Efficacy and Safety of Sequential Intravenous/Oral Moxifloxacin vs Intravenous/Oral Amoxicillin/Clavulanate for Complicated Skin and Skin Structure Infections

Background: Complicated skin and skin structure infections (cSSSIs) are an important healthcare concern worldwide, as they can be life-threatening and challenging to treat. cSSSIs are normally managed using a combination of surgical intervention and prompt antibiotic use. New therapeutic options, including novel antibiotics, are required to improve outcomes in terms of duration of illness and to reduce the consumption of healthcare resources. Methods: This was a prospective, randomized, open-label, parallel-group, multinational clinical study comparing sequential intravenous/oral (iv/po) moxifloxacin, 400 mg once daily, and iv amoxicillin/clavulanate, 1,000 mg/200 mg three times daily followed by po amoxicillin/clavulanate, 500 mg/125 mg three times daily, for 7-21 days in hospitalized patients. Results: A total of 804 patients were enrolled (mean age 51.8 years). The most common clinical diagnosis was complicated erysipelas (32.1% moxifloxacin; 30.0% amoxicillin/clavulanate) and major abscess (31.1% moxifloxacin; 29.3% amoxicillin/clavulanate). Overall clinical success rates at the test-of-cure (TOC) visit (14-28 days post-treatment) for the per-protocol population (primary efficacy variable) were 80.6% (254/315) for patients in the moxifloxacin group and 84.5% (268/317) for those receiving amoxicillin/clavulanate (95% confidence interval [CI] -9.41, 2.18). Similar results were obtained for the intention-to-treat population (95% CI -7.56, 4.31). In both treatment groups, the highest clinical success rates were recorded for patients with complicated erysipelas, major abscess, surgical wound infection, and cellulitis. The lowest clinical cure rates were reported for diabetic foot infection and necrotizing fasciitis. In the microbiologically evaluable population, the bacteriological success rate (eradication and presumed eradication) was 76.0% (127/167) in the moxifloxacin group and 81.4% (140/172) in the amoxicillin/clavulanate group (95% CI -12.96, 4.41). Staphylococcus aureus (137 isolates) and Escherichia coli (50 isolates) were the most frequently isolated skin pathogens. Adverse event rates were comparable between treatment groups. Conclusions: Treatment with sequential iv/po moxifloxacin monotherapy once daily is clinically comparable to that with iv/po amoxicillin/clavulanate three times daily in the management of cSSSIs. Moxiftoxacin's simple dose regimen offers an advantage over amoxicillin/clavulanate and represents a valuable addition to current antibiotic regimens used in the treatment of cSSSIs.