 1). Allopurinol was administered orally to all randomized patients once daily (100 mg- 300 mg) for 24 weeks.