Short-term Safety, Tolerability, and Pharmacokinetics of MRX-I, an Oxazolidinone Antibacterial Agent, in Healthy Chinese Subjects

Purpose: This study was designed to evaluate the safety and pharmacokinetic profiles of MRX-I tablet, an oxazolidinone antibacterial agent, in healthy Chinese subjects. Methods: The study was composed of 3 sequential periods. Period 1 was a randomized, double-blind, placebo-controlled, sequential ascending dose (50 to 1800 mg) study. Period 2 included one arm as a randomized, open-label, 3-period, 3 x 3 Latin square single-dose study of 300, 600, and 900 mg MRX-I administration and another arm as a crossover study to evaluate high-fat diet effect. Period 3 was a randomized, double-blind, placebo-controlled multiple-dose study with 600 or 800 mg, q12h regimens over 15 days. Findings: MRX-I was rapidly absorbed and reached peak plasma concentration at about 2 hours post dose. The C-max was 8.07, 12.24, and 15.25 mg/L and the corresponding AUC(0-infinity) 29.21, 48.27, and 59.60 mg/h/L, in 300-, 600-, and 900-mg dosing groups, respectively. High-fat diet increased the exposure of MRX-I. No discernable drug accumulation was observed after 15 days of continuous drug administration. About 2% of MRX-I was excreted via kidneys in unchanged form. No obvious hematologic toxicity by MRX-I was observed during the entire study. Based on Monte Carlo simulation, 600 or 800 mg BID can produce satisfactory efficacy against methicillin-resistant Staphylococcus aureus. (C) 2018 Elsevier HS Journals, Inc. All rights reserved.