Plazomicin was noninferior to meropenem, a carbapenem for the treatment of complicated urinary tract antibiotics (UTIs) and acute pyelonephritis caused by Enterobacteriaceae, including multidrug-resistant strains in a study published February 21, 2019 in the New England Journal of Medicine.
Plazomicin is a new aminoglycoside antibiotic.
In the study, more than 600 patients with complicated UTIs were randomized in a 1:1 ratio to receive intravenous plazomicin (15 mg/kg once daily) or meropenem (1 g every 8 hours), with optional oral step-down therapy after at least 4 days of IV therapy, for 7-10 days.
Plazomicin was noninferior to meropenem with respect to the primary efficacy end points of the study.
- Composite cure (clinical cure and microbiologic eradication) at day 5 was observed in 88% of patients in the plazomicin group vs 91.4% in the meropenem group.
- At the test-of-cure visit (15 to 19 days after initiation of therapy), composite cure was observed in 81.7% and 70.1%, respectively
- Microbiologic eradication, including eradication of Enterobacteriaceae that were not susceptible to aminoglycosides was higher in the plazomicin group vs meropenem group; 78.8% vs. 68.6%, respectively) and Enterobacteriaceae that produce extended-spectrum β-lactamases (ESBL); 82.4% vs. 75.0%, respectively.
- Fewer patients in the plazomicin group had microbiologic recurrence (3.7% vs. 8.1%) or clinical relapse (1.6% vs. 7.1%) vs meropenem group.
Both plazomicin and meropenem were well-tolerated; increase in serum creatinine levels was uncommon but higher with plazomicin.
These findings suggest plazomicin as a short duration intravenous alternative for outpatients who cannot take ertapenem for complicated UTI when there is risk of ESBL-producing organisms