Journal Article

A randomized phase 2B trial of vancomycin versus daptomycin for the treatment of methicillin-resistant Staphylococcus aureus bacteremia due to isolates with high vancomycin minimum inhibitory concentrations – results of a prematurely terminated study

Ong, Siew Pei, Tan, Thuan Tong, Lye, David Chien, Phillips, Rachel, Low, Jenny G. H., Kalimuddin, Shirin, Archuleta, Sophia, Chan, Yvonne F. Z.

2018

Overview

Background Studies have suggested the reduced effectiveness of vancomycin against methicillin-resistant Staphylococcus aureus (MRSA) bloodstream infections with high vancomycin minimum inhibitory concentrations. Alternative agents such as daptomycin may be considered. We conducted a randomized controlled study comparing daptomycin against vancomycin in the treatment of MRSA bloodstream infections with high vancomycin minimum inhibitory concentrations. Methods Patients were randomized to receive vancomycin or daptomycin for a minimum of 14 days. The primary end point was the rate of all-cause mortality at day 60. Results A total of 14 patients were randomized in this study, with 7 patients in each treatment arm. The study was terminated early due to slow patient accrual. At day 60, there was one death in the vancomycin arm and none in the daptomycin arm. The median time to microbiological clearance was 4 days in both arms (IQR 3–5 days in the vancomycin arm and 3–7 days in daptomycin arm). Only one patient in the vancomycin arm had recurrence of bacteremia. Rates of adverse events were similar in both arms. There was one case of musculoskeletal toxicity and one case of drug-related nephrotoxicity - both events occurred in the daptomycin arm. None of the patients in either treatment arm required cessation of study treatment or addition of a second anti-MRSA agent because of worsening infection. Conclusion Based on the limited number of patients evaluated in this study, it remains unclear if alternative, more expensive agents such as daptomycin are superior to vancomycin in the treatment of high vancomycin minimum inhibitory concentration MRSA bloodstream infections. More studies are urgently needed but investigators may wish to consider employing novel, alternative trial methodologies to ensure a greater chance of success. Trial registration ClinicalTrials.gov, NCT01975662 . Registered on 5 November 2013.

• Publisher: BioMed Central,BioMed Central Ltd,Springer Nature B.V,BMC
• Subject: Aged / Anti-Bacterial Agents - administration & dosage / Anti-Bacterial Agents - adverse effects / Antibiotics / Bacteremia / Bacteremia - diagnosis / Bacteremia - drug therapy / Bacteremia - microbiology / Bacteremia - mortality / Biomedicine / Cause of Death / Comparative analysis / Creatinine / Daptomycin / Daptomycin - administration & dosage / Daptomycin - adverse effects / Drug dosages / Drug Resistance, Bacterial / Drug therapy / Early Termination of Clinical Trials / Endocarditis / Female / Health Sciences / Humans / Laboratories / Male / Medicine / Medicine & Public Health / Methicillin-resistant Staphylococcus aureus / Methicillin-Resistant Staphylococcus aureus - drug effects / Methicillin-Resistant Staphylococcus aureus - growth & development / Methicillin-Resistant Staphylococcus aureus - pathogenicity / Microbial Sensitivity Tests / Middle Aged / Minimum inhibitory concentration / Mortality / Patient outcomes / Pharmacists / Predictive Value of Tests / Recurrence / Singapore / Staphylococcal Infections - diagnosis / Staphylococcal Infections - drug therapy / Staphylococcal Infections - microbiology / Staphylococcal Infections - mortality / Staphylococcus aureus infections / Staphylococcus infections / Statistics for Life Sciences / Time Factors / Treatment Outcome / Vancomycin / Vancomycin - administration & dosage / Vancomycin - adverse effects