Gerding DN, et al. - Researchers conducted the IMPACT 1 and IMPACT 2 trials—identically designed, multicenter, double-blind, placebo-controlled, non-inferiority, randomized, phase 3 studies—to compare the safety and efficacy of cadazolid with vancomycin in patients with Clostridium difficile infection. They performed IMPACT 1 in Australia, Brazil, Canada, France, Germany, Italy, the Netherlands, Peru, Poland, Romania, Spain, and the United States; IMPACT 2 was performed in Argentina, Belgium, Brazil, Canada, Chile, Croatia, Czech Republic, Greece, Hungary, Israel, Romania, Slovakia, South Korea, the United Kingdom, and the United States. Patients were randomized to receive either oral cadazolid 250 mg twice daily with vancomycin-matching placebo capsule four times daily or oral vancomycin 125 mg four times a day with cadazolid-matching placebo suspension twice daily for 10 days, with 30 days of follow-up. According to findings, cadazolid was safe and well tolerated but was not identified to be non-inferior to vancomycin for clinical cure in one of two phase 3 C. difficile infection trials.