A noninferiority study of tedizolid phosphate provides information on this new antibiotic, as well as insights into both study design and treatment duration for skin infections.

Given the detrimental effects of antimicrobial therapy both in promoting antibiotic resistance and in altering the microbiome, shortening the duration of treatment for common infections is potentially beneficial. In a recent manufacturer-sponsored, multinational, phase III, double-blind, double-dummy trial, researchers compared a 6-day course of tedizolid phosphate — a novel oxazolidinone — with a 10-day course of linezolid for acute bacterial skin and skin-structure infections (ABSSSIs).

A total of 667 adults with ABSSSIs were randomized to receive 200 mg of oral tedizolid once daily for 6 days or 600 mg of oral linezolid twice daily for 10 days. In intent-to-treat analysis, tedizolid was noninferior to linezolid as determined at 48- to 72-hour clinical assessment (the primary efficacy outcome; 79.5% vs. 79.4%), as well as at the end of therapy (day 11; 69.3% vs. 71.9%) and 7 to 14 days later (85.5% vs. 86.0%). The posttherapy clinical response rate was high (85%) and similar between groups in the 178 patients (26.7%) with infections caused by methicillin-resistant Staphylococcus aureus.

Comment: As noted by the authors and editorialists, this study provides information both on tedizolid phosphate and on new FDA guidelines for assessing the efficacy of antibiotic therapy for ABSSSIs. It also highlights the need for clinical trials of currently approved agents to determine what treatment duration is really necessary for such infections.

Source: Journal Watch Infectious Diseases.