GlaxoSmithKline has announced the start of a Phase III clinical trial assessing gepotidacin; the first in a new chemical class of antibiotics called triazaacenaphthylene bacterial topoisomerase inhibitors.

The experimental antibiotic is being evaluated in patients with uncomplicated urinary tract infection (uUTI, also known as acute cystitis) and urogenital gonorrhoea (GC).

The programme, which comprises of two separate studies - EAGLE-1 and EAGLE-2 - will test gepotidacin in two common infections caused by bacteria identified as antibiotic resistant threats by the Centers for Disease Control and Prevention, a division of the US Department of Health and Human Services.

EAGLE-1 is set to compare gepotidacin to ceftriaxone in combination with azithromycin in approximately 600 patients with GC, one of the most common sexually transmitted infections.

EAGLE-2 will compare the drug to nitrofurantoin, a licensed first-line antibiotic, in approximately 1200 patients with uUTI, with results from both studies expected by the end of 2021.

The Phase III stage of the trials follows positive results from two Phase II trials, which showed that single, oral doses of gepotidacin were at least 95% effective for bacterial eradication of Neisseria gonorrhoea (NG) in adult participants with uncomplicated urogenital gonorrhoea.

“Given the increasing rate of antibiotic drug resistance, and gepotidacin’s unique mechanism of action, we believe this drug has the potential to transform the treatment landscape for patients with uncomplicated urinary tract infection and urogenital gonorrhoea who currently have limited therapeutic options,” explained Dr Hal Barron, chief scientific officer, R&D.

Gepotidacin works by selectively interacting with two key bacterial enzymes, DNA gyrase and topoisomerase IV (type II topoisomerases), responsible for bacterial replication.