For Period II • To assess safety and tolerability of four doses of ACZ885 (5 mg, 15 mg, 50 mg, and 150 mg) vs. placebo as an add-on regimen over 4 months. • To assess the effect on HbA1c of four doses of ACZ885 (5 mg, 15 mg, 50 mg, and 150 mg) vs. placebo as an add-on regimen over 4 months. For Period III • To assess the anti-apoptotic effect of ACZ885 vs. placebo on the meal challenge derived dynamic phase secreted insulin per unit of glucose concentration in patients who have been on study drug anywhere from 6 months to 18 months. For Period IV • To assess the safety and tolerability of active treatment of ACZ885 vs. placebo, as an add-on regimen over a minimum of 24 months (up to 48 months) period.