INTRODUCTION
ESBLs, ESKAPE, Gram-negative
The worldwide escalation of resistance to antibiotics among Gram-negative bacteria, particularly members of the ESKAPE group of pathogens (Ceftibuten is a cephalosporin antibiotic approved in the USA (The pharmacokinetics (PK) of ceftibuten has been characterized in single- and multiple-dose studies in the range of 25–800 mg (Qpex Biopharma (San Diego, CA, USA) is developing a fixed combination antibiotic of ceftibuten (QPX2015) with a new β-lactamase inhibitor (xeruborbactam, formerly QPX7728). Xeruborbactam can be given both intravenously and orally (in prodrug form), and has inhibitory activity against ESBLs and carbapenemases, including both serine and metallo-β-lactamases (The aim of this study is to describe the PK, safety and tolerability of single and multiple oral doses of ceftibuten administered to healthy adult subjects at doses higher than the 400 mg once-daily approved in the USA.