A randomized, double-blind, placebo- and positive-controlled crossover study of the effects of durlobactam on cardiac repolarization in healthy subjects

Abstract

Durlobactam (formerly ETX2514) is a diazabicyclooctane β-lactamase inhibitor that inhibits class A, C, and D β-lactamases. Sulbactam combined with durlobactam has in vitro and in vivo activity against Acinetobacter baumannii including carbapenem- and colistin-resistant isolates and is being developed for treating serious infections due to A. baumannii. The effect of a single supratherapeutic dose of durlobactam on the heart rate corrected QT interval (QTc) was evaluated in healthy subjects in a placebo- and active-controlled, single-infusion, three-way crossover study. Subjects were randomized to 1 of 6 sequences that included a single 3-h i.v. infusion of durlobactam 4 g (supratherapeutic dose), a single 3-h i.v. infusion of placebo, and a single 3-h i.v. infusion of placebo plus a single oral dose of moxifloxacin 400 mg given open-label at the end of the i.v. infusion. In each treatment period, Holter electrocardiogram (ECG) measurements were obtained from predose through 24 h post-start of infusion. For the primary ECG end point, placebo-corrected change-from-baseline corrected QT Fridericia's formula (ΔΔQTcF), no significant change was observed with durlobactam. A concentration-QT analysis demonstrated no significant effect of durlobactam on ECG parameters, including QT interval prolongation. Thus, durlobactam has a low risk for prolonging the QT interval and is unlikely to produce any proarrhythmic effects.