The investigators assessed whether the drug reduced the severity of psoriasis symptoms compared to the placebo and evaluated safety by monitoring adverse events. By the 12th week, 76.4 to 81.8 percent of patients has their psoriasis classified as "clear" or "minimal" compared to 3.2% of patients on the placebo. By the 60th week, 68.7 to 78.3 percent of patients had maintained their improvement.