Abstract: AIM: To design a clinical trial of non-inferiority for treating acute bacterial infections by an example and quantitively analyze the results. METHODS: A randomized, double-blind, multicenter, parallel controlled, and non-inferiority study was designed to compare the efficacy and safety of antofloxacin hydrochloride (200 mg, qd) and levofloxacin (200 mg, q12 h) (n =360). The oral administration lasted 7-14 days.The main end point was clinical efficacy rates. The margin of non-inferiority was 0.15 (15 %). RESULTS: After 7-14 days of treatment, no significant difference was found between the two groups either in the efficacy rate (antofloxacin hydrochloride: 95.1 %, Levofloxacin: 96.6 %, treatment difference,-0.015; 95 % confidence interval [CI] for the difference,-0.045 to 0.015) or the incidence of adverse reactions (antofloxacin hydrochloride: 8.1 %, levofloxacin: 8.1 %). CONCLUSION: Antofloxacin hydrochloride is non-inferior to levofloxacin, and well tolerated in the treatment of acute bacterial infections.

Key words: antofloxacin hydrochloride, levofloxacin, acute bacterial infections, clinical trials, non-inferiority study