Ceftobiprole medocaril is a cephalosporin antibiotic with anti-MRSA (Methicillin-Resistant Staphylococcus Aureus) activity. Ceftobiprole medocaril is not yet approved for the treatment of complicated skin and skin structure infections. This is a randomized, double-blind, multicenter study of ceftobiprole medocaril plus placebo versus a comparator to assess the effectiveness and safety of ceftobiprole medocaril in patients with complicated skin and skin structure infections. The patients will be randomized to ceftobiprole medocaril plus placebo or a comparator. The primary endpoint is the clinical cure rate of ceftobiprole medocaril at the test-of-cure visit. The patients will receive either ceftobiprole medocaril plus placebo or a comparator for 7 to 14 days (unless extended at discretion of medical monitor).